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1

Modeling of concentrated aqueous solutions: Efficient implementation of Pitzer equations in geochemical and reactive transport models  

Science Conference Proceedings (OSTI)

Modeling concentrated solutions demands the use of ion-interaction models such as Pitzer equations, which involve a large number of operations. Implementation of these models in large reactive transport simulations significantly increases the computation ... Keywords: Concentrated solutions, Evaporation of seawater, Geochemical modeling, HMW model, Invariant points, Object-oriented programming, Pitzer, Reactive transport modeling

S. A. Bea; J. Carrera; C. Ayora; F. Batlle

2010-04-01T23:59:59.000Z

2

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) reactive fluid flow and transport in fractured rocks as well as porous

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-01-01T23:59:59.000Z

3

TOUGHREACT-A simulation program for non-isothermal multiphase reactive geochemical transport in variably saturated geologic media: Applications to geothermal injectivity and CO2 geological sequestration  

Science Conference Proceedings (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase ... Keywords: CO2 geologic sequestration, Clay swelling, Geochemical transport, Hydrothermal systems, Injectivity enhancement, Mineral scaling, Mineral trapping, Reactive fluid flow, Saline aquifer, TOUGHREACT

Tianfu Xu; Eric Sonnenthal; Nicolas Spycher; Karsten Pruess

2006-03-01T23:59:59.000Z

4

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variable Saturated Geologic Media  

DOE Green Energy (OSTI)

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport and chemical reactions can be used for the assessment of mineral alteration in hydrothermal systems, waste disposal sites, acid mine drainage remediation, contaminant transport, and groundwater quality. A comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator, TOUGHREACT, has been developed. A wide range of subsurface thermo-physical-chemical processes is considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. The program can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The model can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can proceed either subject to local equilibrium or kinetic conditions. Changes in porosity and permeability due to mineral dissolution and precipitation can be considered. Linear adsorption and decay can be included. For the purpose of future extensions, surface complexation by double layer model is coded in the program. Xu and Pruess (1998) developed a first version of a non-isothermal reactive geochemical transport model, TOUGHREACT, by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). Xu, Pruess, and their colleagues have applied the program to a variety of problems such as: (1) supergene copper enrichment (Xu et al, 2001), (2) caprock mineral alteration in a hydrothermal system (Xu and Pruess, 2001a), and (3) mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al, 2003b and 2004a). For modeling the coupled thermal, hydrological, and chemical processes during heater tests at proposed nuclear waste disposal site at Yucca Mountain (Nevada), Sonnenthal and Spycher (2000) and Spycher et al. (2003) enhanced TOUGHREACT on (1) high temperature geochemistry, (2) mineral reactive surface area calculations, and (3) porosity and permeability changes due to mineral alteration. On the other hand, Pruess et al. (1999) updated the TOUGH2 simulator to TOUGH2 V2. The present version of TOUGHREACT was developed by introducing the work of Sonnenthal and Spycher (2000) to the original work of Xu and Pruess (1998), and by replacing TOUGH2 (Pruess, 1991) by TOUGH2 V2 (Pruess et al, 1999). The TOUGHREACT program makes use of ''self-documenting'' features. It is distributed with a number of input data files for sample problems. Besides providing benchmarks for proper code installation, these can serve as self-teaching tutorial in the use of TOUGHREACT, and they provide templates to help jump-start new applications. The fluid and heat flow part of TOUGHREACT is derived from TOUGH2 V2, so in addition to the current manual, users must have manual of the TOUGH2 V2 (Pruess et al., 1999). The present version of TOUGHREACT provides the following different TOUGH2 fluid property or ''EOS'' (equation-of-state) modules: (1) EOS1 for water, or two waters with typical applications to hydrothermal problems, (2) EOS2 for multiphase mixtures of water and CO{sub 2} also with typical applications to hydrothermal problems, (3) EOS3 for multiphase mixtures of water and air with typical applications to vadose zone and nuclear waste disposal problems, (4) EOS4 that has the same capabilities as EOS3 but with vapor pressure lowering effects due to capillary pressure, (5) EOS9 for single phase water (Richards. equation) with typical applications to ambient reactive geochemical transport problems, (6) ECO2 for multiphase mixtures of water, CO{sub 2} and NaCl with typical applications to CO{sub 2} disposal in deep brine aquifers.

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-05-24T23:59:59.000Z

5

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

DOE Green Energy (OSTI)

The interaction between hydrothermal fluids and the rocks through which they migrate alters the earlier formed primary minerals and leads to the formation of secondary minerals, resulting in changes in the physical and chemical properties of the system. We have developed a comprehensive numerical simulator, TOUGHREACT, which considers nonisothermal multi-component chemical transport in both liquid and gas phases. A variety of subsurface thermo-physical-chemical processes is considered under a wide range of conditions of pressure, temperature, water saturation, and ionic strength. The code can be applied to problems in fundamental analysis of the hydrothermal systems and in the exploration of geothermal reservoirs including chemical evolution, mineral alteration, mineral scaling, changes of porosity and permeability, and mineral recovery from geothermal fluids.

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-07-31T23:59:59.000Z

6

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1  

Science Conference Proceedings (OSTI)

Coupled modeling of subsurface multiphase fluid and heat flow, solute transport, and chemical reactions can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. TOUGHREACT has been developed as a comprehensive non-isothermal multi-component reactive fluid flow and geochemical transport simulator to investigate these and other problems. A number of subsurface thermo-physical-chemical processes are considered under various thermohydrological and geochemical conditions of pressure, temperature, water saturation, and ionic strength. TOUGHREACT can be applied to one-, two- or three-dimensional porous and fractured media with physical and chemical heterogeneity. The code can accommodate any number of chemical species present in liquid, gas and solid phases. A variety of equilibrium chemical reactions are considered, such as aqueous complexation, gas dissolution/exsolution, and cation exchange. Mineral dissolution/precipitation can take place subject to either local equilibrium or kinetic controls, with coupling to changes in porosity and permeability and capillary pressure in unsaturated systems. Chemical components can also be treated by linear adsorption and radioactive decay. The first version of the non-isothermal reactive geochemical transport code TOUGHREACT was developed (Xu and Pruess, 1998) by introducing reactive geochemistry into the framework of the existing multi-phase fluid and heat flow code TOUGH2 (Pruess, 1991). TOUGHREACT was further enhanced with the addition of (1) treatment of mineral-water-gas reactive-transport under boiling conditions, (2) an improved HKF activity model for aqueous species, (3) gas species diffusion coefficients calculated as a function of pressure, temperature, and molecular properties, (4) mineral reactive surface area formulations for fractured and porous media, and (5) porosity, permeability, and capillary pressure changes owing to mineral precipitation/dissolution (Sonnenthal et al., 1998, 2000, 2001; Spycher et al., 2003a). Subsequently, TOUGH2 V2 was released with additional EOS modules and features (Pruess et al., 1999). The present version of TOUGHREACT includes all of the previous extensions to the original version, along with the replacement of the original TOUGH2 (Pruess, 1991) by TOUGH2 V2 (Pruess et al., 1999). TOUGHREACT has been applied to a wide variety of problems, some of which are included as examples, such as: (1) Supergene copper enrichment (Xu et al., 2001); (2) Mineral alteration in hydrothermal systems (Xu and Pruess, 2001a; Xu et al., 2004b; Dobson et al., 2004); (3) Mineral trapping for CO{sub 2} disposal in deep saline aquifers (Xu et al., 2003b and 2004a); (4) Coupled thermal, hydrological, and chemical processes in boiling unsaturated tuff for the proposed nuclear waste emplacement site at Yucca Mountain, Nevada (Sonnenthal et al., 1998, 2001; Sonnenthal and Spycher, 2000; Spycher et al., 2003a, b; Xu et al., 2001); (5) Modeling of mineral precipitation/dissolution in plug-flow and fracture-flow experiments under boiling conditions (Dobson et al., 2003); (6) Calcite precipitation in the vadose zone as a function of net infiltration (Xu et al., 2003); and (7) Stable isotope fractionation in unsaturated zone pore water and vapor (Singleton et al., 2004). The TOUGHREACT program makes use of 'self-documenting' features. It is distributed with a number of input data files for sample problems. Besides providing benchmarks for proper code installation, these can serve as a self-teaching tutorial in the use of TOUGHREACT, and they provide templates to help jump-start new applications. The fluid and heat flow part of TOUGHREACT is derived from TOUGH2 V2, so in addition to the current manual, users must have the manual of the TOUGH2 V2 (Pruess et al., 1999). The present version of TOUGHREACT provides the following TOUGH2 fluid property or 'EOS' (equation-of-state) modules: (1) EOS1 for

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2008-09-29T23:59:59.000Z

7

TOURGHREACT: A Simulation Program for Non-isothermal MultiphaseReactive Geochemical Transport in Variably Saturated GeologicMedia  

DOE Green Energy (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media. The program was written in Fortran 77 and developed by introducing reactive geochemistry into the multiphase fluid and heat flow simulator TOUGH2. A variety of subsurface thermo-physical-chemical processes are considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, and pH and Eh. Interactions between mineral assemblages and fluids can occur under local equilibrium or kinetic rates. The gas phase can be chemically active. Precipitation and dissolution reactions can change formation porosity and permeability. The program can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, acid mine drainage remediation, contaminant transport, and groundwater quality. Here we present two examples to illustrate applicability of the program: (1) injectivity effects of mineral scaling in a fractured geothermal reservoir and (2) CO2 disposal in a deep saline aquifer.

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-12-07T23:59:59.000Z

8

TOUGHREACT: a new code of the TOUGH Family for Non-Isothermal multiphase reactive geochemical transport in variably saturated geologic media  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) we consider not only porous

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-01-01T23:59:59.000Z

9

Benchmarking a Visual-Basic based multi-component one-dimensional reactive transport modeling tool  

Science Conference Proceedings (OSTI)

We present the details of a comprehensive numerical modeling tool, RT1D, which can be used for simulating biochemical and geochemical reactive transport problems. The code can be run within the standard Microsoft EXCEL Visual Basic platform, and it does ... Keywords: Bioremediation, Geochemical transport, Groundwater models, Numerical model, Reactive transport

Jagadish Torlapati; T. Prabhakar Clement

2013-01-01T23:59:59.000Z

10

Developing a robust geochemical and reactive transport model to evaluate possible sources of arsenic at the CO2 sequestration natural analog site in Chimayo, New Mexico  

SciTech Connect

Migration of carbon dioxide (CO2) from deep storage formations into shallow drinking water aquifers is a possible system failure related to geologic CO2 sequestration. A CO2 leak may cause mineral precipitation/ dissolution reactions, changes in aqueous speciation, and alteration of pH and redox conditions leading to potential increases of trace metal concentrations above EPA National Primary Drinking Water Standards. In this study, the Chimayo site (NM) was examined for site-specific impacts of shallow groundwater interacting with CO2 from deep storage formations. Major ion and trace element chemistry for the site have been previously studied. This work focuses on arsenic (As), which is regulated by the EPA under the Safe Drinking Water Act and for which some wells in the Chimayo area have concentrations higher than the maximum contaminant level (MCL). Statistical analysis of the existing Chimayo groundwater data indicates that As is strongly correlated with trace metals U and Pb indicating that their source may be from the same deep subsurface water. Batch experiments and materials characterization, such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), and synchrotron micro X-ray fluorescence (#2;-XRF), were used to identify As association with Fe-rich phases, such as clays or oxides, in the Chimayo sediments as the major factor controlling As fate in the subsurface. Batch laboratory experiments with Chimayo sediments and groundwater show that pH decreases as CO2 is introduced into the system and buffered by calcite. The introduction of CO2 causes an immediate increase in As solution concentration, which then decreases over time. A geochemical model was developed to simulate these batch experiments and successfully predicted the pH drop once CO2 was introduced into the experiment. In the model, sorption of As to illite, kaolinite and smectite through surface complexation proved to be the key reactions in simulating the drop in As concentration as a function of time in the batch experiments. Based on modeling, kaolinite precipitation is anticipated to occur during the experiment, which allows for additional sorption sites to form with time resulting in the slow decrease in As concentration. This mechanism can be viewed as trace metal “scavenging” due to sorption caused secondary mineral precipitation. Since deep geologic transport of these trace metals to the shallow subsurface by brine or CO2 intrusion is critical to assessing environmental impacts, the effective retardation of trace metal transport is an important parameter to estimate and it is dependent on multiple coupled reactions. At the field scale, As mobility is retarded due to the influence of sorption reactions, which can affect environmental performance assessment studies of a sequestration site.

Viswanathana, Hari; Daia, Zhenxue; Lopano, Christina; Keating, Elizabeth; Hakala, J. Alexandra; Scheckelc, Kirk G; Zhengd, Liange; Guthrie, George D.; Pawara, Rajesh

2012-01-01T23:59:59.000Z

11

Developing a robust geochemical and reactive transport model to evaluate possible sources of arsenic at the CO[subscript 2] sequestration natural analog site in Chimayo, New Mexico  

Science Conference Proceedings (OSTI)

Migration of carbon dioxide (CO{sub 2}) from deep storage formations into shallow drinking water aquifers is a possible system failure related to geologic CO{sub 2} sequestration. A CO{sub 2} leak may cause mineral precipitation/dissolution reactions, changes in aqueous speciation, and alteration of pH and redox conditions leading to potential increases of trace metal concentrations above EPA National Primary Drinking Water Standards. In this study, the Chimayo site (NM) was examined for site-specific impacts of shallow groundwater interacting with CO{sub 2} from deep storage formations. Major ion and trace element chemistry for the site have been previously studied. This work focuses on arsenic (As), which is regulated by the EPA under the Safe Drinking Water Act and for which some wells in the Chimayo area have concentrations higher than the maximum contaminant level (MCL). Statistical analysis of the existing Chimayo groundwater data indicates that As is strongly correlated with trace metals U and Pb indicating that their source may be from the same deep subsurface water. Batch experiments and materials characterization, such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), and synchrotron micro X-ray fluorescence ({mu}-XRF), were used to identify As association with Fe-rich phases, such as clays or oxides, in the Chimayo sediments as the major factor controlling As fate in the subsurface. Batch laboratory experiments with Chimayo sediments and groundwater show that pH decreases as CO{sub 2} is introduced into the system and buffered by calcite. The introduction of CO{sub 2} causes an immediate increase in As solution concentration, which then decreases over time. A geochemical model was developed to simulate these batch experiments and successfully predicted the pH drop once CO{sub 2} was introduced into the experiment. In the model, sorption of As to illite, kaolinite and smectite through surface complexation proved to be the key reactions in simulating the drop in As concentration as a function of time in the batch experiments. Based on modeling, kaolinite precipitation is anticipated to occur during the experiment, which allows for additional sorption sites to form with time resulting in the slow decrease in As concentration. This mechanism can be viewed as trace metal 'scavenging' due to sorption caused secondary mineral precipitation. Since deep geologic transport of these trace metals to the shallow subsurface by brine or CO{sub 2} intrusion is critical to assessing environmental impacts, the effective retardation of trace metal transport is an important parameter to estimate and it is dependent on multiple coupled reactions. At the field scale, As mobility is retarded due to the influence of sorption reactions, which can affect environmental performance assessment studies of a sequestration site.

Viswanathan, Hari; Dai, Zhenxue; Lopano, Christina; Keating, Elizabeth; Hakala, J. Alexandra; Scheckel, Kirk G.; Zheng, Liange; Gutherie, George D.; Pawar, Rajesh (EPA); (LBNL); (LANL); (NETL)

2012-10-24T23:59:59.000Z

12

Comparison of approaches for simulating reactive solute transport involving organic degradation reactions by multiple terminal electron acceptors  

Science Conference Proceedings (OSTI)

Reactive solute transport models are useful tools for analyzing complex geochemical behavior resulting from biodegradation of organic compounds by multiple terminal electron acceptors (TEAPs). The usual approach of simulating the reactions of multiple ... Keywords: biogeochemistry, groundwater, hydrogen, monod kinetics, thermodynamics

Gary P. Curtis

2003-04-01T23:59:59.000Z

13

Fluid-rock interaction: A reactive transport approach  

SciTech Connect

Fluid-rock interaction (or water-rock interaction, as it was more commonly known) is a subject that has evolved considerably in its scope over the years. Initially its focus was primarily on interactions between subsurface fluids of various temperatures and mostly crystalline rocks, but the scope has broadened now to include fluid interaction with all forms of subsurface materials, whether they are unconsolidated or crystalline ('fluid-solid interaction' is perhaps less euphonious). Disciplines that previously carried their own distinct names, for example, basin diagenesis, early diagenesis, metamorphic petrology, reactive contaminant transport, chemical weathering, are now considered to fall under the broader rubric of fluid-rock interaction, although certainly some of the key research questions differ depending on the environment considered. Beyond the broadening of the environments considered in the study of fluid-rock interaction, the discipline has evolved in perhaps an even more important way. The study of water-rock interaction began by focusing on geochemical interactions in the absence of transport processes, although a few notable exceptions exist (Thompson 1959; Weare et al. 1976). Moreover, these analyses began by adopting a primarily thermodynamic approach, with the implicit or explicit assumption of equilibrium between the fluid and rock. As a result, these early models were fundamentally static rather than dynamic in nature. This all changed with the seminal papers by Helgeson and his co-workers (Helgeson 1968; Helgeson et al. 1969) wherein the concept of an irreversible reaction path was formally introduced into the geochemical literature. In addition to treating the reaction network as a dynamically evolving system, the Helgeson studies introduced an approach that allowed for the consideration of a multicomponent geochemical system, with multiple minerals and species appearing as both reactants and products, at least one of which could be irreversible. Helgeson's pioneering approach was given a more formal kinetic basis (including the introduction of real time rather than reaction progress as the independent variable) in subsequent studies (Lasaga 1981; Aagaard and Helgeson 1982; Lasaga 1984). The reaction path approach can be used to describe chemical processes in a batch or closed system (e.g., a laboratory beaker), but such systems are of limited interest in the Earth sciences where the driving force for most reactions is transport. Lichtner (1988) clarified the application of the reaction path models to water-rock interaction involving transport by demonstrating that they could be used to describe pure advective transport through porous media. By adopting a reference frame which followed the fluid packet as it moved through the medium, the reaction progress variable could be thought of as travel time instead. Multi-component reactive transport models that could treat any combination of transport and biogeochemical processes date back to the early 1980s. Berner and his students applied continuum reactive transport models to describe processes taking place during the early diagenesis of marine sediments (Berner 1980). Lichtner (1985) outlined much of the basic theory for a continuum model for multicomponent reactive transport. Yeh and Tripathi (1989) also presented the theoretical and numerical basis for the treatment of reactive contaminant transport. Steefel and Lasaga (1994) presented a reactive flow and transport model for nonisothermal, kinetically-controlled water-rock interaction and fracture sealing in hydrothermal systems based on simultaneous numerical solution of both reaction and transport This chapter begins with a review of the important transport processes that affect or even control fluid-rock interaction. This is followed by a general introduction to the governing equations for reactive transport, which are broadly applicable to both qualitative and quantitative interpretations of fluid-rock interactions. This framework is expanded through a discussion of specific topics that are the f

Steefel, C.; Maher, K.

2009-04-01T23:59:59.000Z

14

Three-dimensional model for multi-component reactive transport with variable density groundwater flow  

Science Conference Proceedings (OSTI)

PHWAT is a new model that couples a geochemical reaction model (PHREEQC-2) with a density-dependent groundwater flow and solute transport model (SEAWAT) using the split-operator approach. PHWAT was developed to simulate multi-component reactive transport ... Keywords: Cation exchange, Coastal groundwater flow and chemical transport/reaction, Density-dependent flow, MODFLOW, MT3DMS, PHREEQC-2, PHWAT, SEAWAT, Seawater intrusion, Snow-plough effect

X. Mao; H. Prommer; D. A. Barry; C. D. Langevin; B. Panteleit; L. Li

2006-05-01T23:59:59.000Z

15

Multiphase fluid flow and subsequent geochemical transport in variably saturated fractured rocks: 1. Approaches  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) we consider not only porous

Xu, Tianfu; Pruess, Karsten

2000-01-01T23:59:59.000Z

16

Upscaling Reaction Rate Laws In Geochemical Reactive Transport Using Pore-Scale Network Models Dmitri Kavetski1,2,#, Catherine A. Peters1,$, Michael A. Celia1 and Brent Lindquist3  

E-Print Network (OSTI)

, Rutile, Pyrite GY BR Q Pore space Chemical Reactions and Kinetic Rate Laws Primary interest: acid geosequestration studies *aquifer remediation *nuclear waste disposal *other applications Reactive processes occur and examines whether reaction rates applicable at the pore-scale, O(10-100m), are realistic at larger continuum

Peters, Catherine A.

17

STOMP-ECKEChem: An Engineering Perspective on Reactive Transport in Geologic Media  

Science Conference Proceedings (OSTI)

ECKEChem (Equilibrium, Conservation, Kinetic Equation Chemistry) is a reactive transport module for the STOMP suite of multifluid subsurface flow and transport simulators that was developed from an engineering perspective. STOMP comprises a suite of operational modes that are distinguished by the solved coupled conservation equations with capabilities for a variety of subsurface applications (e.g., environmental remediation and stewardship, geologic sequestration of greenhouse gases, gas hydrate production, and oil shale production). The ECKEChem module was designed to provide integrated reactive transport capabilities across the suite of STOMP simulator operational modes. The initial application for the ECKEChem module was in the simulation of the mineralization reactions that occurred with the injection of supercritical carbon dioxide into deep Columbia River basalt formations, where it was implemented in the STOMP-CO2 simulator. The STOMP-ECKEChem solution approach to modeling reactive transport in multifluid geologic media is founded on an engineering perspective: (1) sequential non-iterative coupling between the flow and reactive transport is sufficient, (2) reactive transport can be modeled by operator splitting with local geochemistry and global transport, (3) geochemistry can be expressed as a system of coupled nonlinear equilibrium, conservation and kinetic equations, (4) a limited number of kinetic equation forms are used in geochemical practice. This chapter describes the conceptual approach to converting a geochemical reaction network into a series of equilibrium, conservation and kinetic equations, the implementation of ECKEChem in STOMP, the numerical solution approach, and a demonstration of the simulator on a complex application involving desorption of uranium from contaminated field-textured sediments.

White, Mark D.; Fang, Yilin

2012-04-04T23:59:59.000Z

18

Lattice gas automata for flow and transport in geochemical systems  

Science Conference Proceedings (OSTI)

Lattice gas automata models are described, which couple solute transport with chemical reactions at mineral surfaces within pore networks. Diffusion in a box calculations are illustrated, which compare directly with Fickian diffusion. Chemical reactions at solid surfaces, including precipitation/dissolution, sorption, and catalytic reaction, can be examined with the model because hydrodynamic transport, solute diffusion and mineral surface processes are all treated explicitly. The simplicity and flexibility of the approach provides the ability to study the interrelationship between fluid flow and chemical reactions in porous materials, at a level of complexity that has not previously been computationally possible.

Janecky, D.R.; Chen, S.; Dawson, S.; Eggert, K.C.; Travis, B.J.

1992-01-01T23:59:59.000Z

19

Lattice gas automata for flow and transport in geochemical systems  

Science Conference Proceedings (OSTI)

Lattice gas automata models are described, which couple solute transport with chemical reactions at mineral surfaces within pore networks. Diffusion in a box calculations are illustrated, which compare directly with Fickian diffusion. Chemical reactions at solid surfaces, including precipitation/dissolution, sorption, and catalytic reaction, can be examined with the model because hydrodynamic transport, solute diffusion and mineral surface processes are all treated explicitly. The simplicity and flexibility of the approach provides the ability to study the interrelationship between fluid flow and chemical reactions in porous materials, at a level of complexity that has not previously been computationally possible.

Janecky, D.R.; Chen, S.; Dawson, S.; Eggert, K.C.; Travis, B.J.

1992-05-01T23:59:59.000Z

20

Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation  

SciTech Connect

Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH{sub 4}{sup +} production during urea hydrolysis were incorporated in the model and captured critical changes in the major metal species. The electrical phase increases were potentially due to ion exchange processes that modified charge structure at mineral/water interfaces. Our study revealed the potential of geophysical monitoring for geochemical changes during urea hydrolysis and the advantages of combining multiple approaches to understand complex biogeochemical processes in the subsurface.

Wu, Y.; Ajo-Franklin, J.B.; Spycher, N.; Hubbard, S.S.; Zhang, G.; Williams, K.H.; Taylor, J.; Fujita, Y.; Smith, R.

2011-07-15T23:59:59.000Z

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21

Geophysical Monitoring and Reactive Transport Modeling of Ureolytically-Driven Calcium Carbonate Precipitation  

Science Conference Proceedings (OSTI)

Ureolytically-driven calcium carbonate precipitation is the basis for a promising in-situ remediation method for sequestration of divalent radionuclide and trace metal ions. It has also been proposed for use in geotechnical engineering for soil strengthening applications. Monitoring the occurrence, spatial distribution, and temporal evolution of calcium carbonate precipitation in the subsurface is critical for evaluating the performance of this technology and for developing the predictive models needed for engineering application. In this study, we conducted laboratory column experiments using natural sediment and groundwater to evaluate the utility of geophysical (complex resistivity and seismic) sensing methods, dynamic synchrotron x-ray computed tomography (micro-CT), and reactive transport modeling for tracking ureolytically-driven calcium carbonate precipitation processes under site relevant conditions. Reactive transport modeling with TOUGHREACT successfully simulated the changes of the major chemical components during urea hydrolysis. Even at the relatively low level of urea hydrolysis observed in the experiments, the simulations predicted an enhanced calcium carbonate precipitation rate that was 3-4 times greater than the baseline level. Reactive transport modeling results, geophysical monitoring data and micro-CT imaging correlated well with reaction processes validated by geochemical data. In particular, increases in ionic strength of the pore fluid during urea hydrolysis predicted by geochemical modeling were successfully captured by electrical conductivity measurements and confirmed by geochemical data. The low level of urea hydrolysis and calcium carbonate precipitation suggested by the model and geochemical data was corroborated by minor changes in seismic P-wave velocity measurements and micro-CT imaging; the latter provided direct evidence of sparsely distributed calcium carbonate precipitation. Ion exchange processes promoted through NH4+ production during urea hydrolysis were incorporated in the model and captured critical changes in the major metal species. The electrical phase increases were potentially due to ion exchange processes that modified charge structure at mineral/water interfaces. Our study revealed the potential of geophysical monitoring for geochemical changes during urea hydrolysis and the advantages of combining multiple approaches to understand complex biogeochemical processes in the subsurface.

Yuxin Wu; Jonathan B. Ajo-Franklin; Nicolas Spycher; Susan S. Hubbard; Guoxiang Zhang; Kenneth H. Williams; Joanna Taylor; Yoshiko Fujita; Robert Smith

2011-09-01T23:59:59.000Z

22

Reactive transport modelling of the interaction of fission product ground contamination with alkaline and cementitious leachates  

Science Conference Proceedings (OSTI)

The fission products Cs-137 and Sr-90 are amongst the most common radionuclides occurring in ground contamination at the UK civil nuclear sites. Such contamination is often associated with alkaline liquids and the mobility of these fission products may be affected by these chemical conditions. Similar geochemical effects may also result from cementitious leachate associated with building foundations and the use of grouts to remediate ground contamination. The behaviour of fission products in these scenarios is a complex interaction of hydrogeological and geochemical processes. A suite of modelling tools have been developed to investigate the behaviour of a radioactive plume containing Cs and Sr. Firstly the effects of sorption due to cementitious groundwater is modelled using PHREEQC. This chemical model is then incorporated into PHAST for the 3-D reactive solute transport modeling. Results are presented for a generic scenario including features and processes that are likely to be relevant to a number of civil UK nuclear sites. Initial results show that modelling can be a very cost-effective means to study the complex hydrogeological and geochemical processes involved. Modelling can help predict the mobility of contaminants in a range of site end point scenarios, and in assessing the consequences of decommissioning activities. (authors)

Kwong, S.; Small, J. [Nexia Solutions Ltd, The British Technology Centre, Sellafield, Seascale, CA20 1PG (United Kingdom)

2007-07-01T23:59:59.000Z

23

Transport Modeling of Reactive and Non-Reactive Constituents from Summitville,  

E-Print Network (OSTI)

Survey (USGS) began water- quality investigations at Summitville, Terrace #12;Figure 2. Aerial photographTransport Modeling of Reactive and Non- Reactive Constituents from Summitville, Colorado in the Wightman Fork/Alamosa River system downstream of the Summitville Mine, south-central Colorado, were

24

Modules based on the geochemical model PHREEQC for use in scripting and programming languages  

Science Conference Proceedings (OSTI)

The geochemical model PHREEQC is capable of simulating a wide range of equilibrium reactions between water and minerals, ion exchangers, surface complexes, solid solutions, and gases. It also has a general kinetic formulation that allows modeling of ... Keywords: C, C++, COM, Component object model, Fortran, Geochemical modeling, PHREEQC, Reactive-transport modeling

Scott R. Charlton; David L. Parkhurst

2011-10-01T23:59:59.000Z

25

Reactive transport in surface sediments I. Mexity and software quality  

Science Conference Proceedings (OSTI)

Analysis of three recent diagenetic model codes (OMEXDIA, CANDI and STEADYSED) revealed that codes have a rigid, static and problem-specific character, leaving little autonomy for the application user. The resulting lack of flexibility and extensibility, ... Keywords: early diagenesis, object-oriented design, problem-solving environment, reactive transport modelling, software quality assurance

Filip J. R. Meysman; Jack J. Middelburg; Peter M. J. Herman; Carlo H. R. Heip

2003-04-01T23:59:59.000Z

26

A sequential partly iterative approach for multicomponent reactive transport with CORE2D  

SciTech Connect

CORE{sup 2D} V4 is a finite element code for modeling partly or fully saturated water flow, heat transport and multicomponent reactive solute transport under both local chemical equilibrium and kinetic conditions. It can handle coupled microbial processes and geochemical reactions such as acid-base, aqueous complexation, redox, mineral dissolution/precipitation, gas dissolution/exsolution, ion exchange, sorption via linear and nonlinear isotherms, sorption via surface complexation. Hydraulic parameters may change due to mineral precipitation/dissolution reactions. Coupled transport and chemical equations are solved by using sequential iterative approaches. A sequential partly-iterative approach (SPIA) is presented which improves the accuracy of the traditional sequential noniterative approach (SNIA) and is more efficient than the general sequential iterative approach (SIA). While SNIA leads to a substantial saving of computing time, it introduces numerical errors which are especially large for cation exchange reactions. SPIA improves the efficiency of SIA because the iteration between transport and chemical equations is only performed in nodes with a large mass transfer between solid and liquid phases. The efficiency and accuracy of SPIA are compared to those of SIA and SNIA using synthetic examples and a case study of reactive transport through the Llobregat Delta aquitard in Spain. SPIA is found to be as accurate as SIA while requiring significantly less CPU time. In addition, SPIA is much more accurate than SNIA with only a minor increase in computing time. A further enhancement of the efficiency of SPIA is achieved by improving the efficiency of the Newton-Raphson method used for solving chemical equations. Such an improvement is obtained by working with increments of log-concentrations and ignoring the terms of the Jacobian matrix containing derivatives of activity coefficients. A proof is given for the symmetry and non-singularity of the Jacobian matrix. Numerical analyses performed with synthetic examples confirm that these modifications improve the efficiency and convergence of the iterative algorithm.

Samper, J.; Xu, T.; Yang, C.

