National Library of Energy BETA

Sample records for groundwater flow model

  1. Oahu Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for the island of Oahu. Data is from the following sources: Rotzoll, K., A.I. El-Kadi. 2007. Numerical Ground-Water Flow Simulation for Red Hill Fuel Storage Facilities, NAVFAC Pacific, Oahu, Hawaii - Prepared TEC, Inc. Water Resources Research Center, University of Hawaii, Honolulu.; Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume VII – Island of Oahu Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008.; and Whittier, R. and A.I. El-Kadi. 2009. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. December 2009.

  2. Kauai Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for Kauai. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume IV – Island of Kauai Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2015.

  3. Kauai Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for Kauai. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report Volume IV Island of Kauai Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2015.

  4. East Maui Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for East Maui. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume V – Island of Maui Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008.

  5. Hawaii Island Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for Hawaii Island. Data is from the following sources: Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume II – Island of Hawaii Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008; and Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.

  6. West Maui Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for West Maui. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume V – Island of Maui Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008.

  7. West Maui Groundwater Flow Model

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nicole Lautze

    2015-01-01

    Groundwater flow model for West Maui. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report Volume V Island of Maui Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008.

  8. A Guide for Using the Transient Ground-Water Flow Model of the Death Valley Regional Ground-Water Flow System, Nevada and California

    SciTech Connect (OSTI)

    Joan B. Blainey; Claudia C. Faunt, and Mary C. Hill

    2006-05-16

    This report is a guide for executing numerical simulations with the transient ground-water flow model of the Death Valley regional ground-water flow system, Nevada and California using the U.S. Geological Survey modular finite-difference ground-water flow model, MODFLOW-2000. Model inputs, including observations of hydraulic head, discharge, and boundary flows, are summarized. Modification of the DVRFS transient ground-water model is discussed for two common uses of the Death Valley regional ground-water flow system model: predictive pumping scenarios that extend beyond the end of the model simulation period (1998), and model simulations with only steady-state conditions.

  9. Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model

    SciTech Connect (OSTI)

    Cole, Charles R.; Bergeron, Marcel P.; Murray, Christopher J.; Thorne, Paul D.; Wurstner, Signe K.; Rogers, Phillip M.

    2001-11-09

    Pacific Northwest National Laboratory (PNNL) embarked on a new initiative to strengthen the technical defensibility of the predictions being made with a site-wide groundwater flow and transport model at the U.S. Department of Energy Hanford Site in southeastern Washington State. In FY 2000, the focus of the initiative was on the characterization of major uncertainties in the current conceptual model that would affect model predictions. The long-term goals of the initiative are the development and implementation of an uncertainty estimation methodology in future assessments and analyses using the site-wide model. This report focuses on the development and implementation of an uncertainty analysis framework.

  10. First status report on regional groundwater flow modeling for the Palo Duro Basin, Texas

    SciTech Connect (OSTI)

    Andrews, R.W.

    1984-12-01

    Regional groundwater flow within the principal hydrogeological units of the Palo Duro Basin is evaluated by developing a conceptual model of the flow regime in the shallow aquifers and the deep-basin brine aquifers and testing these models using a three-dimensional, finite-difference flow code. Semiquantitative sensitivity analysis (a limited parametric study) is conducted to define the system response to changes in hydrologic properties or boundary conditions. Adjoint sensitivity analysis is applied to the conceptualized flow regime in the Wolfcamp carbonate aquifer. All steps leading to the final results and conclusions are incorporated in this report. The available data utilized in this study are summarized. The specific conceptual models, defining the areal and vertical averaging of lithologic units, aquifer properties, fluid properties, and hydrologic boundary conditions, are described in detail. The results are delineated by the simulated potentiometric surfaces and tables summarizing areal and vertical boundary fluxes, Darcy velocities at specific points, and groundwater travel paths. Results from the adjoint sensitivity analysis included importance functions and sensitivity coefficients, using heads or the average Darcy velocities as the performance measures. The reported work is the first stage of an ongoing evaluation of two areas within the Palo Duro Basin as potantial repositories for high-level radioactive wastes. The results and conclusions should thus be considered preliminary and subject to modification with the collection of additional data. However, this report does provide a useful basis for describing the sensitivity and, to a lesser extent, the uncertainty of the present conceptualization of groundwater flow within the Palo Duro Basin.

  11. A Model For Syn-Eruptive Groundwater Flow During The Phreatoplinian...

    Open Energy Info (EERE)

    Syn-Eruptive Groundwater Flow During The Phreatoplinian Phase Of The 28-29 March 1875 Askja Volcano Eruption, Iceland Jump to: navigation, search OpenEI Reference LibraryAdd to...

  12. Monitoring probe for groundwater flow

    DOE Patents [OSTI]

    Looney, B.B.; Ballard, S.

    1994-08-23

    A monitoring probe for detecting groundwater migration is disclosed. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow. 4 figs.

  13. Monitoring probe for groundwater flow

    DOE Patents [OSTI]

    Looney, Brian B.; Ballard, Sanford

    1994-01-01

    A monitoring probe for detecting groundwater migration. The monitor features a cylinder made of a permeable membrane carrying an array of electrical conductivity sensors on its outer surface. The cylinder is filled with a fluid that has a conductivity different than the groundwater. The probe is placed in the ground at an area of interest to be monitored. The fluid, typically saltwater, diffuses through the permeable membrane into the groundwater. The flow of groundwater passing around the permeable membrane walls of the cylinder carries the conductive fluid in the same general direction and distorts the conductivity field measured by the sensors. The degree of distortion from top to bottom and around the probe is precisely related to the vertical and horizontal flow rates, respectively. The electrical conductivities measured by the sensors about the outer surface of the probe are analyzed to determine the rate and direction of the groundwater flow.

  14. Numerical Simulation of Inter-basin Groundwater Flow into Northern Yucca Flat, Nevada National Security Site, Using the Death Valley Regional Flow System Model

    SciTech Connect (OSTI)

    Pohlmann Karl,Ye Ming

    2012-03-01

    Models of groundwater flow for the Yucca Flat area of the Nevada National Security Site (NNSS) are under development by the U.S. Department of Energy (DOE) for corrective action investigations of the Yucca Flat-Climax Mine Corrective Action Unit (CAU). One important aspect of these models is the quantity of inter-basin groundwater flow from regional systems to the north. This component of flow, together with its uncertainty, must be properly accounted for in the CAU flow models to provide a defensible regional framework for calculations of radionuclide transport that will support determinations of the Yucca Flat-Climax Mine contaminant boundary. Because characterizing flow boundary conditions in northern Yucca Flat requires evaluation to a higher level of detail than the scale of the Yucca Flat-Climax Mine CAU model can efficiently provide, a study more focused on this aspect of the model was required.

  15. Thermal effects of groundwater flow through subarctic fens: A case study based on field observations and numerical modeling

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sjöberg, Ylva; Coon, Ethan; K. Sannel, A. Britta; Pannetier, Romain; Harp, Dylan; Frampton, Andrew; Painter, Scott L.; Lyon, Steve W.

    2016-02-05

    Modeling and observation of ground temperature dynamics are the main tools for understanding current permafrost thermal regimes and projecting future thaw. Until recently, most studies on permafrost have focused on vertical ground heat fluxes. Groundwater can transport heat in both lateral and vertical directions but its influence on ground temperatures at local scales in permafrost environments is not well understood. In this paper, we combine field observations from a subarctic fen in the sporadic permafrost zone with numerical simulations of coupled water and thermal fluxes. At the Tavvavuoma study site in northern Sweden, ground temperature profiles and groundwater levels weremore » observed in boreholes. These observations were used to set up one- and two-dimensional simulations down to 2 m depth across a gradient of permafrost conditions within and surrounding the fen. Two-dimensional scenarios representing the fen under various hydraulic gradients were developed to quantify the influence of groundwater flow on ground temperature. Our observations suggest that lateral groundwater flow significantly affects ground temperatures. This is corroborated by modeling results that show seasonal ground ice melts 1 month earlier when a lateral groundwater flux is present. Further, although the thermal regime may be dominated by vertically conducted heat fluxes during most of the year, isolated high groundwater flow rate events such as the spring freshet are potentially important for ground temperatures. Finally, as sporadic permafrost environments often contain substantial portions of unfrozen ground with active groundwater flow paths, knowledge of this heat transport mechanism is important for understanding permafrost dynamics in these environments.« less

  16. Understanding heat and groundwater flow through continental flood basalt provinces: insights gained from alternative models of permeability/depth relationships for the Columbia Plateau, USA

    SciTech Connect (OSTI)

    Burns, Erick R.; Williams, Colin F.; Ingebritsen, Steven E.; Voss, Clifford I.; Spane, Frank A.; DeAngelo, Jacob

    2015-02-01

    Heat-flow mapping of the western USA has identified an apparent low-heat-flow anomaly coincident with the Columbia Plateau Regional Aquifer System, a thick sequence of basalt aquifers within the Columbia River Basalt Group (CRBG). A heat and mass transport model (SUTRA) was used to evaluate the potential impact of groundwater flow on heat flow along two different regional groundwater flow paths. Limited in situ permeability (k) data from the CRBG are compatible with a steep permeability decrease (approximately 3.5 orders of magnitude) at 600–900 m depth and approximately 40°C. Numerical simulations incorporating this permeability decrease demonstrate that regional groundwater flow can explain lower-than-expected heat flow in these highly anisotropic (kx/kz ~ 104) continental flood basalts. Simulation results indicate that the abrupt reduction in permeability at approximately 600 m depth results in an equivalently abrupt transition from a shallow region where heat flow is affected by groundwater flow to a deeper region of conduction-dominated heat flow. Most existing heat-flow measurements within the CRBG are from shallower than 600 m depth or near regional groundwater discharge zones, so that heat-flow maps generated using these data are likely influenced by groundwater flow. Substantial k decreases at similar temperatures have also been observed in the volcanic rocks of the adjacent Cascade Range volcanic arc and at Kilauea Volcano, Hawaii, where they result from low-temperature hydrothermal alteration.

  17. A groundwater flow and transport model of long-term radionuclide migration in central Frenchman flat, Nevada test site

    SciTech Connect (OSTI)

    Kwicklis, Edward Michael [Los Alamos National Laboratory; Becker, Naomi M [Los Alamos National Laboratory; Ruskauff, Gregory [NAVARRO-INTERA, LLC.; De Novio, Nicole [GOLDER AND ASSOC.; Wilborn, Bill [US DOE NNSA NSO

    2010-11-10

    A set of groundwater flow and transport models were created for the Central Testing Area of Frenchman Flat at the former Nevada Test Site to investigate the long-term consequences of a radionuclide migration experiment that was done between 1975 and 1990. In this experiment, radionuclide migration was induced from a small nuclear test conducted below the water table by pumping a well 91 m away. After radionuclides arrived at the pumping well, the contaminated effluent was discharged to an unlined ditch leading to a playa where it was expected to evaporate. However, recent data from a well near the ditch and results from detailed models of the experiment by LLNL personnel have convincingly demonstrated that radionuclides from the ditch eventually reached the water table some 220 m below land surface. The models presented in this paper combine aspects of these detailed models with concepts of basin-scale flow to estimate the likely extent of contamination resulting from this experiment over the next 1,000 years. The models demonstrate that because regulatory limits for radionuclide concentrations are exceeded only by tritium and the half-life of tritium is relatively short (12.3 years), the maximum extent of contaminated groundwater has or will soon be reached, after which time the contaminated plume will begin to shrink because of radioactive decay. The models also show that past and future groundwater pumping from water supply wells within Frenchman Flat basin will have negligible effects on the extent of the plume.

  18. Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 0

    SciTech Connect (OSTI)

    Drici, Warda

    2003-08-01

    This report documents the analysis of the available transport parameter data conducted in support of the development of a Corrective Action Unit (CAU) groundwater flow model for Central and Western Pahute Mesa: CAUs 101 and 102.

  19. Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 0

    SciTech Connect (OSTI)

    Drici, Warda

    2004-02-01

    This report documents the analysis of the available hydrologic data conducted in support of the development of a Corrective Action Unit (CAU) groundwater flow model for Central and Western Pahute Mesa: CAUs 101 and 102.

  20. Modeling of Groundwater Flow and Radionuclide Transport at the Climax Mine sub-CAU, Nevada Test Site

    SciTech Connect (OSTI)

    K. Pohlmann; M. Ye; D. Reeves; M. Zavarin; D. Decker; J. Chapman

    2007-09-28

    The Yucca Flat-Climax Mine Corrective Action Unit (CAU) on the Nevada Test Site comprises 747 underground nuclear detonations, all but three of which were conducted in alluvial, volcanic, and carbonate rocks in Yucca Flat. The remaining three tests were conducted in the very different hydrogeologic setting of the Climax Mine granite stock located in Area 15 at the northern end of Yucca Flat. As part of the Corrective Action Investigation (CAI) for the Yucca Flat-Climax Mine CAU, models of groundwater flow and radionuclide transport will be developed for Yucca Flat. However, two aspects of these CAU-scale models require focused modeling at the northern end of Yucca Flat beyond the capability of these large models. First, boundary conditions and boundary flows along the northern reaches of the Yucca Flat-Climax Mine CAU require evaluation to a higher level of detail than the CAU-scale Yucca Flat model can efficiently provide. Second, radionuclide fluxes from the Climax tests require analysis of flow and transport in fractured granite, a unique hydrologic environment as compared to Yucca Flat proper. This report describes the Climax Mine sub-CAU modeling studies conducted to address these issues, with the results providing a direct feed into the CAI for the Yucca Flat-Climax Mine CAU. Three underground nuclear detonations were conducted for weapons effects testing in the Climax stock between 1962 and 1966: Hard Hat, Pile Driver, and Tiny Tot. Though there is uncertainty regarding the position of the water table in the stock, it is likely that all three tests were conducted in the unsaturated zone. In the early 1980s, the Spent Fuel Test-Climax (SFT-C) was constructed to evaluate the feasibility of retrievable, deep geologic storage of commercial nuclear reactor wastes. Detailed mapping of fractures and faults carried out for the SFT-C studies greatly expanded earlier data sets collected in association with the nuclear tests and provided invaluable information for

  1. Phase II Groundwater Flow Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    John McCord

    2006-05-01

    The Phase II Frenchman Flat groundwater flow model is a key element in the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996) corrective action strategy for the Underground Test Area (UGTA) Frenchman Flat corrective action unit (CAU). The objective of this integrated process is to provide an estimate of the vertical and horizontal extent of contaminant migration for each CAU to predict contaminant boundaries. A contaminant boundary is the model-predicted perimeter that defines the extent of radionuclide-contaminated groundwater from underground testing above background conditions exceeding the ''Safe Drinking Water Act'' (SDWA) standards. The contaminant boundary will be composed of both a perimeter boundary and a lower hydrostratigraphic unit (HSU) boundary. The computer model will predict the location of this boundary within 1,000 years and must do so at a 95 percent level of confidence. Additional results showing contaminant concentrations and the location of the contaminant boundary at selected times will also be presented. These times may include the verification period, the end of the five-year proof-of-concept period, as well as other times that are of specific interest. This report documents the development and implementation of the groundwater flow model for the Frenchman Flat CAU. Specific objectives of the Phase II Frenchman Flat flow model are to: (1) Incorporate pertinent information and lessons learned from the Phase I Frenchman Flat CAU models. (2) Develop a three-dimensional (3-D), mathematical flow model that incorporates the important physical features of the flow system and honors CAU-specific data and information. (3) Simulate the steady-state groundwater flow system to determine the direction and magnitude of groundwater fluxes based on calibration to Frenchman Flat hydrogeologic data. (4) Quantify the uncertainty in the direction and magnitude of groundwater flow due to uncertainty in parameter values and alternative component

  2. Validation, Proof-of-Concept, and Postaudit of the Groundwater Flow and Transport Model of the Project Shoal Area

    SciTech Connect (OSTI)

    Ahmed Hassan

    2004-09-01

    The groundwater flow and radionuclide transport model characterizing the Shoal underground nuclear test has been accepted by the State of Nevada Division of Environmental Protection. According to the Federal Facility Agreement and Consent Order (FFACO) between DOE and the State of Nevada, the next steps in the closure process for the site are then model validation (or postaudit), the proof-of-concept, and the long-term monitoring stage. This report addresses the development of the validation strategy for the Shoal model, needed for preparing the subsurface Corrective Action Decision Document-Corrective Action Plan and the development of the proof-of-concept tools needed during the five-year monitoring/validation period. The approach builds on a previous model, but is adapted and modified to the site-specific conditions and challenges of the Shoal site.

  3. Integrated hydrogeological model of the general separations area. Volume 2: groundwater flow model

    SciTech Connect (OSTI)

    Flach, G.P.; Harris, M.K.

    1997-08-01

    This report models the Gordon aquifer, the Gordon confining unit, and the `lower` aquifer zone, `tan clay` confining zone, and `upper` aquifer zone of the Water Table aquifer. The report presents structure-contour and isopach maps of each unit.

  4. Application of Maximum Likelihood Bayesian Model Averaging to Groundwater Flow and Transport at the Hanford Site 300 Area

    SciTech Connect (OSTI)

    Meyer, Philip D.; Ye, Ming; Neuman, Shlomo P.; Rockhold, Mark L.

    2008-06-01

    A methodology to systematically and quantitatively assess model predictive uncertainty was applied to saturated zone uranium transport at the 300 Area of the U.S. Department of Energy Hanford Site in Washington State, USA. The methodology extends Maximum Likelihood Bayesian Model Averaging (MLBMA) to account jointly for uncertainties due to the conceptual-mathematical basis of models, model parameters, and the scenarios to which the models are applied. Conceptual uncertainty was represented by postulating four alternative models of hydrogeology and uranium adsorption. Parameter uncertainties were represented by estimation covariances resulting from the joint calibration of each model to observed heads and uranium concentration. Posterior model probability was dominated by one model. Results demonstrated the role of model complexity and fidelity to observed system behavior in determining model probabilities, as well as the impact of prior information. Two scenarios representing alternative future behavior of the Columbia River adjacent to the site were considered. Predictive simulations carried out with the calibrated models illustrated the computation of model- and scenario-averaged predictions and how results can be displayed to clearly indicate the individual contributions to predictive uncertainty of the model, parameter, and scenario uncertainties. The application demonstrated the practicability of applying a comprehensive uncertainty assessment to large-scale, detailed groundwater flow and transport modelling.

  5. A three-dimensional numerical model of predevelopment conditions in the Death Valley regional ground-water flow system, Nevada and California

    SciTech Connect (OSTI)

    D'Agnese, F.A.; O'Brien, G.M.; Faunt, C.C.; Belcher, W.R.; San Juan, Carma

    2002-11-22

    In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration.

  6. Structure and Groundwater Flow in the Espanola Basin Near Rio...

    Office of Environmental Management (EM)

    Structure and Groundwater Flow in the Espanola Basin Near Rio Grande and Buckman Wellfield Structure and Groundwater Flow in the Espanola Basin Near Rio Grande and Buckman...

  7. Phase II Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    John McCord

    2004-12-01

    This report documents pertinent hydrologic data and data analyses as part of the Phase II Corrective Action Investigation (CAI) for Frenchman Flat (FF) Corrective Action Unit (CAU): CAU 98. The purpose of this data compilation and related analyses is to provide the primary reference to support the development of the Phase II FF CAU groundwater flow model.

  8. Tracer advection by steady groundwater flow in a stratified aquifer

    SciTech Connect (OSTI)

    Sposito, Garrison; Weeks, Scott W.

    1997-01-02

    The perfectly stratified aquifer has often been investigated as a simple, tractable model for exploring new theoretical issues in subsurface hydrology. Adopting this approach, we show that steady groundwater flows in the perfectly stratified aquifer are always confined to a set of nonintersecting permanent surfaces, on which both streamlines and vorticity lines lie. This foliation of the flow domain exists as well for steady groundwater flows in any isotropic, spatially heterogeneous aquifer. In the present model example it is a direct consequence of the existence of a stream function, we then demonstrate that tracer plume advection by steady groundwater flow in a perfectly stratified aquifer is never ergodic, regardless of the initial size of the tracer plume. This nonergodicity, which holds also for tracer advection in any isotropic, spatially heterogeneous aquifer, implies that stochastic theories of purely advective tracer plume movement err in assuming ergodic behavior to simplify probabilistic calculations of plume spatial concentration moments.

  9. Numerical modeling of regional ground-water flow in the deep-basin brine aquifer of the Palo Duro Basin, Texas Panhandle

    SciTech Connect (OSTI)

    Wirojanagud, P.; Kreitler, C.W.; Smith, D.A.

    1986-01-01

    Bedded Permian-age evaporite sequences in the Palo Duro Basin are being considered for a permanent nuclear waste repository by the U.S. Department of Energy. The purpose of this modeling study is to provide an understanding of regional ground-water flow in the formations beneath the Permian evaporite section. From this understanding, more detailed, smaller scale studies can be designed. This study is also intended to provide a better understanding of the boundary conditions and permeabilities of the aquifer and aquitard system as well as provide estimates of ground-water travel times across the basin. Numerical simulations were made of the Wolfcamp aquifer modeled as a single layer and of the entire Deep-Basin Brine aquifer system, including the Wolfcamp aquifer, modeled as a single layer.

  10. Flow calculations for Yucca Mountain groundwater travel time (GWTT-95)

    SciTech Connect (OSTI)

    Altman, S.J.; Arnold, B.W.; Barnard, R.W.; Barr, G.E.; Ho, C.K.; McKenna, S.A.; Eaton, R.R.

    1996-09-01

    In 1983, high-level radioactive waste repository performance requirements related to groundwater travel time were defined by NRC subsystem regulation 10 CFR 60.113. Although DOE is not presently attempting to demonstrate compliance with that regulation, understanding of the prevalence of fast paths in the groundwater flow system remains a critical element of any safety analyses for a potential repository system at Yucca Mountain, Nevada. Therefore, this analysis was performed to allow comparison of fast-path flow against the criteria set forth in the regulation. Models developed to describe the conditions for initiation, propagation, and sustainability of rapid groundwater movement in both the unsaturated and saturated zones will form part of the technical basis for total- system analyses to assess site viability and site licensability. One of the most significant findings is that the fastest travel times in both unsaturated and saturated zones are in the southern portion of the potential repository, so it is recommended that site characterization studies concentrate on this area. Results support the assumptions regarding the importance of an appropriate conceptual model of groundwater flow and the incorporation of heterogeneous material properties into the analyses. Groundwater travel times are sensitive to variation/uncertainty in hydrologic parameters and in infiltration flux at upper boundary of the problem domain. Simulated travel times are also sensitive to poorly constrained parameters of the interaction between flow in fractures and in the matrix.

  11. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    SciTech Connect (OSTI)

    J.M. Thomas; F.C. Benedict, Jr.; T.P. Rose; R.L. Hershey; J.B. Paces; Z.E. Peterman; I.M. Farnham; K.H. Johannesson; A.K. Singh; K.J. Stetzenbach; G.B. Hudson; J.M. Kenneally; G.F. Eaton; D.K. Smith

    2003-01-08

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units.

  12. A Hydrostrat Model and Alternatives for Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainer Mesa-Shoshone Mountain, Nye County, Nevada

    SciTech Connect (OSTI)

    NSTec Geotechnical Sciences Group

    2007-03-01

    The three-dimensional hydrostratigraphic framework model for the Rainier Mesa-Shoshone Mountain Corrective Action Unit was completed in Fiscal Year 2006. The model extends from eastern Pahute Mesa in the north to Mid Valley in the south and centers on the former nuclear testing areas at Rainier Mesa, Aqueduct Mesa, and Shoshone Mountain. The model area also includes an overlap with the existing Underground Test Area Corrective Action Unit models for Yucca Flat and Pahute Mesa. The model area is geologically diverse and includes un-extended yet highly deformed Paleozoic terrain and high volcanic mesas between the Yucca Flat extensional basin on the east and caldera complexes of the Southwestern Nevada Volcanic Field on the west. The area also includes a hydrologic divide between two groundwater sub-basins of the Death Valley regional flow system. A diverse set of geological and geophysical data collected over the past 50 years was used to develop a structural model and hydrostratigraphic system for the model area. Three deep characterization wells, a magnetotelluric survey, and reprocessed gravity data were acquired specifically for this modeling initiative. These data and associated interpretive products were integrated using EarthVision{reg_sign} software to develop the three-dimensional hydrostratigraphic framework model. Crucial steps in the model building process included establishing a fault model, developing a hydrostratigraphic scheme, compiling a drill-hole database, and constructing detailed geologic and hydrostratigraphic cross sections and subsurface maps. The more than 100 stratigraphic units in the model area were grouped into 43 hydrostratigraphic units based on each unit's propensity toward aquifer or aquitard characteristics. The authors organized the volcanic units in the model area into 35 hydrostratigraphic units that include 16 aquifers, 12 confining units, 2 composite units (a mixture of aquifer and confining units), and 5 intrusive confining

  13. A Hydrostratigraphic System for Modeling Groundwater Flow and Radionuclide Migration at the Corrective Action Unit Scale, Nevada Test Site and Surrounding Areas, Clark, Lincoln, and Nye Counties, Nevada

    SciTech Connect (OSTI)

    Prothro, Lance; Drellack Jr., Sigmund; Mercadante, Jennifer

    2009-01-31

    Underground Test Area (UGTA) corrective action unit (CAU) groundwater flow and contaminant transport models of the Nevada Test Site (NTS) and vicinity are built upon hydrostratigraphic framework models (HFMs) that utilize the hydrostratigraphic unit (HSU) as the fundamental modeling component. The delineation and three-dimensional (3-D) modeling of HSUs within the highly complex geologic terrain that is the NTS requires a hydrostratigraphic system that is internally consistent, yet flexible enough to account for overlapping model areas, varied geologic terrain, and the development of multiple alternative HFMs. The UGTA CAU-scale hydrostratigraphic system builds on more than 50 years of geologic and hydrologic work in the NTS region. It includes 76 HSUs developed from nearly 300 stratigraphic units that span more than 570 million years of geologic time, and includes rock units as diverse as marine carbonate and siliciclastic rocks, granitic intrusives, rhyolitic lavas and ash-flow tuffs, and alluvial valley-fill deposits. The UGTA CAU-scale hydrostratigraphic system uses a geology-based approach and two-level classification scheme. The first, or lowest, level of the hydrostratigraphic system is the hydrogeologic unit (HGU). Rocks in a model area are first classified as one of ten HGUs based on the rock’s ability to transmit groundwater (i.e., nature of their porosity and permeability), which at the NTS is mainly a function of the rock’s primary lithology, type and degree of postdepositional alteration, and propensity to fracture. The second, or highest, level within the UGTA CAU-scale hydrostratigraphic system is the HSU, which is the fundamental mapping/modeling unit within UGTA CAU-scale HFMs. HSUs are 3-D bodies that are represented in the finite element mesh for the UGTA groundwater modeling process. HSUs are defined systematically by stratigraphically organizing HGUs of similar character into larger HSUs designations. The careful integration of

  14. Phase I Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nye County, Nevada, Revision 1

    SciTech Connect (OSTI)

    Nathan Bryant

    2008-05-01

    This document presents a summary and framework of the available hydrologic data and other information directly relevant to the development of the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU) 99 groundwater flow models. Where appropriate, data and information documented elsewhere are briefly summarized with reference to the complete documentation.

  15. Phase I Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    John McCord

    2006-06-01

    The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) initiated the Underground Test Area (UGTA) Project to assess and evaluate the effects of the underground nuclear weapons tests on groundwater beneath the Nevada Test Site (NTS) and vicinity. The framework for this evaluation is provided in Appendix VI, Revision No. 1 (December 7, 2000) of the Federal Facility Agreement and Consent Order (FFACO, 1996). Section 3.0 of Appendix VI ''Corrective Action Strategy'' of the FFACO describes the process that will be used to complete corrective actions specifically for the UGTA Project. The objective of the UGTA corrective action strategy is to define contaminant boundaries for each UGTA corrective action unit (CAU) where groundwater may have become contaminated from the underground nuclear weapons tests. The contaminant boundaries are determined based on modeling of groundwater flow and contaminant transport. A summary of the FFACO corrective action process and the UGTA corrective action strategy is provided in Section 1.5. The FFACO (1996) corrective action process for the Yucca Flat/Climax Mine CAU 97 was initiated with the Corrective Action Investigation Plan (CAIP) (DOE/NV, 2000a). The CAIP included a review of existing data on the CAU and proposed a set of data collection activities to collect additional characterization data. These recommendations were based on a value of information analysis (VOIA) (IT, 1999), which evaluated the value of different possible data collection activities, with respect to reduction in uncertainty of the contaminant boundary, through simplified transport modeling. The Yucca Flat/Climax Mine CAIP identifies a three-step model development process to evaluate the impact of underground nuclear testing on groundwater to determine a contaminant boundary (DOE/NV, 2000a). The three steps are as follows: (1) Data compilation and analysis that provides the necessary modeling data that is

  16. Results of two- and three-dimensional groundwater flow modeling for the design criteria studies in Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    SciTech Connect (OSTI)

    Not Available

    1993-12-01

    This report combines results from 2-D and 3-D groundwater flow simulations. An overview of the hydrogeologic setting of WAG 6 located at ORNL is presented followed by a discussion of the numerical models used. Model development is discussed for both the 3-D and 2-D models. Results are then presented for the 3-D models followed by results from the 2-D models. The report concludes with an integrated summary of conclusions. This report contains many figures because graphics are advantageous in effectively portraying modeling results.

  17. Addendum for the Phase II Groundwater Flow Model of Corrective Action Unit 98: Frenchman Flat, NevadaTest Site, Nye County, Nevada, Revision 0 (page changes)

    SciTech Connect (OSTI)

    John McCord

    2007-05-01

    This document, which makes changes to Phase II Groundwater Flow Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, S-N/99205--074, Revision 0 (May 2006) was prepared to address review comments on this final document provided by the Nevada Division of Environmental Protection (NDEP) in a letter dated June 20, 2006. The document includes revised pages that address NDEP review comments and comments from other document users. Change bars are included on these pages to identify where the text was revised. In addition to the revised pages, the following clarifications are made: Section 6.0 Conceptual Model Uncertainty Analyses. Please note that in this section figures showing the observed versus simulated well head (Figures 6-1, 6-5, 6-7, 6-16, 6-28, 6-30, 6-32, 6-34, 6-37, 6-42, 6-47, 6-52, 6-57, 6-62, 6-71, and 6-86) have a vertical break in scale on the y axis. Section 7.0 Parameter Sensitivity Analysis. In Section 7.2, the parameter perturbation analysis defines two components of the objective function PHI. These two components include the WELL component that represents the head portion of the objective function as measured in wells and the FLUX component that represents the lateral boundary flux portion of the objective function. In the text and figures in Section 7.2, the phrases well portion of the objective function and head portion of the objective function are used interchangeably in discussions of the WELL component of the objective function.

  18. The Underground Test Area Project of the Nevada Test Site: Building Confidence in Groundwater Flow and Transport Models at Pahute Mesa Through Focused Characterization Studies

    SciTech Connect (OSTI)

    Pawloski, G A; Wurtz, J; Drellack, S L

    2009-12-29

    Pahute Mesa at the Nevada Test Site contains about 8.0E+07 curies of radioactivity caused by underground nuclear testing. The Underground Test Area Subproject has entered Phase II of data acquisition, analysis, and modeling to determine the risk to receptors from radioactivity in the groundwater, establish a groundwater monitoring network, and provide regulatory closure. Evaluation of radionuclide contamination at Pahute Mesa is particularly difficult due to the complex stratigraphy and structure caused by multiple calderas in the Southwestern Nevada Volcanic Field and overprinting of Basin and Range faulting. Included in overall Phase II goals is the need to reduce the uncertainty and improve confidence in modeling results. New characterization efforts are underway, and results from the first year of a three-year well drilling plan are presented.

  19. Unsaturated Groundwater and Heat Transport Model

    Energy Science and Technology Software Center (OSTI)

    2008-05-15

    TOUGH2-MP is a massive parallel version of the TOUGH2 Code, designed for computationally efficient parallel simulation of isothermal and nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. The code runs on computers with parallel architecture or clusters and can be used for applications, such as radioactive waste disposal, CO2 geological sequestration, environmental assessment and remediation, reservoir engineering, and groundwater hydrology. The parallel simulator has achieved orders-of-the-magnitude improvement inmore » computational time and/or modeling problem size. The parallel simulator uses fully implicit time differencing and solves large, sparse linear systems arising from discretization of the partial differential equations for mass and energy balance. A domain decomposition approach is adopted for multiphase flow simulations with coarse- granularity parallel computation. Current version of TOUGH2-MP includes following modules: EOS1, EOS2, EOS3, EOS4, EOS5, EOS7, EOS7R, E0S8, EOS9, ECO2N, EWASG, and T2R3D.« less

  20. Bore II - Advanced Wellbore Technology Characterizes Groundwater Flow and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Contamination - Energy Innovation Portal Geothermal Geothermal Energy Analysis Energy Analysis Find More Like This Return to Search Bore II - Advanced Wellbore Technology Characterizes Groundwater Flow and Contamination Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing SummaryBore II, co-developed by Berkeley Lab researchers Frank Hale, Chin-Fu Tsang, and Christine Doughty, provides vital information for solving water quality and supply problems and

  1. Update to the Ground-Water Withdrawals Database for the Death Valley REgional Ground-Water Flow System, Nevada and California, 1913-2003

    SciTech Connect (OSTI)

    Michael T. Moreo; and Leigh Justet

    2008-07-02

    Ground-water withdrawal estimates from 1913 through 2003 for the Death Valley regional ground-water flow system are compiled in an electronic database to support a regional, three-dimensional, transient ground-water flow model. This database updates a previously published database that compiled estimates of ground-water withdrawals for 1913–1998. The same methodology is used to construct each database. Primary differences between the 2 databases are an additional 5 years of ground-water withdrawal data, well locations in the updated database are restricted to Death Valley regional ground-water flow system model boundary, and application rates are from 0 to 1.5 feet per year lower than original estimates. The lower application rates result from revised estimates of crop consumptive use, which are based on updated estimates of potential evapotranspiration. In 2003, about 55,700 acre-feet of ground water was pumped in the DVRFS, of which 69 percent was used for irrigation, 13 percent for domestic, and 18 percent for public supply, commercial, and mining activities.

  2. A preliminary assessment of the effects of groundwater flow on closed-loop ground source heat pump systems

    SciTech Connect (OSTI)

    Chiasson, A.D.; Rees, S.J.; Spitler, J.D.

    2000-07-01

    A preliminary study has been made of the effects of groundwater flow on the heat transfer characteristics of vertical closed-loop heat exchangers and the ability of current design and in-situ thermal conductivity measurement techniques to deal with these effects. It is shown that an initial assessment of the significance of groundwater flow can be made by examining the Peclet number of the flow. A finite-element numerical groundwater flow and heat transfer model has been used to simulate the effects of groundwater flow on a single closed-loop heat exchanger in various geologic materials. These simulations show that advection of heat by groundwater flow significantly enhances heat transfer in geologic materials with high hydraulic conductivity, such as sands, gravels, and rocks exhibiting fractures and solution channels. Simulation data were also used to derive effective thermal conductivities with an in-situ thermal conductivity estimation procedure. These data were used to design borehole fields of different depths for a small commercial building. The performance of these borehole field designs was investigated by simulating each borehole field using the pre-calculated building loads over a ten-year period. Results of these simulations, in terms of the minimum and peak loop temperatures, were used to examine the ability of current design methods to produce workable and efficient designs under a range of groundwater flow conditions.

  3. A Hydrostratigraphic Model and Alternatives for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat-Climax Mine, Lincoln and Nye Counties, Nevada

    SciTech Connect (OSTI)

    Geotechnical Sciences Group Bechtel Nevada

    2006-01-01

    A new three-dimensional hydrostratigraphic framework model for the Yucca Flat-Climax Mine Corrective Action Unit was completed in 2005. The model area includes Yucca Flat and Climax Mine, former nuclear testing areas at the Nevada Test Site, and proximal areas. The model area is approximately 1,250 square kilometers in size and is geologically complex. Yucca Flat is a topographically closed basin typical of many valleys in the Basin and Range province. Faulted and tilted blocks of Tertiary-age volcanic rocks and underlying Proterozoic and Paleozoic sedimentary rocks form low ranges around the structural basin. During the Cretaceous Period a granitic intrusive was emplaced at the north end of Yucca Flat. A diverse set of geological and geophysical data collected over the past 50 years was used to develop a structural model and hydrostratigraphic system for the basin. These were integrated using EarthVision? software to develop the 3-dimensional hydrostratigraphic framework model. Fifty-six stratigraphic units in the model area were grouped into 25 hydrostratigraphic units based on each unit's propensity toward aquifer or aquitard characteristics. The authors organized the alluvial section into 3 hydrostratigraphic units including 2 aquifers and 1 confining unit. The volcanic units in the model area are organized into 13 hydrostratigraphic units that include 8 aquifers and 5 confining units. The underlying pre-Tertiary rocks are divided into 7 hydrostratigraphic units, including 3 aquifers and 4 confining units. Other units include 1 Tertiary-age sedimentary confining unit and 1 Mesozoic-age granitic confining unit. The model depicts the thickness, extent, and geometric relationships of these hydrostratigraphic units (''layers'' in the model) along with the major structural features (i.e., faults). The model incorporates 178 high-angle normal faults of Tertiary age and 2 low-angle thrust faults of Mesozoic age. The complexity of the model area and the non

  4. EIN Cash Flow Model

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    EIN Cash Flow Model Energy Independence Now (EIN) Objectives Identify financial risks in early hydrogen infrastructure systems and illustrate hydrogen station cash flows under a ...

  5. Analysis and Geochemical Modeling of Vanadium Contamination in Groundwater

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    New Rifle Processing Site, Colorado | Department of Energy and Geochemical Modeling of Vanadium Contamination in Groundwater New Rifle Processing Site, Colorado Analysis and Geochemical Modeling of Vanadium Contamination in Groundwater New Rifle Processing Site, Colorado Analysis and Geochemical Modeling of Vanadium Contamination in Groundwater New Rifle Processing Site, Colorado Analysis and Geochemical Modeling of Vanadium Contamination in Groundwater New Rifle Processing Site, Colorado

  6. A Hydrostratigraphic Framework Model and Alternatives for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Clark, Lincoln and Nye Counties, Nevada

    SciTech Connect (OSTI)

    Bechtel Nevada

    2005-09-01

    A new, revised three-dimensional (3-D) hydrostratigraphic framework model for Frenchman Flat was completed in 2004. The area of interest includes Frenchman Flat, a former nuclear testing area at the Nevada Test Site, and proximal areas. Internal and external reviews of an earlier (Phase I) Frenchman Flat model recommended additional data collection to address uncertainties. Subsequently, additional data were collected for this Phase II initiative, including five new drill holes and a 3-D seismic survey.

  7. Structure and Groundwater Flow in the Espanola Basin Near Rio Grande and Buckman Wellfield

    Broader source: Energy.gov [DOE]

    At the November 12, 2014 Committee meeting Danny Katzman LANL, Provided an Overview of the Groundwater Flow in the Espanola Basin

  8. Numerical investigation for the impact of CO2 geologic sequestration on regional groundwater flow

    SciTech Connect (OSTI)

    Yamamoto, H.; Zhang, K.; Karasaki, K.; Marui, A.; Uehara, H.; Nishikawa, N.

    2009-04-15

    Large-scale storage of carbon dioxide in saline aquifers may cause considerable pressure perturbation and brine migration in deep rock formations, which may have a significant influence on the regional groundwater system. With the help of parallel computing techniques, we conducted a comprehensive, large-scale numerical simulation of CO{sub 2} geologic storage that predicts not only CO{sub 2} migration, but also its impact on regional groundwater flow. As a case study, a hypothetical industrial-scale CO{sub 2} injection in Tokyo Bay, which is surrounded by the most heavily industrialized area in Japan, was considered, and the impact of CO{sub 2} injection on near-surface aquifers was investigated, assuming relatively high seal-layer permeability (higher than 10 microdarcy). A regional hydrogeological model with an area of about 60 km x 70 km around Tokyo Bay was discretized into about 10 million gridblocks. To solve the high-resolution model efficiently, we used a parallelized multiphase flow simulator TOUGH2-MP/ECO2N on a world-class high performance supercomputer in Japan, the Earth Simulator. In this simulation, CO{sub 2} was injected into a storage aquifer at about 1 km depth under Tokyo Bay from 10 wells, at a total rate of 10 million tons/year for 100 years. Through the model, we can examine regional groundwater pressure buildup and groundwater migration to the land surface. The results suggest that even if containment of CO{sub 2} plume is ensured, pressure buildup on the order of a few bars can occur in the shallow confined aquifers over extensive regions, including urban inlands.

  9. The deep hydrogeologic flow system underlying the Oak Ridge Reservation -- Assessing the potential for active groundwater flow and origin of the brine

    SciTech Connect (OSTI)

    Nativ, R.; Halleran, A.; Hunley, A.

    1997-08-01

    The deep hydrogeologic system underlying the Oak Ridge Reservation (ORR) contains contaminants such as radionuclides, heavy metals, nitrates, and organic compounds. The groundwater in the deep system is saline and has been considered to be stagnant in previous studies. This study was designed to address the following questions: is groundwater in the deep system stagnant; is contaminant migration controlled by diffusion only or is advection a viable mechanism; where are the potential outlet points? On the basis of existing and newly collected data, the nature of saline groundwater flow and potential discharge into shallow, freshwater systems was assessed. Data used for this purpose included (1) spatial and temporal pressures and hydraulic heads measured in the deep system, (2) hydraulic parameters of the formations in question, (3) spatial and temporal temperature variations at depth, and (4) spatial and temporal chemical and isotopic composition of the saline groundwater. The observations suggest that the saline water contained at depth is old but not isolated (in terms of recharge and discharge) from the overlying active, freshwater-bearing units. Influx of recent water does occur. Groundwater volumes involved in this flow are likely to be small. The origin of the saline groundwater was assessed by using existing and newly acquired chemical and isotopic data. The proposed model that best fits the data is modification of residual brine from which halite has been precipitated. Other models, such as ultrafiltration and halite dissolution, were also evaluated.

  10. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    SciTech Connect (OSTI)

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-03-01

    Groundwater flow and radionuclide transport at the Shoal underground nuclear test are characterized using three-dimensional numerical models, based on site-specific hydrologic data. The objective of this modeling is to provide the flow and transport models needed to develop a contaminant boundary defining the extent of radionuclide-contaminated groundwater at the site throughout 1,000 years at a prescribed level of confidence. This boundary will then be used to manage the Project Shoal Area for the protection of the public and the environment.

  11. Addendum for the Phase I Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nye County, Nevada, Revision 0 (page changes)

    SciTech Connect (OSTI)

    John McCord

    2007-05-01

    This document, which makes changes to Phase I Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nye County, Nevada, S-N/99205--077, Revision 0 (June 2006), was prepared to address review comments on this final document provided by the Nevada Division of Environmental Protection (NDEP) in a letter dated August 4, 2006. The document includes revised pages that address NDEP review comments and comments from other document users. Change bars are included on these pages to identify where the text was revised. In addition to the revised pages, the following clarifications are made for the two plates inserted in the back of the document: Plate 4: Disregard the repeat of legend text Drill Hole Name and Drill Hole Location in the lower left corner of the map. Plate 6: The symbol at the ER-16-1 location (white dot on the lower left side of the map) is not color-coded because no water level has been determined. The well location is included for reference. Plate 6: The symbol at the ER-12-1 location (upper left corner of the map), a yellow dot, represents the lower water level elevation. The higher water level elevation, represented by a red dot, was overprinted.

  12. Stable isotope and groundwater flow dynamics of agricultural irrigation recharge into groundwater resources of the Central Valley, California

    SciTech Connect (OSTI)

    Davisson, M.L.; Criss, R.E.

    1995-01-01

    Intensive agricultural irrigation and overdraft of groundwater in the Central Valley of California profoundly affect the regional quality and availability of shallow groundwater resources. In the natural state, the {delta}{sup 18}O values of groundwater were relatively homogeneous (mostly -7.0 {+-} 0.5{per_thousand}), reflecting local meteoric recharge that slowly (1-3m/yr) flowed toward the valley axis. Today, on the west side of the valley, the isotope distribution is dominated by high {sup 18}O enclosures formed by recharge of evaporated irrigation waters, while the east side has bands of low {sup 18}O groundwater indicating induced recharge from rivers draining the Sierra Nevada mountains. Changes in {delta}{sup 18}O values caused by the agricultural recharge strongly correlate with elevated nitrate concentrations (5 to >100 mg/L) that form pervasive, non-point source pollutants. Small, west-side cities dependent solely on groundwater resources have experienced increases of >1.0 mg/L per year of nitrate for 10-30 years. The resultant high nitrates threaten the economical use of the groundwater for domestic purposes, and have forced some well shut-downs. Furthermore, since >80% of modern recharge is now derived from agricultural irrigation, and because modern recharge rates are {approximately}10 times those of the natural state, agricultural land retirement by urbanization will severely curtail the current safe-yields and promote overdraft pumping. Such overdrafting has occurred in the Sacramento metropolitan area for {approximately}40 years, creating cones of depression {approximately}25m deep. Today, groundwater withdrawal in Sacramento is approximately matched by infiltration of low {sup 18}O water (-11.0{per_thousand}) away from the Sacramento and American Rivers, which is estimated to occur at 100-300m/year from the sharp {sup 18}O gradients in our groundwater isotope map.

  13. Phase I Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nye County, Nevada, Revision 1

    SciTech Connect (OSTI)

    Nathan Bryant

    2008-05-01

    This document presents a summary and framework of available transport data and other information directly relevant to the development of the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU) 99 groundwater transport model. Where appropriate, data and information documented elsewhere are briefly summarized with reference to the complete documentation.

  14. Evaluation of groundwater flow and transport at the Shoal underground nuclear test: An interim report

    SciTech Connect (OSTI)

    Pohll, G.; Chapman, J.; Hassan, A.; Papelis, C.; Andricevic, R.; Shirley, C.

    1998-07-01

    Since 1962, all United States nuclear tests have been conducted underground. A consequence of this testing has been the deposition of large amounts of radioactive materials in the subsurface, sometimes in direct contact with groundwater. The majority of this testing occurred on the Nevada Test Site, but a limited number of experiments were conducted in other locations. One of these is the subject of this report, the Project Shoal Area (PSA), located about 50 km southeast of Fallon, Nevada. The Shoal test consisted of a 12-kiloton-yield nuclear detonation which occurred on October 26, 1963. Project Shoal was part of studies to enhance seismic detection of underground nuclear tests, in particular, in active earthquake areas. Characterization of groundwater contamination at the Project Shoal Area is being conducted by the US Department of Energy (DOE) under the Federal Facility Agreement and Consent Order (FFACO) with the State of Nevada Department of Environmental Protection and the US Department of Defense (DOD). This order prescribes a Corrective Action Strategy (Appendix VI), which, as applied to underground nuclear tests, involves preparing a Corrective Action Investigation Plan (CAIP), Corrective Action Decision Document (CADD), Corrective Action Plan, and Closure Report. The scope of the CAIP is flow and transport modeling to establish contaminant boundaries that are protective of human health and the environment. This interim report describes the current status of the flow and transport modeling for the PSA.

  15. Phase II Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Nye County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    DeNovio, Nicole M.; Bryant, Nathan; King, Chrissi B.; Bhark, Eric; Drellack, Sigmund L.; Pickens, John F.; Farnham, Irene; Brooks, Keely M.; Reimus, Paul; Aly, Alaa

    2005-04-01

    This report documents pertinent transport data and data analyses as part of the Phase II Corrective Action Investigation (CAI) for Frenchman Flat (FF) Corrective Action Unit (CAU) 98. The purpose of this data compilation and related analyses is to provide the primary reference to support parameterization of the Phase II FF CAU transport model.

  16. Modeling to Support Groundwater Contaminant Boundaries for the Shoal Underground Nuclear Test

    SciTech Connect (OSTI)

    K. Pohlmann; G. Pohll; J. Chapman; A. Hassan; R. Carroll; C. Shirley

    2004-03-01

    The purpose of this work is to characterize groundwater flow and contaminant transport at the Shoal underground nuclear test through numerical modeling using site-specific hydrologic data. The ultimate objective is the development of a contaminant boundary, a model-predicted perimeter defining the extent of radionuclide-contaminated groundwater from the underground test throughout 1,000 years at a prescribed level of confidence. This boundary will be developed using the numerical models described here, after they are approved for that purpose by DOE and NDEP.

  17. Determining flow, recharge, and vadose zonedrainage in anunconfined aquifer from groundwater strontium isotope measurements, PascoBasin, WA

    SciTech Connect (OSTI)

    mjsingleton@lbl.gov

    2004-06-29

    Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near the western margin of the Hanford Site, and ambient drainage may be up to 30 mm/yr in the center of the site assuming an average bulk rock weathering rate of 10-7.5 g/g/yr.

  18. Groundwater flow, late cementation, and petroleum accumulation the Permian Lyons Sandstone, Denver basin

    SciTech Connect (OSTI)

    Lee, M.K.; Bethke, C.M. )

    1994-02-01

    The gray diagenetic facies of the Permian Lyons Sandstone, associated with all known petroleum accumulations in the formation, formed late in the history of the Denver basin as an alteration product of the formation's red facies. The red facies that makes up most of the sandstone contains iron oxide coating, quartz overgrowths and calcite cements. The gray facies, which occurs locally in the deep basin, is distinguished by pore-filling dolomite and anhydrite cements and by a lack of iron oxide and calcite. The dolomite and anhydrite cements overlie bitumen that was deposited by migrating oil, and hence formed after oil was first generated in the basin, late in the Cretaceous or early in the Tertiary. The isotopic composition of oxygen in the dolomite ranges to such light values that the cement must have formed deep in the basin in the presence of meteoric water. The gray facies likely formed in a regime of groundwater flow resulting from Laramide uplift of the Front Range during the Tertiary. In our model, saline groundwater flowed eastward through the Pennsylvanian Fountain Formation and then upwelled along the basin axis, where is discharged into the Lyons Sandstone. The saline water mixed with more dilute groundwater in the Lyons, driving a reaction that dissolved calcite and, by a common-ion effect, precipitated dolomite and anhydrite. The facies' gray color resulted from reduction of ferric oxide in the presence of migrating oil or the Fountain brine. Underlying source beds by this time had begun to generate petroleum, which migrated by buoyancy into the Lyons. The association of the gray facies with petroleum accumulations can be explained if the Fountain brines discharged across aquitards along the same fractures that transmitted oil. As petroleum accumulated in the Lyons, the newly formed cements prevented continued migration, as is observed in shallower strata, by sealing oil into the reservoirs from which it is produced today. 77 refs., 16 figs., 5 tabs.

  19. Site-Scale Saturated Zone Flow Model

    SciTech Connect (OSTI)

    G. Zyvoloski

    2003-12-17

    The purpose of this model report is to document the components of the site-scale saturated-zone flow model at Yucca Mountain, Nevada, in accordance with administrative procedure (AP)-SIII.lOQ, ''Models''. This report provides validation and confidence in the flow model that was developed for site recommendation (SR) and will be used to provide flow fields in support of the Total Systems Performance Assessment (TSPA) for the License Application. The output from this report provides the flow model used in the ''Site-Scale Saturated Zone Transport'', MDL-NBS-HS-000010 Rev 01 (BSC 2003 [162419]). The Site-Scale Saturated Zone Transport model then provides output to the SZ Transport Abstraction Model (BSC 2003 [164870]). In particular, the output from the SZ site-scale flow model is used to simulate the groundwater flow pathways and radionuclide transport to the accessible environment for use in the TSPA calculations. Since the development and calibration of the saturated-zone flow model, more data have been gathered for use in model validation and confidence building, including new water-level data from Nye County wells, single- and multiple-well hydraulic testing data, and new hydrochemistry data. In addition, a new hydrogeologic framework model (HFM), which incorporates Nye County wells lithology, also provides geologic data for corroboration and confidence in the flow model. The intended use of this work is to provide a flow model that generates flow fields to simulate radionuclide transport in saturated porous rock and alluvium under natural or forced gradient flow conditions. The flow model simulations are completed using the three-dimensional (3-D), finite-element, flow, heat, and transport computer code, FEHM Version (V) 2.20 (software tracking number (STN): 10086-2.20-00; LANL 2003 [161725]). Concurrently, process-level transport model and methodology for calculating radionuclide transport in the saturated zone at Yucca Mountain using FEHM V 2.20 are being

  20. Uranium Elemental and Isotopic Constraints on Groundwater Flow Beneath the Nopal I Uranium Deposit, Pena Blanca, Mexico

    SciTech Connect (OSTI)

    S.J. Goldstein; M.T. Murrell; A.M. Simmons

    2005-07-11

    The Nopal I uranium deposit in Chihuahua, Mexico, is an excellent analogue for evaluating the fate of spent fuel, associated actinides, and fission products over long time scales for the proposed Yucca Mountain high-level nuclear waste repository. In 2003, three groundwater wells were drilled directly adjacent to (PB-1) and 50 m on either side of the uranium deposit (PB-2 and PB-3) in order to evaluate uranium-series transport in three dimensions. After drilling, uranium concentrations were elevated in all of the three wells (0.1-18 ppm) due to drilling activities and subsequently decreased to {approx}5-20% of initial values over the next several months. The {sup 234}U/{sup 238}U activity ratios were similar for PB-1 and PB-2 (1.005 to 1.079) but distinct for PB-3 (1.36 to 1.83) over this time period, suggesting limited mixing between groundwater from these wells over these short time and length scales. Regional groundwater wells located up to several km from the deposit also have distinct uranium isotopic characteristics and constrain mixing over larger length and time scales. We model the decreasing uranium concentrations in the newly drilled wells with a simple one-dimensional advection-dispersion model, assuming uranium is introduced as a slug to each of the wells and transported as a conservative tracer. Using this model for our data, the relative uranium concentrations are dependent on both the longitudinal dispersion as well as the mean groundwater flow velocity. These parameters have been found to be correlated in both laboratory and field studies of groundwater velocity and dispersion (Klotz et al., 1980). Using typical relationships between velocity and dispersion for field and laboratory studies along with the relationship observed from our uranium data, both velocity (1-10 n/yr) and dispersion coefficient (1E-5 to 1E-2 cm{sup 2}/s) can be derived from the modeling. As discussed above, these relatively small flow velocities and dispersivities agree with

  1. Review and selection of unsaturated flow models

    SciTech Connect (OSTI)

    Reeves, M.; Baker, N.A.; Duguid, J.O.

    1994-04-04

    Since the 1960`s, ground-water flow models have been used for analysis of water resources problems. In the 1970`s, emphasis began to shift to analysis of waste management problems. This shift in emphasis was largely brought about by site selection activities for geologic repositories for disposal of high-level radioactive wastes. Model development during the 1970`s and well into the 1980`s focused primarily on saturated ground-water flow because geologic repositories in salt, basalt, granite, shale, and tuff were envisioned to be below the water table. Selection of the unsaturated zone at Yucca Mountain, Nevada, for potential disposal of waste began to shift model development toward unsaturated flow models. Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) has the responsibility to review, evaluate, and document existing computer models; to conduct performance assessments; and to develop performance assessment models, where necessary. This document describes the CRWMS M&O approach to model review and evaluation (Chapter 2), and the requirements for unsaturated flow models which are the bases for selection from among the current models (Chapter 3). Chapter 4 identifies existing models, and their characteristics. Through a detailed examination of characteristics, Chapter 5 presents the selection of models for testing. Chapter 6 discusses the testing and verification of selected models. Chapters 7 and 8 give conclusions and make recommendations, respectively. Chapter 9 records the major references for each of the models reviewed. Appendix A, a collection of technical reviews for each model, contains a more complete list of references. Finally, Appendix B characterizes the problems used for model testing.

  2. Recommendations for computer modeling codes to support the UMTRA groundwater restoration project

    SciTech Connect (OSTI)

    Tucker, M.D.; Khan, M.A.

    1996-04-01

    The Uranium Mill Tailings Remediation Action (UMTRA) Project is responsible for the assessment and remedial action at the 24 former uranium mill tailings sites located in the US. The surface restoration phase, which includes containment and stabilization of the abandoned uranium mill tailings piles, has a specific termination date and is nearing completion. Therefore, attention has now turned to the groundwater restoration phase, which began in 1991. Regulated constituents in groundwater whose concentrations or activities exceed maximum contaminant levels (MCLs) or background levels at one or more sites include, but are not limited to, uranium, selenium, arsenic, molybdenum, nitrate, gross alpha, radium-226 and radium-228. The purpose of this report is to recommend computer codes that can be used to assist the UMTRA groundwater restoration effort. The report includes a survey of applicable codes in each of the following areas: (1) groundwater flow and contaminant transport modeling codes, (2) hydrogeochemical modeling codes, (3) pump and treat optimization codes, and (4) decision support tools. Following the survey of the applicable codes, specific codes that can best meet the needs of the UMTRA groundwater restoration program in each of the four areas are recommended.

  3. Three-Dimensional Groundwater Models of the 300 Area at the Hanford Site, Washington State

    SciTech Connect (OSTI)

    Williams, Mark D.; Rockhold, Mark L.; Thorne, Paul D.; Chen, Yousu

    2008-09-01

    Researchers at Pacific Northwest National Laboratory developed field-scale groundwater flow and transport simulations of the 300 Area to support the 300-FF-5 Operable Unit Phase III Feasibility Study. The 300 Area is located in the southeast portion of the U.S. Department of Energy’s Hanford Site in Washington State. Historical operations involving uranium fuel fabrication and research activities at the 300 Area have contaminated engineered liquid-waste disposal facilities, the underlying vadose zone, and the uppermost aquifer with uranium. The main objectives of this research were to develop numerical groundwater flow and transport models to help refine the site conceptual model, and to assist assessment of proposed alternative remediation technologies focused on the 300 Area uranium plume.

  4. Supplement to a hydrologic framework for the Oak Ridge Reservation, Oak Ridge, Tennessee. Summary of groundwater modeling

    SciTech Connect (OSTI)

    Moore, G.K.; Toran, L.E.

    1992-11-01

    The information in this report should prove useful for flow and contaminant-transport modeling of groundwater and for evaluating the alternatives for remedial action. New data on porosity and permeability have been analyzed and interpreted to produce a better understanding of the relationships between unfractured rock, low permeability intervals, and relatively permeable intervals. Specifically, the dimensions, orientations, depths, and spacings of pervious fractures have been measured or calculated; the depths and directions of subsurface flow paths (Solomon et al. 1992, pp. 3--21 to 3--23) have been corroborated with new data; fractures near the water table have been shown to have different characteristics than those at deeper levels; and the relationships between groundwater flows in fractures and flows in the continuum have been described. This is the information needed for the numerical modeling of groundwater flows. Other information in this report should result in a better understanding of spatial and temporal differences in water chemistry, including changes in contaminant concentrations. Temporal changes in groundwater chemistry have been shown to occur mostly near the water table. These changes consist of a periodic dilution of chemical constituents by recharge and a slow increase in constituent concentrations between recharge events. At discharge locations, spatial differences in groundwater chemistry are integrated by mixing. The monitoring of water chemistry in streams near contaminant sources may produce a better indication of contaminant releases and trends than do the records obtained from a few upgradient and downgradient wells.

  5. UZ Flow Models and Submodels

    SciTech Connect (OSTI)

    Y. Wu

    2004-11-01

    The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.

  6. Updated Conceptual Model for the 300 Area Uranium Groundwater Plume

    SciTech Connect (OSTI)

    Zachara, John M.; Freshley, Mark D.; Last, George V.; Peterson, Robert E.; Bjornstad, Bruce N.

    2012-11-01

    The 300 Area uranium groundwater plume in the 300-FF-5 Operable Unit is residual from past discharge of nuclear fuel fabrication wastes to a number of liquid (and solid) disposal sites. The source zones in the disposal sites were remediated by excavation and backfilled to grade, but sorbed uranium remains in deeper, unexcavated vadose zone sediments. In spite of source term removal, the groundwater plume has shown remarkable persistence, with concentrations exceeding the drinking water standard over an area of approximately 1 km2. The plume resides within a coupled vadose zone, groundwater, river zone system of immense complexity and scale. Interactions between geologic structure, the hydrologic system driven by the Columbia River, groundwater-river exchange points, and the geochemistry of uranium contribute to persistence of the plume. The U.S. Department of Energy (DOE) recently completed a Remedial Investigation/Feasibility Study (RI/FS) to document characterization of the 300 Area uranium plume and plan for beginning to implement proposed remedial actions. As part of the RI/FS document, a conceptual model was developed that integrates knowledge of the hydrogeologic and geochemical properties of the 300 Area and controlling processes to yield an understanding of how the system behaves and the variables that control it. Recent results from the Hanford Integrated Field Research Challenge site and the Subsurface Biogeochemistry Scientific Focus Area Project funded by the DOE Office of Science were used to update the conceptual model and provide an assessment of key factors controlling plume persistence.

  7. Reduced order models for prediction of groundwater quality impacts from CO₂ and brine leakage

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zheng, Liange; Carroll, Susan; Bianchi, Marco; Mansoor, Kayyum; Sun, Yunwei; Birkholzer, Jens

    2014-12-31

    A careful assessment of the risk associated with geologic CO₂ storage is critical to the deployment of large-scale storage projects. A potential risk is the deterioration of groundwater quality caused by the leakage of CO₂ and brine leakage from deep subsurface reservoirs. In probabilistic risk assessment studies, numerical modeling is the primary tool employed to assess risk. However, the application of traditional numerical models to fully evaluate the impact of CO₂ leakage on groundwater can be computationally complex, demanding large processing times and resources, and involving large uncertainties. As an alternative, reduced order models (ROMs) can be used as highlymore » efficient surrogates for the complex process-based numerical models. In this study, we represent the complex hydrogeological and geochemical conditions in a heterogeneous aquifer and subsequent risk by developing and using two separate ROMs. The first ROM is derived from a model that accounts for the heterogeneous flow and transport conditions in the presence of complex leakage functions for CO₂ and brine. The second ROM is obtained from models that feature similar, but simplified flow and transport conditions, and allow for a more complex representation of all relevant geochemical reactions. To quantify possible impacts to groundwater aquifers, the basic risk metric is taken as the aquifer volume in which the water quality of the aquifer may be affected by an underlying CO₂ storage project. The integration of the two ROMs provides an estimate of the impacted aquifer volume taking into account uncertainties in flow, transport and chemical conditions. These two ROMs can be linked in a comprehensive system level model for quantitative risk assessment of the deep storage reservoir, wellbore leakage, and shallow aquifer impacts to assess the collective risk of CO₂ storage projects.« less

  8. Reduced order models for prediction of groundwater quality impacts from CO? and brine leakage

    SciTech Connect (OSTI)

    Zheng, Liange; Carroll, Susan; Bianchi, Marco; Mansoor, Kayyum; Sun, Yunwei; Birkholzer, Jens

    2014-12-31

    A careful assessment of the risk associated with geologic CO? storage is critical to the deployment of large-scale storage projects. A potential risk is the deterioration of groundwater quality caused by the leakage of CO? and brine leakage from deep subsurface reservoirs. In probabilistic risk assessment studies, numerical modeling is the primary tool employed to assess risk. However, the application of traditional numerical models to fully evaluate the impact of CO? leakage on groundwater can be computationally complex, demanding large processing times and resources, and involving large uncertainties. As an alternative, reduced order models (ROMs) can be used as highly efficient surrogates for the complex process-based numerical models. In this study, we represent the complex hydrogeological and geochemical conditions in a heterogeneous aquifer and subsequent risk by developing and using two separate ROMs. The first ROM is derived from a model that accounts for the heterogeneous flow and transport conditions in the presence of complex leakage functions for CO? and brine. The second ROM is obtained from models that feature similar, but simplified flow and transport conditions, and allow for a more complex representation of all relevant geochemical reactions. To quantify possible impacts to groundwater aquifers, the basic risk metric is taken as the aquifer volume in which the water quality of the aquifer may be affected by an underlying CO? storage project. The integration of the two ROMs provides an estimate of the impacted aquifer volume taking into account uncertainties in flow, transport and chemical conditions. These two ROMs can be linked in a comprehensive system level model for quantitative risk assessment of the deep storage reservoir, wellbore leakage, and shallow aquifer impacts to assess the collective risk of CO? storage projects.

  9. DOEINVIl0845-51 DC-703 GROUNDWATER FLOW NEAR THE SHOAL SITE,

    Office of Legacy Management (LM)

    DOEINVIl0845-51 DC-703 GROUNDWATER FLOW NEAR THE SHOAL SITE, SAND SPRINGS RANGE, NEVADA: IMPACT OF DENSITY-DRIVEN FLOW Prepared by Jenny Chapman, Todd Mihevc, and Alan McKay Submitted to Nevada Operations Office U.S. Department of Energy Las Vegas, Nevada September 1994 Publication #45130 This report was prepared as an account of work sponsored by the United States Government Neither the United States nor the United States Department of Energy, nor any of their employees, makes any warranty,

  10. Unsaturated Groundwater and Heat Transport Model.

    Energy Science and Technology Software Center (OSTI)

    2002-05-13

    TMVOC is a simulator for multicomponent, multiphase, nonisothermal flows of water, soil gas, and several volatile organic chemicals (VOCs). It is based on the M2NOTS-code developed by Adeyinka Adenekan as part of his PhD project at UC Berkeley (Adenekan, 1992). TMVOC is written in standard FORTRAN 77 and operates within the framework of TOUGH2, Version 2.0 (T2V2; Pruess et al., 1999). The code consists of two modules (groups of routines) named *t2fm.f* and *emvoc.f* thatmore » must be linked to several standard T2V2 modules.« less

  11. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico

    SciTech Connect (OSTI)

    Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A. J.

    2009-10-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ({approx}10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that {sup 230}Th/{sup 238}U activity ratios range from 0.005-0.48 and {sup 226}Ra/{sup 238}U activity ratios range from 0.006-113. {sup 239}Pu/{sup 238}U mass ratios for the saturated zone are <2 x 10{sup -14}, and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order {sup 238}U{approx}{sup 226}Ra > {sup 230}Th{approx}{sup 239}Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  12. Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California

    SciTech Connect (OSTI)

    D`Agnese, F.A.; Faunt, C.C.; Turner, A.K.; Hill, M.C.

    1997-12-31

    Yucca Mountain is being studied as a potential site for a high-level radioactive waste repository. In cooperation with the U.S. Department of Energy, the U.S. Geological Survey is evaluating the geologic and hydrologic characteristics of the ground-water system. The study area covers approximately 100,000 square kilometers between lat 35{degrees}N., long 115{degrees}W and lat 38{degrees}N., long 118{degrees}W and encompasses the Death Valley regional ground-water flow system. Hydrology in the region is a result of both the and climatic conditions and the complex described as dominated by interbasinal flow and may be conceptualized as having two main components: a series of relatively shallow and localized flow paths that are superimposed on deeper regional flow paths. A significant component of the regional ground-water flow is through a thick Paleozoic carbonate rock sequence. Throughout the regional flow system, ground-water flow is probably controlled by extensive and prevalent structural features that result from regional faulting and fracturing. Hydrogeologic investigations over a large and hydrogeologically complex area impose severe demands on data management. This study utilized geographic information systems and geoscientific information systems to develop, store, manipulate, and analyze regional hydrogeologic data sets describing various components of the ground-water flow system.

  13. Groundwater Flow Systems at the Nevada Test Site, Nevada: A Synthesis of Potentiometric Contours, Hydrostratigraphy, and Geologic Structures

    SciTech Connect (OSTI)

    Fenelon, Joseph M.; Sweetkind, Donald S.; Laczniak, Randell J.

    2010-01-25

    Contaminants introduced into the subsurface of the Nevada Test Site by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. The potential for contaminant movement away from the underground test areas and into the accessible environment is greatest by groundwater transport. The primary hydrologic control on this transport is evaluated and examined through a series of contour maps developed to represent the hydraulic-head distribution within each of the major aquifers underlying the area. Aquifers were identified and their extents delineated by merging and analyzing multiple hydrostratigraphic framework models developed by other investigators from existing geologic information. A map of the hydraulic-head distribution in each major aquifer was developed from a detailed evaluation and assessment of available water-level measurements. Multiple spreadsheets that accompany this report provide pertinent water-level and geologic data by well or drill hole. Aquifers are mapped and discussed in general terms as being one of two types: alluvial-volcanic, or carbonate. Both aquifer types are subdivided and mapped as independent regional and local aquifers, based on the continuity of their component rock. Groundwater-flow directions, approximated from potentiometric contours that were developed from the hydraulic-head distribution, are indicated on the maps and discussed for each of the regional aquifers and for selected local aquifers. Hydraulic heads vary across the study area and are interpreted to range in altitude from greater than 5,000 feet in a regional alluvial-volcanic aquifer beneath a recharge area in the northern part of the study area to less than 2,300 feet in regional alluvial-volcanic and carbonate aquifers in the southwestern part of the study area. Flow directions throughout the study area are dominantly south-southwest with some local deviations. Vertical hydraulic

  14. Grand challenge problems in environmental modeling and remediation: Groundwater contaminant transport. Final project report 1998

    SciTech Connect (OSTI)

    1998-04-01

    The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997.

  15. Groundwater Model Validation for the Project Shoal Area, Corrective Action Unit 447

    SciTech Connect (OSTI)

    2008-05-19

    Stoller has examined newly collected water level data in multiple wells at the Shoal site. On the basis of these data and information presented in the report, we are currently unable to confirm that the model is successfully validated. Most of our concerns regarding the model stem from two findings: (1) measured water level data do not provide clear evidence of a prevailing lateral flow direction; and (2) the groundwater flow system has been and continues to be in a transient state, which contrasts with assumed steady-state conditions in the model. The results of DRI's model validation efforts and observations made regarding water level behavior are discussed in the following sections. A summary of our conclusions and recommendations for a path forward are also provided in this letter report.

  16. An Update of the Analytical Groundwater Modeling to Assess Water Resource Impacts at the Afton Solar Energy Zone

    SciTech Connect (OSTI)

    Quinn, John J.; Greer, Christopher B.; Carr, Adrianne E.

    2014-10-01

    The purpose of this study is to update a one-dimensional analytical groundwater flow model to examine the influence of potential groundwater withdrawal in support of utility-scale solar energy development at the Afton Solar Energy Zone (SEZ) as a part of the Bureau of Land Management’s (BLM’s) Solar Energy Program. This report describes the modeling for assessing the drawdown associated with SEZ groundwater pumping rates for a 20-year duration considering three categories of water demand (high, medium, and low) based on technology-specific considerations. The 2012 modeling effort published in the Final Programmatic Environmental Impact Statement for Solar Energy Development in Six Southwestern States (Solar PEIS; BLM and DOE 2012) has been refined based on additional information described below in an expanded hydrogeologic discussion.

  17. Groundwater Data Package for the 2004 Composite Analysis

    SciTech Connect (OSTI)

    Thorne, Paul D.

    2004-08-11

    This report presents data and information that supports the groundwater module. The conceptual model of groundwater flow and transport at the Hanford Site is described and specific information applied in the numerical implementation module is provided.

  18. Modeling uranium transport in acidic contaminated groundwater with base addition

    SciTech Connect (OSTI)

    Zhang, Fan; Luo, Wensui; Parker, Jack C.; Brooks, Scott C; Watson, David B; Jardine, Philip; Gu, Baohua

    2011-01-01

    This study investigates reactive transport modeling in a column of uranium(VI)-contaminated sediments with base additions in the circulating influent. The groundwater and sediment exhibit oxic conditions with low pH, high concentrations of NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, U and various metal cations. Preliminary batch experiments indicate that additions of strong base induce rapid immobilization of U for this material. In the column experiment that is the focus of the present study, effluent groundwater was titrated with NaOH solution in an inflow reservoir before reinjection to gradually increase the solution pH in the column. An equilibrium hydrolysis, precipitation and ion exchange reaction model developed through simulation of the preliminary batch titration experiments predicted faster reduction of aqueous Al than observed in the column experiment. The model was therefore modified to consider reaction kinetics for the precipitation and dissolution processes which are the major mechanism for Al immobilization. The combined kinetic and equilibrium reaction model adequately described variations in pH, aqueous concentrations of metal cations (Al, Ca, Mg, Sr, Mn, Ni, Co), sulfate and U(VI). The experimental and modeling results indicate that U(VI) can be effectively sequestered with controlled base addition due to sorption by slowly precipitated Al with pH-dependent surface charge. The model may prove useful to predict field-scale U(VI) sequestration and remediation effectiveness.

  19. URANIUM-SERIES CONSTRAINTS ON RADIONUCLIDE TRANSPORT AND GROUNDWATER FLOW AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, MEXICO

    SciTech Connect (OSTI)

    S. J. Goldstein, S. Luo, T. L. Ku, and M. T. Murrell

    2006-04-01

    Uranium-series data for groundwater samples from the vicinity of the Nopal I uranium ore deposit are used to place constraints on radionuclide transport and hydrologic processes at this site, and also, by analogy, at Yucca Mountain. Decreasing uranium concentrations for wells drilled in 2003 suggest that groundwater flow rates are low (< 10 m/yr). Field tests, well productivity, and uranium isotopic constraints also suggest that groundwater flow and mixing is limited at this site. The uranium isotopic systematics for water collected in the mine adit are consistent with longer rock-water interaction times and higher uranium dissolution rates at the front of the adit where the deposit is located. Short-lived nuclide data for groundwater wells are used to calculate retardation factors that are on the order of 1,000 for radium and 10,000 to 10,000,000 for lead and polonium. Radium has enhanced mobility in adit water and fractures near the deposit.

  20. Analysis of Aquifer Response, Groundwater Flow, and PlumeEvolution at Site OU 1, Former Fort Ord, California

    SciTech Connect (OSTI)

    Jordan, Preston D.; Oldenburg, Curtis M.; Su, Grace W.

    2005-02-24

    This report presents a continuation from Oldenburg et al. (2002) of analysis of the hydrogeology, In-Situ Permeable Flow Sensor (ISPFS) results, aquifer response, and changes in the trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County. Fuels and solvents were burned on a portion of OU 1 called the Fire Drill Area (FDA) during airport fire suppression training between 1962 and 1985. This activity resulted in soil and groundwater contamination in the unconfined A-aquifer. In the late 1980's, soil excavation and bioremediation were successful in remediating soil contamination at the site. Shortly thereafter, a groundwater pump, treat, and recharge system commenced operation. This system has been largely successful at remediating groundwater contamination at the head of the groundwater plume. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In the analyses presented here, we augment our prior work (Oldenburg et al., 2002) with new information including treatment-system totalizer data, recent water-level and chemistry data, and data collected from new wells to discern trends in contaminant migration and groundwater flow that may be useful for ongoing remediation efforts. Some conclusions from the prior study have been modified based on these new analyses, and these are pointed out clearly in this report.

  1. Characterization of Flow Paths, Residence Time and Media Chemistry in Complex Landscapes to Integrate Surface, Groundwater and Stream Processes and Inform Models of Hydrologic and Water Quality Response to Land Use Activities; Savannah River Site

    SciTech Connect (OSTI)

    Bitew, Menberu; Jackson, Rhett

    2015-02-01

    The objective of this report is to document the methodology used to calculate the three hydro-geomorphic indices: C Index, Nhot spot, and Interflow Contributing Area (IFC Area). These indices were applied in the Upper Four Mile Creek Watershed in order to better understand the potential mechanisms controlling retention time, path lengths, and potential for nutrient and solute metabolism and exchange associated with the geomorphic configurations of the upland contributing areas, groundwater, the riparian zone, and stream channels.

  2. Groundwater Screen

    Energy Science and Technology Software Center (OSTI)

    1993-11-09

    GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non radioactive substances from surface or buried sources and release to percolation ponds. The code calculates the limiting soil concentration or effluent release concentration such that, after leaching and transport to the aquifer, regulatory contaminant levels in groundwater are not exceeded. The code uses a mass conservation approach to model three processes: Contaminant release from a source volume, contaminant transport inmore » the unsaturated zone, and contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. Transport in the unsaturated zone is described by a plug flow model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation in groundwater. Concentration as a function of time at a user specified receptor point and maximum concentration averaged over the exposure interval are also calculated. In addition, the code calculates transport and impacts of radioactive progeny. Input to GWSCREEN is through one, free format ASCII file. This code was designed for assessment and screening of the groundwater pathway when field data is limited. It was not intended to be a predictive tool.« less

  3. Modeling Fluid Flow in Natural Systems, Model Validation and...

    Energy Savers [EERE]

    Modeling Fluid Flow in Natural Systems, Model Validation and Demonstration Modeling Fluid Flow in Natural Systems, Model Validation and Demonstration Clay and granitic units are ...

  4. Transient Inverse Calibration of Site-Wide Groundwater Model to Hanford Operational Impacts from 1943 to 1996--Alternative Conceptual Model Considering Interaction with Uppermost Basalt Confined Aquifer

    SciTech Connect (OSTI)

    Vermeul, Vincent R.; Cole, Charles R.; Bergeron, Marcel P.; Thorne, Paul D.; Wurstner, Signe K.

    2001-08-29

    The baseline three-dimensional transient inverse model for the estimation of site-wide scale flow parameters, including their uncertainties, using data on the transient behavior of the unconfined aquifer system over the entire historical period of Hanford operations, has been modified to account for the effects of basalt intercommunication between the Hanford unconfined aquifer and the underlying upper basalt confined aquifer. Both the baseline and alternative conceptual models (ACM-1) considered only the groundwater flow component and corresponding observational data in the 3-Dl transient inverse calibration efforts. Subsequent efforts will examine both groundwater flow and transport. Comparisons of goodness of fit measures and parameter estimation results for the ACM-1 transient inverse calibrated model with those from previous site-wide groundwater modeling efforts illustrate that the new 3-D transient inverse model approach will strengthen the technical defensibility of the final model(s) and provide the ability to incorporate uncertainty in predictions related to both conceptual model and parameter uncertainty. These results, however, indicate that additional improvements are required to the conceptual model framework. An investigation was initiated at the end of this basalt inverse modeling effort to determine whether facies-based zonation would improve specific yield parameter estimation results (ACM-2). A description of the justification and methodology to develop this zonation is discussed.

  5. Groundwater Monitoring

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater Monitoring Groundwater Monitoring LANL maintains an extensive groundwater monitoring and surveillance program through sampling. August 1, 2013 Conceptual model of water movement and geology at Los Alamos National Laboratory Conceptual model of water movement and geology at Los Alamos National Laboratory RELATED IMAGES http://farm4.staticflickr.com/3749/9827580556_473a91fd78_t.jpg Enlarge

  6. Evapotranspiration Within the Groundwater Model Domain of the Tuba City, Arizona, Disposal Site Interim Report

    SciTech Connect (OSTI)

    None, None

    2015-03-01

    The revised groundwater model includes estimates of evapotranspiration (ET). The types of vegetation and the influences of ET on groundwater hydrology vary within the model domain. Some plant species within the model domain, classified as phreatophytes, survive by extracting groundwater. ET within these plant communities can result in a net discharge of groundwater if ET exceeds precipitation. Other upland desert plants within the model domain survive on meteoric water, potentially limiting groundwater recharge if ET is equivalent to precipitation. For all plant communities within the model domain, excessive livestock grazing or other disturbances can tip the balance to a net groundwater recharge. This task characterized and mapped vegetation within the groundwater model domain at the Tuba City, Arizona, Site, and then applied a remote sensing algorithm to estimate ET for each vegetation type. The task was designed to address five objectives: 1. Characterize and delineate different vegetation or ET zones within the groundwater model domain, focusing on the separation of plant communities with phreatophytes that survive by tapping groundwater and upland plant communities that are dependent on precipitation. 2. Refine a remote sensing method, developed to estimate ET at the Monument Valley site, for application at the Tuba City site. 3. Estimate recent seasonal and annual ET for all vegetation zones, separating phreatophytic and upland plant communities within the Tuba City groundwater model domain. 4. For selected vegetation zones, estimate ET that might be achieved given a scenario of limited livestock grazing. 5. Analyze uncertainty of ET estimates for each vegetation zone and for the entire groundwater model domain.

  7. Transient Inverse Calibration of Hanford Site-Wide Groundwater Model to Hanford Operational Impacts - 1943 to 1996

    SciTech Connect (OSTI)

    Cole, Charles R.; Bergeron, Marcel P.; Wurstner, Signe K.; Thorne, Paul D.; Orr, Samuel; Mckinley, Mathew I.

    2001-05-31

    This report describes a new initiative to strengthen the technical defensibility of predictions made with the Hanford site-wide groundwater flow and transport model. The focus is on characterizing major uncertainties in the current model. PNNL will develop and implement a calibration approach and methodology that can be used to evaluate alternative conceptual models of the Hanford aquifer system. The calibration process will involve a three-dimensional transient inverse calibration of each numerical model to historical observations of hydraulic and water quality impacts to the unconfined aquifer system from Hanford operations since the mid-1940s.

  8. Modeling shrouded stator cavity flows in axial-flow compressors

    SciTech Connect (OSTI)

    Wellborn, S.R.; Tolchinsky, I.; Okiishi, T.H.

    2000-01-01

    Experiments and computational analyses were completed to understand the nature of shrouded stator cavity flows. From this understanding, a one-dimensional model of the flow through shrouded stator cavities was developed. This model estimates the leakage mass flow, temperature rise, and angular momentum increase through the cavity, given geometry parameters and the flow conditions at the interface between the cavity and primary flow path. This cavity model consists of two components, one that estimates the flow characteristics through the labyrinth seals and the other that predicts the transfer of momentum due to windage. A description of the one-dimensional model is given. The incorporation and use of the one-dimensional model in a multistage compressor primary flow analysis tool is described. The combination of this model and the primary flow solver was used to reliably simulate the significant impact on performance of the increase of hub seal leakage in a twelve-stage axial-flow compressor. Observed higher temperatures of the hub region fluid, different stage matching, and lower overall efficiencies and core flow than expected could be correctly linked to increased hub seal clearance with this new technique. The importance of including these leakage flows in compressor simulations is shown.

  9. Maximum likelihood Bayesian model averaging and its predictive analysis for groundwater reactive transport models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lu, Dan; Ye, Ming; Curtis, Gary P.

    2015-08-01

    While Bayesian model averaging (BMA) has been widely used in groundwater modeling, it is infrequently applied to groundwater reactive transport modeling because of multiple sources of uncertainty in the coupled hydrogeochemical processes and because of the long execution time of each model run. To resolve these problems, this study analyzed different levels of uncertainty in a hierarchical way, and used the maximum likelihood version of BMA, i.e., MLBMA, to improve the computational efficiency. Our study demonstrates the applicability of MLBMA to groundwater reactive transport modeling in a synthetic case in which twenty-seven reactive transport models were designed to predict themore » reactive transport of hexavalent uranium (U(VI)) based on observations at a former uranium mill site near Naturita, CO. Moreover, these reactive transport models contain three uncertain model components, i.e., parameterization of hydraulic conductivity, configuration of model boundary, and surface complexation reactions that simulate U(VI) adsorption. These uncertain model components were aggregated into the alternative models by integrating a hierarchical structure into MLBMA. The modeling results of the individual models and MLBMA were analyzed to investigate their predictive performance. The predictive logscore results show that MLBMA generally outperforms the best model, suggesting that using MLBMA is a sound strategy to achieve more robust model predictions relative to a single model. MLBMA works best when the alternative models are structurally distinct and have diverse model predictions. When correlation in model structure exists, two strategies were used to improve predictive performance by retaining structurally distinct models or assigning smaller prior model probabilities to correlated models. Since the synthetic models were designed using data from the Naturita site, the results of this study are expected to provide guidance for real-world modeling. Finally

  10. Maximum likelihood Bayesian model averaging and its predictive analysis for groundwater reactive transport models

    SciTech Connect (OSTI)

    Lu, Dan; Ye, Ming; Curtis, Gary P.

    2015-08-01

    While Bayesian model averaging (BMA) has been widely used in groundwater modeling, it is infrequently applied to groundwater reactive transport modeling because of multiple sources of uncertainty in the coupled hydrogeochemical processes and because of the long execution time of each model run. To resolve these problems, this study analyzed different levels of uncertainty in a hierarchical way, and used the maximum likelihood version of BMA, i.e., MLBMA, to improve the computational efficiency. Our study demonstrates the applicability of MLBMA to groundwater reactive transport modeling in a synthetic case in which twenty-seven reactive transport models were designed to predict the reactive transport of hexavalent uranium (U(VI)) based on observations at a former uranium mill site near Naturita, CO. Moreover, these reactive transport models contain three uncertain model components, i.e., parameterization of hydraulic conductivity, configuration of model boundary, and surface complexation reactions that simulate U(VI) adsorption. These uncertain model components were aggregated into the alternative models by integrating a hierarchical structure into MLBMA. The modeling results of the individual models and MLBMA were analyzed to investigate their predictive performance. The predictive logscore results show that MLBMA generally outperforms the best model, suggesting that using MLBMA is a sound strategy to achieve more robust model predictions relative to a single model. MLBMA works best when the alternative models are structurally distinct and have diverse model predictions. When correlation in model structure exists, two strategies were used to improve predictive performance by retaining structurally distinct models or assigning smaller prior model probabilities to correlated models. Since the synthetic models were designed using data from the Naturita site, the results of this study are expected to provide guidance for real-world modeling. Finally, limitations of

  11. Stochastic models for turbulent reacting flows

    SciTech Connect (OSTI)

    Kerstein, A.

    1993-12-01

    The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

  12. Ground-water flow and ground- and surface-water interaction at the Weldon Spring quarry, St. Charles County, Missouri

    SciTech Connect (OSTI)

    Imes, J.L.; Kleeschulte, M.J.

    1997-12-31

    Ground-water-level measurements to support remedial actions were made in 37 piezometers and 19 monitoring wells during a 19-month period to assess the potential for ground-water flow from an abandoned quarry to the nearby St. Charles County well field, which withdraws water from the base of the alluvial aquifer. From 1957 to 1966, low-level radioactive waste products from the Weldon Spring chemical plant were placed in the quarry a few hundred feet north of the Missouri River alluvial plain. Uranium-based contaminants subsequently were detected in alluvial ground water south of the quarry. During all but flood conditions, lateral ground-water flow in the bedrock from the quarry, as interpreted from water-table maps, generally is southwest toward Little Femme Osage Creek or south into the alluvial aquifer. After entering the alluvial aquifer, the ground water flows southeast to east toward a ground-water depression presumably produced by pumping at the St. Charles County well field. The depression position varies depending on the Missouri River stage and probably the number and location of active wells in the St. Charles County well field.

  13. Summary of hydrogeologic controls on ground-water flow at the Nevada Test Site, Nye County, Nevada

    SciTech Connect (OSTI)

    Laczniak, R.J.; Cole, J.C.; Sawyer, D.A.; Trudeau, D.A.

    1996-07-01

    The underground testing of nuclear devices has generated substantial volumes of radioactive and other chemical contaminants below ground at the Nevada Test Site (NTS). Many of the more radioactive contaminants are highly toxic and are known to persist in the environment for thousands of years. In response to concerns about potential health hazards, the US Department of Energy, under its Environmental Restoration Program, has made NTS the subject of a long-term investigation. Efforts will assess whether byproducts of underground testing pose a potential hazard to the health and safety of the public and, if necessary, will evaluate and implement steps to remediate any of the identified dangers. Ground-water flow is the primary mechanism by which contaminants can be transported significant distances away from the initial point of injection. Flow paths between contaminant sources and potential receptors are separated by remote areas that span tens of miles. The diversity and structural complexity of the rocks along these flow paths complicates the hydrology of the region. Although the hydrology has been studied in some detail, much still remains uncertain about flow rates and directions through the fractured-rock aquifers that transmit water great distances across this arid region. Unique to the hydrology of NTS are the effects of underground testing, which severely alter local rock characteristics and affect hydrologic conditions throughout the region. This report summarizes what is known and inferred about ground-water flow throughout the NTS region. The report identifies and updates what is known about some of the major controls on ground-water flow, highlights some of the uncertainties in the current understanding, and prioritizes some of the technical needs as related to the Environmental Restoration Program. 113 refs.

  14. Phase I Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nye County, Nevada, Revision 0

    SciTech Connect (OSTI)

    John McCord

    2007-09-01

    This report documents transport data and data analyses for Yucca Flat/Climax Mine CAU 97. The purpose of the data compilation and related analyses is to provide the primary reference to support parameterization of the Yucca Flat/Climax Mine CAU transport model. Specific task objectives were as follows: • Identify and compile currently available transport parameter data and supporting information that may be relevant to the Yucca Flat/Climax Mine CAU. • Assess the level of quality of the data and associated documentation. • Analyze the data to derive expected values and estimates of the associated uncertainty and variability. The scope of this document includes the compilation and assessment of data and information relevant to transport parameters for the Yucca Flat/Climax Mine CAU subsurface within the context of unclassified source-term contamination. Data types of interest include mineralogy, aqueous chemistry, matrix and effective porosity, dispersivity, matrix diffusion, matrix and fracture sorption, and colloid-facilitated transport parameters.

  15. Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex

    SciTech Connect (OSTI)

    Serne, R. Jeffrey; Bjornstad, Bruce N.; Keller, Jason M.; Thorne, Paul D.; Lanigan, David C.; Christensen, J. N.; Thomas, Gregory S.

    2010-07-01

    The B-Complex contains 3 major crib and trench disposal sites and 3 SST farms that have released nearly 346 mega-liters of waste liquids containing the following high groundwater risk drivers: ~14,000 kg of CN, 29,000 kg of Cr, 12,000 kg of U and 145 Ci of Tc-99. After a thorough review of available vadose zone sediment and pore water, groundwater plume, field gamma logging, field electrical resistivity studies, we developed conceptual models for which facilities have been the significant sources of the contaminants in the groundwater and estimated the masses of these contaminants remaining in the vadose zone and currently present in the groundwater in comparison to the totals released. This allowed us to make mass balance calculations on how consistent our knowledge is on the current deep vadose zone and groundwater distribution of contaminants. Strengths and weaknesses of the conceptual models are discussed as well as implications on future groundwater and deep vadose zone remediation alternatives. Our hypothesized conceptual models attribute the source of all of the cyanide and most of the Tc-99 currently in the groundwater to the BY cribs. The source of the uranium is the BX-102 tank overfill event and the source of most of the chromium is the B-7-A&B and B-8 cribs. Our mass balance estimates suggest that there are much larger masses of U, CN, and Tc remaining in the deep vadose zone within ~20 ft of the water table than is currently in the groundwater plumes below the B-Complex. This hypothesis needs to be carefully considered before future remediation efforts are chosen. The masses of these groundwater risk drivers in the the groundwater plumes have been increasing over the last decade and the groundwater plumes are migrating to the northwest towards the Gable Gap. The groundwater flow rate appears to flucuate in response to seasonal changes in hydraulic gradient. The flux of contaminants out of the deep vadose zone from the three proposed sources also

  16. A modeling study of irrigation effects on global surface water and groundwater resources under a changing climate

    SciTech Connect (OSTI)

    Leng, Guoyong; Huang, Maoyi; Tang, Qiuhong; Leung, Lai-Yung R.

    2015-08-25

    In this paper, the effects of irrigation on global surface water (SW) and groundwater (GW) resources are investigated by performing simulations using Community Land Model 4.0 (CLM4) at 0.5-degree resolution driven by downscaled/bias-corrected historical simulations and future projections from five General Circulation Models (GCMs) for 1950-2099. For each climate scenario, three sets of numerical experiments were configured: (1) a control experiment (CTRL) in which all crops are assumed to be rainfed; (2) an irrigation experiment (IRRIG) in which the irrigation module using only SW for irrigation is activated; and (3) a groundwater pumping experiment (PUMP) in which a groundwater pumping scheme coupled with the irrigation module is activated for conjunctive use of SW and GW for irrigation. The parameters associated with irrigation and groundwater pumping are calibrated based on a global inventory of census-based SW and GW use compiled by the Food and Agricultural Organization (FAO). Our results suggest that irrigation could lead to two major opposing effects: SW depletion/GW accumulation in regions with irrigation primarily fed by SW, and SW accumulation/GW depletion in regions with irrigation fed primarily by GW. Furthermore, irrigation depending primarily on SW tends to have larger impacts on low-flow than high-flow conditions, suggesting the potential to increase vulnerability to drought. By the end of the 21st century (2070-2099), climate change significantly increases (relative to 1971-2000) irrigation water demand across the world. Combined with the increased temporal-spatial variability of water supply, this may lead to severe issues of local water scarcity for irrigation. Regionally, irrigation has the potential to aggravate/alleviate climate-induced changes of SW/GW although such effects are negligible when averaged globally. Our results emphasize the importance of accounting for irrigation effects and irrigation sources in regional climate change impact

  17. A modeling study of irrigation effects on global surface water and groundwater resources under a changing climate

    SciTech Connect (OSTI)

    Leng, Guoyong; Huang, Maoyi; Tang, Qiuhong; Leung, Lai-Yung R.

    2015-08-25

    Abstract In this study, the effects of irrigation on global surface water (SW) and groundwater (GW) resources are investigated by performing simulations using Community Land Model 4.0 (CLM4) at 0.5-degree resolution driven by downscaled/bias-corrected historical simulations and future projections from five General Circulation Models (GCMs) for 1950-2099. For each climate scenario, three sets of numerical experiments were configured: (1) a control experiment (CTRL) in which all crops are assumed to be rainfed; (2) an irrigation experiment (IRRIG) in which the irrigation module using only SW for irrigation is activated; and (3) a groundwater pumping experiment (PUMP) in which a groundwater pumping scheme coupled with the irrigation module is activated for conjunctive use of SW and GW for irrigation. The parameters associated with irrigation and groundwater pumping are calibrated based on a global inventory of census-based SW and GW use compiled by the Food and Agricultural Organization (FAO). Our results suggest that irrigation could lead to two major opposing effects: SW depletion/GW accumulation in regions with irrigation primarily fed by SW, and SW accumulation/GW depletion in regions with irrigation fed primarily by GW. Furthermore, irrigation depending primarily on SW tends to have larger impacts on low-flow than high-flow conditions, suggesting the potential to increase vulnerability to drought. By the end of the 21st century (2070-2099), climate change significantly increases (relative to 1971-2000) irrigation water demand across the world. Combined with the increased temporal-spatial variability of water supply, this may lead to severe issues of local water scarcity for irrigation. Regionally, irrigation has the potential to aggravate/alleviate climate-induced changes of SW/GW although such effects are negligible when averaged globally. Our results emphasize the importance of accounting for irrigation effects and irrigation sources in regional climate change

  18. A modeling study of irrigation effects on global surface water and groundwater resources under a changing climate

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Leng, Guoyong; Huang, Maoyi; Tang, Qiuhong; Leung, Lai-Yung R.

    2015-08-25

    In this paper, the effects of irrigation on global surface water (SW) and groundwater (GW) resources are investigated by performing simulations using Community Land Model 4.0 (CLM4) at 0.5-degree resolution driven by downscaled/bias-corrected historical simulations and future projections from five General Circulation Models (GCMs) for 1950-2099. For each climate scenario, three sets of numerical experiments were configured: (1) a control experiment (CTRL) in which all crops are assumed to be rainfed; (2) an irrigation experiment (IRRIG) in which the irrigation module using only SW for irrigation is activated; and (3) a groundwater pumping experiment (PUMP) in which a groundwater pumpingmore » scheme coupled with the irrigation module is activated for conjunctive use of SW and GW for irrigation. The parameters associated with irrigation and groundwater pumping are calibrated based on a global inventory of census-based SW and GW use compiled by the Food and Agricultural Organization (FAO). Our results suggest that irrigation could lead to two major opposing effects: SW depletion/GW accumulation in regions with irrigation primarily fed by SW, and SW accumulation/GW depletion in regions with irrigation fed primarily by GW. Furthermore, irrigation depending primarily on SW tends to have larger impacts on low-flow than high-flow conditions, suggesting the potential to increase vulnerability to drought. By the end of the 21st century (2070-2099), climate change significantly increases (relative to 1971-2000) irrigation water demand across the world. Combined with the increased temporal-spatial variability of water supply, this may lead to severe issues of local water scarcity for irrigation. Regionally, irrigation has the potential to aggravate/alleviate climate-induced changes of SW/GW although such effects are negligible when averaged globally. Our results emphasize the importance of accounting for irrigation effects and irrigation sources in regional climate change

  19. Inversion of Gravity Data to Define the Pre-Cenozoic Surface and Regional Structures Possibly Influencing Groundwater Flow in the Rainier Mesa Region, Nye County, Nevada.

    SciTech Connect (OSTI)

    Thomas G. Hildenbrand; Geoffrey A. Phelps; Edward A. Mankinen

    2006-09-21

    A three-dimensional inversion of gravity data from the Rainier Mesa area and surrounding regions reveals a topographically complex pre-Cenozoic basement surface. This model of the depth to pre-Cenozoic basement rocks is intended for use in a 3D hydrogeologic model being constructed for the Rainier Mesa area. Prior to this study, our knowledge of the depth to pre-Cenozoic basement rocks was based on a regional model, applicable to general studies of the greater Nevada Test Site area but inappropriate for higher resolution modeling of ground-water flow across the Rainier Mesa area. The new model incorporates several changes that lead to significant improvements over the previous regional view. First, the addition of constraining wells, encountering old volcanic rocks lying above but near pre-Cenozoic basement, prevents modeled basement from being too shallow. Second, an extensive literature and well data search has led to an increased understanding of the change of rock density with depth in the vicinity of Rainier Mesa. The third, and most important change, relates to the application of several depth-density relationships in the study area instead of a single generalized relationship, thereby improving the overall model fit. In general, the pre-Cenozoic basement surface deepens in the western part of the study area, delineating collapses within the Silent Canyon and Timber Mountain caldera complexes, and shallows in the east in the Eleana Range and Yucca Flat regions, where basement crops out. In the Rainier Mesa study area, basement is generally shallow (< 1 km). The new model identifies previously unrecognized structures within the pre-Cenozoic basement that may influence ground-water flow, such as a shallow basement ridge related to an inferred fault extending northward from Rainier Mesa into Kawich Valley.

  20. Shock Desensitization Experiments and Reactive Flow Modeling...

    Office of Scientific and Technical Information (OSTI)

    Shock Desensitization Experiments and Reactive Flow Modeling on Self-Sustaining LX-17 Detonation Waves Citation Details In-Document Search Title: Shock Desensitization Experiments ...

  1. TOUGH2. Unsaturated Groundwater and Heat Transport Model

    SciTech Connect (OSTI)

    Pruess, K.

    1991-05-01

    TOUGH2 is a new and improved version of TOUGH. TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures (water, water with tracer; water, CO2; water, air; water, air, with vapor pressure lowering and water, hydrogen), facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. TOUGH2 is a multi-dimensional numerical model for simulating the coupled transport of water, vapor, air, and heat in porous and fractured media. The program provides options for specifying injection or withdrawal of heat and fluids. Although primarily designed for studies of high-level nuclear waste isolation in partially saturated geological media, it should also be useful for a wider range of problems in heat and moisture transfer, and in the drying of porous materials. For example, geothermal reservoir simulation problems can be handled simply by setting the air mass function equal to zero on input. The TOUGH2 simulator was developed for problems involving strongly heat-driven flow. To describe these phenomena a multi-phase approach to fluid and heat flow is used, which fully accounts for the movement of gaseous and liquid phases, their transport of latent and sensible heat, and phase transitions between liquid and vapor. TOUGH2 takes account of fluid flow in both liquid and gaseous phases occurring under pressure, viscous, and gravity forces according to Darcy`s law. Interference between the phases is represented by means of relative permeability functions. The code handles binary, but not Knudsen, diffusion in the gas phase and capillary and phase adsorption effects for the liquid phase. Heat transport occurs by means of conduction with thermal conductivity dependent on water saturation, convection, and binary diffusion, which includes both sensible and latent heat.

  2. Numerical Simulation of Groundwater Withdrawal at the Nevada Test Site

    SciTech Connect (OSTI)

    Carroll, Rosemary; Giroux, Brian; Pohll, Greg; Hershey, Ronald; Russell, Charles; Howcroft, William

    2004-01-28

    Alternative uses of the Nevada Test Site (NTS) may require large amounts of water to construct and/or operate. The only abundant source of water at the NTS is groundwater. This report describes preliminary modeling to quantify the amount of groundwater available for development from three hydrographic areas at the NTS. Modeling was conducted with a three-dimensional transient numerical groundwater flow model.

  3. Groundwater contamination from an inactive uranium mill tailings pile. 2. Application of a dynamic mixing model

    SciTech Connect (OSTI)

    Narashimhan, T.N.; White, A.F.; Tokunaga, T.

    1986-12-01

    At Riverton, Wyoming, low pH process waters from an abandoned uranium mill tailings pile have been infiltrating into and contaminating the shallow water table aquifer. The contamination process has been governed by transient infiltration rates, saturated-unsaturated flow, as well as transient chemical reactions between the many chemical species present in the mixing waters and the sediments. In the first part of this two-part series the authors presented field data as well as an interpretation based on a static mixing models. As an upper bound, the authors estimated that 1.7% of the tailings water had mixed with the native groundwater. In the present work they present the results of numerical investigation of the dynamic mixing process. The model, DYNAMIX (DYNamic MIXing), couples a chemical speciation algorithm, PHREEQE, with a modified form of the transport algorithm, TRUMP, specifically designed to handle the simultaneous migration of several chemical constituents. The overall problem of simulating the evolution and migration of the contaminant plume was divided into three sub problems that were solved in sequential stages. These were the infiltration problem, the reactive mixing problem, and the plume-migration problem. The results of the application agree reasonably with the detailed field data. The methodology developed in the present study demonstrates the feasibility of analyzing the evolution of natural hydrogeochemical systems through a coupled analysis of transient fluid flow as well as chemical reactions. It seems worthwhile to devote further effort toward improving the physicochemical capabilities of the model as well as to enhance its computational efficiency.

  4. Approximate Model for Turbulent Stagnation Point Flow.

    SciTech Connect (OSTI)

    Dechant, Lawrence

    2016-01-01

    Here we derive an approximate turbulent self-similar model for a class of favorable pressure gradient wedge-like flows, focusing on the stagnation point limit. While the self-similar model provides a useful gross flow field estimate this approach must be combined with a near wall model is to determine skin friction and by Reynolds analogy the heat transfer coefficient. The combined approach is developed in detail for the stagnation point flow problem where turbulent skin friction and Nusselt number results are obtained. Comparison to the classical Van Driest (1958) result suggests overall reasonable agreement. Though the model is only valid near the stagnation region of cylinders and spheres it nonetheless provides a reasonable model for overall cylinder and sphere heat transfer. The enhancement effect of free stream turbulence upon the laminar flow is used to derive a similar expression which is valid for turbulent flow. Examination of free stream enhanced laminar flow suggests that the rather than enhancement of a laminar flow behavior free stream disturbance results in early transition to turbulent stagnation point behavior. Excellent agreement is shown between enhanced laminar flow and turbulent flow behavior for high levels, e.g. 5% of free stream turbulence. Finally the blunt body turbulent stagnation results are shown to provide realistic heat transfer results for turbulent jet impingement problems.

  5. U-234/U-238 ratio: Qualitative estimate of groundwater flow in Rocky Flats monitoring wells

    SciTech Connect (OSTI)

    Laul, J.C.

    1994-02-01

    Groundwater movement through various pathways is the primary mechanism for the transport of radionuclides and trace elements in a water/rock interaction. About three dozen wells, installed in the Rocky Flats Plant (RFP) Solar Evaporation Ponds (SEP) area, are monitored quarterly to evaluate the extent of any lateral and downgradient migration of contaminants from the Solar Evaporation Ponds: 207-A; 207-B North, 207-B Center, and 207-B South; and 207-C. The Solar Ponds are the main source for the various contaminants: radionuclides (U-238, U-234, Pu-239, 240 and Am-241); anions; and trace metals to groundwaters. The U-238 concentrations in Rocky Flats groundwaters vary from <0.2 to 69 pCi/I (IpCi = 3 ug). However, the activity U-234/U-238 ratios are low and range mostly 1.2 to 2.7. The low activity ratios can be interpreted to suggest that the groundwaters are moving slow (

  6. Modeling study for the implementation of in situ cometabolic bioremediation of trichloroethylene-contaminated groundwater. Master`s Thesis

    SciTech Connect (OSTI)

    Christ, J.A.

    1997-12-01

    The limitations of conventional groundwater remediation technologies have led to the development of innovative technologies which may achieve national hazardous waste site remediation goals. Before an innovative technology can be implemented in the field, remedial project managers, regulators and other stakeholders require adequate modeling tools to help assess the applicability of the technology at a particular site. This modeling study investigates how an innovative technology, in situ cometabolic bioremediation, might be implemented to remediate a TCE-contaminated site, under different site conditions. A steady-state model is developed which couples an analytical expression to simulate the effect of flow between multiple pumping and injection wells, with an expression to calculate TCE removal as groundwater circulates through in situ bioreactors established around the injection wells. Varying site conditions and well configurations are investigated to determine their effect on the overall treatment efficiency of a system. A dual screen well design is found to be an effective method for contaminant capture and treatment given typical values of anisotropy. Investigation of a multiple row implementation concept proves it to be an effective configuration for site cleanup. The model is integrated into interactive software which serves as a technology screening tool.

  7. Flow and Containment Transport Code for Modeling Variably Saturated Porous Media

    Energy Science and Technology Software Center (OSTI)

    1998-05-14

    FACT is a finite element based code designed to model subsurface flow and contaminant transport. It was designed to perform transient three-dimensional calculations that simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media. The code is designed specifically to handle complex multi-layer and/or heterogenous aquifer systems in an efficient manner and accommodates a wide range of boundary conditions. Additionally 1-D and 2-D (in Cartesian coordinates) problemsmore »are handled in FACT by simply limiting the number of elements in a particular direction(s) to one. The governing equations in FACT are formulated only in Cartesian coordinates. FACT writes out both ascii and graphical binary files that are TECPLOT-ready. Special features are also available within FACT for handling the typical groundwater modeling needs for remediation efforts at the Savannah River Site.« less

  8. Flow and Containment Transport Code for Modeling Variably Saturated Porous Media

    Energy Science and Technology Software Center (OSTI)

    1998-05-14

    FACT is a finite element based code designed to model subsurface flow and contaminant transport. It was designed to perform transient three-dimensional calculations that simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media. The code is designed specifically to handle complex multi-layer and/or heterogenous aquifer systems in an efficient manner and accommodates a wide range of boundary conditions. Additionally 1-D and 2-D (in Cartesian coordinates) problemsmore » are handled in FACT by simply limiting the number of elements in a particular direction(s) to one. The governing equations in FACT are formulated only in Cartesian coordinates. FACT writes out both ascii and graphical binary files that are TECPLOT-ready. Special features are also available within FACT for handling the typical groundwater modeling needs for remediation efforts at the Savannah River Site.« less

  9. Transient Wellbore Fluid Flow Model

    Energy Science and Technology Software Center (OSTI)

    1982-04-06

    WELBORE is a code to solve transient, one-dimensional two-phase or single-phase non-isothermal fluid flow in a wellbore. The primary thermodynamic variables used in solving the equations are the pressure and specific energy. An equation of state subroutine provides the density, quality, and temperature. The heat loss out of the wellbore is calculated by solving a radial diffusion equation for the temperature changes outside the bore. The calculation is done at each node point in themore » wellbore.« less

  10. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    SciTech Connect (OSTI)

    K. Rehfeldt

    2004-10-08

    This report is an updated analysis of water-level data performed to provide the ''Saturated Zone Site-Scale Flow Model'' (BSC 2004 [DIRS 170037]) (referred to as the saturated zone (SZ) site-scale flow model or site-scale SZ flow model in this report) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for calibration of groundwater flow models. This report also contains an expanded discussion of uncertainty in the potentiometric-surface map. The analysis of the potentiometric data presented in Revision 00 of this report (USGS 2001 [DIRS 154625]) provides the configuration of the potentiometric surface, target heads, and hydraulic gradients for the calibration of the SZ site-scale flow model (BSC 2004 [DIRS 170037]). Revision 01 of this report (USGS 2004 [DIRS 168473]) used updated water-level data for selected wells through the year 2000 as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain based on an alternative interpretation of perched water conditions. That revision developed computer files containing: Water-level data within the model area (DTN: GS010908312332.002); A table of known vertical head differences (DTN: GS010908312332.003); and A potentiometric-surface map (DTN: GS010608312332.001) using an alternative concept from that presented by USGS (2001 [DIRS 154625]) for the area north of Yucca Mountain. The updated water-level data presented in USGS (2004 [DIRS 168473]) include data obtained from the Nye County Early Warning Drilling Program (EWDP) Phases I and II and data from Borehole USW WT-24. This document is based on Revision 01 (USGS 2004 [DIRS 168473]) and expands the discussion of uncertainty in the potentiometric-surface map. This uncertainty assessment includes an analysis of the impact of more recent water-level data and the impact of adding data from the EWDP Phases III and IV wells. In addition to being utilized

  11. General single phase wellbore flow model

    SciTech Connect (OSTI)

    Ouyang, Liang-Biao; Arbabi, S.; Aziz, K.

    1997-02-05

    A general wellbore flow model, which incorporates not only frictional, accelerational and gravitational pressure drops, but also the pressure drop caused by inflow, is presented in this report. The new wellbore model is readily applicable to any wellbore perforation patterns and well completions, and can be easily incorporated in reservoir simulators or analytical reservoir inflow models. Three dimensionless numbers, the accelerational to frictional pressure gradient ratio R{sub af}, the gravitational to frictional pressure gradient ratio R{sub gf}, and the inflow-directional to accelerational pressure gradient ratio R{sub da}, have been introduced to quantitatively describe the relative importance of different pressure gradient components. For fluid flow in a production well, it is expected that there may exist up to three different regions of the wellbore: the laminar flow region, the partially-developed turbulent flow region, and the fully-developed turbulent flow region. The laminar flow region is located near the well toe, the partially-turbulent flow region lies in the middle of the wellbore, while the fully-developed turbulent flow region is at the downstream end or the heel of the wellbore. Length of each region depends on fluid properties, wellbore geometry and flow rate. As the distance from the well toe increases, flow rate in the wellbore increases and the ratios R{sub af} and R{sub da} decrease. Consequently accelerational and inflow-directional pressure drops have the greatest impact in the toe region of the wellbore. Near the well heel the local wellbore flow rate becomes large and close to the total well production rate, here R{sub af} and R{sub da} are small, therefore, both the accelerational and inflow-directional pressure drops can be neglected.

  12. A compendium of fracture flow models, 1994

    SciTech Connect (OSTI)

    Diodato, D.M.

    1994-11-01

    The report is designed to be used as a decision-making aid for individuals who need to simulate fluid flow in fractured porous media. Fracture flow codes of varying capability in the public and private domain were identified in a survey of government, academia, and industry. The selection and use of an appropriate code requires conceptualization of the geology, physics, and chemistry (for transport) of the fracture flow problem to be solved. Conceptual models that have been invoked to describe fluid flow in fractured porous media include explicit discrete fracture, dual continuum (porosity and/or permeability), discrete fracture network, multiple interacting continua, multipermeability/multiporosity, and single equivalent continuum. The explicit discrete-fracture model is a ``near-field`` representation, the single equivalent continuum model is a ``far-field`` representation, and the dual-continuum model is intermediate to those end members. Of these, the dual-continuum model is the most widely employed. The concept of multiple interacting continua has been applied in a limited number of examples. Multipermeability/multiporosity provides a unified conceptual model. The ability to accurately describe fracture flow phenomena will continue to improve as a result of advances in fracture flow research and computing technology. This improvement will result in enhanced capability to protect the public environment, safety, and health.

  13. A Hybrid MPI/OpenMP Approach for Parallel Groundwater Model Calibration on Multicore Computers

    SciTech Connect (OSTI)

    Tang, Guoping; D'Azevedo, Ed F; Zhang, Fan; Parker, Jack C.; Watson, David B; Jardine, Philip M

    2010-01-01

    Groundwater model calibration is becoming increasingly computationally time intensive. We describe a hybrid MPI/OpenMP approach to exploit two levels of parallelism in software and hardware to reduce calibration time on multicore computers with minimal parallelization effort. At first, HydroGeoChem 5.0 (HGC5) is parallelized using OpenMP for a uranium transport model with over a hundred species involving nearly a hundred reactions, and a field scale coupled flow and transport model. In the first application, a single parallelizable loop is identified to consume over 97% of the total computational time. With a few lines of OpenMP compiler directives inserted into the code, the computational time reduces about ten times on a compute node with 16 cores. The performance is further improved by selectively parallelizing a few more loops. For the field scale application, parallelizable loops in 15 of the 174 subroutines in HGC5 are identified to take more than 99% of the execution time. By adding the preconditioned conjugate gradient solver and BICGSTAB, and using a coloring scheme to separate the elements, nodes, and boundary sides, the subroutines for finite element assembly, soil property update, and boundary condition application are parallelized, resulting in a speedup of about 10 on a 16-core compute node. The Levenberg-Marquardt (LM) algorithm is added into HGC5 with the Jacobian calculation and lambda search parallelized using MPI. With this hybrid approach, compute nodes at the number of adjustable parameters (when the forward difference is used for Jacobian approximation), or twice that number (if the center difference is used), are used to reduce the calibration time from days and weeks to a few hours for the two applications. This approach can be extended to global optimization scheme and Monte Carol analysis where thousands of compute nodes can be efficiently utilized.

  14. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    SciTech Connect (OSTI)

    P. Tucci

    2001-12-20

    This Analysis/Model Report (AMR) documents an updated analysis of water-level data performed to provide the saturated-zone, site-scale flow and transport model (CRWMS M&O 2000) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for model calibration. The previous analysis was presented in ANL-NBS-HS-000034, Rev 00 ICN 01, Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model (USGS 2001). This analysis is designed to use updated water-level data as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain. The objectives of this revision are to develop computer files containing (1) water-level data within the model area (DTN: GS010908312332.002), (2) a table of known vertical head differences (DTN: GS0109083 12332.003), and (3) a potentiometric-surface map (DTN: GS010608312332.001) using an alternate concept from that presented in ANL-NBS-HS-000034, Rev 00 ICN 01 for the area north of Yucca Mountain. The updated water-level data include data obtained from the Nye County Early Warning Drilling Program (EWDP) and data from borehole USW WT-24. In addition to being utilized by the SZ site-scale flow and transport model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for ground-water management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model, as well as provides information useful to estimation of the magnitude and direction of lateral ground-water flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment.

  15. Scaled Experimental Modeling of VHTR Plenum Flows

    SciTech Connect (OSTI)

    ICONE 15

    2007-04-01

    Abstract The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. Various scaled heated gas and water flow facilities were investigated for modeling VHTR upper and lower plenum flows during the decay heat portion of a pressurized conduction-cooldown scenario and for modeling thermal mixing and stratification (thermal striping) in the lower plenum during normal operation. It was concluded, based on phenomena scaling and instrumentation and other practical considerations, that a heated water flow scale model facility is preferable to a heated gas flow facility and to unheated facilities which use fluids with ranges of density to simulate the density effect of heating. For a heated water flow lower plenum model, both the Richardson numbers and Reynolds numbers may be approximately matched for conduction-cooldown natural circulation conditions. Thermal mixing during normal operation may be simulated but at lower, but still fully turbulent, Reynolds numbers than in the prototype. Natural circulation flows in the upper plenum may also be simulated in a separate heated water flow facility that uses the same plumbing as the lower plenum model. However, Reynolds number scaling distortions will occur at matching Richardson numbers due primarily to the necessity of using a reduced number of channels connected to the plenum than in the prototype (which has approximately 11,000 core channels connected to the upper plenum) in an otherwise geometrically scaled model. Experiments conducted in either or both facilities will meet the objectives of providing benchmark data for the validation of codes proposed for NGNP designs and safety studies, as well as providing a better understanding of the complex flow phenomena in the plenums.

  16. Modeling fluid flow in deformation bands with stabilized localization...

    Office of Scientific and Technical Information (OSTI)

    Modeling fluid flow in deformation bands with stabilized localization mixed finite elements. Citation Details In-Document Search Title: Modeling fluid flow in deformation bands...

  17. Charge flow model for atomic ordering in nonisovalent alloys...

    Office of Scientific and Technical Information (OSTI)

    Charge flow model for atomic ordering in nonisovalent alloys Title: Charge flow model for atomic ordering in nonisovalent alloys Authors: Wang, Shuzhi ; Wang, Lin-Wang Publication ...

  18. A model for transonic plasma flow

    SciTech Connect (OSTI)

    Guazzotto, Luca; Hameiri, Eliezer

    2014-02-15

    A linear, two-dimensional model of a transonic plasma flow in equilibrium is constructed and given an explicit solution in the form of a complex Laplace integral. The solution indicates that the transonic state can be solved as an elliptic boundary value problem, as is done in the numerical code FLOW [Guazzotto et al., Phys. Plasmas 11, 604 (2004)]. Moreover, the presence of a hyperbolic region does not necessarily imply the presence of a discontinuity or any other singularity of the solution.

  19. Groundwater monitoring program plan and conceptual site model for the Al-Tuwaitha Nuclear Research Center in Iraq.

    SciTech Connect (OSTI)

    Copland, John Robin; Cochran, John Russell

    2013-07-01

    The Radiation Protection Center of the Iraqi Ministry of Environment is developing a groundwater monitoring program (GMP) for the Al-Tuwaitha Nuclear Research Center located near Baghdad, Iraq. The Al-Tuwaitha Nuclear Research Center was established in about 1960 and is currently being cleaned-up and decommissioned by Iraq's Ministry of Science and Technology. This Groundwater Monitoring Program Plan (GMPP) and Conceptual Site Model (CSM) support the Radiation Protection Center by providing:A CSM describing the hydrogeologic regime and contaminant issues,recommendations for future groundwater characterization activities, anddescriptions of the organizational elements of a groundwater monitoring program. The Conceptual Site Model identifies a number of potential sources of groundwater contamination at Al-Tuwaitha. The model also identifies two water-bearing zones (a shallow groundwater zone and a regional aquifer). The depth to the shallow groundwater zone varies from approximately 7 to 10 meters (m) across the facility. The shallow groundwater zone is composed of a layer of silty sand and fine sand that does not extend laterally across the entire facility. An approximately 4-m thick layer of clay underlies the shallow groundwater zone. The depth to the regional aquifer varies from approximately 14 to 17 m across the facility. The regional aquifer is composed of interfingering layers of silty sand, fine-grained sand, and medium-grained sand. Based on the limited analyses described in this report, there is no severe contamination of the groundwater at Al-Tuwaitha with radioactive constituents. However, significant data gaps exist and this plan recommends the installation of additional groundwater monitoring wells and conducting additional types of radiological and chemical analyses.

  20. Groundwater in the Regional Aquifer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater in the Regional Aquifer Groundwater in the Regional Aquifer LANL maintains an ... August 1, 2013 Conceptual model of water movement and geology at Los Alamos National ...

  1. Slurry fired heater cold-flow modelling

    SciTech Connect (OSTI)

    Moujaes, S.F.

    1983-07-01

    This report summarizes the experimental and theoretical work leading to the scale-up of the SRC-I Demonstration Plant slurry fired heater. The scale-up involved a theoretical model using empirical relations in the derivation, and employed variables such as flow conditions, liquid viscosity, and slug frequency. Such variables have been shown to affect the heat transfer characteristics ofthe system. The model assumes that, if all other variables remain constant, the heat transfer coefficient can be scaled up proportional to D/sup -2/3/ (D = inside diameter of the fired heater tube). All flow conditions, liquid viscosities, and pipe inclinations relevant to the demonstration plant have indicated a slug flow regime in the slurry fired heater. The annular and stratified flow regimes should be avoided to minimize the potential for excessive pipe erosion and to decrease temperature gradients along the pipe cross section leading to coking and thermal stresses, respectively. Cold-flow studies in 3- and 6.75-in.-inside-diameter (ID) pipes were conducted to determine the effect of scale-up on flow regime, slug frequency, and slug dimensions. The developed model assumes that conduction heat transfer occurs through the liquid film surrounding the gas slug and laminar convective heat transfer to the liquid slug. A weighted average of these two heat transfer mechanisms gives a value for the average pipe heat transfer coefficient. The cold-flow work showed a decrease in the observed slug frequency between the 3- and 6.75-ID pipes. Data on the ratio of gas to liquid slug length in the 6.75-in. pipe are not yet complete, but are expected to yield generally lower values than those obtained in the 3-in. pipe; this will probably affect the scale-up to demonstration plant conditions. 5 references, 15 figures, 7 tables.