2008-11-01T23:59:59.000Z

27

A comparison of results obtained with two subsurface non-isothermal multiphase reactive transport simulators, FADES-CORE and TOUGHREACT  

E-Print Network (OSTI)

saturated porous media with multiphase flow. FADES-CORE hasisothermal multiphase flow with reactive transport in porousmultiphase flow with multicomponent reactive transport in porous

Juncosa Rivera, Ricardo; Xu, Tianfu; Pruess, Karsten

2001-01-01T23:59:59.000Z

28

PFLOTRAN: Reactive Flow & Transport Code for Use on Laptops to Leadership-Class Supercomputers  

SciTech Connect

PFLOTRAN, a next-generation reactive flow and transport code for modeling subsurface processes, has been designed from the ground up to run efficiently on machines ranging from leadership-class supercomputers to laptops. Based on an object-oriented design, the code is easily extensible to incorporate additional processes. It can interface seamlessly with Fortran 9X, C and C++ codes. Domain decomposition parallelism is employed, with the PETSc parallel framework used to manage parallel solvers, data structures and communication. Features of the code include a modular input file, implementation of high-performance I/O using parallel HDF5, ability to perform multiple realization simulations with multiple processors per realization in a seamless manner, and multiple modes for multiphase flow and multicomponent geochemical transport. Chemical reactions currently implemented in the code include homogeneous aqueous complexing reactions and heterogeneous mineral precipitation/dissolution, ion exchange, surface complexation and a multirate kinetic sorption model. PFLOTRAN has demonstrated petascale performance using 2{sup 17} processor cores with over 2 billion degrees of freedom. Accomplishments achieved to date include applications to the Hanford 300 Area and modeling CO{sub 2} sequestration in deep geologic formations.

Hammond, Glenn E.; Lichtner, Peter C.; Lu, Chuan; Mills, Richard T.

2012-04-18T23:59:59.000Z

29

Variably Saturated Flow and Multicomponent Biogeochemical Reactive Transport Modeling of a Uranium Bioremediation Field Experiment  

Science Conference Proceedings (OSTI)

Field experiments at a former uranium mill tailings site have identified the potential for stimulating indigenous bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. This effectively removes uranium from solution resulting in groundwater concentrations below actionable standards. Three-dimensional, coupled variably-saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport rates and biogeochemical reaction rates that determine the location and magnitude of key reaction products. A comprehensive reaction network, developed largely through previous 1-D modeling studies, was used to simulate the impacts on uranium behavior of pulsed acetate amendment, seasonal water table variation, spatially-variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. A principal challenge is the mechanistic representation of biologically-mediated terminal electron acceptor process (TEAP) reactions whose products significantly alter geochemical controls on uranium mobility through increases in pH, alkalinity, exchangeable cations, and highly reactive reduction products. In general, these simulations of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado confirmed previously identified behaviors including (1) initial dominance by iron reducing bacteria that concomitantly reduce aqueous U(VI), (2) sulfate reducing bacteria that become dominant after {approx}30 days and outcompete iron reducers for the acetate electron donor, (3) continuing iron-reducer activity and U(VI) bioreduction during dominantly sulfate reducing conditions, and (4) lower apparent U(VI) removal from groundwater during dominantly sulfate reducing conditions. New knowledge on simultaneously active metal and sulfate reducers has been incorporated into the modeling. In this case, an initially small population of slow growing sulfate reducers is active from the initiation of biostimulation. Three-dimensional, variably saturated flow modeling was used to address impacts of a falling water table during acetate injection. These impacts included a significant reduction in aquifer saturated thickness and isolation of residual reactants and products, as well as unmitigated uranium, in the newly unsaturated vadose zone. High permeability sandy gravel structures resulted in locally high flow rates in the vicinity of injection wells that increased acetate dilution. In downgradient locations, these structures created preferential flow paths for acetate delivery that enhanced local zones of TEAP reactivity and subsidiary reactions. Conversely, smaller transport rates associated with the lower permeability lithofacies (e.g., fine) and vadose zone were shown to limit acetate access and reaction. Once accessed by acetate, however, these same zones limited subsequent acetate dilution and provided longer residence times that resulted in higher concentrations of TEAP products when terminal electron donors and acceptors were not limiting. Finally, facies-based porosity and reactive surface area variations were shown to affect aqueous uranium concentration distributions; however, the ranges were sufficiently small to preserve general trends. Large computer memory and high computational performance were required to simulate the detailed coupled process models for multiple biogeochemical components in highly resolved heterogeneous materials for the 110-day field experiment and 50 days of post-biostimulation behavior. In this case, a highly-scalable subsurface simulator operating on 128 processor cores for 12 hours was used to simulate each realization. An equivalent simulation without parallel processing would have taken 60 days, assuming sufficient memory was available.

Yabusaki, Steven B.; Fang, Yilin; Williams, Kenneth H.; Murray, Christopher J.; Ward, Anderson L.; Dayvault, Richard; Waichler, Scott R.; Newcomer, Darrell R.; Spane, Frank A.; Long, Philip E.

2011-11-01T23:59:59.000Z

30

Reactive transport modeling for CO2 geological sequestration  

E-Print Network (OSTI)

Geochemical detection of carbon dioxide in dilute aquifers.geological storage of carbon dioxide. Int. J. Greenhouse GasIPCC special report on carbon dioxide capture and storage.

Xu, T.

2013-01-01T23:59:59.000Z

31

Numerical Modeling of Coupled Variably-Saturated Fluid Flow and Reactive Transport with Fast and Slow Chemical Reactions  

SciTech Connect

The couplings among chemical reaction rates, advective and diffusive transport in fractured media or soils, and changes in hydraulic properties due to precipitation and dissolution within fractures and in rock matrix are important for both nuclear waste disposal and remediation of contaminated sites. This paper describes the development and application of LEHGC2.0, a mechanistically-based numerical model for simulation of coupled fluid flow and reactive chemical transport including both fast and slow reactions invariably saturated media. Theoretical bases and numerical implementations are summarized, and two example problems are demonstrated. The first example deals with the effect of precipitation-dissolution on fluid flow and matrix diffusion in a two-dimensional fractured media. Because of the precipitation and decreased diffusion of solute from the fracture into the matrix, retardation in the fractured medium is not as large as the case wherein interactions between chemical reactions and transport are not considered. The second example focuses on a complicated but realistic advective-dispersive-reactive transport problem. This example exemplifies the need for innovative numerical algorithms to solve problems involving stiff geochemical reactions.

LI, MING-HSU; SIEGEL, MALCOLM D.; YEH, GOUR-TSYH (GEORGE)

1999-09-20T23:59:59.000Z

32

Reactive transport model for the ambient unsaturated hydrogeochemical system at Yucca mountain, Nevada  

Science Conference Proceedings (OSTI)

To assist a technical review of a potential application for a geologic repository, a reactive transport model is presented for the ambient hydrogeochemical system at Yucca Mountain (YM). The model simulates two-phase, nonisothermal, advective and diffusive ... Keywords: Yucca mountain, geochemistry, groundwater chemistry, groundwater flow and transport, hydrology, reactive transport model, unsaturated zone

Lauren Browning; William M. Murphy; Chandrika Manepally; Randall Fedors

2003-04-01T23:59:59.000Z

33

Reactive transport in aquatic ecosystems: Rapid model prototyping in the open source software R  

Science Conference Proceedings (OSTI)

The concentrations of many natural compounds are altered by chemical and biological transformations, and physical processes such as adsorption and transport. Their fate can be predicted using reactive transport models that describe reaction and advective ... Keywords: Model, Open source, R, Reactive transport, Software

Karline Soetaert; Filip Meysman

2012-06-01T23:59:59.000Z

34

Lessons learned from reactive transport modeling of a low-activity waste glass disposal system  

Science Conference Proceedings (OSTI)

A set of reactive chemical transport calculations were conducted with the Subsurface Transport Over Reactive Multiphases (STORM) code to evaluate the long-term performance of a representative low-activity waste glass in a shallow subsurface disposal ... Keywords: chemical transport, low-level waste, numerical model, unsaturated flow, vadose zone

Diana H. Bacon; B. Peter McGrail

2003-04-01T23:59:59.000Z

35

Final Report Coupling in silico microbial models with reactive transport models to predict the fate of contaminants in the subsurface.  

Science Conference Proceedings (OSTI)

This project successfully accomplished its goal of coupling genome-scale metabolic models with hydrological and geochemical models to predict the activity of subsurface microorganisms during uranium bioremediation. Furthermore, it was demonstrated how this modeling approach can be used to develop new strategies to optimize bioremediation. The approach of coupling genome-scale metabolic models with reactive transport modeling is now well enough established that it has been adopted by other DOE investigators studying uranium bioremediation. Furthermore, the basic principles developed during our studies will be applicable to much broader investigations of microbial activities, not only for other types of bioremediation, but microbial metabolism in diversity of environments. This approach has the potential to make an important contribution to predicting the impact of environmental perturbations on the cycling of carbon and other biogeochemical cycles.

Lovley, Derek R.

2012-10-31T23:59:59.000Z

36

Numerical Simulation of the Transport of Chemically Reactive Species under Land- and Sea-Breeze Circulations  

Science Conference Proceedings (OSTI)

The characteristics of the transport of chemically reactive species under land- and sea-breeze (LSB) circulations are investigated using a detailed transport/chemistry model, which includes 84 gas-phase and 10 heterogeneous chemical reactions. ...

Toshihiro Kitada; Gregory R. Carmichael; Leonard K. Peters

1984-08-01T23:59:59.000Z

37

TACK: a program coupling chemical kinetics with a two-dimensional transport model in geochemical systems  

Science Conference Proceedings (OSTI)

The Transport And Chemical Kinetics (TACK) program has been designed to make predictions of the chemistry in the vicinity of a planned repository for nuclear waste, i.e. SFL 3-5, where SFL is the Swedish abbreviation for "Swedish repository for long-lived ... Keywords: coupled, diffusion, dispersion, reaction, transport, two-dimensional

Göran Källvenius; Christian Ekberg

2003-05-01T23:59:59.000Z

38

Coupled modeling of non-isothermal multiphase flow, solute transport and reactive chemistry in porous and fractured media: 1. Model Development and Validation  

E-Print Network (OSTI)

multiphase reactive transport, in Reactive transport in porousporous and fractured media under non-isothermal multiphaseporous and fractured media under non-isothermal multiphase

Xu, Tianfu; Pruess, Karsten

1998-01-01T23:59:59.000Z

39

A transport based one-dimensional perturbation code for reactivity calculations in metal systems  

SciTech Connect

A one-dimensional reactivity calculation code is developed using first order perturbation theory. The reactivity equation is based on the multi-group transport equation using the discrete ordinates method for angular dependence. In addition to the first order perturbation approximations, the reactivity code uses only the isotropic scattering data, but cross section libraries with higher order scattering data can still be used with this code. The reactivity code obtains all the flux, cross section, and geometry data from the standard interface files created by ONEDANT, a discrete ordinates transport code. Comparisons between calculated and experimental reactivities were done with the central reactivity worth data for Lady Godiva, a bare uranium metal assembly. Good agreement is found for isotopes that do not violate the assumptions in the first order approximation. In general for cases where there are large discrepancies, the discretized cross section data is not accurately representing certain resonance regions that coincide with dominant flux groups in the Godiva assembly. Comparing reactivities calculated with first order perturbation theory and a straight {Delta}k/k calculation shows agreement within 10% indicating the perturbation of the calculated fluxes is small enough for first order perturbation theory to be applicable in the modeled system. Computation time comparisons between reactivities calculated with first order perturbation theory and straight {Delta}k/k calculations indicate considerable time can be saved performing a calculation with a perturbation code particularly as the complexity of the modeled problems increase.

Wenz, T.R.

1995-02-01T23:59:59.000Z

40

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

Science Conference Proceedings (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 ... Keywords: CO2 geological storage, Environmental remediation, Multi-phase flow, Nuclear waste geological disposal, Reactive transport, TOUGHREACT

Tianfu Xu; Nicolas Spycher; Eric Sonnenthal; Guoxiang Zhang; Liange Zheng; Karsten Pruess

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Using reactive transport modeling to evaluate the source term at Yucca mountain  

Science Conference Proceedings (OSTI)

The conventional approach of source-term evaluation for performance assessment of nuclear waste repositories uses the dissolution rate of waste form and the solubility of pure phases of radioactive elements to constrain radionuclide concentrations. This ... Keywords: neptunium, nuclear waste, radionuclide solubility, reactive-transport modeling, secondary phases, spent nuclear fuel, uranium

Yueting Chen

2003-04-01T23:59:59.000Z

42

Multicomponent reactive transport modeling at the Ratones uranium mine, Cceres (Spain)  

E-Print Network (OSTI)

management. The Ratones uranium mine was abandoned and flooded in 1974. Due to its reducing undergroundMulticomponent reactive transport modeling at the Ratones uranium mine, Cáceres (Spain) Modelación/06/05 / Accepted: 02/10/05 Abstract Flooding of abandoned mines may have a major impact in groundwater quality

Politècnica de Catalunya, Universitat

43

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

Science Conference Proceedings (OSTI)

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.

Zhang, Fan [ORNL; Yeh, Gour-Tsyh [University of Central Florida, Orlando; Parker, Jack C [ORNL; Brooks, Scott C [ORNL; Pace, Molly [ORNL; Kim, Young Jin [ORNL; Jardine, Philip M [ORNL; Watson, David B [ORNL

2007-01-01T23:59:59.000Z

44

TOURGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media  

E-Print Network (OSTI)

flows of multiphase fluids in porous and fractured media.multiphase fluid and heat flow. The program is applicable to porous

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-01-01T23:59:59.000Z

45

TOURGHREACT: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media  

E-Print Network (OSTI)

for modeling fluid and heat flow in fractured porous media.flows of multiphase fluids in porous and fractured media.

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-01-01T23:59:59.000Z

46

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive geochemical Transport in Variable Saturated Geologic Media  

E-Print Network (OSTI)

for modeling fluid and heat flow in fractured porous media:1985) for fluid and heat flow in fractured porous media. The

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2004-01-01T23:59:59.000Z

47

Reactive Geochemical Transport Modeling of Concentrated Aqueous Solutions: Supplement to TOUGHREACT User's Guide for the Pitzer Ion-Interaction Model  

E-Print Network (OSTI)

144 o C. A water-cooled condenser was attached at the top ofthe end block (at the condenser outflow) is allowed contactis condensed in the condenser, represented by a cooler block

Zhang, Guoxiang; Spycher, Nicolas; Xu, Tianfu; Sonnenthal, Eric; Steefel, Carl

2006-01-01T23:59:59.000Z

48

Subsurface Transport Over Reactive Multiphases (STORM): A general, coupled, nonisothermal multiphase flow, reactive transport, and porous medium alteration simulator, Version 2 user's guide  

Science Conference Proceedings (OSTI)

The Hanford Site, in southeastern Washington State, has been used extensively to produce nuclear materials for the US strategic defense arsenal by the Department of Energy (DOE) and its predecessors, the US Atomic Energy Commission and the US Energy Research and Development Administration. A large inventory of radioactive and mixed waste has accumulated in 177 buried single- and double shell tanks. Liquid waste recovered from the tanks will be pretreated to separate the low-activity fraction from the high-level and transuranic wastes. Vitrification is the leading option for immobilization of these wastes, expected to produce approximately 550,000 metric tons of Low Activity Waste (LAW) glass. This total tonnage, based on nominal Na{sub 2}O oxide loading of 20% by weight, is destined for disposal in a near-surface facility. Before disposal of the immobilized waste can proceed, the DOE must approve a performance assessment, a document that described the impacts, if any, of the disposal facility on public health and environmental resources. Studies have shown that release rates of radionuclides from the glass waste form by reaction with water determine the impacts of the disposal action more than any other independent parameter. This report describes the latest accomplishments in the development of a computational tool, Subsurface Transport Over Reactive Multiphases (STORM), Version 2, a general, coupled non-isothermal multiphase flow and reactive transport simulator. The underlying mathematics in STORM describe the rate of change of the solute concentrations of pore water in a variably saturated, non-isothermal porous medium, and the alteration of waste forms, packaging materials, backfill, and host rocks.

DH Bacon; MD White; BP McGrail

2000-03-07T23:59:59.000Z

49

Development and feasibility of a waste package coupled reactive transport model (AREST-CT)  

Science Conference Proceedings (OSTI)

Most models that analyze the waste package and engineered barrier system (near-field) of an underground geologic repository assume constant boundary conditions at the waste form surface and constant chemical properties of the groundwater. These models are useful for preliminary modeling, iterative modeling to estimate uncertainties, and as a source for a total systems analysis. However, the chemical behavior of the system is a very important factor in the containment and release of radionuclides, and one needs to understand the underlying processes involved. Therefore, the authors are developing a model to couple the calculation of the chemical properties with the reactive transport which can be used to assess the near-field. This report describes the models being implemented and presents some simple analyses demonstrating the feasibility of the chemical and coupled transport models.

Engel, D.W.; McGrail, B.P.; Fort, J.A.; Roberts, J.S.

1994-05-01T23:59:59.000Z

50

Mercury Geochemical, Groundwater Geochemical, And Radiometric Geophysical  

Open Energy Info (EERE)

Geochemical, Groundwater Geochemical, And Radiometric Geophysical Geochemical, Groundwater Geochemical, And Radiometric Geophysical Signatures At Three Geothermal Prospects In Northern Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Mercury Geochemical, Groundwater Geochemical, And Radiometric Geophysical Signatures At Three Geothermal Prospects In Northern Nevada Details Activities (14) Areas (3) Regions (0) Abstract: Ground water sampling, desorbed mercury soil geochemical surveys and a radiometric geophysical survey was conducted in conjunction with geological mapping at three geothermal prospects in northern Nevada. Orientation sample lines from 610 m (2000 ft.) to 4575 m (15,000 ft.) in length were surveyed at right angles to known and suspected faults. Scintillometer readings (gamma radiation - total counts / second) were also

51

Up-Scaling Geochemical Reaction Rates for Carbon Dioxide (CO2) in Deep Saline Aquifers  

Science Conference Proceedings (OSTI)

The overall goal of the project was to bridge the gap between our knowledge of small-scale geochemical reaction rates and reaction rates meaningful for modeling transport at core scales. The working hypothesis was that reaction rates, determined from laboratory measurements based upon reactions typically conducted in well mixed batch reactors using pulverized reactive media may be significantly changed in in situ porous media flow due to rock microstructure heterogeneity. Specifically we hypothesized that, generally, reactive mineral surfaces are not uniformly accessible to reactive fluids due to the random deposition of mineral grains and to the variation in flow rates within a pore network. Expected bulk reaction rates would therefore have to be correctly up-scaled to reflect such heterogeneity. The specific objective was to develop a computational tool that integrates existing measurement capabilities with pore-scale network models of fluid flow and reactive transport. The existing measurement capabilities to be integrated consisted of (a) pore space morphology, (b) rock mineralogy, and (c) geochemical reaction rates. The objective was accomplished by: (1) characterizing sedimentary sandstone rock morphology using X-ray computed microtomography, (2) mapping rock mineralogy using back-scattered electron microscopy (BSE), X-ray dispersive spectroscopy (EDX) and CMT, (3) characterizing pore-accessible reactive mineral surface area, and (4) creating network models to model acidic CO{sub 2} saturated brine injection into the sandstone rock samples.

Lindquist, W Brent

2009-03-03T23:59:59.000Z

52

Chombo-Crunch: Modeling Pore-Scale Reactive Transport in Carbon  

NLE Websites -- All DOE Office Websites (Extended Search)

Transient pH on calcite grains in capillary tube experiment. 1 billion grid points computed on 48K cores. 1 micron resolution. Transient pH on calcite grains in capillary tube experiment. 1 billion grid points computed on 48K cores. 1 micron resolution. Transient pH on calcite grains in capillary tube experiment. 1 billion grid points computed on 48K cores. 1 micron resolution. David Trebotich, Lawrence Berkeley National Laboratory Chombo-Crunch: Modeling Pore-Scale Reactive Transport in Carbon Sequestration PI Name: David Trebotich PI Email: treb@lbl.gov Institution: Lawrence Berkeley National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 80 Million Year: 2014 Research Domain: Earth Science Carbon sequestration, the process of capturing carbon dioxide (CO2) before it enters the atmosphere and transferring it into the earth, is a promising technique to help control greenhouse gas emissions. Researchers from the

53

Release of aged contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport  

Science Conference Proceedings (OSTI)

Hanford sediments impacted by hyperalkaline high level radioactive waste have undergone incongruent silicate mineral weathering concurrent with contaminant uptake. In this project, we studied the impact of background pore water (BPW) on strontium, cesium and iodine desorption and transport in Hanford sediments that were experimentally weathered by contact with simulated hyperalkaline tank waste leachate (STWL) solutions. Using those lab-weathered Hanford sediments (HS) and model precipitates formed during nucleation from homogeneous STWL solutions (HN), we (i) provided thorough characterization of reaction products over a matrix of field-relevant gradients in contaminant concentration, partial pressure of carbon dioxide, and reaction time; (ii) improved molecular-scale understanding of how sorbate speciation controls contaminant desorption from weathered sediments upon removal of caustic sources; and (iii) developed a mechanistic, predictive model of meso- to field-scale contaminant reactive transport under these conditions. In this final report, we provide detailed descriptions of our results from this three-year study, completed in 2012 following a one-year no cost extension.

Chorover, Jon; Perdrial, Nico; Mueller, Karl; Strepka, Caleb; OĂƒ ƒ Ă‚ Â˘Ăƒ ‚ Ă‚ € Ăƒ ‚ Ă‚ ™ Day, Peggy; Rivera, Nelson; Um, Wooyong; Chang, Hyun-Shik; Steefel, Carl; Thompson, Aaron

2012-11-05T23:59:59.000Z

54

A Three-Dimensional Level Set Simulation of Coupled Reactive Transport and Precipitation/Dissolution  

Science Conference Proceedings (OSTI)

Direct simulation of reactive transport in porous media is challenging due to the difficulty of tracking the dynamics of evolving solid-fluid interfaces. To meet this challenge, a level set method for capturing interface evolution due to dissolution and/or precipitation has been integrated into the standard grid-based finite-difference approach for simulating flow and transport in complex geometries. Based on the level set description of the interface geometry, Chorin’s projection method was modified to approximately satisfy the nonslip boundary condition at the grain surface, and a sharp interface methodwas developed for calculating the concentration field near the grain surface in the presence of surface reaction. Compared with the pixel representations of the interface used in other methods, the sub-grid representation using level set method offers significantly improved accuracy and efficiency. The advantage of the method is demonstrated in a systematic investigation of precipitation/dissolution in a simple three dimensional pore-throat with varying throat apertures. The simulation was first validated in a grid-refinement study. The effects of flow conditions, reaction rates and three-dimensional geometries are explored both qualitatively and quantitatively. The permeability-porosity relationship calculated from simulations is compared with Carman-Kozeny constitutive models to illustrate the limited capability of these empirical models, which are based on simplified pore-scale geometries and conditions.

Xiaoyi Li; Hai Huang; Paul Meakin

2010-06-01T23:59:59.000Z

55

A reactive transport modeling approach to simulate biogeochemical processes in pore structures with pore-scale heterogeneities  

Science Conference Proceedings (OSTI)

Redox processes, including degradation of organic contaminants, are often controlled by microorganisms residing in natural porous media like soils or aquifers. These environments are characterized by heterogeneities at various scales which influence ... Keywords: Bioavailability, Biodegradation, Pore networks, Pore-scale heterogeneity, Reactive transport models, Spatial distributions

Mehdi Gharasoo; Florian Centler; Pierre Regnier; Hauke Harms; Martin Thullner

2012-04-01T23:59:59.000Z

56

REACTIVE TRANSPORT MODELING USING A PARALLEL FULLY-COUPLED SIMULATOR BASED ON PRECONDITIONED JACOBIAN-FREE NEWTON-KRYLOV  

SciTech Connect

Systems of multicomponent reactive transport in porous media that are large, highly nonlinear, and tightly coupled due to complex nonlinear reactions and strong solution-media interactions are often described by a system of coupled nonlinear partial differential algebraic equations (PDAEs). A preconditioned Jacobian-Free Newton-Krylov (JFNK) solution approach is applied to solve the PDAEs in a fully coupled, fully implicit manner. The advantage of the JFNK method is that it avoids explicitly computing and storing the Jacobian matrix during Newton nonlinear iterations for computational efficiency considerations. This solution approach is also enhanced by physics-based blocking preconditioning and multigrid algorithm for efficient inversion of preconditioners. Based on the solution approach, we have developed a reactive transport simulator named RAT. Numerical results are presented to demonstrate the efficiency and massive scalability of the simulator for reactive transport problems involving strong solution-mineral interactions and fast kinetics. It has been applied to study the highly nonlinearly coupled reactive transport system of a promising in situ environmental remediation that involves urea hydrolysis and calcium carbonate precipitation.

Luanjing Guo; Chuan Lu; Hai Huang; Derek R. Gaston

2012-06-01T23:59:59.000Z

57

An investigation of the effect of pore scale flow on average geochemical reaction rates using direct numerical simulation  

Science Conference Proceedings (OSTI)

The scale-dependence of geochemical reaction rates hinders their use in continuum scale models intended for the interpretation and prediction of chemical fate and transport in subsurface environments such as those considered for geologic sequestration of CO{sub 2}. Processes that take place at the pore scale, especially those involving mass transport limitations to reactive surfaces, may contribute to the discrepancy commonly observed between laboratory-determined and continuum-scale or field rates. Here, the dependence of mineral dissolution rates on the pore structure of the porous media is investigated by means of pore scale modeling of flow and multicomponent reactive transport. The pore scale model is comprised of high performance simulation tools and algorithms for incompressible flow and conservative transport combined with a general-purpose multicomponent geochemical reaction code. The model performs direct numerical simulation of reactive transport based on an operator-splitting approach to coupling transport and reactions. The approach is validated with a Poiseuille flow single-pore experiment and verified with an equivalent 1D continuum-scale model of a capillary tube packed with calcite spheres. Using the case of calcite dissolution as an example, the high resolution model is used to demonstrate that non-uniformity in the flow field at the pore scale has the effect of decreasing the overall reactivity of the system, even when systems with identical reactive surface area are considered. The effect becomes more pronounced as the heterogeneity of the reactive grain packing increases, particularly where the flow slows sufficiently such that the solution approaches equilibrium locally and the average rate becomes transport-limited.

Rafa, S. Molins; Trebotich, D.; Steefel, C. I.; Shen, C.

2012-02-01T23:59:59.000Z

58

The Development and Application of Reactive Transport Modeling Techniques to Study Radionuclide Migration at Yucca Mountain, NV  

SciTech Connect

Yucca Mountain, Nevada has been chosen as a possible site for the first high level radioactive waste repository in the United States. As part of the site investigation studies, we need to make scientifically rigorous estimations of radionuclide migration in the event of a repository breach. Performance assessment models used to make these estimations are computationally intensive. We have developed two reactive transport modeling techniques to simulate radionuclide transport at Yucca Mountain: (1) the selective coupling approach applied to the convection-dispersion-reaction (CDR) model and (2) a reactive stream tube approach (RST). These models were designed to capture the important processes that influence radionuclide migration while being computationally efficient. The conventional method of modeling reactive transport models is to solve a coupled set of multi-dimensional partial differential equations for the relevant chemical components in the system. We have developed an iterative solution technique, denoted the selective coupling method, that represents a versatile alternative to traditional uncoupled iterative techniques and the filly coupled global implicit method. We show that selective coupling results in computational and memory savings relative to these approaches. We develop RST as an alternative to the CDR method for solving large two- or three-dimensional reactive transport simulations for cases in which one is interested in predicting the flux across a specific control plane. In the RST method, the multidimensional problem is reduced to a series of one-dimensional transport simulations along streamlines. The key assumption with RST is that mixing at the control plane approximates the transverse dispersion between streamlines. We compare the CDR and RST approaches for several scenarios that are relevant to the Yucca Mountain Project. For example, we apply the CDR and RST approaches to model an ongoing field experiment called the Unsaturated Zone Transport Test.

Hari Selvi Viswanathan

1999-09-01T23:59:59.000Z

59

Reaction-Based Reactive Transport Modeling of Fe(III) and U(V) Reduction  

SciTech Connect

Our new research project (started Fall 2004) was funded by a grant to The Pennsylvania State University, University of Central Florida, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Our previous NABIR project (DE-FG02-01ER63180/63181/63182, funded within the Biotransformation Element) focused on (1) microbial reduction of Fe(III) and U(VI) individually, and concomitantly in natural sediments, (2) Fe(III) oxide surface chemistry, specifically with respect to reactions with Fe(II) and U(VI), (3) the influence of humic substances on Fe(III) and U(VI) bioreduction, and on U(VI) complexation, and (4) the development of reaction-based reactive transport biogeochemical models to numerically simulate our experimental results. The new project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

Burgos, William D.; Roden, Eric E.; Yeh, Gour-Tsyh

2005-06-01T23:59:59.000Z

60

History of Geochemical Modeling  

Science Conference Proceedings (OSTI)

Table 1   Sources of geochemical modeling software...www.telusplanet.net/public/geogams/index SOLVEQ/CHILLER Mark H. Reed Department of Geological

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While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
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61

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)  

E-Print Network (OSTI)

of geological porous media with multiphase flow: Theory andmultiphase flow, solute transport andreactive chemistry in porousMultiphase Fluid Flow, Heat Transfer, and Deformation in Fractured Porous

Steefel, Carl

2010-01-01T23:59:59.000Z

62

Upscaling reactive transport in porous media : laboratory visualization and stochastic models  

E-Print Network (OSTI)

Solute transport models are essential tools for understanding and forecasting chemical concentrations in groundwater. Advection-dispersion based models can adequately predict spatial averages of conservative solute ...

Oates, Peter M. (Peter Michael), 1977-

2007-01-01T23:59:59.000Z

63

Final Project Report: Release of aged contaminants from weathered sediments: Effects of sorbate speciation on scaling of reactive transport  

SciTech Connect

Hanford sediments impacted by hyperalkaline high level radioactive waste have undergone incongruent silicate mineral weathering concurrent with contaminant uptake. In this project, we studied the impact of background pore water (BPW) on strontium, cesium and iodine desorption and transport in Hanford sediments that were experimentally weathered by contact with simulated hyperalkaline tank waste leachate (STWL) solutions. Using those lab-weathered Hanford sediments (HS) and model precipitates formed during nucleation from homogeneous STWL solutions (HN), we (i) provided detailed characterization of reaction products over a matrix of field-relevant gradients in contaminant concentration, PCO2, and reaction time; (ii) improved molecular-scale understanding of how sorbate speciation controls contaminant desorption from weathered sediments upon removal of caustic sources; and (iii) developed a mechanistic, predictive model of meso- to field-scale contaminant reactive transport under these conditions.

Jon Chorover, University of Arizona; Peggy O' €  ™ Day, University of California, Merced; Karl Mueller, Penn State University; Wooyong Um, Pacific Northwest National Laboratory; Carl Steefel, Lawrence Berkeley National Laboratory

2012-10-01T23:59:59.000Z

64

Geochemical Techniques | Open Energy Information  

Open Energy Info (EERE)

Geochemical Techniques Geochemical Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Geochemical Techniques Details Activities (0) Areas (0) Regions (0) NEPA(1) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: None Parent Exploration Technique: Exploration Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Geochemical Techniques: No definition has been provided for this term. Add a Definition Related Techniques Geochemical Techniques Geochemical Data Analysis Geothermometry Gas Geothermometry Isotope Geothermometry Liquid Geothermometry Cation Geothermometers Multicomponent Geothermometers Silica Geothermometers Thermal Ion Dispersion

65

Multiphase Reactive Transport modeling of Stable Isotope Fractionation of Infiltrating Unsaturated Zone Pore Water and Vapor Using TOUGHREACT  

Science Conference Proceedings (OSTI)

Numerical simulations of transport and isotope fractionation provide a method to quantitatively interpret vadose zone pore water stable isotope depth profiles based on soil properties, climatic conditions, and infiltration. We incorporate the temperature-dependent equilibration of stable isotopic species between water and water vapor, and their differing diffusive transport properties into the thermodynamic database of the reactive transport code TOUGHREACT. These simulations are used to illustrate the evolution of stable isotope profiles in semiarid regions where recharge during wet seasons disturbs the drying profile traditionally associated with vadose zone pore waters. Alternating wet and dry seasons lead to annual fluctuations in moisture content, capillary pressure, and stable isotope compositions in the vadose zone. Periodic infiltration models capture the effects of seasonal increases in precipitation and predict stable isotope profiles that are distinct from those observed under drying (zero infiltration) conditions. After infiltration, evaporation causes a shift to higher 18O and D values, which are preserved in the deeper pore waters. The magnitude of the isotopic composition shift preserved in deep vadose zone pore waters varies inversely with the rate of infiltration.

Singleton, Michael J.; Sonnenthal, Eric L.; Conrad, Mark E.; DePaolo, Donald J.

2003-08-28T23:59:59.000Z

66

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1  

E-Print Network (OSTI)

mineralogic model of Yucca Mountain, Nevada, Rev 2.0 . , Losfrom tuffs at Yucca Mountain, Nevada, USA. Geochim.in zeolitized tuffs at Yucca Mountain, Nevada, USA. Geochim.

Xu, Tianfu

2008-01-01T23:59:59.000Z

67

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1  

E-Print Network (OSTI)

for modeling fluid and heat flow in fractured porous media:1985) for fluid and heat flow in fractured porous media. The

Xu, Tianfu

2008-01-01T23:59:59.000Z

68

TOUGHREACT User's Guide: A Simulation Program for Non-isothermal Multiphase Reactive Geochemical Transport in Variably Saturated Geologic Media, V1.2.1  

E-Print Network (OSTI)

Drift, heat was applied solely to the drift-center gridsquares) indicate grid block coordinates. Heat was appliedgrid block KCYC=KCYC+1 Time step: ?t Solve fluid and heat

Xu, Tianfu

2008-01-01T23:59:59.000Z

69

Reactive-Transport Simulation of Phosphorus in the Sewage Plume at the  

E-Print Network (OSTI)

to develop the base-case and revised models was PHAST (Parkhurst and others, 1995; Parkhurst and Kipp, 2002). PHAST couples capabilities to simulate ground-water flow and associated solute transport with #12 of PHAST are derived from HST3D (Kipp, 1997) and the chemical reaction part of the model is derived from

70

Simulation of reactive transport of uranium(VI) in groundwater with variable chemical conditions  

E-Print Network (OSTI)

transport of U(VI) in an alluvial aquifer at a former uranium ore-processing mill near Naturita, CO. The SCM alluvial aquifer beneath a former U(VI) mill located near Naturita, CO, was simulated using a surface. Site Characterization 2.1. Site Description [9] The former uranium mill site is approximately 3 km

71

Optical and electron transport properties of reactively sputtered Cu/sub x/S  

DOE Green Energy (OSTI)

Thin films of Cu/sub x/S were deposited on glass slides by sputtering Cu in a reactive H/sub 2/S/Ar environment. Optical transmittance and reflectance measurements were used to explore the infrared absorption spectra of the material. Analysis of the absorption edge characteristics resulted in the identification of an indirect bandgap at 1.15 (+-.05) eV, a direct bandgap at 1.30 (+-.05) eV, and an electron effective mass of 1.0 (+-0.2) m/sub 0/. Electrical data consisting of resistivity and Hall effect measurements from liquid nitrogen to room temperature were analyzed to determine the dominant scattering mechanisms limiting the hole mobility in the material. Ionized impurity scattering was the dominant mechanism at low temperatures (T < 100/sup 0/K) and polar optical phonon scattering was most effective at high temperatures (T > 150/sup 0/K). All films were p-type. Effects of sputtering gas pressure, heat treatments, and temperature on the properties were studied.

Leong, J.Y.C.

1980-06-30T23:59:59.000Z

72

Thermodynamic Data for Geochemical Modeling of Carbonate Reactions Associated with CO2 Sequestration – Literature Review  

Science Conference Proceedings (OSTI)

Permanent storage of anthropogenic CO2 in deep geologic formations is being considered as a means to reduce the concentration of atmospheric CO2 and thus its contribution to global climate change. To ensure safe and effective geologic sequestration, numerous studies have been completed of the extent to which the CO2 migrates within geologic formations and what physical and geochemical changes occur in these formations when CO2 is injected. Sophisticated, computerized reservoir simulations are used as part of field site and laboratory CO2 sequestration studies. These simulations use coupled multiphase flow-reactive chemical transport models and/or standalone (i.e., no coupled fluid transport) geochemical models to calculate gas solubility, aqueous complexation, reduction/oxidation (redox), and/or mineral solubility reactions related to CO2 injection and sequestration. Thermodynamic data are critical inputs to modeling geochemical processes. The adequacy of thermodynamic data for carbonate compounds has been identified as an important data requirement for the successful application of these geochemical reaction models to CO2 sequestration. A review of thermodynamic data for CO2 gas and carbonate aqueous species and minerals present in published data compilations and databases used in geochemical reaction models was therefore completed. Published studies that describe mineralogical analyses from CO2 sequestration field and natural analogue sites and laboratory studies were also reviewed to identify specific carbonate minerals that are important to CO2 sequestration reactions and therefore require thermodynamic data. The results of the literature review indicated that an extensive thermodynamic database exists for CO2 and CH4 gases, carbonate aqueous species, and carbonate minerals. Values of ?fG298° and/or log Kr,298° are available for essentially all of these compounds. However, log Kr,T° or heat capacity values at temperatures above 298 K exist for less than approximately one-third of these compounds. Because the temperatures of host formations that will be used for CO2 injection and sequestration will be at tempera¬tures in the range of 50şC to 100şC or greater, the lack of high temperature thermodynamic values for key carbonate compounds especially minerals, will impact the accuracy of some modeling calculations.

Krupka, Kenneth M.; Cantrell, Kirk J.; McGrail, B. Peter

2010-09-28T23:59:59.000Z

73

Geochemical Enhancement Of Enhanced Geothermal System Reservoirs: An Integrated Field And Geochemical Approach  

DOE Green Energy (OSTI)

The geochemical effects of injecting fluids into geothermal reservoirs are poorly understood and may be significantly underestimated. Decreased performance of injection wells has been observed in several geothermal fields after only a few years of service, but the reasons for these declines has not been established. This study had three primary objectives: 1) determine the cause(s) of the loss of injectivity; 2) utilize these observations to constrain numerical models of water-rock interactions; and 3) develop injection strategies for mitigating and reversing the potential effects of these interactions. In this study rock samples from original and redrilled injection wells at Coso and the Salton Sea geothermal fields, CA, were used to characterize the mineral and geochemical changes that occurred as a result of injection. The study documented the presence of mineral scales and at both fields in the reservoir rocks adjacent to the injection wells. At the Salton Sea, the scales consist of alternating layers of fluorite and barite, accompanied by minor anhydrite, amorphous silica and copper arsenic sulfides. Amorphous silica and traces of calcite were deposited at Coso. The formation of silica scale at Coso provides an example of the effects of untreated (unacidified) injectate on the reservoir rocks. Scanning electron microscopy and X-ray diffractometry were used to characterize the scale deposits. The silica scale in the reservoir rocks at Coso was initially deposited as spheres of opal-A 1-2 micrometers in diameter. As the deposits matured, the spheres coalesced to form larger spheres up to 10 micrometer in diameter. Further maturation and infilling of the spaces between spheres resulted in the formation of plates and sheets that substantially reduce the original porosity and permeability of the fractures. Peripheral to the silica deposits, fluid inclusions with high water/gas ratios provide a subtle record of interactions between the injectate and reservoir rocks. In contrast, fluid inclusions trapped prior to injection are relatively gas rich. These results suggest that the rocks undergo extensive microfracturing during injection and that the composition of the fluid inclusions will be biased toward the youngest event. Interactions between the reservoir rocks and injectate were modeled using the non-isothermal reactive geochemical transport code TOUGHREACT. Changes in fluid pH, fracture porosity, fracture permeability, fluid temperature, and mineral abundances were monitored. The simulations predict that amorphous silica will precipitate primarily within a few meters of the injection well and that mineral deposition will lead to rapid declines in fracture porosity and permeability, consistent with field observations. In support of Enhanced Geothermal System development, petrologic studies of Coso well 46A-19RD were conducted to determine the regions that are most likely to fail when stimulated. These studies indicate that the most intensely brecciated and altered rocks in the zone targeted for stimulation (below 10,000 ft (3048 m)) occur between 11,200 and 11,350 ft (3414 and 3459 m). This zone is interpreted as a shear zone that initially juxtaposed quartz diorite against granodiorite. Strong pervasive alteration and veining within the brecciated quartz diorite and granodiorite suggest this shear zone was permeable in the past. This zone of weakness was subsequently exploited by a granophyre dike whose top occurs at 11,350 ft (3459 m). The dike is unaltered. We anticipate, based on analysis of the well samples that failure during stimulation will most likely occur on this shear zone.

Joseph N. Moore

2007-12-31T23:59:59.000Z

74

Geochemical Data Analysis | Open Energy Information  

Open Energy Info (EERE)

Geochemical Data Analysis Geochemical Data Analysis Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Geochemical Data Analysis Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Geochemical Techniques Exploration Sub Group: Geochemical Data Analysis Parent Exploration Technique: Geochemical Techniques Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Geochemical Data Analysis: No definition has been provided for this term. Add a Definition References No exploration activities found. Print PDF Retrieved from "http://en.openei.org/w/index.php?title=Geochemical_Data_Analysis&oldid=594157" Categories: Geochemical Techniques Exploration Techniques

75

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

SciTech Connect

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.

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

2003-01-08T23:59:59.000Z

76

Modeling of coupled heat transfer and reactive transport processesin porous media: Application to seepage studies at Yucca Mountain, Nevada  

SciTech Connect

When hot radioactive waste is placed in subsurface tunnels, a series of complex changes occurs in the surrounding medium. The water in the pore space of the medium undergoes vaporization and boiling. Subsequently, vapor migrates out of the matrix pore space, moving away from the tunnel through the permeable fracture network. This migration is propelled by buoyancy, by the increased vapor pressure caused by heating and boiling, and through local convection. In cooler regions, the vapor condenses on fracture walls, where it drains through the fracture network. Slow imbibition of water thereafter leads to gradual rewetting of the rock matrix. These thermal and hydrological processes also bring about chemical changes in the medium. Amorphous silica precipitates from boiling and evaporation, and calcite from heating and CO2 volatilization. The precipitation of amorphous silica, and to a much lesser extent calcite, results in long-term permeability reduction. Evaporative concentration also results in the precipitation of gypsum (or anhydrite), halite, fluorite and other salts. These evaporative minerals eventually redissolve after the boiling period is over, however, their precipitation results in a significant temporary decrease in permeability. Reduction of permeability is also associated with changes in fracture capillary characteristics. In short, the coupled thermal-hydrological-chemical (THC) processes dynamically alter the hydrological properties of the rock. A model based on the TOUGHREACT reactive transport software is presented here to investigate the impact of THC processes on flow near an emplacement tunnel at Yucca Mountain, Nevada. We show how transient changes in hydrological properties caused by THC processes often lead to local flow channeling and saturation increases above the tunnel. For models that include only permeability changes to fractures, such local flow channeling may lead to seepage relative to models where THC effects are ignored. However, coupled THC seepage models that include both permeability and capillary changes to fractures may not show this additional seepage.

Mukhopadhyay, Sumit; Sonnenthal, Eric L.; Spycher, Nicolas

2007-01-15T23:59:59.000Z

77

Modeling of coupled heat transfer and reactive transport processesin porous media: Application to seepage studies at Yucca Mountain, Nevada  

SciTech Connect

When hot radioactive waste is placed in subsurface tunnels, a series of complex changes occurs in the surrounding medium. The water in the pore space of the medium undergoes vaporization and boiling. Subsequently, vapor migrates out of the matrix pore space, moving away from the tunnel through the permeable fracture network. This migration is propelled by buoyancy, by the increased vapor pressure caused by heating and boiling, and through local convection. In cooler regions, the vapor condenses on fracture walls, where it drains through the fracture network. Slow imbibition of water thereafter leads to gradual rewetting of the rock matrix. These thermal and hydrological processes also bring about chemical changes in the medium. Amorphous silica precipitates from boiling and evaporation, and calcite from heating and CO{sub 2} volatilization. The precipitation of amorphous silica, and to a much lesser extent calcite, results in long-term permeability reduction. Evaporative concentration also results in the precipitation of gypsum (or anhydrite), halite, fluorite and other salts. These evaporative minerals eventually redissolve after the boiling period is over, however, their precipitation results in a significant temporary decrease in permeability. Reduction of permeability is also associated with changes in fracture capillary characteristics. In short, the coupled thermal-hydrological-chemical (THC) processes dynamically alter the hydrological properties of the rock. A model based on the TOUGHREACT reactive transport software is presented here to investigate the impact of THC processes on flow near an emplacement tunnel at Yucca Mountain, Nevada. We show how transient changes in hydrological properties caused by THC processes often lead to local flow channeling and saturation increases above the tunnel. For models that include only permeability changes to fractures, such local flow channeling may lead to seepage relative to models where THC effects are ignored. However, coupled THC seepage models that include both permeability and capillary changes to fractures may not show this additional seepage.

Mukhopadhyay, S.; Sonnenthal, E.L.; Spycher, N.

2007-01-15T23:59:59.000Z

78

An adaptive sparse-grid high-order stochastic collocation method for Bayesian inference in groundwater reactive transport modeling  

SciTech Connect

Although Bayesian analysis has become vital to the quantification of prediction uncertainty in groundwater modeling, its application has been hindered due to the computational cost associated with numerous model executions needed for exploring the posterior probability density function (PPDF) of model parameters. This is particularly the case when the PPDF is estimated using Markov Chain Monte Carlo (MCMC) sampling. In this study, we develop a new approach that improves computational efficiency of Bayesian inference by constructing a surrogate system based on an adaptive sparse-grid high-order stochastic collocation (aSG-hSC) method. Unlike previous works using first-order hierarchical basis, we utilize a compactly supported higher-order hierar- chical basis to construct the surrogate system, resulting in a significant reduction in the number of computational simulations required. In addition, we use hierarchical surplus as an error indi- cator to determine adaptive sparse grids. This allows local refinement in the uncertain domain and/or anisotropic detection with respect to the random model parameters, which further improves computational efficiency. Finally, we incorporate a global optimization technique and propose an iterative algorithm for building the surrogate system for the PPDF with multiple significant modes. Once the surrogate system is determined, the PPDF can be evaluated by sampling the surrogate system directly with very little computational cost. The developed method is evaluated first using a simple analytical density function with multiple modes and then using two synthetic groundwater reactive transport models. The groundwater models represent different levels of complexity; the first example involves coupled linear reactions and the second example simulates nonlinear ura- nium surface complexation. The results show that the aSG-hSC is an effective and efficient tool for Bayesian inference in groundwater modeling in comparison with conventional MCMC sim- ulations. The computational efficiency is expected to be more beneficial to more computational expensive groundwater problems.

Zhang, Guannan [ORNL; Webster, Clayton G [ORNL; Gunzburger, Max D [ORNL

2012-09-01T23:59:59.000Z

79

The importance of parameter variances, correlations lengths, and cross-correlations in reactive transport models: key considerations for assessing the need for microscale information  

SciTech Connect

A process-oriented modeling approach is implemented to examine the importance of parameter variances, correlation lengths, and especially cross-correlations in contaminant transport predictions over large scales. It is shown that the most important consideration is the correlation between flow rates and retardation processes (e.g., sorption, matrix diffusion) in the system. lf flow rates are negatively correlated with retardation factors in systems containing multiple flow pathways, then characterizing these negative correlation(s) may have more impact on reactive transport modeling than microscale information. Such negative correlations are expected in porous-media systems where permeability is negatively correlated with clay content and rock alteration (which are usually associated with increased sorption). Likewise, negative correlations are expected in fractured rocks where permeability is positively correlated with fracture apertures, which in turn are negatively correlated with sorption and matrix diffusion. Parameter variances and correlation lengths are also shown to have important effects on reactive transport predictions, but they are less important than parameter cross-correlations. Microscale information pertaining to contaminant transport has become more readily available as characterization methods and spectroscopic instrumentation have achieved lower detection limits, greater resolution, and better precision. Obtaining detailed mechanistic insights into contaminant-rock-water interactions is becoming a routine practice in characterizing reactive transport processes in groundwater systems (almost necessary for high-profile publications). Unfortunately, a quantitative link between microscale information and flow and transport parameter distributions or cross-correlations has not yet been established. One reason for this is that quantitative microscale information is difficult to obtain in complex, heterogeneous systems. So simple systems that lack the complexity and heterogeneity of real aquifer materials are often studied. Another is that instrumentation used to obtain microscale information often probes only one variable or family of variables at a time, so linkages to other variables must be inferred by indirect means from other lines of evidence. Despite these limitations, microscale information can be useful in the development and validation of reactive transport models. For example, knowledge of mineral phases that have strong affinities for contaminants can help in the development of cross-correlations between flow and sorption parameters via characterization of permeability and mineral distributions in aquifers. Likewise, microscale information on pore structures in low-permeability zones and contaminant penetration distances into these zones from higher-permeability zones (e.g., fractures) can provide valuable constraints on the representation of diffusive mass transfer processes between flowing porosity and secondary porosity. The prioritization of obtaining microscale information in any groundwater system can be informed by modeling exercises such as those conducted for this study.

Reimus, Paul W [Los Alamos National Laboratory

2010-12-08T23:59:59.000Z

80

Reactive geothermal transport simulation to study the formation mechanism of impermeable barrier between acidic and neutral fluid zones in the Onikobe Geothermal Field, Japan  

DOE Green Energy (OSTI)

Two types of fluids are encountered in the Onikobe geothermal reservoir, one is neutral and the other is acidic (pH=3). It is hypothesized that acidic fluid might be upwelling along a fault zone and that an impermeable barrier might be present between the acidic and neutral fluid zones. We carried out reactive geothermal transport simulations using TOUGHREACT (Xu and Pruess, 1998 and 2001) to test such a conceptual model. Mn-rich smectite precipitated near the mixing front and is likely to form an impermeable barrier between regions with acidic and neutral fluids.

Todaka, Norifumi; Akasaka, Chitosi; Xu, Tianfu; Pruess, Karsten

2003-04-09T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Transportation  

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82

Transportation  

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Transportation Print banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users' Executive...

83

Transportation  

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Links Transportation and Air Quality Transportation Energy Policy Analysis Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Appliance Energy...

84

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Transportation Transportation of Depleted Uranium Materials in Support of the Depleted Uranium Hexafluoride Conversion Program Issues associated with transport of depleted UF6 cylinders and conversion products. Conversion Plan Transportation Requirements The DOE has prepared two Environmental Impact Statements (EISs) for the proposal to build and operate depleted uranium hexafluoride (UF6) conversion facilities at its Portsmouth and Paducah gaseous diffusion plant sites, pursuant to the National Environmental Policy Act (NEPA). The proposed action calls for transporting the cylinder at ETTP to Portsmouth for conversion. The transportation of depleted UF6 cylinders and of the depleted uranium conversion products following conversion was addressed in the EISs.

85

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Health Risks » Transportation Health Risks » Transportation DUF6 Health Risks line line Accidents Storage Conversion Manufacturing Disposal Transportation Transportation A discussion of health risks associated with transport of depleted UF6. Transport Regulations and Requirements In the future, it is likely that depleted uranium hexafluoride cylinders will be transported to a conversion facility. For example, it is currently anticipated that the cylinders at the ETTP Site in Oak Ridge, TN, will be transported to the Portsmouth Site, OH, for conversion. Uranium hexafluoride has been shipped safely in the United States for over 40 years by both truck and rail. Shipments of depleted UF6 would be made in accordance with all applicable transportation regulations. Shipment of depleted UF6 is regulated by the

86

Category:Geochemical Techniques | Open Energy Information  

Open Energy Info (EERE)

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87

Transportation  

Science Conference Proceedings (OSTI)

Transportation systems are an often overlooked critical infrastructure component. These systems comprise a widely diverse elements whose operation impact all aspects of society today. This chapter introduces the key transportation sectors and illustrates ...

Mark Hartong; Rajn Goel; Duminda Wijesekera

2012-01-01T23:59:59.000Z

88

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

DOE Green Energy (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 V2. The first version of TOUGHREACT was released to the public through the U.S. Department of Energy's Energy Science and Technology Software Center (ESTSC) in August 2004. It is among the most frequently requested of ESTSC's codes. The code has been widely used for studies in CO{sub 2} geological sequestration, nuclear waste isolation, geothermal energy development, environmental remediation, and increasingly for petroleum applications. Over the past several years, many new capabilities have been developed, which were incorporated into Version 2 of TOUGHREACT. Major additions and improvements in Version 2 are discussed here, and two application examples are presented: (1) long-term fate of injected CO{sub 2} in a storage reservoir and (2) biogeochemical cycling of metals in mining-impacted lake sediments.

Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.

2010-08-01T23:59:59.000Z

89

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Meier AKMeier@lbl.gov (510) 486-4740 Links Transportation and Air Quality Batteries and Fuel Cells Buildings Energy Efficiency Electricity Grid Energy Analysis Energy...

90

Upscaling of Long-Term U9VI) Desorption from Pore Scale Kinetics to Field-Scale Reactive Transport Models  

Science Conference Proceedings (OSTI)

Environmental systems exhibit a range of complexities which exist at a range of length and mass scales. Within the realm of radionuclide fate and transport, much work has been focused on understanding pore scale processes where complexity can be reduced to a simplified system. In describing larger scale behavior, the results from these simplified systems must be combined to create a theory of the whole. This process can be quite complex, and lead to models which lack transparency. The underlying assumption of this approach is that complex systems will exhibit complex behavior, requiring a complex system of equations to describe behavior. This assumption has never been tested. The goal of the experiments presented is to ask the question: Do increasingly complex systems show increasingly complex behavior? Three experimental tanks at the intermediate scale (Tank 1: 2.4m x 1.2m x 7.6cm, Tank 2: 2.4m x 0.61m x 7.6cm, Tank 3: 2.4m x 0.61m x 0.61m (LxHxW)) have been completed. These tanks were packed with various physical orientations of different particle sizes of a uranium contaminated sediment from a former uranium mill near Naturita, Colorado. Steady state water flow was induced across the tanks using constant head boundaries. Pore water was removed from within the flow domain through sampling ports/wells; effluent samples were also taken. Each sample was analyzed for a variety of analytes relating to the solubility and transport of uranium. Flow fields were characterized using inert tracers and direct measurements of pressure head. The results show that although there is a wide range of chemical variability within the flow domain of the tank, the effluent uranium behavior is simple enough to be described using a variety of conceptual models. Thus, although there is a wide range in variability caused by pore scale behaviors, these behaviors appear to be smoothed out as uranium is transported through the tank. This smoothing of uranium transport behavior transcends many of the physical and chemical heterogeneities added to the tank experiments.

Andy Miller

2009-01-25T23:59:59.000Z

91

Using laboratory flow experiments and reactive chemical transport modeling for designing waterflooding of the Agua Fria Reservoir, Poza Rica-Altamira Field, Mexico  

SciTech Connect

Waterflooding for enhanced oil recovery requires that injected waters must be chemically compatible with connate reservoir waters, in order to avoid mineral dissolution-and-precipitation cycles that could seriously degrade formation permeability and injectivity. Formation plugging is a concern especially in reservoirs with a large content of carbonates, such as calcite and dolomite, as such minerals typically react rapidly with an aqueous phase, and have strongly temperature-dependent solubility. Clay swelling can also pose problems. During a preliminary waterflooding pilot project, the Poza Rica-Altamira oil field, bordering the Gulf coast in the eastern part of Mexico, experienced injectivity loss after five months of reinjection of formation waters into well AF-847 in 1999. Acidizing with HCl restored injectivity. We report on laboratory experiments and reactive chemistry modeling studies that were undertaken in preparation for long-term waterflooding at Agua Frma. Using analogous core plugs obtained from the same reservoir interval, laboratory coreflood experiments were conducted to examine sensitivity of mineral dissolution and precipitation effects to water composition. Native reservoir water, chemically altered waters, and distilled water were used, and temporal changes in core permeability, mineral abundances and aqueous concentrations of solutes were monitored. The experiments were simulated with the multi-phase, nonisothermal reactive transport code TOUGHREACT, and reasonable to good agreement was obtained for changes in solute concentrations. Clay swelling caused an additional impact on permeability behavior during coreflood experiments, whereas the modeled permeability depends exclusively on chemical processes. TOUGHREACT was then used for reservoir-scale simulation of injecting ambient-temperature water (30 C, 86 F) into a reservoir with initial temperature of 80 C (176 F). Untreated native reservoir water was found to cause serious porosity and permeability reduction due to calcite precipitation, which is promoted by the retrograde solubility of this mineral. Using treated water that performed well in the laboratory flow experiments was found to avoid excessive precipitation, and allowed injection to proceed.

Birkle, P.; Pruess, K.; Xu, T.; Figueroa, R.A. Hernandez; Lopez, M. Diaz; Lopez, E. Contreras

2008-10-01T23:59:59.000Z

92

Injection and Reservoir Hazard Management: The Role of Injection-Induced Mechanical Deformation and Geochemical Alteration at In Salah CO2 Storage Project: Status ReportQuarter end, June 2009  

Science Conference Proceedings (OSTI)

The In Salah Gas Project (ISG), a joint venture (JV) of BP, Sonatrach, and StatoilHydro, has two fundamental goals: (1) 25-30 years of 9 bcfy natural gas production from 8 fields in the Algerian Central Sahara, and (2) successful minimization of the associated environmental footprint by capture and subsurface isolation of the excess CO{sub 2} extracted from production streams and subsurface isolation in the Krechba sandstone reservoir. The In Salah project provides an opportunity to study key physical and chemical processes in operational deployment of geological carbon sequestration. The objectives of the research are to study two components relevant to storage effectiveness and operational success at In Salah: Reactive chemistry of the brine-CO{sub 2}-reservoir-caprock-wellbore system, and the geomechanical effects of large-scale injection on crustal deformation and fault leakage hazards. Results from this work will enhance predictive capability of field performance, provide a new basis for interpretation of geophysical monitoring at In Salah, and provide additional information relevant to the creation of geological sequestration standards. The Joint Industry Partners (JIP: BP, StatoilHydro, Sonatrach) and LLNL will share data and results to achieve the objectives of the proposed work. The objective of the work performed at LLNL is to integrate LLNL core strengths in geochemistry and geomechanics to better understand and predict the fate of injected CO{sub 2} in the field. The mechanical, chemical and transport properties of the reservoir-caprock system are coupled. We are using LLNL-developed quantitative tools to assess the potential for CO{sub 2} migration/leakage caused by injection-induced deformation. The geomechanical work is focused upon fault activation, fluid induced fracturing of the caprock and permeability field evolution of the fractured reservoir. These results will be used in concert with reactive transport calculations to predict the ultimate fate of the CO{sub 2}. We will integrate laboratory and reactive transport modeling to assess CO{sub 2} plume migration and partitioning between different trapping mechanisms. Geochemical reactive transport modeling will be used to address multiphase flow (supercritical CO{sub 2} and water), CO{sub 2} dissolution, mineral sequestration, and porosity/permeability changes. The reactive transport portion of the work ultimately couples with geomechanical modeling. In particular, the distribution of the pressure perturbation induced by injection drives the geomechanical response. Subsequently, the geochemical work determines if water-rock interactions eventually enhance or suppress fractures. A key focus of this work is to establish the site specific interactions of geomechanics, reactive flow and transport. This involves building and refining models of the reservoir and overburden. The models will undergo continual refinement in response to data collected in the field and experiments performed at LLNL and elsewhere. This project commenced in FY08, with DOE funding starting in April, FY08. We have successfully initiated a cross-disciplinary study of the In Salah CO{sub 2} sequestration project and have met all FY08 and FY09 Q1, Q2 and Q3 milestones. During the reporting period, we continued to acquire and process data from the JIP to import into our own geomechanical and geochemical computational tools. The lab testing program continued using both locally formulated cements and field samples from Krechba. The geomechanical studies indicate that pore fluid pressures induced by injection will lead to significant permeability enhancement of the combination of fracture network and fault network within the reservoir in the vicinity of the injectors. We continued reactive transport calculations for CO{sub 2} rich fluids flowing through fractures. These calculations demonstrate that although porosity and permeability changes are expected in response to CO{sub 2} injection they are not anticipated to have a significant effect upon transport properties within the reservoir or c

Morris, J P; McNab, W W; Carroll, S K; Hao, Y; Foxall, W; Wagoner, J L

2009-07-30T23:59:59.000Z

93

Detailed characterization and preliminary adsorption model for materials for an intermediate-scale reactive-transport experiment  

SciTech Connect

An experiment involving migration of fluid and tracers (Li, Br, Ni) through a 6-m-high x 3-m-dia caisson Wedron 510 sand, is being carried out for Yucca Mountain Site Characterization Project. Sand`s surface chemistry of the sand was studied and a preliminary surface-complexation model of Ni adsorption formulated for transport calculations. XPS and leaching suggest that surface of the quartz sand is partially covered by thin layers of Fe-oxyhydroxide and Ca-Mg carbonate and by flakes of kaolinite. Ni adsorption by the sand is strongly pH-dependent, showing no adsorption at pH 5 and near-total adsorption at pH 7. Location of adsorption edge is independent of ionic strength and dissolved Ni concentration; it is shifted to slightly lower pH with higher pCO2 and to slightly higher pH by competition with Li. Diminished adsorption at alkiline pH with higher pCO2 implies formation of dissolved Ni-carbonato complexes. Ni adsorption edges for goethite and quartz, two components of the sand were also measured. Ni adsorption on pure quartz is only moderately pH-dependent and differs in shape and location from that of the sand, whereas Ni adsorption by goethite is strongly pH-dependent. A triple-layer surface-complexation model developed for goethite provides a good fit to the Ni-adsorption curve of the sand. Based on this model, the apparent surface area of the Fe-oxyhydroxide coating is estimated to be 560 m{sup 2}/g, compatible with its occurrence as amorphous Fe-oxyhydroxide. Potentiometric titrations on sand also differ from pure quartz and suggest that effective surface area of sand may be much greater than that measured by N{sub 2}-BET gas adsorption. Attempts to model the adsorption of bulk sand in terms of properties of pure end member components suggest that much of the sand surface is inert. Although the exact Ni adsorption mechanisms remain ambiguous, this preliminary adsorption model provides an initial set of parameters that can be used in transport calculations.

Ward, D.B.; Bryan, C.R. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Earth and Planetary Sciences; Siegel, M.D. [Sandia National Labs., Albuquerque, NM (United States)

1994-12-31T23:59:59.000Z

94

Modeling and Simulation of Pore Scale Multiphase Fluid Flow and Reactive Transport in Fractured and Porous Media  

Science Conference Proceedings (OSTI)

In the subsurface fluids play a critical role by transporting dissolved minerals, colloids and contaminants (sometimes over long distances), by mediating dissolution and precipitation processes and enabling chemical transformations in solution and at mineral surfaces. Although the complex geometries of fracture apertures, fracture networks and pore spaces may make it difficult to accurately predict fluid flow in saturated (single-phase) subsurface systems, well developed methods are available. The simulation of multiphase fluid flow in the subsurface is much more challenging because of the large density and/or viscosity ratios found in important applications (water/air in the vadose zone, water/oil, water/gas, gas/oil and water/oil/gas in oil reservoirs, water/air/non-aqueous phase liquids (NAPL) in contaminated vadose zone systems and gas/molten rock in volcanic systems, for example). In addition, the complex behavior of fluid-fluid-solid contact lines, and its impact on dynamic contact angles, must also be taken into account, and coupled with the fluid flow. Pore network models and simple statistical physics based models such as the invasion percolation and diffusion-limited aggregation models have been used quite extensively. However, these models for multiphase fluid flow are based on simplified models for pore space geometries and simplified physics. Other methods such a lattice Boltzmann and lattice gas models, molecular dynamics, Monte Carlo methods, and particle methods such as dissipative particle dynamics and smoothed particle hydrodynamics are based more firmly on first principles, and they do not require simplified pore and/or fracture geometries. However, they are less (in some cases very much less) computationally efficient that pore network and statistical physics models. Recently a combination of continuum computation fluid dynamics, fluid-fluid interface tracking or capturing and simple models for the dependence of contact angles on fluid velocity at the contact line has been used to simulate multiphase fluid flow in fracture apertures, fracture networks and pore spaces. Fundamental conservation principles - conservation of momentum, and conservation of mass (or conservation of volume for incompressible fluids) and conservation of energy, as well as symmetries (Galilean invariance and isotropy) are central to the physics of fluids and the models used to simulate them. In molecular and mesoscale models observance of these conservation principles and symmetries at the microscopic level leads to macroscopic fluid dynamics that can be represented by the Navier Stokes equation. The remarkable fact that the flow of all simpe fluids, irrespective of their chemical nature, can be described by the Navier-Stokes equation is a result of these conservation principles and symmetries acting on the molecular level.