  2. A saturated zone site-scale flow model for Yucca mountain

    SciTech Connect (OSTI)

    Eddebbarh, Al Aziz

    2008-01-01

    A saturated zone site-scale flow model (YMSZFM) was developed for licensing requirements for the Yucca Mountain nuclear waste repository to incorporate recent data and analyses including recent stratigraphic and water-level data from Nye County wells, single-and multiple-well hydraulic testing data, and recent hydrochemistry data. Analyses include use of data from the 2004 transient Death Valley Regional (ground-water) Flow System (DVRFS) model, the 2003 unsaturated zone flow model, and the latest hydrogeologic framework model (HFM). This model includes: (1) the latest understanding of SZ flow, (2) enhanced model validation and uncertainty analyses, (3) improved locations and definitions of fault zones, (4) refined grid resolution (500-to 250-m grid spacing), and (5) use of new data. The flow model was completed using the three-dimensional, Finite-Element Heat and Mass Transfer computer code (FEHM). The SZ site-scale flow model was calibrated with the commercial parameter estimation code, PEST to achieve a minimum difference between observed water levels and predicted water levels, and also between volumetric/mass flow rates along specific boundary segments as supplied by the DVRFS. A total of 161 water level and head measurements with varied weights were used for calibration. A comparison between measured water-level data and the potentiometric surface yielded an RMSE of 20.7 m (weighted RMSE of 8.8 m). The calibrated model was used to generate flow paths and specific discharge predictions. Model confidence was built by comparing: (l) calculated to observed hydraulic heads, and (2) calibrated to measured permeabilities (and therefore specific discharge). In addition, flowpaths emanating from below the repository footprint are consistent with those inferred both from gradients of measured head and from independent water-chemistry data. Uncertainties in the SZ site-scale flow model were quantified because all uncertainty contributes to inaccuracy in system

  3. Tritium monitoring in groundwater and evaluation of model predictions for the Hanford Site 200 Area Effluent Treatment Facility

    SciTech Connect (OSTI)

    Barnett, D.B.; Bergeron, M.P.; Cole, C.R.; Freshley, M.D.; Wurstner, S.K.

    1997-08-01

    The Effluent Treatment Facility (ETF) disposal site, also known as the State-Approved Land Disposal Site (SALDS), receives treated effluent containing tritium, which is allowed to infiltrate through the soil column to the water table. Tritium was first detected in groundwater monitoring wells around the facility in July 1996. The SALDS groundwater monitoring plan requires revision of a predictive groundwater model and reevaluation of the monitoring well network one year from the first detection of tritium in groundwater. This document is written primarily to satisfy these requirements and to report on analytical results for tritium in the SALDS groundwater monitoring network through April 1997. The document also recommends an approach to continued groundwater monitoring for tritium at the SALDS. Comparison of numerical groundwater models applied over the last several years indicate that earlier predictions, which show tritium from the SALDS approaching the Columbia River, were too simplified or overly robust in source assumptions. The most recent modeling indicates that concentrations of tritium above 500 pCi/L will extend, at most, no further than {approximately}1.5 km from the facility, using the most reasonable projections of ETF operation. This extent encompasses only the wells in the current SALDS tritium-tracking network.

  4. Reactive chemical transport in ground-water hydrology: Challenges to mathematical modeling

    SciTech Connect (OSTI)

    Narasimhan, T.N.; Apps, J.A.

    1990-07-01

    For a long time, earth scientists have qualitatively recognized that mineral assemblages in soils and rocks conform to established principles of chemistry. In the early 1960's geochemists began systematizing this knowledge by developing quantitative thermodynamic models based on equilibrium considerations. These models have since been coupled with advective-dispersive-diffusive transport models, already developed by ground-water hydrologists. Spurred by a need for handling difficult environmental issues related to ground-water contamination, these models are being improved, refined and applied to realistic problems of interest. There is little doubt that these models will play an important role in solving important problems of engineering as well as science over the coming years. Even as these models are being used practically, there is scope for their improvement and many challenges lie ahead. In addition to improving the conceptual basis of the governing equations, much remains to be done to incorporate kinetic processes and biological mediation into extant chemical equilibrium models. Much also remains to be learned about the limits to which model predictability can be reasonably taken. The purpose of this paper is to broadly assess the current status of knowledge in modeling reactive chemical transport and to identify the challenges that lie ahead.

  5. Mutiscale Modeling of Segregation in Granular Flows

    SciTech Connect (OSTI)

    Jin Sun

    2007-08-03

    Modeling and simulation of segregation phenomena in granular flows are investigated. Computational models at different scales ranging from particle level (microscale) to continuum level (macroscale) are employed in order to determine the important microscale physics relevant to macroscale modeling. The capability of a multi-fluid model to capture segregation caused by density difference is demonstrated by simulating grain-chaff biomass flows in a laboratory-scale air column and in a combine harvester. The multi-fluid model treats gas and solid phases as interpenetrating continua in an Eulerian frame. This model is further improved by incorporating particle rotation using kinetic theory for rapid granular flow of slightly frictional spheres. A simplified model is implemented without changing the current kinetic theory framework by introducing an effective coefficient of restitution to account for additional energy dissipation due to frictional collisions. The accuracy of predicting segregation rate in a gas-fluidized bed is improved by the implementation. This result indicates that particle rotation is important microscopic physics to be incorporated into the hydrodynamic model. Segregation of a large particle in a dense granular bed of small particles under vertical. vibration is studied using molecular dynamics simulations. Wall friction is identified as a necessary condition for the segregation. Large-scale force networks bearing larger-than-average forces are found with the presence of wall friction. The role of force networks in assisting rising of the large particle is analyzed. Single-point force distribution and two-point spatial force correlation are computed. The results show the heterogeneity of forces and a short-range correlation. The short correlation length implies that even dense granular flows may admit local constitutive relations. A modified minimum spanning tree (MST) algorithm is developed to asymptotically recover the force statistics in the

  6. Status of understanding of the saturated-zone ground-water flow system at Yucca Mountain, Nevada, as of 1995

    SciTech Connect (OSTI)

    Luckey, R.R.; Tucci, P.; Faunt, C.C.; Ervin, E.M.

    1996-12-31

    Yucca Mountain, which is being studied extensively because it is a potential site for a high-level radioactive-waste repository, consists of a thick sequence of volcanic rocks of Tertiary age that are underlain, at least to the southeast, by carbonate rocks of Paleozoic age. Stratigraphic units important to the hydrology of the area include the alluvium, pyroclastic rocks of Miocene age (the Timber Mountain Group; the Paintbrush Group; the Calico Hills Formation; the Crater Flat Group; the Lithic Ridge Tuff; and older tuffs, flows, and lavas beneath the Lithic Ridge Tuff), and sedimentary rocks of Paleozoic age. The saturated zone generally occurs in the Calico Hills Formation and stratigraphically lower units. The saturated zone is divided into three aquifers and two confining units. The flow system at Yucca Mountain is part of the Alkali Flat-Furnace Creek subbasin of the Death Valley groundwater basin. Variations in the gradients of the potentiometric surface provided the basis for subdividing the Yucca Mountain area into zones of: (1) large hydraulic gradient where potentiometric levels change at least 300 meters in a few kilometers; (2) moderate hydraulic gradient where potentiometric levels change about 45 meters in a few kilometers; and (3) small hydraulic gradient where potentiometric levels change only about 2 meters in several kilometers. Vertical hydraulic gradients were measured in only a few boreholes around Yucca Mountain; most boreholes had little change in potentiometric levels with depth. Limited hydraulic testing of boreholes in the Yucca Mountain area indicated that the range in transmissivity was more than 2 to 3 orders of magnitude in a particular hydrogeologic unit, and that the average values for the individual hydrogeologic units generally differed by about 1 order of magnitude. The upper volcanic aquifer seems to be the most permeable hydrogeologic unit, but this conclusion was based on exceedingly limited data.

  7. Boundary element method using B-splines with applications to groundwater flow

    SciTech Connect (OSTI)

    Cabral, J.J.S.P.

    1992-01-01

    The Boundary Element Method (BEM) is now established as a suitable and efficient technique for the analysis of engineering problems. However, as in other discretization procedures, inaccuracies can be introduced as a result of the lack of derivative continuity between adjacent elements. A new element formulation has been developed for BEM analysis using uniform cubic B-splines. These functions can be employed to provide higher degrees of continuity along the geometric boundary of the region, and also as interpolation functions for the problem variables. The formulation was then extended to include multiple knots and non-uniform blending functions. In this way, it is possible to lower the degree of continuity of the main variable at points of geometric discontinuity. Initially, applications are presented related to potential problems governed by Laplace's equation but there are no restrictions in the formulation regarding its extension to other physical problems. Continuity of the derivatives of the main variable is important to obtain a good representation of moving boundaries with iterative or time-marching schemes. This formulation is applied to stead-state and transient unconfined flow in homogeneous and inhomogeneous porous media. Finally, the formulation is applied to saltwater intrusion problems in confined, leaky and unconfined aquifers.

  8. Can We Accurately Model Fluid Flow in Shale?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Can We Accurately Model Fluid Flow in Shale? Can We Accurately Model Fluid Flow in Shale? Print Thursday, 03 January 2013 00:00 Over 20 trillion cubic meters of natural gas are...

  9. Observing and modeling Earths energy flows

    SciTech Connect (OSTI)

    Stevens B.; Schwartz S.

    2012-05-11

    This article reviews, from the authors perspective, progress in observing and modeling energy flows in Earth's climate system. Emphasis is placed on the state of understanding of Earth's energy flows and their susceptibility to perturbations, with particular emphasis on the roles of clouds and aerosols. More accurate measurements of the total solar irradiance and the rate of change of ocean enthalpy help constrain individual components of the energy budget at the top of the atmosphere to within {+-}2 W m{sup -2}. The measurements demonstrate that Earth reflects substantially less solar radiation and emits more terrestrial radiation than was believed even a decade ago. Active remote sensing is helping to constrain the surface energy budget, but new estimates of downwelling surface irradiance that benefit from such methods are proving difficult to reconcile with existing precipitation climatologies. Overall, the energy budget at the surface is much more uncertain than at the top of the atmosphere. A decade of high-precision measurements of the energy budget at the top of the atmosphere is providing new opportunities to track Earth's energy flows on timescales ranging from days to years, and at very high spatial resolution. The measurements show that the principal limitation in the estimate of secular trends now lies in the natural variability of the Earth system itself. The forcing-feedback-response framework, which has developed to understand how changes in Earth's energy flows affect surface temperature, is reviewed in light of recent work that shows fast responses (adjustments) of the system are central to the definition of the effective forcing that results from a change in atmospheric composition. In many cases, the adjustment, rather than the characterization of the compositional perturbation (associated, for instance, with changing greenhouse gas concentrations, or aerosol burdens), limits accurate determination of the radiative forcing. Changes in clouds

  10. Subsurface Multiphase Flow and Multicomponent Reactive Transport Modeling using High-Performance Computing

    SciTech Connect (OSTI)

    Hammond, Glenn E.; Lichtner, Peter C.; Lu, Chuan

    2007-08-01

    Numerical modeling has become a critical tool to the Department of Energy for evaluating the environmental impact of alternative energy sources and remediation strategies for legacy waste sites. Unfortunately, the physical and chemical complexity of many sites overwhelms the capabilities of even most state of the art groundwater models. Of particular concern are the representation of highly-heterogeneous stratified rock/soil layers in the subsurface and the biological and geochemical interactions of chemical species within multiple fluid phases. Clearly, there is a need for higher-resolution modeling (i.e. more spatial, temporal, and chemical degrees of freedom) and increasingly mechanistic descriptions of subsurface physicochemical processes. We present research being performed in the development of PFLOTRAN, a parallel multiphase flow and multicomponent reactive transport model. Written in Fortran90, PFLOTRAN is founded upon PETSc data structures and solvers and has exhibited impressive strong scalability on up to 4000 processors on the ORNL Cray XT3. We are employing PFLOTRAN in the simulation of uranium transport at the Hanford 300 Area, a contaminated site of major concern to the Department of Energy, the State of Washington, and other government agencies where overly-simplistic historical modeling erroneously predicted decade removal times for uranium by ambient groundwater flow. By leveraging the billions of degrees of freedom available through high-performance computation using tens of thousands of processors, we can better characterize the release of uranium into groundwater and its subsequent transport to the Columbia River, and thereby better understand and evaluate the effectiveness of various proposed remediation strategies.

  11. DYNAMIC MODELING STRATEGY FOR FLOW REGIME TRANSITION IN GAS-LIQUID TWO-PHASE FLOWS

    SciTech Connect (OSTI)

    X. Wang; X. Sun; H. Zhao

    2011-09-01

    In modeling gas-liquid two-phase flows, the concept of flow regime has been used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are often flow regime dependent. Currently, the determination of the flow regimes is primarily based on flow regime maps or transition criteria, which are developed for steady-state, fully-developed flows and widely applied in nuclear reactor system safety analysis codes, such as RELAP5. As two-phase flows are observed to be dynamic in nature (fully-developed two-phase flows generally do not exist in real applications), it is of importance to model the flow regime transition dynamically for more accurate predictions of two-phase flows. The present work aims to develop a dynamic modeling strategy for determining flow regimes in gas-liquid two-phase flows through the introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation and destruction of the interfacial area, such as the fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation; and fluid particle coalescence and condensation, respectively. For the flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shape (which are correlated), namely small bubbles and large bubbles. A preliminary approach to dynamically identifying the flow regimes is provided, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration of small bubble and large bubble groups. This method is expected to be applied to computer codes to improve their predictive capabilities of gas-liquid two-phase flows, in particular for the applications in

  12. Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    in EGS Reservoirs | Department of Energy Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Project objectives: Improve image resolution for microseismicimaging and time-lapse active seismic imaging; Enhance the prediction of fluid flow and temperature distributions and stress changes by coupling fracture flow simulations with reservoir flow simulations; and

  13. Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    EGS Reservoir Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir Project ... More Documents & Publications Imaging, Characterizing, and Modeling of Fracture Networks ...

  14. Data Package for Past and Current Groundwater Flow and Contamination beneath Single-Shell Tank Waste Management Areas

    SciTech Connect (OSTI)

    Horton, Duane G.

    2007-03-16

    This appendix summarizes historic and recent groundwater data collected from the uppermost aquifer beneath the 200 East and 200 West Areas. Although the area of interest is the Hanford Site Central Plateau, most of the information discussed in this appendix is at the scale of individual single-shell tank waste management areas. This is because the geologic, and thus the hydraulic, properties and the geochemical properties (i.e., groundwater composition) are different in different parts of the Central Plateau.

  15. Wellbore and groundwater temperature distribution eastern Snake River

    Office of Scientific and Technical Information (OSTI)

    Plain, Idaho: Implications for groundwater flow and geothermal potential (Journal Article) | SciTech Connect Journal Article: Wellbore and groundwater temperature distribution eastern Snake River Plain, Idaho: Implications for groundwater flow and geothermal potential Citation Details In-Document Search Title: Wellbore and groundwater temperature distribution eastern Snake River Plain, Idaho: Implications for groundwater flow and geothermal potential A map of groundwater temperatures from

  16. Porosity distribution in Wolfcamp strata, Palo Duro basin, Texas panhandle: implications for deep-basin ground-water flow

    SciTech Connect (OSTI)

    Conti, R.D.; Wirojanagud, P.

    1984-04-01

    Average-porosity distributions in the Wolfcamp deep-basin aquifer are critical to discernment of the geographic trends in effective-porosity in the Palo Duro basin. Precise data are used to improved resolution of porosity values for computer-simulated areal ground-water modeling. Assessing vertical distributions of lithology and porosity in each well studied involves analysis of crossplotted neutron- and density-porosity log responses. This method more accurately identifies lithology and porosity than does the commonly employed crossplotted neutron-porosity and sonic (interval travel time) responses. Log-derived average-porosity distributions yield information about effective pore volume (i.e., movable water) in the Wolfcamp aquifer and enhance the accuracy of estimated of travel times and velocities of brines in basinwide traverses. Mathematical analysis of average travel time and total effective pore volume yield estimates of the rates of annual discharge from the Wolfcamp aquifer in the Palo Duro basin. Based on average flush rates between 2.2 and 1.5 m.y., annual discharge rates from the Wolfcamp aquifer across the northern and eastern basin boundaries, are about 3.6 x 10/sup 5/ m/sup 3/ year/sup -1/ to 5.3 x 10/sup 5/m/sup 3/ year/sup -1/.

  17. Dynamic Modeling Strategy for Flow Regime Transition in Gas-Liquid Two-Phase Flows

    SciTech Connect (OSTI)

    Xia Wang; Xiaodong Sun; Benjamin Doup; Haihua Zhao

    2012-12-01

    In modeling gas-liquid two-phase flows, the concept of flow regimes has been widely used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are flow regime dependent. Current nuclear reactor safety analysis codes, such as RELAP5, classify flow regimes using flow regime maps or transition criteria that were developed for steady-state, fully-developed flows. As twophase flows are dynamic in nature, it is important to model the flow regime transitions dynamically to more accurately predict the two-phase flows. The present work aims to develop a dynamic modeling strategy to determine flow regimes in gas-liquid two-phase flows through introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation of the interfacial area, fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation, and the destruction of the interfacial area, fluid particle coalescence and condensation. For flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shapes, namely group-1 and group-2 bubbles. A preliminary approach to dynamically identify the flow regimes is discussed, in which discriminator s are based on the predicted information, such as the void fraction and interfacial area concentration. The flow regime predicted with this method shows good agreement with the experimental observations.

  18. Numerical simulation model for vertical flow in geothermal wells

    SciTech Connect (OSTI)

    Tachimori, M.

    1982-01-01

    A numerical simulation model for vertical flow in geothermal wells is presented. The model consists of equations for the conservation of mass, momentum, and energy, for thermodynamic state of water, for friction losses, for slip velocity relations, and of the criteria for various flow regimes. A new set of correlations and criteria is presented for two-phase flow to improve the accuracy of predictions; bubbly flow - Griffith and Wallis correlation, slug flow - Nicklin et al. one, annular-mist flow - Inoue and Aoki and modified by the author. The simulation method was verified by data from actual wells.

  19. Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy EGS Reservoir Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir Project objectives: Better understand and model fluid injection into a tight reservoir on the edges of a hydrothermal field. Use seismic data to constrain geomechanical/hydrologic/thermal model of reservoir. seismic_fehler_fluid_flow.pdf (1.15 MB) More Documents & Publications Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Detection and

  20. Binary fish passage models for uniform and nonuniform flows

    SciTech Connect (OSTI)

    Neary, Vincent S

    2011-01-01

    Binary fish passage models are considered by many fisheries managers to be the best 21 available practice for culvert inventory assessments and for fishway and barrier design. 22 Misunderstandings between different binary passage modeling approaches often arise, 23 however, due to differences in terminology, application and presentation. In this paper 24 one-dimensional binary fish passage models are reviewed and refined to clarify their 25 origins and applications. For uniform flow, a simple exhaustion-threshold (ET) model 26 equation is derived that predicts the flow speed threshold in a fishway or velocity barrier 27 that causes exhaustion at a given maximum distance of ascent. Flow speeds at or above 28 the threshold predict failure to pass (exclusion). Flow speeds below the threshold predict 29 passage. The binary ET model is therefore intuitive and easily applied to predict passage 30 or exclusion. It is also shown to be consistent with the distance-maximizing model. The 31 ET model s limitation to uniform flow is addressed by deriving a passage model that 32 accounts for nonuniform flow conditions more commonly found in the field, including 33 backwater profiles and drawdown curves. Comparison of these models with 34 experimental observations of volitional passage for Gambusia affinis in uniform and 35 nonuniform flows indicates reasonable prediction of binary outcomes (passage or 36 exclusion) if the flow speed is not near the threshold flow velocity. More research is 37 needed on fish behavior, passage strategies under nonuniform flow regimes and 38 stochastic methods that account for individual differences in swimming performance at or 39 near the threshold flow speed. Future experiments should track and measure ground 40 speeds of ascending fish to test nonuniform flow passage strategies and to improve model 41 predictions. Stochastic models, such as Monte-Carlo techniques, that account for 42 different passage performance among individuals and allow

  1. Radiogenic and Stable Isotope and Hydrogeochemical Investigation of Groundwater, Pajarito Plateau and Surrounding Areas, New Mexico

    SciTech Connect (OSTI)

    Patrick Longmire, Michael Dale, Dale Counce, Andrew Manning, Toti Larson, Kim Granzow, Robert Gray, and Brent Newman

    2007-07-15

    From October 2004 through February 2006, Los Alamos National Laboratory, the New Mexico Environment Department-Department of Energy Oversight Bureau, and the United States Geological Survey conducted a hydrochemical investigation. The purpose of the investigation was to evaluate groundwater flow paths and determine groundwater ages using tritium/helium-3 and carbon-14 along with aqueous inorganic chemistry. Knowledge of groundwater age and flow paths provides a technical basis for selecting wells and springs for monitoring. Groundwater dating is also relevant to groundwater resource management, including aquifer sustainability, especially during periods of long-term drought. At Los Alamos, New Mexico, groundwater is either modern (post-1943), submodern (pre-1943), or mixed (containing both pre- and post-1943 components). The regional aquifer primarily consists of submodern groundwater. Mixed-age groundwater results from initial infiltration of surface water, followed by mixing with perched alluvial and intermediate-depth groundwater and the regional aquifer. No groundwater investigation is complete without using tritium/helium-3 and carbon-14 dating methods to quantify amounts of modern, mixed, and/or submodern components present in samples. Computer models of groundwater flow and transport at Los Alamos should be calibrated to groundwater ages for perched intermediate zones and the regional aquifer determined from this investigation. Results of this study clearly demonstrate the occurrence of multiple flow paths and groundwater ages occurring within the Sierra de los Valles, beneath the Pajarito Plateau, and at the White Rock Canyon springs. Localized groundwater recharge occurs within several canyons dissecting the Pajarito Plateau. Perched intermediate-depth groundwater and the regional aquifer beneath Pueblo Canyon, Los Alamos Canyon, Sandia Canyon, Mortandad Canyon, Pajarito Canyon, and Canon de Valle contain a modern component. This modern component consists

  2. Subsurface Multiphase Flow and Multicomponent Reactive Transport Modeling using High-Performance Computing

    SciTech Connect (OSTI)

    Hammond, Glenn E.; Lichtner, Peter C.; Lu, Chuan

    2007-07-16

    Numerical modeling has become a critical tool to the U.S. Department of Energy for evaluating the environmental impact of alternative energy sources and remediation strategies for legacy waste sites. Unfortunately, the physical and chemical complexity of many sites overwhelms the capabilities of even most state of the art groundwater models. Of particular concern are the representation of highly-heterogeneous stratified rock/soil layers in the subsurface and the biological and geochemical interactions of chemical species within multiple fluid phases. Clearly, there is a need for higher-resolution modeling (i.e. more spatial, temporal, and chemical degrees of freedom) and increasingly mechanistic descriptions of subsurface physicochemical processes. We present SciDAC-funded research being performed in the development of PFLOTRAN, a parallel multiphase flow and multicomponent reactive transport model. Written in Fortran90, PFLOTRAN is founded upon PETSc data structures and solvers. We are employing PFLOTRAN in the simulation of uranium transport at the Hanford 300 Area, a contaminated site of major concern to the Department of Energy, the State of Washington, and other government agencies. By leveraging the billions of degrees of freedom available through high-performance computation using tens of thousands of processors, we can better characterize the release of uranium into groundwater and its subsequent transport to the Columbia River, and thereby better understand and evaluate the effectiveness of various proposed remediation strategies.

  3. Liquid-fluidized-bed heat exchanger flow distribution models...

    Office of Scientific and Technical Information (OSTI)

    One contains a horizontal bundle and the other a vertical tube bundle. Plexiglass construction allowed visual observation of flow patterns. The vertical model proved to have more ...

  4. Monitoring and Modeling Fluid Flow in a Developing Enhanced Geothermal...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Enhanced Geothermal System (EGS) Reservoir; 2010 Geothermal Technology Program Peer Review Report Monitoring and Modeling Fluid Flow in a Developing Enhanced Geothermal System ...

  5. Double Shock Experiments and Reactive Flow Modeling of High Pressure...

    Office of Scientific and Technical Information (OSTI)

    Double Shock Experiments and Reactive Flow Modeling of High Pressure LX-17 Detonation Reaction Product States Citation Details In-Document Search Title: Double Shock Experiments ...

  6. Systematic Method for Evaluating Extraction and Injection Flow Rates for 100-KR-4 and 100-HR-3 Groundwater Operable Unit Pump-and-Treat Interim Actions for Hydraulic Containment

    SciTech Connect (OSTI)

    Spiliotopoulos, Alexandros A.

    2013-03-20

    This document describes a systematic method to develop flow rate recommendations for Pump-and-Treat (P&T) extraction and injection wells in 100-KR-4 and 100-HR-3 Groundwater Operable Units (OU) of the Hanford Site. Flow rate recommendations are developed as part of ongoing performance monitoring and remedy optimization of the P&T interim actions to develop hydraulic contairnnent of the dissolved chromium plume in groundwater and protect the Columbia River from further discharges of groundwater from inland. This document details the methodology and data required to infer the influence of individual wells near the shoreline on hydraulic containment and river protection and develop flow rate recommendations to improve system performance and mitigate potential shortcomings of the system configuration in place.

  7. Electrochemical Model of the Fe/V Redox Flow Battery

    SciTech Connect (OSTI)

    Stephenson, David E.; Kim, Soowhan; Chen, Feng; Thomsen, Edwin C.; Viswanathan, Vilayanur V.; Wang, Wei; Sprenkle, Vincent L.

    2012-11-05

    This paper presents a mathematical model for the new Fe/V redox flow battery chemistry. The model is designed to be useful for stack development and cost analysis purposes.

  8. Solyndra Facts vs. Fiction: Cash Flow Modeling

    Broader source: Energy.gov [DOE]

    Questions have been raised about a quote selectively pulled from an Aug. 20, 2009 email to make it look like Solyndra would run out of cash by Sept. 2011. To be clear, the analysis addressed in that email did not refer to Solyndra’s corporate cash flow, but rather the cash flow for a subsidiary of Solyndra – the “Fab 2 Project Company.

  9. Hanford Site ground-water monitoring for 1994

    SciTech Connect (OSTI)

    Dresel, P.E.; Thorne, P.D.; Luttrell, S.P.

    1995-08-01

    This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1994 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiologic and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1994 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1993 and June 1994. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal.

  10. Two-phase flow modeling with discrete particles

    SciTech Connect (OSTI)

    Mortensen, G.A.; Trapp, J.A. |

    1992-03-23

    The design of efficient heat exchangers in which the working fluid changes phase requires accurate modeling of two-phase fluid flow. The local Navier-Stokes equations form the basic continuum equations for this flow situation. However, the local instantaneous model using these equations is intractable for afl but the simplest problems. AH the practical models for two-phase flow analysis are based on equations that have been averaged over control volumes. These models average out the detailed description within the control volumes and rely on flow regime maps to determine the distribution of the two phases within a control volume. Flow regime maps depend on steady state models and probably are not correct for dynamic models. Numerical simulations of the averaged two-phase flow models are usually performed using a two-fluid Eulerian description for the two phases. Eulerian descriptions have the advantage of having simple boundary conditions, but the disadvantage of introducing numerical diffusion, i.e., sharp interfaces are not maintained as the flow develops, but are diffused. Lagrangian descriptions have the advantage of being able to track sharp interfaces without diffusion, but they have the disadvantage of requiring more complicated boundary conditions. This paper describes a numerical scheme and attendant computer program, DISCON2, for the calculation of two-phase flows that does not require the use of flow regime maps. This model is intermediate between the intractable local instantaneous and the averaged two-fluid model. This new model uses a combination of an Eulerian and a Lagrangian representation of the two phases. The dispersed particles (bubbles or drops) are modeled individually using a large representative number of particles, each with their own Lagrangian description. The continuous phases (liquid or gas) use an Eulerian description.

  11. Processes, mechanisms, parameters, and modeling approaches for partially saturated flow in soil and rock media; Yucca Mountain Site Characterization Project

    SciTech Connect (OSTI)

    Wang, J.S.Y.; Narasimhan, T.N.

    1993-06-01

    This report discusses conceptual models and mathematical equations, analyzes distributions and correlations among hydrological parameters of soils and tuff, introduces new path integration approaches, and outlines scaling procedures to model potential-driven fluid flow in heterogeneous media. To properly model the transition from fracture-dominated flow under saturated conditions to matrix-dominated flow under partially saturated conditions, characteristic curves and permeability functions for fractures and matrix need to be improved and validated. Couplings from two-phase flow, heat transfer, solute transport, and rock deformation to liquid flow are also important. For stochastic modeling of alternating units of welded and nonwelded tuff or formations bounded by fault zones, correlations and constraints on average values of saturated permeability and air entry scaling factor between different units need to be imposed to avoid unlikely combinations of parameters and predictions. Large-scale simulations require efficient and verifiable numerical algorithms. New path integration approaches based on postulates of minimum work and mass conservation to solve flow geometry and potential distribution simultaneously are introduced. This verifiable integral approach, together with fractal scaling procedures to generate statistical realizations with parameter distribution, correlation, and scaling taken into account, can be used to quantify uncertainties and generate the cumulative distribution function for groundwater travel times.

  12. EPA's groundwater protection strategy

    SciTech Connect (OSTI)

    Smith, J. )

    1992-06-01

    What the EPA, working jointly with the states, hopes to accomplish over the next ten years in order to integrate and coordinate all the groundwater programs within the agency is discussed. Although many other EPA programs such as Superfund, Clean Air Act, and Wetlands Management are often highlighted in the media, EPA does not down rate the importance of groundwater protection. Indeed as a resource, it is one of the most important commodities. Groundwater is the basis for life in this country. Recharge rates are no where near what the withdrawal rates are in many areas of the country. Twenty-five percent of all the potable water comes from groundwater. Groundwater supplies 50 percent of the needs for all the US population. If you include strictly rural areas, it supplies 95 percent of all the use. Something that most people who are not groundwater hydrologists would not think about is the fact that groundwater is a recharge mechanism that provides over 30 percent of the flow in streams and major rivers.

  13. Shallow ground-water flow, water levels, and quality of water, 1980-84, Cowles Unit, Indiana Dunes National Lakeshore

    SciTech Connect (OSTI)

    Cohen, D.A.; Shedlock, R.J.

    1986-01-01

    The Cowles Unit of Indiana Dunes National Lakeshore in Porter County, northwest Indiana, contains a broad dune-beach complex along the southern shoreline of Lake Michigan and a large wetland, called the Great Marsh, that occupies the lowland between the shoreline dunes and an older dune-beach complex farther inland. Water levels and water quality in the surficial aquifer were monitored from 1977 to 1984 near settling ponds on adjacent industrial property at the western end of the Cowles Unit. Since 1980, when the settling pond bottoms were sealed, these intradunal lowlands contained standing water only during periods of high snowmelt or rainfall. Water level declines following the cessation of seepage ranged from 6 feet at the eastern-most settling pond to nearly 14 feet at the western-most pond. No general pattern of water table decline was observed in the Great Marsh or in the shoreline dune complex at distances > 3,000 ft east or north of the settling ponds. Since the settling ponds were sealed, the concentration of boron has decreased while concentrations of cadmium, arsenic, zinc, and molybdenum in shallow ground-water downgradient of the ponds show no definite trends in time. Arsenic, boron and molybdenum have remained at concentrations above those of shallow groundwater in areas unaffected by settling pond seepage. 11 refs., 10 figs., 1 tab.

  14. Fluid Flow Model Development for Representative Geologic Media

    Office of Energy Efficiency and Renewable Energy (EERE)

    Clay and granitic geologic rock units are potential host media for future repositories for used nuclear fuel and high level waste. This report addresses the representation of flow in these two media within numerical process (discrete fracture network) models.

  15. GrndWaterFlow.book

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Section 8.0 Groundwater Flow Model of CAUs 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada 8-10 8.3 Flow Model Sensitivity to Steady-State Temperature Distribution 8.3.1 Introduction The Pahute Mesa CAU flow model spans an area 50 by 53 km with elevations between 3.5 km bmsl to 1.5 km amsl. Within the domain, there are three volcanic caldera complexes and extensive extra-caldera zones as well. Temperatures are not the same everywhere in this model domain. In the flow model,

  16. A Bayesian Modeling Approach for Estimation of a Shape-Free Groundwater Age Distribution using Multiple Tracers

    SciTech Connect (OSTI)

    Massoudieh, Arash; Visser, Ate; Sharifi, Soroosh; Broers, Hans Peter

    2013-10-15

    The mixing of groundwaters with different ages in aquifers, groundwater age is more appropriately represented by a distribution rather than a scalar number. To infer a groundwater age distribution from environmental tracers, a mathematical form is often assumed for the shape of the distribution and the parameters of the mathematical distribution are estimated using deterministic or stochastic inverse methods. We found that the prescription of the mathematical form limits the exploration of the age distribution to the shapes that can be described by the selected distribution. In this paper, the use of freeform histograms as groundwater age distributions is evaluated. A Bayesian Markov Chain Monte Carlo approach is used to estimate the fraction of groundwater in each histogram bin. This method was able to capture the shape of a hypothetical gamma distribution from the concentrations of four age tracers. The number of bins that can be considered in this approach is limited based on the number of tracers available. The histogram method was also tested on tracer data sets from Holten (The Netherlands; 3H, 3He, 85Kr, 39Ar) and the La Selva Biological Station (Costa-Rica; SF 6, CFCs, 3H, 4He and 14C), and compared to a number of mathematical forms. According to standard Bayesian measures of model goodness, the best mathematical distribution performs better than the histogram distributions in terms of the ability to capture the observed tracer data relative to their complexity. Among the histogram distributions, the four bin histogram performs better in most of the cases. The Monte Carlo simulations showed strong correlations in the posterior estimates of bin contributions, indicating that these bins cannot be well constrained using the available age tracers. The fact that mathematical forms overall perform better than the freeform histogram does not undermine the benefit of the

  17. A Bayesian Modeling Approach for Estimation of a Shape-Free Groundwater Age Distribution using Multiple Tracers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Massoudieh, Arash; Visser, Ate; Sharifi, Soroosh; Broers, Hans Peter

    2013-10-15

    The mixing of groundwaters with different ages in aquifers, groundwater age is more appropriately represented by a distribution rather than a scalar number. To infer a groundwater age distribution from environmental tracers, a mathematical form is often assumed for the shape of the distribution and the parameters of the mathematical distribution are estimated using deterministic or stochastic inverse methods. We found that the prescription of the mathematical form limits the exploration of the age distribution to the shapes that can be described by the selected distribution. In this paper, the use of freeform histograms as groundwater age distributions is evaluated.more » A Bayesian Markov Chain Monte Carlo approach is used to estimate the fraction of groundwater in each histogram bin. This method was able to capture the shape of a hypothetical gamma distribution from the concentrations of four age tracers. The number of bins that can be considered in this approach is limited based on the number of tracers available. The histogram method was also tested on tracer data sets from Holten (The Netherlands; 3H, 3He, 85Kr, 39Ar) and the La Selva Biological Station (Costa-Rica; SF 6, CFCs, 3H, 4He and 14C), and compared to a number of mathematical forms. According to standard Bayesian measures of model goodness, the best mathematical distribution performs better than the histogram distributions in terms of the ability to capture the observed tracer data relative to their complexity. Among the histogram distributions, the four bin histogram performs better in most of the cases. The Monte Carlo simulations showed strong correlations in the posterior estimates of bin contributions, indicating that these bins cannot be well constrained using the available age tracers. The fact that mathematical forms overall perform better than the freeform histogram does not undermine the benefit of the freeform approach, especially for the cases where a larger amount of observed data is

  18. Modeling of Time Varying Slag Flow in Coal Gasifiers

    SciTech Connect (OSTI)

    Pilli, Siva Prasad; Johnson, Kenneth I.; Williford, Ralph E.; Sundaram, S. K.; Korolev, Vladimir N.; Crum, Jarrod V.

    2008-08-30

    There is considerable interest within government agencies and the energy industries across the globe to further advance the clean and economical conversion of coal into liquid fuels to reduce our dependency on imported oil. To date, advances in these areas have been largely based on experimental work. Although there are some detailed systems level performance models, little work has been done on numerical modeling of the component level processes. If accurate models are developed, then significant R&D time might be saved, new insights into the process might be gained, and some good predictions of process or performance can be made. One such area is the characterization of slag deposition and flow on the gasifier walls. Understanding slag rheology and slag-refractory interactions is critical to design and operation of gasifiers with extended refractory lifetimes and also to better control of operating parameters so that the overall gasifier performance with extended service life can be optimized. In the present work, the literature on slag flow modeling was reviewed and a model similar to Seggiani’s was developed to simulate the time varying slag accumulation and flow on the walls of a Prenflo coal gasifier. This model was further extended and modified to simulate a refractory wall gasifier including heat transfer through the refractory wall with flowing slag in contact with the refractory. The model was used to simulate temperature dependent slag flow using rheology data from our experimental slag testing program. These modeling results as well as experimental validation are presented.

  19. Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    in EGS Reservoirs; II: Full-Waveform Inversion of 3D-9C VSP data from Bradys EGS Site and Update of the Brady Reservoir Scale Model | Department of Energy Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs; II: Full-Waveform Inversion of 3D-9C VSP data from Bradys EGS Site and Update of the Brady Reservoir Scale Model Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs; II: Full-Waveform Inversion of 3D-9C

  20. Implementation of ORR Groundwater Strategy

    Office of Environmental Management (EM)

    ... modeling * Summary of progress in annual Remediation Effectiveness Report Groundwater Program ... * first sampling event in FY 2015 Q2 was successfully completed ...

  1. A preliminary study to Assess Model Uncertainties in Fluid Flows

    SciTech Connect (OSTI)

    Marc Oliver Delchini; Jean C. Ragusa

    2009-09-01

    The goal of this study is to assess the impact of various flow models for a simplified primary coolant loop of a light water nuclear reactor. The various fluid flow models are based on the Euler equations with an additional friction term, gravity term, momentum source, and energy source. The geometric model is purposefully chosen simple and consists of a one-dimensional (1D) loop system in order to focus the study on the validity of various fluid flow approximations. The 1D loop system is represented by a rectangle; the fluid is heated up along one of the vertical legs and cooled down along the opposite leg. A pressurizer and a pump are included in the horizontal legs. The amount of energy transferred and removed from the system is equal in absolute value along the two vertical legs. The various fluid flow approximations are compressible vs. incompressible, and complete momentum equation vs. Darcys approximation. The ultimate goal is to compute the fluid flow models uncertainties and, if possible, to generate validity ranges for these models when applied to reactor analysis. We also limit this study to single phase flows with low-Mach numbers. As a result, sound waves carry a very small amount of energy in this particular case. A standard finite volume method is used for the spatial discretization of the system.

  2. Modelling of multiphase flow in ironmaking blast furnace

    SciTech Connect (OSTI)

    Dong, X.F.; Yu, A.B.; Burgess, J.M.; Pinson, D.; Chew, S.; Zulli, P.

    2009-01-15

    A mathematical model for the four-phase (gas, powder, liquid, and solids) flow in a two-dimensional ironmaking blast furnace is presented by extending the existing two-fluid flow models. The model describes the motion of gas, solid, and powder phases, based on the continuum approach, and implements the so-called force balance model for the flow of liquids, such as metal and slag in a blast furnace. The model results demonstrate a solid stagnant zone and dense powder hold-up region, as well as a dense liquid flow region that exists in the lower part of a blast furnace, which are consistent with the experimental observations reported in the literature. The simulation is extended to investigate the effects of packing properties and operational conditions on the flow and the volume fraction distribution of each phase in a blast furnace. It is found that solid movement has a significant effect on powder holdup distribution. Small solid particles and low porosity distribution are predicted to affect the fluid flow considerably, and this can cause deterioration in bed permeability. The dynamic powder holdup in a furnace increases significantly with the increase of powder diameter. The findings should be useful to better understand and control blast furnace operations.

  3. Groundwater geochemical modeling and simulation of a breached high-level radioactive waste repository in the northern Tularosa Basin, New Mexico

    SciTech Connect (OSTI)

    Chappell, R.W.

    1989-01-01

    The northern Tularosa Basin in south-central New Mexico was ranked favorably as a potential location for a high-level radioactive waste repository by a US Geological Survey pilot screening study of the Basin and Range Province. The favorable ranking was based chiefly on hydrogeologic and descriptive geochemical evidence. A goal of this study was to develop a methodology for predicting the performance of this or any other basin as a potential repository site using geochemical methods. The approach involves first characterizing the groundwater geochemistry, both chemically and isotopically, and reconstructing the probable evolutionary history of, and controls on the ground water chemistry through modeling. In the second phase of the approach, a hypothetically breached repository is introduced into the system, and the mobility of the parent radionuclide, uranium, in the groundwater is predicted. Possible retardation of uranium transport in the downgradient flow direction from the repository by adsorption and mineral precipitation is then considered. The Permian Yeso Formation, the primary aquifer in the northern Tularosa Basin, was selected for study, development and testing of the methodology outlined above. The Yeso Formation contains abundant gypsum and related evaporite minerals, which impart a distinctive chemical signature to the ground water. Ground water data and solubility calculations indicate a conceptual model of irreversible gypsum and dolomite dissolution with concomitant calcite precipitation. Recharge areas are apparent from temperature, {delta}{sup 18}O and {delta}{sup 2} H, and {sup 3}H trends in the aquifer. Corrected {sup 14}C ages range between modern and 31,200 years, and suggest an average ground water velocity of 0.83 m/yr.

  4. Hanford Site groundwater monitoring for fiscal year 1996

    SciTech Connect (OSTI)

    Hartman, M.J.; Dresel, P.E.; Borghese, J.V.

    1997-02-01

    This report presents the results of groundwater and vadose-zone monitoring for fiscal year (FY) 1996 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that affected groundwater quality on the site. Characterization and monitoring of the vadose zone during FY 1996 comprised primarily spectral gamma logging, soil-gas monitoring, and electrical resistivity tomography. Water-level monitoring was performed to evaluate groundwater-flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Water levels over most of the Hanford Site continued to decline between June 1995 and June 1996. Groundwater chemistry was monitored to track the extent of contamination, to note trends, and to identify emerging groundwater-quality problems. The most widespread radiological contaminant plumes were tritium and iodine-129. Smaller plumes of strontium-90, technetium-99, and plutonium also were present at levels above the U.S. Environmental Protection Agency or State of Washington interim drinking water standards. Uranium concentrations greater than the proposed drinking water standard were also observed. Nitrate, fluoride, chromium, carbon tetrachloride, chloroform, trichloroethylene, and cis-1,2-dichlomethylene were present in groundwater samples at levels above their U.S. Environmental Protection Agency or State of Washington maximum contaminant levels. The nitrate plume is the most extensive. Three-dimensional, numerical, groundwater models were applied to the Hanford Site to predict contaminant-flow paths and the impact of operational changes on site groundwater conditions. Other models were applied to assess the performance of three separate pump-and-treat systems.

  5. Modeling Fluid Flow in Natural Systems, Model Validation and Demonstration

    Office of Energy Efficiency and Renewable Energy (EERE)

    Clay and granitic units are potential host media for future repositories for used nuclear fuel. The report addresses the representation and characterization of flow in these two media within...

  6. Cost and Performance Model for Redox Flow Batteries

    SciTech Connect (OSTI)

    Viswanathan, Vilayanur V.; Crawford, Aladsair J.; Stephenson, David E.; Kim, Soowhan; Wang, Wei; Li, Bin; Coffey, Greg W.; Thomsen, Edwin C.; Graff, Gordon L.; Balducci, Patrick J.; Kintner-Meyer, Michael CW; Sprenkle, Vincent L.

    2014-02-01

    A cost model was developed for all vanadium and iron-vanadium redox flow batteries. Electrochemical performance modeling was done to estimate stack performance at various power densities as a function of state of charge. This was supplemented with a shunt current model and a pumping loss model to estimate actual system efficiency. The operating parameters such as power density, flow rates and design parameters such as electrode aspect ratio, electrolyte flow channel dimensions were adjusted to maximize efficiency and minimize capital costs. Detailed cost estimates were obtained from various vendors to calculate cost estimates for present, realistic and optimistic scenarios. The main drivers for cost reduction for various chemistries were identified as a function of the energy to power ratio of the storage system. Levelized cost analysis further guided suitability of various chemistries for different applications.

  7. Wetting and free surface flow modeling for potting and encapsulation.

    SciTech Connect (OSTI)

    Brooks, Carlton, F.; Brooks, Michael J.; Graham, Alan Lyman; Noble, David F. ); Notz, Patrick K.; Hopkins, Matthew Morgan; Castaneda, Jaime N.; Mahoney, Leo James; Baer, Thomas A.; Berchtold, Kathryn; Adolf, Douglas Brian; Wilkes, Edward Dean; Rao, Rekha Ranjana; Givler, Richard C.; Sun, Amy Cha-Tien; Cote, Raymond O.; Mondy, Lisa Ann; Grillet, Anne Mary; Kraynik, Andrew Michael

    2007-06-01

    As part of an effort to reduce costs and improve quality control in encapsulation and potting processes the Technology Initiative Project ''Defect Free Manufacturing and Assembly'' has completed a computational modeling study of flows representative of those seen in these processes. Flow solutions are obtained using a coupled, finite-element-based, numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. In addition, two commercially available codes, ProCAST and MOLDFLOW, are also used on geometries representing encapsulation processes at the Kansas City Plant. Visual observations of the flow in several geometries are recorded in the laboratory and compared to the models. Wetting properties for the materials in these experiments are measured using a unique flowthrough goniometer.

  8. Global nuclear material flow/control model

    SciTech Connect (OSTI)

    Dreicer, J.S.; Rutherford, D.S.; Fasel, P.K.; Riese, J.M.

    1997-10-01

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The nuclear danger can be reduced by a system for global management, protection, control, and accounting as part of an international regime for nuclear materials. The development of an international fissile material management and control regime requires conceptual research supported by an analytical and modeling tool which treats the nuclear fuel cycle as a complete system. The prototype model developed visually represents the fundamental data, information, and capabilities related to the nuclear fuel cycle in a framework supportive of national or an international perspective. This includes an assessment of the global distribution of military and civilian fissile material inventories, a representation of the proliferation pertinent physical processes, facility specific geographic identification, and the capability to estimate resource requirements for the management and control of nuclear material. The model establishes the foundation for evaluating the global production, disposition, and safeguards and security requirements for fissile nuclear material and supports the development of other pertinent algorithmic capabilities necessary to undertake further global nuclear material related studies.

  9. Monitoring and Modeling Fluid Flow in a Developing EGS

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3 Peer Review Insert photo of your choice Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir April 24, 2013 Michael Fehler Massachusetts Institute of Technology Monitoring and Monitoring Fluid Flow This presentation does not contain any proprietary confidential, or otherwise restricted information. Relevance/Impact of Research 2 | US DOE Geothermal Program eere.energy.gov Project Objective Use Chevron's high-quality data from a long-term injection in the Salak geothermal field to

  10. Comparison of Mesomechanical and Continuum Granular Flow Models for Ceramics

    SciTech Connect (OSTI)

    Curran, D. R.

    2006-07-28

    Constitutive models for the shear strength of ceramics undergoing fracture are needed for modeling long rod and shaped-charge jet penetration events in ceramic armor. The ceramic material ahead of the penetrator has been observed to be finely comminuted material that flows around the nose of the eroding penetrator (Shockey et al.). The most-used continuum models are of the Drucker-Prager type with an upper cutoff, or of the Mohr-Coulomb type with strain rate dependence and strain softening. A disadvantage of such models is that they have an unclear connection to the actual microscopic processes of granular flow and comminution. An alternate approach is to use mesomechanical models that describe the dynamics of the granular flow, as well as containing a description of the granular comminution and resultant material softening. However, a disadvantage of the mesomechanical models is that they are computationally more burdensome to apply. In the present paper, we compare the behaviors of a mesomechanical model, FRAGBED2, with the Walker and Johnson-Holmquist continuum models, where the granular material is subjected to simple strain histories under various confining pressures and strain rates. We conclude that the mesomechanical model can provide valuable input to the continuum models, both in interpretation of the continuum models' parameters and in suggesting their range of applicability.

  11. Multiphase Flow Modeling of Biofuel Production Processes

    SciTech Connect (OSTI)

    D. Gaston; D. P. Guillen; J. Tester

    2011-06-01

    As part of the Idaho National Laboratory's (INL's) Secure Energy Initiative, the INL is performing research in areas that are vital to ensuring clean, secure energy supplies for the future. The INL Hybrid Energy Systems Testing (HYTEST) Laboratory is being established to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. HYTEST involves producing liquid fuels in a Hybrid Energy System (HES) by integrating carbon-based (i.e., bio-mass, oil-shale, etc.) with non-carbon based energy sources (i.e., wind energy, hydro, geothermal, nuclear, etc.). Advances in process development, control and modeling are the unifying vision for HES. This paper describes new modeling tools and methodologies to simulate advanced energy processes. Needs are emerging that require advanced computational modeling of multiphase reacting systems in the energy arena, driven by the 2007 Energy Independence and Security Act, which requires production of 36 billion gal/yr of biofuels by 2022, with 21 billion gal of this as advanced biofuels. Advanced biofuels derived from microalgal biomass have the potential to help achieve the 21 billion gal mandate, as well as reduce greenhouse gas emissions. Production of biofuels from microalgae is receiving considerable interest due to their potentially high oil yields (around 600 gal/acre). Microalgae have a high lipid content (up to 50%) and grow 10 to 100 times faster than terrestrial plants. The use of environmentally friendly alternatives to solvents and reagents commonly employed in reaction and phase separation processes is being explored. This is accomplished through the use of hydrothermal technologies, which are chemical and physical transformations in high-temperature (200-600 C), high-pressure (5-40 MPa) liquid or supercritical water. Figure 1 shows a simplified diagram of the production of biofuels from algae. Hydrothermal processing has significant

  12. Numerical modeling of an all vanadium redox flow battery.

    SciTech Connect (OSTI)

    Clausen, Jonathan R.; Brunini, Victor E.; Moffat, Harry K.; Martinez, Mario J.

    2014-01-01

    We develop a capability to simulate reduction-oxidation (redox) flow batteries in the Sierra Multi-Mechanics code base. Specifically, we focus on all-vanadium redox flow batteries; however, the capability is general in implementation and could be adopted to other chemistries. The electrochemical and porous flow models follow those developed in the recent publication by [28]. We review the model implemented in this work and its assumptions, and we show several verification cases including a binary electrolyte, and a battery half-cell. Then, we compare our model implementation with the experimental results shown in [28], with good agreement seen. Next, a sensitivity study is conducted for the major model parameters, which is beneficial in targeting specific features of the redox flow cell for improvement. Lastly, we simulate a three-dimensional version of the flow cell to determine the impact of plenum channels on the performance of the cell. Such channels are frequently seen in experimental designs where the current collector plates are borrowed from fuel cell designs. These designs use a serpentine channel etched into a solid collector plate.

  13. Plastic flow modeling in glassy polymers

    SciTech Connect (OSTI)

    Clements, Brad

    2010-12-13

    developed glassy polymer model. While polymers are well known for their non-equilibrium deviatoric behavior we have found the need for incorporating both equilibrium and non-equilibrium volumetric behavior into our theory. Experimental evidence supporting the notion of non-equilibrium volumetric behavior will be summarized. Our polymer yield model accurately captures the stress plateau, softening and hardening and its yield stress predictions agree well with measured values for several glassy polymers including PMMA, PC, and an epoxy resin. We then apply our theory to plate impact experiments in an attempt to address the questions associated with high rate polymer yield in uniaxial strain configurations.

  14. A connectivity-based modeling approach for representing hysteresis in macroscopic two-phase flow properties

    SciTech Connect (OSTI)

    Cihan, Abdullah; Birkholzer, Jens; Trevisan, Luca; Bianchi, Marco; Zhou, Quanlin; Illangasekare, Tissa

    2014-12-31

    During CO2 injection and storage in deep reservoirs, the injected CO2 enters into an initially brine saturated porous medium, and after the injection stops, natural groundwater flow eventually displaces the injected mobile-phase CO2, leaving behind residual non-wetting fluid. Accurate modeling of two-phase flow processes are needed for predicting fate and transport of injected CO2, evaluating environmental risks and designing more effective storage schemes. The entrapped non-wetting fluid saturation is typically a function of the spatially varying maximum saturation at the end of injection. At the pore-scale, distribution of void sizes and connectivity of void space play a major role for the macroscopic hysteresis behavior and capillary entrapment of wetting and non-wetting fluids. This paper presents development of an approach based on the connectivity of void space for modeling hysteretic capillary pressure-saturation-relative permeability relationships. The new approach uses void-size distribution and a measure of void space connectivity to compute the hysteretic constitutive functions and to predict entrapped fluid phase saturations. Two functions, the drainage connectivity function and the wetting connectivity function, are introduced to characterize connectivity of fluids in void space during drainage and wetting processes. These functions can be estimated through pore-scale simulations in computer-generated porous media or from traditional experimental measurements of primary drainage and main wetting curves. The hysteresis model for saturation-capillary pressure is tested successfully by comparing the model-predicted residual saturation and scanning curves with actual data sets obtained from column experiments found in the literature. A numerical two-phase model simulator with the new hysteresis functions is tested against laboratory experiments conducted in a quasi-two-dimensional flow cell (91.4cm5.6cm61cm

  15. A connectivity-based modeling approach for representing hysteresis in macroscopic two-phase flow properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cihan, Abdullah; Birkholzer, Jens; Trevisan, Luca; Bianchi, Marco; Zhou, Quanlin; Illangasekare, Tissa

    2014-12-31

    During CO2 injection and storage in deep reservoirs, the injected CO2 enters into an initially brine saturated porous medium, and after the injection stops, natural groundwater flow eventually displaces the injected mobile-phase CO2, leaving behind residual non-wetting fluid. Accurate modeling of two-phase flow processes are needed for predicting fate and transport of injected CO2, evaluating environmental risks and designing more effective storage schemes. The entrapped non-wetting fluid saturation is typically a function of the spatially varying maximum saturation at the end of injection. At the pore-scale, distribution of void sizes and connectivity of void space play a major role formore » the macroscopic hysteresis behavior and capillary entrapment of wetting and non-wetting fluids. This paper presents development of an approach based on the connectivity of void space for modeling hysteretic capillary pressure-saturation-relative permeability relationships. The new approach uses void-size distribution and a measure of void space connectivity to compute the hysteretic constitutive functions and to predict entrapped fluid phase saturations. Two functions, the drainage connectivity function and the wetting connectivity function, are introduced to characterize connectivity of fluids in void space during drainage and wetting processes. These functions can be estimated through pore-scale simulations in computer-generated porous media or from traditional experimental measurements of primary drainage and main wetting curves. The hysteresis model for saturation-capillary pressure is tested successfully by comparing the model-predicted residual saturation and scanning curves with actual data sets obtained from column experiments found in the literature. A numerical two-phase model simulator with the new hysteresis functions is tested against laboratory experiments conducted in a quasi-two-dimensional flow cell (91.4cm×5.6cm×61cm), packed with homogeneous and

  16. Hydrogeologic controls on ground-water and contaminant discharge to the Columbia River near the Hanford Townsite

    SciTech Connect (OSTI)

    Luttrell, S.P.; Newcomer, D.R.; Teel, S.S.; Vermeul, V.R.

    1992-11-01

    The purpose of this study is to quantify ground-water and contaminant discharge to the Columbia River in the Hanford Townsite vicinity. The primary objectives of the work are to: describe the hydrogeologic setting and controls on ground-water movement and contaminant discharge to the Columbia River; understand the river/aquifer relationship and its effects on contaminant discharge to the Columbia River; quantify the ground-water and contaminant mass discharge to the Columbia River; and provide data that may be useful for a three-dimensional model of ground-water flow and contaminant transport in the Hanford Townsite study area. The majority of ground-water contamination occurs within the unconfined aquifer; therefore, ground-water and contaminant discharge from the unconfined aquifer is the emphasis of this study. The period of study is primarily from June 1990 through March 1992.

  17. Interfacial shear modeling in two-phase annular flow

    SciTech Connect (OSTI)

    Kumar, R.; Edwards, D.P.

    1996-07-01

    A new interfacial shear stress model called the law of the interface model, based on the law of the wall approach in turbulent flows, has been developed and locally applied in a fully developed, adiabatic, two-phase annular flow in a duct. Numerical results have been obtained using this model in conjunction with other models available in the literature that are required for the closure of the continuity and momentum equations. These results have been compared with droplet velocity data (using laser Doppler velocimetry and hot film anemometry), void fraction data (using gamma densitometry) and pressure drop data obtained in a R-134A refrigerant test facility. Droplet velocity results match the experimental data well, however, the prediction of the void fraction is less accurate. The poor prediction of void fraction, especially for the low void fraction cases, appears to be due to the lack of a good mechanistic model for entrainment.

  18. Theoretical foundation for measuring the groundwater age distribution.

    SciTech Connect (OSTI)

    Gardner, William Payton; Arnold, Bill Walter

    2014-01-01

    In this study, we use PFLOTRAN, a highly scalable, parallel, flow and reactive transport code to simulate the concentrations of 3H, 3He, CFC-11, CFC-12, CFC-113, SF6, 39Ar, 81Kr, 4He and themean groundwater age in heterogeneous fields on grids with an excess of 10 million nodes. We utilize this computational platform to simulate the concentration of multiple tracers in high-resolution, heterogeneous 2-D and 3-D domains, and calculate tracer-derived ages. Tracer-derived ages show systematic biases toward younger ages when the groundwater age distribution contains water older than the maximum tracer age. The deviation of the tracer-derived age distribution from the true groundwater age distribution increases with increasing heterogeneity of the system. However, the effect of heterogeneity is diminished as the mean travel time gets closer the tracer age limit. Age distributions in 3-D domains differ significantly from 2-D domains. 3D simulations show decreased mean age, and less variance in age distribution for identical heterogeneity statistics. High-performance computing allows for investigation of tracer and groundwater age systematics in high-resolution domains, providing a platform for understanding and utilizing environmental tracer and groundwater age information in heterogeneous 3-D systems. Groundwater environmental tracers can provide important constraints for the calibration of groundwater flow models. Direct simulation of environmental tracer concentrations in models has the additional advantage of avoiding assumptions associated with using calculated groundwater age values. This study quantifies model uncertainty reduction resulting from the addition of environmental tracer concentration data. The analysis uses a synthetic heterogeneous aquifer and the calibration of a flow and transport model using the pilot point method. Results indicate a significant reduction in the uncertainty in permeability with the addition of environmental tracer data, relative

  19. MODELING OF THE GROUNDWATER TRANSPORT AROUND A DEEP BOREHOLE NUCLEAR WASTE REPOSITORY

    SciTech Connect (OSTI)

    N. Lubchenko; M. Rodríguez-Buño; E.A. Bates; R. Podgorney; E. Baglietto; J. Buongiorno; M.J. Driscoll

    2015-04-01

    . Preliminary results show that modeling of the borehole array, including the surrounding rock, predicts convective flow in the system with physical velocities of the order of 10-5 km/yr over 105 years. This results in an escape length on the order of kilometers, which is comparable to the repository depth. However, a correct account of the salinity effects reduces convection velocity and escape length of the radionuclides from the repository.

  20. In situ groundwater bioremediation

    SciTech Connect (OSTI)

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  1. Monitoring and Modeling Fluid Flow in a Developing EGS | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy and Modeling Fluid Flow in a Developing EGS Monitoring and Modeling Fluid Flow in a Developing EGS Monitoring and Modeling Fluid Flow in a Developing EGS presentation at the April 2013 peer review meeting held in Denver, Colorado. modeling_fluid_flow_egs_peer2013.pdf (1.35 MB) More Documents & Publications Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir Integration of Noise and Coda Correlation Data into Kinematic and Waveform Inversions

  2. Numerical modeling of the groundwater contaminant transport for the Lake Karachai Area: The methodological approach and the basic two- dimensional regional model

    SciTech Connect (OSTI)

    Petrov, A.V.; Samsonova, L.M.; Vasil`kova, N.A.; Zinin, A.I.; Zinina, G.A. |

    1994-06-01

    Methodological aspects of the numerical modeling of the groundwater contaminant transport for the Lake Karachay area are discussed. Main features of conditions of the task are the high grade of non-uniformity of the aquifer in the fractured rock massif and the high density of the waste solutions, and also the high volume of the input data: both on the part of parameters of the aquifer (number of pump tests) and on the part of observations of functions of processes (long-time observations by the monitoring well grid). The modeling process for constructing the two dimensional regional model is described, and this model is presented as the basic model for subsequent full three-dimensional modeling in sub-areas of interest. Original powerful mathematical apparatus and computer codes for finite-difference numerical modeling are used.

  3. Groundwater Database

    Broader source: Energy.gov [DOE]

    DOE has one of the largest ground water contamination problems and subsequent cleanup responsibilities for a single entity in the world, in terms of the sheer volume of affected groundwater, number...

  4. NNSS Groundwater

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Devils Hole meeting puts focus on NNSS groundwater. See page 8. See page 7. Moniz Confirmed Energy Secretary; Replaces Chu Dr. Ernest Moniz was officially sworn in as the 13th ...

  5. Recent results and persisting problems in modeling flow induced coalescence

    SciTech Connect (OSTI)

    Forteln, I. E-mail: juza@imc.cas.cz; Jza, J. E-mail: juza@imc.cas.cz

    2014-05-15

    The contribution summarizes recent results of description of the flow induced coalescence in immiscible polymer blends and addresses problems that call for which solving. The theory of coalescence based on the switch between equations for matrix drainage between spherical or deformed droplets provides a good agreement with more complicated modeling and available experimental data for probability, P{sub c}, that the collision of droplets will be followed by their fusion. A new equation for description of the matrix drainage between deformed droplets, applicable to the whole range of viscosity ratios, p, of the droplets and matrixes, is proposed. The theory facilitates to consider the effect of the matrix elasticity on coalescence. P{sub c} decreases with the matrix relaxation time but this decrease is not pronounced for relaxation times typical of most commercial polymers. Modeling of the flow induced coalescence in concentrated systems is needed for prediction of the dependence of coalescence rate on volume fraction of droplets. The effect of the droplet anisometry on P{sub c} should be studied for better understanding the coalescence in flow field with high and moderate deformation rates. A reliable description of coalescence in mixing and processing devices requires proper modeling of complex flow fields.

  6. Branch Flow Model: Relaxations and Convexification-Part II

    SciTech Connect (OSTI)

    Farivar, M; Low, SH

    2013-08-01

    We propose a branch flow model for the analysis and optimization of mesh as well as radial networks. The model leads to a new approach to solving optimal power flow (OPF) that consists of two relaxation steps. The first step eliminates the voltage and current angles and the second step approximates the resulting problem by a conic program that can be solved efficiently. For radial networks, we prove that both relaxation steps are always exact, provided there are no upper bounds on loads. For mesh networks, the conic relaxation is always exact but the angle relaxation may not be exact, and we provide a simple way to determine if a relaxed solution is globally optimal. We propose convexification of mesh networks using phase shifters so that OPF for the convexified network can always be solved efficiently for an optimal solution. We prove that convexification requires phase shifters only outside a spanning tree of the network and their placement depends only on network topology, not on power flows, generation, loads, or operating constraints. Part I introduces our branch flow model, explains the two relaxation steps, and proves the conditions for exact relaxation. Part II describes convexification of mesh networks, and presents simulation results.

  7. Branch Flow Model: Relaxations and Convexification-Part I

    SciTech Connect (OSTI)

    Farivar, M; Low, SH

    2013-08-01

    We propose a branch flow model for the analysis and optimization of mesh as well as radial networks. The model leads to a new approach to solving optimal power flow (OPF) that consists of two relaxation steps. The first step eliminates the voltage and current angles and the second step approximates the resulting problem by a conic program that can be solved efficiently. For radial networks, we prove that both relaxation steps are always exact, provided there are no upper bounds on loads. For mesh networks, the conic relaxation is always exact but the angle relaxation may not be exact, and we provide a simple way to determine if a relaxed solution is globally optimal. We propose convexification of mesh networks using phase shifters so that OPF for the convexified network can always be solved efficiently for an optimal solution. We prove that convexification requires phase shifters only outside a spanning tree of the network and their placement depends only on network topology, not on power flows, generation, loads, or operating constraints. Part I introduces our branch flow model, explains the two relaxation steps, and proves the conditions for exact relaxation. Part II describes convexification of mesh networks, and presents simulation results.

  8. groundwater | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater Monitoring at NETL-Albany Ground Water Testing Program NETL is committed to the safety and health of its employees and of nearby residents and to protecting the environment. As part of a DOE environmental protection program, NETL initiated a ground water monitoring program in 2001 with the Oregon Department of Environmental Quality (DEQ) to evaluate the groundwater flowing beneath the Albany, OR facility. Ground water monitoring wells were installed at that time, and periodic samples

  9. An algebraic model for a zinc/bromine flow cell

    SciTech Connect (OSTI)

    Simpson, G.D.; White, R.E. . Dept. of Chemical Engineering)

    1989-08-01

    An algebraic model for a parallel plate, zinc/bromine flow cell is presented and used to predict various performance quantities, which are compared to those predicted by using previously published differential equation models. The results presented compare well with previous work. The model is based on the concept of using well-mixed zones and linear concentration and potential profiles for the diffusion layers and the separator. The Butler-Volmer equation is used for the electro chemical reactions, and the homogeneous reaction between bromine and bromide is included.

  10. Hanford Site ground-water monitoring for 1993

    SciTech Connect (OSTI)

    Dresel, P.E.; Luttrell, S.P.; Evans, J.C.

    1994-09-01

    This report presents the results of the Ground-Water Surveillance Project monitoring for calendar year 1993 on the Hanford Site, Washington. Hanford Site operations from 1943 onward produced large quantities of radiological and chemical waste that have impacted ground-water quality on the Site. Monitoring of water levels and ground-water chemistry is performed to track the extent of contamination and trends in contaminant concentrations. The 1993 monitoring was also designed to identify emerging ground-water quality problems. The information obtained is used to verify compliance with applicable environmental regulations and to evaluate remedial actions. Data from other monitoring and characterization programs were incorporated to provide an integrated assessment of Site ground-water quality. Additional characterization of the Site`s geologic setting and hydrology was performed to support the interpretation of contaminant distributions. Numerical modeling of sitewide ground-water flow also supported the overall project goals. Water-level monitoring was performed to evaluate ground-water flow directions, to track changes in water levels, and to relate such changes to changes in site disposal practices. Water levels over most of the Hanford Site continued to decline between June 1992 and June 1993. The greatest declines occurred in the 200-West Area. These declines are part of the continued response to the cessation of discharge to U Pond and other disposal facilities. The low permeability in this area which enhanced mounding of waste-water discharge has also slowed the response to the reduction of disposal. Water levels remained nearly constant in the vicinity of B Pond, as a result of continued disposal to the pond. Water levels measured from wells in the unconfined aquifer north and east of the Columbia River indicate that the primary source of recharge is irrigation practices.

  11. Monitoring and Modeling Fluid Flow in a Developing Enhanced Geothermal

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    System (EGS) Reservoir; 2010 Geothermal Technology Program Peer Review Report | Department of Energy Enhanced Geothermal System (EGS) Reservoir; 2010 Geothermal Technology Program Peer Review Report Monitoring and Modeling Fluid Flow in a Developing Enhanced Geothermal System (EGS) Reservoir; 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal Technologies Program Peer Review seismic_025_fehler.pdf (195.11 KB) More Documents & Publications Analysis of Geothermal

  12. An Evaluation of Unsaturated Flow Models in an Arid Climate

    SciTech Connect (OSTI)

    Dixon, J.

    1999-12-01

    The objective of this study was to evaluate the effectiveness of two unsaturated flow models in arid regions. The area selected for the study was the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site in Nye County, Nevada. The two models selected for this evaluation were HYDRUS-1D [Simunek et al., 1998] and the SHAW model [Flerchinger and Saxton, 1989]. Approximately 5 years of soil-water and atmospheric data collected from an instrumented weighing lysimeter site near the RWMS were used for building the models with actual initial and boundary conditions representative of the site. Physical processes affecting the site and model performance were explored. Model performance was based on a detailed sensitivity analysis and ultimately on storage comparisons. During the process of developing descriptive model input, procedures for converting hydraulic parameters for each model were explored. In addition, the compilation of atmospheric data collected at the site became a useful tool for developing predictive functions for future studies. The final model results were used to evaluate the capacities of the HYDRUS and SHAW models for predicting soil-moisture movement and variable surface phenomena for bare soil conditions in the arid vadose zone. The development of calibrated models along with the atmospheric and soil data collected at the site provide useful information for predicting future site performance at the RWMS.

  13. Field site investigation: Effect of mine seismicity on groundwater hydrology

    SciTech Connect (OSTI)

    Ofoegbu, G.I.; Hsiung, S.; Chowdhury, A.H.; Philip, J.

    1995-04-01

    The results of a field investigation on the groundwater-hydrologic effect of mining-induced earthquakes are presented in this report. The investigation was conducted at the Lucky Friday Mine, a silver-lead-zinc mine in the Coeur d`Alene Mining District of Idaho. The groundwater pressure in sections of three fracture zones beneath the water table was monitored over a 24-mo period. The fracture zones were accessed through a 360-m-long inclined borehole, drilled from the 5,700 level station of the mine. The magnitude, source location, and associated ground motions of mining-induced seismic events were also monitored during the same period, using an existing seismic instrumentation network for the mine, augmented with additional instruments installed specifically for the project by the center for Nuclear Waste Regulatory Analyses (CNWRA). More than 50 seismic events of Richter magnitude 1.0 or larger occurred during the monitoring period. Several of these events caused the groundwater pressure to increase, whereas a few caused it to decrease. Generally, the groundwater pressure increased as the magnitude of seismic event increased; for an event of a given magnitude, the groundwater pressure increased by a smaller amount as the distance of the observation point from the source of the event increased. The data was examined using regression analysis. Based on these results, it is suggested that the effect of earthquakes on groundwater flow may be better understood through mechanistic modeling. The mechanical processes and material behavior that would need to be incorporated in such a model are examined. They include a description of the effect of stress change on the permeability and water storage capacity of a fracture rock mass; transient fluid flow; and the generation and transmission of seismic waves through the rock mass.

  14. Groundwater Modeling System Linkage with the Framework for Risk Analysis in Multimedia Environmental Systems

    SciTech Connect (OSTI)

    Whelan, Gene; Castleton, Karl J.

    2006-02-13

    The information in this document summarizes the approach that is used to link FRAMES-2 with GMS. This linkage will provide the user with the ability to (1) send information to a specific model in GMS, thereby modifying the models input information, as allowed by the model developer, (2) run the executable of the numerical model contained in GMS, and (3) extract, from the appropriate GMS output, information required for consumption by downstream models, which are also linked with FRAMES-2.

  15. Finite element model to predict the flow of underground contaminants due to leakage of chemical and/or radio active material from a buried containment. Final technical report

    SciTech Connect (OSTI)

    Anand, S.C.; Pandit, A.

    1983-06-01

    In the investigation, a Galerkin finite element model in two dimensions is developed to study the phenomena of mass transfer in porous media. In particular, the problems of the saltwater encroachment in coastal aquifers and the transport of hazardous wastes in groundwater environment are studied for a wide range of aquifer parameters. The coupled governing partial differential equations are nondimensionalized and solved for a two-dimensional, saturated aquifer in the vertical plane for both steady state and transient conditions using an iterative solution procedure. The flow transport is represented either in terms of the stream function or the freshwater hydraulic head.

  16. Groundwater in the Regional Aquifer

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater in the Regional Aquifer Groundwater in the Regional Aquifer LANL maintains an extensive groundwater monitoring and surveillance program through sampling. August 1, 2013 Conceptual model of water movement and geology at Los Alamos National Laboratory Conceptual model of water movement and geology at Los Alamos National Laboratory RELATED IMAGES http://farm4.staticflickr.com/3749/9827580556_473a91fd78_t.jpg Enlarge http://farm3.staticflickr.com/2856/9804364405_b25f74cbb2_t.jpg En

  17. Numerical modeling of immiscible two-phase flow in micro-models using a commercial CFD code

    SciTech Connect (OSTI)

    Crandall, Dustin; Ahmadia, Goodarz; Smith, Duane H.

    2009-01-01

    Off-the-shelf CFD software is being used to analyze everything from flow over airplanes to lab-on-a-chip designs. So, how accurately can two-phase immiscible flow be modeled flowing through some small-scale models of porous media? We evaluate the capability of the CFD code FLUENT{trademark} to model immiscible flow in micro-scale, bench-top stereolithography models. By comparing the flow results to experimental models we show that accurate 3D modeling is possible.

  18. GrndWaterFlow.book

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater Flow Model of CAUs 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada Appendix A A-59 Table A.11-3 CPU Times in Minutes for FEHM Test Problem Simulations Model Faults Radionuclides Source Location Matrix Diffusion Simulation Time (Yrs) CPU Time (min) Flow No - - - - 19 Flow Yes - - - - 15 F-E Transport No Tritium SCOTCH/SERENA* No 200 71 F-E Transport No Tritium SCOTCH CHVTA** No 200 82 F-E Transport Yes Tritium SCOTCH/SERENA No 200 77 F-E Transport Yes Tritium SCOTCH

  19. A generic model for transport in turbulent shear flows

    SciTech Connect (OSTI)

    Newton, Andrew P. L.; Kim, Eun-Jin [Department of Applied Mathematics, University of Sheffield, Sheffield, S3 7RH (United Kingdom)

    2011-05-15

    Turbulence regulation by large-scale shear flows is crucial for a predictive modeling of transport in plasma. In this paper the suppression of turbulent transport by large-scale flows is studied numerically by measuring the turbulent diffusion D{sub t} and scalar amplitude of decaying passive scalar fields n{sup '} advected by various turbulent flows. Both uniform flows and shear flows are shown to suppress turbulence causing the quenching in transport and turbulence amplitude. The uniform flows U{sub 0}={Lambda}y with the advection rate {Lambda} in the case of a finite correlated forcing with {tau}{sub F}=1 gives rise to the advection/sweeping effect which suppresses D{sub t}, and as {proportional_to}{Lambda}{sup -2} for {Lambda}>>{tau}{sub F}{sup -1}. In contrast, no influence of the uniform flow is found in the case of a short correlated forcing {tau}{sub F}{yields}0 due to Galilean invariance. For the shear flow U{sub 0}={Omega}sinxy ({Omega}= constant shearing rate) with the appropriate choice of the forcing ({tau}{sub F}{yields}0) the nature of transport suppression is shown to crucially depend on the properties of the turbulence. Specifically, for prescribed turbulence with a short correlation time {tau}{sub c}={tau}{sub F}<<{Omega}{sup -1}, the turbulence statistics scale as D{sub t{proportional_to}{Omega}}{sup -0.02}, {proportional_to}{Omega}{sup -0.62} and cross-phase cos{theta}{proportional_to}{Omega}{sup 0.29}. For consistently evolved turbulence with a finite correlation time {tau}{sub c{>=}{Omega}}{sup -1}, turbulence statistics are suppressed more strongly as D{sub t{proportional_to}{Omega}}{sup -1.75}, {proportional_to}{Omega}{sup -2.41}, {proportional_to}{Omega}{sup -0.65} and <{omega}{sup '2}>{proportional_to}{Omega}{sup -0.50}. A novel renormalization scheme is then introduced to rescale our results into the regime within which the kinetic energy and enstrophy are unchanged by

  20. Numerical simulation of ground-water flow in the Culebra dolomite at the Waste Isolation Pilot Plant (WIPP) site: Second interim report

    SciTech Connect (OSTI)

    LaVenue, A.M.; Haug, A.; Kelley, V.A.

    1988-03-01

    This hydrogeologic modeling study has been performed as part of the regional hydrologic characterization of the Waste Isolation Pilot Plant (WIPP) Site in southeastern New Mexico. The study resulted in an estimation of the transmissivity distrubution, hydraulic potentials, flow field, and fluid densities in the Culebra Dolomite Member of the Permian Rustler Formation at the WIPP site. The three-dimensional finite-difference code SWIFT-II was employed for the numerical modeling, using variable-fluid-density and a single-porosity formulation. The modeled area includes and extends beyond the WIPP controlled zone (Zone 3). The work performed consisted of modeling the hydrogeology of the Culebra using two approaches: (1) steady-state modeling to develop the best estimate of the undisturbed head distribution, i.e., of the situation before sinking if the WIPP shafts, which began in 1981; and (2) superimposed transient modeling of local hydrologic responses to excavation of the three WIPP shafts at the center of the WIPP site, as well as to various well tests. Boundary conditions (prescribed constant fluid pressures and densities) were estimated using hydraulic-head and fluid-density data obtained from about 40 wells at and near the WIPP site. The transient modeling used the calculated steady-state freshwater heads as initial conditions. 107 refs., 112 figs., 22 tabs.

  1. Engineered Barrier System Degradation, Flow, and Transport Process Model Report

    SciTech Connect (OSTI)

    E.L. Hardin

    2000-07-17

    The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II).

  2. Modeling two-fluid-phase flow and species transport in porous...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Modeling two-fluid-phase flow and species transport in porous media This content will become publicly available on March 3, 2017 Title: Modeling ...

  3. CFD modeling of entrained-flow coal gasifiers with improved physical and chemical sub-models

    SciTech Connect (OSTI)

    Ma, J.; Zitney, S.

    2012-01-01

    Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. While the turbulent multiphase reacting flow inside entrained-flow gasifiers has been modeled through computational fluid dynamic (CFD), the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented here include a moisture vaporization model with consideration of high mass transfer rate, a coal devolatilization model with more species to represent coal volatiles and heating rate effect on volatile yield, and careful selection of global gas phase reaction kinetics. The enhanced CFD model is applied to simulate two typical oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for systemwide design and optimization.

  4. Evapotranspiration Dynamics and Effects on Groundwater Recharge...

    Office of Scientific and Technical Information (OSTI)

    Prepared for U.S. DEPARTMENT OF ENERGY Legacy Management This page intentionally ... Tuba City UMTRCA site..... 11 Figure 3. Green LAI within the Tuba City groundwater model ...

  5. Transport and Retention of Engineered Nanoporous Particles in Porous Media: Effects of Concentration and Flow Dynamics

    SciTech Connect (OSTI)

    Shang, Jianying; Liu, Chongxuan; Wang, Zheming

    2013-01-20

    Engineered nanoporous particles are an important class of nano-structured materials that can be functionalized in their internal surfaces for various applications including groundwater contaminant sequestration. This paper reported a study of transport and retention of engineered nanoporous silicate particles (ENSPs) that are designed for treatment and remediation of contaminants such as uranium in groundwater and sediments. The transport and retention of ENSPs were investigated under variable particle concentrations and dynamic flow conditions in a synthetic groundwater that mimics field groundwater chemical composition. The dynamic flow condition was achieved using a flow-interruption (stop-flow) approach with variable stop-flow durations to explore particle retention and release kinetics. The results showed that the ENSPs transport was strongly affected by the particle concentrations and dynamic flow conditions. A lower injected ENSPs concentration and longer stop-flow duration led to a more particle retention. The experimental data were used to evaluate the applicability of various kinetic models that were developed for colloidal particle retention and release in describing ENSPs transport. Model fits suggested that the transport and retention of ENSPs were subjected to a complex coupling of reversible attachment/detachment and straining/liberation processes. Both experimental and modeling results indicated that dynamic groundwater flow condition is an important parameter to be considered in exploring and modeling engineered particle transport in subsurface porous media.

  6. Microsoft Word - NRAP-TRS-III-00X-2016_No-Impact Threshold Values for Groundwater Reduced-Order Models.final.2016.docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    No-Impact Threshold Values for Groundwater Reduced-Order Models 28 January 2016 Office of Fossil Energy NRAP-TRS-III-002-2016 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus,

  7. Modeling flow in a pressure-sensitive, heterogeneous medium

    SciTech Connect (OSTI)

    Vasco, Donald W.; Minkoff, Susan E.

    2009-06-01

    Using an asymptotic methodology, including an expansion in inverse powers of {radical}{omega}, where {omega} is the frequency, we derive a solution for flow in a medium with pressure dependent properties. The solution is valid for a heterogeneous medium with smoothly varying properties. That is, the scale length of the heterogeneity must be significantly larger then the scale length over which the pressure increases from it initial value to its peak value. The resulting asymptotic expression is similar in form to the solution for pressure in a medium in which the flow properties are not functions of pressure. Both the expression for pseudo-phase, which is related to the 'travel time' of the transient pressure disturbance, and the expression for pressure amplitude contain modifications due to the pressure dependence of the medium. We apply the method to synthetic and observed pressure variations in a deforming medium. In the synthetic test we model one-dimensional propagation in a pressure-dependent medium. Comparisons with both an analytic self-similar solution and the results of a numerical simulation indicate general agreement. Furthermore, we are able to match pressure variations observed during a pulse test at the Coaraze Laboratory site in France.

  8. FRAMES-2.0 Software System: Linking to the Groundwater Modeling System (GMS) RT3D and MT3DMS Models

    SciTech Connect (OSTI)

    Whelan, Gene; Castleton, Karl J.; Pelton, Mitch A.

    2007-08-08

    Linkages to the Groundwater Modeling System have been developed at Pacific Northwest National Laboratory to enable the Nuclear Regulatory Commission (NRC) to more realistically assess the risk to the public of radioactive contaminants at NRC-licensed sites. Common software tools presently in use are limited in that they cannot assess contaminant migration through complex natural environments. The purpose of this initiative is to provide NRC with a licensing safety-analysis tool with sufficient power, flexibility, and utility that it can serve as the primary software platform for analyzing the hazards associated with licensing actions at those complex sites at which the traditional tools are inappropriate. As a tool designed to realistically approximate prospective doses to the public, this initiative addresses NRCs safety-performance goal by confirming that licensing actions do not result in undue risk to the public.

  9. MSET modeling of Crystal River-3 venturi flow meters.

    SciTech Connect (OSTI)

    Bockhorst, F. K.; Gross, K. C.; Herzog, J. P.; Wegerich, S. W.

    1998-01-05

    The analysis of archived Crystal River-3 feedwater flow data reveals a slow and steady degradation of the flow meter measurements during the 1992/1993 operating cycle. MSET can reliably estimate the true flow rate and quantify the degree of departure between the indicated signal and the true flow rate with high accuracy. The MSET computed flow rate could, in principle, be used to provide an improved estimate of the reactor power and hence avoid the revenue loss associated with derating the reactor based on a faulty feedwater flow rate indication.

  10. Predictions of bubbly flows in vertical pipes using two-fluid models in CFDS-FLOW3D code

    SciTech Connect (OSTI)

    Banas, A.O.; Carver, M.B.; Unrau, D.

    1995-09-01

    This paper reports the results of a preliminary study exploring the performance of two sets of two-fluid closure relationships applied to the simulation of turbulent air-water bubbly upflows through vertical pipes. Predictions obtained with the default CFDS-FLOW3D model for dispersed flows were compared with the predictions of a new model (based on the work of Lee), and with the experimental data of Liu. The new model, implemented in the CFDS-FLOW3D code, included additional source terms in the {open_quotes}standard{close_quotes} {kappa}-{epsilon} transport equations for the liquid phase, as well as modified model coefficients and wall functions. All simulations were carried out in a 2-D axisymmetric format, collapsing the general multifluid framework of CFDS-FLOW3D to the two-fluid (air-water) case. The newly implemented model consistently improved predictions of radial-velocity profiles of both phases, but failed to accurately reproduce the experimental phase-distribution data. This shortcoming was traced to the neglect of anisotropic effects in the modelling of liquid-phase turbulence. In this sense, the present investigation should be considered as the first step toward the ultimate goal of developing a theoretically sound and universal CFD-type two-fluid model for bubbly flows in channels.

  11. Energy flow in passive and active 3D cochlear model

    SciTech Connect (OSTI)

    Wang, Yanli; Steele, Charles; Puria, Sunil

    2015-12-31

    Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.

  12. Gas-kinetic unified algorithm for hypersonic flows covering various flow regimes solving Boltzmann model equation in nonequilibrium effect

    SciTech Connect (OSTI)

    Li, Zhihui; Ma, Qiang; Wu, Junlin; Jiang, Xinyu; Zhang, Hanxin

    2014-12-09

    Based on the Gas-Kinetic Unified Algorithm (GKUA) directly solving the Boltzmann model equation, the effect of rotational non-equilibrium is investigated recurring to the kinetic Rykov model with relaxation property of rotational degrees of freedom. The spin movement of diatomic molecule is described by moment of inertia, and the conservation of total angle momentum is taken as a new Boltzmann collision invariant. The molecular velocity distribution function is integrated by the weight factor on the internal energy, and the closed system of two kinetic controlling equations is obtained with inelastic and elastic collisions. The optimization selection technique of discrete velocity ordinate points and numerical quadrature rules for macroscopic flow variables with dynamic updating evolvement are developed to simulate hypersonic flows, and the gas-kinetic numerical scheme is constructed to capture the time evolution of the discretized velocity distribution functions. The gas-kinetic boundary conditions in thermodynamic non-equilibrium and numerical procedures are studied and implemented by directly acting on the velocity distribution function, and then the unified algorithm of Boltzmann model equation involving non-equilibrium effect is presented for the whole range of flow regimes. The hypersonic flows involving non-equilibrium effect are numerically simulated including the inner flows of shock wave structures in nitrogen with different Mach numbers of 1.5-Ma-25, the planar ramp flow with the whole range of Knudsen numbers of 0.0009-Kn-10 and the three-dimensional re-entering flows around tine double-cone body.

  13. Statistical modeling support for calibration of a multiphysics model of subcooled boiling flows

    SciTech Connect (OSTI)

    Bui, A. V.; Dinh, N. T.; Nourgaliev, R. R.; Williams, B. J.

    2013-07-01

    Nuclear reactor system analyses rely on multiple complex models which describe the physics of reactor neutronics, thermal hydraulics, structural mechanics, coolant physico-chemistry, etc. Such coupled multiphysics models require extensive calibration and validation before they can be used in practical system safety study and/or design/technology optimization. This paper presents an application of statistical modeling and Bayesian inference in calibrating an example multiphysics model of subcooled boiling flows which is widely used in reactor thermal hydraulic analysis. The presence of complex coupling of physics in such a model together with the large number of model inputs, parameters and multidimensional outputs poses significant challenge to the model calibration method. However, the method proposed in this work is shown to be able to overcome these difficulties while allowing data (observation) uncertainty and model inadequacy to be taken into consideration. (authors)

  14. A GIS COST MODEL TO ASSESS THE AVAILABILITY OF FRESHWATER, SEAWATER, AND SALINE GROUNDWATER FOR ALGAL BIOFUEL PRODUCTION IN THE UNITED STATES

    SciTech Connect (OSTI)

    Venteris, Erik R.; Skaggs, Richard; Coleman, Andre M.; Wigmosta, Mark S.

    2013-03-15

    A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a limited techno-economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply, and cost models for supplying seawater and saline groundwater. We estimate that combined, within the coterminous US these resources can support production on the order of 9.46E+7 m3 yr-1 (25 billion gallons yr-1) of renewable biodiesel. Achievement of larger targets requires the utilization of less water efficient sites and relatively expensive saline waters. Geographically, water availability is most favorable for the coast of the Gulf of Mexico and Florida peninsula, where evaporation relative to precipitation is moderate and various saline waters are economically available. As a whole, barren and scrub lands of the southwestern US have limited freshwater supplies so accurate assessment of alternative waters is critical.

  15. A simple model of gas flow in a porous powder compact

    SciTech Connect (OSTI)

    Shugard, Andrew D.; Robinson, David B.

    2014-04-01

    This report describes a simple model for ideal gas flow from a vessel through a bed of porous material into another vessel. It assumes constant temperature and uniform porosity. Transport is treated as a combination of viscous and molecular flow, with no inertial contribution (low Reynolds number). This model can be used to fit data to obtain permeability values, determine flow rates, understand the relative contributions of viscous and molecular flow, and verify volume calibrations. It draws upon the Dusty Gas Model and other detailed studies of gas flow through porous media.

  16. OPF incorporating load models maximizing net revenue. [Optimal Power Flow

    SciTech Connect (OSTI)

    Dias, L.G.; El-Hawary, M.E. . Dept. of Electrical Engineering)

    1993-02-01

    Studies of effects of load modeling in optimal power flow studies using minimum cost and minimum loss objective reveal that a main disadvantage of cost minimization is the reduction of the objective via a reduction in the power demand. This inevitably results in lowering the total revenue and in most cases, reducing net revenue as well. An alternative approach for incorporating load models in security-constrained OPF (SCOPF) studies apparently avoids reducing the total power demand for the intact system, but reduces the voltages. A study of the behavior of conventional OPF solutions in the presence of loads not controlled by ULTC's shows that this result in a reducing the total power demand for the intact system. In this paper, the authors propose an objective that avoids the tendency to lower the total power demand, total revenue and net revenue, for OPF neglecting contingencies (normal OPF), as well as for security-constrained OPF. The minimum cost objective is modified by subtracting the total power demand from the total fuel cost. This is equivalent to maximizing the net revenue.

  17. Evaluation of Maximum Radionuclide Groundwater Concentrations for Basement Fill Model. Zion Station Restoration Project

    SciTech Connect (OSTI)

    Sullivan, Terry

    2014-12-02

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Plant in order to establish a new water treatment plant. There is some residual radioactive particles from the plant which need to be brought down to levels so an individual who receives water from the new treatment plant does not receive a radioactive dose in excess of 25 mrem/y⁻¹. The objectives of this report are: (a) To present a simplified conceptual model for release from the buildings with residual subsurface structures that can be used to provide an upper bound on contaminant concentrations in the fill material; (b) Provide maximum water concentrations and the corresponding amount of mass sorbed to the solid fill material that could occur in each building for use in dose assessment calculations; (c) Estimate the maximum concentration in a well located outside of the fill material; and (d) Perform a sensitivity analysis of key parameters.

  18. A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard A.

    2013-01-01

    This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.

  19. Analytical model for transient gas flow in nuclear fuel rods. [PWR; BWR

    SciTech Connect (OSTI)

    Rowe, D.S.; Oehlberg, R.N.

    1981-08-01

    An analytical model for calculating gas flow and pressure inside a nuclear fuel rod is presented. Such a model is required to calculate the pressure loading of cladding during ballooning that could occur for postulated reactor accidents. The mathematical model uses a porous media (permeability) concept to define the resistance to gas flow along the fuel rod. 7 refs.

  20. Toward a new parameterization of hydraulic conductivity in climate models: Simulation of rapid groundwater fluctuations in Northern California

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vrettas, Michail D.; Fung, Inez Y.

    2015-12-31

    Preferential flow through weathered bedrock leads to rapid rise of the water table after the first rainstorms and significant water storage (also known as ‘‘rock moisture’’) in the fractures. We present a new parameterization of hydraulic conductivity that captures the preferential flow and is easy to implement in global climate models. To mimic the naturally varying heterogeneity with depth in the subsurface, the model represents the hydraulic conductivity as a product of the effective saturation and a background hydraulic conductivity Kbkg, drawn from a lognormal distribution. The mean of the background Kbkg decreases monotonically with depth, while its variance reducesmore » with the effective saturation. Model parameters are derived by assimilating into Richards’ equation 6 years of 30 min observations of precipitation (mm) and water table depths (m), from seven wells along a steep hillslope in the Eel River watershed in Northern California. The results show that the observed rapid penetration of precipitation and the fast rise of the water table from the well locations, after the first winter rains, are well captured with the new stochastic approach in contrast to the standard van Genuchten model of hydraulic conductivity, which requires significantly higher levels of saturated soils to produce the same results. ‘‘Rock moisture,’’ the moisture between the soil mantle and the water table, comprises 30% of the moisture because of the great depth of the weathered bedrock layer and could be a potential source of moisture to sustain trees through extended dry periods. Moreover, storage of moisture in the soil mantle is smaller, implying less surface runoff and less evaporation, with the proposed new model.« less

  1. Toward a new parameterization of hydraulic conductivity in climate models: Simulation of rapid groundwater fluctuations in Northern California

    SciTech Connect (OSTI)

    Vrettas, Michail D.; Fung, Inez Y.

    2015-12-31

    Preferential flow through weathered bedrock leads to rapid rise of the water table after the first rainstorms and significant water storage (also known as ‘‘rock moisture’’) in the fractures. We present a new parameterization of hydraulic conductivity that captures the preferential flow and is easy to implement in global climate models. To mimic the naturally varying heterogeneity with depth in the subsurface, the model represents the hydraulic conductivity as a product of the effective saturation and a background hydraulic conductivity Kbkg, drawn from a lognormal distribution. The mean of the background Kbkg decreases monotonically with depth, while its variance reduces with the effective saturation. Model parameters are derived by assimilating into Richards’ equation 6 years of 30 min observations of precipitation (mm) and water table depths (m), from seven wells along a steep hillslope in the Eel River watershed in Northern California. The results show that the observed rapid penetration of precipitation and the fast rise of the water table from the well locations, after the first winter rains, are well captured with the new stochastic approach in contrast to the standard van Genuchten model of hydraulic conductivity, which requires significantly higher levels of saturated soils to produce the same results. ‘‘Rock moisture,’’ the moisture between the soil mantle and the water table, comprises 30% of the moisture because of the great depth of the weathered bedrock layer and could be a potential source of moisture to sustain trees through extended dry periods. Moreover, storage of moisture in the soil mantle is smaller, implying less surface runoff and less evaporation, with the proposed new model.

  2. NNSS Groundwater Program Welcomes Peer Review Team

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    April 18, 2014 NNSS Groundwater Program Welcomes Peer Review Team Recently, an independent peer review team was invited to assess the groundwater characterization program at the Nevada National Security Site (NNSS). This nationally recognized group of experts, from various external organizations, will examine the computer modeling approach developed to better understand how historic underground nuclear testing in Yucca Flat affected the groundwater. From April 7th to 11th, 2014, five peer

  3. Image-based Stokes flow modeling in bulk proppant packs and propped...

    Office of Scientific and Technical Information (OSTI)

    Image-based Stokes flow modeling in bulk proppant packs and propped fractures under high loading stresses Citation Details In-Document Search This content will become publicly ...

  4. Groundwater Monitoring Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater Monitoring Network Groundwater Monitoring Network The network includes 92 natural sources, 102 regional aquifer wells, 41 intermediate-depth wells and springs, and 67 wells in alluvium in canyons. August 1, 2013 Map of LANL's groundwater monitoring network Map of LANL's groundwater monitoring network

  5. COUNTERCURRENT FLOW LIMITATION EXPERIMENTS AND MODELING FOR IMPROVED REACTOR SAFETY

    SciTech Connect (OSTI)

    Vierow, Karen

    2008-09-26

    This project is investigating countercurrent flow and “flooding” phenomena in light water reactor systems to improve reactor safety of current and future reactors. To better understand the occurrence of flooding in the surge line geometry of a PWR, two experimental programs were performed. In the first, a test facility with an acrylic test section provided visual data on flooding for air-water systems in large diameter tubes. This test section also allowed for development of techniques to form an annular liquid film along the inner surface of the “surge line” and other techniques which would be difficult to verify in an opaque test section. Based on experiences in the air-water testing and the improved understanding of flooding phenomena, two series of tests were conducted in a large-diameter, stainless steel test section. Air-water test results and steam-water test results were directly compared to note the effect of condensation. Results indicate that, as for smaller diameter tubes, the flooding phenomena is predominantly driven by the hydrodynamics. Tests with the test sections inclined were attempted but the annular film was easily disrupted. A theoretical model for steam venting from inclined tubes is proposed herein and validated against air-water data. Empirical correlations were proposed for air-water and steam-water data. Methods for developing analytical models of the air-water and steam-water systems are discussed, as is the applicability of the current data to the surge line conditions. This report documents the project results from July 1, 2005 through June 30, 2008.

  6. Modeling, Analysis and Simulation of Multiscale Preferential Flow - 8/05-8/10 - Final Report

    SciTech Connect (OSTI)

    Ralph Showalter; Malgorzata Peszynska

    2012-07-03

    The research agenda of this project are: (1) Modeling of preferential transport from mesoscale to macroscale; (2) Modeling of fast flow in narrow fractures in porous media; (3) Pseudo-parabolic Models of Dynamic Capillary Pressure; (4) Adaptive computational upscaling of flow with inertia from porescale to mesoscale; (5) Adaptive modeling of nonlinear coupled systems; and (6) Adaptive modeling and a-posteriori estimators for coupled systems with heterogeneous data.

  7. Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling using KH-ACT

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Primary Breakup Model & Detailed Chemistry | Department of Energy Nozzle Flow, Spray, Combustion, & Emission Modeling using KH-ACT Primary Breakup Model & Detailed Chemistry Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling using KH-ACT Primary Breakup Model & Detailed Chemistry Poster presented at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. p-13_som.pdf (285.53 KB) More Documents

  8. Groundwater - Hanford Site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Groundwater Richland Operations Office Richland Operations Office River Corridor Central Plateau Groundwater PHOENIX Groundwater Annual Reports Mission Support Newsroom Groundwater Email Email Page | Print Print Page | Text Increase Font Size Decrease Font Size 200WPumpandTreat 200 West Pump and Treat The groundwater treatment project includes a number of injection and extraction wells feeding five pump and treat facilities in the 100 Area near the reactors, as well as a state-of-the-art

  9. Hanford Site ground-water monitoring for July through December 1987

    SciTech Connect (OSTI)

    Evans, J.C.; Dennison, D.I.; Bryce, R.W.; Mitchell, P.J.; Sherwood, D.R.; Krupka, K.M.; Hinman, N.W.; Jacobson, E.A.; Freshley, M.D.

    1988-12-01

    The Pacific Northwest Laboratory monitors ground-water quality at the Hanford Site for the US Department of Energy to assess the impact of Site operations on the environment. Work undertaken between July and December 1987 included monitoring ground-water elevations across the Site, monitoring hazardous chemicals and radionuclides in ground water, geochemical evaluations of unconfined ground-water data, and calibration of ground-water flow and transport models. Water levels continued to rise in areas receiving increased recharge (e.g., beneath B Pond) and decline in areas where the release of water to disposal facilities has been terminated (e.g., U Pond). The major areas of ground-water contamination defined by monitoring activities are (1) carbon tetrachloride in the 200-West Area; (2) cyanide in and north of the 200-East and 200-West Areas; (3) hexavalent chromium contamination in the 100-B, 100-D, 100-F, 100-H, 100-K, and 200-West Areas; (4) chlorinated hydrocarbons in the vicinity of the Central Landfill and 300 Area; (5) uranium in the 100-F, 100-H, 200-West, and 300 Areas; and (6) tritium and nitrate across the Site. The MINTEQ geochemical code was used to identify chemical reactions that may be affecting the concentrations of dissolved hazardous chemicals in the unconfined ground water. Results indicate that many cations are present mainly as dissolved carbonate complexes and that a majority of the ground-water samples are in near equilibrium with carbonate minerals (e.g., calcite, dolomite, otavite).

  10. Radionuclide migration in groundwater at a low-level waste disposal site: a comparison of predictive performance modeling versus field observations

    SciTech Connect (OSTI)

    Robertson, D.E. Myers, D.A.; Bergeron, M.P.; Champ, D.R.; Killey, R.W.D.; Moltyaner, G.L.; Young, J.L.

    1985-08-01

    This paper describes a project which is structured to test the concept of modeling a shallow land low-level waste burial site. The project involves a comparison of the actual observed radionuclide migration in groundwaters at a 30-year-old well-monitored field site with the results of predictive transport modeling. The comparison is being conducted as a cooperative program with the Atomic Energy of Canada Ltd. (AECL) at the low-level waste management area at the Chalk River Nuclear Laboratories, Ontario, Canada. A joint PNL-AECL field inviestigation was conducted in 1983 and 1984 to complement the existing extensive data base on actual radionuclide migration. Predictive transport modeling is currently being conducted for this site; first, as if it were a new location being considered for a low-level waste shallow-land burial site and only minimal information about the site were available, and second, utilizing the extensive data base available for the site. The modeling results will then be compared with the empirical observations to provide insight into the level of effort needed to reasonably predict the spacial and temporal movement of radionuclides in the groundwater enviroment. 8 refs., 5 figs.,

  11. Watershed response and land energy feedbacks under climate change depend upon groundwater.

    SciTech Connect (OSTI)

    Maxwell, R M; Kollet, S J

    2008-06-10

    Human induced climate change will have a significant impact on the hydrologic cycle, creating changes in fresh water resources, land cover, and feedbacks that are difficult to characterize, which makes it an issue of global importance. Previous studies have not included subsurface storage in climate change simulations and feedbacks. A variably-saturated groundwater flow model with integrated overland flow and land surface model processes is used to examine the interplay between coupled water and energy processes under climate change conditions. A case study from the Southern Great Plains (SGP) USA, an important agricultural region that is susceptible to drought, is used as the basis for three scenarios simulations using a modified atmospheric forcing dataset to reflect predicted effects due to human-induced climate change. These scenarios include an increase in the atmospheric temperature and variations in rainfall amount and are compared to the present-day climate case. Changes in shallow soil saturation and groundwater levels are quantified as well as the corresponding energy fluxes at the land surface. Here we show that groundwater and subsurface lateral flow processes are critical in understanding hydrologic response and energy feedbacks to climate change and that certain regions are more susceptible to changes in temperature, while others to changes in precipitation. This groundwater control is critical for understanding recharge and drought processes, possible under future climate conditions.

  12. Modeling two-fluid-phase flow and species transport in porous...

    Office of Scientific and Technical Information (OSTI)

    Modeling two-fluid-phase flow and species transport in porous media Citation Details In-Document Search This content will become publicly available on March 3, 2017 Title: Modeling ...

  13. Flow field computation of the NREL S809 airfoil using various turbulence models

    SciTech Connect (OSTI)

    Chang, Y.L.; Yang, S.L.; Arici, O. [Michigan Technological Univ., Houghton, MI (United States). Mechanical Engineering-Engineering Mechanics Dept.

    1996-10-01

    Performance comparison of three popular turbulence models, namely Baldwin-Lomas algebraic model, Chien`s Low-Reynolds-Number {kappa}-{epsilon} model, and Wilcox`s Low-Reynolds-Number {kappa}-{omega} model, is given. These models were applied to calculate the flow field around the National Renewable Energy Laboratory S809 airfoil using Total Variational Diminishing scheme. Numerical results of C{sub P}, C{sub L}, and C{sub D} are presented along with the Delft experimental data. It is shown that all three models perform well for attached flow, i.e., no flow separation at low angles of attack. However, at high angles of attack with flow separation, convergence characteristics show Wilcox`s model outperforms the other models. Results of this study will be used to guide the authors in their dynamic stall research.

  14. Computational flow modeling of a simplified integrated tractor...

    Office of Scientific and Technical Information (OSTI)

    The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, ...

  15. Microsoft Word - NRAP-TRS-III-002-2014_Second-Generation Reduced-Order Model for Calculation of Groundwater Impacts_20140407.do

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Second-Generation Reduced-Order Model for Calculation of Groundwater Impacts as a Function pH, Total Dissolved Solids, and Trace Metal Concentrations 7 April 2014 Office of Fossil Energy NRAP-TRS-III-002-2014 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility

  16. Hanford Site Groundwater Monitoring for Fiscal Year 2003

    SciTech Connect (OSTI)

    Hartman, Mary J.; Morasch, Launa F.; Webber, William D.

    2004-04-12

    /uranium plumes. ''Resource Conservation and Recovery Act'' groundwater monitoring continued at 24 waste management areas during fiscal year 2003: 15 under interim or final status detection programs and data indicate that they are not adversely affecting groundwater; 7 under interim status groundwater quality assessment programs to assess contamination; and 2 under final status corrective-action programs. During calendar year 2003, drillers completed seven new RCRA monitoring wells, nine wells for CERCLA, and two wells for research on chromate bioremediation. Vadose zone monitoring, characterization, and remediation continued in fiscal year 2003. Remediation and associated monitoring continued at a soil-vapor extraction system in the 200 West Area, which removes gaseous carbon tetrachloride from the vadose zone. Soil vapor also was sampled to locate carbon tetrachloride sites with the potential to impact groundwater in the future. DOE uses geophysical methods to monitor potential movement of contamination beneath single-shell tank farms. During fiscal year 2003, DOE monitored selected boreholes within each of the 12 single-shell tank farms. In general, the contaminated areas appeared to be stable over time. DOE drilled new boreholes at the T Tank Farm to characterize subsurface contamination near former leak sites. The System Assessment Capability is a set of computer modules simulating movement of contaminants from waste sites through the vadose zone and groundwater. In fiscal year 2003, it was updated with the addition of an atmospheric transport module and with newer versions of models including an updated groundwater flow and transport model.

  17. Ground-water geochemistry and radionuclide activity in the Cambrian-Ordovician aquifer of Dodge and Fond du Lac counties, Wisconsin. Technical report

    SciTech Connect (OSTI)

    Weaver, T.R.; Bahr, J.M.; Anderson, M.P.

    1990-01-01

    Analyses of groundwater from wells in the Cambrian-Ordovician aquifer of eastern Wisconsin indicate that regions of the aquifer contain elevated concentrations of dissolved solids, chloride and sulfate. Groundwater from several wells in the area also approach or exceed the current drinking water standard for combined radium activity. Significant changes in groundwater chemistry occur where the aquifer becomes confined by the Maquoketa shale. Concentrations of Cl(-), SO4(2-) and Na(+) increase in the confined region, and the highest combined radium activities are typically observed in the area. Geochemical modeling implies that the observed changes in major ion groundwater chemistry occur in response to the presence of the confining unit which may act as a source of SO4(2-), through gypsum dissolution, and Na(+), through cation exchange. A finite difference groundwater flow model was linked to a particle tracking routine to determine groundwater flow paths and residence times in the aquifer near the boundary between unconfined and confined conditions. Results suggest that the presence of the confining unit produces a vertically stratified flow regime in the confined region.

  18. FACT (Version 2.0) - Subsurface Flow and Contaminant Transport Documentation and User's Guide

    SciTech Connect (OSTI)

    Aleman, S.E.

    2000-05-05

    This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media.

  19. A reaction-based paradigm to model reactive chemical transport in groundwater with general kinetic and equilibrium reactions

    SciTech Connect (OSTI)

    Zhang, Fan; Yeh, Gour-Tsyh; Parker, Jack C; Brooks, Scott C; Pace, Molly; Kim, Young Jin; Jardine, Philip M; Watson, David B

    2007-01-01

    This paper presents a reaction-based water quality transport model in subsurface flow systems. Transport of chemical species with a variety of chemical and physical processes is mathematically described by M partial differential equations (PDEs). Decomposition via Gauss-Jordan column reduction of the reaction network transforms M species reactive transport equations into two sets of equations: a set of thermodynamic equilibrium equations representing NE equilibrium reactions and a set of reactive transport equations of M-NE kinetic-variables involving no equilibrium reactions (a kinetic-variable is a linear combination of species). The elimination of equilibrium reactions from reactive transport equations allows robust and efficient numerical integration. The model solves the PDEs of kinetic-variables rather than individual chemical species, which reduces the number of reactive transport equations and simplifies the reaction terms in the equations. A variety of numerical methods are investigated for solving the coupled transport and reaction equations. Simulation comparisons with exact solutions were performed to verify numerical accuracy and assess the effectiveness of various numerical strategies to deal with different application circumstances. Two validation examples involving simulations of uranium transport in soil columns are presented to evaluate the ability of the model to simulate reactive transport with complex reaction networks involving both kinetic and equilibrium reactions.

  20. Prognostic residual mean flow in an ocean general circulation model and its relation to prognostic Eulerian mean flow

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Saenz, Juan A.; Chen, Qingshan; Ringler, Todd

    2015-05-19

    Recent work has shown that taking the thickness-weighted average (TWA) of the Boussinesq equations in buoyancy coordinates results in exact equations governing the prognostic residual mean flow where eddy–mean flow interactions appear in the horizontal momentum equations as the divergence of the Eliassen–Palm flux tensor (EPFT). It has been proposed that, given the mathematical tractability of the TWA equations, the physical interpretation of the EPFT, and its relation to potential vorticity fluxes, the TWA is an appropriate framework for modeling ocean circulation with parameterized eddies. The authors test the feasibility of this proposition and investigate the connections between the TWAmore » framework and the conventional framework used in models, where Eulerian mean flow prognostic variables are solved for. Using the TWA framework as a starting point, this study explores the well-known connections between vertical transfer of horizontal momentum by eddy form drag and eddy overturning by the bolus velocity, used by Greatbatch and Lamb and Gent and McWilliams to parameterize eddies. After implementing the TWA framework in an ocean general circulation model, we verify our analysis by comparing the flows in an idealized Southern Ocean configuration simulated using the TWA and conventional frameworks with the same mesoscale eddy parameterization.« less

  1. Prognostic residual mean flow in an ocean general circulation model and its relation to prognostic Eulerian mean flow

    SciTech Connect (OSTI)

    Saenz, Juan A.; Chen, Qingshan; Ringler, Todd

    2015-05-19

    Recent work has shown that taking the thickness-weighted average (TWA) of the Boussinesq equations in buoyancy coordinates results in exact equations governing the prognostic residual mean flow where eddy–mean flow interactions appear in the horizontal momentum equations as the divergence of the Eliassen–Palm flux tensor (EPFT). It has been proposed that, given the mathematical tractability of the TWA equations, the physical interpretation of the EPFT, and its relation to potential vorticity fluxes, the TWA is an appropriate framework for modeling ocean circulation with parameterized eddies. The authors test the feasibility of this proposition and investigate the connections between the TWA framework and the conventional framework used in models, where Eulerian mean flow prognostic variables are solved for. Using the TWA framework as a starting point, this study explores the well-known connections between vertical transfer of horizontal momentum by eddy form drag and eddy overturning by the bolus velocity, used by Greatbatch and Lamb and Gent and McWilliams to parameterize eddies. After implementing the TWA framework in an ocean general circulation model, we verify our analysis by comparing the flows in an idealized Southern Ocean configuration simulated using the TWA and conventional frameworks with the same mesoscale eddy parameterization.

  2. Groundwater Monitoring

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    program through sampling. August 1, 2013 Conceptual model of water movement and geology at Los Alamos National Laboratory Conceptual model of water movement and geology at...

  3. Computed solid phases limiting the concentration of dissolved constituents in basalt aquifers of the Columbia Plateau in eastern Washington. Geochemical modeling and nuclide/rock/groundwater interaction studies

    SciTech Connect (OSTI)

    Deutsch, W.J.; Jenne, E.A.; Krupka, K.M.

    1982-08-01

    A speciation-solubility geochemical model, WATEQ2, was used to analyze geographically-diverse, ground-water samples from the aquifers of the Columbia Plateau basalts in eastern Washington. The ground-water samples compute to be at equilibrium with calcite, which provides both a solubility control for dissolved calcium and a pH buffer. Amorphic ferric hydroxide, Fe(OH)/sub 3/(A), is at saturation or modestly oversaturated in the few water samples with measured redox potentials. Most of the ground-water samples compute to be at equilibrium with amorphic silica (glass) and wairakite, a zeolite, and are saturated to oversaturated with respect to allophane, an amorphic aluminosilicate. The water samples are saturated to undersaturated with halloysite, a clay, and are variably oversaturated with regard to other secondary clay minerals. Equilibrium between the ground water and amorphic silica presumably results from the dissolution of the glassy matrix of the basalt. The oversaturation of the clay minerals other than halloysite indicates that their rate of formation lags the dissolution rate of the basaltic glass. The modeling results indicate that metastable amorphic solids limit the concentration of dissolved silicon and suggest the same possibility for aluminum and iron, and that the processes of dissolution of basaltic glass and formation of metastable secondary minerals are continuing even though the basalts are of Miocene age. The computed solubility relations are found to agree with the known assemblages of alteration minerals in the basalt fractures and vesicles. Because the chemical reactivity of the bedrock will influence the transport of solutes in ground water, the observed solubility equilibria are important factors with regard to chemical-retention processes associated with the possible migration of nuclear waste stored in the earth's crust.

  4. Modeling of stagnation-line nonequilibrium flows by means of quantum based collisional models

    SciTech Connect (OSTI)

    Munafò, A. Magin, T. E.

    2014-09-15

    The stagnation-line flow over re-entry bodies is analyzed by means of a quantum based collisional model which accounts for dissociation and energy transfer in N{sub 2}-N interactions. The physical model is based on a kinetic database developed at NASA Ames Research Center. The reduction of the kinetic mechanism is achieved by lumping the rovibrational energy levels of the N{sub 2} molecule in energy bins. The energy bins are treated as separate species, thus allowing for non-Boltzmann distributions of their populations. The governing equations are discretized in space by means of the Finite Volume method. A fully implicit time-integration is used to obtain steady-state solutions. The results show that the population of the energy bins strongly deviate from a Boltzmann distribution close to the shock wave and across the boundary layer. The sensitivity analysis to the number of energy bins reveals that accurate estimation of flow quantities (such as chemical composition and wall heat flux) can be obtained by using only 10 energy bins. A comparison with the predictions obtained by means of conventional multi-temperature models indicates that the former can lead to an overestimation of the wall heat flux, due to an inaccurate modeling of recombination in the boundary layer.

  5. Progress in the Development of Compressible, Multiphase Flow Modeling Capability for Nuclear Reactor Flow Applications

    SciTech Connect (OSTI)

    R. A. Berry; R. Saurel; F. Petitpas; E. Daniel; O. Le Metayer; S. Gavrilyuk; N. Dovetta

    2008-10-01

    In nuclear reactor safety and optimization there are key issues that rely on in-depth understanding of basic two-phase flow phenomena with heat and mass transfer. Within the context of multiphase flows, two bubble-dynamic phenomena boiling (heterogeneous) and flashing or cavitation (homogeneous boiling), with bubble collapse, are technologically very important to nuclear reactor systems. The main difference between boiling and flashing is that bubble growth (and collapse) in boiling is inhibited by limitations on the heat transfer at the interface, whereas bubble growth (and collapse) in flashing is limited primarily by inertial effects in the surrounding liquid. The flashing process tends to be far more explosive (and implosive), and is more violent and damaging (at least in the near term) than the bubble dynamics of boiling. However, other problematic phenomena, such as crud deposition, appear to be intimately connecting with the boiling process. In reality, these two processes share many details.

  6. An Expert Elicitation Process in Support of Groundwater Model Evaluation for Frenchman Flat, Nevada National Security Site

    SciTech Connect (OSTI)

    Chapman Jenny,Pohlmann Karl

    2011-02-01

    The U.S. Department of Energy is implementing corrective actions at facilities where nuclear-related operations were conducted in Nevada. Among the most significant sites being addressed are the locations of underground nuclear tests on the Nevada National Security Site (NNSS). The process for implementing corrective actions for the Underground Test Area (UGTA) locations is defined in Appendix VI of a Federal Facility Agreement and Consent Order (1996, as amended). In broad terms, Appendix VI describes a Corrective Action Investigation followed by a Corrective Action Decision, and implementation of a Corrective Action Plan prior to closure. The Frenchman Flat Corrective Action Unit (CAU) is farthest along in the UGTA corrective action process. It includes ten underground tests within the Frenchman Flat topographic basin, in the southeastern portion of the NNSS. Data have been collected from drilling exploration, hydrologic testing, and field and laboratory studies. Modeling has been completed at a variety of scales and focusing on a variety of flow and transport aspects ranging from regional boundary conditions to process dynamics within a single nuclear cavity. The culmination of the investigations is a transport model for the Frenchman Flat CAU (Stoller Navarro Joint Venture, 2009) that has undergone rigorous peer review and been accepted by the State of Nevada, setting the stage for the Corrective Action Decision and progression from the investigation phase to the corrective action phase of the project.

  7. Multiphase flow modeling based on the hyperbolic thermodynamically compatible systems theory

    SciTech Connect (OSTI)

    Romenski, E.

    2015-03-10

    An application of the theory of thermodynamically compatible hyperbolic systems to design a multiphase compressible flow models is discussed. With the use of such approach the governing equations are derived from the first principles, formulated in a divergent form and can be transformed to a symmetric hyperbolic system in the sense of Friedrichs. A usage of the proposed approach is described for the development of multiphase compressible fluid models, including two-phase flow models.

  8. Groundwater Open House! THE SCIENCE CONTINUES The Science Continues

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Welcome to the Groundwater Open House! THE SCIENCE CONTINUES The Science Continues As part of a long-term monitoring program, ongoing scientific studies will continue into the future to identify where contaminated groundwater is located, in which direction it flows and its rate of movement. Find the latest data on posters marked with this symbol. YOUR WATER IS SAFE The Groundwater is Safe Public water supply is safe from the impacts of historic underground nuclear testing. Current research

  9. The Hanford Story: Groundwater

    Broader source: Energy.gov [DOE]

    This second chapter of The Hanford Story explains how more than 100 square miles of groundwater under the Hanford Site became contaminated and what workers are doing to restore groundwater to its highest beneficial use.

  10. Nitrate Biogeochemistry and Reactive Transport in California Groundwater: LDRD Final Report

    SciTech Connect (OSTI)

    Esser, B K; Beller, H; Carle, S; Cey, B; Hudson, G B; Leif, R; LeTain, T; Moody-Bartel, C; Moore, K; McNab, W; Moran, J; Tompson, A

    2006-02-24

    Nitrate is the number one drinking water contaminant in the United States. It is pervasive in surface and groundwater systems,and its principal anthropogenic sources have increased dramatically in the last 50 years. In California alone, one third of the public drinking-water wells has been lost since 1988 and nitrate contamination is the most common reason for abandonment. Effective nitrate management in groundwater is complicated by uncertainties related to multiple point and non-point sources, hydrogeologic complexity, geochemical reactivity, and quantification of denitrification processes. In this paper, we review an integrated experimental and simulation-based framework being developed to study the fate of nitrate in a 25 km-long groundwater subbasin south of San Jose, California, a historically agricultural area now undergoing rapid urbanization with increasing demands for groundwater. The modeling approach is driven by a need to integrate new and archival data that support the hypothesis that nitrate fate and transport at the basin scale is intricately related to hydrostratigraphic complexity, variability of flow paths and groundwater residence times, microbial activity, and multiple geochemical reaction mechanisms. This study synthesizes these disparate and multi-scale data into a three-dimensional and highly resolved reactive transport modeling framework.

  11. The Tritium Under-flow Study at the Savannah River Site

    SciTech Connect (OSTI)

    Hiergesell, Robert A.