Paul Meakin; Alexandre Tartakovsky

2009-07-01T23:59:59.000Z

95

Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center  

Science Conference Proceedings (OSTI)

This report summarizes research conducted in conjunction with a project entitled “Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center”, which was funded through the Integrative Studies Element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. William Burgos (The Pennsylvania State University) was the overall PI/PD for the project, which included Brian Dempsey (Penn State), Gour-Tsyh (George) Yeh (Central Florida University), and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The project focused on development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. The work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and was directly aligned with the Scheibe et al. ORNL FRC Field Project at Area 2.

Burgos, W.D.

2009-09-02T23:59:59.000Z

96

Geochemical engineering design tools for uranium in situ recovery : the HYDROGEOCHEM codes.  

SciTech Connect

Geochemical Engineering Design (GED) is based on applications of the principles and various computer models that describe the biogeochemistry and physics of removal of contaminants from water by adsorption, precipitation and filtration. It can be used to optimize or evaluate the efficiency of all phases of in situ recovery (ISR). The primary tools of GED are reactive transport models; this talk describes the potential application of the HYDROGEOCHEM family of codes to ISR. The codes can describe a complete suite of equilibrium or kinetic aqueous complexation, adsorption-desorption, precipitation-dissolution, redox, and acid-base reactions in variably saturated media with density-dependent fluid flow. Applications to ISR are illustrated with simulations of (1) the effectiveness of a reactive barrier to prevent off-site uranium migration and (2) evaluation of the effect of sorption hysteresis on natural attenuation. In the first example, it can be seen that the apparent effectiveness of the barrier depends on monitoring location and that it changes over time. This is due to changes in pH, saturation of sorption sites, as well as the geometry of the flow field. The second simulation shows how sorption hysteresis leads to observable attenuation of a uranium contamination plume. Different sorption mechanisms including fast (or reversible), slow, and irreversible sorption were simulated. The migration of the dissolved and total uranium plumes for the different cases are compared and the simulations show that when 50-100% of the sites have slow desorption rates, the center of mass of the dissolved uranium plume begins to move upstream. This would correspond to the case in which the plume boundaries begin to shrink as required for demonstration of natural attenuation.

Siegel, Malcolm Dean; Li, Ming-Hsu (National Central University, Jhongli City, Taiwan); Yeh, Gour-Tsyh (University of Central Florida, Orlando, FL)

2010-11-01T23:59:59.000Z

97

Proceedings of the workshop on geochemical modeling  

SciTech Connect

The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices.

Not Available

1986-01-01T23:59:59.000Z

98

A geochemical expert system prototype using object-oriented knowledge representation and a production rule system  

Science Conference Proceedings (OSTI)

Keywords: MINEQL, artificial intelligence, expert systems, geochemical expert system, geochemical modeling, geochemistry

Forrest M. Hoffman; Vijay S. Tripathi

1993-01-01T23:59:59.000Z

99

Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Due to limited parking, all visitors are strongly encouraged to: Due to limited parking, all visitors are strongly encouraged to: 1) car-pool, 2) take the Lab's special conference shuttle service, or 3) take the regular off-site shuttle. If you choose to use the regular off-site shuttle bus, you will need an authorized bus pass, which can be obtained by contacting Eric Essman in advance. Transportation & Visitor Information Location and Directions to the Lab: Lawrence Berkeley National Laboratory is located in Berkeley, on the hillside directly above the campus of University of California at Berkeley. The address is One Cyclotron Road, Berkeley, California 94720. For comprehensive directions to the lab, please refer to: http://www.lbl.gov/Workplace/Transportation.html Maps and Parking Information: On Thursday and Friday, a limited number (15) of barricaded reserved parking spaces will be available for NON-LBNL Staff SNAP Collaboration Meeting participants in parking lot K1, in front of building 54 (cafeteria). On Saturday, plenty of parking spaces will be available everywhere, as it is a non-work day.

100

Characterization of materials for a reactive transport model validation experiment: Interim report on the caisson experiment. Yucca Mountain Site Characterization Project  

SciTech Connect

Models used in performance assessment and site characterization activities related to nuclear waste disposal rely on simplified representations of solute/rock interactions, hydrologic flow field and the material properties of the rock layers surrounding the repository. A crucial element in the design of these models is the validity of these simplifying assumptions. An intermediate-scale experiment is being carried out at the Experimental Engineered Test Facility at Los Alamos Laboratory by the Los Alamos and Sandia National Laboratories to develop a strategy to validate key geochemical and hydrological assumptions in performance assessment models used by the Yucca Mountain Site Characterization Project.

Siegel, M.D.; Cheng, W.C. [Sandia National Labs., Albuquerque, NM (United States); Ward, D.B.; Bryan, C.R. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Earth and Planetary Sciences

1995-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
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101

HYDROBIOGEOCHEM: A coupled model of HYDROlogic transport and mixed BIOGEOCHEMical kinetic/equilibrium reactions in saturated-unsaturated media  

Science Conference Proceedings (OSTI)

The computer program HYDROBIOGEOCHEM is a coupled model of HYDROlogic transport and BIOGEOCHEMical kinetic and/or equilibrium reactions in saturated/unsaturated media. HYDROBIOGEOCHEM iteratively solves the two-dimensional transport equations and the ordinary differential and algebraic equations of mixed biogeochemical reactions. The transport equations are solved for all aqueous chemical components and kinetically controlled aqueous species. HYDROBIOGEOCHEM is designed for generic application to reactive transport problems affected by both microbiological and geochemical reactions in subsurface media. Input to the program includes the geometry of the system, the spatial distribution of finite elements and nodes, the properties of the media, the potential chemical and microbial reactions, and the initial and boundary conditions. Output includes the spatial distribution of chemical and microbial concentrations as a function of time and space, and the chemical speciation at user-specified nodes.

Yeh, G.T.; Salvage, K.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering] [Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering; Gwo, J.P. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States); Zachara, J.M.; Szecsody, J.E. [Pacific Northwest National Lab., Richland, WA (United States)] [Pacific Northwest National Lab., Richland, WA (United States)

1998-07-01T23:59:59.000Z

102

Progress Report, December 2010: Improved Site Characterization And Storage Prediction Through Stochastic Inversion Of Time-Lapse Geophysical And Geochemical Data  

Science Conference Proceedings (OSTI)

Over the last project six months, our project activities have concentrated on three areas: (1) performing a stochastic inversion of pattern 16 seismic data to deduce reservoir permeability, (2) development of the geochemical inversion strategy and implementation of associated software, and (3) completing the software implementation of TProGS and the geostatistical analysis that provides the information needed when using the software to produce realizations of the Midale reservoir. The report partially the following deliverables: D2: Model development: MCMC tool (synthetic fluid chemistry data); deliverable completed. D4: Model development/verification: MCMC tool (TProGS, field seismic/chemistry data) work product; deliverable requirements partially fulfilled. D5: Field-based single-pattern simulations work product; deliverable requirements partially fulfilled. When completed, our completed stochastic inversion tool will explicitly integrate reactive transport modeling, facies-based geostatistical methods, and a novel stochastic inversion technique to optimize agreement between observed and predicted storage performance. Such optimization will be accomplished through stepwise refinement of: (1) the reservoir model - principally its permeability magnitude and heterogeneity - and (2) geochemical parameters - primarily key mineral volume fractions and kinetic data. We anticipate that these refinements will facilitate significantly improved history matching and forward modeling of CO{sub 2} storage. Our tool uses the Markov Chain Monte Carlo (MCMC) methodology. Deliverable D1, previously submitted as a report titled ''Development of a Stochastic Inversion Tool To Optimize Agreement Between The Observed And Predicted Seismic Response To CO{sub 2} Injection/Migration in the Weyburn-Midale Project'' (Ramirez et al., 2009), described the stochastic inversion approach that will identify reservoir models that optimize agreement between the observed and predicted seismic response. The software that implements this approach has been completed, tested, and used to process seismic data from pattern 16. A previously submitted report titled ''Model verification: synthetic single pattern simulations using seismic reflection data'', Ramirez et al. 2010, partially fulfilled deliverable D3 by summarizing verification activities that evaluate the performance of the seismic software and its ability to recover reservoir model permeabilities using synthetic seismic reflection data. A future progress report will similarly describe summarizing verification activities of the geochemical inversion software, thereby completing deliverable D3. This document includes a chapter that shows and discusses permeability models produced by seismic inversion that used seismic data from pattern 16 in Phase 1A. It partially fulfills deliverable D5: Field-based single-pattern simulations work product. The D5 work product is supposed to summarize the results of applying NUFT/MCMC to refine the reservoir model and geochemical parameters by optimizing observation/prediction agreement for the seismic/geochemical response to CO{sub 2} injection/migration within a single pattern of Phase 1A/1B. A future progress report will show inversion results for the same pattern using geochemical data, thereby completing deliverable D5. This document also contains a chapter that fulfills deliverable D2: Model development: MCMC tool (synthetic fluid chemistry data). The chapter will summarize model development activities required to facilitate application of NUFT/MCMC to optimize agreement between the observed and predicted geochemical response to CO{sub 2} injection/migration. Lastly, this document also contains a chapter that partially fulfills deliverable D4: Model development/verification: MCMC tool (TProGS, field seismic/chemistry data) work product. This work product is supposed to summarize model development activities required for (1) application of TProGS to Weyburn, (2) use of TProGS within the MCMC tool, and (3) application of the MCMC tool to address field seismic and g

Ramirez, A; Mcnab, W; Carle, S; Hao, Y; White, D; Johnson, J

2010-12-17T23:59:59.000Z

103

Modeling Arsenic Fate and Transport in Groundwater  

Science Conference Proceedings (OSTI)

The fate of arsenic in the environment depends on a variety of geochemical factors, including pH, oxidation and reduction potential, and the presence of competing solutes such as phosphates. Methods of predicting arsenic fate and transport are evolving to incorporate sophisticated geochemical simulations. While contaminant transport codes that utilize adsorption isotherm equations may be inadequate for arsenic prediction in certain cases, they may be very powerful tools in others. This report describes t...

2006-08-16T23:59:59.000Z

104

TRANSPORTATION TRANSPORTATION  

E-Print Network (OSTI)

TEXASTRANS TEXAS TRANSPORTATION HALL HONOR OF HALL HONOR OF TEXASTRAN HALL HONOR OF TEXASTRAN HALL HONOR OF Inductees #12;2 TEXAS TRANSPORTATION HALL HONOR OF L NOR OF Texas is recognized as having one of the finest multimodal transportation systems in the world. The existence of this system has been key

105

Holocene deposition in Northwest Providence Channel, Bahamas: a geochemical approach  

SciTech Connect

The origins and depositional history of Holocene sediment in Northwest Providence Channel, Bahamas (NWPC) have been determined using geochemical measurements coupled with textural data, petrographic examination, and scanning electron microscopy. Most of the channel is 200 to 2000 m deep, and nearly 100% of the sediment is calcium carbonate. Shallow water platform sources contribute 75-90% of the Holocene sediment in NWPC. Bank derived sand is most abundant near the platforms (nearly 100%) and is concentrically distributed around a central area of abundant non-platform sand. Bank-derived mud (<62 ..mu..m) accounts for more than 80% of the mud fraction in NWPC. The coarse silt (62-16 ..mu..m), fine silt (16-4 ..mu..m) and clay (< 4 ..mu..m) fractions from LLB (Bight of Abaco) are geochemically distinct from the mud fractions of Great Bahama Bank (GBB). Their distributions in NWPC demonstrate that both platforms are significant sediment contributors to NWPC. The observed sediment distribution clearly indicates that significant off bank transport occurs. With regard to sediment transport, no windward or leeward effects are observed in Holocene sediment deposition. Gravity flow processes are not significant to Holocene deposition. 80% of the present sedimentation rate results from the banktop flooding and confirms that 75%-90% of the Holocene sediment is derived from platform sources. The C-14 dated Holocene sediment layer is approximately 50 cm thick, and its transition with the Pleistocene occurs over a vertical interval of less than 20 cm as a result of mixing by benthonic organisms. This Holocene sediment layer should remain intact to permanently record this banktop episode, and should have a different diagenetic future from the underlying stable (calcite-rich) sediment.

Boardman, M.R.

1978-01-01T23:59:59.000Z

106

Using laboratory flow experiments and reactive chemical transport modeling for designing waterflooding of the Agua Fria Reservoir, Poza Rica-Altamira Field, Mexico  

E-Print Network (OSTI)

transport modeling of injection well scaling and acidizingrecovery program. U S A M Injection well Observation wellFig. 1—Location of 5 injection wells and 18 monitoring wells

Birkle, P.

2009-01-01T23:59:59.000Z

107

NUREG/CR-6870 Consideration of Geochemical  

E-Print Network (OSTI)

mining and milling of uranium ore. Nonetheless, the use of leaching fluids to mine uranium contaminatesNUREG/CR-6870 Consideration of Geochemical Issues in Groundwater Restoration at Uranium In in Groundwater Restoration at Uranium In-Situ Leach Mining Facilities Manuscript Completed: December 2006 Date

108

Geochemical engineering problem identification and program description. Final report  

SciTech Connect

The Geochemical Engineering Program has as its goal the improvement of geochemical fluid management techniques. This document presents the strategy and status of the Geochemical Engineering Program. The magnitude and scope of geochemical-related problems constraining geothermal industry productivity are described. The goals and objectives of the DGE Geochemical Engineering Program are defined. The rationale and strategy of the program are described. The structure, priorities, funding, and management of specific elements within the program are delineated, and the status of the overall program is presented.

Crane, C.H.; Kenkeremath, D.C.

1981-05-01T23:59:59.000Z

109

Geochemical Implications of Gas Leakage Associated with Geologic CO2 Storage - A Qualitative Review  

SciTech Connect

Leakage from deep storage reservoirs is considered the major risk factor associated with geologic sequestration of CO2. Different schools of thought exist concerning the potential implications of such leakage for near-surface environments. We reviewed the current literature on how CO2 leakage (from storage reservoirs) would likely impact the geochemistry of overlying potable aquifers. Results from experimental and modeling studies point to the potential for both beneficial (e.g. contaminant immobilization) and deleterious (e.g. contaminant mobilization) consequences of CO2 intrusion into potable groundwater. However, there are significant discrepancies between studies particularly concerning, what contaminants are of concern and the geochemical processes involved. These discrepancies reflected the lack of a consensus on CO2-induced changes in subsurface geochemical processes and subsequent effects on groundwater chemistry. The development of consistent experimental protocols and the identification of pertinent factors driving CO2-induced geochemical changes in the subsurface were identified as key research needs. Geochemical modeling was used to systematically highlight why a standardization of experimental protocols and the consideration of experimental factors such as gas leakage rates, redox status and the influence of co-transported gases are pertinent. The role of analog studies, reactions occurring in the vadose zone, and the influence of organic contaminants are also discussed.

Harvey, Omar R.; Qafoku, Nikolla; Cantrell, Kirk J.; Lee, Gie Hyeon; Amonette, James E.; Brown, Christopher F.

2013-01-01T23:59:59.000Z

110

Elucidating geochemical response of shallow heterogeneous aquifers to CO2 leakage using high-performance computing: Implications for monitoring of CO2 sequestration  

SciTech Connect

Predicting and quantifying impacts of potential carbon dioxide (CO2) leakage into shallow aquifers that overlie geologic CO2 storage formations is an important part of developing reliable carbon storage techniques. Leakage of CO2 through fractures, faults or faulty wellbores can reduce groundwater pH, inducing geochemical reactions that release solutes into the groundwater and pose a risk of degrading groundwater quality. In order to help quantify this risk, predictions of metal concentrations are needed during geologic storage of CO2. Here, we present regional-scale reactive transport simulations, at relatively fine-scale, of CO2 leakage into shallow aquifers run on the PFLOTRAN platform using high-performance computing. Multiple realizations of heterogeneous permeability distributions were generated using standard geostatistical methods. Increased statistical anisotropy of the permeability field resulted in more lateral and vertical spreading of the plume of impacted water, leading to increased Pb2+ (lead) concentrations and lower pH at a well down gradient of the CO2 leak. Pb2+ concentrations were higher in simulations where calcite was the source of Pb2+ compared to galena. The low solubility of galena effectively buffered the Pb2+ concentrations as galena reached saturation under reducing conditions along the flow path. In all cases, Pb2+ concentrations remained below the maximum contaminant level set by the EPA. Results from this study, compared to natural variability observed in aquifers, suggest that bicarbonate (HCO3) concentrations may be a better geochemical indicator of a CO2 leak under the conditions simulated here.

Navarre-Sitchler, Alexis K.; Maxwell, Reed M.; Siirila, Erica R.; Hammond, Glenn E.; Lichtner, Peter C.

2013-03-01T23:59:59.000Z

111

Experimental Geochemical Studies Relevant to Carbon Sequestration  

NLE Websites -- All DOE Office Websites (Extended Search)

Geochemical Studies Relevant to Geochemical Studies Relevant to Carbon Sequestration James G. Blencoe (blencoejg@ornl.gov; 865-574-7041) David R. Cole (coledr@ornl.gov; 865-574-5473) Juske Horita (horitaj@ornl.gov; 865-576-2750) Geochemistry Group Chemical and Analytical Sciences Division Oak Ridge National Laboratory P.O. Box 2008, Building 4500-S Oak Ridge, TN 37831-6110 Gerilynn R. Moline (molinegr@ornl.gov; 865-576-5134) Environmental Sciences Division Oak Ridge National Laboratory P.O. Box 2008, Building 1505 Oak Ridge, TN 37831-6038 Introduction Evidence is mounting that rising levels of atmospheric CO 2 will have profound effects on future global climates (1-2) . Consequently, many experts agree that technologies are needed to slow, and ultimately stop, further buildup (3-5) . One of the strategies proposed to achieve this aim

112

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive...  

NLE Websites -- All DOE Office Websites (Extended Search)

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive Transport Processes Associated with Carbon Sequestration PI Name: David Trebotich Institution: Lawrence Berkeley...

113

Category:Geochemical Data Analysis | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Category Edit History Facebook icon Twitter icon » Category:Geochemical Data Analysis Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Geochemical Data Analysis page? For detailed information on exploration techniques, click here. Category:Geochemical Data Analysis Add.png Add a new Geochemical Data Analysis Technique Pages in category "Geochemical Data Analysis" The following 3 pages are in this category, out of 3 total. G Geothermometry T Thermal Ion Dispersion Thermochronometry Retrieved from "http://en.openei.org/w/index.php?title=Category:Geochemical_Data_Analysis&oldid=689825"

114

Temporal Geochemical Variations In Volatile Emissions From Mount...  

Open Energy Info (EERE)

Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Temporal...

115

Trace Element Geochemical Zoning in the Roosevelt Hot Springs...  

Open Energy Info (EERE)

Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah Abstract Chemical interaction of thermal brines with reservoir rock in the Roosevelt Hot Springs...

116

Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site  

SciTech Connect

The major objectives of the proposed study were to: 1.) determine the leaching characteristics of hexavalent chromium [Cr(VI)] from contaminated sediments collected from 100 Area spill sites; 2.) elucidate possible Cr(VI) mineral and/or chemical associations that may be responsible for Cr(VI) retention in the Hanford Site 100 Areas through the use of i.) macroscopic leaching studies and ii.) microscale characterization of contaminated sediments; and 3.) provide information to construct a conceptual model of Cr(VI) geochemistry in the Hanford 100 Area vadose zone. In addressing these objectives, additional benefits accrued were: (1) a fuller understanding of Cr(VI) entrained in the vadose zone that will that can be utilized in modeling potential Cr(VI) source terms, and (2) accelerating the Columbia River 100 Area corridor cleanup by providing valuable information to develop remedial action based on a fundamental understanding of Cr(VI) vadose zone geochemistry. A series of macroscopic column experiments were conducted with contaminated and uncontaminated sediments to study Cr(VI) desorption patterns in aged and freshly contaminated sediments, evaluate the transport characteristics of dichromate liquid retrieved from old pipelines of the 100 Area; and estimate the effect of strongly reducing liquid on the reduction and transport of Cr(VI). Column experiments used the < 2 mm fraction of the sediment samples and simulated Hanford groundwater solution. Periodic stop-flow events were applied to evaluate the change in elemental concentration during time periods of no flow and greater fluid residence time. The results were fit using a two-site, one dimensional reactive transport model. Sediments were characterized for the spatial and mineralogical associations of the contamination using an array of microscale techniques such as XRD, SEM, EDS, XPS, XMP, and XANES. The following are important conclusions and implications. Results from column experiments indicated that most of contaminant Cr travels fast through the sediments and appears as Cr(VI) in the effluents. The significance of this for groundwater concentrations would, however, depend on the mass flux of recharge to the water table. adsorption of Cr(VI) to sediments from spiked Cr(VI) solution is low; calculated retardation coefficients are close to one. Calcium polysulfide solutions readily reduced Cr(VI) to Cr(III) in column experiments. However a significant amount of the Cr(VI) was mobilized ahead of the polysulfide solution front. This has significant implications for in-situ reductive remediation techniques. The experiments suggest that it would be difficult to design a remedial measure using infiltration of liquid phase reductants without increasing transport of Cr(VI) toward the water table. The microscopic characterization results are consistent with the column studies. Cr(VI) is found as ubiquitous coatings on sediment grain surfaces. Small, higher concentration, chromium sites are associated with secondary clay mineral inclusions, with occasional barium chromate minerals, and reduced to Cr(III) in association with iron oxides that are most likely magnetite primary minerals. Within the restricted access domains of sediment matrix, ferrous iron could also diffuse from in situ, high-surface-area minerals to cause the reductive immobilization of chromate. This process may be favored at microscale geochemical zones where ferrous iron could be supplied. Once nucleated, micrometer-scale precipitates are favored as growing locales for further accumulation, causing the formation of discrete zones of Cr(III).

Dresel, P. Evan; Qafoku, Nikolla; McKinley, James P.; Fruchter, Jonathan S.; Ainsworth, Calvin C.; Liu, Chongxuan; Ilton, Eugene S.; Phillips, J. L.

2008-07-16T23:59:59.000Z

117

DNA-based methods of geochemical prospecting  

Science Conference Proceedings (OSTI)

The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

Ashby, Matthew (Mill Valley, CA)

2011-12-06T23:59:59.000Z

118

Effect of small-scale fractures on flow and transport processes at Yucca Mountain, Nevada  

E-Print Network (OSTI)

a significant impact on radionuclide transport in the UZresults for tracer/radionuclide transport are presented witha reactive (neptunium) radionuclide. Transport simulation is

Wu, Yu-Shu; Liu, H.H.; Bodvarsson, G.S.

2002-01-01T23:59:59.000Z

119

Plutonium Transport Through Lysimeters Exposed to Natural Weather Conditions for Two to Twelve Years  

Science Conference Proceedings (OSTI)

One of the most important factors influencing the subsurface transport of plutonium (Pu) is its oxidation state. Under similar geochemical conditions (e.g., groundwater pH) the mobility of reduced Pu, Pu(IV), is two to three orders of magnitude lower than that of oxidized Pu, Pu(V) and Pu(VI). However, due to a poor understanding of Pu oxidation state transformations, transport models typically employ conservative assumptions which can lead to overly conservative and costly decisions. The objective of this study was to develop a conceptual geochemical transport model to describe Pu mobility through 52-L lysimeters established in 1980. The lysimeters contained E-Area sediment and various forms of well-characterized Pu sources of known oxidation state and were exposed to natural SRS weather conditions for up to 11 years. For this study, archived core sediments from the lysimeters were retrieved and Pu concentrations in depth-discrete samples were measured and then transport of Pu was modeled using a coupled reactive transport model. The geochemical conceptual model and input values included in the transport code were based on laboratory experiments. The single most important finding from this work was regardless of the Pu oxidation state added to SRS sediments, it quickly converted to the less mobile Pu(IV) form. In conclusion, it is expected that Pu will exist primarily in the SRS subsurface environment in the relatively less mobile Pu(IV) form, irrespective of the oxidation state that it first enters the ground. The lysimeter results provide important long-term data that support the removal of important overly conservative approaches presently used to calculate risk and performance assessment associated with groundwater Pu. These findings do not contradict previous Pu modeling efforts, including the E-Area Low-Level Waste Performance Assessment or the Special Analysis on Pu disposal in SRS trenches. Instead, the results from this work could be used in future calculations to improve accuracy and reduce uncertainty and conservatism.

Kaplan, D.I.

2003-10-20T23:59:59.000Z

120

GEOCHEMICAL CONTROLS ON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS  

Science Conference Proceedings (OSTI)

Proton nuclear magnetic resonance (NMR) is used in the Earth Sciences as a means of obtaining information about the molecular-scale environment of fluids in porous geological materials. Laboratory experiments were conducted to advance our fundamental understanding of the link between the NMR response and the geochemical properties of geological materials. In the first part of this research project, we studied the impact of both the surface-area-to-volume ratio (S/V) of the pore space and the surface relaxivity on the NMR response of fluids in sand-clay mixtures. This study highlighted the way in which these two parameters control our ability to use NMR measurements to detect and quantify fluid saturation in multiphase saturated systems. The second part of the project was designed to explore the way in which the mineralogic form of iron, as opposed to simply the concentration of iron, affects the surface relaxation rate and, more generally, the NMR response of porous materials. We found that the magnitude of the surface relaxation rate was different for the various iron-oxide minerals because of changes in both the surface-area-to-volume ratio of the pore space, and the surface relaxivity. Of particular significance from this study was the finding of an anomalously large surface relaxivity of magnetite compared to that of the other iron minerals. Differences in the NMR response of iron minerals were seen in column experiments during the reaction of ferrihydrite-coated quartz sand with aqueous Fe(II) solutions to form goethite, lepidocrocite and magnetite; indicating the potential use of NMR as a means of monitoring geochemical reactions. The final part of the research project investigated the impact of heterogeneity, at the pore-scale, on the NMR response. This work highlighted the way in which the geochemistry, by controlling the surface relaxivity, has a significant impact on the link between NMR data and the microgeometry of the pore space.

Rosemary Knight

2008-08-25T23:59:59.000Z

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121

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

Energy.gov (U.S. Department of Energy (DOE))

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

122

Geochemical Data Package for Performance Assessment Calculations Related to the Savannah River Site  

Science Conference Proceedings (OSTI)

The Savannah River Site disposes of certain types of radioactive waste within subsurface-engineered facilities. One of the tools used to establish the capacity of a given site to safely store radioactive waste (i.e., that a site does not exceed its Waste Acceptance Criteria) is the Performance Assessment (PA). The objective of this document is to provide the geochemical values for the PA calculations. This work is being conducted as part of the on-going maintenance program that permits the PA to periodically update existing calculations when new data becomes available. Because application of values without full understanding of their original purpose may lead to misuse, this document also provides the geochemical conceptual model, approach used for selecting the values, the justification for selecting data, and the assumptions made to assure that the conceptual and numerical geochemical models are reasonably conservative (i.e., reflect conditions that will tend to predict the maximum risk to the hypothetical recipient). The geochemical parameters describe transport processes for 38 elements (>90 radioisotopes) potentially occurring within eight disposal units (Slit Trenches, Engineered Trenches, Low Activity Waste (LAW) Vault, Intermediate Level (ILV) Vaults, TRU-Pad-1, Naval Reactor Waste Pads, Components-in-Grout Trenches, and Saltstone Facility). This work builds upon well-documented work from previous PA calculations (McDowell-Boyer et al. 2000). The new geochemical concepts introduced in this data package are: (1) In the past, solubility products were used only in a few conditions (element existing in a specific environmental setting). This has been expanded to >100 conditions. (2) Radionuclide chemistry in cementitious environments is described through the use of both the Kd and apparent solubility concentration limit. Furthermore, the solid phase is assumed to age during the assessment period (thousands of years), resulting in three main types of controlling solid phases, each possessing a unique set of radionuclide sorption parameters (Kd and solubility concentration limit). (3) A large amount of recent site-specific sorption research has been conducted since the last PA (McDowell-Boyer et al. 2000). These new data have replaced previous Kd values derived from literature values, thus reducing uncertainty and improving accuracy. Finally, because this document will be used by future PA calculations and external acceptance of the document will eventually be required, this document was extensively reviewed. The review process, including the internal review, site review, and external review process is described.

Kaplan, D

2006-02-28T23:59:59.000Z

123

A Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal  

Open Energy Info (EERE)

Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal System, Danakil Depression, Eritrea Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Geochemical Reconnaissance Of The Alid Volcaniccenter And Geothermal System, Danakil Depression, Eritrea Details Activities (0) Areas (0) Regions (0) Abstract: Geological and geochemical studies indicate that a high-temperature geothermalsystem underlies the Alid volcanic center in the northern Danakil depression of Eritrea Alid is avery late-Pleistocene structural dome formed by shallow intrusion of rhyolitic magma some of which vented as lavas and pyroclastic flows Fumaroles and boiling pools distributed widelyover an area of ~10 km2 on the northern half of Alid suggest that an activehydrothermal system underlies much of that part of

124

Geochemical Sampling of Thermal Waters in Nevada | Open Energy Information  

Open Energy Info (EERE)

Geochemical Sampling of Thermal Waters in Nevada Geochemical Sampling of Thermal Waters in Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Geochemical Sampling of Thermal Waters in Nevada Abstract There are 1000 thermal springs in Nevada for which a location is known, but for which there are no available temperature (or chemical) measurements. Although many of these sites are within known geothermal areas and are located near springs for which temperature and/or geochemical data are available for one of the springs, many of these sites are not so located and require evaluation before the geothermal potential of the area can be assessed. In order to begin filling in data gaps, water sampling commenced in 2002 when over 70 analyses were obtained from springs with previously

125

Factors Controlling The Geochemical Evolution Of Fumarolic Encrustations,  

Open Energy Info (EERE)

Controlling The Geochemical Evolution Of Fumarolic Encrustations, Controlling The Geochemical Evolution Of Fumarolic Encrustations, Valley Of Ten Thousand Smokes, Alaska Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Factors Controlling The Geochemical Evolution Of Fumarolic Encrustations, Valley Of Ten Thousand Smokes, Alaska Details Activities (3) Areas (1) Regions (0) Abstract: Factor and canonical correlation analysis of geochemical data from eight fossil fumaroles suggest that six major factors controlled the formation and evolution of fumarolic encrustations on the 1912 ash-flow sheet in the Valley of Ten Thousand Smokes (VTTS). The six-factor solution model explains a large proportion (low of 74% for Ni to high of 99% for Si) of the individual element data variance. Although the primary fumarolic

126

Molecular geomicrobiology: genes and geochemical cycling Jennifer Macalady 1  

E-Print Network (OSTI)

Frontiers Molecular geomicrobiology: genes and geochemical cycling Jennifer Macalady 1 , Jillian F occurs. Yet, the field of molecular geomicrobiology remains in its infancy. In the foreseeable future, merging of modern biogeochemistry with molecularly resolved ecological studies will inspire

Macalady, Jenn

127

GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY  

SciTech Connect

From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin chemistry and variability included: (1) the nature or chemistry of the waste streams, (2) the open system of the basins, and (3) duration of discharge of the waste stream types. Mixing models of the archetype waste streams indicated that the overall basin system would likely remain acidic much of the time. Only an extended periods of predominantly alkaline waste discharge (e.g., >70% alkaline waste) would dramatically alter the average pH of wastewater entering the basins. Short term and long term variability were evaluated by performing multiple stepwise modeling runs to calculate the oscillation of bulk chemistry in the basins in response to short term variations in waste stream chemistry. Short term (1/2 month and 1 month) oscillations in the waste stream types only affected the chemistry in Basin 1; little variation was observed in Basin 2 and 3. As the largest basin, Basin 3 is considered the primary source to the groundwater. Modeling showed that the fluctuation in chemistry of the waste streams is not directly representative of the source term to the groundwater (i.e. Basin 3). The sequence of receiving basins and the large volume of water in Basin 3 'smooth' or nullify the short term variability in waste stream composition. As part of this study, a technically-based 'charge-balanced' nominal source term chemistry was developed for Basin 3 for a narrow range of pH (2.7 to 3.4). An example is also provided of how these data could be used to quantify uncertainty over the long term variations in waste stream chemistry and hence, Basin 3 chemistry.

Millings, M.; Denham, M.; Looney, B.

2012-05-08T23:59:59.000Z

128

System for reactivating catalysts  

DOE Patents (OSTI)

A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)

2010-03-02T23:59:59.000Z

129

Spatial And Temporal Geochemical Trends In The Hydrothermal System Of  

Open Energy Info (EERE)

Spatial And Temporal Geochemical Trends In The Hydrothermal System Of Spatial And Temporal Geochemical Trends In The Hydrothermal System Of Yellowstone National Park- Inferences From River Solute Fluxes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Spatial And Temporal Geochemical Trends In The Hydrothermal System Of Yellowstone National Park- Inferences From River Solute Fluxes Details Activities (2) Areas (1) Regions (0) Abstract: We present and analyze a chemical dataset that includes the concentrations and fluxes of HCO3-, SO42-, Cl-, and F- in the major rivers draining Yellowstone National Park (YNP) for the 2002-2004 water years (1 October 2001 - 30 September 2004). The total (molar) flux in all rivers decreases in the following order, HCO3- > Cl- > SO42- > F-, but each river is characterized by a distinct chemical composition, implying large-scale

130

A Reconnaissance Geochemical Study Of La Primavera Geothermal Area,  

Open Energy Info (EERE)

Reconnaissance Geochemical Study Of La Primavera Geothermal Area, Reconnaissance Geochemical Study Of La Primavera Geothermal Area, Jalisco, Mexico Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Reconnaissance Geochemical Study Of La Primavera Geothermal Area, Jalisco, Mexico Details Activities (0) Areas (0) Regions (0) Abstract: The Sierra La Primavera, a late Pleistocene rhyolitic caldera complex in Jalisco, Mexico, contains fumaroles and large-discharge 65°C hot springs that are associated with faults related to caldera collapse and to later magma insurgence. The nearly-neutral, sodium bicarbonate, hot springs occur at low elevations at the margins of the complex, whereas the water-rich fumaroles are high and central. The Comision Federal de Electricidad de Mexico (CFE) has recently drilled two deep holes at the

131

Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal  

Open Energy Info (EERE)

Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Areas Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Hg Anomalies In Soils- A Geochemical Exploration Method For Geothermal Areas Details Activities (5) Areas (5) Regions (0) Abstract: Hg contents of soils in geothermal areas in the western U.S. were measured and a three-fold distribution was observed: peak, aureole and background. Peak values (up to several 100 ppm Hg) occur in fumaroles of vapour-dominated systems, around hot springs, and in zones overlying steeply dipping, hot-water aquifers. Aureoic values (up to several 100 ppb Hg) are found in zones surrounding the peak areas and delineate areas with shallow geothermal convection. Background values vary between 7 and 40 ppb

132

A Geochemical Model Of The Platanares Geothermal System, Honduras | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » A Geochemical Model Of The Platanares Geothermal System, Honduras Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Geochemical Model Of The Platanares Geothermal System, Honduras Details Activities (0) Areas (0) Regions (0) Abstract: Results of exploration drilling combined with results of geologic, geophysical, and hydrogeochemical investigations have been used to construct a geochemical model of the Platanares geothermal system, Honduras. Three coreholes were drilled, two of which produced fluids from fractured Miocene andesite and altered Cretaceous to Eocene conglomerate at

133

Temporal Geochemical Variations In Volatile Emissions From Mount St Helens,  

Open Energy Info (EERE)

Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Temporal Geochemical Variations In Volatile Emissions From Mount St Helens, Usa, 1980-1994 Details Activities (2) Areas (1) Regions (0) Abstract: Fumarole discharges (95-560°C) collected from the dacite dome inside Mount St. Helens crater show temporal changes in their isotopic and chemical compositions. A ΔD vs. Δ18O plot shows that condensed waters from the gases are mixtures of meteoric and magmatic components, but that the apparent magmatic end-member in 1994 was depleted by about 7‰ in ΔD relative to the apparent end-member in 1980. Based on ΔD modeling, approximately 63% of shallow, post-1980 magma has yet to degas.

134

Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District,  

Open Energy Info (EERE)

Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Eastern California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Alteration And Geochemical Zoning In Bodie Bluff, Bodie Mining District, Eastern California Details Activities (0) Areas (0) Regions (0) Abstract: Banded, epithermal quartz-adularia veins have produced about 1.5 million ounces of gold and 7 million ounces of silver from the Bodie mining district, eastern California. The veins cut dacitic lava flows, pyroclastic rocks and intrusions. Sinter boulders occur in a graben structure at the top of Bodie Bluff and fragments of sinter and mineralized quartz veins occur in hydrothermal breccias nearby. Explosive venting evidently was part of the evolution of the ore-forming geothermal systems which, at one time,

135

Distribution and Geochemical Evolution of Fluoride in Groundwater of Taiyuan Basin, China  

Science Conference Proceedings (OSTI)

Hydrogeochemistry data were utilized to understand origin, distribution, and geochemical evolution of the high-fluoride groundwater in Taiyuan basin, China. In the study area, the spatial distribution of the high fluoride groundwater are strictly controlled ... Keywords: fluoride, geochemical mechanism

Xiangquan Li; Xinwei Hou; Zhichao Zhou; Lingxia Liu

2009-10-01T23:59:59.000Z

136

Crustal melting in the Himalayan orogen : field, geochemical and geochronological studies in the Everest region, Nepal  

E-Print Network (OSTI)

A combination of field studies and geochemical techniques were used to investigate the timing and processes involved in leucogranite generation in the Everest region of the Himalayan orogen. Geochemical investigations ...

Viskupic, Karen M. (Karen Marie), 1975-

2003-01-01T23:59:59.000Z

137

Theoretical and Experimental Evaluation of Chemical Reactivity  

E-Print Network (OSTI)

Reactive chemicals are presented widely in the chemical and petrochemical process industry. Their chemical reactivity hazards have posed a significant challenge to the industries of manufacturing, storage and transportation. The accidents due to reactive chemicals have caused tremendous loss of properties and lives, and damages to the environment. In this research, three classes of reactive chemicals (unsaturated hydrocarbons, self-reacting chemicals, energetic materials) were evaluated through theoretical and experimental methods. Methylcyclopentadiene (MCP) and Hydroxylamine (HA) are selected as representatives of unsaturated hydrocarbons and self-reacting chemicals, respectively. Chemical reactivity of MCP, including isomerization, dimerization, and oxidation, is investigated by computational chemistry methods and empirical thermodynamic–energy correlation. Density functional and ab initio methods are used to search the initial thermal decomposition steps of HA, including unimolecular and bimolecular pathways. In addition, solvent effects are also examined using water cluster methods and Polarizable Continuum Models (PCM) for aqueous solution of HA. The thermal stability of a basic energetic material, Nitroethane, is investigated through both theoretical and experimental methods. Density functional methods are employed to explore the initial decomposition pathways, followed by developing detailed reaction networks. Experiments with a batch reactor and in situ GC are designed to analyze the distribution of reaction products and verify reaction mechanisms. Overall kinetic model is also built from calorimetric experiments using an Automated Pressure Tracking Adiabatic Calorimeter (APTAC). Finally, a general evaluation approach is developed for a wide range of reactive chemicals. An index of thermal risk is proposed as a preliminary risk assessment to screen reactive chemicals. Correlations are also developed between reactivity parameters, such as onset temperature, activation energy, and adiabatic time to maximum rate based on a limited number, 37 sets, of Differential Scanning Calorimeter (DSC) data. The research shows broad applications in developing reaction mechanisms at the molecular level. The methodology of reaction modeling in combination with molecular modeling can also be used to study other reactive chemical systems.

Wang, Qingsheng

2010-08-01T23:59:59.000Z

138

Geochemical and physical properties of wetland soils at the Savannah River site  

Science Conference Proceedings (OSTI)

The Savannah River Site (SRS), located in Aiken, Allendale, and Barnwell Counties, South Carolina, is a nuclear production facility operated for the U.S. Department of Energy (DOE) by Westinghouse Savannah River Company (WSRC). To facilitate future human health and ecological risk assessments, treatability studies, remedial investigations, and feasibility studies for its wetland areas, SRS needs a database of background geochemical and physical properties of wetland soils. These data are needed for comparison to data collected from wetland soils that may have been affected by SRS operations. SRS contains 36,000 acres of wetlands and an additional 5,000 acres of bottom land soils subject to flooding. Recent studies of wetland soils near various waste units at SRS show that some wetlands have been impacted by releases of contaminants resulting from SRS operations (WSRC, 1992). Waste waters originating from the operations facilities typically have been discharged into seepage basins located in upland soils, direct discharge of waste water to wetland areas has been minimal. This suggests that impacted wetland areas have been affected indirectly as a result of transport mechanisms such as surface runoff, groundwater seeps, fluvial or sediment transport, and leaching. Looney et al. (1990) conducted a study to characterize the geochemical and physical properties of upland soils and shallow sediments on the SRS. A primary objective of the upland study was to collect the data needed to assess the qualitative and quantitative impacts of SRS operations on the environment. By comparing the upland soils data to data collected from waste units located in similar soils, SRS impacts could be assessed. The data were also intended to aid in selection of remediation alternatives. Because waste units at SRS have historically been located in upland areas, wetland soils were not sampled. (Abstract Truncated)

Dixon, K.L; Rogers, V.A.; Conner, S.P.; Cummings, C.L.; Gladden, J.B.; Weber, J.M.

1996-05-01T23:59:59.000Z

139

Merging High Resolution Geophysical and Geochemical Surveys to Reduce  

Open Energy Info (EERE)

Merging High Resolution Geophysical and Geochemical Surveys to Reduce Merging High Resolution Geophysical and Geochemical Surveys to Reduce Exploration Risk at Glass Buttes, Oregon Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Merging High Resolution Geophysical and Geochemical Surveys to Reduce Exploration Risk at Glass Buttes, Oregon Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Validation of Innovative Exploration Technologies Project Description This program will combine detailed gravity, high resolution aeromagnetic, and LIDAR data, all of which will be combined for structural modeling, with hyperspectral data, which will identify and map specific minerals and mineral assemblages that may point to upflow zones. The collection of these surveys and analyses of the merged data and model will be used to site deeper slim holes. Slim holes will be flow tested to determine whether or not Ormat can move forward with developing this resource. An innovative combination of geophysical and geochemical tools will significantly reduce risk in exploring this area, and the results will help to evaluate the value of these tools independently and in combination when exploring for blind resources where structure, permeability, and temperature are the most pressing questions. The slim holes will allow testing of models and validation of methods, and the surveys within the wellbores will be used to revise the models and site production wells if their drilling is warranted.

140

Synthesis of organic geochemical data from the Eastern Gas Shales  

Science Conference Proceedings (OSTI)

Over 2400 core and cuttings samples of Upper Devonian shales from wells in the Appalachian, Illinois, and Michigan Basins have been characterized by organic geochemical methods to provide a basis for accelerating the exploitation of this unconventional, gas-rich resource. This work was part of a program initiated to provide industry with criteria for locating the best areas for future drilling and for the development of stimulation methods that will make recovery of the resource economically attractive. The geochemical assessment shows that the shale, in much of the Appalachian, Illinois, and Michigan Basins is source rock that is capable of generating enormous quantities of gas. In some areas the shales are also capable of generating large quantities of oil as well. The limiting factors preventing these sources from realizing most of their potential are their very low permeabilities and the paucity of potential reservoir rocks. This geochemical data synthesis gives direction to future selection of sites for stimulation research projects in the Appalachian Basin by pinpointing those areas where the greatest volumes of gas are contained in the shale matrix. Another accomplishment of the geochemical data synthesis is a new estimate of the total resource of the Appalachian Basin. The new estimate of 2500 TCF is 25 percent greater than the highest previous estimates. This gives greater incentive to government and industry to continue the search for improved stimulation methods, as well as for improved methods for locating the sites where those improved stimulation methods can be most effectively applied.

Zielinski, R. E.; McIver, R. D.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Catalysis and Reactivity  

NLE Websites -- All DOE Office Websites (Extended Search)

understanding of basic principles of surface reactivity and its control by surface modification, on identification of active sites and full characterization of their electronic...

142

Validation of the WATEQ4 geochemical model for uranium  

SciTech Connect

As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite (UO/sub 2/(OH)/sub 2/ . H/sub 2/O), UO/sub 2/(OH)/sub 2/, and rutherfordine ((UO/sub 2/CO/sub 3/) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions.

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

1983-09-01T23:59:59.000Z

143

Geochemical characterization of geothermal systems in the Great Basin:  

Open Energy Info (EERE)

characterization of geothermal systems in the Great Basin: characterization of geothermal systems in the Great Basin: Implications for exploration, exploitation, and environmental issues Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Geochemical characterization of geothermal systems in the Great Basin: Implications for exploration, exploitation, and environmental issues Details Activities (0) Areas (0) Regions (0) Abstract: The objective of this ongoing project is the development of a representative geochemical database for a comprehensive range of elemental and isotopic parameters (i.e., beyond the typical data suite) for a range of geothermal systems in the Great Basin. Development of this database is one of the first steps in understanding the nature of geothermal systems in the Great Basin. Of particular importance in the Great Basin is utilizing

144

Lectures on geochemical interpretation of hydrothermal waters | Open Energy  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Lectures on geochemical interpretation of hydrothermal waters Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Lectures on geochemical interpretation of hydrothermal waters Abstract The alkali carbonates, Na, K, and Li, are relatively soluble at all temperatures and generally precipitate only where there is extreme evapora- tion. In contrast, the alkaline earth carbonates. Ca. Ht, Sr, and Ba, are moderately to sparingly soluble and commonly precipitate in bydrothecmal systems. Calcite is by far the most abundant and important carbonate found

145

Geochemical modeling of the Raft River geothermal field | Open Energy  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Geochemical modeling of the Raft River geothermal field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Geochemical modeling of the Raft River geothermal field Details Activities (1) Areas (1) Regions (0) Abstract: The results to date of chemical modeling of the Raft River KGRA are presented. Earlier work indicated a northwest-southeast anomaly in the contours. Modeling techniques applied to more complete data allowed further definition of the anomaly. Models described in this report show the source of various minerals in the geothermal water. There appears to be a regional heat source that gives rise to uniform conductive heat flow in the region, but convective flow is concentrated near the upwelling in the Crook well

146

Version 4.00 of the MINTEQ geochemical code  

DOE Green Energy (OSTI)

The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

Eary, L.E.; Jenne, E.A.

1992-09-01T23:59:59.000Z

147

Version 4. 00 of the MINTEQ geochemical code  

DOE Green Energy (OSTI)

The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

Eary, L.E.; Jenne, E.A.

1992-09-01T23:59:59.000Z

148

Reactivity of Nanoparticle Catalysts  

Science Conference Proceedings (OSTI)

... These, in turn, will provide a sustainable source of clean energy with applications in transportation and portable power generation. ...

2013-08-27T23:59:59.000Z

149

A geochemical model of the Kilauea east rift zone | Open Energy Information  

Open Energy Info (EERE)

A geochemical model of the Kilauea east rift zone A geochemical model of the Kilauea east rift zone Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A geochemical model of the Kilauea east rift zone Abstract N/A Author Donald Thomas Published Journal US Geological Survey Professional Paper 1350, 1987 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for A geochemical model of the Kilauea east rift zone Citation Donald Thomas. 1987. A geochemical model of the Kilauea east rift zone. US Geological Survey Professional Paper 1350. (!) . Retrieved from "http://en.openei.org/w/index.php?title=A_geochemical_model_of_the_Kilauea_east_rift_zone&oldid=682589" Categories: Missing Required Information References Uncited References Geothermal References

150

Sustainable Transport  

E-Print Network (OSTI)

THOUGHT PIECE Sustainable Transport by Melvin M. Webberwant to sustain any mode of transport only if we judge it todraconian in rejecting transport modes that have failed in

Webber, Melvin

2006-01-01T23:59:59.000Z

151

Reactive Power Compensator.  

DOE Patents (OSTI)

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

1992-07-28T23:59:59.000Z

152

Reactive power compensator  

DOE Patents (OSTI)

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

1992-01-01T23:59:59.000Z

153

Variational reactivity estimates: new analyses and new results  

SciTech Connect

A modified form of the variational estimate of the reactivity worth ofa perturbation was previously developed to extend the range of applicability of variational perturbation theory for perturbations leading to negative reactivity worths. Recent numerical results challenged the assumptions behind the modified form. In this paper, more results are obtained, leading to the conclusion that sometimes the modified form extends the range ofapplicability of variational perturbation theory for positive reactivity worths as well, and sometimes the standard variational form is more accurate for negative-reactivity perturbations. In addition, this paper proves that using the exact generalized adjoint function would lead to an inaccurate variational reactivity estimate when the error in the first-order estimate is large; the standard generalized adjoint function, an approximation to the exact one, leads to Lore accurate results. This conclusion is also demonstrated numerically. Transport calculations use the PARTISN multi group discrete ordinates code

Favorite, Jeffrey A [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

154

An Improved Equilibrium-Kinetics Speciation Algorithm For Redox...  

Open Energy Info (EERE)

Flow Systems Details Activities (0) Areas (0) Regions (0) Abstract: Reactive chemical transport occurs in a variety of geochemical environments, and over a broad range of...

155

Oxyferryl Heme Reactivity  

NLE Websites -- All DOE Office Websites (Extended Search)

Oxyferryl Heme Reactivity Using both Radiation and Photochemical Oxyferryl Heme Reactivity Using both Radiation and Photochemical Techniques A. M. English, T. Fox, G. Tsaprailis, C. W. Fenwick, J. F. Wishart, J. T. Hazzard, and G. Tollin Adv. Chem. Ser. 254, Ch. 6, pp. 81-98 Abstract: Flash photolysis and pulse radiolysis were used to generate reductants in situ to study the electron-transfer (ET) reactivity of the FeIV=O heme centers in myoglobin and cytochrome c peroxidase. Reduction of a5RuIII groups covalently bound to surface histidines allowed intramolecular RuII --> FeIV=O ET rates to be measured. Protonation of the oxene ligand was found to be largely rate determining in myoglobin, consistent with the lack of proton donors in its heme pocket. The large distance (21-23 Ă…) between surface histidines and the heme in wild-type

156

Reactivity of Acid Generators  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactivity of Acid Generators for Chemically Amplified Resists with Reactivity of Acid Generators for Chemically Amplified Resists with Low-Energy Electrons Atsuro Nakano, Takahiro Kozawa, Seiichi Tagawa, Tomasz Szreder, James F. Wishart, Toshiyuki Kai and Tsutomu Shimokawa Jpn. J. Appl. Phys., 45, L197-L200 (2006). [Find paper at the Japanese Journal of Applied Physics] Abstract: In chemically amplified resists for ionizing radiations such as electron beams and extreme ultraviolet (EUV), low-energy electrons play an important role in the pattern formation processes. The reactivity of acid generators with low-energy electrons was evaluated using solvated electrons in tetrahydrofuran, which were generated by a pulsed electron beam. The rate constants of acid generators with the solvated electrons ranged from 0.6 to 1.9 x 1011 M-1s-1

157

Geochemical data package for the Hanford immobilized low-activity tank waste performance assessment (ILAW PA)  

Science Conference Proceedings (OSTI)

Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are stored in single- and double-shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as low-activity waste is to vitrify the liquid/slurry and place the solid product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is the Hanford Immobilized Low-Activity Tank Waste (ILAW) Performance Assessment (PA) activity. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require prediction of contaminant migration from the facilities. This migration is expected to occur primarily via the movement of water through the facilities, and the consequent transport of dissolved contaminants in the porewater of the vadose zone. Pacific Northwest National Laboratory assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of the geochemical properties of the materials comprising the disposal facility, the disturbed region around the facility, and the physically undisturbed sediments below the facility (including the vadose zone sediments and the aquifer sediments in the upper unconfined aquifer). The geochemical properties are expressed as parameters that quantify the adsorption of contaminants and the solubility constraints that might apply for those contaminants that may exceed solubility constraints. The common parameters used to quantify adsorption and solubility are the distribution coefficient (K{sub d}) and the thermodynamic solubility product (K{sub sp}), respectively. In this data package, the authors approximate the solubility of contaminants using a more simplified construct, called the solution concentration limit, a constant value. In future geochemical data packages, they will determine whether a more rigorous measure of solubility is necessary or warranted based on the dose predictions emanating from the ILAW 2001 PA and reviewers' comments. The K{sub d}s and solution concentration limits for each contaminant are direct inputs to subsurface flow and transport codes used to predict the performance of the ILAW system. In addition to the best-estimate K{sub d}s, a reasonable conservative value and a range are provided. They assume that K{sub d} values are log normally distributed over the cited ranges. Currently, they do not give estimates for the range in solubility limits or their uncertainty. However, they supply different values for both the K{sub d}s and solution concentration limits for different spatial zones in the ILAW system and supply time-varying K{sub d}s for the concrete zone, should the final repository design include concrete vaults or cement amendments to buffer the system pH.

DI Kaplan; RJ Serne

2000-02-24T23:59:59.000Z

158

Testing geochemical modeling codes using New Zealand hydrothermal systems  

DOE Green Energy (OSTI)

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of selected portions of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will: (1) ensure that we are providing adequately for all significant processes occurring in natural systems; (2) determine the adequacy of the mathematical descriptions of the processes; (3) check the adequacy and completeness of thermodynamic data as a function of temperature for solids, aqueous species and gases; and (4) determine the sensitivity of model results to the manner in which the problem is conceptualized by the user and then translated into constraints in the code input. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions. The kinetics of silica precipitation in EQ6 will be tested using field data from silica-lined drain channels carrying hot water away from the Wairakei borefield.

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1993-12-01T23:59:59.000Z

159

Stream sediment detailed geochemical survey for Date Creek Basin, Arizona  

SciTech Connect

Results of the Date Creek Basin detailed geochemical survey are reported. Field and laboratory data are reported for 239 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Based on stream sediment geochemical data, significant concentrations of uranium are restricted to the Anderson Mine area. The 84th percentile concentrations of U-FL, U-NT, and U-FL/U-NT combined with low thorium/U-NT values reflect increased mobility and enrichment of uranium in the carbonate host rocks of that area. Elements characteristically associated with the uranium mineralization include lithium and arsenic. No well defined diffusion halos suggesting outliers of similar uranium mineralization were observed from the stream sediment data in other areas of the Date Creek Basin. Significant concentrations of U-FL or U-NT found outside the mine area are generally coincident with low U-FL/U-NT values and high concentrations of zirconium, titanium, and phosphorus. This suggests that the uranium is related to a resistate mineral assemblage derived from surrounding crystalline igneous and metamorphic rocks.

Butz, T.R.; Tieman, D.J.; Grimes, J.G.; Bard, C.S.; Helgerson, R.N.; Pritz, P.M.

1980-06-30T23:59:59.000Z

160

Reactive Power Compensating System.  

DOE Patents (OSTI)

The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

1985-01-04T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Reactive power compensating system  

DOE Patents (OSTI)

The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

1987-01-01T23:59:59.000Z

162

Grid Shunt Reactive Power Compensation  

Science Conference Proceedings (OSTI)

This report provides essential information on transmission grid shunt reactive power compensation, with particular focus on controllable reactive power sources such as the static var controller (SVC). Applying the information presented in this report can help electric utilities planning grid shunt reactive power compensation strategies or operating shunt reactive power compensation equipment to increase grid reliability, improve grid performance and prevent costly cascading outages. The report is intende...

2008-11-26T23:59:59.000Z

163

Reactive Air Aluminization  

DOE Green Energy (OSTI)

Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

2011-10-28T23:59:59.000Z

164

The hydrogeologic-geochemical model of Cerro Prieto revisited  

DOE Green Energy (OSTI)

As the exploitation of the Cerro Prieto, Mexico, geothermal field continues, there is increasing evidence that the hydrogeologic model developed by Halfman et al. (1984, 1986) presents the basic features controlling the movement of geothermal fluids in the system. At the present time the total installed capacity at Cerro Prieto is 620 MWe requiring the production of more than 10,500 tonnes/hr of a brine-steam mixture. This significant rate of fluid production has resulted in changes in reservoir thermodynamic conditions and in the chemistry of the produced fluids. After reviewing the hydrogeologic-geochemical model of Cerro Prieto, some of the changes observed in the field due to its exploitation are discussed and interpreted on the basis of the model. 21 refs., 11 figs., 1 tab.

Lippmann, M.J.; Halfman, S.E.; Truesdell, A.H.; Manon M., A.

1989-01-01T23:59:59.000Z

165

Multiphase fluid flow and subsequent geochemical transport in variably saturated fractured rocks: 1. Approaches  

E-Print Network (OSTI)

dissolution and precipitation. Here we present a comprehensive modeling approach and numerical methods

Xu, Tianfu; Pruess, Karsten

2000-01-01T23:59:59.000Z

166

Geochemical Determination of the Fate and Transport of Injected Fresh Wastewater to a Deep Saline Aquifer.  

E-Print Network (OSTI)

?? Deep well injection into non-potable saline aquifers of treated domestic wastewater has been used in Florida for decades as a safe and effective alternative… (more)

Walsh, Virginia M

2012-01-01T23:59:59.000Z

167

Geochemical exploration for uranium in the Red Desert, Wyoming  

SciTech Connect

Geochemical exploration techniques for uranium were performed at a known deposit, the ENQ uranium deposit, which is in arkosic sandstones of the Battle Spring Formation in the Red Desert of Wyoming. Regional gross-gamma aerial data did not indicate the most favorable terrain for follow-up surveys, but instead the radionuclide distribution mapped radioactive mudstones. The /sup 234/U//sup 238/U activity ratio and total uranium concentration in ground water were successful downflow indicators of the ENQ deposit. Helium concentration increased downflow in the ground water flowing from the deposit, while Cu, Pb, and Ba decreased. Radon emanometric techniques generally produced data that coincided with the equivalent uranium concentrations at shallow depth. Helium content in soil was interpreted to reflect local lithology and gaseous migration. Multielement geochemical analyses on soils were effective in delineating the general vicinity of the orebody. Factor analysis was used to recognize three lithologic subgroups. Leachable uranium in soils was the best indicator of subsurface mineralization for the entire subregional area. Equivalent uranium, as determined from the gamma-spectral borehole logs, revealed a consistent dispersion pattern within the host sand of the Battle Spring Formation, whereas gross gamma logs could not detect the subtle gradients in radioelement content. Halo models developed to explain the distribution of helium, radon, radioelements, and trace elements demonstrate uranium itself as the most mobile indicator. Radon and helium appear to reflect local generation from radium accumulations. Vertical leakage due to hydraulic flow against an impermeable barrier is interpreted to be the major secondary redistribution process responsible for the measureable surface signals.

Pacer, J.C.; Bramlett, L.; Moll, S.

1981-05-01T23:59:59.000Z

168

Documents: Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Search Documents: Search PDF Documents View a list of all documents Transportation PDF Icon Transportation Impact Assessment for Shipment of Uranium Hexafluoride (UF6) Cylinders...

169

Reactive Maintenance | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reactive Maintenance Reactive Maintenance Reactive Maintenance October 7, 2013 - 9:40am Addthis Reactive maintenance follows a run-it-until-it-breaks strategy where no actions or efforts are taken to maintain equipment as intended by the manufacturer. Studies indicate this is still the predominant mode of maintenance for Federal facilities. Advantages Reactive maintenance advantages are a double-edged sword. Federal agencies following a purely reactive maintenance strategy can expect little expenditures for manpower or system upkeep until something breaks. However, systems do break. With new equipment, Federal agencies can expect minimal incidents of failure. However, older equipment often experiences higher failure incidents and costlier repairs. Other advantages of reactive maintenance are:

170

Remediation of Uranium in the Hanford Vadose Zone Using Gas-Transported Reactants: Laboratory Scale Experiments in Support of the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau  

Science Conference Proceedings (OSTI)

This laboratory-scale investigation is focused on decreasing mobility of uranium in subsurface contaminated sediments in the vadose zone by in situ geochemical manipulation at low water content. This geochemical manipulation of the sediment surface phases included reduction, pH change (acidic and alkaline), and additions of chemicals (phosphate, ferric iron) to form specific precipitates. Reactants were advected into 1-D columns packed with Hanford 200 area U-contaminated sediment as a reactive gas (for CO2, NH3, H2S, SO2), with a 0.1% water content mist (for NaOH, Fe(III), HCl, PO4) and with a 1% water content foam (for PO4). Uranium is present in the sediment in multiple phases that include (in decreasing mobility): aqueous U(VI) complexes, adsorbed U, reduced U(IV) precipitates, rind-carbonates, total carbonates, oxides, silicates, phosphates, and in vanadate minerals. Geochemical changes were evaluated in the ability to change the mixture of surface U phases to less mobile forms, as defined by a series of liquid extractions that dissolve progressively less soluble phases. Although liquid extractions provide some useful information as to the generalized uranium surface phases (and are considered operational definitions of extracted phases), positive identification (by x-ray diffraction, electron microprobe, other techniques) was also used to positively identify U phases and effects of treatment. Some of the changes in U mobility directly involve U phases, whereas other changes result in precipitate coatings on U surface phases. The long-term implication of the U surface phase changes to alter U mass mobility in the vadose zone was then investigated using simulations of 1-D infiltration and downward migration of six U phases to the water table. In terms of the short-term decrease in U mobility (in decreasing order), NH3, NaOH mist, CO2, HCl mist, and Fe(III) mist showed 20% to 35% change in U surface phases. Phosphate addition (mist or foam advected) showed inconsistent change in aqueous and adsorbed U, but significant coating (likely phosphates) on U-carbonates. The two reductive gas treatments (H2S and SO2) showed little change. For long-term decrease in U reduction, mineral phases created that had low solubility (phosphates, silicates) were desired, so NH3, phosphates (mist and foam delivered), and NaOH mist showed the greatest formation of these minerals. In addition, simulations showed the greatest decrease in U mass transport time to reach groundwater (and concentration) for these silicate/phosphate minerals. Advection of reactive gasses was the easiest to implement at the laboratory scale (and presumably field scale). Both mist and foam advection show promise and need further development, but current implementation move reactants shorter distances relative to reactive gasses. Overall, the ammonia and carbon dioxide gas had the greatest overall geochemical performance and ability to implement at field scale. Corresponding mist-delivered technologies (NaOH mist for ammonia and HCl mist for carbon dioxide) performed as well or better geochemically, but are not as easily upscaled. Phosphate delivery by mist was rated slightly higher than by foam delivery simply due to the complexity of foam injection and unknown effect of U mobility by the presence of the surfactant.

Szecsody, James E.; Truex, Michael J.; Zhong, Lirong; Williams, Mark D.; Resch, Charles T.; McKinley, James P.

2010-01-04T23:59:59.000Z

171

Feed gas contaminant removal in ion transport membrane systems  

DOE Patents (OSTI)

An oxygen ion transport membrane process wherein a heated oxygen-containing gas having one or more contaminants is contacted with a reactive solid material to remove the one or more contaminants. The reactive solid material is provided as a deposit on a support. The one or more contaminant compounds in the heated oxygen-containing gas react with the reactive solid material. The contaminant-depleted oxygen-containing gas is contacted with a membrane, and oxygen is transported through the membrane to provide transported oxygen.

Underwood, Richard Paul (Allentown, PA); Makitka, III, Alexander (Hatfield, PA); Carolan, Michael Francis (Allentown, PA)

2012-04-03T23:59:59.000Z

172

Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley  

Open Energy Info (EERE)

Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley Region, Nevada (1996-1999) Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geochemical Data on Waters, Gases, Scales, and Rocks from the Dixie Valley Region, Nevada (1996-1999) Abstract This report tabulates an extensive geochemical database on waters, gases, scales,rocks, and hot-spring deposits from the Dixie Valley region, Nevada. The samples fromwhich the data were obtained were collected and analyzed during 1996 to 1999. Thesedata provide useful information for ongoing and future investigations on geothermalenergy, volcanism, ore deposits, environmental issues, and groundwater quality in thisregion. Authors Los Alamos National Laboratory and NM Published

173

Geochemical heterogeneity in the Hawaiian plume : constraints from Hawaiian volcanoes and Emperor seamounts  

E-Print Network (OSTI)

The 6000-km long, age-progressive linear Hawaii-Emperor Chain is one of the best defined hotspot tracks. This hotspot track plays an important role in the plume hypothesis. In this research, geochemical data on the ...