    2008-01-15

    An issue of concern at the Savannah River Site (SRS) over the past 20 years is whether tritiated groundwater originating at SRS might be the cause of low levels of tritium measured in certain domestic wells in Georgia. Tritium activity levels in several domestic wells have been observed to occur at levels comparable to what is measured in rainfall in areas surrounding SRS. Since 1988, there has been speculation that tritiated groundwater from SRS could flow under the river and find its way into Georgia wells. A considerable effort was directed at assessing the likelihood of trans-river flow, and 44 wells have been drilled by the USGS and the Georgia Department of Natural Resources. Also, as part of the data collection and analysis, the USGS developed a numerical model during 1997-98 to assess the possibility for such trans-river flow to occur. The model represented the regional groundwater flow system surrounding the Savannah River Site (SRS) in seven layers corresponding to the underlying hydrostratigraphic units, which was regarded as sufficiently detailed to evaluate whether groundwater originating at SRS could possibly flow beneath the Savannah River into Georgia. The model was calibrated against a large database of water-level measurements obtained from wells on both sides of the Savannah River and screened in each of the hydrostratigraphic units represented within the model. The model results verified that the groundwater movement in all hydrostratigraphic units proceeds laterally toward the Savannah River from both South Carolina and Georgia, and discharges into the river. Once the model was calibrated, a particle-track analysis was conducted to delineate areas of potential trans-river flow. Trans-river flow can occur in either an eastward or westward direction. The model indicated that all locations of trans-river flow are restricted to the Savannah River's flood plain, where groundwater passes immediately prior to discharging into the river. Whether the

  12. Numerical modeling of carrier gas flow in atomic layer deposition vacuum reactor: A comparative study of lattice Boltzmann models

    SciTech Connect (OSTI)

    Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: cyuan@uwm.edu [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)

    2014-01-15

    This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice BhatnagarGrossKrook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.

  13. SCDAP/RELAP5 Modeling of Heat Transfer and Flow Losses in Lower Head Porous Debris

    SciTech Connect (OSTI)

    Siefken, Larry James; Coryell, Eric Wesley; Paik, Seungho; Kuo, Han Hsiung

    1999-07-01

    Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and nonporous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of nonporous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate manner. Designs are described for models to calculate the flow losses and interphase drag of fluid flowing through the interstices of the porous debris, and to apply these variables in the momentum equations in the RELAP5 part of the code. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models is also expected to improve the calculation of the temperature and flow distribution in porous debris in the core region.

  14. Development of a Groundwater Transport Simulation Tool for Remedial Process Optimization

    SciTech Connect (OSTI)

    Ivarson, Kristine A.; Hanson, James P.; Tonkin, M.; Miller, Charles W.; Baker, S.

    2015-01-14

    The groundwater remedy for hexavalent chromium at the Hanford Site includes operation of five large pump-and-treat systems along the Columbia River. The systems at the 100-HR-3 and 100-KR-4 groundwater operable units treat a total of about 9,840 liters per minute (2,600 gallons per minute) of groundwater to remove hexavalent chromium, and cover an area of nearly 26 square kilometers (10 square miles). The pump-and-treat systems result in large scale manipulation of groundwater flow direction, velocities, and most importantly, the contaminant plumes. Tracking of the plumes and predicting needed system modifications is part of the remedial process optimization, and is a continual process with the goal of reducing costs and shortening the timeframe to achieve the cleanup goals. While most of the initial system evaluations are conducted by assessing performance (e.g., reduction in contaminant concentration in groundwater and changes in inferred plume size), changes to the well field are often recommended. To determine the placement for new wells, well realignments, and modifications to pumping rates, it is important to be able to predict resultant plume changes. In smaller systems, it may be effective to make small scale changes periodically and adjust modifications based on groundwater monitoring results. Due to the expansive nature of the remediation systems at Hanford, however, additional tools were needed to predict the plume reactions to system changes. A computer simulation tool was developed to support pumping rate recommendations for optimization of large pump-and-treat groundwater remedy systems. This tool, called the Pumping Optimization Model, or POM, is based on a 1-layer derivation of a multi-layer contaminant transport model using MODFLOW and MT3D.

  15. Symmetry Methods for a Geophysical Mass Flow Model

    SciTech Connect (OSTI)

    Torrisi, Mariano; Tracina, Rita

    2011-09-14

    In the framework of symmetry analysis, the class of 2 x 2 PDE systems to whom belong the Savage and Hutter model and the Iverson model is considered. New classes of exact solutions are found.

  16. Toward a new parameterization of hydraulic conductivity in climate models: Simulation of rapid groundwater fluctuations in Northern California: HYDRAULIC CONDUCTIVITY IN CLIMATE MODELS

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vrettas, Michail D.; Fung, Inez Y.

    2015-12-01

    Preferential flow through weathered bedrock leads to rapid rise of the water table after the first rainstorms and significant water storage (also known as ‘‘rock moisture’’) in the fractures. We present a new parameterization of hydraulic conductivity that captures the preferential flow and is easy to implement in global climate models. To mimic the naturally varying heterogeneity with depth in the subsurface, the model represents the hydraulic conductivity as a product of the effective saturation and a background hydraulic conductivity Kbkg, drawn from a lognormal distribution. The mean of the background Kbkg decreases monotonically with depth, while its variance reducesmore » with the effective saturation. Model parameters are derived by assimilating into Richards’ equation 6 years of 30 min observations of precipitation (mm) and water table depths (m), from seven wells along a steep hillslope in the Eel River watershed in Northern California. The results show that the observed rapid penetration of precipitation and the fast rise of the water table from the well locations, after the first winter rains, are well captured with the new stochastic approach in contrast to the standard van Genuchten model of hydraulic conductivity, which requires significantly higher levels of saturated soils to produce the same results. ‘‘Rock moisture,’’ the moisture between the soil mantle and the water table, comprises 30% of the moisture because of the great depth of the weathered bedrock layer and could be a potential source of moisture to sustain trees through extended dry periods. Furthermore, storage of moisture in the soil mantle is smaller, implying less surface runoff and less evaporation, with the proposed new model.« less

  17. COMIS -- an international multizone air-flow and contaminant transport model

    SciTech Connect (OSTI)

    Feustel, H.E.

    1998-08-01

    A number of interzonal models have been developed to calculate air flows and pollutant transport mechanisms in both single and multizone buildings. A recent development in multizone air-flow modeling, the COMIS model, has a number of capabilities that go beyond previous models, much as COMIS can be used as either a stand-alone air-flow model with input and output features or as an infiltration module for thermal building simulation programs. COMIS was designed during a 12 month workshop at Lawrence Berkeley National Laboratory (LBNL) in 1988-89. In 1990, the Executive Committee of the International Energy Agency`s Energy Conservation in Buildings and Community Systems program created a working group on multizone air-flow modeling, which continued work on COMIS. The group`s objectives were to study physical phenomena causing air flow and pollutant (e.g., moisture) transport in multizone buildings, develop numerical modules to be integrated in the previously designed multizone air flow modeling system, and evaluate the computer code. The working group supported by nine nations, officially finished in late 1997 with the release of IISiBat/COMIS 3.0, which contains the documented simulation program COMIS, the user interface IISiBat, and reports describing the evaluation exercise.

  18. Direct pore-level modeling of incompressible fluid flow in porous media

    SciTech Connect (OSTI)

    Ovaysi, Saeed; Piri, Mohammad

    2010-09-20

    We present a dynamic particle-based model for direct pore-level modeling of incompressible viscous fluid flow in disordered porous media. The model is capable of simulating flow directly in three-dimensional high-resolution micro-CT images of rock samples. It is based on moving particle semi-implicit (MPS) method. We modify this technique in order to improve its stability for flow in porous media problems. Using the micro-CT image of a rock sample, the entire medium, i.e., solid and fluid, is discretized into particles. The incompressible Navier-Stokes equations are then solved for each particle using the MPS summations. The model handles highly irregular fluid-solid boundaries effectively. An algorithm to split and merge fluid particles is also introduced. To handle the computational load, we present a parallel version of the model that runs on distributed memory computer clusters. The accuracy of the model is validated against the analytical, numerical, and experimental data available in the literature. The validated model is then used to simulate both unsteady- and steady-state flow of an incompressible fluid directly in a representative elementary volume (REV) size micro-CT image of a naturally-occurring sandstone with 3.398 {mu}m resolution. We analyze the quality and consistency of the predicted flow behavior and calculate absolute permeability using the steady-state flow rate.

  19. Computer modeling of electromagnetic fields and fluid flows for edge containment in continuous casting

    SciTech Connect (OSTI)

    Chang, F.C.; Hull, J.R.; Wang, Y.H.; Blazek, K.E.

    1996-02-01

    A computer model was developed to predict eddy currents and fluid flows in molten steel. The model was verified by comparing predictions with experimental results of liquid-metal containment and fluid flow in electromagnetic (EM) edge dams (EMDs) designed at Inland Steel for twin-roll casting. The model can optimize the EMD design so it is suitable for application, and minimize expensive, time-consuming full-scale testing. Numerical simulation was performed by coupling a three-dimensional (3-D) finite-element EM code (ELEKTRA) and a 3-D finite-difference fluids code (CaPS-EM) to solve heat transfer, fluid flow, and turbulence transport in a casting process that involves EM fields. ELEKTRA is able to predict the eddy- current distribution and the electromagnetic forces in complex geometries. CaPS-EM is capable of modeling fluid flows with free surfaces. Results of the numerical simulation compared well with measurements obtained from a static test.

  20. Improved blade profile loss and deviation angle models for advanced transonic compressor bladings. Part 2: A model for supersonic flow

    SciTech Connect (OSTI)

    Koenig, W.M.; Hennecke, D.K.; Fottner, L.

    1996-01-01

    New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. The second part of the present report focuses on the extension of a well-known correlation for cascade losses at supersonic inlet flows. It was originally established for DCA bladings and is now modified to reflect the flow situation in blade rows having low-cambered, arbitrarily designed blades including precompression blades. Finally, the steady loss increase from subsonic to supersonic inlet-flow velocities demonstrates the matched performance of the different correlations of the new model.

  1. Phase I Flow and Transport Model Document for Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada National Security Site, Nye County, Nevada, Revision 1 with ROTCs 1 and 2

    SciTech Connect (OSTI)

    Andrews, Robert

    2013-09-01

    The Underground Test Area (UGTA) Corrective Action Unit (CAU) 97, Yucca Flat/Climax Mine, in the northeast part of the Nevada National Security Site (NNSS) requires environmental corrective action activities to assess contamination resulting from underground nuclear testing. These activities are necessary to comply with the UGTA corrective action strategy (referred to as the UGTA strategy). The corrective action investigation phase of the UGTA strategy requires the development of groundwater flow and contaminant transport models whose purpose is to identify the lateral and vertical extent of contaminant migration over the next 1,000 years. In particular, the goal is to calculate the contaminant boundary, which is defined as a probabilistic model-forecast perimeter and a lower hydrostratigraphic unit (HSU) boundary that delineate the possible extent of radionuclide-contaminated groundwater from underground nuclear testing. Because of structural uncertainty in the contaminant boundary, a range of potential contaminant boundaries was forecast, resulting in an ensemble of contaminant boundaries. The contaminant boundary extent is determined by the volume of groundwater that has at least a 5 percent chance of exceeding the radiological standards of the Safe Drinking Water Act (SDWA) (CFR, 2012).

  2. Geochemical and Isotopic Evaluation of Groundwater Movement in Corrective Action Unit 97: Yucca Flat/Climax Mine, Nevada Test Site, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    Farnham, Irene

    2006-02-01

    This report describes the results of a comprehensive geochemical evaluation of the groundwater flow system in the Yucca Flat/Climax Mine Corrective Action Unit (CAU). The main objectives of this study are to identify probable pathways for groundwater flow within the study area and to develop constraints on groundwater transit times between selected data collection sites. This work provides an independent means of testing and verifying predictive flow models being developed for this CAU using finite element methods. The Yucca Flat/Climax Mine CAU constitutes the largest of six underground test areas on the Nevada Test Site (NTS) specified for remedial action in the ''Federal Facility Agreement and Consent Order''. A total of 747 underground nuclear detonations were conducted in this CAU. Approximately 23 percent of these detonations were conducted below or near the water table, resulting in groundwater contamination in the vicinity and possibly downgradient of these underground test locations. Therefore, a rigorous evaluation of the groundwater flow system in this CAU is necessary to assess potential long-term risks to the public water supply at downgradient locations.

  3. A Multidimensional Eulerian Model for Simulating Gas-Solids Flow

    Energy Science and Technology Software Center (OSTI)

    1993-12-13

    FORCE2 is a fundamentally based three-dimensional numerical model for simulating fluid-bed hydrodynamics for a wide range of fluid beds, from laboratory to plant scale. It is based upon the ''two-fluid'' modeling approach and includes surface permeabilities, volume porosities, and distributed resistances.

  4. Appendix K Disposal Cell Groundwater Monitoring Plan

    Office of Legacy Management (LM)

    K Disposal Cell Groundwater Monitoring Plan

  5. Can We Accurately Model Fluid Flow in Shale?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The source of shale oil and gas is kerogen, an organic material in the shale, but until now kerogen hasn't been incorporated in mathematical models of shale gas reservoirs. Paulo ...

  6. Boundary layer modeling of reactive flow over a porous surface with angled injection

    SciTech Connect (OSTI)

    Liu, Shiling; Fotache, Catalin G.; Hautman, Donald J.; Ochs, Stuart S. [United Technologies Research Center, MS 129-29, 411 Silver Lane, East Hartford, CT 06108 (United States); Chao, Beei-Huan [Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2008-08-15

    An analytical model was developed to investigate the dynamics of nonpremixed flames in a shear layer established between a mainstream flow of fuel-rich combustion products and a porous surface with an angled injection of air. In the model, a one-step overall chemical reaction was employed, together with boundary layer conservation equations solved using similarity solutions. Parametric studies were performed to understand the effects of equivalence ratio, temperature, and mass flow rate of the fuel and air streams on the flame standoff distance, surface temperature, and heat flux at the surface. The analytical model predictions were compared with computational fluid dynamics results obtained using the FLUENT commercial code for both the laminar and the turbulent flow models. Qualitative agreement in surface temperature was observed. Finally, the flame stability limits predicted by the model were compared with available experimental data and found to agree qualitatively, as well. (author)

  7. A Fresh Take on Groundwater at Amargosa Valley Open House

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    September 25, 2012 A Fresh Take on Groundwater at Amargosa Valley Open House From drilling ... Interactive stations on Monitoring, Drilling, Sampling, Modeling, Protection and ...

  8. A hybrid stochastic-deconvolution model for large-eddy simulation of particle-laden flow

    SciTech Connect (OSTI)

    Michałek, W. R.; Kuerten, J. G. M.; Faculty EEMCS, University of Twente, 7500 AE Enschede ; Zeegers, J. C. H.; Liew, R.; Pozorski, J.; Geurts, B. J.; Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven

    2013-12-15

    We develop a hybrid model for large-eddy simulation of particle-laden turbulent flow, which is a combination of the approximate deconvolution model for the resolved scales and a stochastic model for the sub-grid scales. The stochastic model incorporates a priori results of direct numerical simulation of turbulent channel flow, which showed that the parameters in the stochastic model are quite independent of Reynolds and Stokes number. In order to correctly predict the flux of particles towards the walls an extra term should be included in the stochastic model, which corresponds to the term related to the well-mixed condition in Langevin models for particle dispersion in inhomogeneous turbulent flow. The model predictions are compared with results of direct numerical simulation of channel flow at a frictional Reynolds number of 950. The inclusion of the stochastic forcing is shown to yield a significant improvement over the approximate deconvolution model for the particles alone when combined with a Stokes dependent weight-factor for the well-mixed term.

  9. NEW MODEL AND MEASUREMENT PRINCIPLE OF FLOWING AND HEAT TRANSFER CHARACTERISTICS OF REGENERATOR

    SciTech Connect (OSTI)

    Chen, Y. Y.; Luo, E. C.; Dai, W.

    2008-03-16

    Regenerators play key role in oscillating-flow cryocoolers or thermoacoustic heat engine systems. However, their flowing and heat transfer mechanism is still not well understood. The complexities of the oscillating flow regenerator make traditional method of heat transfer research become difficult or helpless. In this paper, a model for porous media regenerator was given based on the linear thermoacoustic theory. Then the correlations for characteristic parameters were obtained by deducing universal expressions for thermoacoustic viscous function F{sub v} and thermal function F{sub T}. A simple acoustical method and experimental system to get F{sub v} and F{sub T} via measurements of isothermal regenerators were presented. Some measurements of packed stainless screen regenerators were performed, and preliminary experimental results for flow and convective coefficients were derived, which showing flowing friction factor is approximately within 132/Re to 173/Re.

  10. Estimation of Groundwater Recharge at Pahute Mesa using the Chloride Mass-Balance Method

    SciTech Connect (OSTI)

    Cooper, Clay A; Hershey, Ronald L; Healey, John M; Lyles, Brad F

    2013-07-01

    Groundwater recharge on Pahute Mesa was estimated using the chloride mass-balance (CMB) method. This method relies on the conservative properties of chloride to trace its movement from the atmosphere as dry- and wet-deposition through the soil zone and ultimately to the saturated zone. Typically, the CMB method assumes no mixing of groundwater with different chloride concentrations; however, because groundwater is thought to flow into Pahute Mesa from valleys north of Pahute Mesa, groundwater flow rates (i.e., underflow) and chloride concentrations from Kawich Valley and Gold Flat were carefully considered. Precipitation was measured with bulk and tipping-bucket precipitation gauges installed for this study at six sites on Pahute Mesa. These data, along with historical precipitation amounts from gauges on Pahute Mesa and estimates from the PRISM model, were evaluated to estimate mean annual precipitation. Chloride deposition from the atmosphere was estimated by analyzing quarterly samples of wet- and dry-deposition for chloride in the bulk gauges and evaluating chloride wet-deposition amounts measured at other locations by the National Atmospheric Deposition Program. Mean chloride concentrations in groundwater were estimated using data from the UGTA Geochemistry Database, data from other reports, and data from samples collected from emplacement boreholes for this study. Calculations were conducted assuming both no underflow and underflow from Kawich Valley and Gold Flat. Model results estimate recharge to be 30 mm/yr with a standard deviation of 18 mm/yr on Pahute Mesa, for elevations >1800 m amsl. These estimates assume Pahute Mesa recharge mixes completely with underflow from Kawich Valley and Gold Flat. The model assumes that precipitation, chloride concentration in bulk deposition, underflow and its chloride concentration, have been constant over the length of time of recharge.

  11. Improved blade profile loss and deviation angle models for advanced transonic compressor bladings. Part 1: A model for subsonic flow

    SciTech Connect (OSTI)

    Koenig, W.M.; Hennecke, D.K.; Fottner, L.

    1996-01-01

    New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. In the first part of this paper two proved and well-established profile loss correlations for subsonic flows are extended to quasi-two-dimensional conditions and to custom-tailored blade designs. Instead of a deviation angle correlation, a simple method based on singularities is utilized. The comparison between the new model and a recently published model demonstrates the improved accuracy in prediction of cascade performance achieved by the new model.

  12. Hanford Site Groundwater Monitoring for Fiscal Year 1998

    SciTech Connect (OSTI)

    Hartman, M.J.

    1999-03-24

    This report presents the results of groundwater and vadose-zone monitoring and remediation for fiscal year (FY) 1998 on the Word Site, Washington. Soil-vapor extraction in the 200-West Area removed 777 kg of carbon tetrachloride in FY 1998, for a total of 75,490 kg removed since remediation began in 1992. Spectral gamma logging and evaluation of historical gross gamma logs near tank farms and liquid-disposal sites in the 200 Areas provided information on movement of contaminants in the vadose zone. Water-level monitoring was performed to evaluate groundwater-flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Water levels over most of the Hanford Site continued to decline between June 1997 and June 1998. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of technetium-99, uranium, strontium-90, and carbon-14 also exceeded drinking water standards in smaller plumes. Plutonium and cesium-137 exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in U.S. Department of Energy Order 5400.5 were exceeded for tritium, uranium, strontium-90, and plutonium in small plumes or single wells. One well completed in the basalt-confined aquifer beneath the 200-East Area exceeded the drinking water standard for technetium-99. Nitrate is the most extensive chemical contaminant. Carbon tetrachloride, chloroform, chromium, cis-l, Z-dichloroethylene, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Cyanide concentrations were elevated in one area but were below the maximum contaminant level. Tetrachloroethylene exceeded its maximum contaminant level in several wells in the 300 Area for the first time since the 1980s. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels in filtered samples from numerous

  13. A numerical study of short residence time FCC riser flows with a new flow/kinetics modeling technique.

    SciTech Connect (OSTI)

    Chang, S. L.

    1998-08-25

    Fluid Catalytic Cracking (FCC) technology is the most important process used by the refinery industry to convert crude oil to valuable lighter products such as gasoline. New and modified processes are constantly developed by refinery companies to improve their global competitiveness and meet more stringent environmental regulations. Short residence time FCC riser reactor is one of the advanced processes that the refining industry is actively pursuing because it can improve the yield selectivity and efficiency of an FCC unit. However, as the residence time becomes shorter, the impact of the mixing between catalyst and feed oil at the feed injection region on the product yield becomes more significant. Currently, most FCC computer models used by the refineries perform sophisticated kinetic calculations on simplified flow field and can not be used to evaluate the impact of fluid mixing on the performance of an FCC unit. Argonne National Laboratory (AFL) is developing a computational fluid dynamic (CFD) code ICRKFLO for FCC riser flow modeling. The code, employing hybrid hydrodynamic-chemical kinetic coupling techniques, is used to investigate the effect of operating and design conditions on the product yields of FCC riser reactors. Numerical calculations were made using the code to examine the impacts of the operating and design conditions on the product yields. The controlling parameters under investigation include the residence time, reaction temperature, and catalyst/oil ratio. This paper describes the CFD code, presents computation results, and discusses the effects of operating conditions on the performance of short residence time FCC riser reactors.

  14. Estimation of unsaturated zone traveltimes for Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nevada, using a source-responsive preferential-flow model

    SciTech Connect (OSTI)

    Brian A. Ebel; John R. Nimmo

    2009-09-11

    Traveltimes for contaminant transport by water from a point in the unsaturated zone to the saturated zone are a concern at Rainier Mesa and Shoshone Mountain in the Nevada Test Site, Nevada. Where nuclear tests were conducted in the unsaturated zone, contaminants must traverse hundreds of meters of variably saturated rock before they enter the saturated zone in the carbonate rock, where the regional groundwater system has the potential to carry them substantial distances to a location of concern. The unsaturated-zone portion of the contaminant transport path may cause a significant delay, in addition to the time required to travel within the saturated zone, and thus may be important in the overall evaluation of the potential hazard from contamination. Downward contaminant transport through the unsaturated zone occurs through various processes and pathways; this can lead to a broad distribution of contaminant traveltimes, including exceedingly slow and unexpectedly fast extremes. Though the bulk of mobile contaminant arrives between the time-scale end members, the fastest contaminant transport speed, in other words the speed determined by the combination of possible processes and pathways that would bring a measureable quantity of contaminant to the aquifer in the shortest time, carries particular regulatory significance because of its relevance in formulating the most conservative hazard-prevention scenarios. Unsaturated-zone flow is usually modeled as a diffusive process responding to gravity and pressure gradients as mediated by the unsaturated hydraulic properties of the materials traversed. The mathematical formulation of the diffuse-flow concept is known as Richards' equation, which when coupled to a solute transport equation, such as the advection-dispersion equation, provides a framework to simulate contaminant migration in the unsaturated zone. In recent decades awareness has increased that much fluid flow and contaminant transport within the unsaturated

  15. Situ treatment of contaminated groundwater

    DOE Patents [OSTI]

    McNab, Jr., Walt W.; Ruiz, Roberto; Pico, Tristan M.

    2001-01-01

    A system for treating dissolved halogenated organic compounds in groundwater that relies upon electrolytically-generated hydrogen to chemically reduce the halogenated compounds in the presence of a suitable catalyst. A direct current is placed across at least a pair, or an array, of electrodes which are housed within groundwater wells so that hydrogen is generated at the cathode and oxygen at the anode. A pump is located within the well housing in which the cathode(s) is(are) located and draws in groundwater where it is hydrogenated via electrolysis, passes through a well-bore treatment unit, and then transported to the anode well(s) for reinjection into the ground. The well-bore treatment involves a permeable cylinder located in the well bore and containing a packed bed of catalyst material that facilitates the reductive dehalogenation of the halogenated organic compounds by hydrogen into environmentally benign species such as ethane and methane. Also, electro-osmatic transport of contaminants toward the cathode also contributes to contaminant mass removal. The only above ground equipment required are the transfer pipes and a direct circuit power supply for the electrodes. The electrode wells in an array may be used in pairs or one anode well may be used with a plurality of cathode wells. The DC current flow between electrode wells may be periodically reversed which controls the formation of mineral deposits in the alkaline cathode well-bore water, as well as to help rejuvenate the catalysis.

  16. Potential Hydraulic Modelling Errors Associated with Rheological Data Extrapolation in Laminar Flow

    SciTech Connect (OSTI)

    Shadday, Martin A., Jr.

    1997-03-20

    The potential errors associated with the modelling of flows of non-Newtonian slurries through pipes, due to inadequate rheological models and extrapolation outside of the ranges of data bases, are demonstrated. The behaviors of both dilatant and pseudoplastic fluids with yield stresses, and the errors associated with treating them as Bingham plastics, are investigated.

  17. Groundwater Monitoring Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    92 natural sources, 102 regional aquifer wells, 41 intermediate-depth wells and springs, and 67 wells in alluvium in canyons. August 1, 2013 Map of LANL's groundwater...

  18. Source Term Modeling for Evaluating the Potential Impacts to Groundwater of Fluids Escaping from a Depleted Oil Reservoir Used for Carbon Sequestration

    SciTech Connect (OSTI)

    Cantrell, Kirk J.; Brown, Christopher F.

    2014-06-13

    In recent years depleted oil reservoirs have received special interest as carbon storage reservoirs because of their potential to offset costs through collaboration with enhanced oil recovery projects. Modeling is currently being conducted to evaluate potential risks to groundwater associated with leakage of fluids from depleted oil reservoirs used for storage of CO2. Modeling results reported here focused on understanding how toxic organic compounds found in oil will distribute between the various phases within a storage reservoir after introduction of CO2, understanding the migration potential of these compounds, and assessing potential groundwater impacts should leakage occur. Two model scenarios were conducted to evaluate how organic components in oil will distribute among the phases of interest (oil, CO2, and brine). The first case consisted of 50 wt.% oil and 50 wt.% water; the second case was 90 wt.% CO2 and 10 wt.% oil. Several key organic compounds were selected for special attention in this study based upon their occurrence in oil at significant concentrations, relative toxicity, or because they can serve as surrogate compounds for other more highly toxic compounds for which required input data are not available. The organic contaminants of interest (COI) selected for this study were benzene, toluene, naphthalene, phenanthrene, and anthracene. Partitioning of organic compounds between crude oil and supercritical CO2 was modeled using the Peng-Robinson equation of state over temperature and pressure conditions that represent the entire subsurface system (from those relevant to deep geologic carbon storage environments to near surface conditions). Results indicate that for a typical set of oil reservoir conditions (75°C, and 21,520 kPa) negligible amounts of the COI dissolve into the aqueous phase. When CO2 is introduced into the reservoir such that the final composition of the reservoir is 90 wt.% CO2 and 10 wt.% oil, a significant fraction of the oil

  19. Multiphase Flow Modeling - Validation and Application CRADA MC94-019, Final Report

    SciTech Connect (OSTI)

    Madhava Syamlal; Philip A. Nicoletti

    1995-08-31

    For the development and validation of multiphase flow modeling capability, a cooperative research and development agreement (CRADA) is in effect between Morgantown Energy Technology Center (METC) and Fluent Inc. To validate the Fluent multiphase model, several simulations were conducted at METC and the results were compared with the results of MFIX, a multiphase flow code developed at METC, and with experimental data. The results of these validation studies will be presented. In addition, the application of multiphase flow modeling will be illustrated by presenting the results of simulations of a filter back- flushing and a fluidized bed coal gasifier. These simulations were conducted only with MFIX, since certain features needed in these simulations will be available only in the next release of Fluent.

  20. Measurement of Flow Phenomena in a Lower Plenum Model of a Prismatic Gas-Cooled Reactor

    SciTech Connect (OSTI)

    Hugh M. McIlroy, Jr.; Donald M. McEligot; Robert J. Pink

    2008-05-01

    Mean-velocity-field and turbulence data are presented that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. The data were obtained in the Matched-Index-of-Refraction (MIR) facility at Idaho National Laboratory (INL) and are offered for assessing computational fluid dynamics (CFD) software. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. This paper reviews the experimental apparatus and procedures, presents a sample of the data set, and reviews the INL Standard Problem. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid so that optical techniques may be employed for the measurements. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages in and around objects to be obtained without locating intrusive transducers that will disturb the flow field and without distortion of the optical paths. An advantage of the INL system is its large size, leading to improved spatial and temporal resolution compared to similar facilities at smaller scales. A three-dimensional (3-D) Particle Image Velocimetry (PIV) system was used to collect the data. Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12

  1. Protection of the Groundwater Resource

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Protection of the Groundwater Resource Protection of the Groundwater Resource Monitoring wells act as sentinels between suspected LANL contamination and the water supply. August 1,...

  2. Physical Model Development and Benchmarking for MHD Flows in Blanket Design

    SciTech Connect (OSTI)

    Ramakanth Munipalli; P.-Y.Huang; C.Chandler; C.Rowell; M.-J.Ni; N.Morley; S.Smolentsev; M.Abdou

    2008-06-05

    An advanced simulation environment to model incompressible MHD flows relevant to blanket conditions in fusion reactors has been developed at HyPerComp in research collaboration with TEXCEL. The goals of this phase-II project are two-fold: The first is the incorporation of crucial physical phenomena such as induced magnetic field modeling, and extending the capabilities beyond fluid flow prediction to model heat transfer with natural convection and mass transfer including tritium transport and permeation. The second is the design of a sequence of benchmark tests to establish code competence for several classes of physical phenomena in isolation as well as in select (termed here as canonical,) combinations. No previous attempts to develop such a comprehensive MHD modeling capability exist in the literature, and this study represents essentially uncharted territory. During the course of this Phase-II project, a significant breakthrough was achieved in modeling liquid metal flows at high Hartmann numbers. We developed a unique mathematical technique to accurately compute the fluid flow in complex geometries at extremely high Hartmann numbers (10,000 and greater), thus extending the state of the art of liquid metal MHD modeling relevant to fusion reactors at the present time. These developments have been published in noted international journals. A sequence of theoretical and experimental results was used to verify and validate the results obtained. The code was applied to a complete DCLL module simulation study with promising results.

  3. Draft: Modeling Two-Phase Flow in Porous Media Including Fluid-Fluid Interfacial Area

    SciTech Connect (OSTI)

    Crandall, Dustin; Niessner, Jennifer; Hassanizadeh, S Majid

    2008-01-01

    We present a new numerical model for macro-scale twophase flow in porous media which is based on a physically consistent theory of multi-phase flow.The standard approach for modeling the flow of two fluid phases in a porous medium consists of a continuity equation for each phase, an extended form of Darcy’s law as well as constitutive relationships for relative permeability and capillary pressure. This approach is known to have a number of important shortcomings and, in particular, it does not account for the presence and role of fluid - fluid interfaces. An alternative is to use an extended model which is founded on thermodynamic principles and is physically consistent. In addition to the standard equations, the model uses a balance equation for specific interfacial area. The constitutive relationship for capillary pressure involves not only saturation, but also specific interfacial area. We show how parameters can be obtained for the alternative model using experimental data from a new kind of flow cell and present results of a numerical modeling study

  4. Analytical solution for two-phase flow in a wellbore using the drift-flux model

    SciTech Connect (OSTI)

    Pan, L.; Webb, S.W.; Oldenburg, C.M.

    2011-11-01

    This paper presents analytical solutions for steady-state, compressible two-phase flow through a wellbore under isothermal conditions using the drift flux conceptual model. Although only applicable to highly idealized systems, the analytical solutions are useful for verifying numerical simulation capabilities that can handle much more complicated systems, and can be used in their own right for gaining insight about two-phase flow processes in wells. The analytical solutions are obtained by solving the mixture momentum equation of steady-state, two-phase flow with an assumption that the two phases are immiscible. These analytical solutions describe the steady-state behavior of two-phase flow in the wellbore, including profiles of phase saturation, phase velocities, and pressure gradients, as affected by the total mass flow rate, phase mass fraction, and drift velocity (i.e., the slip between two phases). Close matching between the analytical solutions and numerical solutions for a hypothetical CO{sub 2} leakage problem as well as to field data from a CO{sub 2} production well indicates that the analytical solution is capable of capturing the major features of steady-state two-phase flow through an open wellbore, and that the related assumptions and simplifications are justified for many actual systems. In addition, we demonstrate the utility of the analytical solution to evaluate how the bottomhole pressure in a well in which CO{sub 2} is leaking upward responds to the mass flow rate of CO{sub 2}-water mixture.

  5. CURRENT - A Computer Code for Modeling Two-Dimensional, Chemically Reaccting, Low Mach Number Flows

    SciTech Connect (OSTI)

    Winters, W.S.; Evans, G.H.; Moen, C.D.

    1996-10-01

    This report documents CURRENT, a computer code for modeling two- dimensional, chemically reacting, low Mach number flows including the effects of surface chemistry. CURRENT is a finite volume code based on the SIMPLER algorithm. Additional convergence acceleration for low Peclet number flows is provided using improved boundary condition coupling and preconditioned gradient methods. Gas-phase and surface chemistry is modeled using the CHEMKIN software libraries. The CURRENT user-interface has been designed to be compatible with the Sandia-developed mesh generator and post processor ANTIPASTO and the post processor TECPLOT. This report describes the theory behind the code and also serves as a user`s manual.

  6. Solution Algorithms for Effective-Field Models of Multi-Fluid Flows

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: Solution Algorithms for Effective-Field Models of Multi-Fluid Flows Citation Details In-Document Search Title: Solution Algorithms for Effective-Field Models of Multi-Fluid Flows Authors: Robert Nourgaliev ; Mark Christon Publication Date: 2012-09-01 OSTI Identifier: 1058095 Report Number(s): INL/EXT-12-27187 DOE Contract Number: DE-AC07-05ID14517 Resource Type: Technical Report Research Org: Idaho National Laboratory (INL) Sponsoring

  7. Grid Generator for Two, Three-dimensional Finite Element Subsurface Flow Models

    Energy Science and Technology Software Center (OSTI)

    1993-04-28

    GRIDMAKER serves as a preprocessor for finite element models in solving two- and three-dimensional subsurface flow and pollutant transport problems. It is designed to generate three-point triangular or four-point quadrilateral elements for two-dimensional domains and eight-point hexahedron elements for three-dimensional domains. A two-dimensional domain of an aquifer with a variable depth layer is treated as a special case for depth-integrated two-dimensional, finite element subsurface flow models. The program accommodates the need for aquifers with heterogeneousmore » systems by identifying the type of material in each element.« less

  8. Dividing phases in two-phase flow and modeling of interfacial drag

    SciTech Connect (OSTI)

    Narumo, T.; Rajamaeki, M.

    1997-07-01

    Different models intended to describe one-dimensional two-phase flow are considered in this paper. The following models are introduced: conventional six-equation model, conventional model equipped with terms taking into account nonuniform transverse velocity distribution of the phases, several virtual mass models and a model in which the momentum equations have been derived by using the principles of Separation of the Flow According to Velocity (SFAV). The dynamics of the models have been tested by comparing their characteristic velocities to each other and against experimental data. The results show that the SFAV-model makes a hyperbolic system and predicts the propagation velocities of disturbances with the same order of accuracy as the best tested virtual mass models. Furthermore, the momentum interaction terms for the SFAV-model are considered. These consist of the wall friction terms and the interfacial friction term. The authors model wall friction with two independent terms describing the effect of each fluid on the wall separately. In the steady state, a relationship between the slip velocity and friction coefficients can be derived. Hence, the friction coefficients for the SFAV-model can be calculated from existing correlations, viz. from a drift-flux correlation and a wall friction correlation. The friction model was tested by searching steady-state distributions in a partial BWR fuel channel and comparing the relaxed values with the drift-flux correlation, which agreed very well with each other. In addition, response of the flow to a sine-wave disturbance in the water inlet flux was calculated as function of frequency. The results of the models differed from each other already with frequency of order 5 Hz, while the time constant for the relaxation, obtained from steady-state distribution calculation, would have implied significant differences appear not until with frequency of order 50 Hz.

  9. CFD modeling of commercial-scale entrained-flow coal gasifiers

    SciTech Connect (OSTI)

    Ma, J.; Zitney, S.

    2012-01-01

    Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. Computational fluid dynamics (CFD) has been used to model the turbulent multiphase reacting flow inside commercial-scale entrained-flow coal gasifiers. Due to the complexity of the physical and chemical processes involved, the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented in this paper include a moisture vaporization model with consideration of high mass transfer rate and a coal devolatilization model with more species to represent coal volatiles and the heating rate effect on volatile yield. The global gas phase reaction kinetics is also carefully selected. To predict a reasonable peak temperature of the coal/O{sub 2} flame inside an entrained-flow gasifier, the reserve reaction of H{sub 2} oxidation is included in the gas phase reaction model. The enhanced CFD model is applied to simulate two typical commercial-scale oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here

  10. Comparative analysis for various redox flow batteries chemistries using a cost performance model

    SciTech Connect (OSTI)

    Crawford, Aladsair J.; Viswanathan, Vilayanur V.; Stephenson, David E.; Wang, Wei; Thomsen, Edwin C.; Reed, David M.; Li, Bin; Balducci, Patrick J.; Kintner-Meyer, Michael CW; Sprenkle, Vincent L.

    2015-10-20

    A robust performance-based cost model is developed for all-vanadium, iron-vanadium and iron chromium redox flow batteries. Systems aspects such as shunt current losses, pumping losses and thermal management are accounted for. The objective function, set to minimize system cost, allows determination of stack design and operating parameters such as current density, flow rate and depth of discharge (DOD). Component costs obtained from vendors are used to calculate system costs for various time frames. A 2 kW stack data was used to estimate unit energy costs and compared with model estimates for the same size electrodes. The tool has been shared with the redox flow battery community to both validate their stack data and guide future direction.

  11. Evaluation of Pre- and Post-Redevelopment Groundwater Chemical Analyses

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    from LM Monitoring Wells | Department of Energy Evaluation of Pre- and Post-Redevelopment Groundwater Chemical Analyses from LM Monitoring Wells Evaluation of Pre- and Post-Redevelopment Groundwater Chemical Analyses from LM Monitoring Wells AS&T Ancillary Work Plan (AWP) Final Well Redevelopment Evaluation Report Evaluation of Pre- and Post-Redevelopment Groundwater Chemical Analyses from LM Monitoring Wells (3.25 MB) More Documents & Publications Analysis and Geochemical Modeling

  12. Self-sustaining turbulence in a restricted nonlinear model of plane Couette flow

    SciTech Connect (OSTI)

    Thomas, Vaughan L.; Gayme, Dennice F.; Lieu, Binh K.; Jovanović, Mihailo R.; Farrell, Brian F.; Ioannou, Petros J.

    2014-10-15

    This paper demonstrates the maintenance of self-sustaining turbulence in a restricted nonlinear (RNL) model of plane Couette flow. The RNL system is derived directly from the Navier-Stokes equations and permits higher resolution studies of the dynamical system associated with the stochastic structural stability theory (S3T) model, which is a second order approximation of the statistical state dynamics of the flow. The RNL model shares the dynamical restrictions of the S3T model but can be easily implemented by reducing a DNS code so that it retains only the RNL dynamics. Comparisons of turbulence arising from DNS and RNL simulations demonstrate that the RNL system supports self-sustaining turbulence with a mean flow as well as structural and dynamical features that are consistent with DNS. These results demonstrate that the simplified RNL system captures fundamental aspects of fully developed turbulence in wall-bounded shear flows and motivate use of the RNL/S3T framework for further study of wall-turbulence.

  13. Variable Density Flow Modeling for Simulation Framework for Regional Geologic CO{sub 2} Storage Along Arches Province of Midwestern United States

    SciTech Connect (OSTI)

    Joel Sminchak

    2011-09-30

    The Arches Province in the Midwestern U.S. has been identified as a major area for carbon dioxide (CO{sub 2}) storage applications because of the intersection of Mt. Simon sandstone reservoir thickness and permeability. To better understand large-scale CO{sub 2} storage infrastructure requirements in the Arches Province, variable density scoping level modeling was completed. Three main tasks were completed for the variable density modeling: Single-phase, variable density groundwater flow modeling; Scoping level multi-phase simulations; and Preliminary basin-scale multi-phase simulations. The variable density modeling task was successful in evaluating appropriate input data for the Arches Province numerical simulations. Data from the geocellular model developed earlier in the project were translated into preliminary numerical models. These models were calibrated to observed conditions in the Mt. Simon, suggesting a suitable geologic depiction of the system. The initial models were used to assess boundary conditions, calibrate to reservoir conditions, examine grid dimensions, evaluate upscaling items, and develop regional storage field scenarios. The task also provided practical information on items related to CO{sub 2} storage applications in the Arches Province such as pressure buildup estimates, well spacing limitations, and injection field arrangements. The Arches Simulation project is a three-year effort and part of the United States Department of Energy (U.S. DOE)/National Energy Technology Laboratory (NETL) program on innovative and advanced technologies and protocols for monitoring/verification/accounting (MVA), simulation, and risk assessment of CO{sub 2} sequestration in geologic formations. The overall objective of the project is to develop a simulation framework for regional geologic CO{sub 2} storage infrastructure along the Arches Province of the Midwestern U.S.

  14. A Lattice Boltzmann Fictitious Domain Method for Modeling Red Blood Cell Deformation and Multiple-Cell Hydrodynamic Interactions in Flow

    SciTech Connect (OSTI)

    Shi, Xing; Lin, Guang; Zou, Jianfeng; Fedosov, Dmitry A.

    2013-07-20

    To model red blood cell (RBC) deformation in flow, the recently developed LBM-DLM/FD method ([Shi and Lim, 2007)29], derived from the lattice Boltzmann method and the distributed Lagrange multiplier/fictitious domain methodthe fictitious domain method, is extended to employ the mesoscopic network model for simulations of red blood cell deformation. The flow is simulated by the lattice Boltzmann method with an external force, while the network model is used for modeling red blood cell deformation and the fluid-RBC interaction is enforced by the Lagrange multiplier. To validate parameters of the RBC network model, sThe stretching numerical tests on both coarse and fine meshes are performed and compared with the corresponding experimental data to validate the parameters of the RBC network model. In addition, RBC deformation in pipe flow and in shear flow is simulated, revealing the capacity of the current method for modeling RBC deformation in various flows.

  15. Development of Mechanistic Modeling Capabilities for Local Neutronically-Coupled Flow-Induced Instabilities in Advanced Water-Cooled Reactors

    SciTech Connect (OSTI)

    Michael Podowski

    2009-11-30

    The major research objectives of this project included the formulation of flow and heat transfer modeling framework for the analysis of flow-induced instabilities in advanced light water nuclear reactors such as boiling water reactors. General multifield model of two-phase flow, including the necessary closure laws. Development of neurton kinetics models compatible with the proposed models of heated channel dynamics. Formulation and encoding of complete coupled neutronics/thermal-hydraulics models for the analysis of spatially-dependent local core instabilities. Computer simulations aimed at testing and validating the new models of reactor dynamics.

  16. Aviation security cargo inspection queuing simulation model for material flow and accountability

    SciTech Connect (OSTI)

    Olama, Mohammed M; Allgood, Glenn O; Rose, Terri A; Brumback, Daryl L

    2009-01-01

    Beginning in 2010, the U.S. will require that all cargo loaded in passenger aircraft be inspected. This will require more efficient processing of cargo and will have a significant impact on the inspection protocols and business practices of government agencies and the airlines. In this paper, we develop an aviation security cargo inspection queuing simulation model for material flow and accountability that will allow cargo managers to conduct impact studies of current and proposed business practices as they relate to inspection procedures, material flow, and accountability.

  17. The Sim-SEQ Project: Comparison of Selected Flow Models for the S-3 Site

    SciTech Connect (OSTI)

    Mukhopadhyay, Sumit; Doughty, Christine A.; Bacon, Diana H.; Li, Jun; Wei, Lingli; Yamamoto, Hajime; Gasda, Sarah E.; Hosseini, Seyyed; Nicot, Jean-Philippe; Birkholzer, Jens

    2015-05-23

    Sim-SEQ is an international initiative on model comparison for geologic carbon sequestration, with an objective to understand and, if possible, quantify model uncertainties. Model comparison efforts in Sim-SEQ are at present focusing on one specific field test site, hereafter referred to as the Sim-SEQ Study site (or S-3 site). Within Sim-SEQ, different modeling teams are developing conceptual models of CO2 injection at the S-3 site. In this paper, we select five flow models of the S-3 site and provide a qualitative comparison of their attributes and predictions. These models are based on five different simulators or modeling approaches: TOUGH2/EOS7C, STOMP-CO2e, MoReS, TOUGH2-MP/ECO2N, and VESA. In addition to model-to-model comparison, we perform a limited model-to-data comparison, and illustrate how model choices impact model predictions. We conclude the paper by making recommendations for model refinement that are likely to result in less uncertainty in model predictions.

  18. F-Area Acid/Caustic Basin groundwater monitoring report

    SciTech Connect (OSTI)

    Thompson, C.Y.

    1992-03-01

    This progress report for fourth quarter 1991 and 1992 summary from the Savannah River Plant includes discussion on the following topics: groundwater monitoring data; analytical results exceeding standards; upgradient versus downgradient results; turbidity results exceeding standards; water elevations, flow directions, and flow rates.

  19. Natural radionuclides in groundwaters

    SciTech Connect (OSTI)

    Laul, J.C.

    1990-01-01

    The U-234 and Th-230 radionuclides are highly retarded by factors of 10{sup 4} to 10{sup 5} in basalt groundwater (Hanford) and briny groundwaters from Texas and geothermal brine from the Salton Sea Geothermal Field (SSGF). In basalt groundwaters (low ionic strength), Ra is highly sorbed, while in brines (high ionic strength), Ra is soluble. This is probably because the sorption sites are saturated with Na{sup +} and Cl{sup {minus}} ions and RaCl{sub 2} is soluble in brines. Pb-210 is soluble in SSGF brine, probably as a chloride complex. The U-234/Th-230 ratios in basalt groundwaters and brines from Texas and SSGF are nearly unity, indicating that U is in the +4 state, suggesting a reducing environment for these aquifers. 19 refs., 3 figs.

  20. Experimental Modeling of VHTR Plenum Flows during Normal Operation and Pressurized Conduction Cooldown

    SciTech Connect (OSTI)

    Glenn E McCreery; Keith G Condie

    2006-09-01

    The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. The present document addresses experimental modeling of flow and thermal mixing phenomena of importance during normal or reduced power operation and during a loss of forced reactor cooling (pressurized conduction cooldown) scenario. The objectives of the experiments are, 1), provide benchmark data for assessment and improvement of codes proposed for NGNP designs and safety studies, and, 2), obtain a better understanding of related phenomena, behavior and needs. Physical models of VHTR vessel upper and lower plenums which use various working fluids to scale phenomena of interest are described. The models may be used to both simulate natural convection conditions during pressurized conduction cooldown and turbulent lower plenum flow during normal or reduced power operation.

  1. The effects of parameter variation on MSET models of the Crystal River-3 feedwater flow system.

    SciTech Connect (OSTI)

    Miron, A.

    1998-04-01

    In this paper we develop further the results reported in Reference 1 to include a systematic study of the effects of varying MSET models and model parameters for the Crystal River-3 (CR) feedwater flow system The study used archived CR process computer files from November 1-December 15, 1993 that were provided by Florida Power Corporation engineers Fairman Bockhorst and Brook Julias. The results support the conclusion that an optimal MSET model, properly trained and deriving its inputs in real-time from no more than 25 of the sensor signals normally provided to a PWR plant process computer, should be able to reliably detect anomalous variations in the feedwater flow venturis of less than 0.1% and in the absence of a venturi sensor signal should be able to generate a virtual signal that will be within 0.1% of the correct value of the missing signal.

  2. Numerical Simulation of Groundwater Withdrawal from Proposed Pumping Near the Southeastern Nevada Test Site

    SciTech Connect (OSTI)

    R.W.H. Carroll; R.L.Hershey; G.M. Pohll

    2006-04-25

    Current modeling of the southeastern portion of the Nevada Test Site (NTS) with a refined U.S. Geological Survey Death Valley regional groundwater flow system model shows that impacts from pumping by proposed Southern Nevada Water Authority (SNWA) and Vidler Water Company (VWC) wells can be substantial over 75 years of operation. Results suggest that significant drawdown at proposed well sites will occur with depths of drawdown ranging from 8 m to nearly 1,600 m. The areal extent of 0.5 m of drawdown is also significant, impacting Mercury Valley, Amargosa, Indian Springs, Three Lakes, and Frenchman Flat basins. Drawdown will impact Army No.1 Water Well in Mercury Valley by lowering water levels 2.1 m but will not impact other NTS production wells. It is also predicted that flowpaths from detonation sites within the NTS will be altered with the potential to move material out of the NTS. Impacts to both springs and regions of groundwater evapotranspiration (modeled as MODFLOW drain cells) appear very minimal, with an estimated 0.2-percent reduction in flow to these regions. This amounts to a loss of more that 55,000 m3/year (45 acre-ft/year), or more than 4,000,000 m3 (3,400 acre-ft) during 75 years of groundwater withdrawal by pumping at proposed SNWA and VWC wells. Whether the reduced flow will impact specific springs more than any others, or if the reduction in flow is enough to have significant ecological implications, was not addressed in this study.

  3. Three-dimensional modeling of diesel engine intake flow, combustion and emissions-II

    SciTech Connect (OSTI)

    Reitz, R.D.; Rutland, C.J.

    1993-09-01

    A three-dimensional computer code, KIVA, is being modified to include state-of-the-art submodels for diesel engine flow and combustion. Improved and/or new submodels which have already been implemented and previously reported are: Wall heat transfer with unsteadiness and compressibility, laminar-turbulent characteristic time combustion with unburned HC and Zeldo`vich NO{sub x}, and spray/wall impingement with rebounding and sliding drops. Progress on the implementation of improved spray drop drag and drop breakup models, the formulation and testing of a multistep kinetics ignition model and preliminary soot modeling results are described in this report. In addition, the use of a block structured version of KIVA to model the intake flow process is described. A grid generation scheme has been developed for modeling realistic (complex) engine geometries, and computations have been made of intake flow in the ports and combustion chamber of a two-intake-valve engine. The research also involves the use of the code to assess the effects of subprocesses on diesel engine performance. The accuracy of the predictions is being tested by comparisons with engine experiments. To date, comparisons have been made with measured engine cylinder pressure, temperature and heat flux data, and the model results are in good agreement with the experiments. Work is in progress that will allow validation of in-cylinder flow and soot formation predictions. An engine test facility is described that is being used to provide the needed validation data. Test results have been obtained showing the effect of injection rate and split injections on engine performance and emissions.

  4. Development of an entrained flow gasifier model for process optimization study

    SciTech Connect (OSTI)

    Biagini, E.; Bardi, A.; Pannocchia, G.; Tognotti, L.

    2009-10-15

    Coal gasification is a versatile process to convert a solid fuel in syngas, which can be further converted and separated in hydrogen, which is a valuable and environmentally acceptable energy carrier. Different technologies (fixed beds, fluidized beds, entrained flow reactors) are used, operating under different conditions of temperature, pressure, and residence time. Process studies should be performed for defining the best plant configurations and operating conditions. Although 'gasification models' can be found in the literature simulating equilibrium reactors, a more detailed approach is required for process analysis and optimization procedures. In this work, a gasifier model is developed by using AspenPlus as a tool to be implemented in a comprehensive process model for the production of hydrogen via coal gasification. It is developed as a multizonal model by interconnecting each step of gasification (preheating, devolatilization, combustion, gasification, quench) according to the reactor configuration, that is in entrained flow reactor. The model removes the hypothesis of equilibrium by introducing the kinetics of all steps and solves the heat balance by relating the gasification temperature to the operating conditions. The model allows to predict the syngas composition as well as quantity the heat recovery (for calculating the plant efficiency), 'byproducts', and residual char. Finally, in view of future works, the development of a 'gasifier model' instead of a 'gasification model' will allow different reactor configurations to be compared.

  5. Unsteady flow model of Priest Rapids Dam releases at Hanford Reach, Columbia River, Washington

    SciTech Connect (OSTI)

    Sneider, S.C.; Skaggs, R.L.

    1983-02-01

    A model was developed to simulate water levels at three locations on the Columbia River between Priest Rapids Dam River Mile 396.1 (River Kilometer 639.0) and River Mile 361.50 (River Kilometer 581.7). The model was calibrated and verified over a range of flows. The results of calibration and verification indicate that the model, with reasonable accuracy, simulates stages to within +-0.08 m (+- 0.25 ft) and surface wave timing to within +-20 min. The model can be used by researchers, river system managers, planners, and decision makers as a tool to predict fluctuating water levels at locations downstream of dams. Data produced by the model can be used to evaluate and quantify possible impacts on aquatic organisms, water supply, navigation, irrigation, recreation, and additional hydropower enhancement. Although the results of this model calibrationand the model simulations presented are site-specific, the methodology is generic. Therefore, the model can be adapted to reflect dam discharges and resulting river flows at other river systems affected by water-level fluctuations.

  6. DENSE MULTIPHASE FLOW SIMULATION: CONTINUUM MODEL FOR POLY-DISPERSED SYSTEMS USING KINETIC THEORY

    SciTech Connect (OSTI)

    Moses Bogere

    2011-08-31

    The overall objective of the project was to verify the applicability of the FCMOM approach to the kinetic equations describing the particle flow dynamics. For monodispersed systems the fundamental equation governing the particle flow dynamics is the Boltzmann equation. During the project, the FCMOM was successfully applied to several homogeneous and in-homogeneous problems in different flow regimes, demonstrating that the FCMOM has the potential to be used to solve efficiently the Boltzmann equation. However, some relevant issues still need to be resolved, i.e. the homogeneous cooling problem (inelastic particles cases) and the transition between different regimes. In this report, the results obtained in homogeneous conditions are discussed first. Then a discussion of the validation results for in-homogeneous conditions is provided. And finally, a discussion will be provided about the transition between different regimes. Alongside the work on development of FCMOM approach studies were undertaken in order to provide insights into anisotropy or particles kinetics in riser hydrodynamics. This report includes results of studies of multiphase flow with unequal granular temperatures and analysis of momentum re-distribution in risers due to particle-particle and fluid-particle interactions. The study of multiphase flow with unequal granular temperatures entailed both simulation and experimental studies of two particles sizes in a riser and, a brief discussion of what was accomplished will be provided. And finally, a discussion of the analysis done on momentum re-distribution of gas-particles flow in risers will be provided. In particular a discussion of the remaining work needed in order to improve accuracy and predictability of riser hydrodynamics based on two-fluid models and how they can be used to model segregation in risers.

  7. A MILP-Based Distribution Optimal Power Flow Model for Microgrid Operation

    SciTech Connect (OSTI)

    Liu, Guodong; Starke, Michael R; Zhang, Xiaohu; Tomsovic, Kevin

    2016-01-01

    This paper proposes a distribution optimal power flow (D-OPF) model for the operation of microgrids. The proposed model minimizes not only the operating cost, including fuel cost, purchasing cost and demand charge, but also several performance indices, including voltage deviation, network power loss and power factor. It co-optimizes the real and reactive power form distributed generators (DGs) and batteries considering their capacity and power factor limits. The D-OPF is formulated as a mixed-integer linear programming (MILP). Numerical simulation results show the effectiveness of the proposed model.

  8. An investigation of a model of the flow pattern transition mechanism in relation to the identification of annular flow of R134a in a vertical tube using various void fraction models and flow regime maps

    SciTech Connect (OSTI)

    Dalkilic, A.S. [Heat and Thermodynamics Division, Department of Mechanical Engineering, Yildiz Technical University, Yildiz, Besiktas, Istanbul 34349 (Turkey); Wongwises, S. [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

    2010-09-15

    In the present study, new experimental data are presented for literature on the prediction of film thickness and identification of flow regime during the co-current downward condensation in a vertical smooth copper tube having an inner diameter of 8.1 mm and a length of 500 mm. R134a and water are used as working fluids in the tube side and annular side of a double tube heat exchanger, respectively. Condensation experiments are done at mass fluxes of 300 and 515 kg m{sup -2} s{sup -1}. The condensing temperatures are between 40 and 50 C; heat fluxes are between 12.65 and 66.61 kW m{sup -2}. The average experimental heat transfer coefficient of the refrigerant HFC-134a is calculated by applying an energy balance based on the energy transferred from the test section. A mathematical model by Barnea et al. based on the momentum balance of liquid and vapor phases is used to determine the condensation film thickness of R134a. The comparative film thickness values are determined indirectly using relevant measured data together with various void fraction models and correlations reported in the open literature. The effects of heat flux, mass flux, and condensation temperature on the film thickness and condensation heat transfer coefficient are also discussed for the laminar and turbulent flow conditions. There is a good agreement between the film thickness results obtained from the theoretical model and those obtained from six of 35 void fraction models in the high mass flux region of R134a. In spite of their different valid conditions, six well-known flow regime maps from the literature are found to be predictive for the annular flow conditions in the test tube in spite of their different operating conditions. (author)

  9. The shallow water equations as a hybrid flow model for the numerical and experimental analysis of hydro power stations

    SciTech Connect (OSTI)

    Ostermann, Lars; Seidel, Christian

    2015-03-10

    The numerical analysis of hydro power stations is an important method of the hydraulic design and is used for the development and optimisation of hydro power stations in addition to the experiments with the physical submodel of a full model in the hydraulic laboratory. For the numerical analysis, 2D and 3D models are appropriate and commonly used.The 2D models refer mainly to the shallow water equations (SWE), since for this flow model a large experience on a wide field of applications for the flow analysis of numerous problems in hydraulic engineering already exists. Often, the flow model is verified by in situ measurements. In order to consider 3D flow phenomena close to singularities like weirs, hydro power stations etc. the development of a hybrid fluid model is advantageous to improve the quality and significance of the global model. Here, an extended hybrid flow model based on the principle of the SWE is presented. The hybrid flow model directly links the numerical model with the experimental data, which may originate from physical full models, physical submodels and in-situ measurements. Hence a wide field of application of the hybrid model emerges including the improvement of numerical models and the strong coupling of numerical and experimental analysis.

  10. Temperature, humidity and air flow in the emplacement drifts using convection and dispersion transport models

    SciTech Connect (OSTI)

    Danko, G.; Birkholzer, J.T.; Bahrami, D.; Halecky, N.

    2009-10-01

    A coupled thermal-hydrologic-airflow model is developed, solving for the transport processes within a waste emplacement drift and the surrounding rockmass together at the proposed nuclear waste repository at Yucca Mountain. Natural, convective air flow as well as heat and mass transport in a representative emplacement drift during post-closure are explicitly simulated, using the MULTIFLUX model. The conjugate, thermal-hydrologic transport processes in the rockmass are solved with the TOUGH2 porous-media simulator in a coupled way to the in-drift processes. The new simulation results show that large-eddy turbulent flow, as opposed to small-eddy flow, dominate the drift air space for at least 5000 years following waste emplacement. The size of the largest, longitudinal eddy is equal to half of the drift length, providing a strong axial heat and moisture transport mechanism from the hot to the cold drift sections. The in-drift results are compared to those from simplified models using a surrogate, dispersive model with an equivalent dispersion coefficient for heat and moisture transport. Results from the explicit, convective velocity simulation model provide higher axial heat and moisture fluxes than those estimated from the previously published, simpler, equivalent-dispersion models, in addition to showing differences in temperature, humidity and condensation rate distributions along the drift length. A new dispersive model is also formulated, giving a time- and location-variable function that runs generally about ten times higher in value than the highest dispersion coefficient currently used in the Yucca Mountain Project as an estimate for the equivalent dispersion coefficient in the emplacement drift. The new dispersion coefficient variation, back-calculated from the convective model, can adequately describe the heat and mass transport processes in the emplacement drift example.

  11. User's manual for the Sandia Waste-Isolation Flow and Transport model (SWIFT).

    SciTech Connect (OSTI)

    Reeves, Mark; Cranwell, Robert M.