Huang, Shichun

2005-01-01T23:59:59.000Z

174

The dynamics of oceanic transform faults : constraints from geophysical, geochemical, and geodynamical modeling  

E-Print Network (OSTI)

Segmentation and crustal accretion at oceanic transform fault systems are investigated through a combination of geophysical data analysis and geodynamical and geochemical modeling. Chapter 1 examines the effect of fault ...

Gregg, Patricia Michelle Marie

2008-01-01T23:59:59.000Z

175

Migratory patterns of American shad (Alosa sapidissima) revealed by natural geochemical tags in otoliths  

E-Print Network (OSTI)

Geochemical signatures in the otoliths of diadromous fishes may allow for retrospective analyses of natal origins. In an assessment of river-specific signatures in American shad (Alosa sapidissima), an anadromous clupeid ...

Walther, Benjamin (Benjamin Dwaine)

2007-01-01T23:59:59.000Z

176

ENVIRONMENTAL REACTIVITY OF SOLID STATE HYDRIDE MATERIALS  

DOE Green Energy (OSTI)

In searching for high gravimetric and volumetric density hydrogen storage systems, it is inevitable that higher energy density materials will be used. In order to make safe and commercially acceptable condensed phase hydrogen storage systems, it is important to understand quantitatively the risks involved in using and handling these materials and to develop appropriate mitigation strategies to handle potential material exposure events. A crucial aspect of the development of risk identification and mitigation strategies is the development of rigorous environmental reactivity testing standards and procedures. This will allow for the identification of potential risks and implementation of risk mitigation strategies. Modified testing procedures for shipping air and/or water sensitive materials, as codified by the United Nations, have been used to evaluate two potential hydrogen storage materials, 2LiBH{sub 4} {center_dot} MgH{sub 2} and NH{sub 3}BH{sub 3}. The modified U.N. procedures include identification of self-reactive substances, pyrophoric substances, and gas-emitting substances with water contact. The results of these tests for air and water contact sensitivity will be compared to the pure material components where appropriate (e.g. LiBH{sub 4} and MgH{sub 2}). The water contact tests are divided into two scenarios dependent on the hydride to water mole ratio and heat transport characteristics. Air contact tests were run to determine whether a substance will spontaneously react with air in a packed or dispersed form. In the case of the 2LiBH{sub 4} {center_dot} MgH{sub 2} material, the results from the hydride mixture compared to the pure materials results showed the MgH{sub 2} to be the least reactive component and LiBH{sub 4} the more reactive. The combined 2LiBH{sub 4} {center_dot} MgH{sub 2} resulted in a material having environmental reactivity between these two materials. Relative to 2LiBH{sub 4} {center_dot} MgH{sub 2}, the chemical hydride NH{sub 3}BH{sub 3} was observed to be less environmentally reactive.

Gray, J; Donald Anton, D

2009-04-23T23:59:59.000Z

177

Geochemical Data Package for the 2005 Hanford Integrated Disposal Facility Performance Assessment  

Science Conference Proceedings (OSTI)

CH2M HILL Hanford Group, Inc. (CH2M HILL) is designing and assessing the performance of an integrated disposal facility (IDF) to receive low-level waste (LLW), mixed low-level waste (MLLW), immobilized low-activity waste (ILAW), and failed or decommissioned melters. The CH2M HILL project to assess the performance of this disposal facility is the Hanford IDF Performance Assessment (PA) activity. The goal of the Hanford IDF PA activity is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require prediction of contaminant migration from the facilities. This migration is expected to occur primarily via the movement of water through the facilities, and the consequent transport of dissolved contaminants in the vadose zone to groundwater where contaminants may be re-introduced to receptors via drinking water wells or mixing in the Columbia River. Pacific Northwest National Laboratory (PNNL) assists CH2M HILL in their performance assessment activities. One of the PNNL tasks is to provide estimates of the geochemical properties of the materials comprising the IDF, the disturbed region around the facility, and the physically undisturbed sediments below the facility (including the vadose zone sediments and the aquifer sediments in the upper unconfined aquifer). The geochemical properties are expressed as parameters that quantify the adsorption of contaminants and the solubility constraints that might apply for those contaminants that may exceed solubility constraints. The common parameters used to quantify adsorption and solubility are the distribution coefficient (Kd) and the thermodynamic solubility product (Ksp), respectively. In this data package, we approximate the solubility of contaminants using a more simplified construct, called the solution concentration limit, a constant value. The Kd values and solution concentration limits for each contaminant are direct inputs to subsurface flow and transport codes used to predict the performance of the IDF system. In addition to the best-estimate Kd values, a reasonable conservative value and a range are provided. The data package does not list estimates for the range in solubility limits or their uncertainty. However, the data package does provide different values for both the Kd values and solution concentration limits for different spatial zones in the IDF system and does supply time-varying Kd values for the cement solidified waste. The Kd values and solution concentration limits presented for each contaminant were previously presented in a report prepared by Kaplan and Serne (2000) for the 2001 ILAW PA, and have been updated to include applicable data from investigations completed since the issuance of that report and improvements in our understanding of the geochemistry specific to Hanford. A discussion is also included of the evolution of the Kd values recommended from the original 1999 ILAW PA through the 2001 ILAW and 2003 Supplement PAs to the current values to be used for the 2005 IDF PA for the key contaminants of concern: Cr(VI), nitrate, 129I, 79Se, 99Tc, and U(VI). This discussion provides the rationale for why certain Kd have changed with time.

Krupka, Kenneth M.; Serne, R JEFFREY.; Kaplan, D I.

2004-09-30T23:59:59.000Z

178

Geochemical and hydrodynamic controls on arsenic and trace metal cycling in a seasonally stratified US sub-tropical reservoir  

SciTech Connect

The phase distribution of trace metals and oxyanions was investigated within a South Texas watershed hosting a high density of surface uranium mine pits and tailings. The objectives of the study were to evaluate the potential impact of these old uranium mining sites on the watershed with particular emphasis on spatial and temporal changes in water quality of a reservoir that serves as the major source of freshwater to a population of {approx} 350,000 people in the region. A livestock pond, bordered by uranium mine tailings, was used as a model case-study site to evaluate the cycling of uranium mine-derived oxyanions under changing redox conditions. Although the pond showed seasonal thermal and chemical stratification, geochemical cycling of metals was limited to Co and Pb, which seemed to be mostly associated with redox cycling of Mn mineral phases, and U, which suggested reductive precipitation in the ponds hypolimnion. Uranium levels, however, were too low to support strong inputs from th e tailings into the water column of the pond. The strong relations observed between particulate Cr, Cs, V and Fe suggest that these metals are associated with a stable particulate phase (probably allochthonous aluminosilicates) enriched in unreactive iron. This observation is supported by a parallel relationship in sediments collected across a broad range of sediment depositional processed (and histories) in the basin. Arsenic, though selectively enriched in the ponds water column, remained stable and mostly in solution throughout the depth of the profile and showed no sign of geochemical cycling or interaction with Fe-rich particles. We found no evidence of anthropogenic impacts of U mines beyond the purely local scale. Arsenic does decrease in concentration downstream of uranium mining sites but its presence within the Nueces drainage basin is related to interactions between surface and ground waters with uranium-rich geological formations rather than long-scale transport of contaminants downstream of the U mine pits and tailings. As in Lyssy pond, arsenic (and other oxyanions) in Lake Corpus Christi's water column are not affected by the abundant presence of Fe-rich particles but instead behave conservatively throughout the entire period of study. A quantitative mass balance model, constructed using monthly hydrological data for the reservoir, provides quantitative evidence of seasonal evaporative concentration of as in surface waters demonstrating the predominance of hydrodynamic constraints, over geochemical ones, on the cycling of this metal in selected aquatic systems.

Brandenberger, Jill M.; Louchouarn, Patrick; Herbert, Bruce; Tissot, Philippe

2004-10-01T23:59:59.000Z

179

Second-order splitting schemes for a class of reactive systems  

Science Conference Proceedings (OSTI)

We consider the numerical time integration of a class of reaction-transport systems that are described by a set of ordinary differential equations for primary variables. In the governing equations, the terms involved may require the knowledge of secondary ... Keywords: 65L05, 80A32, Continuously stirred tank reactor, Operator splitting, Reaction-transport systems, Reduced description of reactive flows

Zhuyin Ren; Stephen B. Pope

2008-09-01T23:59:59.000Z

180

Reservoir simulation and geochemical study of Cerro Prieto I wells  

DOE Green Energy (OSTI)

Combined reservoir simulation and geochemical data analysis are used to investigate the effects of recharge and other reservoir processes occurring in the western part of the Cerro Prieto, Mexico, geothermal field (i.e., Cerro Prieto I area). Enthalpy-based temperatures and bottomhole temperatures are calculated based on simplified models of the system, considering different reservoir boundary conditions and zones of contrasting initial temperatures and reservoir properties. By matching the computed trends with geothermometer-based temperature and enthalpy histories of producing wells, the main processes active in the western area of Cerro Prieto are identified. This part of the geothermal system is strongly influenced by nearby groundwater aquifers; cooler waters readily recharge the reservoirs. In response to exploitation, the natural influx of cold water into the shallower alpha reservoir is mainly from the west and down Fault L, while the recharge to the deeper beta reservoir in this part of the field, seems to be only lateral, from the west and possibly south. 11 refs., 12 figs.

Lippmann, M.J. (Lawrence Berkeley Lab., CA (USA)); Truesdell, A.H. (Geological Survey, Menlo Park, CA (USA))

1990-03-01T23:59:59.000Z

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181

Reactive rules on the web  

Science Conference Proceedings (OSTI)

Reactive rules are used for programming rule-based, reactive systems, which have the ability to detect events and respond to them automatically in a timely manner. Such systems are needed on the Web for bridging the gap between the existing, passive ...

Bruno Berstel; Philippe Bonnard; François Bry; Michael Eckert; Paula-Lavinia P?trânjan

2007-09-01T23:59:59.000Z

182

GEOCENTRIFUGE STUDIES OF FLOW AND TRANSPORT IN POROUS MEDIA, FINAL REPORT FOR GRANT NUMBER DE-FG02-03ER63567 TO THE UNIVERSITY OF IDAHO (RW SMITH), ENVIRONMENTAL MANAGEMENT SCIENCE PROGRAM PROJECT NUMBER 86598, COUPLED FLOW AND REACTIVITY IN VARIABLY SATURATED POROUS MEDIA  

Science Conference Proceedings (OSTI)

Improved models of contaminant migration in heterogeneous, variably saturated porous media are required to better define the long-term stewardship requirements for U.S. Department of Energy (DOE) lands and to assist in the design of effective vadose-zone barriers to contaminant migrations. The development of these improved models requires field and laboratory results to evaluate their efficacy. However, controlled laboratory experiments simulating vadose conditions can require extensive period of time, and often are conducted at condition near saturation rather than the much drier conditions common in many contaminated arid vadose zone sites. Collaborative research undertaken by the Idaho National Laboratory (INL) and the University of Idaho as part of this Environmental Management Science Program project focused on the development and evaluation of geocentrifuge techniques and equipment that allows vadose zone experiments to be conducted for relevant conditions in time frames not possible in conventional bench top experiments. A key and novel aspect of the research was the use of the 2-meter radius geocentrifuge capabilities at the Idaho National Laboratory to conduct unsaturated transport experiments. Specifically, the following activities were conducted ** Reviewing of the theory of unsaturated flow in the geocentrifuge to establish the range of centrifuge accelerations/experimental conditions and the translation of centrifuge results to 1 gravity applications. ** Designing, constructing, and testing of in-flight experimental apparatus allowing the replication of traditional bench top unsaturated transport experiments on the geocentrifuge. ** Performing unsaturated 1-dimenstional column geocentrifuge experiments using conservative tracers to evaluate the effects of increased centrifugal acceleration on derived transport properties and assessing the scaling relationships for these properties. Because the application of geocentrifuge techniques to vadose transport is in its infancy experimental apparatus such as pumps, flow meters, columns, fraction collectors, etc. that would reliably function under the increased self weight experienced on the centrifuge had to be developed and tested as part of this project. Although, we initially planed to conduct experiments using reactive tracer and 2-dimensional heterogeneities, the cost and time associated with designing, building, and testing of experimental apparatus limited our experimental program to conservative tracer experiments using 1-dimensional columns. The results we obtained in this study indicate that the geocentrifuge technique is a viable experimental method for the study of subsurface processes where gravitational acceleration is important. The geocentrifuge allows experiments to be completed more quickly than tests conducted at 1-g, can be used to experimentally address important scaling issues, and permits experiments under a range of conditions that would be difficult or impossible using conventional approaches. The application of the geocentrifuge approaches and associated models developed in this project allows more meaningful investigation of DOE relevant vadose-zone issues under scalable conditions in time frames previously not obtainable.

Robert W. Smith; Carl D. Palmer; Earl D. Mattson

2007-06-15T23:59:59.000Z

183

Federal Energy Management Program: Reactive Maintenance  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactive Reactive Maintenance to someone by E-mail Share Federal Energy Management Program: Reactive Maintenance on Facebook Tweet about Federal Energy Management Program: Reactive Maintenance on Twitter Bookmark Federal Energy Management Program: Reactive Maintenance on Google Bookmark Federal Energy Management Program: Reactive Maintenance on Delicious Rank Federal Energy Management Program: Reactive Maintenance on Digg Find More places to share Federal Energy Management Program: Reactive Maintenance on AddThis.com... Sustainable Buildings & Campuses Operations & Maintenance Federal Requirements Program Management Commissioning Metering Computerized Maintenance Management Systems Maintenance Types Reactive Preventive Predictive Reliability-Centered Major Equipment Types

184

Geochemical Characterization of Chromate Contamination in the 100 Area Vadose Zone at the Hanford Site  

Science Conference Proceedings (OSTI)

The major objectives of the proposed study were to: 1.) determine the leaching characteristics of hexavalent chromium [Cr(VI)] from contaminated sediments collected from 100 Area spill sites; 2.) elucidate possible Cr(VI) mineral and/or chemical associations that may be responsible for Cr(VI) retention in the Hanford Site 100 Areas through the use of i.) macroscopic leaching studies and ii.) microscale characterization of contaminated sediments; and 3.) provide information to construct a conceptual model of Cr(VI) geochemistry in the Hanford 100 Area vadose zone. In addressing these objectives, additional benefits accrued were: (1) a fuller understanding of Cr(VI) entrained in the vadose zone that will that can be utilized in modeling potential Cr(VI) source terms, and (2) accelerating the Columbia River 100 Area corridor cleanup by providing valuable information to develop remedial action based on a fundamental understanding of Cr(VI) vadose zone geochemistry. A series of macroscopic column experiments were conducted with contaminated and uncontaminated sediments to study Cr(VI) desorption patterns in aged and freshly contaminated sediments, evaluate the transport characteristics of dichromate liquid retrieved from old pipelines of the 100 Area; and estimate the effect of strongly reducing liquid on the reduction and transport of Cr(VI). Column experiments used the with the column studies. Cr(VI) is found as ubiquitous coatings on sediment grain surfaces. Small, higher concentration, chromium sites are associated with secondary clay mineral inclusions, with occasional barium chromate minerals, and reduced to Cr(III) in association with iron oxides that are most likely magnetite primary minerals. Within the restricted access domains of sediment matrix, ferrous iron could also diffuse from in situ, high-surface-area minerals to cause the reductive immobilization of chromate. This process may be favored at microscale geochemical zones where ferrous iron could be supplied. Once nucleated, micrometer-scale precipitates are favored as growing locales for further accumulation, causing the formation of discrete zones of Cr(III).

Dresel, P. Evan; Qafoku, Nikolla; McKinley, James P.; Fruchter, Jonathan S.; Ainsworth, Calvin C.; Liu, Chongxuan; Ilton, Eugene S.; Phillips, J. L.

2008-07-16T23:59:59.000Z

185

Final Report: Molecular Basis for Microbial Adhesion and Geochemical Surface Reactions: A Study Across Scales  

SciTech Connect

Computational chemistry was used to help provide a molecular level description of the interactions of Gram-negative microbial membranes with subsurface materials. The goal is to develop a better understanding of the molecular processes involved in microbial metal binding, microbial attachment to mineral surfaces, and, eventually, oxidation/reduction reactions (electron transfer) that can occur at these surfaces and are mediated by the bacterial exterior surface. The project focused on the interaction of the outer microbial membrane, which is dominated by an exterior lipopolysaccharide (LPS) portion, of Pseudomonas aeruginosa with the mineral goethite and with solvated ions in the environment. This was originally a collaborative project with T.P. Straatsma and B. Lowery of the Pacific Northwest National Laboratory. The University of Alabama effort used electronic structure calculations to predict the molecular behavior of ions in solution and the behavior of the sugars which form a critical part of the LPS. The interactions of the sugars with metal ions are expected to dominate much of the microscopic structure and transport phenomena in the LPS. This work, in combination with the molecular dynamics simulations of Straatsma and the experimental electrochemistry and microscopy measurements of Lowry, both at PNNL, is providing new insights into the detailed molecular behavior of these membranes in geochemical environments. The effort at The University of Alabama has three components: solvation energies and structures of ions in solution, prediction of the acidity of the critical groups in the sugars in the LPS, and binding of metal ions to the sugar anions. An important aspect of the structure of the LPS membrane as well as ion transport in the LPS is the ability of the sugar side groups such as the carboxylic acids and the phosphates to bind positively charged ions. We are studying the acidity of the acidic side groups in order to better understand the ability of these groups to bind metal ions. We need to understand the solvation properties of the metal ions in solution and their ability to bind not only to the sugars but to proteins and to other anions. Our goal is then to be able to predict the ability of the side groups to bind metal ions. One result from the earlier molecular dynamics simulations is the exclusion of water from the inner hydrophobic part of the membrane. We thus need to investigate the binding of the cations in media with different dielectric constants.

Dixon, David Adams [The University of Alabama

2013-06-27T23:59:59.000Z

186

A Tariff for Reactive Power  

DOE Green Energy (OSTI)

Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would reduce system losses, increase circuit capacity, increase reliability, and improve efficiency. Reactive power is theoretically available from any inverter-based equipment such as photovoltaic (PV) systems, fuel cells, microturbines, and adjustable-speed drives. However, the installation is usually only economical if reactive power supply is considered during the design and construction phase. In this report, we find that if the inverters of PV systems or the generators of combined heat and power (CHP) systems were designed with capability to supply dynamic reactive power, they could do this quite economically. In fact, on an annualized basis, these inverters and generators may be able to supply dynamic reactive power for about $5 or $6 per kVAR. The savings from the local supply of dynamic reactive power would be in reduced losses, increased capacity, and decreased transmission congestion. The net savings are estimated to be about $7 per kVAR on an annualized basis for a hypothetical circuit. Thus the distribution company could economically purchase a dynamic reactive power service from customers for perhaps $6/kVAR. This practice would provide for better voltage regulation in the distribution system and would provide an alternate revenue source to help amortize the cost of PV and CHP installations. As distribution and transmission systems are operated under rising levels of stress, the value of local dynamic reactive supply is expected to grow. Also, large power inverters, in the range of 500 kW to 1 MW, are expected to decrease in cost as they become mass produced. This report provides one data point which shows that the local supply of dynamic reactive power is marginally profitable at present for a hypothetical circuit. We expect that the trends of growing power flow on the existing system and mass production of inverters for distributed energy devices will make the dynamic supply of reactive power from customers an integral component of economical and reliable system operation in the future.

Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Li, Fangxing [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator

2008-07-01T23:59:59.000Z

187

Ripple transport and the depletion of energetic particles in tokamaks  

Science Conference Proceedings (OSTI)

A local velocity-diffusion model is used to estimate the ripple transport-induced deviations from a Maxwellian distribution and the effects of such deviations on confinement time and reactivity.

Linsker, R.; Boozer, A.H.

1981-08-01T23:59:59.000Z

188

Geochemical interpretation of Kings Mountain, North Carolina, orientation area  

SciTech Connect

An orientation study has been made of uranium occurrences in the area of Kings Mountain, North Carolina. This is one of the orientation studies of known uranium occurrences that are being conducted in several geologic provinces and under various climatic (weathering) conditions to provide the technical basis for design and interpretation of NURE geochemical reconnaissance programs. The Kings Mountain area was chosen for study primarily because of the reported presence of high-uranium monazite. This 750-mi/sup 2/ area is in the deeply weathered southern Appalachian Piedmont and spans portions of the Inner Piedmont, Kings Mountain, and Charlotte geologic belts. Uranium concentration maps for ground and surface water samples clearly outline the outcrop area of the Cherryville Quartz Monzonite with highs up to 10 ppb uranium near the reported uraninite. Several surface water samples appear to be anomalous because of trace industrial contamination. Uranium concentration maps for -100 to +200 mesh stream sediments indicate the area of monazite abundance. Several samples with >100 ppM uranium content appear to be high in uranium-rich resistate minerals. When the uranium content of sediment samples is ratioed to the sum of Hf, Dy, and Th, the anomaly pattern shifts to coincide with uranium highs in ground and surface water samples. False anomalies from concentrations of monazite (Ce,ThPO/sub 4/), xenotime (Y,DyPO/sub 4/), and zircon (Zr,HfSiO/sub 4/) in stream sediment samples can thus be eliminated. Residual anomalies should be related to unusual uranium enrichment of these common minerals or to the presence of an uncommon uranium-rich mineral. Tantalum, beryllium, and tin in stream sediments correspond to high concentrations of uranium in stream and ground water but not to uranium in sediments. In an initial reconnaissance, several media should be sampled, and it is essential to correct uranium in sediments for the sample mineralogy.

Price, V.; Ferguson, R.B.

1977-01-01T23:59:59.000Z

189

Origin and geochemical evolution of the Michigan basin brine  

Science Conference Proceedings (OSTI)

Chemical and isotopic data were collected on 126 oil field brine samples and were used to investigate the origin and geochemical evolution of water in 8 geologic formations in the Michigan basin. Two groups of brine are found in the basin, the Na-Ca-Cl brine in the upper Devonian formations, and Ca-Na-Cl brine from the lower Devonian and Silurian aged formations. Water in the upper Devonian Berea, Traverse, and Dundee formations originated from seawater concentrated into halite facies. This brine evolved by halite precipitation, dolomitization, aluminosilicate reactions, and the removal of SO{sub 4} by bacterial action or by CaSO{sub 4} precipitation. The stable isotopic composition (D, O) is thought to represent dilution of evapo-concentrated seawater by meteoric water. Water in the lower Devonian Richfield, Detroit River Group, and Niagara-Salina formations is very saline Ca-Na-Cl brine. Cl/Br suggest it originated from seawater concentrated through the halite and into the MgSO{sub 4} salt facies, with an origin linked to the Silurian and Devonian salt deposits. Dolomitization and halite precipitation increased the Ca/Na, aluminosilicate reactions removed K, and bacterial action or CaSO{sub 4} precipitation removed SO{sub 4} from this brine. Water chemistry in the Ordovician Trenton-Black River formations indicates dilution of evapo-concentrated seawater by fresh or seawater. Possible saline end-members include Ordovician seawater, present-day upper Devonian brine, or Ca-Cl brine from the deeper areas in the basin.

Wilson, T.P.

1989-01-01T23:59:59.000Z

190

Colloid-Facilitated Transport of Radionuclides Through The Vadose Zone  

SciTech Connect

The main purpose of this project was to advance the basic scientific understanding of colloid and colloid-facilitated Cs transport of radionuclides in the vadose zone. We focused our research on the hydrological and geochemical conditions beneath the leadking waste tanks at the USDOE Hanford reservation. Specific objectives were (1) to determine the lability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste, (2) to characterize the interactions between colloidal particles and contaminants, i.e., Cs and Eu, (3) to determine the potential of Hanford sediments for in situe mobilization of colloids, (4) to evaluate colloid-facilitated radionuclide transport through sediments under unsaturated flow, (5) to implement colloid-facilitated contaminant transport mechanisms into a transport model, and (6) to improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facilitated transport for clean-up procedures and long-term risk assessment.

Markus Flury; James B. Harsh; John F. McCarthy' Peter C. Lichtner; John M. Zachara

2007-06-22T23:59:59.000Z

191

Reactive transport modeling of leaching tests and long-term ...  

Test-case B = macro-fractures Test-case C = micro-crack network + dual porosity @ANDRA. Cementitious materials workshop, Dec. 12-14 (2006), SRNL (USA) ...

192

Reactive transport modeling of geologic CO2 sequestration in...  

NLE Websites -- All DOE Office Websites (Extended Search)

Sleipner facility, where properties of the waste stream, target saline aquifer, and shale cap rock are relatively well constrained. The principle goal has been to discover and...

193

Reaction-based reactive transport modeling of Fe(III)  

Science Conference Proceedings (OSTI)

This research project (started Fall 2004) was funded by a grant to Argonne National Laboratory, The Pennsylvania State University, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Dr. Eric Roden, formerly at The University of Alabama, is now at the University of Wisconsin, Madison. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

Kemner, K.M.; Kelly, S.D.; Burgos, Bill; Roden, Eric

2006-06-01T23:59:59.000Z

194

Reactivity of heat treated chars  

DOE Green Energy (OSTI)

Reactivities of a number of chars produced from American coals varying in rank from lignite to anthracite have been measured in air, CO/sub 2/, steam and H/sub 2/. The variables chosen for the study were: rank of the parent coal, inorganic matter content, particle size, reaction temperature and pressure as well as heat treatment conditions used during char preparation. In all gasification atmospheres studied, reactivity plots for different chars are essentially of the same general shape and have three distinct regions. The reaction rate first increases slowly with time. The plot then goes through a maximum in slope, followed by a lengthy region of decreasing slope as burn-off approaches 100 percent. The shape of the burn-off curves can be explained on the basis of what is known about the development of porosity and surface area in microporous chars as they undergo gasification. Using an adjustable time parameter, equations have been developed which successfully correlate the reactivity data. Char reactivity decreases, in general, with increase in rank of the parent coal. Reactivities of chars in air, CO/sub 2/ and steam increase over 150-fold in going from a low volatile bituminous to a lignite parent coal; the spread in char reactivities in H/sub 2/ is only 30-fold. Removal of inorganic matter from coal precursors prior to their charring or from chars produced from the raw coals has a marked effect on char reactivity and surface area. Removal of inorganic matter (by acid washing) decreases, in general, reactivity of chars produced from lower rank coals, whereas reactivities of chars derived from higher rank coals increase.

Mahajan, O. P.; Walker, Jr., P. L.

1977-01-01T23:59:59.000Z

195

Investigating the potential for long-term permeable reactive barrier (PRB) monitoring from the electrical signatures associated with the reduction in reactive iron performance  

SciTech Connect

The objective of this work was to conduct laboratory and field experiments to determine the sensitivity of low frequency electrical measurements (resistivity and induced polarization) to the processes of corrosion and precipitation that are believed to limit permeable reactive barrier (PRB) performance. The research was divided into four sets of experiments that were each written up and submitted to a peer-reviewed journal: [1] A laboratory experiment to define the controls of aqueous chemistry (electrolyte activity; pH; valence) and total zero valent iron (Fe0) available surface area on the electrical properties of Fe0 columns. [2] A laboratory experiment to determine the impact of corrosion and precipitation on the electrical response of synthetic Fe0 columns as a result of geochemical reactions with NaSO4 and NaCO3 electrolytes. [3] Laboratory experiments on a sequence of cores retrieved from the Kansas City PRB to determine the magnitude of electrical and geochemical changes within a field active PRB after eight years of operation [4] Field-scale cross borehole resistivity and induced polarization monitoring of the Kansas City PRB to evaluate the potential of electrical imaging as a technology for non-invasive, long-term monitoring of indicators of reduced PRB performance This report first summarizes the findings of the four major experiments conducted under this research. The reader is referred to the four papers in Appendices 1-4 for a full description of each experiment, including motivation and significance, technical details, findings and implications. The deliverables of the project, including the publications, conference papers and new collaborative arrangements that have resulted are then described. Appendices 5-6 contain two technical reports written by co-PI Korte describing (1) supporting geochemical measurements, and (2) the coring procedure, conducted at the Kansas City PRB as part of this project.

Slater, Lee D.; Korte, N.; Baker, J.

2005-12-14T23:59:59.000Z

196

Transportation Demand  

Gasoline and Diesel Fuel Update (EIA)

page intentionally left blank page intentionally left blank 69 U.S. Energy Information Administration | Assumptions to the Annual Energy Outlook 2011 Transportation Demand Module The NEMS Transportation Demand Module estimates transportation energy consumption across the nine Census Divisions (see Figure 5) and over ten fuel types. Each fuel type is modeled according to fuel-specific technology attributes applicable by transportation mode. Total transportation energy consumption is the sum of energy use in eight transport modes: light-duty vehicles (cars and light trucks), commercial light trucks (8,501-10,000 lbs gross vehicle weight), freight trucks (>10,000 lbs gross vehicle weight), buses, freight and passenger aircraft, freight and passenger rail, freight shipping, and miscellaneous

197

Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area,  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Trace Element Geochemical Zoning in the Roosevelt Hot Springs Thermal Area, Utah Abstract Chemical interaction of thermal brines with reservoir rock in the Roosevelt Hot Springs thermal area has resulted in the development of distinctive trace element signatures. Geochemical analysis of soil sample, shallow temperature gradient drill hole cuttings and deep drill hole cutting provides a three dimensional perspective of trace element distributions within the system. Distributions of As, Hg and Li provide the clearest expression of hydrothermal activity. Comparison of these distribution

198

A Mineralogical Petrographic And Geochemical Study Of Samples From Wells In  

Open Energy Info (EERE)

Mineralogical Petrographic And Geochemical Study Of Samples From Wells In Mineralogical Petrographic And Geochemical Study Of Samples From Wells In The Geothermal Field Of Milos Island (Greece) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Mineralogical Petrographic And Geochemical Study Of Samples From Wells In The Geothermal Field Of Milos Island (Greece) Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents a study of hydrothermal alteration on Milos island, Greece. Examination of cores and cuttings from the two drill sites, obtained from a depth of about 1100 m in Milos geothermal field, showed that the hydrothermal minerals occurring in the rock include: K-feldspar, albite, chlorite, talc, diopside, epidote, muscovite, tremolite, kaolinite, montmorillonite, alunite, anhydrite, gypsum, calcite, and opaque minerals.

199

Road Transportation.  

E-Print Network (OSTI)

?? The recession of the early 1990’s marked the starting point for a transformation of the Swedish transportation industry. Cost oriented production techniques by the… (more)

Gudmundsson, Erik

2008-01-01T23:59:59.000Z

200

Transportation Revolution  

NLE Websites -- All DOE Office Websites (Extended Search)

To transform the vehicle sector, the U.S. auto manufacturing industry is actively developing new technologies and products. This transportation revolution will also affect...

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Transportation Security  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

For Review Only 1 Transportation Security Draft Annotated Bibliography Review July 2007 Preliminary Draft - For Review Only 2 Work Plan Task * TEC STG Work Plan, dated 8206,...

202

WIPP Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

Transuranic Waste Transportation Container Documents Documents related to transuranic waste containers and packages. CBFO Tribal Program Information about WIPP shipments across...

203

Trace metal speciation in saline waters affected by geothermal brines. [GEOCHEM  

DOE Green Energy (OSTI)

A description is given of the chemical equilibrium computer program GEOCHEM, which has been developed to calculate trace element speciation in soil, irrigation, drainage, or Salton Sea waters affected by geothermal brine. GEOCHEM is applied to irrigation water-brine mixtures and to Salton Sea water-brine mixtures in order to compute the chemical speciation of the elements Cd, Cu, Hg, Ni, Pb, and Zn, along with the oxyanions of As and B. The results suggest that the computer simulation can have an important effect on a program for managing brine spills. Appendices include published papers on related research.

Sposito, G.; Page, A.L.

1977-11-01T23:59:59.000Z

204

Geochemical Journal, Vol. 39, pp. 383 to 389, 2005 *Corresponding author (e-mail: ytakaha@hiroshima-u.ac.jp)  

E-Print Network (OSTI)

383 Geochemical Journal, Vol. 39, pp. 383 to 389, 2005 *Corresponding author (e-mail: ytakaha@hiroshima,3 1 Department of Earth & Planetary Systems Science, Hiroshima University, Higashi-Hiroshima 739 for Multiple Isotope Research for Astro-and Geochemical Evolution (MIRAGE), Hiroshima University, Higashi-Hiroshima

205

GeoSys.Chem: Estimate of reservoir fluid characteristics as first step in geochemical modeling of geothermal systems  

Science Conference Proceedings (OSTI)

A computer code GeoSys.Chem for the calculation of deep geothermal reservoir fluid characteristics from the measured physical-chemical parameters of separated water and condensed vapor samples obtained from drilled wells is presented. It was written ... Keywords: GeoChem, GeoSys.Chem, Geochemical modeling, Los Azufres, VB.NET

Mahendra P. Verma

2012-12-01T23:59:59.000Z

206

BNL | CFN: Transport of Hazardous Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation of Hazardous Materials and Nanomaterials Transportation of Hazardous Materials and Nanomaterials The following contains guidance for transporting materials to and from BNL and for on-site transfers. All staff and users must adhere to Laboratory guidelines when making plans to move materials either by commercial carrier or in rented or personal vehicles. BNL hazardous material transport guidelines apply for products that meet the definition of hazardous materials according to 49 CFR 171.8 and any nanomaterial that has known hazardous properties (toxic, flammable, reactive). BNL guidelines are also provided for all other nanomaterials even if they have not been identified as hazardous materials. Some materials may be transported in personal vehicles as per "Materials of Trade" (MOT) guidance. The regulations for transporting MOT are much

207

Transportation Center Seminar........ "Proactive Transmission Planning in  

E-Print Network (OSTI)

Transportation Center Seminar........ "Proactive Transmission Planning in Electricity Networks of the biggest problems of actual power-systems transmission planning is its reactive nature. We formulate-systems transmission planning, generation investment, and market operation decisions and propose a methodology to solve

Bustamante, Fabián E.

208

Transportation Market Distortions  

E-Print Network (OSTI)

of Highways, Volpe National Transportation Systems Center (Evaluating Criticism of Transportation Costing, VictoriaFrom Here: Evaluating Transportation Diversity, Victoria

Litman, Todd

2006-01-01T23:59:59.000Z

209

Defense Transportation - Center for Transportation Analysis  

NLE Websites -- All DOE Office Websites (Extended Search)

Defense Transportation The Center for Transportation Analysis provides analytical, planning, and operational support to defense transportation related projects. This includes the...

210

DETERMINATION OF SPECIFIC NEUTRONIC REACTIVITY  

DOE Patents (OSTI)

A method is given for production-line determination of the specific neutronic reactivity of such objects as individual nuclear fuel or neutron absorber elements and is notable for rapidity and apparatus simplicity. The object is incorporated in a slightly sub-critical chain fission reactive assembly having a discrete neutron source, thereby establishing a K/sub eff/ within the crucial range of 0.95 to 0.995. The range was found to afford, uniquely, flux- transient damped response in a niatter of seconds simultaneously with acceptable analytical sensitivity. The resulting neutron flux measured at a situs spaced from both object and source within the assembly serves as a calibrable indication of said reactivity.

Dessauer, G.

1960-05-10T23:59:59.000Z

211

Chemie der Erde 65 (2005) 4778 Geochemical and isotopic characteristics and evolution of the  

E-Print Network (OSTI)

Chemie der Erde 65 (2005) 47­78 Geochemical and isotopic characteristics and evolution) and Pichowiak (1994). ARTICLE IN PRESS W. Kramer et al. / Chemie der Erde 65 (2005) 47­7848 #12;These east (Oficina Viz Fm.) on a wide front to the west (Caleta Ligate Fm.). W. Kramer et al. / Chemie der

Siebel, Wolfgang

212

Geochemical constraints on the Palaeocene^ Miocene evolution of eastern Azerbaijan, with  

E-Print Network (OSTI)

Geochemical constraints on the Palaeocene^ Miocene evolution of eastern AzerbaijanEarth and Environmental Sciences, University of Texas at Arlington, Arlington,TX, USA zAzerbaijan NationalAcademy of Sciences Geology Institute ^ 29 A. H. Javid Pr., Baku, Azerbaijan ABSTRACT Fine-grained Palaeogene

Johnson, Cari

213

Geochemical modeling of the nuclear-waste repository system. A status report  

Science Conference Proceedings (OSTI)

The primary objective of the geochemical modeling task is to develop an understanding of the waste-repository geochemical system and provide a valuable tool for estimating future states of that system. There currently exists a variety of computer codes which can be used in geochemical modeling studies. Some available codes contain the framework for simulating a natural chemical system and estimating, within limits, the response of that system to environmental changes. By data-base enhancement and code development, this modeling technique can be even more usefully applied to a nuclear-waste repository. In particular, thermodynamic data on elements not presently in the data base but identified as being of particular hazard in the waste-repository system, need to be incorporated into the code to estimate the near-field as well as the far-field reactions during a hypothetical breach. A reaction-path-simulation code, which estimates the products of specific rock/water reactions, has been tested using basalt and ground water. Results show that the mass-transfer capabilities of the code will be useful in chemical-evolution studies and scenario analyses. The purpose of this report is to explain the status of geochemical modeling as it currently applies to the chemical system of a hypothetical nuclear-waste repository in basalt and to present the plan proposed for further developmet and application.

Deutsch, W.J.

1980-12-01T23:59:59.000Z

214

Geochemical anomalies in soil and sandstone overlying the Phoenix uranium deposit, Athabasca Basin Natural Resources  

E-Print Network (OSTI)

Collaboration Introduction The Wheeler River Property, host of Denison Mine's Phoenix uranium depositCo Mo Ni UU Geochemical anomalies in soil and sandstone overlying the Phoenix uranium deposit is the most efficient analytical method to detect these anomalies. Athabasca Basin Figure 1: Denison Mine

215

Soil geochemical survey over concealed kimberlites in the Attawapiskat area in northern Canada  

E-Print Network (OSTI)

lengths of 562 m over the Whiskey kimberlite and 740 m over the Yankee kimberlite pipe. B-horizon soil of the kimberlite pipes. Ammonium acetate leach at pH 5 (AA5) dissolves most of these carbonates, and shows geochemical characteristics of kimberlites in com- parison with peridotites, oceanic basalts (MORB

216

Z .Chemical Geology 145 1998 153159 z /Geochemical Earth Reference Model GERM  

E-Print Network (OSTI)

Z .Chemical Geology 145 1998 153­159 z /Geochemical Earth Reference Model GERM : description on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. The Z .GERM chemical Z . Z .reservoirs of the present-day Earth, from core to atmosphere; 2 present-day fluxes between

Mcdonough, William F.

217

Paper #194973 GEOCHEMICAL CHARACTERIZATION OF THE RESERVOIR HOSTING SHALE-GAS AND OIL in  

E-Print Network (OSTI)

Paper #194973 GEOCHEMICAL CHARACTERIZATION OF THE RESERVOIR HOSTING SHALE-GAS AND OIL a reservoir for shale-gas and oil. We examined organic-rich black shale, known as Macasty shale, of Upper SHALE-GAS AND OIL in THE SUBSURFACE OF ANTICOSTI ISLAND, CANADA Key Words: Provenance, Anticosti Island

218

Oak Ridge Geochemical Reconnaissance Program. [For National Uranium Resource Evaluation Program  

SciTech Connect

The Oak Ridge reconnaissance program is responsible for the geochemical survey in a 12-state area covering Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Iowa, Indiana, and Illinois as part of the National Uranium Resource Evaluation Program. The program concept is outlined and the planning and organization of the program is discussed. (JSR)

Arendt, J.W.

1977-03-01T23:59:59.000Z

219

OXYGEN TRANSPORT CERAMIC MEMBRANES  

SciTech Connect

This report covers the following tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints; Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability; Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres; Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures; Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability; and Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-04-01T23:59:59.000Z

220

Soil Iodine Determination in Deccan Syneclise, India: Implications for Near Surface Geochemical Hydrocarbon Prospecting  

Science Conference Proceedings (OSTI)

The association of iodine with organic matter in sedimentary basins is well documented. High iodine concentration in soils overlying oil and gas fields and areas with hydrocarbon microseepage has been observed and used as a geochemical exploratory tool for hydrocarbons in a few studies. In this study, we measure iodine concentration in soil samples collected from parts of Deccan Syneclise in the west central India to investigate its potential application as a geochemical indicator for hydrocarbons. The Deccan Syneclise consists of rifted depositional sites with Gondwana-Mesozoic sediments up to 3.5 km concealed under the Deccan Traps and is considered prospective for hydrocarbons. The concentration of iodine in soil samples is determined using ICP-MS and the values range between 1.1 and 19.3 ppm. High iodine values are characteristic of the northern part of the sampled region. The total organic carbon (TOC) content of the soil samples range between 0.1 and 1.3%. The TOC correlates poorly with the soil iodine (r{sup 2} propane-oxidizing bacterial populations in the soil. The integration of geochemical observations show the occurrence of elevated values in the northern part of the study area, which is also coincident with the presence of exposed dyke swarms that probably serve as conduits for hydrocarbon microseepage. The corroboration of iodine with existing geological, geophysical, and geochemical data suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons. Our study supports Deccan Syneclise to be promising in terms of its hydrocarbon prospects.

Mani, Devleena, E-mail: devleenatiwari@ngri.res.in [National Geophysical Research Institute (Council of Scientific and Industrial Research) (India); Kumar, T. Satish [Oil India Limited (India); Rasheed, M. A.; Patil, D. J.; Dayal, A. M.; Rao, T. Gnaneshwar; Balaram, V. [National Geophysical Research Institute (Council of Scientific and Industrial Research) (India)

2011-03-15T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Sustainable Transportation  

Energy.gov (U.S. Department of Energy (DOE))

The Office of Energy Efficiency and Renewable Energy (EERE) leads U.S. researchers and other partners in making transportation cleaner and more efficient through solutions that put electric drive...

222

electrifyingthefuture transportation  

E-Print Network (OSTI)

programme of electrification and the potential introduction of diesel hybrids. The Department for Transport vehicles Wind turbine systems Industrial equipment The lab has full ethernet capability which will enable

Birmingham, University of

223

Transportation Network Modeling in Passenger Transportation  

E-Print Network (OSTI)

. Summary & Future work 2 #12;NETPLAN Energy and Transportation Integration model A modeling frameworkTransportation Network Modeling in NETPLAN Passenger Transportation Venkat Krishnan Eirini;Outline 1. Introduction to NETPLAN 2. Transportation modeling- A review Freight Passenger 3. Developed

Daniels, Thomas E.

224

Treating water-reactive wastes  

DOE Green Energy (OSTI)

Some compounds and elements, such as lithium hydride, magnesium, sodium, and calcium react violently with water to generate much heat and produce hydrogen. The hydrogen can ignite or even form an explosive mixture with air. Other metals may react rapidly only if they are finely divided. Some of the waste produced at Los Alamos National Laboratory includes these metals that are contaminated with radioactivity. By far the greatest volume of water-reactive waste is lithium hydride contaminated with depleted uranium. Reactivity of the water-reactive wastes is neutralized with an atmosphere of humid nitrogen, which prevents the formation of an explosive mixture of hydrogen and air. When we adjust the temperature of the nitrogen and the humidifier, the nitrogen can be more or less humid, and the rate of reaction can be adjusted and controlled. Los Alamos has investigated the rates of reaction of lithium hydride as a function of the temperature and humidity, and, as anticipated, they in with in temperature and humidity. Los Alamos will investigate other variables. For example, the nitrogen flow will be optimized to conserve nitrogen and yet keep the reaction rates high. Reaction rates will be determined for various forms of lithium waste, from small chips to powder. Bench work will lead to the design of a skid-mounted process for treating wastes. Other water-reactive wastes will also be investigated.

Lussiez, G.W.

1993-01-01T23:59:59.000Z

225

Treating water-reactive wastes  

DOE Green Energy (OSTI)

Some compounds and elements, such as lithium hydride, magnesium, sodium, and calcium react violently with water to generate much heat and produce hydrogen. The hydrogen can ignite or even form an explosive mixture with air. Other metals may react rapidly only if they are finely divided. Some of the waste produced at Los Alamos National Laboratory includes these metals that are contaminated with radioactivity. By far the greatest volume of water-reactive waste is lithium hydride contaminated with depleted uranium. Reactivity of the water-reactive wastes is neutralized with an atmosphere of humid nitrogen, which prevents the formation of an explosive mixture of hydrogen and air. When we adjust the temperature of the nitrogen and the humidifier, the nitrogen can be more or less humid, and the rate of reaction can be adjusted and controlled. Los Alamos has investigated the rates of reaction of lithium hydride as a function of the temperature and humidity, and, as anticipated, they in with in temperature and humidity. Los Alamos will investigate other variables. For example, the nitrogen flow will be optimized to conserve nitrogen and yet keep the reaction rates high. Reaction rates will be determined for various forms of lithium waste, from small chips to powder. Bench work will lead to the design of a skid-mounted process for treating wastes. Other water-reactive wastes will also be investigated.

Lussiez, G.W.

1993-05-01T23:59:59.000Z

226

Modeling Studies on the Transport of Benzene and H2S in CO2-Water Systems  

Science Conference Proceedings (OSTI)

In this study, reactive transport simulations were used to assess the mobilization and transport of organics with supercritical CO{sub 2} (SCC), and the co-injection and transport of H{sub 2}S with SCC. These processes were evaluated at conditions of typical storage reservoirs, and for cases of hypothetical leakage from a reservoir to an overlying shallower fresh water aquifer. Modeling capabilities were developed to allow the simulation of multiphase flow and transport of H{sub 2}O, CO{sub 2}, H{sub 2}S, as well as specific organic compounds (benzene), coupled with multicomponent geochemical reaction and transport. This included the development of a new simulator, TMVOC-REACT, starting from existing modules of the TOUGH2 family of codes. This work also included an extensive literature review, calculation, and testing of phase-partitioning properties for mixtures of the phases considered. The reactive transport simulations presented in this report are primarily intended to illustrate the capabilities of the new simulator. They are also intended to help evaluate and understand various processes at play, in a more qualitative than quantitative manner, and only for hypothetical scenarios. Therefore, model results are not intended as realistic assessments of groundwater quality changes for specific locations, and they certainly do not provide an exhaustive evaluation of all possible site conditions, especially given the large variability and uncertainty in hydrogeologic and geochemical parameter input into simulations. The first step in evaluating the potential mobilization and transport of organics was the identification of compounds likely to be present in deep storage formations, and likely to negatively impact freshwater aquifers if mobilized by SCC. On the basis of a literature review related to the occurrence of these organic compounds, their solubility in water and SCC, and their toxicity (as reflected by their maximum contaminant levels MCL), benzene was selected as a key compound for inclusion into numerical simulations. Note that considering additional organic compounds and/or mixtures of such compounds in the simulations was beyond the scope of this study, because of the effort required to research, calculate, and validate the phase-partitioning data necessary for simulations. The injection of CO{sub 2} into a deep saline aquifer was simulated, followed by modeling the leaching of benzene by SCC and transport of benzene to an overlying aquifer along a hypothetical leakage pathway. One- and two-dimensional models were set up for this purpose. The target storage formation was assumed to initially contain about 10{sup -4} ppm benzene. Model results indicate that: (1) SCC efficiently extracts benzene from the storage formation. (2) Assuming equilibrium, the content of benzene in SCC is roportional to the concentration of benzene in the aqueous and solid phases. (3) Benzene may co-migrate with CO{sub 2} into overlying aquifers if a leakage pathway is present. Because the aqueous solubility of benzene in contact with CO{sub 2} is lower than the aqueous solubility of CO{sub 2}, benzene is actually enriched in the CO{sub 2} phase as the plume advances. (4) For the case studied here, the resulting aqueous benzene concentration in the overlying aquifer is on the same order of magnitude as the initial concentration in the storage formation. This generic modeling study illustrates, in a semi-quantitative manner, the possible mobilization of benzene by SCC. The extent to which the mobilization of this organic compound evolves temporally and spatially depends on a large number of controlling parameters and is largely site specific. Therefore, for more 'truly' predictive work, further sensitivity studies should be conducted, and further modeling should be integrated with site-specific laboratory and/or field experimental data. The co-injection of H{sub 2}S with CO{sub 2} into a deep saline aquifer was also simulated. In addition, the model considered leakage of the supercritical CO{sub 2}+H{sub 2}S mixture along a preferential p

Zheng, L.; Spycher, N.; Xu, T.; Apps, J.; Kharaka, Y.; Birkholzer, J.T.

2010-11-05T23:59:59.000Z

227

Coupled modeling of groundwater flow solute transport, chemical reactions and microbial processes in the 'SP' island  

Science Conference Proceedings (OSTI)

The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behavior and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by /Banwart et al, 1995/. Later, /Banwart et al, 1999/ presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by /Molinero, 2000/ who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulfate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of /Molinero, 2000/ and extends the preliminary microbial model of /Zhang, 2001/ by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfate concentration, thus adding additional evidence for the possibility of organic matter oxidation as the main source of bicarbonate. Model results indicate that pH and Eh are relatively stable. The dissolution-precipitation trends of hematite, pyrite and calcite also coincide with those indicated by the conceptual model. A thorough sensitivity analysis has been performed for the most relevant microbial parameters as well as for initial and boundary POC and DOC concentrations. The results of such analysis indicate that computed concentrations of bicarbonate, sulfate and DOC are sensitive to most of the microbial parameters, including specific growth rates, half-saturation constants, proportionality coefficients and yield coefficients. Model results, however, are less sensitive to the yield coefficient of DOC to iron-reducer bacteria. The sensitivity analysis indicates that changes in fermentation microbial parameters affect the growth of the iron-reducer, thus confirming the interconnection of both microbial processes. Computed concentrations of bicarbonate and sulfate are found to be sensitive to changes in the initial concentration of POC and the boundary concentration of DOC, but they lack sensitivity to the initial concentration of DOC and the boundary concentration of POC. The explanation for such result is related to the fact that POC has a low mobility due to its large molecular weight. DOC, however, can migrate downwards. Although a coupled hydro-bio-geochemical 1-D model can reproduce the observed ''unexpected'' increase of concentrations of bicarbonate and sulfate at a depth of 70 m, further modeling work is required in order to obtain a similar conclusion under the more realistic two dimensional conditions of the fracture zone.

Samper, Javier; Molinero, Jorg; Changbing, Yang; Zhang, Guoxiang

2003-12-01T23:59:59.000Z

228

GEOTECHNICAL/GEOCHEMICAL CHARACTERIZATION OF ADVANCED COAL PROCESS WASTE STREAMS  

Science Conference Proceedings (OSTI)

Thirteen solid wastes, six coals and one unreacted sorbent produced from seven advanced coal utilization processes were characterized for task three of this project. The advanced processes from which samples were obtained included a gas-reburning sorbent injection process, a pressurized fluidized-bed coal combustion process, a coal-reburning process, a SO{sub x}, NO{sub x}, RO{sub x}, BOX process, an advanced flue desulfurization process, and an advanced coal cleaning process. The waste samples ranged from coarse materials, such as bottom ashes and spent bed materials, to fine materials such as fly ashes and cyclone ashes. Based on the results of the waste characterizations, an analysis of appropriate waste management practices for the advanced process wastes was done. The analysis indicated that using conventional waste management technology should be possible for disposal of all the advanced process wastes studied for task three. However, some wastes did possess properties that could present special problems for conventional waste management systems. Several task three wastes were self-hardening materials and one was self-heating. Self-hardening is caused by cementitious and pozzolanic reactions that occur when water is added to the waste. All of the self-hardening wastes setup slowly (in a matter of hours or days rather than minutes). Thus these wastes can still be handled with conventional management systems if care is taken not to allow them to setup in storage bins or transport vehicles. Waste self-heating is caused by the exothermic hydration of lime when the waste is mixed with conditioning water. If enough lime is present, the temperature of the waste will rise until steam is produced. It is recommended that self-heating wastes be conditioned in a controlled manner so that the heat will be safely dissipated before the material is transported to an ultimate disposal site. Waste utilization is important because an advanced process waste will not require ultimate disposal when it is put to use. Each task three waste was evaluated for utilization potential based on its physical properties, bulk chemical composition, and mineral composition. Only one of the thirteen materials studied might be suitable for use as a pozzolanic concrete additive. However, many wastes appeared to be suitable for other high-volume uses such as blasting grit, fine aggregate for asphalt concrete, road deicer, structural fill material, soil stabilization additives, waste stabilization additives, landfill cover material, and pavement base course construction.

Edwin S. Olson; Charles J. Moretti

1999-11-01T23:59:59.000Z

229

Final Scientific/Technical Report – DE-FG02-06ER64172 – Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center – Subproject to Co-PI Eric E. Roden  

Science Conference Proceedings (OSTI)

This report summarizes research conducted in conjunction with a project entitled “Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center”, which was funded through the Integrative Studies Element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. William Burgos (The Pennsylvania State University) was the overall PI/PD for the project, which included Brian Dempsey (Penn State), Gour-Tsyh (George) Yeh (Central Florida University), and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The project focused on development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. The work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and was directly aligned with the Scheibe et al. ORNL FRC Field Project at Area 2. Area 2 is a shallow pathway for migration of contaminated groundwater to seeps in the upper reach of Bear Creek at ORNL, mainly through a ca. 1 m thick layer of gravel located 4-5 m below the ground surface. The gravel layer is sandwiched between an overlying layer of disturbed fill material, and 2-3 m of undisturbed shale saprolite derived from the underlying Nolichucky Shale bedrock. The fill was put in place when contaminated soils were excavated and replaced by native saprolite from an uncontaminated area within Bear Creek Valley; the gravel layer was presumably installed prior to addition of the fill in order to provide a stable surface for the operation of heavy machinery. The undisturbed saprolite is highly weathered bedrock that has unconsolidated character but retains much of the bedding and fracture structure of the parent rock (shale with interbedded limestone). Hydrological tracer studies conducted during the Scheibe et al. field project indicate that the gravel layer receives input of uranium from both upstream sources and from diffusive mass transfer out of highly contaminated fill and saprolite materials above and below the gravel layer. This research sought to examine biogeochemical processes likely to take place in the less conductive materials above and below the gravel during the in situ ethanol biostimulation experiment conducted at Area 2 during 2005-2006. The in situ experiment in turn examined the hypothesis that injection of electron donor into this layer would induce formation of a redox barrier in the less conductive materials, resulting in decreased mass transfer of uranium out these materials and attendant declines in groundwater U(VI) concentration. Our research was directed toward the following three major objectives relevant to formation of this redox barrier: (1) elucidate the kinetics and mechanisms of reduction of solid-phase Fe(III) and U(VI) in Area 2 sediments; (2) evaluate the potential for long-term sustained U(IV) reductive immobilization in Area 2 sediments; (3) numerically simulate the suite of hydrobiogeochemical processes occurring in experimental systems so as to facilitate modeling of in situ U(IV) immobilization at the field-scale.

Eric E. Roden

2009-03-17T23:59:59.000Z

230

Definition: Reactive Power | Open Energy Information  

Open Energy Info (EERE)

Reactive Power Reactive Power Jump to: navigation, search Dictionary.png Reactive Power The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and transformers. It also must supply the reactive losses on transmission facilities. Reactive power is provided by generators, synchronous condensers, or electrostatic equipment such as capacitors and directly influences electric system voltage. It is usually expressed in kilovars (kvar) or megavars (Mvar).[1] View on Wikipedia Wikipedia Definition In electric power transmission and distribution, volt-ampere reactive (var) is a unit used to measure reactive power in an AC electric

231

Particle Swarm Optimization Based Reactive Power Optimization  

E-Print Network (OSTI)

Reactive power plays an important role in supporting the real power transfer by maintaining voltage stability and system reliability. It is a critical element for a transmission operator to ensure the reliability of an electric system while minimizing the cost associated with it. The traditional objectives of reactive power dispatch are focused on the technical side of reactive support such as minimization of transmission losses. Reactive power cost compensation to a generator is based on the incurred cost of its reactive power contribution less the cost of its obligation to support the active power delivery. In this paper an efficient Particle Swarm Optimization (PSO) based reactive power optimization approach is presented. The optimal reactive power dispatch problem is a nonlinear optimization problem with several constraints. The objective of the proposed PSO is to minimize the total support cost from generators and reactive compensators. It is achieved by maintaining the whole system power loss as minimum...

Sujin, P R; Linda, M Mary

2010-01-01T23:59:59.000Z

232

Engine combustion control via fuel reactivity stratification  

Science Conference Proceedings (OSTI)

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

2013-12-31T23:59:59.000Z

233

Implementation of variably saturated flow into PHREEQC for the simulation of biogeochemical reactions in the vadose zone  

Science Conference Proceedings (OSTI)

A software tool for the simulation of one-dimensional unsaturated flow and solute transport together with biogeochemical reactions in the vadose zone was developed by integrating a numerical solution of Richards' equation into the geochemical modelling ... Keywords: Cation exchange, Geochemical modelling, Hydraulic properties, Reactive transport, Surface complexation, Unsaturated flow

L. Wissmeier; D. A. Barry

2010-04-01T23:59:59.000Z

234

Reactive and Catalytic Air Purification Materials - Energy ...  

Biomass and Biofuels; Building Energy Efficiency; Electricity Transmission; ... Target selectivity can be controlled through selection of reactive components.

235

Directional Reactive Power Ground Plane Transmission  

Directional Reactive Power Ground Plane Transmission Technology Summary ... The invention can transmit electrical power through the surface of the ...

236

Partnering Today: Technology Transfer Highlights Reactive ...  

THE LLNL TECHNOLOGY COMPANY PRODUCT Partnering Today: Technology Transfer Highlights Reactive NanoTechnologies Inc.: Temperature-controlled Precision Bonding

237

Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at Monticello, Utah Gamma Survey of a Permeable Reactive Barrier at...

238

Origin of geochemical heterogeneity in the mantle : constraints from volcanism associated with Hawaiian and Kerguelen mantle plumes  

E-Print Network (OSTI)

Lavas derived from long-lived mantle plumes provide important information of mantle compositions and the processes that created the geochemical heterogeneity within the mantle. Kerguelen and Hawaii are two long-lived mantle ...

Xu, Guangping

2007-01-01T23:59:59.000Z

239

Geochemical Aspects of the Carbonation of Magnesium Silicates in an Aqueous Medium  

NLE Websites -- All DOE Office Websites (Extended Search)

GEOCHEMICAL ASPECTS OF THE CARBONATION OF MAGNESIUM GEOCHEMICAL ASPECTS OF THE CARBONATION OF MAGNESIUM SILICATES IN AN AQUEOUS MEDIUM George D. Guthrie, Jr. (gguthrie@lanl.gov 505-665-6340) J. William Carey (bcarey@lanl.gov 505-667-5540) Deborah Bergfeld (debberrg@lanl.gov 505-667-1812) Darrin Byler (dbyler@lanl.gov 505-665-9562) Steve Chipera (chipera@lanl.gov 505-667-1110) Hans-Joachim Ziock (ziock@lanl.gov 505-667-7265) Hydrology, Geochemistry, & Geology Los Alamos National Laboratory Los Alamos, NM 87545 Klaus Lackner (ksl@lanl.gov 505-667-5694) Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM and Columbia University, New York, NY KEYWORDS: CO 2 sequestration, magnesium silicate, mineral carbonation INTRODUCTION The volume of carbon dioxide associated with the use of fossil fuels to produce

240

Field-based tests of geochemical modeling codes using New Zealand hydrothermal systems  

DOE Green Energy (OSTI)

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions.

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1994-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Evaluation of selected geochemical anomalies in Colorado and the Southeastern US. Final report  

SciTech Connect

This study demonstrates the utility of HSSR geochemical data from stream sediment in exploration for uranium. In the southeastern US, four uraniferous occurrences and associated radiometric anomalies were identified in areas where uranium mineralization has not been previously reported. At two localities, assays of about .01% have been obtained from saprolite. There is some evidence which suggests that uranium may have been leached at these localities and that higher grades of U are likely at depth.

Carpenter, R H

1980-08-01T23:59:59.000Z

242

Proceedings of the second workshop on hydrologic and geochemical monitoring in the Long Valley Caldera  

DOE Green Energy (OSTI)

A workshop was held to review the results of hydrologic and geochemical monitoring and scientific drilling in the Long Valley caldera. Such monitoring is being done to detect changes in the hydrothermal system induced by ongoing magmatic and techonic processes. Data from a 2400-ft deep core hole completed in June 1986 were presented at the 1986 workshop and participants discussed the need and rationale for siting locations for future scientific drilling in the caldera.

Sorey, M.L.; Farrar, C.D.; Wollenberg, H.A. (eds.)

1986-12-01T23:59:59.000Z

243

Permeable Reactive Barriers | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barriers Permeable Reactive Barrier Field Projects Durango, Colorado DOE installed a PRB in October 1995 to treat ground water from a uranium mill tailings disposal site at Durango, Colorado Read more Cañon City, Colorado ESL personnel conduct tests and help evaluate performance at other PRB sites, such as Cotter Corporation's Cañon City site in Colorado. Read more Monticello, Utah Installation of a PRB hydraulically downgradient of the Monticello, Utah, millsite was completed June 30, 1999, as an Interim Remedial Action. Read more A permeable reactive barrier (PRB) is a zone of reactive material placed underground to intercept and react with a contaminant plume in ground water. Typically, PRBs are emplaced by replacing soils with reactive

244

Transportation and its Infrastructure  

E-Print Network (OSTI)

Transport and its infrastructure Coordinating Lead Authors:5 Transport and its infrastructure Chandler, K. , E. Eberts,5 Transport and its infrastructure Sausen, R. , I. Isaksen,

2007-01-01T23:59:59.000Z

245

Intelligent Transport Systems  

E-Print Network (OSTI)

in Sustainable Urban Transport: City Interview Synthesis (of Leeds, Institute for Transport Studies, forthcoming.I NTELLIGENT TRANSPORT SYSTEMS LINKING TECHNOLOGY AND

Deakin, Elizabeth; Frick, Karen Trapenberg; Skabardonis, Alexander

2009-01-01T23:59:59.000Z

246

Preface: Nonclassical Transport  

E-Print Network (OSTI)

models of solute transport in highly heterogeneous geologicSemenov. 2008b. Nonclassical transport processes in geologicand L. Matveev. 2008. Transport regimes and concentration

Bolshov, L.

2010-01-01T23:59:59.000Z

247

Sustainability and Transport  

E-Print Network (OSTI)

Gilbert is a Toronto-based transport and energy consultantof the forthcoming book Transport Revolutions: Making theand substantial transition to transport systems based on

Gilbert, Richard

2006-01-01T23:59:59.000Z

248

Transportation Energy Futures  

E-Print Network (OSTI)

A Comparative Analysis of Future Transportation Fuels. ucB-prominentlyin our transportation future, powering electricTransportation Energy Futures Daniel Sperling Mark A.

DeLuchi, Mark A.