    1981-11-01

    This report describes a three-dimensional finite-difference model (SWIFT) which is used to simulate flow and transport processes in geologic media. The model was developed for use by the Nuclear Regulatory Commission in the analysis of deep geologic nuclear waste-disposal facilities. This document, as indicated by the title, is a user's manual and is intended to facilitate the use of the SWIFT simulator. Mathematical equations, submodels, application notes, and a description of the program itself are given herein. In addition, a complete input data guide is given along with several appendices which are helpful in setting up a data-input deck. Computer code SWIFT (Sandia Waste Isolation, Flow and Transport Model) is a fully transient, three-dimensional model which solves the coupled equations for transport in geologic media. The processes considered are: (1) fluid flow; (2) heat transport; (3) dominant-species miscible displacement; and (4) trace-species miscible displacement. The first three processes are coupled via fluid density and viscosity. Together they provide the velocity field on which the fourth process depends.

  12. MODELING COUPLED PROCESSES OF MULTIPHASE FLOW AND HEAT TRANSFER IN UNSATURATED FRACTURED ROCK

    SciTech Connect (OSTI)

    Y. Wu; S. Mukhopadhyay; K. Zhang; G.S. Bodvarsson

    2006-02-28

    A mountain-scale, thermal-hydrologic (TH) numerical model is developed for investigating unsaturated flow behavior in response to decay heat from the radioactive waste repository at Yucca Mountain, Nevada, USA. The TH model, consisting of three-dimensional (3-D) representations of the unsaturated zone, is based on the current repository design, drift layout, and thermal loading scenario under estimated current and future climate conditions. More specifically, the TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the most updated, best-estimated input parameters. This mountain-scale TH model simulates the coupled TH processes related to mountain-scale multiphase fluid flow, and evaluates the impact of radioactive waste heat on the hydrogeological system, including thermally perturbed liquid saturation, gas- and liquid-phase fluxes, and water and rock temperature elevations, as well as the changes in water flux driven by evaporation/condensation processes and drainage between drifts. For a better description of the ambient geothermal condition of the unsaturated zone system, the TH model is first calibrated against measured borehole temperature data. The ambient temperature calibration provides the necessary surface and water table boundary as well as initial conditions. Then, the TH model is used to obtain scientific understanding of TH processes in the Yucca Mountain unsaturated zone under the designed schedule of repository thermal load.

  13. Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow

    SciTech Connect (OSTI)

    Donna Post Guillen

    2009-07-01

    A hydrodynamic model of two-phase, churn-turbulent flows is being developed using the computational multiphase fluid dynamics (CMFD) code, NPHASE-CMFD. The numerical solutions obtained by this model are compared with experimental data obtained at the TOPFLOW facility of the Institute of Safety Research at the Forschungszentrum Dresden-Rossendorf. The TOPFLOW data is a high quality experimental database of upward, co-current air-water flows in a vertical pipe suitable for validation of computational fluid dynamics (CFD) codes. A five-field CMFD model was developed for the continuous liquid phase and four bubble size groups using mechanistic closure models for the ensemble-averaged Navier-Stokes equations. Mechanistic models for the drag and non-drag interfacial forces are implemented to include the governing physics to describe the hydrodynamic forces controlling the gas distribution. The closure models provide the functional form of the interfacial forces, with user defined coefficients to adjust the force magnitude. An optimization strategy was devised for these coefficients using commercial design optimization software. This paper demonstrates an approach to optimizing CMFD model parameters using a design optimization approach. Computed radial void fraction profiles predicted by the NPHASE-CMFD code are compared to experimental data for four bubble size groups.

  14. Modeling of dissociation and energy transfer in shock-heated nitrogen flows

    SciTech Connect (OSTI)

    Munafò, A.; Liu, Y.; Panesi, M.

    2015-12-15

    This work addresses the modeling of dissociation and energy transfer processes in shock heated nitrogen flows by means of the maximum entropy linear model and a newly proposed hybrid bin vibrational collisional model. Both models aim at overcoming two of the main limitations of the state of the art non-equilibrium models: (i) the assumption of equilibrium between rotational and translational energy modes of the molecules and (ii) the reliance on the quasi-steady-state distribution for the description of the population of the internal levels. The formulation of the coarse-grained models is based on grouping the energy levels into bins, where the population is assumed to follow a Maxwell-Boltzmann distribution at its own temperature. Different grouping strategies are investigated. Following the maximum entropy principle, the governing equations are obtained by taking the zeroth and first-order moments of the rovibrational master equations. The accuracy of the proposed models is tested against the rovibrational master equation solution for both flow quantities and population distributions. Calculations performed for free-stream velocities ranging from 5 km/s to 10 km/s demonstrate that dissociation can be accurately predicted by using only 2-3 bins. It is also shown that a multi-temperature approach leads to an under-prediction of dissociation, due to the inability of the former to account for the faster excitation of high-lying vibrational states.

  15. Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling

    SciTech Connect (OSTI)

    Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.

    2009-01-15

    A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.

  16. Nevada National Security Site Groundwater Program Welcomes Peer Review Team

    Office of Energy Efficiency and Renewable Energy (EERE)

    Recently, an independent peer review team was invited to assess the groundwater characterization program at the Nevada National Security Site (NNSS). This nationally recognized group of experts, from various external organizations, will examine the computer modeling approach developed to better understand how historic underground nuclear testing in Yucca Flat affected the groundwater.

  17. Underground Test Area Subproject Phase I Data Analysis Task. Volume III - Groundwater Recharge and Discharge Data Documentation Package

    SciTech Connect (OSTI)

    1996-10-01

    Volume III of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the data covering groundwater recharge and discharge. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  18. Entropy analysis on non-equilibrium two-phase flow models

    SciTech Connect (OSTI)

    Karwat, H.; Ruan, Y.Q.

    1995-09-01

    A method of entropy analysis according to the second law of thermodynamics is proposed for the assessment of a class of practical non-equilibrium two-phase flow models. Entropy conditions are derived directly from a local instantaneous formulation for an arbitrary control volume of a structural two-phase fluid, which are finally expressed in terms of the averaged thermodynamic independent variables and their time derivatives as well as the boundary conditions for the volume. On the basis of a widely used thermal-hydraulic system code it is demonstrated with practical examples that entropy production rates in control volumes can be numerically quantified by using the data from the output data files. Entropy analysis using the proposed method is useful in identifying some potential problems in two-phase flow models and predictions as well as in studying the effects of some free parameters in closure relationships.

  19. KIVA--Hydrodynamics Model for Chemically Reacting Flow with Spray - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Innovation Portal Vehicles and Fuels Vehicles and Fuels Industrial Technologies Industrial Technologies Energy Analysis Energy Analysis Find More Like This Return to Search KIVA--Hydrodynamics Model for Chemically Reacting Flow with Spray Los Alamos National Laboratory Contact LANL About This Technology Simulation of an experimental engine with DOHC quasi-symmetric pent-roof combustion chamber and 4 valves. Simulation of an experimental engine with DOHC quasi-symmetric pent-roof combustion

  20. ANALYSIS OF TWO-PHASE FLOW MODELS WITH TWO MOMENTUM EQUATIONS.

    SciTech Connect (OSTI)

    KROSHILIN,A.E.KROSHILIN,V.E.KOHUT,P.

    2004-03-15

    An analysis of the standard system of differential equations describing multi-speed flows of multi-phase media is performed. It is proved that the Cauchy problem, as posed in most best-estimate thermal-hydraulic codes, results in unstable solutions and potentially unreliable description of many physical phenomena. A system of equations, free from instability effects, is developed allowing more rigorous numerical modeling.

  1. Modeling of Gas-Liquid Flow Through An Interconnected Channel Matrix

    SciTech Connect (OSTI)

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane.H

    2009-01-01

    The motion of a less viscous, non-wetting gas into a liquid-saturated porous medium is known as drainage. Drainage is an important process in environmental applications, such as enhanced oil recovery and geologic CO2 sequestration. Understanding what conditions will increase the volume of gas that can saturate an initially water-saturated porous medium is of importance for predictions of the total CO2 volume that can be sequestered in known geologic formations. To further the understanding of how drainage flow properties are related to different injection flow-rates, a porous medium consisting of interconnected channels and pores was manufactured to perform bench-top experiments of drainage. Additionally, a finite-volume model of this interconnected channel matrix was constructed. Numerical simulations of constant-rate injection into the model porous medium are first shown to compare favorably to the bench-top experiments. The fluid and injection properties of the drainage process were then varied to evaluate the flow conditions which would maximize the volume of gas trapped within the porous medium. In particular, CO2 displacing brine within the porous medium was modeled, with representative subsurface temperatures and fluid properties. It was shown with these fluid conditions a higher final saturation of the invading less-viscous CO2 was obtained, as compared to air into water experiments at similar injection rates.

  2. Multiphase flow and multicomponent reactive transport model of the ventilation experiment in Opalinus clay

    SciTech Connect (OSTI)

    Zheng, L.; Samper, J.; Montenegro, L.; Major, J.C.

    2008-10-15

    During the construction and operational phases of a high-level radioactive waste (HLW) repository constructed in a clay formation, ventilation of underground drifts will cause desaturation and oxidation of the rock. The Ventilation Experiment (VE) was performed in a 1.3 m diameter unlined horizontal microtunnel on Opalinus clay at Mont Terri underground research laboratory in Switzerland to evaluate the impact of desaturation on rock properties. A multiphase flow and reactive transport model of VE is presented here. The model accounts for liquid, vapor and air flow, evaporation/condensation and multicomponent reactive solute transport with kinetic dissolution of pyrite and siderite and local-equilibrium dissolution/precipitation of calcite, ferrihydrite, dolomite, gypsum and quartz. Model results reproduce measured vapor flow, liquid pressure and hydrochemical data and capture the trends of measured relative humidities, although such data are slightly overestimated near the rock interface due to uncertainties in the turbulence factor. Rock desaturation allows oxygen to diffuse into the rock and triggers pyrite oxidation, dissolution of calcite and siderite, precipitation of ferrihydrite, dolomite and gypsum and cation exchange. pH in the unsaturated rock varies from 7.8 to 8 and is buffered by calcite. Computed changes in the porosity and the permeability of Opalinus clay in the unsaturated zone caused by oxidation and mineral dissolution/precipitation are smaller than 5%. Therefore, rock properties are not expected to be affected significantly by ventilation of underground drifts during construction and operational phases of a HLW repository in clay.

  3. A Nonlocal Peridynamic Plasticity Model for the Dynamic Flow and Fracture of Concrete.

    SciTech Connect (OSTI)

    Vogler, Tracy; Lammi, Christopher James

    2014-10-01

    A nonlocal, ordinary peridynamic constitutive model is formulated to numerically simulate the pressure-dependent flow and fracture of heterogeneous, quasi-brittle ma- terials, such as concrete. Classical mechanics and traditional computational modeling methods do not accurately model the distributed fracture observed within this family of materials. The peridynamic horizon, or range of influence, provides a characteristic length to the continuum and limits localization of fracture. Scaling laws are derived to relate the parameters of peridynamic constitutive model to the parameters of the classical Drucker-Prager plasticity model. Thermodynamic analysis of associated and non-associated plastic flow is performed. An implicit integration algorithm is formu- lated to calculate the accumulated plastic bond extension and force state. The gov- erning equations are linearized and the simulation of the quasi-static compression of a cylinder is compared to the classical theory. A dissipation-based peridynamic bond failure criteria is implemented to model fracture and the splitting of a concrete cylinder is numerically simulated. Finally, calculation of the impact and spallation of a con- crete structure is performed to assess the suitability of the material and failure models for simulating concrete during dynamic loadings. The peridynamic model is found to accurately simulate the inelastic deformation and fracture behavior of concrete during compression, splitting, and dynamically induced spall. The work expands the types of materials that can be modeled using peridynamics. A multi-scale methodology for simulating concrete to be used in conjunction with the plasticity model is presented. The work was funded by LDRD 158806.

  4. New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes

    SciTech Connect (OSTI)

    Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X.; Wang, S.

    2014-01-29

    Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction.

  5. Paddy field, groundwater and land subsidence

    SciTech Connect (OSTI)

    Wen, L.J.

    1995-12-31

    Through many years of research and technical interchange both at home and abroad, it is commonly recognized that paddy fields possess the functions of micro-climate adjustment, flood detection and prevention, soil and water conservation, river-flow stabilization, soil salinization prevention, water purification, groundwater recharge, rural area beautification and environmental protection which are all beneficial to the public. In recent years, the global environmental problems have become a series concern throughout the world. These include the broken ozone layer, green house effects, acid rain, land desertion, tropical rain forest disappearing etc. Among them, rain forest disappearing draws great attention. Both rain forests and paddy fields are in tropical areas. They have similar functions and are disappearing because of economic pressure. This paper describes the special functions of paddy fields on water purification, ground water recharge and prevention of land subsidence, and reiterates groundwater utilization and land subsidence prevention measures. In view of the importance of groundwater resources, paddy fields, which can not be replaced by any other artificial groundwater recharge facilities, should not be reduced in acreage, nor can they be left idle. Paddy fields shall be properly maintained and managed in order to strengthen their special functions in the years to come even under heavy pressure from foreign countries.

  6. Fernald Environmental Management Project Archived Soil & Groundwater...

    Office of Environmental Management (EM)

    Fernald Environmental Management Project Archived Soil & Groundwater Master Reports Fernald Environmental Management Project Archived Soil & Groundwater Master Reports Fernald ...

  7. Miamisburg Environmental Management Project Archived Soil & Groundwate...

    Office of Environmental Management (EM)

    Miamisburg Environmental Management Project Archived Soil & Groundwater Master Reports Miamisburg Environmental Management Project Archived Soil & Groundwater Master Reports ...

  8. Finite-Element Modeling of Electrostatic Sensors for the Flow Measurement of Particles in Pneumatic Pipelines

    SciTech Connect (OSTI)

    Krabicka, J.; Yan, Y.

    2009-08-15

    Electrostatic sensors are used in certain industries for the flow measurement of pneumatically conveyed solids. However, despite various advances that have been made in recent years, relatively little information is known about the exact nature of the electrostatic charge induced onto the sensor electrode due to moving particles, which is dependent on electrode geometry, particle distribution, and particle velocity. This paper presents a novel approach to the study of the charge induced onto electrostatic sensors based on fitting a Lorentzian curve to the results of a finite-element model of the electrostatic sensor and pipeline. The modeling method is validated by comparing the modeling results of a nonintrusive circular electrode with an established analytical solution. The modeling results are used for in-depth analysis and informed design of a particular sensor configuration.

  9. A simple model for a zinc/bromine flow cell and associated storage tanks

    SciTech Connect (OSTI)

    Simpson, G.D.; White, R.E. . Dept. of Chemical Engineering)

    1990-06-01

    A simple model for a parallel plate, zinc/bromine flow cell and associated storage tanks is presented and used to make time-dependent predictions for various quantities in the system. The model is based on a previously published algebraic model of the cell at steady-state and time-dependent, first-order differential equations for the storage tanks. The Butler--Volmer equation is used for the electrochemical reactions, and the homogeneous reaction between bromine and bromide is included. The model predictions indicate that the charging operation of a zinc/bromine battery can be significantly improved by using a storage tank with a larger residence time for the bromine side of the system.

  10. Protection of the Groundwater Resource

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Protection of the Groundwater Resource Protection of the Groundwater Resource Monitoring wells act as sentinels between suspected LANL contamination and the water supply. August 1, 2013 Where to place a sentinel well Where

  11. Modeling dynamic stall on wind turbine blades under rotationally augmented flow fields

    SciTech Connect (OSTI)

    Guntur, S.; Schreck, S.; Sorensen, N. N.; Bergami, L.

    2015-04-22

    It is well known that airfoils under unsteady flow conditions with a periodically varying angle of attack exhibit aerodynamic characteristics different from those under steady flow conditions, a phenomenon commonly known as dynamic stall. It is also well known that the steady aerodynamic characteristics of airfoils in the inboard region of a rotating blade differ from those under steady two-dimensional (2D) flow conditions, a phenomenon commonly known as rotational augmentation. This paper presents an investigation of these two phenomena together in the inboard parts of wind turbine blades. This analysis is carried out using data from three sources: (1) the National Renewable Energy Laboratory’s Unsteady Aerodynamics Experiment Phase VI experimental data, including constant as well as continuously pitching blade conditions during axial operation, (2) data from unsteady Delayed Detached Eddy Simulations (DDES) carried out using the Technical University of Denmark’s in-house flow solver Ellipsys3D, and (3) data from a simplified model based on the blade element momentum method with a dynamic stall subroutine that uses rotationally augmented steady-state polars obtained from steady Phase VI experimental sequences, instead of the traditional 2D nonrotating data. The aim of this work is twofold. First, the blade loads estimated by the DDES simulations are compared to three select cases of the N sequence experimental data, which serves as a validation of the DDES method. Results show reasonable agreement between the two data in two out of three cases studied. Second, the dynamic time series of the lift and the moment polars obtained from the experiments are compared to those from the dynamic stall subroutine that uses the rotationally augmented steady polars. This allowed the differences between the stall phenomenon on the inboard parts of harmonically pitching blades on a rotating wind turbine and the classic dynamic stall representation in 2D flow to be

  12. The Convergence of Heat, Groundwater & Fracture Permeability. Innovative

    Office of Scientific and Technical Information (OSTI)

    Play Fairway Modelling Applied to the Tularosa Basin Phase 1 Project Report (Other) | SciTech Connect Other: The Convergence of Heat, Groundwater & Fracture Permeability. Innovative Play Fairway Modelling Applied to the Tularosa Basin Phase 1 Project Report Citation Details In-Document Search Title: The Convergence of Heat, Groundwater & Fracture Permeability. Innovative Play Fairway Modelling Applied to the Tularosa Basin Phase 1 Project Report This report summarizes the activities

  13. Final Report - Advanced Conceptual Models for Unsaturated and Two-Phase Flow in Fractured Rock

    SciTech Connect (OSTI)

    Nicholl, Michael J.

    2006-07-10

    The Department of Energy Environmental Management Program is faced with two major issues involving two-phase flow in fractured rock; specifically, transport of dissolved contaminants in the Vadose Zone, and the fate of Dense Nonaqueous Phase Liquids (DNAPLs) below the water table. Conceptual models currently used to address these problems do not correctly include the influence of the fractures, thus leading to erroneous predictions. Recent work has shown that it is crucial to understand the topology, or ''structure'' of the fluid phases (air/water or water/DNAPL) within the subsurface. It has also been shown that even under steady boundary conditions, the influence of fractures can lead to complex and dynamic phase structure that controls system behavior, with or without the presence of a porous rock matrix. Complicated phase structures within the fracture network can facilitate rapid transport, and lead to a sparsely populated and widespread distribution of concentrated contaminants; these qualities are highly difficult to describe with current conceptual models. The focus of our work is to improve predictive modeling through the development of advanced conceptual models for two-phase flow in fractured rock.

  14. Coupled reactive mass transport and fluid flow: Issues in model verification

    SciTech Connect (OSTI)

    Freedman, Vicky L.; Ibaraki, Motomu

    2003-01-03

    Model verification and validation are both important steps in the development of reactive transport models. In this paper, a distinction is made between verification and validation, and the focus is on codifying the issues of verification for a numerical, reactive transport flow model. First, the conceptual basis of model verification is reviewed, which shows that verification should be understood as a first step in model development, and be followed by a protocol that assures that the model accurately represents system behavior. Second, commonly used procedures and methods of model verification are presented. In the third part of this paper, an intercomparison of models is used to demonstrate that model verification can be performed despite differences in hydrogeochemical transport code formulations. Results of an example simulation of transport are presented in which the numerical model is tested against other hydrogeochemical codes. Different kinetic formulations between solid and aqueous phases used among numerical models complicates model verification. This test problem involves uranium transport under conditions of varying pH and oxidation potential, with reversible precipitation of calcium uranate and coffinite. Results between the different hydrogeochemical transport codes show differences in oxidation potentials, but similarities in mineral assemblages and aqueous transport patterns. Because model verification can be further complicated by differences in the approach for solving redox problems, a comparison of a fugacity approach to both the external approach (based on hypothetical electron activity) and effective internal approach (based on conservation of electrons) is performed. The comparison demonstrates that the oxygen fugacity approach produces different redox potentials and mineral assemblages than both the effective internal and external approaches.

  15. SCDAP/RELAP5 modeling of heat transfer and flow losses in lower head porous debris. Revision 1

    SciTech Connect (OSTI)

    Siefken, L.J.; Coryell, E.W.; Paik, S.; Kuo, H.

    1999-05-01

    Designs are described for implementing models for calculating the heat transfer and flow losses in porous debris in the lower head of a reactor vessel. The COUPLE model in SCDAP/RELAP5 represents both the porous and nonporous debris that results from core material slumping into the lower head. Currently, the COUPLE model has the capability to model convective and radiative heat transfer from the surfaces of nonporous debris in a detailed manner and to model only in a simplistic manner the heat transfer from porous debris. In order to advance beyond the simplistic modeling for porous debris, designs are developed for detailed calculations of heat transfer and flow losses in porous debris. Correlations are identified for convective heat transfer in porous debris for the following modes of heat transfer; (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, and (5) film boiling. Interphase heat transfer is modeled in an approximate ma nner. Designs are described for models to calculate the flow losses and interphase drag of fluid flowing through the interstices of the porous debris, and to apply these variables in the momentum equations in the RELAP5 part of the code. Since the models for heat transfer and flow losses in porous debris in the lower head are designed for general application, a design is also described for implementation of these models to the analysis of porous debris in the core region. A test matrix is proposed for assessing the capability of the implemented models to calculate the heat transfer and flow losses in porous debris. The implementation of the models described in this report is expected to improve the COUPLE code calculation of the temperature distribution in porous debris and in the lower head that supports the debris. The implementation of these models is also expected to improve the calculation of the temperature and flow distribution in porous debris in the core region.

  16. Field demonstration of rapid turnaround, multilevel groundwater screening

    SciTech Connect (OSTI)

    Tingle, A.R.; Baker, L.; Long, D.D.; Miracle, M.

    1994-09-01

    A combined technology approach to rapidly characterizing source area and downgradient groundwater associated with a past fuel spill has been field tested. The purpose of this investigation was to determine the presence and extent of fuel-related compounds or indications of their biodegradation in groundwater. The distance from the source area to be investigated was established by calculating the potential extent of a plume based only on groundwater flow velocities. To accomplish this objective, commercially available technologies were combined and used to rapidly assess the source area and downgradient groundwater associated with the fuel discharge. The source of contamination that was investigated overlies glacial sand and gravel outwash deposits. Historical data suggest that from 1955 to 1970 as many as 1 to 6 million pi of aviation gasoline (AVGAS) were god at the study area. Although the remedial investigation (RI) for this study area indicated fuel-related groundwater contamination at the source area, fuel-related contamination was not detected in downgradient monitoring wells. Rapid horizontal groundwater velocities and the 24-year time span from the last reported spill farther suggest that a plume of contaminated groundwater could extend several thousand feet downgradient. The lack of contamination downgradient from the source suggests two possibilities: (1) monitoring wells installed during the RI did not intersect the plume or (2) fuel-related compounds had naturally degraded.

  17. Effect of radon transport in groundwater upon gamma-ray borehole logs

    SciTech Connect (OSTI)

    Nelson, P.H.; Rachiele, R.; Smith, A.

    1980-09-01

    Granitic rock at an experimental waste storage site at Stripa, Sweden, is unusually high in natural radioelements (40 ppM uranium) with higher concentrations occurring locally in thin chloritic zones and fractures. Groundwater seeping through fractures into open boreholes is consequently highly anomalous in its radon content, with activity as high as one microcurie per liter. When total count gamma-ray logs are run in boreholes where groundwater inflow is appreciable, the result is quite unusual: the radon daughter activity in the water adds considerably to the contribution from the rock, and in fact often dominates the log response. The total gamma activity increases where radon-charged groundwater enters a borehole, and remains at a high level as the water flows along the hole in response to the hydraulic gradient. As a consequence, the gamma log serves as a flow profile, locating zones of water entry (or loss) by an increase (or decrease) in the total gamma activity. A simple model has been developed for flow through a thin crack emanating radon at a rate E showing that the radon concentration of water entering a hole is E/..lambda..h, where ..lambda.. is the radon decay rate and h the crack aperture, assuming that the flow rate and crack source area are such that an element of water resides within the source area for several radon half-lives or more. Concentration measurements can provide a measurement of the inflow rate. Data from the 127-mm holes in the time-scale drift behave in this fashion.

  18. Prediction of turbulent buoyant flow using an RNG {kappa}-{epsilon} model

    SciTech Connect (OSTI)

    Gan, G.

    1998-02-06

    Buoyant flows occur in various engineering practices such as heating, ventilation, and air-conditioning of buildings. This phenomenon is particularly important in rooms with displacement ventilation, where supply air velocities are generally very low (< 0.2 m/s) so that the predominant indoor airflow is largely due to thermal buoyancy created by internal heat sources such as occupants and equipment. This type of ventilation system has been shown to be an effective means to remove excess heat and achieve good indoor air quality. Here, numerical predictions were carried out for turbulent natural convection in two tall air cavities. The standard and RNG {kappa}-{epsilon} turbulence models were used for the predictions. The predicted results were compared with experimental data from the literature, and good agreement between prediction and measurement was obtained. Improved prediction was achieved using the RNG {kappa}-{epsilon} model in comparison with the standard {kappa}-{epsilon} model. The principal parameters for the improvement were investigated.

  19. On the modeling of a single-stage, entrained-flow gasifier using Aspen Custom Modeler (ACM)

    SciTech Connect (OSTI)

    Kasule, J.; Turton, R.; Bhattacharyya, D.; Zitney, S.

    2010-01-01

    Coal-fired gasifiers are the centerpiece of integrated gasification combined cycle (IGCC) power plants. The gasifier produces synthesis gas that is subsequently converted into electricity through combustion in a gas turbine. Several mathematical models have been developed to study the physical and chemical processes taking place inside the gasifier. Such models range from simple one-dimensional (1D) steady-state models to sophisticated dynamic 3D computational fluid dynamics (CFD) models that incorporate turbulence effects in the reactor. The practical operation of the gasifier is dynamic in nature but most 1D and some higher-dimensional models are often steady state. On the other hand, many higher order CFD-based models are dynamic in nature, but are too computationally expensive to be used directly in operability and controllability dynamic studies. They are also difficult to incorporate in the framework of process simulation software such as Aspen Plus Dynamics. Thus lower-dimensional dynamic models are still useful in these types of studies. In the current study, a 1D dynamic model for a single-stage, downward-firing, entrained-flow GE-type gasifier is developed using Aspen Custom Modeler{reg_sign} (ACM), which is a commercial equation-based simulator for creating, editing, and re-using models of process units. The gasifier model is based on mass, momentum, and energy balances for the solid and gas phases. The physical and chemical reactions considered in the model are drying, devolatilization/pyrolysis, gasification, combustion, and the homogeneous gas phase reactions. The dynamic gasifier model is being developed for use in a plant-wide dynamic model of an IGCC power plant. For dynamic simulation, the resulting highly nonlinear system of partial differential algebraic equations (PDAE) is solved in ACM using the well-known Method of Lines (MoL) approach. The MoL discretizes the space domain and leaves the time domain continuous, thereby converting the PDAE to

  20. Computational fluid dynamics modeling of two-phase flow in a BWR fuel assembly. Final CRADA Report.

    SciTech Connect (OSTI)

    Tentner, A.; Nuclear Engineering Division

    2009-10-13

    A direct numerical simulation capability for two-phase flows with heat transfer in complex geometries can considerably reduce the hardware development cycle, facilitate the optimization and reduce the costs of testing of various industrial facilities, such as nuclear power plants, steam generators, steam condensers, liquid cooling systems, heat exchangers, distillers, and boilers. Specifically, the phenomena occurring in a two-phase coolant flow in a BWR (Boiling Water Reactor) fuel assembly include coolant phase changes and multiple flow regimes which directly influence the coolant interaction with fuel assembly and, ultimately, the reactor performance. Traditionally, the best analysis tools for this purpose of two-phase flow phenomena inside the BWR fuel assembly have been the sub-channel codes. However, the resolution of these codes is too coarse for analyzing the detailed intra-assembly flow patterns, such as flow around a spacer element. Advanced CFD (Computational Fluid Dynamics) codes provide a potential for detailed 3D simulations of coolant flow inside a fuel assembly, including flow around a spacer element using more fundamental physical models of flow regimes and phase interactions than sub-channel codes. Such models can extend the code applicability to a wider range of situations, which is highly important for increasing the efficiency and to prevent accidents.

  1. Two-fluid Hydrodynamic Model for Fluid-Flow Simulation in Fluid-Solids Systems

    Energy Science and Technology Software Center (OSTI)

    1994-06-20

    FLUFIX is a two-dimensional , transient, Eulerian, and finite-difference program, based on a two-fluid hydrodynamic model, for fluid flow simulation in fluid-solids systems. The software is written in a modular form using the Implicit Multi-Field (IMF) numerical technique. Quantities computed are the spatial distribution of solids loading, gas and solids velocities, pressure, and temperatures. Predicted are bubble formation, bed frequencies, and solids recirculation. Applications include bubbling and circulating atmospheric and pressurized fluidized bed reactors, combustors,more » gasifiers, and FCC (Fluid Catalytic Cracker) reactors.« less

  2. One- and two-dimensional Stirling machine simulation using experimentally generated reversing flow turbuulence models

    SciTech Connect (OSTI)

    Goldberg, L.F.

    1990-08-01

    The activities described in this report do not constitute a continuum but rather a series of linked smaller investigations in the general area of one- and two-dimensional Stirling machine simulation. The initial impetus for these investigations was the development and construction of the Mechanical Engineering Test Rig (METR) under a grant awarded by NASA to Dr. Terry Simon at the Department of Mechanical Engineering, University of Minnesota. The purpose of the METR is to provide experimental data on oscillating turbulent flows in Stirling machine working fluid flow path components (heater, cooler, regenerator, etc.) with particular emphasis on laminar/turbulent flow transitions. Hence, the initial goals for the grant awarded by NASA were, broadly, to provide computer simulation backup for the design of the METR and to analyze the results produced. This was envisaged in two phases: First, to apply an existing one-dimensional Stirling machine simulation code to the METR and second, to adapt a two-dimensional fluid mechanics code which had been developed for simulating high Rayleigh number buoyant cavity flows to the METR. The key aspect of this latter component was the development of an appropriate turbulence model suitable for generalized application to Stirling simulation. A final-step was then to apply the two-dimensional code to an existing Stirling machine for which adequate experimental data exist. The work described herein was carried out over a period of three years on a part-time basis. Forty percent of the first year`s funding was provided as a match to the NASA funds by the Underground Space Center, University of Minnesota, which also made its computing facilities available to the project at no charge.

  3. Modeling the Air Flow in the 3410 Building Filtered Exhaust Stack System

    SciTech Connect (OSTI)

    Recknagle, Kurtis P.; Barnett, J. M.; Suffield, Sarah R.

    2013-01-23

    Additional ventilation capacity has been designed for the 3410 Building filtered exhaust stack system. The updated system will increase the number of fans from two to three and will include ductwork to incorporate the new fan into the existing stack. Stack operations will involve running various two-fan combinations at any given time. The air monitoring system of the existing two-fan stack was previously found to be in compliance with the ANSI/HPS N13.1-1999 standard, however it is not known if the modified (three-fan) system will comply. Subsequently, a full-scale three-dimensional (3-D) computational fluid dynamics (CFD) model of the modified stack system has been created to examine the sampling location for compliance with the standard. The CFD modeling results show good agreement with testing data collected from the existing 3410 Building stack and suggest that velocity uniformity and flow angles will remain well within acceptance criteria when the third fan and associated ductwork is installed. This includes two-fan flow rates up to 31,840 cfm for any of the two-fan combinations. For simulation cases in which tracer gas and particles are introduced in the main duct, the model predicts that both particle and tracer gas coefficients of variance (COVs) may be larger than the acceptable 20 percent criterion of the ANSI/HPS N13.1-1999 standard for each of the two-fan, 31,840 cfm combinations. Simulations in which the tracers are introduced near the fans result in improved, though marginally acceptable, COV values for the tracers. Due to the remaining uncertainty that the stack will qualify with the addition of the third fan and high flow rates, a stationary air blender from Blender Products, Inc. is considered for inclusion in the stack system. A model of the air blender has been developed and incorporated into the CFD model. Simulation results from the CFD model that includes the air blender show striking improvements in tracer gas mixing and tracer particle

  4. Consistent multi-internal-temperature models for vibrational and electronic nonequilibrium in hypersonic nitrogen plasma flows

    SciTech Connect (OSTI)

    Guy, Aurlien Bourdon, Anne Perrin, Marie-Yvonne

    2015-04-15

    In this work, a state-to-state vibrational and electronic collisional model is developed to investigate nonequilibrium phenomena behind a shock wave in an ionized nitrogen flow. In the ionization dynamics behind the shock wave, the electron energy budget is of key importance and it is found that the main depletion term corresponds to the electronic excitation of N atoms, and conversely the major creation terms are the electron-vibration term at the beginning, then replaced by the electron ions elastic exchange term. Based on these results, a macroscopic multi-internal-temperature model for the vibration of N{sub 2} and the electronic levels of N atoms is derived with several groups of vibrational levels of N{sub 2} and electronic levels of N with their own internal temperatures to model the shape of the vibrational distribution of N{sub 2} and of the electronic excitation of N, respectively. In this model, energy and chemistry source terms are calculated self-consistently from the rate coefficients of the state-to-state database. For the shock wave condition studied, a good agreement is observed on the ionization dynamics as well as on the atomic bound-bound radiation between the state-to-state model and the macroscopic multi-internal temperature model with only one group of vibrational levels of N{sub 2} and two groups of electronic levels of N.

  5. Improvement of Stent Retriever Design and Efficacy of Mechanical Thrombectomy in a Flow Model

    SciTech Connect (OSTI)

    Wenger, Katharina; Nagl, Frank; Wagner, Marlies Berkefeld, Joachim

    2013-02-15

    In vitro experiments were performed to evaluate the efficacy of mechanical intracranial thrombectomy comparing the newly developed Aperio stent retriever and standard devices for stroke treatment. The Aperio (A), with an increased working length of 4 cm and a special cell design for capturing and withholding clots, was compared to three benchmark devices: the Solitaire retrievable stent (B), the Merci X6 (C), and the Merci L5 retriever (D). In a vascular glass model with pulsatile flow, reminiscent of the M1 segment of the middle cerebral artery, we repeatedly induced occlusion by generating thrombi via a modified Chandler loop system. The numbers of recanalization attempts, peripheral embolizations, and recanalizations at the site of occlusion were recorded during 10 retrieval experiments with each device. Eleven devices were able to remove the blood clots from the occluded branch. In 34 of 40 experiments, restoration of flow was obtained in 1-3 attempts. The main differences between the study devices were observed in terms of clot withholding and fragmentation during retrieval. Although there was only one fragmentation recorded for device A, disengagement of the whole clot or peripheral embolization of fragments occurred more frequently (5-7 times) with devices B, C, and D. In a vascular model, the design of device A was best at capturing and withholding thrombi during retrieval. Further study will be necessary to see whether this holds true in clinical applications.

  6. Recent numerical and algorithmic advances within the volume tracking framework for modeling interfacial flows

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    François, Marianne M.

    2015-05-28

    A review of recent advances made in numerical methods and algorithms within the volume tracking framework is presented. The volume tracking method, also known as the volume-of-fluid method has become an established numerical approach to model and simulate interfacial flows. Its advantage is its strict mass conservation. However, because the interface is not explicitly tracked but captured via the material volume fraction on a fixed mesh, accurate estimation of the interface position, its geometric properties and modeling of interfacial physics in the volume tracking framework remain difficult. Several improvements have been made over the last decade to address these challenges.more » In this study, the multimaterial interface reconstruction method via power diagram, curvature estimation via heights and mean values and the balanced-force algorithm for surface tension are highlighted.« less

  7. Explanation of Significant Differences Between Models used to Assess Groundwater Impacts for the Disposal of Greater-Than-Class C Low-Level Radioactive Waste and Greater-Than-Class C-Like Waste Environmental Impact Statement (DOE/EIS-0375-D) and the

    SciTech Connect (OSTI)

    Annette Schafer; Arthur S. Rood; A. Jeffrey Sondrup

    2011-08-01

    Models have been used to assess the groundwater impacts to support the Draft Environmental Impact Statement for the Disposal of Greater-Than-Class C (GTCC) Low-Level Radioactive Waste and GTCC-Like Waste (DOE-EIS 2011) for a facility sited at the Idaho National Laboratory and the Environmental Assessment for the INL Remote-Handled Low-Level Waste Disposal Project (INL 2011). Groundwater impacts are primarily a function of (1) location determining the geologic and hydrologic setting, (2) disposal facility configuration, and (3) radionuclide source, including waste form and release from the waste form. In reviewing the assumptions made between the model parameters for the two different groundwater impacts assessments, significant differences were identified. This report presents the two sets of model assumptions and discusses their origins and implications for resulting dose predictions. Given more similar model parameters, predicted doses would be commensurate.

  8. A flowing plasma model to describe drift waves in a cylindrical helicon discharge

    SciTech Connect (OSTI)

    Chang, L.; Hole, M. J.; Corr, C. S.

    2011-04-15

    A two-fluid model developed originally to describe wave oscillations in the vacuum arc centrifuge, a cylindrical, rapidly rotating, low temperature, and confined plasma column, is applied to interpret plasma oscillations in a RF generated linear magnetized plasma [WOMBAT (waves on magnetized beams and turbulence)], with similar density and field strength. Compared to typical centrifuge plasmas, WOMBAT plasmas have slower normalized rotation frequency, lower temperature, and lower axial velocity. Despite these differences, the two-fluid model provides a consistent description of the WOMBAT plasma configuration and yields qualitative agreement between measured and predicted wave oscillation frequencies with axial field strength. In addition, the radial profile of the density perturbation predicted by this model is consistent with the data. Parameter scans show that the dispersion curve is sensitive to the axial field strength and the electron temperature, and the dependence of oscillation frequency with electron temperature matches the experiment. These results consolidate earlier claims that the density and floating potential oscillations are a resistive drift mode, driven by the density gradient. To our knowledge, this is the first detailed physics model of flowing plasmas in the diffusion region away from the RF source. Possible extensions to the model, including temperature nonuniformity and magnetic field oscillations, are also discussed.

  9. Response of a laminar premixed flame to flow oscillations: A kinematic model and thermoacoustic instability results

    SciTech Connect (OSTI)

    Fleifil, M.; Annaswamy, A.M.; Ghoneim, A.F.; Ghoneim, Z.A.

    1996-09-01

    Combustion instability is a resonance phenomenon that arises due to the coupling between the system acoustics and the unsteady heat release. The constructive feedback between the two processes, which is known to occur as a certain phase relationship between the pressure and the unsteady heat release rate is satisfied, depends on many parameters among which is the acoustic mode, the flame holder characteristics, and the dominant burning pattern. In this paper, the authors construct an analytical model to describe the dynamic response of a laminar premixed flame stabilized on the rim of a tube to velocity oscillation. They consider uniform and nonuniform velocity perturbations superimposed on a pipe flow velocity profile. The model results show that the magnitude of heat release perturbation and its phase with respect to the dynamic perturbation dependent primarily on the flame Strohal number, representing the ratio of the dominant frequency times the tube radius to the laminar burning velocity. In terms of this number, high-frequency perturbations pass through the flame while low frequencies lead to a strong response. The phase with respect to the velocity perturbation behaves in the opposite way. Results of this model are shown to agree with experimental observations and to be useful in determining how the combustion excited model is selected among all the acoustic unstable modes. The model is then used to obtain a time-domain differential equation describing the relationship between the velocity perturbation and the heat release response over the entire frequency range.

  10. Bedrock refractive-flow cells: A passive treatment analog to funnel-and-gate

    SciTech Connect (OSTI)

    Dick, V.; Edwards, D.

    1997-12-31

    Funnel-and-gate technology provides a mechanism to passively treat groundwater contaminant plumes, but depends on placement of a sufficient barrier ({open_quotes}funnel{close_quotes}) in the plume flow path to channel the plume to a pass-through treatment zone ({open_quotes}gate{close_quotes}). Conventional barrier technologies limit funnel-and-gate deployment to unconsolidated overburden applications. A method has been developed which allows similar passive treatment to be applied to bedrock plumes. Rather than use barriers as the funnel, the method uses engineered bedrock zones, installed via precision blasting or other means, to refract groundwater flow along a preferred path to treatment (gate). The method requires orienting the refractive cell based on the Tangent Law and extending refractive cell limbs down gradient of the gate to disperse head and control flow. A typical Refractive-Flow cell may be{open_quotes}Y{close_quotes}shaped, with each limb 3-10 ft [1-3 m] wide and several tens to a few hundred feet [10 - 100 m] in length. Treatment takes place at the center of the X. MODFLOW modeling has been used to successfully simulate desired flow. Engineered blasting has been used at full scale application to create bedrock rubble zones for active collection/flow control for several years. The method provides a previously unavailable method to passively treat contaminated groundwater in bedrock at low cost.

  11. Groundwater monitoring system

    DOE Patents [OSTI]

    Ames, Kenneth R.; Doesburg, James M.; Eschbach, Eugene A.; Kelley, Roy C.; Myers, David A.

    1987-01-01

    A groundwater monitoring system includes a bore, a well casing within and spaced from the bore, and a pump within the casing. A water impermeable seal between the bore and the well casing prevents surface contamination from entering the pump. Above the ground surface is a removable operating means which is connected to the pump piston by a flexible cord. A protective casing extends above ground and has a removable cover. After a groundwater sample has been taken, the cord is disconnected from the operating means. The operating means is removed for taking away, the cord is placed within the protective casing, and the cover closed and locked. The system is thus protected from contamination, as well as from damage by accident or vandalism.

  12. Validation and Calibration of Nuclear Thermal Hydraulics Multiscale Multiphysics Models - Subcooled Flow Boiling Study

    SciTech Connect (OSTI)

    Anh Bui; Nam Dinh; Brian Williams

    2013-09-01

    In addition to validation data plan, development of advanced techniques for calibration and validation of complex multiscale, multiphysics nuclear reactor simulation codes are a main objective of the CASL VUQ plan. Advanced modeling of LWR systems normally involves a range of physico-chemical models describing multiple interacting phenomena, such as thermal hydraulics, reactor physics, coolant chemistry, etc., which occur over a wide range of spatial and temporal scales. To a large extent, the accuracy of (and uncertainty in) overall model predictions is determined by the correctness of various sub-models, which are not conservation-laws based, but empirically derived from measurement data. Such sub-models normally require extensive calibration before the models can be applied to analysis of real reactor problems. This work demonstrates a case study of calibration of a common model of subcooled flow boiling, which is an important multiscale, multiphysics phenomenon in LWR thermal hydraulics. The calibration process is based on a new strategy of model-data integration, in which, all sub-models are simultaneously analyzed and calibrated using multiple sets of data of different types. Specifically, both data on large-scale distributions of void fraction and fluid temperature and data on small-scale physics of wall evaporation were simultaneously used in this works calibration. In a departure from traditional (or common-sense) practice of tuning/calibrating complex models, a modern calibration technique based on statistical modeling and Bayesian inference was employed, which allowed simultaneous calibration of multiple sub-models (and related parameters) using different datasets. Quality of data (relevancy, scalability, and uncertainty) could be taken into consideration in the calibration process. This work presents a step forward in the development and realization of the CIPS Validation Data Plan at the Consortium for Advanced Simulation of LWRs to enable

  13. Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model

    SciTech Connect (OSTI)

    Sharma, Chandan; Raustad, Richard

    2013-06-01

    Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

  14. Re-evaluation of a subsurface injection experiment for testing flow and transport models

    SciTech Connect (OSTI)

    Fayer, M.J.; Lewis, R.E.; Engelman, R.E.; Pearson, A.L.; Murray, C.J.; Smoot, J.L. Lu, A.H.; Randall, P.R.; Wegener, W.H.

    1995-12-01

    The current preferred method for disposal of low-level radioactive waste (LLW) at the Hanford Site is to vitrify the wastes so they can be stored in a near-surface, shallow-land burial facility (Shord 1995). Pacific Northwest Laboratory (PNL) managed the PNL Vitrification Technology Development (PVTD) Project to assist Westinghouse Hanford Company (WHC) in designing and assessing the performance of a disposal facility for the vitrified LLW. Vadose zone flow and transport models are recognized as necessary tools for baseline risk assessments of stored waste forms. The objective of the Controlled Field Testing task of the PVTD Project is to perform and analyze field experiments to demonstrate the appropriateness of conceptual models for the performance assessment. The most convincing way to demonstrate appropriateness is to show that the model can reproduce the movement of water and contaminants in the field. Before expensive new experiments are initiated, an injection experiment conducted at the Hanford Site in 1980 (designated the ``Sisson and the Lu experiment``) should be completely analyzed and understood. Briefly, in that test, a solution containing multiple tracers was injected at a single point into the subsurface sediments. The resulting spread of the water and tracers was monitored in wells surrounding the injection point. Given the advances in knowledge, computational capabilities, and models over the last 15 years, it is important to re-analyze the data before proceeding to other experiments and history-matching exercises.

  15. A Unified Multi-Scale Model for Pore-Scale Flow Simulations in Soils

    SciTech Connect (OSTI)

    Yang, Xiaofan; Liu, Chongxuan; Shang, Jianying; Fang, Yilin; Bailey, Vanessa L.

    2014-01-30

    Pore-scale simulations have received increasing interest in subsurface sciences to provide mechanistic insights into the macroscopic phenomena of water flow and reactive transport processes. The application of the pore scale simulations to soils and sediments is, however, challenged because of the characterization limitation that often only allows partial resolution of pore structure and geometry. A significant proportion of the pore space in soils and sediments is below the spatial resolution, forming a mixed media of pore and porous domains. Here we reported a unified multi-scale model (UMSM) that can be used to simulate water flow and transport in mixed media of pore and porous domains under both saturated and unsaturated conditions. The approach modifies the classic Navier-Stokes equation by adding a Darcy term to describe fluid momentum and uses a generalized mass balance equation for saturated and unsaturated conditions. By properly defining physical parameters, the UMSM can be applied in both pore and porous domains. This paper describes the set of equations for the UMSM, a series of validation cases under saturated or unsaturated conditions, and a real soil case for the application of the approach.

  16. Modeling of Immiscible, Two-Phase Flows in a Natural Rock Fracture

    SciTech Connect (OSTI)

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H

    2009-01-01

    One potential method of geologically sequestering carbon dioxide (CO2) is to inject the gas into brine-filled, subsurface formations. Within these low-permeability rocks, fractures exist that can act as natural fluid conduits. Understanding how a less viscous fluid moves when injected into an initially saturated rock fracture is important for the prediction of CO2 transport within fractured rocks. Our study examined experimentally and numerically the motion of immiscible fluids as they were transported through models of a fracture in Berea sandstone. The natural fracture geometry was initially scanned using micro-computerized tomography (CT) at a fine volume-pixel (voxel) resolution by Karpyn et al. [1]. This CT scanned fracture was converted into a numerical mesh for two-phase flow calculations using the finite-volume solver FLUENT® and the volume-of-fluid method. Additionally, a translucent experimental model was constructed using stereolithography. The numerical model was shown to agree well with experiments for the case of a constant rate injection of air into the initially water-saturated fracture. The invading air moved intermittently, quickly invading large-aperture regions of the fracture. Relative permeability curves were developed to describe the fluid motion. These permeability curves can be used in reservoir-scale discrete fracture models for predictions of fluid motion within fractured geological formations. The numerical model was then changed to better mimic the subsurface conditions at which CO2 will move into brine saturated fractures. The different fluid properties of the modeled subsurface fluids were shown to increase the amount of volume the less-viscous invading gas would occupy while traversing the fracture.

  17. Microsoft Word - Groundwater Discharge Permit

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    State Renews Groundwater Discharge Permit for WIPP CARLSBAD, N.M., September 11, 2008 - The New Mexico Environment Department (NMED) has renewed the U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) groundwater discharge permit until 2013. The permit regulates the discharge of water from WIPP facilities and operations to lined ponds, which protect groundwater resources. The permit allows WIPP to discharge domestic wastewater, non-hazardous wastewater and storm water into 13

  18. A model problem of deceleration of a body in a resisting medium with a jet flow around the body

    SciTech Connect (OSTI)

    Eroshin, V.A.; Samsonov, V.A.; Shamolin, M.V.

    1995-11-01

    A mathematical model is constructed describing the deceleration of a solid body moving in a medium with a jet flow around the body. The regime of translational deceleration is shown to be normally unstable. This has made it possible to develop a relatively simple technique for determining model parameters experimentally. An example of the application of this technique to a cylindrical body is presented.

  19. Modeling hot gas flow in the low-luminosity active galactic nucleus of NGC 3115

    SciTech Connect (OSTI)

    Shcherbakov, Roman V.; Reynolds, Christopher S.; Wong, Ka-Wah; Irwin, Jimmy A.

    2014-02-20

    Based on the dynamical black hole (BH) mass estimates, NGC 3115 hosts the closest billion solar mass BH. Deep studies of the center revealed a very underluminous active galactic nucleus (AGN) immersed in an old massive nuclear star cluster. Recent 1 Ms Chandra X-ray visionary project observations of the NGC 3115 nucleus resolved hot tenuous gas, which fuels the AGN. In this paper we connect the processes in the nuclear star cluster with the feeding of the supermassive BH. We model the hot gas flow sustained by the injection of matter and energy from the stars and supernova explosions. We incorporate electron heat conduction as the small-scale feedback mechanism, the gravitational pull of the stellar mass, cooling, and Coulomb collisions. Fitting simulated X-ray emission to the spatially and spectrally resolved observed data, we find the best-fitting solutions with ?{sup 2}/dof = 1.00 for dof = 236 both with and without conduction. The radial modeling favors a low BH mass <1.3 10{sup 9} M {sub ?}. The best-fitting supernova rate and the best-fitting mass injection rate are consistent with their expected values. The stagnation point is at r {sub st} ? 1'', so that most of the gas, including the gas at a Bondi radius r{sub B} = 2''-4'', outflows from the region. We put an upper limit on the accretion rate at 2 10{sup 3} M {sub ?} yr{sup 1}. We find a shallow density profile n?r {sup ?} with ? ? 1 over a large dynamic range. This density profile is determined in the feeding region 0.''5-10'' as an interplay of four processes and effects: (1) the radius-dependent mass injection, (2) the effect of the galactic gravitational potential, (3) the accretion flow onset at r ? 1'', and (4) the outflow at r ? 1''. The gas temperature is close to the virial temperature T{sub v} at any radius.

  20. River stage influences on uranium transport in a hydrologically dynamic groundwater-surface water transition zone

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zachara, John M.; Chen, Xingyuan; Murray, Chris; Hammond, Glenn

    2016-03-04

    A well-field within a uranium (U) plume in the groundwater-surface water transition zone was monitored for a 3 year period for water table elevation and dissolved solutes. The plume discharges to the Columbia River, which displays a dramatic spring stage surge resulting from snowmelt. Groundwater exhibits a low hydrologic gradient and chemical differences with river water. River water intrudes the site in spring. Specific aims were to assess the impacts of river intrusion on dissolved uranium (Uaq), specific conductance (SpC), and other solutes, and to discriminate between transport, geochemical, and source term heterogeneity effects. As a result of water tablemore » elevation fluctuations, river water intrusion, and changes in groundwater flow directions, time series trends for Uaq and SpC were found to be complex and displayed large temporal and well-to-well variability. The wells were clustered into subsets exhibiting common behaviors resulting from the intrusion dynamics of river water and the location of source terms. Hot-spots in Uaq varied in location with increasing water table elevation through the combined effects of advection and source term location. Heuristic reactive transport modeling with PFLOTRAN demonstrated that mobilized Uaq was transported between wells and source terms in complex trajectories, and was diluted as river water entered and exited the groundwater system. Moreover, while Uaq time-series concentration trends varied significantly from year-to-year as a result of climate-caused differences in the spring hydrograph, common and partly predictable response patterns were observed that were driven by water table elevation, and the extent and duration of river water intrusion.« less

  1. River stage influences on uranium transport in a hydrologically dynamic groundwater-surface water transition zone

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zachara, John M.; Chen, Xingyuan; Murray, Chris; Hammond, Glenn

    2016-03-04

    In this study, a well-field within a uranium (U) plume in the groundwater-surface water transition zone was monitored for a 3 year period for water table elevation and dissolved solutes. The plume discharges to the Columbia River, which displays a dramatic spring stage surge resulting from snowmelt. Groundwater exhibits a low hydrologic gradient and chemical differences with river water. River water intrudes the site in spring. Specific aims were to assess the impacts of river intrusion on dissolved uranium (Uaq), specific conductance (SpC), and other solutes, and to discriminate between transport, geochemical, and source term heterogeneity effects. Time series trendsmore » for Uaq and SpC were complex and displayed large temporal and well-to-well variability as a result of water table elevation fluctuations, river water intrusion, and changes in groundwater flow directions. The wells were clustered into subsets exhibiting common behaviors resulting from the intrusion dynamics of river water and the location of source terms. Hot-spots in Uaq varied in location with increasing water table elevation through the combined effects of advection and source term location. Heuristic reactive transport modeling with PFLOTRAN demonstrated that mobilized Uaq was transported between wells and source terms in complex trajectories, and was diluted as river water entered and exited the groundwater system. While Uaq time-series concentration trends varied significantly from year-to-year as a result of climate-caused differences in the spring hydrograph, common and partly predictable response patterns were observed that were driven by water table elevation, and the extent and duration of river water intrusion.« less

  2. The role of subsurface flows in solar surface convection: modeling the spectrum of supergranular and larger scale flows

    SciTech Connect (OSTI)

    Lord, J. W.; Rast, M. P.; Cameron, R. H.; Rempel, M.; Roudier, T.

    2014-09-20

    We model the solar horizontal velocity power spectrum at scales larger than granulation using a two-component approximation to the mass continuity equation. The model takes four times the density scale height as the integral (driving) scale of the vertical motions at each depth. Scales larger than this decay with height from the deeper layers. Those smaller are assumed to follow a Kolmogorov turbulent cascade, with the total power in the vertical convective motions matching that required to transport the solar luminosity in a mixing length formulation. These model components are validated using large-scale radiative hydrodynamic simulations. We reach two primary conclusions. (1) The model predicts significantly more power at low wavenumbers than is observed in the solar photospheric horizontal velocity spectrum. (2) Ionization plays a minor role in shaping the observed solar velocity spectrum by reducing convective amplitudes in the regions of partial helium ionization. The excess low wavenumber power is also seen in the fully nonlinear three-dimensional radiative hydrodynamic simulations employing a realistic equation of state. This adds to other recent evidence suggesting that the amplitudes of large-scale convective motions in the Sun are significantly lower than expected. Employing the same feature tracking algorithm used with observational data on the simulation output, we show that the observed low wavenumber power can be reproduced in hydrodynamic models if the amplitudes of large-scale modes in the deep layers are artificially reduced. Since the large-scale modes have reduced amplitudes, modes on the scale of supergranulation and smaller remain important to convective heat flux even in the deep layers, suggesting that small-scale convective correlations are maintained through the bulk of the solar convection zone.

  3. PROBABILISTIC SIMULATION OF SUBSURFACE FLUID FLOW: A STUDY USING A NUMERICAL SCHEME

    SciTech Connect (OSTI)

    Buscheck, Timothy Eric

    1980-03-01

    There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and two-dimensional steady-stte flow through heterogeneous media. The results are compared with those available in the literature.

  4. Simulation of water flow in terrestrial systems

    Energy Science and Technology Software Center (OSTI)

    2008-12-18

    ParFlow is a parallel, variabley saturated groundwater flow code that is especially suitable for large scale problem. ParFlow simulates the three-dimensional saturated and variably saturated subsurface flow in heterogeneous porous media in three spatial dimensions. ParFlow's developemt and appkication has been on-ging for more than 10 uear. ParFlow has recently been extended to coupled surface-subsurface flow to enabel the simulation of hillslope runoff and channel routing in a truly integrated fashion. ParFlow simulates the three-dimensionalmore » varably saturated subsurface flow in strongly heterogeneous porous media in three spatial dimension.« less

  5. In-situ method to remove iron and other metals from Solution in Groundwater down Gradient from Permeable Reactive Barrier

    SciTech Connect (OSTI)

    Carpenter, Clay E.; Morrison, Stanley J.

    1999-09-22

    This invention is directed to a process for treating the flow of anaerobic groundwater through an aquifer with a primary treatment media, preferably iron, and then passing the treated groundwater through a second porous media though which an oxygenated gas is passed in order to oxygenate the dissolved primary treatment material and convert it into an insoluble material thereby removing the dissolved primary treatment material from the groundwater.

  6. In-situ method to remove iron and other metals from solution in groundwater down gradient from permeable reactive barrier

    SciTech Connect (OSTI)

    Carpenter, Clay E.; Morrison, Stanley J.

    2001-07-03

    This invention is directed to a process for treating the flow of anaerobic groundwater through an aquifer with a primary treatment media, preferably iron, and then passing the treated groundwater through a second porous media though which an oxygenated gas is passed in order to oxygenate the dissolved primary treatment material and convert it into an insoluble material thereby removing the dissolved primary treatment material from the groundwater.

  7. TWDB Groundwater Conservation Districts website | Open Energy...

    Open Energy Info (EERE)

    TWDB Groundwater Conservation Districts website Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- OtherOther: TWDB Groundwater Conservation...

  8. Groundwater Periodic Monitoring Reports | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Groundwater Periodic Monitoring Reports Groundwater Periodic Monitoring Reports Topic: David Rhodes DOE, Provided Information on the Watersheds at LANL and the Monitoring Schedule ...

  9. California Groundwater Management Plans | Open Energy Information

    Open Energy Info (EERE)

    Groundwater Management Plans Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- OtherOther: California Groundwater Management PlansLegal Published...

  10. Anatomy of a Groundwater Uranium Plume

    Office of Energy Efficiency and Renewable Energy (EERE)

    Groundwater containing legacy contaminants (pollutants that remain after their sources have been controlled) moves through aquifers in response to the hydraulic gradient. As the groundwater moves,...

  11. 300 Area Process Trenches Groundwater Monitoring Plan

    SciTech Connect (OSTI)

    Lindberg, Jonathan W.; Chou, Charissa J.

    2001-08-13

    This document is a proposed groundwater monitoring plan for the 300 Area process trenches to comply with RCRA final status, corrective action groundwater monitoring.

  12. Modeling the onset of flow instability for subcooled boiling in downflow

    SciTech Connect (OSTI)

    Qureshi, Z. ); Barry, J.J.; Crowley, C.J. )

    1990-01-01

    A postulated loss-of-coolant accident (LOCA) scenario for the Savannah River Plant (SRP) production reactors involves a double-ended break of a reactor primary coolant pipe. The flow of coolant (D{sub 2}O) in the reactor may decrease in such an event. As the flow into the reactor decreases, boiling may occur, followed by dryout and failure of the fuel due to overheating. A typical SRP fuel assembly consists of multiple concentric tubes containing the fuel and target materials. Coolant passes through the annular passages in the assembly in downflow. Under normal operating conditions, the flow rate is maintained high enough to suppress or minimize subcooled boiling, i.e. the flow remains essentially single phase throughout. At high coolant flow rates, the flow is single phase or partially developed subcooled boiling, and the pressure drop decreases with decreasing flow rate. Here friction dominates the pressure gradient, and the flow is stable. Below a certain flow rate, however, pressure drop may increase with decreasing flow rate. This occurs when significant voids are produced by boiling, resulting in a large acceleration component to the pressure drop. The negative slope of the curve leads to an instability because the pressure drop cannot adjust to compensate -- the flow is driven to a lower value. Overheating of the channel may result. 15 refs., 14 figs.

  13. Understanding composite explosive energetics: 3, Reactive flow modeling of aluminum reaction kinetics in PETN and TNT

    SciTech Connect (OSTI)

    Tao, W.C.; Tarver, C.M.; Ornellas, D.L.

    1991-12-06

    Using Fabry-Perot interferometry techniques, we have determined that early time rate of energy release from detonating PETN and TNT explosives filled with 5 and 10 wt % of either 5 {mu}m of 18 {mu}m spherical aluminum (Al) particles. From the measured particle velocity data, we are able to infer the reaction rate of aluminum with the detonation products, and calculate the extent of reaction 1--3 {mu}s after the detonation. We observed that a substantional portion of the aluminum metal in all of the PETN and TNE formulations reacted within the timeframe of the one-dimensional experiment. In the PETN formulation filed with 5 wt % of 5 {mu}m aluminum, all of the metal reacted within 1.5 {mu}s, resulting in an increase of 22% in energy compared to pure PETN. A reactive-flow hydrodynamic model based on the Zeldovich-von Neumann-Doring (ZND) description of the reaction zone and subsequent reaction produce expansion (Taylor wave) is used to interpret the reaction rate of the aluminum particles with detonation product gases. The diffusion-controlled reaction mechanism for aluminum and the global kinetic parameters used in the model have been found to be consistent for all the PETN and TNT formulations.

  14. Sub-grid drag models for horizontal cylinder arrays immersed in gas-particle multiphase flows

    SciTech Connect (OSTI)

    Sarkar, Avik; Sun, Xin; Sundaresan, Sankaran

    2013-09-08

    Immersed cylindrical tube arrays often are used as heat exchangers in gas-particle fluidized beds. In multiphase computational fluid dynamics (CFD) simulations of large fluidized beds, explicit resolution of small cylinders is computationally infeasible. Instead, the cylinder array may be viewed as an effective porous medium in coarse-grid simulations. The cylinders' influence on the suspension as a whole, manifested as an effective drag force, and on the relative motion between gas and particles, manifested as a correction to the gas-particle drag, must be modeled via suitable sub-grid constitutive relationships. In this work, highly resolved unit-cell simulations of flow around an array of horizontal cylinders, arranged in a staggered configuration, are filtered to construct sub-grid, or `filtered', drag models, which can be implemented in coarse-grid simulations. The force on the suspension exerted by the cylinders is comprised of, as expected, a buoyancy contribution, and a kinetic component analogous to fluid drag on a single cylinder. Furthermore, the introduction of tubes also is found to enhance segregation at the scale of the cylinder size, which, in turn, leads to a reduction in the filtered gas-particle drag.

  15. Modelling on dynamics properties of a stationary argon cascaded arc plasma flows

    SciTech Connect (OSTI)

    Wei, G. D.; Qi, X.; Yang, L.

    2014-03-15

    The gas dynamics properties of a stationary arc plasma flows are studied through the numerical simulations. A two dimensional axis-symmetric turbulent magneto-hydrodynamic plasma model is developed with the commercial code ANSYS FLUENT. The reliable ?-? model is used to account for turbulence. In this paper, the plasma is assumed to be a fluid following NavierStokes equations, respecting local thermodynamic equilibrium, and described by only one temperature. Distributions of the pressure, velocity, temperature, density, and electric potential inside of thus cascaded arc are obtained for an arc current density of 10{sup 6}?A/m{sup 2}. The pressure inside the arc varies from 10{sup 5}?Pa to 100?Pa. The temperature at the arc axis can reach as high as 13?600?K. The electric potential drops uniformly along the axis with a magnitude of 160?V. In addition, distributions of the sonic velocity and Mach number are shown to describe supersonic behavior of thus cascaded arc, which have a good agreement with the analytical formula.

  16. Components for Atomistic-to-Continuum Multiscale Modeling of Flow in Micro- and Nanofluidic Systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adalsteinsson, Helgi; Debusschere, Bert J.; Long, Kevin R.; Najm, Habib N.

    2008-01-01

    Micro- and nanofluidics pose a series of significant challenges for science-based modeling. Key among those are the wide separation of length- and timescales between interface phenomena and bulk flow and the spatially heterogeneous solution properties near solid-liquid interfaces. It is not uncommon for characteristic scales in these systems to span nine orders of magnitude from the atomic motions in particle dynamics up to evolution of mass transport at the macroscale level, making explicit particle models intractable for all but the simplest systems. Recently, atomistic-to-continuum (A2C) multiscale simulations have gained a lot of interest as an approach to rigorously handle particle-levelmore » dynamics while also tracking evolution of large-scale macroscale behavior. While these methods are clearly not applicable to all classes of simulations, they are finding traction in systems in which tight-binding, and physically important, dynamics at system interfaces have complex effects on the slower-evolving large-scale evolution of the surrounding medium. These conditions allow decomposition of the simulation into discrete domains, either spatially or temporally. In this paper, we describe how features of domain decomposed simulation systems can be harnessed to yield flexible and efficient software for multiscale simulations of electric field-driven micro- and nanofluidics.« less

  17. Bioremediation of contaminated groundwater: A turnkey approach

    SciTech Connect (OSTI)

    Shivjiani, D.M.; Rudy, R.J.; Burns, B.; Heuler, G.

    1994-12-31

    The Silvex Corporation Site is a Florida state funded remedial action site in St. Augustine, Florida, that, prior to 1980, was a silver smelting facility that accepted waste materials from the Naval Air Station-Jacksonville. Fuels, reportedly consisting of waste paint, cold carbon removers, and solvent degreasers that were stored in a 25,000-gallon tank, spilled onto the property. The assessment concluded that the surficial aquifer in the spill area and the area hydrologically down-gradient of the spill were contaminated by elevated levels of ketones (acetone, methyl-ethyl ketone, and methyl-isobutyl ketone), phenols, and toluene. Subsequently, a risk assessment/feasibility study and groundwater bench-scale and pilot-scale studies were performed to determine the technical feasibility/cost-effectiveness of the recommended alternative, submerged fixed-film bioremediation. The on-site pilot study, which was conducted at three flow rates (0.5, 1, and 2 gallons per minute [gpm]), demonstrated a greater than 99% contaminant removal efficiency from the three-stage bioreactor. Due to the impact of site contamination on a nearby creek that flows into the St. Johns River, an interim remedial deign was developed and implemented to reduce the potential for migration of contaminated groundwater into the creek.

  18. Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core

    SciTech Connect (OSTI)

    Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M.

    2012-07-01

    The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

  19. Effect of Compressibility on Hyperbolicity and Choke Flow Criterion of the Two-phase Two-fluid Model

    SciTech Connect (OSTI)

    Suneet Singh; Vincent A. Mousseau

    2008-09-01

    The standard two-phase two-fluid model lacks hyperbolicity which results in oscillations in the numerical solutions. For the incompressible two-phase flows an exact correction term can be derived which when added to the momentum equations makes the model hyperbolic. No such straightforward approach exists for the similar compressible flows. In the current work, the effect of the compressibility on the characteristic equation is analyzed. It is shown that the hyperbolicity of the system depends only on the slip velocity and not on the phasic velocities, independently. Moreover, a slip Mach number is defined and a non-dimensional characteristic equation is derived. It is shown that for the small values of slip Mach number the effect of the compressibility on the hyperbolicity can be ignored. To verify the above analysis, the characteristic equation for the two-phase compressible flows is numerically solved and results compared with the values obtained with the analytical solution for incompressible flows. Numerical solution of the two-phase two-fluid model for the benchmark problem is used to further verify the abovementioned analysis. Furthermore, the eigenvalues of the characteristic equation are obtained as a power series expansion about the point where the slip Mach number is zero. These eigenvalues are used to develop a choking criterion for the compressible two-phase flows.

  20. Higher-order compositional modeling of three-phase flow in 3D fractured porous media based on cross-flow equilibrium

    SciTech Connect (OSTI)

    Moortgat, Joachim Firoozabadi, Abbas

    2013-10-01

    Numerical simulation of multiphase compositional flow in fractured porous media, when all the species can transfer between the phases, is a real challenge. Despite the broad applications in hydrocarbon reservoir engineering and hydrology, a compositional numerical simulator for three-phase flow in fractured media has not appeared in the literature, to the best of our knowledge. In this work, we present a three-phase fully compositional simulator for fractured media, based on higher-order finite element methods. To achieve computational efficiency, we invoke the cross-flow equilibrium (CFE) concept between discrete fractures and a small neighborhood in the matrix blocks. We adopt the mixed hybrid finite element (MHFE) method to approximate convective Darcy fluxes and the pressure equation. This approach is the most natural choice for flow in fractured media. The mass balance equations are discretized by the discontinuous Galerkin (DG) method, which is perhaps the most efficient approach to capture physical discontinuities in phase properties at the matrix-fracture interfaces and at phase boundaries. In this work, we account for gravity and Fickian diffusion. The modeling of capillary effects is discussed in a separate paper. We present the mathematical framework, using the implicit-pressure-explicit-composition (IMPEC) scheme, which facilitates rigorous thermodynamic stability analyses and the computation of phase behavior effects to account for transfer of species between the phases. A deceptively simple CFL condition is implemented to improve numerical stability and accuracy. We provide six numerical examples at both small and larger scales and in two and three dimensions, to demonstrate powerful features of the formulation.

  1. How Groundwater Models Work (or Modeling 101)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Works Week on Energy.gov How Energy Works Week on Energy.gov June 16, 2014 - 11:30am Addthis How Energy Works Week on Energy.gov News Media Contact 202-586-4940 Learn the Ins and Outs of Game-Changing Energy Technologies WASHINGTON, D.C. - This week we're celebrating the launch of a new series on Energy.gov: How Energy Works. Each day we will break down the inner workings of a different energy technology -- including particle accelerators, microgrids, 3D printers and wind turbines -- while

  2. FINAL PROJECT REPORT DOE Early Career Principal Investigator Program Project Title: Developing New Mathematical Models for Multiphase Flows Based on a Fundamental Probability Density Function Approach

    SciTech Connect (OSTI)

    Shankar Subramaniam

    2009-04-01

    This final project report summarizes progress made towards the objectives described in the proposal entitled “Developing New Mathematical Models for Multiphase Flows Based on a Fundamental Probability Density Function Approach”. Substantial progress has been made in theory, modeling and numerical simulation of turbulent multiphase flows. The consistent mathematical framework based on probability density functions is described. New models are proposed for turbulent particle-laden flows and sprays.

  3. Enhanced Geothermal Systems Research and Development: Models of Subsurface Chemical Processes Affecting Fluid Flow

    SciTech Connect (OSTI)

    Moller, Nancy; Weare J. H.

    2008-05-29

    Successful exploitation of the vast amount of heat stored beneath the earth’s surface in hydrothermal and fluid-limited, low permeability geothermal resources would greatly expand the Nation’s domestic energy inventory and thereby promote a more secure energy supply, a stronger economy and a cleaner environment. However, a major factor limiting the expanded development of current hydrothermal resources as well as the production of enhanced geothermal systems (EGS) is insufficient knowledge about the chemical processes controlling subsurface fluid flow. With funding from past grants from the DOE geothermal program and other agencies, we successfully developed advanced equation of state (EOS) and simulation technologies that accurately describe the chemistry of geothermal reservoirs and energy production processes via their free energies for wide XTP ranges. Using the specific interaction equations of Pitzer, we showed that our TEQUIL chemical models can correctly simulate behavior (e.g., mineral scaling and saturation ratios, gas break out, brine mixing effects, down hole temperatures and fluid chemical composition, spent brine incompatibilities) within the compositional range (Na-K-Ca-Cl-SO4-CO3-H2O-SiO2-CO2(g)) and temperature range (T < 350°C) associated with many current geothermal energy production sites that produce brines with temperatures below the critical point of water. The goal of research carried out under DOE grant DE-FG36-04GO14300 (10/1/2004-12/31/2007) was to expand the compositional range of our Pitzer-based TEQUIL fluid/rock interaction models to include the important aluminum and silica interactions (T < 350°C). Aluminum is the third most abundant element in the earth’s crust; and, as a constituent of aluminosilicate minerals, it is found in two thirds of the minerals in the earth’s crust. The ability to accurately characterize effects of temperature, fluid mixing and interactions between major rock-forming minerals and hydrothermal and

  4. Ground-water hydraulics of the deep-basin brine aquifer, Palo Duro Basin, Texas panhandle

    SciTech Connect (OSTI)

    Smith, D.A.

    1985-01-01

    The Deep-Basin Brine aquifer of the Palo Duro Basin (Texas Panhandle) underlies thick Permian bedded evaporites that are being evaluated as a potential high-level nuclear waste isolation repository. Potentiometric surface maps of 5 units of the Deep-Basin Brine aquifer were drawn using drill-stem test (DST) pressure data, which were analyzed by a geostatistical technique (kriging) to smooth the large variation in the data. The potentiometric surface maps indicate that the Deep-Basin Brine aquifer could be conceptually modeled as 5 aquifer units; a Lower Permian (Wolfcamp) aquifer, upper and lower Pennsylvanian aquifers, a pre-Pennsylvanian aquifer, and a Pennsylvanian to Wolfcampian granite-wash aquifer. The hydraulic head maps indicate that ground-water flow in each of the units is west to east with a minor northerly component near the Amarillo Uplift, the northern structural boundary of the basin. The Wolfcamp potentiometric surface indicates the strongest component of northerly flow. Inferred flow direction in Pennsylvanian aquifers is easterly, and in the pre-Pennsylvanian aquifer near its pinch-out in the basin center, flow is inferred to be to the north. In the granite-wash aquifer the inferred flow direction is east across the northern edge of the basin and southeast along the Amarillo Uplift.

  5. A numerical investigation of transonic axial compressor rotor flow using a low-Reynolds-number {kappa}-{epsilon} turbulence model

    SciTech Connect (OSTI)

    Arima, T.; Sonoda, T.; Shirotori, M.; Tamura, A.; Kikuchi, K.

    1999-01-01

    The authors have developed a computer simulation code for three-dimensional viscous flow in turbomachinery based on the time-averaged compressible Navier-Stokes equations and a low-Reynolds-number {kappa}-{epsilon} turbulence model. It is described in detail in this paper. The code is used to compute the flow fields for two types of rotor (a transonic fan NASA Rotor 67 and a transonic axial compressor NASA rotor 37), and numerical results are compared to experimental data based on aerodynamic probe and laser anemometer measurements. In the case of Rotor 67, calculated and experimental results are compared under the design speed to validate the code. The calculated results show good agreement with the experimental data, such as the rotor performance map and the spanwise distribution of total pressure, total temperature, and flow angle downstream of the rotor. In the case of Rotor 37, detailed comparisons between the numerical results and the experimental data are made under the design speed condition to assess the overall quality of the numerical solution. Furthermore, comparisons under the part-speed condition are used to investigate a flow field without passage shock. The results are well predicted qualitatively. However, considerable quantitative discrepancies remain in predicting the flow near the tip. In order to assess the predictive capabilities of the developed code, computed flow structures are presented with the experimental data for each rotor and the cause of the discrepancies is discussed.

  6. Bioremediation of contaminated groundwater

    DOE Patents [OSTI]

    Hazen, T.C.; Fliermans, C.B.

    1995-01-24

    An apparatus and method are described for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants. An oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth. Withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene. 3 figures.

  7. Bioremediation of contaminated groundwater

    DOE Patents [OSTI]

    Hazen, Terry C.; Fliermans, Carl B.

    1995-01-01

    An apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid is selected to stimulate the growth and reproduction of indigenous subsurface microorganisms that are capable of degrading the contaminants; an oxygenated fluid is selected to create a generally aerobic environment for these microorganisms to degrade the contaminants, leaving only pockets that are anaerobic. The nutrient fluid is injected periodically while the oxygenated fluid is injected continuously and both are extracted so that both are drawn across the plume. The nutrient fluid stimulates microbial colony growth; withholding it periodicially forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is reduced to an acceptable, preselected level. The nutrient fluid can be methane and the oxygenated fluid air for stimulating production of methanotrophs to break down chlorohydrocarbons, especially trichloroethylene (TCE) and tetrachloroethylene.

  8. Bioremediation of contaminated groundwater

    DOE Patents [OSTI]

    Hazen, T.C.; Fliermans, C.B.

    1994-01-01

    Disclosed is an apparatus and method for in situ remediation of contaminated subsurface soil or groundwater contaminated by chlorinated hydrocarbons. A nutrient fluid (NF) is selected to simulated the growth and reproduction of indigenous subsurface microorganisms capable of degrading the contaminants; an oxygenated fluid (OF) is selected to create an aerobic environment with anaerobic pockets. NF is injected periodically while OF is injected continuously and both are extracted so that both are drawn across the plume. NF stimulates microbial colony growth; withholding it periodically forces the larger, healthy colony of microbes to degrade the contaminants. Treatment is continued until the subsurface concentration of contaminants is acceptable. NF can be methane and OF be air, for stimulating production of methanotrophs to break down chlorohydrocarbons, especially TCE and tetrachloroethylene.

  9. Incorporating a Time Horizon in Rate-of-Return Estimations: Discounted Cash Flow Model in Electric Transmission Rate Cases

    SciTech Connect (OSTI)

    Chatterjee, Bishu; Sharp, Peter A.

    2006-07-15

    Electric transmission and other rate cases use a form of the discounted cash flow model with a single long-term growth rate to estimate rates of return on equity. It cannot incorporate information about the appropriate time horizon for which analysts' estimates of earnings growth have predictive powers. Only a non-constant growth model can explicitly recognize the importance of the time horizon in an ROE calculation. (author)

  10. Implementation and Re nement of a Comprehensive Model for Dense Granular Flows

    SciTech Connect (OSTI)

    Sundaresan, Sankaran

    2015-09-30

    Dense granular ows are ubiquitous in both natural and industrial processes. They manifest three di erent ow regimes, each exhibiting its own dependence on solids volume fraction, shear rate, and particle-level properties. This research project sought to develop continuum rheological models for dense granular ows that bridges multiple regimes of ow, implement them in open-source platforms for gas-particle ows and perform test simulations. The rst phase of the research covered in this project involved implementation of a steady- shear rheological model that bridges quasi-static, intermediate and inertial regimes of ow into MFIX (Multiphase Flow with Interphase eXchanges - a general purpose computer code developed at the National Energy Technology Laboratory). MFIX simulations of dense granular ows in hourglass-shaped hopper were then performed as test examples. The second phase focused on formulation of a modi ed kinetic theory for frictional particles that can be used over a wider range of particle volume fractions and also apply for dynamic, multi- dimensional ow conditions. To guide this work, simulations of simple shear ows of identical mono-disperse spheres were also performed using the discrete element method. The third phase of this project sought to develop and implement a more rigorous treatment of boundary e ects. Towards this end, simulations of simple shear ows of identical mono-disperse spheres con ned between parallel plates were performed and analyzed to formulate compact wall boundary conditions that can be used for dense frictional ows at at frictional boundaries. The fourth phase explored the role of modest levels of cohesive interactions between particles on the dense phase rheology. The nal phase of this project focused on implementation and testing of the modi ed kinetic theory in MFIX and running bin-discharge simulations as test examples.

  11. Soil & Groundwater Home - Hanford Site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Soil & Groundwater Home Soil & Groundwater Home Annual Reports Environmental Data Access Administrative Record Soil & Groundwater Home Email Email Page | Print Print Page | Text Increase Font Size Decrease Font Size Soil & Groundwater Home Annual Reports Environmental Data Access Administrative Record Share on Last Updated 08/28/2016 4:15

  12. SCDAP/RELAP5 Modeling of Fluid Heat Transfer and Flow Losses Through Porous Debris in a Light Water Reactor

    SciTech Connect (OSTI)

    Harvego, Edwin Allan; Siefken, Larry James

    2000-04-01

    The SCDAP/RELAP5 code is being developed at the Idaho National Engineering and Environmental Laboratory under the primary sponsorship of the U.S. Nuclear Regulatory Commission (NRC) to provide best-estimate transient simulations of light water reactor coolant systems during severe accidents. This paper describes the modeling approach used in the SCDAP/RELAP5 code to calculate fluid heat transfer and flow losses through porous debris that has accumulated in the vessel lower head and core regions during the latter stages of a severe accident. The implementation of heat transfer and flow loss correlations into the code is discussed, and calculations performed to assess the validity of the modeling approach are described. The different modes of heat transfer in porous debris include: (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, (5) film boiling, and (6) transition from film boiling to convection to vapor. The correlations for flow losses in porous debris include frictional and form losses. The correlations for flow losses were integrated into the momentum equations in the RELAP5 part of the code. Since RELAP5 is a very general non-homogeneous non-equilibrium thermal-hydraulics code, the resulting modeling methodology is applicable to a wide range of debris thermal-hydraulic conditions. Assessment of the SCDAP/RELAP5 debris bed thermal-hydraulic models included comparisons with experimental measurements and other models available in the open literature. The assessment calculations, described in the paper, showed that SCDAP/RELAP5 is capable of calculating the heat transfer and flow losses occurring in porous debris regions that may develop in a light water reactor during a severe accident.

  13. SCDAP/RELAP5 modeling of fluid heat transfer and flow losses through porous debris in a light water reactor

    SciTech Connect (OSTI)

    E. A. Harvego; L. J. Siefken

    2000-04-02

    The SCDAP/RELAP5 code is being developed at the Idaho National Engineering and Environmental Laboratory under the primary sponsorship of the U.S. Nuclear Regulatory Commission (NRC) to provide best-estimate transient simulations of light water reactor coolant systems during severe accidents. This paper describes the modeling approach used in the SCDAP/RELAP5 code to calculate fluid heat transfer and flow losses through porous debris that has accumulated in the vessel lower head and core regions during the latter stages of a severe accident. The implementation of heat transfer and flow loss correlations into the code is discussed, and calculations performed to assess the validity of the modeling approach are described. The different modes of heat transfer in porous debris include: (1) forced convection to liquid, (2) forced convection to gas, (3) nucleate boiling, (4) transition boiling, (5) film boiling, and (6) transition from film boiling to convection to vapor. The correlations for flow losses in porous debris include frictional and form losses. The correlations for flow losses were integrated into the momentum equations in the RELAP5 part of the code. Since RELAP5 is a very general non-homogeneous non-equilibrium thermal-hydraulics code, the resulting modeling methodology is applicable to a wide range of debris thermal-hydraulic conditions. Assessment of the SCDAP/RELAP5 debris bed thermal-hydraulic models included comparisons with experimental measurements and other models available in the open literature. The assessment calculations, described in the paper, showed that SCDAP/RELAP5 is capable of calculating the heat transfer and flow losses occurring in porous debris regions that may develop in a light water reactor during a severe accident.

  14. Computational Modeling of Fluid Flow through a Fracture in Permeable Rock

    SciTech Connect (OSTI)

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H

    2010-01-01

    Laminar, single-phase, finite-volume solutions to the Navier–Stokes equations of fluid flow through a fracture within permeable media have been obtained. The fracture geometry was acquired from computed tomography scans of a fracture in Berea sandstone, capturing the small-scale roughness of these natural fluid conduits. First, the roughness of the two-dimensional fracture profiles was analyzed and shown to be similar to Brownian fractal structures. The permeability and tortuosity of each fracture profile was determined from simulations of fluid flow through these geometries with impermeable fracture walls. A surrounding permeable medium, assumed to obey Darcy’s Law with permeabilities from 0.2 to 2,000 millidarcies, was then included in the analysis. A series of simulations for flows in fractured permeable rocks was performed, and the results were used to develop a relationship between the flow rate and pressure loss for fractures in porous rocks. The resulting frictionfactor, which accounts for the fracture geometric properties, is similar to the cubic law; it has the potential to be of use in discrete fracture reservoir-scale simulations of fluid flow through highly fractured geologic formations with appreciable matrix permeability. The observed fluid flow from the surrounding permeable medium to the fracture was significant when the resistance within the fracture and the medium were of the same order. An increase in the volumetric flow rate within the fracture profile increased by more than 5% was observed for flows within high permeability-fractured porous media.

  15. Hanford Site Groundwater Monitoring for Fiscal Year 2000

    SciTech Connect (OSTI)

    Hartman, Mary J.; Morasch, Launa F.; Webber, William D.

    2001-03-01

    This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 2000 on the U.S. Department of Energy's Hanford Site, Washington. The most extensive contaminant plumes are tritium, iodine-129, and nitrate, which all had multiple sources and are very mobile in groundwater. Carbon tetrachloride and associated organic constituents form a relatively large plume beneath the central part of the Site. Hexavalent chromium is present in smaller plumes beneath the reactor areas along the river and beneath the central part of the site. Strontium-90 exceeds standards beneath each of the reactor areas, and technetium-99 and uranium are present in the 200 Areas. RCRA groundwater monitoring continued during fiscal year 2000. Vadose zone monitoring, characterization, remediation, and several technical demonstrations were conducted in fiscal year 2000. Soil gas monitoring at the 618-11 burial ground provided a preliminary indication of the location of tritium in the vadose zone and in groundwater. Groundwater modeling efforts focused on 1) identifying and characterizing major uncertainties in the current conceptual model and 2) performing a transient inverse calibration of the existing site-wide model. Specific model applications were conducted in support of the Hanford Site carbon tetrachloride Innovative Treatment Remediation Technology; to support the performance assessment of the Immobilized Low-Activity Waste Disposal Facility; and in development of the System Assessment Capability, which is intended to predict cumulative site-wide effects from all significant Hanford Site contaminants.

  16. Uranium Fate and Transport Modeling, Guterl Specialty Steel Site, New York - 13545

    SciTech Connect (OSTI)

    Frederick, Bill; Tandon, Vikas

    2013-07-01

    The Former Guterl Specialty Steel Corporation Site (Guterl Site) is located 32 kilometers (20 miles) northeast of Buffalo, New York, in Lockport, Niagara County, New York. Between 1948 and 1952, up to 15,875 metric tons (35 million pounds) of natural uranium metal (U) were processed at the former Guterl Specialty Steel Corporation site in Lockport, New York. The resulting dust, thermal scale, mill shavings and associated land disposal contaminated both the facility and on-site soils. Uranium subsequently impacted groundwater and a fully developed plume exists below the site. Uranium transport from the site involves legacy on-site pickling fluid handling, the leaching of uranium from soil to groundwater, and the groundwater transport of dissolved uranium to the Erie Canal. Groundwater fate and transport modeling was performed to assess the transfer of dissolved uranium from the contaminated soils and buildings to groundwater and subsequently to the nearby Erie Canal. The modeling provides a tool to determine if the uranium contamination could potentially affect human receptors in the vicinity of the site. Groundwater underlying the site and in the surrounding area generally flows southeasterly towards the Erie Canal; locally, groundwater is not used as a drinking water resource. The risk to human health was evaluated outside the Guterl Site boundary from the possibility of impacted groundwater discharging to and mixing with the Erie Canal waters. This condition was evaluated because canal water is infrequently used as an emergency water supply for the City of Lockport via an intake located approximately 122 meters (m) (400 feet [ft]) southeast of the Guterl Site. Modeling was performed to assess whether mixing of groundwater with surface water in the Erie Canal could result in levels of uranium exceeding the U.S. Environmental Protection Agency (USEPA) established drinking water standard for total uranium; the Maximum Concentration Limit (MCL). Geotechnical test

  17. Framework for a Risk-Informed Groundwater Compliance Strategy for Corrective Action Unit 98: Frenchman Flat, Nevada National Security Site, Nye County, Nevada, Revision 1

    SciTech Connect (OSTI)

    Marutzky, Sam

    2010-09-01

    Note: This document was prepared before the NTS was renamed the Nevada National Security Site (August 23, 2010); thus, all references to the site herein remain NTS. Corrective Action Unit (CAU) 98, Frenchman Flat, at the Nevada Test Site (NTS) was the location of ten underground nuclear tests between 1965 and 1971. As a result, radionuclides were released in the subsurface in the vicinity of the test cavities. Corrective Action Unit 98 and other CAUs at the NTS and offsite locations are being investigated. The Frenchman Flat CAU is one of five Underground Test Area (UGTA) CAUs at the NTS that are being evaluated as potential sources of local or regional impact to groundwater resources. For UGTA sites, including Frenchman Flat, contamination in and around the test cavities will not be remediated because it is technologically infeasible due to the depth of the test cavities (150 to 2,000 feet [ft] below ground surface) and the volume of contaminated groundwater at widely dispersed locations on the NTS. Instead, the compliance strategy for these sites is to model contaminant flow and transport, estimate the maximum spatial extent and volume of contaminated groundwater (over a period of 1,000 years), maintain institutional controls, and restrict access to potentially contaminated groundwater at areas where contaminants could migrate beyond the NTS boundaries.

  18. Key factors for determining groundwater impacts due to leakage from geologic carbon sequestration reservoirs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carroll, Susan A.; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenxue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-09-07

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow groundwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models, referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could resultmore » from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which no impact to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur. To facilitate this, multi-phase flow and reactive transport simulations and emulations were developed for two classes of aquifers, considering uncertainty in leakage source terms and aquifer hydrogeology. We targeted an unconfined fractured carbonate aquifer based on the Edwards aquifer in Texas and a confined alluvium aquifer based on the High Plains Aquifer in Kansas, which share characteristics typical of many drinking water aquifers in the United States. The hypothetical leakage scenarios centered on the notion that wellbores are the most likely

  19. Key factors for determining groundwater impacts due to leakage from geologic carbon sequestration reservoirs

    SciTech Connect (OSTI)

    Carroll, Susan A.; Keating, Elizabeth; Mansoor, Kayyum; Dai, Zhenxue; Sun, Yunwei; Trainor-Guitton, Whitney; Brown, Chris; Bacon, Diana

    2014-09-07

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow groundwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models, referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which no impact to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur. To facilitate this, multi-phase flow and reactive transport simulations and emulations were developed for two classes of aquifers, considering uncertainty in leakage source terms and aquifer hydrogeology. We targeted an unconfined fractured carbonate aquifer based on the Edwards aquifer in Texas and a confined alluvium aquifer based on the High Plains Aquifer in Kansas, which share characteristics typical of many drinking water aquifers in the United States. The hypothetical leakage scenarios centered on the notion that wellbores

  20. Groundwater Report Goes Online, Interactive

    Broader source: Energy.gov [DOE]

    RICHLAND, Wash. – EM’s Richland Operations Office (RL) has moved its 1,200-page annual report on groundwater monitoring to a fully online and interactive web application.

  1. Ground-water in Texas

    SciTech Connect (OSTI)

    Ward-McLemore, E.

    1985-01-01

    Amount 61% of the water used by Texans is ground-water. Some areas, both municipal and rural, depend entirely on ground-water. In many areas long term withdrawal is lowering the water levels, causing surface land subsidence, salt-water encroachment, and reducing future reservoir availability. The increasing probability of seepage from radioactive and toxic wastes, herbicide residues, septic systems, and oilfield brines is threatening dangerous contamination of fresh ground-water reservoirs. The Texas Department of Water Resources, the Texas Department of Health, State and private colleges and universities, the US Geological Survey, the Environmental Protection Agency, various underground water districts, among others, are cooperating with concerned hydrologists in a concentrated program to increase the efficiency of ground-water use and development, preserve the aquifer reservoirs, and decrease the pollution potential. 88 references.

  2. Drift flux model as approximation of two fluid model for two phase dispersed and slug flow in tube

    SciTech Connect (OSTI)

    Nigmatulin, R.I.

    1995-09-01

    The analysis of one-dimensional schematizing for non-steady two-phase dispersed and slug flow in tube is presented. Quasi-static approximation, when inertia forces because of the accelerations of the phases may be neglected, is considered. Gas-liquid bubbly and slug vertical upward flows are analyzed. Non-trivial theoretical equations for slip velocity for these flows are derived. Juxtaposition of the derived equations for slip velocity with the famous Zuber-Findlay correlation as cross correlation coefficients is criticized. The generalization of non-steady drift flux Wallis theory taking into account influence of wall friction on the bubbly or slug flows for kinematical waves is considered.

  3. NNSS Hosts Groundwater Open House

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Survey of the Bay Area NNSS Hosts Groundwater Open House A RSL helicopter spent part of August conducting aerial radiation flyovers in the California Bay Area. The team rocked the competition and chiseled out an impressive second place finish recently in the Security Protection Officer competition. Groundwater was the topic of discussion at a recent open house. See page 12. See page 5. See page 8. Enterprise Publication "ONEVOICE" Replaces Spotlight and SiteLines The Nevada National

  4. Groundwater contamination from stormwater infiltration

    SciTech Connect (OSTI)

    Pitt, R.; Clark, S.; Parmer, K.

    1995-10-01

    The research summarized here was conducted during the first year of a 3-yr cooperative agreement (CR819573) to identify and control stormwater toxicants, especially those adversely affecting groundwater. The purpose of this research effort was to review the groundwater contamination literature as it relates to stormwater. Prior to urbanization groundwater is recharged by rainfall-runoff and snowmelt infiltrating through pervious surfaces including grasslands and woods. This infiltrating water is relatively uncontaminated. Urbanization, however, reduces the permeable soil surface area through which recharge by infiltration occurs. This results in much less groundwater recharge and greatly increased surface runoff. In addition the waters available for recharge carry increased quantities of pollutants. With urbanization, waters having elevated contaminant concentrations also recharge groundwater including effluent from domestic septic tanks, wastewater from percolation basins and industrial waste injection wells, infiltrating stormwater, and infiltrating water from agricultural irrigation. The areas of main concern that are covered by this paper are: the source of the pollutants, stormwater constituents having a high potential to contaminate groundwater, and the treatment necessary for stormwater.

  5. Hoe Creek groundwater restoration, 1989

    SciTech Connect (OSTI)

    Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

    1990-01-01

    During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

  6. Evaluation of Groundwater Movement in the Frenchman Flat CAU Using Geochemical and Isotopic Analysis

    SciTech Connect (OSTI)

    R. Hershey; J. Thomas; T. Rose; J. Paces; I. Farnham; C. Benedict, Jr.

    2005-03-01

    The principal pathway for radionuclide migration from underground tests in Frenchman Flat, on the Nevada Test Site, to the accessible environment is groundwater flow. Two potential pathways for radionuclide transport via groundwater have been identified from hydrologic data: (1) radionuclide transport downward from the alluvial and volcanic aquifers into the underlying carbonate aquifer; and (2) radionuclide transport laterally to the carbonate aquifer surrounding Frenchman Flat. This report presents an evaluation of geochemical and environmental isotopic data to test these potential pathways and to identify other groundwater flowpaths in, and out of, Frenchman Flat.

  7. Fluid flow modeling of resin transfer molding for composite material wind turbine blade structures.

    SciTech Connect (OSTI)

    Cairns, Douglas S. (Montana State University, Bozeman, MT); Rossel, Scott M. (Montana State University, Bozeman, MT)

    2004-06-01

    Resin transfer molding (RTM) is a closed mold process for making composite materials. It has the potential to produce parts more cost effectively than hand lay-up or other methods. However, fluid flow tends to be unpredictable and parts the size of a wind turbine blade are difficult to engineer without some predictive method for resin flow. There were five goals of this study. The first was to determine permeabilities for three fabrics commonly used for RTM over a useful range of fiber volume fractions. Next, relations to estimate permeabilities in mixed fabric lay-ups were evaluated. Flow in blade substructures was analyzed and compared to predictions. Flow in a full-scale blade was predicted and substructure results were used to validate the accuracy of a full-scale blade prediction.

  8. Final report on isotope tracer investigations in the Forebay of the Orange County groundwater basin.

    SciTech Connect (OSTI)

    Davisson, M; Woodside, G

    2003-12-13

    California is currently faced with some critical decisions about water resource infrastructure development in highly urbanized regions, whose outcome will dictate the future long-term viability of plentiful water. Among these is developing and safely implementing the reuse of advanced treated waste water. One of the most reliable strategies for this water resource is its indirect reuse via groundwater recharge and storage, with particular emphasis on supplementing annual water demand or during drought relief. The Orange County Water District (District) is currently implementing the first phase of a large-scale water reuse project that will advance-treat up to 60 million gallons per day of waste water and recharge it into existing percolation basins in the Forebay region of the Orange County groundwater basin. In order for the District to protect public health, the fate and potability of this recharged waste water needs to be understood. In particular, the direction and rates of flow into underlying aquifers need to be characterized so that changes in water quality can be quantified between the recharge basins and points of production. Furthermore, to ensure compliance to California Department of Health Services (DHS) draft regulations, the direction and rate of recharged waste water from these basins need to be understood to sufficient detail that small mixtures can be delineated in monitoring and production wells. Under proposed DHS guidelines, consumptive use of recycled water is permissive only if its residence time in an aquifer exceeds a specified six-month time-frame. DHS guidelines also limit the percentage of recycled water at production wells. However, attaining such detail using current hydrogeological and computer-assisted modeling tools is either cost-prohibitive or results in uncertainties too large to achieve regulatory confidence. To overcome this technical barrier, the District funded Lawrence Livermore National Laboratory (LLNL) from 1995-2001 to

  9. 2012 Groundwater Monitoring Report Project Shoal Area Subsurface Corrective Action Unit 447

    SciTech Connect (OSTI)

    2013-03-01

    The Project Shoal Area (PSA) in Nevada was the site of a 12-kiloton underground nuclear test in 1963. Although the surface of the site has been remediated, investigation of groundwater contamination resulting from the test is still in the corrective action process. Annual sampling and hydraulic head monitoring are conducted at the site as part of the subsurface corrective action strategy. Analytical results from the 2012 monitoring are consistent with those of the previous years, with tritium detected only in well HC-4. The tritium concentration in groundwater from well HC-4 remains far below the U.S. Environmental Protection Agency-established maximum contaminant level of 20,000 picocuries per liter. Concentrations of total uranium and gross alpha were also detected during this monitoring period, with uranium accounting for nearly all the gross alpha activity. The total uranium concentrations obtained from this monitoring period were consistent with previous results and reflect a slightly elevated natural uranium concentration, consistent with the mineralized geologic terrain. Isotopic ratios of uranium also indicate a natural source of uranium in groundwater, as opposed to a nuclear-test-related source. Water level trends obtained from the 2012 water level data were consistent with those of previous years. The corrective action strategy for the PSA is currently focused on revising the site conceptual model (SCM) and evaluating the adequacy of the current monitoring well network. Some aspects of the SCM are known; however, two major concerns are the uncertainty in the groundwater flow direction and the cause of rising water levels in site wells west of the shear zone. Water levels have been rising in the site wells west of the shear zone since the first hydrologic characterization wells were installed in 1996. While water levels in wells west of the shear zone continue to rise, the rate of increase is less than in previous years. The SCM will be revised, and an

  10. Predictions of flow through an isothermal serpentine passage with linear eddy-viscosity Reynolds Averaged Navier Stokes models.

    SciTech Connect (OSTI)

    Laskowski, Gregory Michael

    2005-12-01

    Flows with strong curvature present a challenge for turbulence models, specifically eddy viscosity type models which assume isotropy and a linear and instantaneous equilibrium relation between stress and strain. Results obtained from three different codes and two different linear eddy viscosity turbulence models are compared to a DNS simulation in order to gain some perspective on the turbulence modeling capability of SIERRA/Fuego. The Fuego v2f results are superior to the more common two-layer k-e model results obtained with both a commercial and research code in terms of the concave near wall behavior predictions. However, near the convex wall, including the separated region, little improvement is gained using the v2f model and in general the turbulent kinetic energy prediction is fair at best.

  11. EM Soil and Groundwater Database Reports | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    EM Soil and Groundwater Database Reports EM Soil and Groundwater Database Reports Brookhaven National Laboratory - HFBR Tritium Groundwater Database Report - Brookhaven National ...

  12. A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...

    Open Energy Info (EERE)

    surface infiltration, and geothermal conditions are incorporated into the model. The reliability and accuracy of the model have been the subject of a comprehensive model...

  13. Flow and Transport in the Hanford 300 Area Vadose Zone-Aquifer-River System

    SciTech Connect (OSTI)

    Waichler, Scott R.; Yabusaki, Steven B.

    2005-07-13

    Contaminant migration in the 300 Area unconfined aquifer is strongly coupled to fluctuations in the Columbia River stage. To better understand the interaction between the river, aquifer, and vadose zone, a 2-D saturated-unsaturated flow and transport model was developed for a vertical cross-section aligned west-east across the Hanford Site 300 Area, nearly perpendicular to the river. The model was used to investigate water flow and tracer transport in the vadose zone-aquifer-river flow system, in support of the ongoing study of the 300 Area uranium plume. The STOMP simulator was used to model 1-year from 3/1/92 to 2/28/93, a period when hourly data were available for both groundwater and river levels. Net water flow to the river (per 1-meter width of shoreline) was 182 m3/y in the base case, but the cumulative exchange or total flow back and forth across the riverbed was 30 times greater. The low river case had approximately double the net water and Groundwater tracer flux into the river as compared to the base case.

  14. Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3??MHz frequency at atmospheric pressure

    SciTech Connect (OSTI)

    Punjabi, Sangeeta B.; Sahasrabudhe, S. N.; Das, A. K.; Joshi, N. K.; Mangalvedekar, H. A.; Kothari, D. C.

    2014-01-15

    This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50?kW DC power and 3?MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User Defined Function. A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications.

  15. Computational Fluid Dynamics Modeling of the Bonneville Project: Tailrace Spill Patterns for Low Flows and Corner Collector Smolt Egress

    SciTech Connect (OSTI)

    Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.; Perkins, William A.

    2010-12-01

    In 2003, an extension of the existing ice and trash sluiceway was added at Bonneville Powerhouse 2 (B2). This extension started at the existing corner collector for the ice and trash sluiceway adjacent to Bonneville Powerhouse 2 and the new sluiceway was extended to the downstream end of Cascade Island. The sluiceway was designed to improve juvenile salmon survival by bypassing turbine passage at B2, and placing these smolt in downstream flowing water minimizing their exposure to fish and avian predators. In this study, a previously developed computational fluid dynamics model was modified and used to characterized tailrace hydraulics and sluiceway egress conditions for low total river flows and low levels of spillway flow. STAR-CD v4.10 was used for seven scenarios of low total river flow and low spill discharges. The simulation results were specifically examined to look at tailrace hydraulics at 5 ft below the tailwater elevation, and streamlines used to compare streamline pathways for streamlines originating in the corner collector outfall and adjacent to the outfall. These streamlines indicated that for all higher spill percentage cases (25% and greater) that streamlines from the corner collector did not approach the shoreline at the downstream end of Bradford Island. For the cases with much larger spill percentages, the streamlines from the corner collector were mid-channel or closer to the Washington shore as they moved downstream. Although at 25% spill at 75 kcfs total river, the total spill volume was sufficient to "cushion" the flow from the corner collector from the Bradford Island shore, areas of recirculation were modeled in the spillway tailrace. However, at the lowest flows and spill percentages, the streamlines from the B2 corner collector pass very close to the Bradford Island shore. In addition, the very flow velocity flows and large areas of recirculation greatly increase potential predator exposure of the spillway passed smolt. If there is

  16. DFNWorks. A discrete fracture network framework for modeling subsurface flow and transport

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-08-10

    DFNWorks is a parallalized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using dfnGen, which combines fram (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs on the basis of site specific data with the LaGriT meshing toolbox to create a high-quality computational mesh representation, specifically a conforming Delaunay triangulation suitable for high performance computingmore » finite volume solvers, of the DFN in an intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code pflotran. A Lagrangian approach to simulating transport through the DFN is adopted within dfnTrans, which is an extension of the walkabout particle tracking method to determine pathlines through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.« less

  17. Design, testing and two-dimensional flow modeling of a multiple-disk fan

    SciTech Connect (OSTI)

    Engin, Tahsin; Oezdemir, Mustafa; Cesmeci, Sevki

    2009-11-15

    A multiple-disk Tesla type fan has been designed, tested and analyzed two-dimensionally using the conservation of angular momentum principle. Experimental results showed that such multiple-disk fans exhibited exceptionally low performance characteristics, which could be attributed to the low viscosity, tangential nature of the flow, and large mechanical energy losses at both suction and discharge sections that are comparable to the total input power. By means of theoretical analysis, local and overall shearing stresses on the disk surfaces have been determined based on tangential and radial velocity distributions of the air flow of different volume flow rates at prescribed disk spaces and rotational speeds. Then the total power transmitted by rotating disks to air flow, and the power acquired by the air flow in the gap due to transfer of angular momentum have been obtained by numerically integrating shearing stresses over the disk surfaces. Using the measured shaft and hydraulic powers, these quantities were utilized to evaluate mechanical energy losses associated with the suction and discharge sections of the fan. (author)

  18. DFNWorks. A discrete fracture network framework for modeling subsurface flow and transport

    SciTech Connect (OSTI)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-08-10

    DFNWorks is a parallalized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using dfnGen, which combines fram (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs on the basis of site specific data with the LaGriT meshing toolbox to create a high-quality computational mesh representation, specifically a conforming Delaunay triangulation suitable for high performance computing finite volume solvers, of the DFN in an intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code pflotran. A Lagrangian approach to simulating transport through the DFN is adopted within dfnTrans, which is an extension of the walkabout particle tracking method to determine pathlines through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.

  19. dfnWorks: A discrete fracture network framework for modeling subsurface flow and transport

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-11-01

    DFNWORKS is a parallelized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using DFNGEN, which combines FRAM (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs with the LaGriT meshing toolbox to create a high-quality computational mesh representation. The representation produces a conforming Delaunay triangulation suitable for high performance computing finite volume solvers in anmore » intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code PFLOTRAN. A Lagrangian approach to simulating transport through the DFN is adopted within DFNTRANS to determine pathlines and solute transport through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.« less

  20. dfnWorks: A discrete fracture network framework for modeling subsurface flow and transport

    SciTech Connect (OSTI)

    Hyman, Jeffrey D.; Karra, Satish; Makedonska, Nataliia; Gable, Carl W.; Painter, Scott L.; Viswanathan, Hari S.

    2015-11-01

    DFNWORKS is a parallelized computational suite to generate three-dimensional discrete fracture networks (DFN) and simulate flow and transport. Developed at Los Alamos National Laboratory over the past five years, it has been used to study flow and transport in fractured media at scales ranging from millimeters to kilometers. The networks are created and meshed using DFNGEN, which combines FRAM (the feature rejection algorithm for meshing) methodology to stochastically generate three-dimensional DFNs with the LaGriT meshing toolbox to create a high-quality computational mesh representation. The representation produces a conforming Delaunay triangulation suitable for high performance computing finite volume solvers in an intrinsically parallel fashion. Flow through the network is simulated in dfnFlow, which utilizes the massively parallel subsurface flow and reactive transport finite volume code PFLOTRAN. A Lagrangian approach to simulating transport through the DFN is adopted within DFNTRANS to determine pathlines and solute transport through the DFN. Example applications of this suite in the areas of nuclear waste repository science, hydraulic fracturing and CO2 sequestration are also included.

  1. Factors governing sustainable groundwater pumping near a river

    SciTech Connect (OSTI)

    Zhang, Y.; Hubbard, S.S.; Finsterle, S.

    2011-01-15

    The objective of this paper is to provide new insights into processes affecting riverbank filtration (RBF). We consider a system with an inflatable dam installed for enhancing water production from downstream collector wells. Using a numerical model, we investigate the impact of groundwater pumping and dam operation on the hydrodynamics in the aquifer and water production. We focus our study on two processes that potentially limit water production of an RBF system: the development of an unsaturated zone and riverbed clogging. We quantify river clogging by calibrating a time-dependent riverbed permeability function based on knowledge of pumping rate, river stage, and temperature. The dynamics of the estimated riverbed permeability reflects clogging and scouring mechanisms. Our results indicate that (1) riverbed permeability is the dominant factor affecting infiltration needed for sustainable RBF production; (2) dam operation can influence pumping efficiency and prevent the development of an unsaturated zone beneath the riverbed only under conditions of sufficient riverbed permeability; (3) slow river velocity, caused by dam raising during summer months, may lead to sedimentation and deposition of fine-grained material within the riverbed, which may clog the riverbed, limiting recharge to the collector wells and contributing to the development of an unsaturated zone beneath the riverbed; and (4) higher river flow velocities, caused by dam lowering during winter storms, scour the riverbed an thus increase its permeability. These insights can be used as the basis for developing sustainable water management of a RBF system.

  2. Groundwater monitoring plan for the Hanford Site 200 Area Treated Effluent Disposal Facility

    SciTech Connect (OSTI)

    DB Barnett

    2000-05-17

    Seven years of groundwater monitoring at the 200 Area Treated Effluent Disposal Facility (TEDF) have shown that the uppermost aquifer beneath the facility is unaffected by TEDF effluent. Effluent discharges have been well below permitted and expected volumes. Groundwater mounding from TEDF operations predicted by various models has not been observed, and waterlevels in TEDF wells have continued declining with the dissipation of the nearby B Pond System groundwater mound. Analytical results for constituents with enforcement limits indicate that concentrations of all these are below Practical Quantitation Limits, and some have produced no detections. Likewise, other constituents on the permit-required list have produced results that are mostly below sitewide background. Comprehensive geochemical analyses of groundwater from TEDF wells has shown that most constituents are below background levels as calculated by two Hanford Site-wide studies. Additionally, major ion proportions and anomalously low tritium activities suggest that groundwater in the aquifer beneath the TEDF has been sequestered from influences of adjoining portions of the aquifer and any discharge activities. This inference is supported by recent hydrogeologic investigations which indicate an extremely slow rate of groundwater movement beneath the TEDF. Detailed evaluation of TEDF-area hydrogeology and groundwater geochemistry indicate that additional points of compliance for groundwater monitoring would be ineffective for this facility, and would produce ambiguous results. Therefore, the current groundwater monitoring well network is retained for continued monitoring. A quarterly frequency of sampling and analysis is continued for all three TEDF wells. The constituents list is refined to include only those parameters key to discerning subtle changes in groundwater chemistry, those useful in detecting general groundwater quality changes from upgradient sources, or those retained for comparison with end

  3. UNSAT-H Version 3.0: Unsaturated Soil Water and Heat Flow Model Theory, User Manual, and Examples

    SciTech Connect (OSTI)

    MJ Fayer

    2000-06-12

    The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve the above goals for assessing water dynamics and estimating recharge rates, the UNSAT-H model addresses soil water infiltration, redistribution, evaporation, plant transpiration, deep drainage, and soil heat flow as one-dimensional processes. The UNSAT-H model simulates liquid water flow using Richards' equation (Richards 1931), water vapor diffusion using Fick's law, and sensible heat flow using the Fourier equation. This report documents UNSAT-H .Version 3.0. The report includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plants, and the code manual. Version 3.0 is an, enhanced-capability update of UNSAT-H Version 2.0 (Fayer and Jones 1990). New features include hysteresis, an iterative solution of head and temperature, an energy balance check, the modified Picard solution technique, additional hydraulic functions, multiple-year simulation capability, and general enhancements.

  4. MODELING STRATEGIES FOR UNSTEADY TURBULENT FLOWS IN THE LOWER PLENUM OF THE VHTR

    SciTech Connect (OSTI)

    Richard W. Johnson

    2006-09-01

    Validation simulations are presented for turbulent flow in a staggered tube bank, geometry similar to that in the lower plenum of a block very high temperature reactor. Steady 2D RANS predictions are compared to unsteady 2D RANS results and experiment. The unsteady calculations account for the fact that nonturbulent fluctuations (due to vortex-shedding) are present in the flow. The unsteady computations are shown to predict the mean variables and the total shear stress quite well. Previous workers have presented results that indicated that 3D simulations were necessary to obtain reasonable results. Best practices are based on requirements for the ASME Journal of Fluids Engineering.

  5. An investigation of the effect of diffusivity on the transport and spread of contaminants in groundwater systems

    SciTech Connect (OSTI)

    Nutter, D.; Stewart, M.; Muyshondt, A.

    1997-07-01

    Contaminant transport in groundwater is modeled using an advection diffusion equation. The diffusion component of the model is due to molecular diffusion and advection through the flow passages in the soil matrix which are smaller than the resolvable length scales. In addition to the physical diffusion, the advection/diffusion equation requires a certain amount of diffusion for the governing equations to be stable. If there is insufficient physical diffusion the cell Peclet number is less than 2 and oscillations in the solution occur. Balance numerical diffusion must be supplied for a stable solution. Numerical simulations of contaminant transport in groundwater flows must therefore include accurate models of as many of three forms of diffusion. One represents the subscale fluid path diffusion (either tensor, vector, or scalar in form), another is the scalar molecular diffusion (scalar), and the numerical stabilizing diffusion (again either tensor, vector, or scalar in form). The final result must reasonably model contaminant spread and transport for the predictions to be useful. In the literature, measurements of contaminant diffusivity are usually made using one dimensional experiments. Because of the dependence on higher level models to capture all of the physics in contaminant transport, it is to validate these models using realistic multidimensional geometries with comparisons to experimental data. Here, the effects of different diffusion models are examined and compared for two important cases. The first is a contaminant plume originating at the surface and extracted at a drain. The second case is an isolated region of contamination which is advected and diffused towards the drain. In the second case, qualitative comparisons can be made with limited visualization data. These results will eventually be used with a comprehensive experimental program to validate models of diffusion transport.

  6. On the Modeling of Local Neutronically-Coupled Flow-Induced Oscillations in Advanced Boiling Water Reactors

    SciTech Connect (OSTI)

    Aniel-Buchheit, Sylvie; Podowski, Michael Z.

    2006-07-01

    The purpose of this paper is to discuss the development in progress of a complete space- and time-dependent model of the coupled neutron kinetic and reactor thermal-hydraulics. The neutron kinetics model is based on two-group diffusion equations with Doppler and void reactivity feedback effects. This model is coupled with the model of two-phase flow and heat transfer in parallel coolant channels. The modeling concepts considered for this purpose include one-dimensional drift flux and two-fluid models, as well a CFD model implemented in the NPHASE advanced computational multiphase fluid dynamics (CMFD) computer code. Two methods of solution for the overall model are proposed. One is based on direct numerical integration of the spatially-discretized governing equations. The other approach is based on a quasi-analytical modal approach to the neutronics model, in which a complete set of eigenvectors is found for step-wise temporal changes of the cross-sections of core materials (fuel and coolant/moderator). The issues investigated in the paper include details of model formulation, as well as the results of calculations for neutronically-coupled density-wave oscillations. (authors)

  7. Observation and modeling of mixing-layer development in high-energy-density, blast-wave-driven shear flow

    SciTech Connect (OSTI)

    Di Stefano, C. A. Kuranz, C. C.; Klein, S. R.; Drake, R. P.; Malamud, G.; Henry de Frahan, M. T.; Johnsen, E.; Shimony, A.; Shvarts, D.; Smalyuk, V. A.; Martinez, D.

    2014-05-15

    In this work, we examine the hydrodynamics of high-energy-density (HED) shear flows. Experiments, consisting of two materials of differing density, use the OMEGA-60 laser to drive a blast wave at a pressure of ∼50 Mbar into one of the media, creating a shear flow in the resulting shocked system. The interface between the two materials is Kelvin-Helmholtz unstable, and a mixing layer of growing width develops due to the shear. To theoretically analyze the instability's behavior, we rely on two sources of information. First, the interface spectrum is well-characterized, which allows us to identify how the shock front and the subsequent shear in the post-shock flow interact with the interface. These observations provide direct evidence that vortex merger dominates the evolution of the interface structure. Second, simulations calibrated to the experiment allow us to estimate the time-dependent evolution of the deposition of vorticity at the interface. The overall result is that we are able to choose a hydrodynamic model for the system, and consequently examine how well the flow in this HED system corresponds to a classical hydrodynamic description.

  8. A pore-scale model of two-phase flow in water-wet rock

    SciTech Connect (OSTI)

    Silin, Dmitriy; Patzek, Tad

    2009-02-01

    A finite-difference discretization of Stokes equations is used to simulate flow in the pore space of natural rocks. Numerical solutions are obtained using the method of artificial compressibility. In conjunction with Maximal Inscribed Spheres method, these computations produce relative permeability curves. The results of computations are in agreement with laboratory measurements.

  9. INTEC Groundwater Monitoring Report 2006

    SciTech Connect (OSTI)

    J. R. Forbes S. L. Ansley M. Leecaster

    2007-02-01

    This report summarizes 2006 perched water and groundwater monitoring activities at the Idaho Nuclear Technology and Engineering Center (INTEC) located at the Idaho National Laboratory (INL). During 2006, groundwater samples were collected from a total of 22 Snake River Plain Aquifer (SRPA) monitoring wells, plus six aquifer wells sampled for the Idaho CERCLA Disposal Facility (ICDF) monitoring program. In addition, perched water samples were collected from 21 perched wells and 19 suction lysimeters. Groundwater and perched water samples were analyzed for a suite of radionuclides and inorganic constituents. Laboratory results in this report are compared to drinking water maximum contaminant levels (MCLs). Such comparison is for reference only and it should be noted that the Operable Unit 3-13 Record of Decision does not require that perched water comply with drinking water standards.

  10. Groundwater Availability Within the Salton Sea Basin Final Report

    SciTech Connect (OSTI)

    Tompson, A; Demir, Z; Moran, J; Mason, D; Wagoner, J; Kollet, S; Mansoor, K; McKereghan, P

    2008-01-11

    in the Salton Sea Basin is the subject of the project described in this report. Much of the project work was done in cooperation with the US Bureau of Reclamation, Lower Colorado Region Office ('Reclamation'), which manages the Salton Sea Restoration project for the US Department of the Interior, and complements other recent assessment efforts (e.g., Imperial County, 1995). In this context, the notion of groundwater availability is defined by four separate, but interrelated concepts or components: (1) Volume and Capacity--This refers to the volume of groundwater available in storage in (or the related storage capacity of) the sediments and geologic media that comprise a groundwater basin. The volume of groundwater in a basin will vary in time as a function of recharge, well production, and land subsidence. (2) Producibility--This refers to the ease or difficulty of extracting groundwater in a basin from wells. Groundwater producibility will be affected by well depth and the formation permeability surrounding the open intervals in wells. (3) Quality--This refers to the extent that water produced from wells is potable or otherwise suitable for domestic or other uses. It may also refer to the chemical compositions of groundwater that are unrelated to potability or suitability issues. Groundwater quality will be affected by its residence time and flow pathway in the formation and will also be influenced by the quality of its original source before entering the groundwater regime. (4) Renewability and Recharge--This refers to the extent that groundwater is recharged to the basin as part of the natural hydrologic cycle or other artificial means. Groundwater renewability is normally a function of recharge derived from precipitation (and thus a function of regional climate), but may also be affected in local areas by irrigation, leaking canals, aquifer storage and recovery operations, and so forth. Along with the other factors, renewability will strongly affect how much

  11. Summary of Vadose -- Zone Conceptual Models for Flow and Contaminant Transport and 1999 - 2003 Progress on Resolving Deficiencies in Understanding the Vadose Zone at the INEEL

    SciTech Connect (OSTI)

    Robert C. Starr; Dana L. Dettmers; Brennon R. Orr; Thomas R. Wood

    2003-12-01

    The thick vadose zone that underlies the Idaho National Engineering and Environmental Laboratory has been recognized both as an avenue through which contaminants disposed at or near the ground surface can migrate to groundwater in the underlying Eastern Snake River Plain aquifer, and as a barrier to the movement of contaminants into the aquifer. Flow and contaminant transport in the vadose zone at the INEEL is complicated by the highly heterogeneous nature of the geologic framework and by the variations in the behavior of different contaminants in the subsurface. The state of knowledge concerning flow and contaminant transport in the vadose zone at and near the INEEL IN 1999 was summarized in Deficiencies in Vadose Zone Understanding at the Idaho National Engineering and Environmental Laboratory (Wood et al., 2000). These authors identified deficiencies in knowledge of flow and contaminant transport processes in the vadose zone, and provided recommendations for additional work that should be conducted to address these deficiencies. In the period since (Wood et al., 2000) was prepared, research has been published that, to some degree, address these deficiencies. This document provides a bibliography of reports, journal articles, and conference proceedings published 1999 through mid-2003 that are relevant to the vadose zone at or near the INEEL and provides a brief description of each work. Publications that address specific deficiencies or recommendations are identified, and pertinent information from selected publications is presented.

  12. Shiprock Archived Soil & Groundwater Master Reports | Department of Energy

    Office of Environmental Management (EM)

    Shiprock Archived Soil & Groundwater Master Reports Shiprock Archived Soil & Groundwater Master Reports Shiprock Archived Soil & Groundwater Master Reports Shiprock - Shiprock (19.31 KB) More Documents & Publications Slick Rock Archived Soil & Groundwater Master Reports Tuba City Archived Soil & Groundwater Master Reports Spook Archived Soil & Groundwater Master Reports

  13. Spook Archived Soil & Groundwater Master Reports | Department of Energy

    Office of Environmental Management (EM)

    Spook Archived Soil & Groundwater Master Reports Spook Archived Soil & Groundwater Master Reports Spook Archived Soil & Groundwater Master Reports Spook - Spook (17.91 KB) More Documents & Publications Tuba City Archived Soil & Groundwater Master Reports Slick Rock Archived Soil & Groundwater Master Reports Weldon Spring Site Archived Soil & Groundwater Master Reports

  14. Hanford Story: Groundwater - Questions - Hanford Site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Hanford Story Hanford Story: Groundwater - Questions The Hanford Story Email Email Page | Print Print Page | Text Increase Font Size Decrease Font Size How did contamination get into the groundwater beneath the Hanford Site? What has caused the level of contamination to decrease over the years? What is the 2015 vision for Hanford? What is the goal of the water treatment systems and facilities? What is being done to treat groundwater to remove contamination? Is contaminated groundwater

  15. Development of a three-phase reacting flow computer model for analysis of petroleum cracking

    SciTech Connect (OSTI)

    Chang, S.L.; Lottes, S.A.; Petrick, M.

    1995-07-01

    A general computational fluid dynamics computer code (ICRKFLO) has been developed for the simulation of the multi-phase reacting flow in a petroleum fluid catalytic cracker riser. ICRKFLO has several unique features. A new integral reaction submodel couples calculations of hydrodynamics and cracking kinetics by making the calculations more efficient in achieving stable convergence while still preserving the major physical effects of reaction processes. A new coke transport submodel handles the process of coke formation in gas phase reactions and the subsequent deposition on the surface of adjacent particles. The code was validated by comparing with experimental results of a pilot scale fluid cracker unit. The code can predict the flow characteristics of gas, liquid, and particulate solid phases, vaporization of the oil droplets, and subsequent cracking of the oil in a riser reactor, which may lead to a better understanding of the internal processes of the riser and the impact of riser geometry and operating parameters on the riser performance.

  16. Considerations for developing models of multiphase flow in deformable porous media.

    SciTech Connect (OSTI)

    Martinez, Mario J.; Stone, Charles Michael

    2008-09-01

    This document summarizes research and planning for the development of a numerical simulation capability for nonisothermal multiphase, multicomponent transport in heterogeneous deformable porous materials. Particular attention is given to describing a mathematical formulation for flow in deformable media and for numerical techniques for dealing with phase transitions. A development plan is formulated to provide a computational capability motivated by current and future needs in geosystems management for energy security.

  17. Fully Coupled Geomechanics and Discrete Flow Network Modeling of Hydraulic Fracturing for Geothermal Applications

    SciTech Connect (OSTI)

    Fu, P; Johnson, S M; Hao, Y; Carrigan, C R

    2011-01-18

    The primary objective of our current research is to develop a computational test bed for evaluating borehole techniques to enhance fluid flow and heat transfer in enhanced geothermal systems (EGS). Simulating processes resulting in hydraulic fracturing and/or the remobilization of existing fractures, especially the interaction between propagating fractures and existing fractures, represents a critical goal of our project. To this end, we are continuing to develop a hydraulic fracturing simulation capability within the Livermore Distinct Element Code (LDEC), a combined FEM/DEM analysis code with explicit solid-fluid mechanics coupling. LDEC simulations start from an initial fracture distribution which can be stochastically generated or upscaled from the statistics of an actual fracture distribution. During the hydraulic stimulation process, LDEC tracks the propagation of fractures and other modifications to the fracture system. The output is transferred to the Non-isothermal Unsaturated Flow and Transport (NUFT) code to capture heat transfer and flow at the reservoir scale. This approach is intended to offer flexibility in the types of analyses we can perform, including evaluating the effects of different system heterogeneities on the heat extraction rate as well as seismicity associated with geothermal operations. This paper details the basic methodology of our approach. Two numerical examples showing the capability and effectiveness of our simulator are also presented.

  18. RDX in Groundwater | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    RDX in Groundwater RDX in Groundwater Topic: Tim Goering LANL, Provided Information on the RDX Groundwater Plume that is Located Under Technical Area 16 at Los Alamos. Information on Monitoring and Possible Clean-up Solutions was Given. RDX Update - July 8, 2015 (1.97

  19. Reaching Site Closure for Groundwater under Multiple Regulatory Agencies

    SciTech Connect (OSTI)

    Glucksberg, N.; Shephard, Gene; Peters, Jay; Couture, B.

    2008-01-15

    Groundwater at the Connecticut Yankee Atomic Power Company (CYAPCO) Haddam Neck Plant (HNP) requires investigation of both radionuclides and chemical constituents in order to achieve closure. Cleanup criteria for groundwater are regulated both by federal and state agencies. These requirements vary in both numerical values as well as the duration of post remediation monitoring. The only consistent requirement is the development of a site conceptual model and an understanding of the hydrogeologic conditions that will govern contaminant transport and identify potential receptors. To successfully reach closure under each agency, it is paramount to understand the different requirements during the planning stages of the investigation. Therefore, the conceptual site model, groundwater transport mechanisms, and potential receptors must be defined. Once the hydrogeology is understood, a long term groundwater program can then be coordinated to meet each regulatory agency requirement to both terminate the NRC license and reach site closure under RCRA. Based on the different criteria, the CTDEP-LR (or RSR criteria) are not only bounding, but also requires the longest duration. As with most decommissioning efforts, regulatory attention is focused on the NRC, however, with the recent industry initiatives based on concern of tritium releases to groundwater at other plants, it is likely that the USEPA and state agencies may continue to drive site investigations. By recognizing these differences, data quality objectives can include all agency requirements, thus minimizing rework or duplicative efforts. CYAPCO intends to complete groundwater monitoring for the NRC and CTDEP-RD by July 2007. However, because shallow remediations are still being conducted, site closure under USEPA and CTDEP-LR is projected to be late 2011.

  20. Numerical implementation, verification and validation of two-phase flow four-equation drift flux model with Jacobian-free Newton–Krylov method

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zou, Ling; Zhao, Haihua; Zhang, Hongbin

    2016-08-24

    This study presents a numerical investigation on using the Jacobian-free Newton–Krylov (JFNK) method to solve the two-phase flow four-equation drift flux model with realistic constitutive correlations (‘closure models’). The drift flux model is based on Isshi and his collaborators’ work. Additional constitutive correlations for vertical channel flow, such as two-phase flow pressure drop, flow regime map, wall boiling and interfacial heat transfer models, were taken from the RELAP5-3D Code Manual and included to complete the model. The staggered grid finite volume method and fully implicit backward Euler method was used for the spatial discretization and time integration schemes, respectively. Themore » Jacobian-free Newton–Krylov method shows no difficulty in solving the two-phase flow drift flux model with a discrete flow regime map. In addition to the Jacobian-free approach, the preconditioning matrix is obtained by using the default finite differencing method provided in the PETSc package, and consequently the labor-intensive implementation of complex analytical Jacobian matrix is avoided. Extensive and successful numerical verification and validation have been performed to prove the correct implementation of the models and methods. Code-to-code comparison with RELAP5-3D has further demonstrated the successful implementation of the drift flux model.« less

  1. Sanitary landfill groundwater monitoring data

    SciTech Connect (OSTI)

    Thompson, C.Y.

    1992-05-01

    This report for first quarter 1992 contains sanitary landfill groundwater monitoring data for the Savannah River Plant. The data tables presented in this report are copies of draft analytical results and therefore do contain errors. These errors will be corrected when the finalized data is received from the laboratory.

  2. Removing High Explosives from Groundwater

    Broader source: Energy.gov [DOE]

    LOS ALAMOS, N.M. – In an initiative supported by EM, Los Alamos National Laboratory’s Corrective Actions Program is addressing high explosive contamination in surface water and groundwater at a location this summer in the forests surrounding the laboratory.

  3. TH-A-9A-01: Active Optical Flow Model: Predicting Voxel-Level Dose Prediction in Spine SBRT

    SciTech Connect (OSTI)

    Liu, J; Wu, Q.J.; Yin, F; Kirkpatrick, J; Cabrera, A; Ge, Y

    2014-06-15

    Purpose: To predict voxel-level dose distribution and enable effective evaluation of cord dose sparing in spine SBRT. Methods: We present an active optical flow model (AOFM) to statistically describe cord dose variations and train a predictive model to represent correlations between AOFM and PTV contours. Thirty clinically accepted spine SBRT plans are evenly divided into training and testing datasets. The development of predictive model consists of 1) collecting a sequence of dose maps including PTV and OAR (spinal cord) as well as a set of associated PTV contours adjacent to OAR from the training dataset, 2) classifying data into five groups based on PTV's locations relative to OAR, two “Top”s, “Left”, “Right”, and “Bottom”, 3) randomly selecting a dose map as the reference in each group and applying rigid registration and optical flow deformation to match all other maps to the reference, 4) building AOFM by importing optical flow vectors and dose values into the principal component analysis (PCA), 5) applying another PCA to features of PTV and OAR contours to generate an active shape model (ASM), and 6) computing a linear regression model of correlations between AOFM and ASM.When predicting dose distribution of a new case in the testing dataset, the PTV is first assigned to a group based on its contour characteristics. Contour features are then transformed into ASM's principal coordinates of the selected group. Finally, voxel-level dose distribution is determined by mapping from the ASM space to the AOFM space using the predictive model. Results: The DVHs predicted by the AOFM-based model and those in clinical plans are comparable in training and testing datasets. At 2% volume the dose difference between predicted and clinical plans is 4.2±4.4% and 3.3±3.5% in the training and testing datasets, respectively. Conclusion: The AOFM is effective in predicting voxel-level dose distribution for spine SBRT. Partially supported by NIH/NCI under grant

  4. Numerical and Physical Modelling of Bubbly Flow Phenomena - Final Report to the Department of Energy

    SciTech Connect (OSTI)

    Andrea Prosperetti

    2004-12-21

    This report describes the main features of the results obtained in the course of this project. A new approach to the systematic development of closure relations for the averaged equations of disperse multiphase flow is outlined. The focus of the project is on spatially non-uniform systems and several aspects in which such systems differ from uniform ones are described. Then, the procedure used in deriving the closure relations is given and some explicit results shown. The report also contains a list of publications supported by this grant and a list of the persons involved in the work.

  5. Hanford Site groundwater monitoring for Fiscal Year 1997

    SciTech Connect (OSTI)

    Hartman, M.J.; Dresel, P.E.

    1998-02-01

    This report presents the results of groundwater and vadose-zone monitoring for fiscal year (FY) 1997 on the Hanford Site, Washington. Soil-vapor extraction continued in the 200-West Area to remove carbon tetrachloride from the vadose zone. Characterization and monitoring of the vadose zone comprised primarily spectral gamma logging, soil-vapor monitoring, and analysis and characterization of sediments sampled below a vadose-zone monitoring well. Source-term analyses for strontium-90 in 100-N Area vadose-zone sediments were performed using recent groundwater-monitoring data and knowledge of strontium`s ion-exchange properties. Water-level monitoring was performed to evaluate groundwater-flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Water levels over most of the Hanford Site continued to decline between June 1996 and June 1997. Water levels near the Columbia River increased during this period because the river stage was unusually high. Groundwater chemistry was monitored to track the extent of contamination, to note trends, and to identify emerging groundwater-quality problems. The most widespread radiological contaminant plumes were tritium and iodine-129. Concentrations of technetium-99, uranium, strontium-90, and carbon-14 also exceeded drinking water standards in smaller plumes. Plutonium and cesium-137 exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in U.S. Department of Energy Order 5400.5 were exceeded for tritium, uranium, strontium-90, and plutonium in small plumes or single wells. Nitrate is the most extensive chemical contaminant. Carbon tetrachloride, chloroform, chromium, cis-1,2-dichloroethylene, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Cyanide concentrations were elevated in one area but were below the maximum contaminant level.

  6. Comparison between a spectral and PDF model for turbulent reacting flows.

    SciTech Connect (OSTI)

    Vaithianathan, T.; Collins, L. R.; Ulitsky, M. S.

    2002-01-01

    This study compares the performance of a probability density function (PDF) model and a spectral model (known as the eddy damped quasi-normal Markovian or EDQNM model) for the case of two initially unmixed reactants undergoing a finite-rate bimolecular reaction. The two models were chosen because they involve complimentary treatments of the nonlinearities and mixing terms. That is, nonlinearities are exactly treated in the PDF and mixing is modeled, whereas the opposite is true for EDQNM. The predictions of the two models are compared to direct numerical simulations. The results show that the PDF model is capable of describing the mixing of the major species reasonably well, but fails to describe the correlations between the reactants and the products even qualitatively. This suggests that the mixing model in the PDF is adequate for describing mixing between major species, but is incapable of describing mixing of the more spatially segregated product species. The EDQNM model does a slightly better job of describing the mixing of reactant species and a much better job of describing mixing of the product species. Presumably the improvement is associated with the more accurate description of the interscale dynamics that are especially important for the segregated products. The implication is that a model that combines the strengths of the EDQNM for describing mixing and the PDF for describing the nonlinearities would yield the best of both worlds.

  7. Effect of faulting on ground-water movement in the Death Valley region, Nevada and California

    SciTech Connect (OSTI)

    Faunt, C.C.

    1997-12-31

    This study characterizes the hydrogeologic system of the Death Valley region, an area covering approximately 100,000 square kilometers. The study also characterizes the effects of faults on ground-water movement in the Death Valley region by synthesizing crustal stress, fracture mechanics,a nd structural geologic data. The geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. Faulting and associated fracturing is pervasive and greatly affects ground-water flow patterns. Faults may become preferred conduits or barriers to flow depending on whether they are in relative tension, compression, or shear and other factors such as the degree of dislocations of geologic units caused by faulting, the rock types involved, the fault zone materials, and the depth below the surface. The current crustal stress field was combined with fault orientations to predict potential effects of faults on the regional ground-water flow regime. Numerous examples of fault-controlled ground-water flow exist within the study area. Hydrologic data provided an independent method for checking some of the assumptions concerning preferential flow paths. 97 refs., 20 figs., 5 tabs.

  8. Factors influencing the transport of actinides in the groundwater environment. Final report

    SciTech Connect (OSTI)

    Sheppard, J.C.; Kittrick, J.A.

    1983-07-31

    This report summarizes investigations of factors that significantly influence the transport of actinide cations in the groundwater environment. Briefly, measurements of diffusion coefficients for Am(III), Cm(III), and Np(V) in moist US soils indicated that diffusion is negligible compared to mass transport in flowing groundwater. Diffusion coefficients do, however, indicate that, in the absence of flowing water, actinide elements will migrate only a few centimeters in a thousand years. The remaining investigations were devoted to the determination of distribution ratios (K/sub d/s) for representative US soils, factors influencing them, and chemical and physical processes related to transport of actinides in groundwaters. The computer code GARD was modified to include complex formation to test the importance of humic acid complexing on the rate of transport of actinides in groundwaters. Use of the formation constant and a range of humic acid, even at rather low concentrations of 10/sup -5/ to 10/sup -6/ molar, significantly increases the actinide transport rate in a flowing aquifer. These computer calculations show that any strong complexing agent will have a similar effect on actinide transport in the groundwater environment. 32 references, 9 figures.

  9. DESCRIPTION OF MODELING ANALYSES IN SUPPORT OF THE 200-ZP-1 REMEDIAL DESIGN/REMEDIAL ACTION

    SciTech Connect (OSTI)

    VONGARGEN BH

    2009-11-03

    The Feasibility Study/or the 200-ZP-1 Groundwater Operable Unit (DOE/RL-2007-28) and the Proposed Plan/or Remediation of the 200-ZP-1 Groundwater Operable Unit (DOE/RL-2007-33) describe the use of groundwater pump-and-treat technology for the 200-ZP-1 Groundwater Operable Unit (OU) as part of an expanded groundwater remedy. During fiscal year 2008 (FY08), a groundwater flow and contaminant transport (flow and transport) model was developed to support remedy design decisions at the 200-ZP-1 OU. This model was developed because the size and influence of the proposed 200-ZP-1 groundwater pump-and-treat remedy will have a larger areal extent than the current interim remedy, and modeling is required to provide estimates of influent concentrations and contaminant mass removal rates to support the design of the aboveground treatment train. The 200 West Area Pre-Conceptual Design/or Final Extraction/Injection Well Network: Modeling Analyses (DOE/RL-2008-56) documents the development of the first version of the MODFLOW/MT3DMS model of the Hanford Site's Central Plateau, as well as the initial application of that model to simulate a potential well field for the 200-ZP-1 remedy (considering only the contaminants carbon tetrachloride and technetium-99). This document focuses on the use of the flow and transport model to identify suitable extraction and injection well locations as part of the 200 West Area 200-ZP-1 Pump-and-Treat Remedial Design/Remedial Action Work Plan (DOEIRL-2008-78). Currently, the model has been developed to the extent necessary to provide approximate results and to lay a foundation for the design basis concentrations that are required in support of the remedial design/remediation action (RD/RA) work plan. The discussion in this document includes the following: (1) Assignment of flow and transport parameters for the model; (2) Definition of initial conditions for the transport model for each simulated contaminant of concern (COC) (i.e., carbon

  10. PIV Experiments to Measure Flow Phenomena in a Scaled Model of a VHTR Lower Plenum

    SciTech Connect (OSTI)

    Hugh M. McIlroy, Jr.; Donald M. McEligot; Richard R. Schultz; Daniel Christensen; Robert J. Pink; Ryan C. Johnson

    2006-09-01

    A report of experimental data collected at the Matched-Index-of-Refraction (MIR) Laboratory in support of contract DE-AC07-05ID14517 and the INL Standard Problem on measurements of flow phenomena occurring in a lower plenum of a typical prismatic VHTR concept reactor to assess CFD code is presented. Background on the experimental setup and procedures is provided along with several samples of data obtained from the 3-D PIV system and an assessment of experimental uncertainty is provided. Data collected in this study include 3-dimensional velocity-field descriptions of the flow in all four inlet jets and the entire lower plenum with inlet jet Reynolds numbers (ReJet) of approximately 4300 and 12,400. These investigations have generated over 2 terabytes of data that has been processed to describe the various velocity components in formats suitable for external release and archived on removable hard disks. The processed data from both experimental studies are available in multi-column text format.

  11. Final report on the Groundwater Isotope Project in the Brentwood Region of East Contra Costa County, California

    SciTech Connect (OSTI)

    Davisson, M.L.; Campbell, K.R.

    1995-05-01

    Groundwater in the Brentwood region has been characterized using isotope hydrology techniques and have addressed resource issues regarding the future sustainability of groundwater, maintenance of existing supplies, and exploration of new supplies. The stable isotopes of oxygen and hydrogen indicate that groundwater is derived from two sources: ancient rain recharge, and recharge of agricultural irrigation water. Rain derived groundwater ages range from <1000 to {approximately}12,000 years old. Agricultural recharge groundwater is <80 years and has recharged much of the basin on average to {approximately}125 fbs. The agricultural water recharges >10 times faster than natural rain water and hence, represents the principal recharge component. The agricultural recharge at the present time provides groundwater quantities to the basin that exceed the yearly water supply demand. With increasing urban development and retiring agricultural land, the availability of groundwater will decrease. Safe yield projections for the groundwater have been modeled to show that safe groundwater yields range between 30 to 120 acre-ft/mi{sup 2} per year for a population of 70,000 people. This will only account for {approximately}3 to 11 % of the total water demand. Furthermore, much of this groundwater may need well head treatment for water quality problems.

  12. 2012 Groundwater Monitoring Report Central Nevada Test Area, Subsurface Corrective Action Unit 443

    SciTech Connect (OSTI)

    2013-04-01

    The Central Nevada Test Area was the site of a 0.2- to 1-megaton underground nuclear test in 1968. The surface of the site has been closed, but the subsurface is still in the corrective action process. The corrective action alternative selected for the site was monitoring with institutional controls. Annual sampling and hydraulic head monitoring are conducted as part of the subsurface corrective action strategy. The site is currently in the fourth year of the 5-year proof-of-concept period that is intended to validate the compliance boundary. Analytical results from the 2012 monitoring are consistent with those of previous years. Tritium remains at levels below the laboratory minimum detectable concentration in all wells in the monitoring network. Samples collected from reentry well UC-1-P-2SR, which is not in the monitoring network but was sampled as part of supplemental activities conducted during the 2012 monitoring, indicate concentrations of tritium that are consistent with previous sampling results. This well was drilled into the chimney shortly after the detonation, and water levels continue to rise, demonstrating the very low permeability of the volcanic rocks. Water level data from new wells MV-4 and MV-5 and recompleted well HTH-1RC indicate that hydraulic heads are still recovering from installation and testing. Data from wells MV-4 and MV-5 also indicate that head levels have not yet recovered from the 2011 sampling event during which several thousand gallons of water were purged. It has been recommended that a low-flow sampling method be adopted for these wells to allow head levels to recover to steady-state conditions. Despite the lack of steady-state groundwater conditions, hydraulic head data collected from alluvial wells installed in 2009 continue to support the conceptual model that the southeast-bounding graben fault acts as a barrier to groundwater flow at the site.

  13. High pressure annular two-phase flow in a narrow duct. Part 1: Local measurements in the droplet field, and Part 2: Three-field modeling

    SciTech Connect (OSTI)

    Trabold, T.A.; Kumar, R.

    1999-07-01

    In Part 1, detailed measurements were made in a high pressure, adiabatic (boiled at the inlet) annular flow in a narrow, high aspect ratio duct using a gamma densitometer, hot-film anemometer and high-speed video photography. Measurements of void fraction, droplet frequency, velocity, drop size, and interfacial area concentration have been made to support the three field computational capability. An important aspect of this testing is the use of a modeling fluid (R-134a) in a vertical duct which permits visual access in annular flow. This modeling fluid accurately simulates the low liquid-to-vapor density ratio of steam-water flows at high pressures. These measurements have been taken in a narrow duct of hydraulic diameter 4.85 mm, and a cross-section aspect ratio of 22.5. However, the flow displays profiles of various shapes not only in the narrow dimension, but also in the width dimension. In particular, the shape of the droplet profiles depends on the entrained droplet flux from the edges in the vapor core. The average diameter from these profiles compare well with the models developed in the literature. Interfacial area concentration for these low density ratio flows is higher than the highest concentration reported for air-water flows. Video records show that along with the bow-shaped waves, three-dimensional {lambda}-shaped waves appear in annular flows for high flow rates. Part 2 outlines the development of a three-field modeling approach in annular flow and the predictive capability of an analysis code. Models have been developed here or adapted from the literature for the thin film near the wall as well as the droplets in the vapor core, and have been locally applied in a fully developed, two-phase adiabatic boiling annular flow in a duct heated at the inlet at high pressure. Numerical results have been obtained using these models that are required for the closure of the continuity and momentum equations. The two-dimensional predictions are compared with

  14. GWVis: A Tool for Comparative Ground-Water Data Visualization

    SciTech Connect (OSTI)

    Best, Daniel M.; Lewis, Robert R.

    2010-11-01

    The Ground-Water Visualization application (GWVis) presents ground-water data visually in order to educate the public on ground-water issues. It is also intended for presentations to government and other funding agencies. Current three dimensional models of ground-water are overly complex, while the two dimensional representations (i.e., on paper) are neither comprehensive, nor engaging. At present, GWVis operates on water head elevation data over a given time span, together with a matching (fixed) underlying geography. Two elevation scenarios are compared with each other, typically a control data set (actual field data) and a simulation. Scenario comparison can be animated for the time span provided. We developed GWVis using the Python programming language, associated libraries, and pyOpenGL extension packages to improve performance and control of attributes of the mode (such as color, positioning, scale, and interpolation). GWVis bridges the gap between two dimensional and dynamic three dimensional research visualizations by providing an intuitive, interactive design that allows participants to view the model from different perspectives and to infer information about scenarios. By incorporating scientific data in an environment that can be easily understood, GWVis allows the information to be presented to a large audience base.

  15. A coke/soot formation model for multiphase reacting flow simulation

    SciTech Connect (OSTI)

    Chang, S.L.; Lottes, S.A.; Petrick, M.; Zhou, C.Q. |

    1997-03-01

    Coke is a by-product in petroleum fluid catalytic cracking (FCC) processes. The concentration of coke in an FCC riser reactor is a critical parameter used to evaluate the riser performance. A coke formation and transport model was developed. It was incorporated into a computational fluid dynamic (CFD) computer code, ICRKFLO, to simulate the coke formation processes in an FCC riser reactor. Based on a similar process, a soot formation model can be derived from the coke formation model and used for diesel combustion processes, where soot is emitted as one of the primary pollutants.

  16. Groundwater Annual Status Report for Fiscal Year 1998

    SciTech Connect (OSTI)

    A. K. Stoker; A. S. Johnson; B. D. Newman; B. M. Gallaher; C. L. Nylander; D. B. Rogers; D. E. Broxton; D. Katzman; E. H. Keating; G. L. Cole; K. A. Bitner; K. I. Mullen; P. Longmire; S. G. McLin; W. J. Stone

    1999-04-01

    Groundwater protection activities and hydrogeologic characterization studies are conducted at LANL annually. A summary of fiscal year 1998 results and findings shows increased understanding of the hydrogeologic environment beneath the Pajarito Plateau and significant refinement to elements of the LANL Hydrogeologic Conceptual Model pertaining to areas and sources of recharge to the regional aquifer. Modeling, drilling, monitoring, and data collection activities are proposed for fiscal year 1999.

  17. Groundwater Annual Status Report for Fiscal Year 1999

    SciTech Connect (OSTI)

    C. L. Nylander; K. A. Bitner; K. Henning; A. S. Johnson; E. H. Keating; P. Longmire; B. D. Newman; B. Robinson; D. B. Rogers; W. J. Stone; D. Vaniman

    2000-03-01

    Groundwater protection activities and hydrogeologic characterization studies are conducted at Los Alamos National Laboratory annually. A summary of fiscal year 1999 results and findings shows increased understanding of the hydrogeologic environment beneath the Pajarito Plateau and significant refinement to elements of the LANL. Hydrogeologic Conceptual Model pertaining to areas and sources of recharge to the regional aquifer. Modeling, drilling, monitoring, and data collection activities are proposed for fiscal year 2000.

  18. RELAP5 Model Description and Validation for the BR2 Loss-of-Flow Experiments

    SciTech Connect (OSTI)

    Licht, J. R.; Dionne, B.; Van den Branden, G.; Sikik, E.; Koonen, E.

    2015-07-01

    This paper presents a description of the RELAP5 model, the calibration method used to obtain the minor loss coefficients from the available hydraulic data and the LOFA simulation results compared to the 1963 experimental tests for HEU fuel.

  19. Work plan for the Oak Ridge National Laboratory groundwater program: Continuous groundwater collection

    SciTech Connect (OSTI)

    NONE

    1995-08-01

    The continuous collection of groundwater data is a basic and necessary part of Lockeheed Martin Energy Systems` ORNL Environmental Restoration Area-Wide Groundwater Program. Continuous groundwater data consist primarily of continually recorded groundwater levels, and in some instances, specific conductivity, pH, and/or temperature measurements. These data will be collected throughout the ORNL site. This Work Plan (WP) addresses technical objectives, equipment requirements, procedures, documentation requirements, and technical instructions for the acquisition of the continuous groundwater data. Intent of this WP is to provide an approved document that meets all the necessary requirements while retaining the flexibility necessary to effectively address ORNL`s groundwater problems.

  20. Overview of heat transfer and fluid flow problem areas encountered in stirling engine modeling

    SciTech Connect (OSTI)

    Tew, R.C. Jr.

    1988-02-01

    NASA Lewis Research Center has been managing Stirling engine development programs for over a decade. In addition to contractual programs, this work has included in-house engine testing and development of engine computer models. Attempts to validate Stirling engine computer models with test data have demonstrated that engine thermodynamic losses need better characterization. Various Stirling engine thermodynamic losses and efforts that are underway to characterize these losses are discussed.

  1. Subsurface Flow and Contaminant Transport Documentation and User's Guide

    SciTech Connect (OSTI)

    Aleman, S.E.

    1999-07-28

    This report documents a finite element code designed to model subsurface flow and contaminant transport, named FACT. FACT is a transient three-dimensional, finite element code designed to simulate isothermal groundwater flow, moisture movement, and solute transport in variably saturated and fully saturated subsurface porous media. The code is designed specifically to handle complex multi-layer and/or heterogeneous aquifer systems in an efficient manner and accommodates a wide range of boundary conditions. Additionally, 1-D and 2-D (in Cartesian coordinates) problems are handled in FACT by simply limiting the number of elements in a particular direction(s) to one. The governing equations in FACT are formulated only in Cartesian coordinates.

  2. Direct Push Groundwater Circulation Wells for Remediation of BTEX and Volatile Organics

    SciTech Connect (OSTI)

    Borden, R. E.; Cherry, Robert Stephen

    2000-09-01

    Direct push groundwater circulation wells (DP-GCW) are a promising technology for remediation of groundwater contaminated with dissolved hydrocarbons and chlorinated solvents. In these wells, groundwater is withdrawn from the formation at the bottom of the well, aerated and vapor stripped and injected back into the formation at or above the water table. Previous field studies have shown that: (a) GCWs can circulate significant volumes of groundwater; and (b) GCWs can effectively remove volatile compounds and add oxygen. In this work, we describe the development and field-testing of a system of DP-GCWs for remediation of volatile organics such as benzene, toluene, ethylbenzene, and toluene (BTEX). The GCWs were constructed with No. 20 slotted well screen (2.4 cm ID) and natural sand pack extending from 1.5 to 8.2 m below grade. Air is introduced ~7.5 m below grade via 0.6 cm tubing. Approximately 15% of the vertical length of the air supply tubing is wrapped in tangled mesh polypropylene geonet drainage fabric to provide surface area for biological growth and precipitation of oxidized iron. These materials were selected to allow rapid installation of the GCWs using 3.8 cm direct push Geoprobe® rods, greatly reducing well installation costs. Laboratory testing of these sparged wells and computational fluid dynamics (CFD) modeling showed that these wells, although they used only about 1 L/min of air, could circulate about 1 L/min of water through the surrounding aquifer. This flow was sufficient to capture all of a flowing contaminant if the wells are sufficiently closely together, about 1 meter on center depending on the air flow rate supplied, in a line across the plume. The CFD work showed the details of this ability to capture, and also showed that unforeseen heterogeneities in the aquifer such as a gradient of permeability or a thin impermeable layer (such as a clay layer) did not prevent the system from working largely as intended. The system was tested in a

  3. Direct Push Groundwater Circulation Wells for Remediation of BTEX and Volatile Organics

    SciTech Connect (OSTI)

    Borden, R.C.; Cherry, R.S.

    2000-09-30

    Direct push groundwater circulation wells (DP-GCW) are a promising technology for remediation of groundwater contaminated with dissolved hydrocarbons and chlorinated solvents. In these wells, groundwater is withdrawn from the formation at the bottom of the well, aerated and vapor stripped and injected back into the formation at or above the water table. Previous field studies have shown that: (a) GCWs can circulate significant volumes of groundwater; and (b) GCWs can effectively remove volatile compounds and add oxygen. In this work, we describe the development and field-testing of a system of DP-GCWs for remediation of volatile organics such as benzene, toluene, ethylbenzene, and toluene (BTEX). The GCWs were constructed with No. 20 slotted well screen (2.4 cm ID) and natural sand pack extending from 1.5 to 8.2 m below grade. Air is introduced {approximately}7.5 m below grade via 0.6 cm tubing. Approximately 15% of the vertical length of the air supply tubing is wrapped in tangled mesh polypropylene geonet drainage fabric to provide surface area for biological growth and precipitation of oxidized iron. These materials were selected to allow rapid installation of the GCWs using 3.8 cm direct push Geoprobe{reg_sign} rods, greatly reducing well installation costs. Laboratory testing of these sparged wells and computational fluid dynamics (CFD) modeling showed that these wells, although they used only about 1 L/min of air, could circulate about 1 L/min of water through the surrounding aquifer. This flow was sufficient to capture all of a flowing contaminant if the wells are sufficiently closely together, about 1 meter on center depending on the air flow rate supplied, in a line across the plume. The CFD work showed the details of this ability to capture, and also showed that unforeseen heterogeneities in the aquifer such as a gradient of permeability or a thin impermeable layer (such as a clay layer) did not prevent the system from working largely as intended. The

  4. Groundwater Under Review Marathon Man

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Under Review Marathon Man NNSS team welcomes peer review of groundwater program. Nevada Teams compete in the National Science Bowl in Washington. NSTec runner finishes first Boston Marathon. See page 7. See page 6. NNSS Roads Getting a Fresh Makeover Highways, roads, parking lots - any place that has seen at least 60 years of traffic like the Nevada National Security Site (NNSS) has - will experience some normal wear and tear. That is why National Security Technologies (NSTec) is doing some

  5. Experimental and Kinetic Modeling Study of Extinction and Ignition of Methyl Decanoate in Laminar Nonpremixed Flows

    SciTech Connect (OSTI)

    Seshadri, K; Lu, T; Herbinet, O; Humer, S; Niemann, U; Pitz, W J; Law, C K

    2008-01-09

    Methyl decanoate is a large methyl ester that can be used as a surrogate for biodiesel. In this experimental and computational study, the combustion of methyl decanoate is investigated in nonpremixed, nonuniform flows. Experiments are performed employing the counterflow configuration with a fuel stream made up of vaporized methyl decanoate and nitrogen, and an oxidizer stream of air. The mass fraction of fuel in the fuel stream is measured as a function of the strain rate at extinction, and critical conditions of ignition are measured in terms of the temperature of the oxidizer stream as a function of the strain rate. It is not possible to use a fully detailed mechanism for methyl decanoate to simulate the counterflow flames because the number of species and reactions is too large to employ with current flame codes and computer resources. Therefore a skeletal mechanism was deduced from a detailed mechanism of 8555 elementary reactions and 3036 species using 'directed relation graph' method. This skeletal mechanism has only 713 elementary reactions and 125 species. Critical conditions of ignition were calculated using this skeletal mechanism and are found to agree well with experimental data. The predicted strain rate at extinction is found to be lower than the measurements. In general, the methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  6. Field evaluation of a horizontal well recirculation system for groundwater treatment: Field demonstration at X-701B Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    SciTech Connect (OSTI)

    Korte, N.; Muck, M.; Kearl, P.; Siegrist, R.; Schlosser, R.; Zutman, J.; Houk, T.

    1998-08-01

    This report describes the field-scale demonstration performed as part of the project, In Situ Treatment of Mixed Contaminants in Groundwater. This project was a 3{1/2} year effort comprised of laboratory work performed at Oak Ridge National Laboratory and fieldwork performed at the US Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS). The overall goal of the project was to evaluate in situ treatment of groundwater using horizontal recirculation coupled with treatment modules. Specifically, horizontal recirculation was tested because of its application to thin, interbedded aquifer zones. Mixed contaminants were targeted because of their prominence at DOE sites and because they cannot be treated with conventional methods. The project involved several research elements, including treatment process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and full-scale testing at a contaminated site. This report presents the results of the work at the contaminated site, X-701B at PORTS. Groundwater contamination at X-701B consists of trichloroethene (TCE) (concentrations up to 1800 mg/L) and technetium-998 (Tc{sup 99}) (activities up to 926 pCi/L).

  7. DEVELOPMENT OF PLASTICITY MODEL USING NON ASSOCIATED FLOW RULE FOR HCP MATERIALS INCLUDING ZIRCONIUM FOR NUCLEAR APPLICATIONS

    SciTech Connect (OSTI)

    Michael V. Glazoff; Jeong-Whan Yoon

    2013-08-01

    In this report (prepared in collaboration with Prof. Jeong Whan Yoon, Deakin University, Melbourne, Australia) a research effort was made to develop a non associated flow rule for zirconium. Since Zr is a hexagonally close packed (hcp) material, it is impossible to describe its plastic response under arbitrary loading conditions with any associated flow rule (e.g. von Mises). As a result of strong tension compression asymmetry of the yield stress and anisotropy, zirconium displays plastic behavior that requires a more sophisticated approach. Consequently, a new general asymmetric yield function has been developed which accommodates mathematically the four directional anisotropies along 0 degrees, 45 degrees, 90 degrees, and biaxial, under tension and compression. Stress anisotropy has been completely decoupled from the r value by using non associated flow plasticity, where yield function and plastic potential have been treated separately to take care of stress and r value directionalities, respectively. This theoretical development has been verified using Zr alloys at room temperature as an example as these materials have very strong SD (Strength Differential) effect. The proposed yield function reasonably well models the evolution of yield surfaces for a zirconium clock rolled plate during in plane and through thickness compression. It has been found that this function can predict both tension and compression asymmetry mathematically without any numerical tolerance and shows the significant improvement compared to any reported functions. Finally, in the end of the report, a program of further research is outlined aimed at constructing tensorial relationships for the temperature and fluence dependent creep surfaces for Zr, Zircaloy 2, and Zircaloy 4.

  8. On the multidimensional modeling of fluid flow and heat transfer in SCWRS

    SciTech Connect (OSTI)

    Gallaway, T.; Antal, S. P.; Podowski, M. Z.

    2012-07-01

    The Supercritical Water Reactor (SCWR) has been proposed as one of the six Generation IV reactor design concepts under consideration. The key feature of the SCWR is that water at supercritical pressures is used as the reactor coolant. Although at such pressures, fluids do not undergo phase change as they are heated, the fluid properties experience dramatic variations throughout what is known as the pseudo-critical region. Highly nonuniform temperature and fluid property distributions are expected in the reactor core, which will have a significant impact on turbulence and heat transfer in future SCWRs. The goal of the present work has been to understand and predict the effects of these fluid property variations on turbulence and heat transfer throughout the reactor core. Spline-type property models have been formulated for water at supercritical pressures in order to include the dependence of properties on both temperature and pressure into a numerical solver. New models of turbulence and heat transfer for variable-property fluids have been developed and implemented into the NPHASE-CMFD software. The results for these models have been compared to experimental data from the Korea Atomic Energy Research Inst. (KAERI) for various heat transfer regimes. It is found that the Low-Reynolds {kappa}-{epsilon} model performs best at predicting the experimental data. (authors)

  9. Groundwater Update K. Michael Thompson Soil and Groundwater Division Richland Operations Office

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Update Jon Peschong Richland Operations Office May 2015 2 billion gallons of contaminated groundwater treated tons of contaminants removed in all pump and treat systems since the facilities began operating 12 171 HANFORD SITE GROUNDWATER NUMBERS billion of gallons of groundwater treated in 2014 1.95 tons of contaminants removed in 2014 62 3 Groundwater Key Focus Areas * Expand pump and treat systems - Continue pump and treat operations - Install and connect new and existing wells to maximize

  10. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect (OSTI)

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2010-09-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

  11. Building Conceptual Models of Field-Scale Uranium Reactive Transport in a Dynamic Vadose Zone-Aquifer-River System

    SciTech Connect (OSTI)

    Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.

    2008-12-04

    Subsurface simulation is being used to build, test, and couple conceptual process models to better understand controls on a 0.4 km by 1.0 km uranium plume that has persisted above the drinking water standard in the groundwater of the Hanford 300 Area over the last 15 years. At this site, uranium-contaminated sediments in the vadose zone and aquifer are subject to significant variations in water levels and velocities driven by the diurnal, weekly, seasonal, and episodic Columbia River stage dynamics. Groundwater flow reversals typically occur twice a day with significant exchange of river water and groundwater in the near-river aquifer. Mixing of the dilute solution chemistry of the river with the groundwater complicates the uranium sorption behavior as the mobility of U(VI) has been shown experimentally to be a function of pH, carbonate, calcium, and uranium. Furthermore, uranium mass transfer between solid and aqueous phases has been observed to be rate-limited in the context of the high groundwater velocities resulting from the river stage fluctuations and the highly transmissive sediments (hydraulic conductivities ~1500 m/d). One- and two-dimensional vertical cross-sectional simulations of variably-saturated flow and reactive transport, based on laboratory-derived models of distributed rate mass transfer and equilibrium multicomponent surface complexation, are used to assess uranium transport at the dynamic vadose zone aquifer interface as well as changes to uranium mobility due to incursions of river water into the aquifer.

  12. Groundwater Withdrawal Permit Application | Open Energy Information

    Open Energy Info (EERE)

    Withdrawal Permit ApplicationLegal Abstract This application initiates the Drinking Water and Groundwater Protection Division's, a division of the Department of Environmental...

  13. DEQ Groundwater Permitting Guidebook | Open Energy Information

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance - GuideHandbook: DEQ Groundwater Permitting GuidebookPermittingRegulatory GuidanceGuide...

  14. Compendium of ordinances for groundwater protection

    SciTech Connect (OSTI)

    Not Available

    1990-08-01

    Groundwater is an extremely important resource in the Tennessee Valley. Nearly two-thirds of the Tennessee Valley's residents rely, at least in part, on groundwater supplies for drinking water. In rural areas, approximately ninety-five percent of residents rely on groundwater for domestic supplies. Population growth and economic development increase the volume and kinds of wastes requiring disposal which can lead to groundwater contamination. In addition to disposal which can lead to groundwater contamination. In addition to disposal problems associated with increases in conventional wastewater and solid waste, technological advancements in recent decades have resulted in new chemicals and increased usage in agriculture, industry, and the home. Unfortunately, there has not been comparable progress in identifying the potential long-term effects of these chemicals, in managing them to prevent contamination of groundwater, or in developing treatment technologies for removing them from water once contamination has occurred. The challenge facing residence of the Tennessee Valley is to manage growth and economic and technological development in ways that will avoid polluting the groundwater resource. Once groundwater has been contaminated, cleanup is almost always very costly and is sometimes impractical or technically infeasible. Therefore, prevention of contamination -- not remedial treatment--is the key to continued availability of usable groundwater. This document discusses regulations to aid in this prevention.

  15. Montana Groundwater Information Center Webpage | Open Energy...

    Open Energy Info (EERE)

    Center Webpage Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Montana Groundwater Information Center Webpage Abstract Provides access to...

  16. Vermont Groundwater Withdrawal Report | Open Energy Information

    Open Energy Info (EERE)

    Not Provided DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Vermont Groundwater Withdrawal Report Citation Vermont Agency of Natural...

  17. Hanford Treats Record Amount of Groundwater

    Broader source: Energy.gov [DOE]

    Workers have treated more than 800 million gallons of groundwater at the Hanford Site so far this year, a record annual amount.

  18. Evapotranspiration Dynamics and Effects on Groundwater Recharge...

    Office of Scientific and Technical Information (OSTI)

    Vegetation type and health had a significant effect on the site water balance. Plant cover ... Heavy grazing increased groundwater recharge (PPT > ET over the 13-year period). ...

  19. A summary of methods for approximating salt creep and disposal room closure in numerical models of multiphase flow

    SciTech Connect (OSTI)

    Freeze, G.A.; Larson, K.W.; Davies, P.B.

    1995-10-01

    Eight alternative methods for approximating salt creep and disposal room closure in a multiphase flow model of the Waste Isolation Pilot Plant (WIPP) were implemented and evaluated: Three fixed-room geometries three porosity functions and two fluid-phase-salt methods. The pressure-time-porosity line interpolation method is the method used in current WIPP Performance Assessment calculations. The room closure approximation methods were calibrated against a series of room closure simulations performed using a creep closure code, SANCHO. The fixed-room geometries did not incorporate a direct coupling between room void volume and room pressure. The two porosity function methods that utilized moles of gas as an independent parameter for closure coupling. The capillary backstress method was unable to accurately simulate conditions of re-closure of the room. Two methods were found to be accurate enough to approximate the effects of room closure; the boundary backstress method and pressure-time-porosity line interpolation. The boundary backstress method is a more reliable indicator of system behavior due to a theoretical basis for modeling salt deformation as a viscous process. It is a complex method and a detailed calibration process is required. The pressure lines method is thought to be less reliable because the results were skewed towards SANCHO results in simulations where the sequence of gas generation was significantly different from the SANCHO gas-generation rate histories used for closure calibration. This limitation in the pressure lines method is most pronounced at higher gas-generation rates and is relatively insignificant at lower gas-generation rates. Due to its relative simplicity, the pressure lines method is easier to implement in multiphase flow codes and simulations have a shorter execution time.

  20. Final Report: A Model Management System for Numerical Simulations of Subsurface Processes

    SciTech Connect (OSTI)

    Zachmann, David

    2013-10-07

    The DOE and several other Federal agencies have committed significant resources to support the development of a large number of mathematical models for studying subsurface science problems such as groundwater flow, fate of contaminants and carbon sequestration, to mention only a few. This project provides new tools to help decision makers and stakeholders in subsurface science related problems to select an appropriate set of simulation models for a given field application.

  1. Idaho National Laboratory Experimental Program to Measure the Flow Phenomena in a Scaled Model of a Prismatic Gas-Cooled Reactor Lower Plenum for Validation of CFD Codes

    SciTech Connect (OSTI)

    Hugh M. McIlroy Jr.; Donald M. McEligot; Robert J. Pink

    2008-09-01

    The experimental program that is being conducted at the Matched Index-of-Refraction (MIR) Flow Facility at Idaho National Laboratory (INL) to obtain benchmark data on measurements of flow phenomena in a scaled model of a prismatic gas-cooled reactor lower plenum using 3-D Particle Image Velocimetry (PIV) is presented. A description of the scaling analysis, experimental facility, 3-D PIV system, measurement uncertainties and analysis, experimental procedures and samples of the data sets that have been obtained are included. Samples of the data set that will be presented include mean-velocity-field and turbulence data in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid. The benefit of the MIR technique is that it permits high-quality measurements to be obtained without locating intrusive transducers that disturb the flow field and without distortion of the optical paths. An advantage of the INL MIR system is its large size which allows improved spatial and temporal resolution compared to similar facilities at smaller scales. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. The measurements

  2. TECHNICAL EVALUATION OF TEMPORAL GROUNDWATER MONITORING VARIABILITY IN MW66 AND NEARBY WELLS, PADUCAH GASEOUS DIFFUSION PLANT

    SciTech Connect (OSTI)

    Looney, B.; Eddy-Dilek, C.

    2012-08-28

    Evaluation of disposal records, soil data, and spatial/temporal groundwater data from the Paducah Gaseous Diffusion Plant (PGDP) Solid Waste Management Unit (SWMU) 7 indicate that the peak contaminant concentrations measured in monitoring well (MW) 66 result from the influence of the regional PGDP NW Plume, and does not support the presence of significant vertical transport from local contaminant sources in SWMU 7. This updated evaluation supports the 2006 conceptualization which suggested the high and low concentrations in MW66 represent different flow conditions (i.e., local versus regional influences). Incorporation of the additional lines of evidence from data collected since 2006 provide the basis to link high contaminant concentrations in MW66 (peaks) to the regional 'Northwest Plume' and to the upgradient source, specifically, the C400 Building Area. The conceptual model was further refined to demonstrate that groundwater and the various contaminant plumes respond to complex site conditions in predictable ways. This type of conceptualization bounds the expected system behavior and supports development of environmental cleanup strategies, providing a basis to support decisions even if it is not feasible to completely characterize all of the 'complexities' present in the system. We recommend that the site carefully consider the potential impacts to groundwater and contaminant plume migration as they plan and implement onsite production operations, remediation efforts, and reconfiguration activities. For example, this conceptual model suggests that rerouting drainage water, constructing ponds or basin, reconfiguring cooling water systems, capping sites, decommissioning buildings, fixing (or not fixing) water leaks, and other similar actions will potentially have a 'direct' impact on the groundwater contaminant plumes. Our conclusion that the peak concentrations in MW66 are linked to the regional PGDP NW Plume does not imply that there TCE is not present in SWMU

  3. Hanford Site Groundwater Monitoring for Fiscal Year 1999

    SciTech Connect (OSTI)

    MJ Hartman; LF Morasch; WD Webber

    2000-05-10

    This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 1999 on the US. Department of Energy's Hanford Site, Washington. Water-level monitoring was performed to evaluate groundwater flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Measurements for site-wide maps were conducted in June in past years and are now measured in March to reflect conditions that are closer to average. Water levels over most of the Hanford Site continued to decline between June 1998 and March 1999. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of carbon-14, strontium-90, technetium-99, and uranium also exceeded drinking water standards in smaller plumes. Cesium-137 and plutonium exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in US Department of Energy Order 5400.5 were exceeded for plutonium, strontium-90, tritium, and uranium in small plumes or single wells. Nitrate and carbon tetrachloride are the most extensive chemical contaminants. Chloroform, chromium, cis-1,2dichloroethylene, cyanide, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels in filtered samples from numerous wells; however, in most cases, they are believed to represent natural components of groundwater. ''Resource Conservation and Recovery Act of 1976'' groundwater monitoring continued at 25 waste management areas during fiscal year 1999: 16 under detection programs and data indicate that they are not adversely affecting groundwater; 6 under interim status groundwater quality assessment programs to assess contamination; and 2 under final status corrective-action programs. Another site, the 120-D-1 ponds, was clean closed in

  4. The Soils and Groundwater – EM-20 S&T Roadmap Quality Assurance Project Plan

    SciTech Connect (OSTI)

    Fix, N. J.

    2008-02-11

    The Soils and Groundwater – EM-20 Science and Technology Roadmap Project is a U.S. Department of Energy, Office of Environmental Management-funded initiative designed to develop new methods, strategies and technology for characterizing, modeling, remediating, and monitoring soils and groundwater contaminated with metals, radionuclides, and chlorinated organics. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by EM-20 Roadmap Project staff.

  5. Monte Carlo modeling of electron density in hypersonic rarefied gas flows

    SciTech Connect (OSTI)

    Fan, Jin; Zhang, Yuhuai; Jiang, Jianzheng

    2014-12-09

    The electron density distribution around a vehicle employed in the RAM-C II flight test is calculated with the DSMC method. To resolve the mole fraction of electrons which is several orders lower than those of the primary species in the free stream, an algorithm named as trace species separation (TSS) is utilized. The TSS algorithm solves the primary and trace species separately, which is similar to the DSMC overlay techniques; however it generates new simulated molecules of trace species, such as ions and electrons in each cell, basing on the ionization and recombination rates directly, which differs from the DSMC overlay techniques based on probabilistic models. The electron density distributions computed by TSS agree well with the flight data measured in the RAM-C II test along a decent trajectory at three altitudes 81km, 76km, and 71km.

  6. Community College Highlights Paducah Site Groundwater Model ...

    Broader source: Energy.gov (indexed) [DOE]

    Barbara Veazey, Paducah Junior College Board of Trustees member Ken Wheeler and Buz Smith ... Barbara Veazey, Paducah Junior College Board of Trustees member Ken Wheeler and Buz Smith ...

  7. An Evaluation of Mesoscale Model Predictions of Down-Valley and Canyon Flows and Their Consequences Using Doppler Lidar Measurements During VTMX 2000

    SciTech Connect (OSTI)

    Fast, Jerome D.; Darby, Lisa S.

    2004-04-01

    A mesoscale model, a Lagrangian particle dispersion model, and extensive Doppler lidar wind measurements during the VTMX 2000 field campaign were used to examine converging flows over the Salt Lake Valley and their effect on vertical mixing of tracers at night and during the morning transition period. The simulated wind components were transformed into radial velocities to make a direct comparison with about 1.3 million Doppler lidar data points and critically evaluate, using correlation coefficients, the spatial variations in the simulated wind fields aloft. The mesoscale model captured reasonably well the general features of the observed circulations including the daytime up-valley flow, the nighttime slope, canyon, and down-valley flows, and the convergence of the flows over the valley. When there were errors in the simulated wind fields, they were usually associated with the timing, structure, or strength of specific flows. Simulated outflows from canyons along the Wasatch Mountains propagated over the valley and converged with the down-valley flow, but the advance and retreat of these simulated flows was often out of phase with the lidar measurements. While the flow reversal during the evening transition period produced rising motions over much of the valley atmosphere in the absence of significant ambient winds, average vertical velocities became close to zero as the down-valley flow developed. Still, vertical velocities between 5 and 15 cm s-1 occurred where down-slope, canyon and down-valley flows converged and vertical velocities greater than 50 cm s-1 were produced by hydraulic jumps at the base of the canyons. The presence of strong ambient winds resulted in smaller average rising motions during the evening transition period and larger average vertical velocities after that. A fraction of the tracer released at the surface was transported up to the height of the surrounding mountains; however, higher concentrations were produced aloft for evenings

  8. A validation of the [sup 3]H/[sup 3]He method for determining groundwater recharge

    SciTech Connect (OSTI)

    Solomon, D.K. ); Schiff, S.L. ); Poreda, R.J. ); Clarke, W.B. )

    1993-09-01

    Tritium and He isotopes have been measured at a site where groundwater flow is nearly vertical for a travel time of 100 years and where recharge rates are spatially variable. Because the mid-1960s [sup 3]H peak (arising from aboveground testing of thermonuclear devices) is well-defined, the vertical groundwater velocity is known with unusual accuracy at this site. Utilizing [sup 3]H and its stable daughter [sup 3]He to determine groundwater ages, we compute a recharge rate of 0.16 m/yr, which agrees to within about 5% of the value based on the depth of the [sup 3]H peak (measured both in 1986 and 1991) and two-dimensional modeling in an area of high recharge. Zero [sup 3]H/[sup 3]He age occurs at a depth that is approximately equal to the average depth of the annual low water table, even though the capillary fringe extends to land surface during most of the year at the study site. In an area of low recharge (0.05 m/yr) where the [sup 3]H peak (and hence the vertical velocity) is also well-defined, the [sup 3]H/[sup 3]He results could not be used to compute recharge because samples were not collected sufficiently far above the [sup 3]H peak; however, modeling indicates that the [sup 3]H/[sup 3]He age gradient near the water table is an accurate measure of vertical velocities in the low-recharge area. Because [sup 3]H and [sup 3]He have different diffusion coefficients, and because the amount of mechanical mixing is different in the area of high recharge than in the low-recharge area, we have separated the dispersive effects of mechanical mixing from molecular diffusion. We estimate a longitudinal dispersivity of 0.07 m and effective diffusion coefficients for [sup 3]H ([sup 3]HHO) and [sup 3]He of 2.4 x 10[sup [minus]5] and 1.3 x 10[sup [minus]4] m[sup 2]/day, respectively. 26 refs., 8 figs., 1 tab.

  9. Extraction of diffuse correlation spectroscopy flow index by integration of Nth-order linear model with Monte Carlo simulation

    SciTech Connect (OSTI)

    Shang, Yu; Lin, Yu; Yu, Guoqiang; Li, Ting; Chen, Lei; Toborek, Michal

    2014-05-12

    Conventional semi-infinite solution for extracting blood flow index (BFI) from diffuse correlation spectroscopy (DCS) measurements may cause errors in estimation of BFI (αD{sub B}) in tissues with small volume and large curvature. We proposed an algorithm integrating Nth-order linear model of autocorrelation function with the Monte Carlo simulation of photon migrations in tissue for the extraction of αD{sub B}. The volume and geometry of the measured tissue were incorporated in the Monte Carlo simulation, which overcome the semi-infinite restrictions. The algorithm was tested using computer simulations on four tissue models with varied volumes/geometries and applied on an in vivo stroke model of mouse. Computer simulations shows that the high-order (N ≥ 5) linear algorithm was more accurate in extracting αD{sub B} (errors < ±2%) from the noise-free DCS data than the semi-infinite solution (errors: −5.3% to −18.0%) for different tissue models. Although adding random noises to DCS data resulted in αD{sub B} variations, the mean values of errors in extracting αD{sub B} were similar to those reconstructed from the noise-free DCS data. In addition, the errors in extracting the relative changes of αD{sub B} using both linear algorithm and semi-infinite solution were fairly small (errors < ±2.0%) and did not rely on the tissue volume/geometry. The experimental results from the in vivo stroke mice agreed with those in simulations, demonstrating the robustness of the linear algorithm. DCS with the high-order linear algorithm shows the potential for the inter-subject comparison and longitudinal monitoring of absolute BFI in a variety of tissues/organs with different volumes/geometries.

  10. Portsmouth Gaseous Diffusion Plant- Quadrant I Groundwater Investigative (5-Unit) Area Plume

    Broader source: Energy.gov [DOE]

    Groundwater Database Report - Portsmouth Gaseous Diffusion Plant - Quadrant I Groundwater Investigative (5-Unit) Area Plume

  11. Modelling of the Arc-Jet Plasma Flow in the SR5 Nozzle Using a Thermochemical Nonequilibrium and a State-to-State Approach

    SciTech Connect (OSTI)

    Lino da Silva, M.; Passarinho, F.; Alexandrova, T.; Dudeck, M.

    2005-05-16

    A numerical code has been set-up for estimating the relative importance of the different nonequilibrium physical-chemical processes in the SR5 facility arc-jet plasma generator. The code assumes a quasi-1D description of the flow in the plasma generator convergent-divergent nozzle, allowing the modelling of a large array of processes at low computational cost. The center streamline of the flow is simulated in the nozzle throat where arc energy input is treated as a constant energy input. This center streamline is not assumed to be affected by nozzle walls cooling in the diverging section. Chemical, V-T, V-V, V-D and R-T processes are taken into account for CO2-N2 and N2-O2 flows. The results for a CO2-N2 flow show that rotational equilibrium and near vibrational equilibrium are reached in the nozzle throat, and that the sudden expansion in the diverging section leads to a freezing of chemical compositions and vibrational temperatures, and also rotational nonequilibrium. Only chemical processes are found to affect sensibly the flow macroscopic parameters. Finally a comparison with a state-to-state model for an N2-O2 flow in the diverging section proved that some differences between the vibrational temperatures could be expected due to non-Boltzmann vibrational levels distributions. This is particularly true for the O2 first vibrational temperature.

  12. Recovery Act Supports Construction of Site's Largest Groundwater...

    Office of Environmental Management (EM)

    Supports Construction of Site's Largest Groundwater Treatment Facility Recovery Act Supports Construction of Site's Largest Groundwater Treatment Facility Construction of the ...

  13. Passive Groundwater Cleanup Measures Save Savannah River Site...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Passive Groundwater Cleanup Measures Save Savannah River Site Millions of Dollars Passive Groundwater Cleanup Measures Save Savannah River Site Millions of Dollars November 25, ...

  14. Savannah River Site - L-Area Southern Groundwater | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    L-Area Southern Groundwater Savannah River Site - L-Area Southern Groundwater January 1, ... InstallationName, State: Savannah River Site, SC Responsible DOE Office: Savannah River ...

  15. Savannah River Site - R-Area Groundwater Operable Unit | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    R-Area Groundwater Operable Unit Savannah River Site - R-Area Groundwater Operable Unit ... InstallationName, State: Savannah River Site, SC Responsible DOE Office: Savannah River ...

  16. South Valley Archived Soil & Groundwater Master Reports | Department...

    Broader source: Energy.gov (indexed) [DOE]

    South Valley Archived Soil & Groundwater Master Reports South Valley - South Valley Plume (16.5 KB) More Documents & Publications Slick Rock Archived Soil & Groundwater Master ...

  17. Rocky Flats Environmental Technology Site Archived Soil & Groundwater...

    Office of Environmental Management (EM)

    Rocky Flats Environmental Technology Site Archived Soil & Groundwater Master Reports Rocky Flats Environmental Technology Site Archived Soil & Groundwater Master Reports Rocky ...

  18. New Resin Brings Efficiencies to Groundwater Treatment along...

    Broader source: Energy.gov (indexed) [DOE]

    A new treatment material is expected to increase groundwater treatment efficiency and ... A new treatment material is expected to increase groundwater treatment efficiency and ...

  19. Recommendation 222: Recommendations on Additional Off-site Groundwater...

    Office of Environmental Management (EM)

    2: Recommendations on Additional Off-site Groundwater Migration Studies Recommendation 222: Recommendations on Additional Off-site Groundwater Migration Studies ORSSAB recommends...

  20. Rocky Flats Site Expands Solar Power for Treating Groundwater...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rocky Flats Site Expands Solar Power for Treating Groundwater Rocky Flats Site Expands Solar Power for Treating Groundwater April 17, 2013 - 1:26pm Addthis Subcontractor personnel ...