1989-01-01T23:59:59.000Z

249

Achieving Sustainable Transportation  

E-Print Network (OSTI)

a serious concern for future transportation planning, but itplanning for the future. Transportation should be at the topsustainable transportation look like? Again, the future will

Mason, Jonathan

2006-01-01T23:59:59.000Z

250

Transportation Issues  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Issues Issues and Resolutions - Compilation of Laboratory Transportation Work Package Reports Prepared for U.S. Department of Energy Used Fuel Disposition Campaign Compiled by Paul McConnell Sandia National Laboratories September 30, 2012 FCRD-UFD-2012-000342 Transportation Issues and Resolutions ii September 2012 Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. DISCLAIMER This information was prepared as an account of work sponsored by an agency of the U.S. Government. Neither the U.S. Government nor any

251

Transportation Security  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

For Review Only 1 Transportation Security Draft Annotated Bibliography Review July 2007 Preliminary Draft - For Review Only 2 Work Plan Task * TEC STG Work Plan, dated 8/2/06, Product #16, stated: "Develop an annotated bibliography of publicly-available documents related to security of radioactive material transportation." * Earlier this year, a preliminary draft annotated bibliography on this topic was developed by T-REX , UNM, to initially address this STG Work Plan Task. Preliminary Draft - For Review Only 3 Considerations in Determining Release of Information * Some "Publicly-available" documents could potentially contain inappropriate information according to standards set by DOE information security policy and DOE Guides. - Such documents would not be freely

252

LNG transportation  

Science Conference Proceedings (OSTI)

In the beginning of 1965, the participants to the starting up of first French LNG transportation system between ARZEW and LE HAVRE were indeed pioneers when they started the cool-down of the three tanks of LE HAVRE, with a LNG freight delivered by old liberty-ship ''BEAUVAIS''. Could they forecast the development of LNG industry in FRANCE and in the world and imagine that modest 'JULES VERNE' and his two english brothers would have, 25 years later, 80 successors - more than five times as big, for the main part of them, that 12 liquefaction plants would be running in the world, supplying about twenty LNG terminals. For the first time, a country - FRANCE - can draw the lessons from the exploitation of the 3 LNG transportation systems during a long period. That is the subject of the present paper.

Picard, J.

1988-01-01T23:59:59.000Z

253

Transportation Planning & Decision Science Group Transportation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Poster Presentations: Stacy Davis - "Transportation Data Programs: Transportation Energy Data Book, Vehicle Technologies Market Report, and the Vehicle Technologies Fact of...

254

Transportation Research Internship Program  

E-Print Network (OSTI)

Transportation Research Internship Program Civil & Coastal Engineering Overview The Transportation Research Internship Program (TRIP) is conducted by the Transportation Research Center (TRC) and the Center is to provide undergraduates an exciting opportunity to learn about transportation engineering

Slatton, Clint

255

On Perturbation Components Correspondence between Diffusion and Transport  

SciTech Connect

We have established a correspondence between perturbation components in diffusion and transport theory. In particular we have established the correspondence between the leakage perturbation component of the diffusion theory to that of the group self scattering in transport theory. This has been confirmed by practical applications on sodium void reactivity calculations of fast reactors. Why this is important for current investigations? Recently, there has been a renewed interest in designing fast reactors where the sodium void reactivity coefficient is minimized. In particular the ASTRID8,9 reactor concept has been optimized with this goal in mind. The correspondence on the leakage term that has been established here has a twofold implication for the design of this kind of reactors. First, this type of reactor has a radial reflector; therefore, as shown before, the sodium void reactivity coefficient calculation requires the use of transport theory. The minimization of the sodium reactivity coefficient is normally done by increasing the leakage component that has a negative sign. The correspondence established in this paper allows to directly look at this component in transport theory. The second implication is related to the uncertainty evaluation on sodium void reactivity. As it has shown before, the total sodium void reactivity effect is the result of a large compensation (opposite sign) between the scattering (called often spectral) component and the leakage one. Consequently, one has to evaluate separately the uncertainty on each separate component and then combine them statistically. If one wants to compute the cross section sensitivity coefficients of the two different components, the formulation established in this paper allows to achieve this goal by playing on the contribution to the sodium void reactivity coming from the group self scattering of the sodium cross section.

G. Palmiotti

2012-11-01T23:59:59.000Z

256

Benchmarks for Quantifying Fuel Reactivity Depletion Uncertainty  

Science Conference Proceedings (OSTI)

Analytical methods, described in this report, are used to systematically determine experimental fuel sub-batch reactivities as a function of burnup. Fuel sub-batch reactivities are inferred using more than 600 in-core pressurized water reactor (PWR) flux maps taken during 44 cycles of operation at the Catawba and McGuire nuclear power plants. The analytical methods systematically search for fuel sub-batch reactivities that minimize differences between measured and computed reaction rates, using Studsvik ...

2011-08-08T23:59:59.000Z

257

TRANSPORTATION SYSTEMS Transportation systems are the building  

E-Print Network (OSTI)

TRANSPORTATION SYSTEMS Transportation systems are the building blocks of modern society. Efficient mobility improves the quality of life. However, transportation systems by their very nature also affect quality. The transportation systems graduate pro- gram provides in-depth knowledge on the design

Wang, Yuhang

258

Rejuvenating Permeable Reactive Barriers by Chemical Flushing  

Energy.gov (U.S. Department of Energy (DOE))

Final Report:Rejuvenating Permeable Reactive Barriers by Chemical Flushing,U.S. Environmental Protection Agency, Region 8 Support.August 2004

259

ENGINE COMBUSTION CONTROL VIA FUEL REACTIVITY ...  

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a ...

260

Electrochemistry of Enargite: Reactivity in Alkaline Solutions  

Science Conference Proceedings (OSTI)

The reactivity of enargite samples from Montana, US and Quiruvilca, Peru were studied under alkaline conditions, pH range of 8-13, using a cyclic voltammetry ...

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Reactive Air Aluminizing - Energy Innovation Portal  

Reactive Air Aluminizing is a process for applying a protective coating on steel components in solid oxide fuel ... Building Energy Efficiency; ...

262

Reactive Air Aluminizing - Energy Innovation Portal  

Reactive Air Aluminizing is a process for applying a protective coating on steel components in solid oxide fuel cells and other high temperature electrochemical devices.

263

Intelligent Transportation Systems - Center for Transportation Analysis  

NLE Websites -- All DOE Office Websites (Extended Search)

Intelligent Transportation Systems Intelligent Transportation Systems The Center for Transportation Analysis does specialty research and development in intelligent transportation systems. Intelligent Transportation Systems (ITS) are part of the national strategy for improving the operational safety, efficiency, and security of our nation's highways. Since the early 1990s, ITS has been the umbrella under which significant efforts have been conducted in research, development, testing, deployment and integration of advanced technologies to improve the measures of effectiveness of our national highway network. These measures include level of congestion, the number of accidents and fatalities, delay, throughput, access to transportation, and fuel efficiency. A transportation future that includes ITS will involve a significant improvement in these

264

Data for the geochemical investigation of UMTRAP designated site at Ambrosia Lake, New Mexico  

SciTech Connect

This report contains the geochemical data and the methods of data collection from the former tailings site at Ambrosia Lake, New Mexico. Data are from a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. Selected solid samples are water extracted to remove easily soluble salts and acid extracted to remove carbonates and hydroxides. The waters, extracts, and solid samples were analyzed for selected major and trace elements. 3 refs., 2 figs., 1 tab.

Markos, G.; Bush, K.J.

1983-09-01T23:59:59.000Z

265

Proceedings: Fossil Plant Layup and Reactivation Conference  

Science Conference Proceedings (OSTI)

In recent years, the layup and reactivation of fossil-fired power plants has become more important as increasing numbers of utilities develop a need for retaining capacity not currently needed. A 1992 EPRI conference highlighted key technical issues, focusing on proven layup procedures, descriptions of layup equipment and preservation methods, layup and reactivation case studies, and summaries of regulatory issues.

1992-10-01T23:59:59.000Z

266

Geochemical Implications of CO2 Leakage Associated with Geologic Storage: A Review  

SciTech Connect

Leakage from deep storage reservoirs is a major risk factor associated with geologic sequestration of carbon dioxide (CO2). Different scientific theories exist concerning the potential implications of such leakage for near-surface environments. The authors of this report reviewed the current literature on how CO2 leakage (from storage reservoirs) would likely impact the geochemistry of near surface environments such as potable water aquifers and the vadose zone. Experimental and modeling studies highlighted the potential for both beneficial (e.g., CO2 re sequestration or contaminant immobilization) and deleterious (e.g., contaminant mobilization) consequences of CO2 intrusion in these systems. Current knowledge gaps, including the role of CO2-induced changes in redox conditions, the influence of CO2 influx rate, gas composition, organic matter content and microorganisms are discussed in terms of their potential influence on pertinent geochemical processes and the potential for beneficial or deleterious outcomes. Geochemical modeling was used to systematically highlight why closing these knowledge gaps are pivotal. A framework for studying and assessing consequences associated with each factor is also presented in Section 5.6.

Harvey, Omar R.; Qafoku, Nikolla; Cantrell, Kirk J.; Brown, Christopher F.

2012-07-09T23:59:59.000Z

267

Trace metal speciation in saline waters affected by geothermal brines. Final technical report. [GEOCHEM  

DOE Green Energy (OSTI)

The computer program GEOCHEM was developed and applied to calculate the speciation of trace elements, such as Li, B, Mn, Co, Ni, Cu, Zn, Pb, and As, in mixtures of geothermal brines with soil waters. A typical speciation calculation involved the simultaneous consideration of about 350 inorganic and organic complexes and about 80 possible solid phases that could form among the macro- and microconstituents in the mixtures. The four geothermal brines chosen for study were from the East Mesa, Heber, and Salton Sea KGRA's. Two examples of East Mesa brine were employed in order to illustrate the effect of brine variability within a given KGRA. The soil waters chosen for study were the Holtville, Rosita, and Vint soil solutions and the Vail 4 drain water. These waters were mixed with the four brines to produce 1%, 5%, and 10% brine combinations. The combinations then were analyzed with the help of GEOCHEM and were interpreted in the context of two proposed general contamination scenarios. The results of the speciation calculations pointed to the great importance, in brine, of sulfide as a precipitating agent for trace metals and of borate as a trace metal-complexing ligand. In general, precipitation and/or exchange adsorption in soil were found to reduce the levels of trace metals well below harmful concentrations. The principal exceptions were Li and B, which did not precipitate and which were at or very hear harmful levels in the soil water-brine mixtures.

Sposito, G.

1979-07-01T23:59:59.000Z

268

Reactivity worth measurements at the IPEN/MB-01 nuclear reactor  

Science Conference Proceedings (OSTI)

Researches that aim to improve the performance of neutron transport codes and quality of nuclear cross section databases are very important to increase the accuracy of simulations and the quality of the analysis and prediction of phenomena in the nuclear field. In this context, relevant experimental data such as reactivity worth measurements are needed. The objective of this work was to perform a series of experiments of reactivity worth measurements, using a digital reactivity meter developed at IPEN. The experiments employed small metallic and ceramic samples inserted in the central region of the core of the experimental IPEN/MB-01 reactor. The theoretical analysis was performed by the MCNP-5 reactor physics code, developed and maintained by Los Alamos National Laboratory, and the ENDF/B-VII.0 nuclear data library.

Pinto, Leticia Negrao; Santos, Adimir dos [Nuclear Engineering Center, Nuclear and Energy Research Institute- IPEN/CNEN-SP (Brazil)

2013-05-06T23:59:59.000Z

269

Simulations of highly reactive fluids  

SciTech Connect

We report density functional molecular dynamics simulations to determine the early chemical events of hot (T = 3000 K) and dense (1.97 g/cm{sup 3}, V/V{sub 0} = 0.68) nitromethane (CH{sub 3}NO{sub 2}). The first step in the decomposition process is an intermolecular proton abstraction mechanism that leads to the formation of CH{sub 3}NO{sub 2}H and the aci ion H{sub 2}CNO{sub 2}{sup -}, in support of evidence from static high-pressure and shock experiments. An intramolecular hydrogen transfer that transforms nitromethane into the aci acid form, CH{sub 2}NO{sub 2}H, accompanies this event. This is the first confirmation of chemical reactivity with bond selectivity for an energetic material near the condition of fully reacted specimen. We also report the decomposition mechanism followed up to the formation of H{sub 2}O as the first stable product.

Fried, L E; Manaa, M R; Reed, E J

2005-07-21T23:59:59.000Z

270

Transportation Security | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Security SHARE Global Threat Reduction Initiative Transportation Security Cooperation Secure Transport Operations (STOP) Box Security of radioactive material while...

271

Transportation Applications  

DOE Green Energy (OSTI)

The purpose of this project is to systematically identify and examine possible near and long-term ecological and environmental effects from the production of hydrogen from various energy sources based on the DOE hydrogen production strategy and the use of that hydrogen in transportation applications. This project uses state-of-the-art numerical modeling tools of the environment and energy system emissions in combination with relevant new and prior measurements and other analyses to assess the understanding of the potential ecological and environmental impacts from hydrogen market penetration. H2 technology options and market penetration scenarios will be evaluated using energy-technology-economics models as well as atmospheric trace gas projections based on the IPCC SRES scenarios including the decline in halocarbons due to the Montreal Protocol. Specifically we investigate the impact of hydrogen releases on the oxidative capacity of the atmosphere, the long-term stability of the ozone layer due to changes in hydrogen emissions, the impact of hydrogen emissions and resulting concentrations on climate, the impact on microbial ecosystems involved in hydrogen uptake, and criteria pollutants emitted from distributed and centralized hydrogen production pathways and their impacts on human health, air quality, ecosystems, and structures under different penetration scenarios

Wuebbles, D.J.; Dubey, M.K., Edmonds, J.; Layzell, D.; Olsen, S.; Rahn, T.; Rocket, A.; Wang, D.; Jia, W.

2010-06-01T23:59:59.000Z

272

Water-dispersible soil particles and the transport of nonpoint-source pollutants in the lower Rio Grande Valley  

E-Print Network (OSTI)

The transport of nonpoint-source pollutants in surface runoff may be enhanced through sorption to mobile soil particles, a process known as particle-mediated transport. In order to predict the potential importance of this process, the major geochemical and mineralogical factors controlling particle dispersion and pollutant sorption must be identified. These factors were determined through characterization of water-dispersible clay (WDC) assumed to be an analog of natural mobile particles. WDC were obtained from three soils representative of the lower Rio Grande Valley by dispersion in water. WDC content of the three soils varied between 5 to 15%. WDC was proportional to clay content and inversely proportional to CaCO3 content. Relative to the bulk soils characteristics, WDC was enriched in organic matter (OM), CaCO3, and Fe oxides. The presence of amorphous coatings of OM, silica, and carbonates influenced the surface chemistry and dispersion of phyrosilicate minerals in WDC. Sequential extraction of WDC, using Na-acetate (pH=5), H202 and citrate-dithionate-bicarbonate extractants, generated particles of higher surface area (an increase from 63 to 1 18 and 127 m2/g, respectively), more negative electrophoretic mobility (an increase from-2.5 to-3.5 and-4.2 um/s/m/V, respectively), and higher critical coagulation concentration (an increase from 8 to 12 and 14 meq/L, respectively). An increase in particle dispersivity upon action of the extractants was visible on Transmission Electron Microscope micrographs. Batch sorption experiments were conducted using bulk soils samples and WDC (untreated, OM removed, OM and Fe oxides removed) reacting with Zn and Cu (model metals) and pyrene (model hydrophobic organic). Higher amounts of metals were sorbed by WDC than bulk soils, the maximum enrichment ratios were 1.45 and 3.3 for Cu and Zn, respectively. The removal of OM, Fe oxides and amorphous coatings rendered the WDC material less reactive towards Zn and Cu. Metal sorption was controlled by solution pH, cation exchange capacity of the mineral phases, and the OM content. Sorption of pyrene (Koc=24290) was controlled by organic matter and followed a linear isotherm.

Przepiora, Andrzej

1995-01-01T23:59:59.000Z

273

Erosion and Optimal Transport  

E-Print Network (OSTI)

383 pp. EROSION AND OPTIMAL TRANSPORT [23] I. Ekeland and T.and D. Simons, Sediment transport capacity of overland ?ow,measure spaces via optimal transport, Ann. of Math. (2),

Birnir, Bjorn; Rowlett, Julie

2010-01-01T23:59:59.000Z

274

Reactive Power Measurement Using the Wavelet Transform  

E-Print Network (OSTI)

Abstract—This paper provides the theoretical basis for the measurement of reactive and distortion powers from the wavelet transforms. The measurement of reactive power relies on the use of broad-band phase-shift networks to create concurrent in-phase currents and quadrature voltages. The wavelet real power computation resulting from these 90 phase-shift networks yields the reactive power associated with each wavelet frequency level or subband. The distortion power at each wavelet subband is then derived from the real, reactive and apparent powers of the subband, where the apparent power is the product of the v; i element pair's subband rms voltage and current. The advantage of viewing the real and reactive powers in the wavelet domain is that the domain preserves both the frequency and time relationship of these powers. In addition, the reactive power associated with each wavelet subband is a signed quantity and thus has a direction associated with it. This permits tracking the reactive power flow in each subband through the power system. Index Terms—Digital signal processing, phase shift networks, measurement, power, RMS, subband, wavelets. I.

Weon-ki Yoon; Michael J. Devaney

2000-01-01T23:59:59.000Z

275

Comparison of biomass and coal char reactivities  

SciTech Connect

Char combustion is typically the rate limiting step during the combustion of solid fuels. The magnitude and variation of char reactivity during combustion are, therefore, of primary concern when comparing solid fuels such as coal and biomass. In an effort to evaluate biomass` potential as a sustainable and renewable energy source, the reactivities of both biomass and coal chars were compared using Sandia`s Captive Particle Imaging (CPI) apparatus. This paper summarizes the experimental approach used to determine biomass and coal reactivities and presents results from CPT experiments. The reactivity of six types of char particles, two high-rank coal chars, two low-rank coal chars, and two biomass chars, were investigated using the CPT apparatus. Results indicate that both of the high-rank coal chars have relatively low reactivities when compared with the higher reactivities measured for the low-rank coal and the biomass chars. In addition, extinction behavior of the chars support related investigations that suggest carbonaceous structural ordering is an important consideration in understanding particle reactivity as a function of extent of burnout. High-rank coal chars were found to have highly ordered carbon structures, where as, both low-rank coal and biomass chars were found to have highly disordered carbon structures.

Huey, S.P. [Sandia National Labs., Livermore, CA (United States); Davis, K.A. [Reaction Engineering International, Salt Lake City, UT (United States); Hurt, R.H. [Brown Univ., Providence, RI (United States). Div. of Engineering

1995-08-01T23:59:59.000Z

276

Systematic approach for chemical reactivity evaluation  

E-Print Network (OSTI)

Under certain conditions, reactive chemicals may proceed into uncontrolled chemical reaction pathways with rapid and significant increases in temperature, pressure, and/or gas evolution. Reactive chemicals have been involved in many industrial incidents, and have harmed people, property, and the environment. Evaluation of reactive chemical hazards is critical to design and operate safer chemical plant processes. Much effort is needed for experimental techniques, mainly calorimetric analysis, to measure thermal reactivity of chemical systems. Studying all the various reaction pathways experimentally however is very expensive and time consuming. Therefore, it is essential to employ simplified screening tools and other methods to reduce the number of experiments and to identify the most energetic pathways. A systematic approach is presented for the evaluation of reactive chemical hazards. This approach is based on a combination of computational methods, correlations, and experimental thermal analysis techniques. The presented approach will help to focus the experimental work to the most hazardous reaction scenarios with a better understanding of the reactive system chemistry. Computational methods are used to predict reaction stoichiometries, thermodynamics, and kinetics, which then are used to exclude thermodynamically infeasible and non-hazardous reaction pathways. Computational methods included: (1) molecular group contribution methods, (2) computational quantum chemistry methods, and (3) correlations based on thermodynamic-energy relationships. The experimental techniques are used to evaluate the most energetic systems for more accurate thermodynamic and kinetics parameters, or to replace inadequate numerical methods. The Reactive System Screening Tool (RSST) and the Automatic Pressure Tracking Adiabatic Calorimeter (APTAC) were employed to evaluate the reactive systems experimentally. The RSST detected exothermic behavior and measured the overall liberated energy. The APTAC simulated near-adiabatic runaway scenarios for more accurate thermodynamic and kinetic parameters. The validity of this approach was investigated through the evaluation of potentially hazardous reactive systems, including decomposition of di-tert-butyl peroxide, copolymerization of styrene-acrylonitrile, and polymerization of 1,3-butadiene.

Aldeeb, Abdulrehman Ahmed

2003-12-01T23:59:59.000Z

277

Transportation Market Distortions  

E-Print Network (OSTI)

Transport Prices and Markets, Victoria Transport PolicySurvey: Survey Suggests Market-Based Vision of Smart Growth,G. 1996. Roads in a Market Economy, Avebury (Aldershot).

Litman, Todd

2006-01-01T23:59:59.000Z

278

Sustainability and Transport  

E-Print Network (OSTI)

2005. Integrating Sustainability into the Trans- portationTHOUGHT PIECE Sustainability and Transport by Richardof the concept of sustainability to transport planning. In

Gilbert, Richard

2006-01-01T23:59:59.000Z

279

Transportation Demand This  

Annual Energy Outlook 2012 (EIA)

69 U.S. Energy Information Administration | Assumptions to the Annual Energy Outlook 2012 Transportation Demand Module The NEMS Transportation Demand Module estimates...

280

Transportation / Field Trips  

Science Conference Proceedings (OSTI)

... In the event that a child misses the transportation, parents may choose the ... their child's class on an outing and possibly transport themselves or their ...

2010-10-05T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

PBA Transportation Websites  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Websites for Transportation from PBA From: Patterson, Philip (DOE HQ) Subject: Useful Websites for Transportation from PBA Here are some websites you might want to check...

282

COAL SLAGGING AND REACTIVITY TESTING  

SciTech Connect

Union Fenosa's La Robla I Power Station is a 270-MW Foster Wheeler arch-fired system. The unit is located at the mine that provides a portion of the semianthracitic coal. The remaining coals used are from South Africa, Russia, Australia, and China. The challenges at the La Robla I Station stem from the various fuels used, the characteristics of which differ from the design coal. The University of North Dakota Energy & Environmental Research Center (EERC) and the Lehigh University Energy Research Center (LUERC) undertook a program to assess problematic slagging and unburned carbon issues occurring at the plant. Full-scale combustion tests were performed under baseline conditions, with elevated oxygen level and with redistribution of air during a site visit at the plant. During these tests, operating information, observations and temperature measurements, and coal, slag deposit, and fly ash samples were obtained to assess slagging and unburned carbon. The slagging in almost all cases appeared due to elevated temperatures rather than fuel chemistry. The most severe slagging occurred when the temperature at the sampling port was in excess of 1500 C, with problematic slagging where first-observed temperatures exceeded 1350 C. The presence of anorthite crystals in the bulk of the deposits analyzed indicates that the temperatures were in excess of 1350 C, consistent with temperature measurements during the sampling period. Elevated temperatures and ''hot spots'' are probably the result of poor mill performance, and a poor distribution of the coal from the mills to the specific burners causes elevated temperatures in the regions where the slag samples were extracted. A contributing cause appeared to be poor combustion air mixing and heating, resulting in oxygen stratification and increased temperatures in certain areas. Air preheater plugging was observed and reduces the temperature of the air in the windbox, which leads to poor combustion conditions, resulting in unburned carbon as well as slagging. A second phase of the project involved advanced analysis of the baseline coal along with an Australian coal fired at the plant. These analysis results were used in equilibrium thermodynamic modeling along with a coal quality model developed by the EERC to assess slagging, fouling, and opacity for the coals. Bench-scale carbon conversion testing was performed in a drop-tube furnace to assess the reactivity of the coals. The Australian coal had a higher mineral content with significantly more clay minerals present than the baseline coal. The presence of these clay minerals, which tend to melt at relatively low temperatures, indicated a higher potential for problematic slagging than the baseline coal. However, the pyritic minerals, comprising over 25% of the baseline mineral content, may form sticky iron sulfides, leading to severe slagging in the burner region if local areas with reducing conditions exist. Modeling results indicated that neither would present significant fouling problems. The Australian coal was expected to show slagging behavior much more severe than the baseline coal except at very high furnace temperatures. However, the baseline coal was predicted to exhibit opacity problems, as well as have a higher potential for problematic calcium sulfate-based low-temperature fouling. The baseline coal had a somewhat higher reactivity than the Australian coal, which was consistent with both the lower average activation energy for the baseline coal and the greater carbon conversion at a given temperature and residence time. The activation energy of the baseline coal showed some effect of oxygen on the activation energy, with E{sub a} increasing at the lower oxygen concentration, but may be due to the scatter in the baseline coal kinetic values at the higher oxygen level tested.

Donald P. McCollor; Kurt E. Eylands; Jason D. Laumb

2003-10-01T23:59:59.000Z

283

Geological, geochemical, and geophysical survey of the geothermal resources at Hot Springs Bay Valley, Akutan Island, Alaska  

DOE Green Energy (OSTI)

An extensive survey was conducted of the geothermal resource potential of Hot Springs Bay Valley on Akutan Island. A topographic base map was constructed, geologic mapping, geophysical and geochemical surveys were conducted, and the thermal waters and fumarolic gases were analyzed for major and minor element species and stable isotope composition. (ACR)

Motyka, R.J.; Wescott, E.M.; Turner, D.L.; Swanson, S.E.; Romick, J.D.; Moorman, M.A.; Poreda, R.J.; Witte, W.; Petzinger, B.; Allely, R.D.

1985-01-01T23:59:59.000Z

284

Geochemical records in the South China Sea: implications for East Asian summer monsoon evolution over the last 20 Ma  

E-Print Network (OSTI)

Geochemical records in the South China Sea: implications for East Asian summer monsoon evolution past changes in the East Asian summer monsoon over the last 20 Ma using samples from Ocean Drilling and combined review suggests that the long-term evolution of the East Asian summer monsoon is similar

Clift, Peter

285

Geochemical Data on Waters, gases, scales, and rocks from the Dixie Valley Region, Nevada (1996-1999)  

DOE Green Energy (OSTI)

This report tabulates an extensive geochemical database on waters, gases, scales, rocks, and hot-spring deposits from the Dixie Valley region, Nevada. The samples from which the data were obtained were collected and analyzed during 1996 to 1999. These data provide useful information for ongoing and future investigations on geothermal energy, volcanism, ore deposits, environmental issues, and groundwater quality in this region.

Goff, Fraser; Bergfeld, Deborah; Janik, C.J.; et al

2002-08-01T23:59:59.000Z

286

VOLTINT: A Matlab®-based program for semi-automated processing of geochemical data acquired by voltammetry  

Science Conference Proceedings (OSTI)

Recent progress has resulted in the development of advanced techniques to acquire geochemical information in situ in aquatic systems. Among these techniques, voltammetry has generated significant interest for its ability to detect several important redox-sensitive ... Keywords: Data processing, Geochemistry, Integration, Matlab®, Software, Voltammetry

Gwendolyn Bristow; Martial Taillefert

2008-02-01T23:59:59.000Z

287

Conservative numerical simulation of multi-component transport in two-dimensional unsteady shallow water flow  

Science Conference Proceedings (OSTI)

An explicit finite volume model to simulate two-dimensional shallow water flow with multi-component transport is presented. The governing system of coupled conservation laws demands numerical techniques to avoid unrealistic values of the transported ... Keywords: ?-? model, 35L65, 65M06, 65M12, 76M12, 76M20, Coupled system, Multi-component transport, Reactive source terms, Shallow flow, Solute constraints, Turbulence, Variable domain, Well-balanced approach

J. Murillo; P. García-Navarro; J. Burguete

2009-08-01T23:59:59.000Z

288

Final Report Phase II: Performance Evaluation of Permeable Reactive  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical

289

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium Mill Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium

290

Efficient and Reliable Reactive Power Supply and Consumption...  

NLE Websites -- All DOE Office Websites (Extended Search)

Efficient and Reliable Reactive Power Supply and Consumption - Insights from an Integrated Program of Engineering and Economics Research Title Efficient and Reliable Reactive Power...

291

Olefin production via reactive distillation based Olefin metathesis.  

E-Print Network (OSTI)

??Reactive distillation is a combination of a traditional multi-stage distillation column with a chemical reaction. The primary benefits of a reactive distillation process are reduced… (more)

Morrison, Ryan Frederick

2012-01-01T23:59:59.000Z

292

A Parametric Reactive Distillation Study: Economic Feasibility and Design Heuristics.  

E-Print Network (OSTI)

??The integration of reaction and distillation into a single column is called reactive distillation or catalytic distillation. Reactive distillation provides many benefits such as reduced… (more)

Hoyme, Craig Alan

2004-01-01T23:59:59.000Z

293

Observations on the Coke Air Reactivity Test - Programmaster.org  

Science Conference Proceedings (OSTI)

Coke air reactivities are strongly dependent on coke calcination levels and it is possible to drive air reactivities lower by increasing calcining temperatures.

294

CHEPROO: A Fortran 90 object-oriented module to solve chemical processes in Earth Science models  

Science Conference Proceedings (OSTI)

Accurate prediction of contaminant migration in surface and ground water bodies, including interaction with aquifer and hyporheic zone materials requires reactive transport modeling. The increasing complexity and the procedure-oriented type of programming ... Keywords: Fortran 90, Geochemical modeling, Object-oriented programming, Reactive transport

S. A. Bea; J. Carrera; C. Ayora; F. Batlle; M. W. Saaltink

2009-06-01T23:59:59.000Z

295

Workshop on hydrologic and geochemical monitoring in the Long Valley Caldera: proceedings  

DOE Green Energy (OSTI)

A workshop reviewed the results of hydrologic and geochemical monitoring in the Long Valley caldera. Such monitoring is being done to detect changes in the hydrothermal system induced by ongoing magmatic and tectonic processes. Workshop participants discussed the need to instrument sites for continuous measurements of several parameters and to obtain additional hydrologic and chemical information from intermediate and deep drill holes. In addition to seismic and deformation monitoring, programs are currently in progress to monitor changes in the discharge characteristics of hot springs, fumaroles, and soil gases, as well as pressures and temperatures in wells. Some hydrochemical parameters are measured continuously, others are measured monthly or at longer intervals. This report summarizes the information presented at the hydrologic monitoring workshop, following the workshop agenda which was divided into four sessions: (1) overview of the hydrothermal system; (2) monitoring springs, fumaroles, and wells; (3) monitoring gas emissions; and (4) conclusions and recommendations.

Sorey, M.L.; Farrar, C.D.; Wollenberg, H.A.

1984-10-01T23:59:59.000Z

296

Reactivity control assembly for nuclear reactor  

DOE Patents (OSTI)

Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.

Bollinger, Lawrence R. (Schenectady, NY)

1984-01-01T23:59:59.000Z

297

A Tariff for Reactive Power - IEEE  

DOE Green Energy (OSTI)

This paper describes a suggested tariff or payment for the local supply of reactive power from distributed energy resources. The authors consider four sample customers, and estimate the cost of supply of reactive power for each customer. The power system savings from the local supply of reactive power are also estimated for a hypothetical circuit. It is found that reactive power for local voltage regulation could be supplied to the distribution system economically by customers when new inverters are installed. The inverter would be supplied with a power factor of 0.8, and would be capable of local voltage regulation to a schedule supplied by the utility. Inverters are now installed with photovoltaic systems, fuel cells and microturbines, and adjustable-speed motor drives.

Kueck, John D [ORNL; Tufon, Christopher [Pacific Gas and Electric Company; Isemonger, Alan [California Independent System Operator; Kirby, Brendan J [ORNL

2008-11-01T23:59:59.000Z

298

Mild coal pretreatment to improve liquefaction reactivity  

SciTech Connect

This report describes work completed during the fourth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. This work is part of a larger effort to develop a new coal liquefaction or coal/oil coprocessing scheme consisting of three main process steps: (1) mile pretreatment of the feed coal to enhance dissolution reactivity and dry the coal, (2) low severity thermal dissolution of the pretreated coal to obtain a very reactive coal-derived residual material amenable to upgrading, and (3) catalytic upgrading of the residual products to distillate liquids.

Miller, R.L.

1991-01-01T23:59:59.000Z

299

Groundwater well with reactive filter pack  

DOE Patents (OSTI)

A method and apparatus for the remediation of contaminated soil and ground water wherein a reactive pack material is added to the annular fill material utilized in standard well construction techniques.

Gilmore, Tyler J. (Pasco, WA); Holdren, Jr., George R. (Kennewick, WA); Kaplan, Daniel I. (Richland, WA)

1998-01-01T23:59:59.000Z

300

Fossil plant layup and reactivation conference: Proceedings  

Science Conference Proceedings (OSTI)

The Fossil Plant Layup and Reactivation Conference was held in New Orleans, Louisiana on April 14--15, 1992. The Conference was sponsored by EPRI and hosted by Entergy Services, Inc. to bring together representatives from utilities, consulting firms, manufacturers and architectural engineers. Eighteen papers were presented in three sessions. These sessions were devoted to layup procedures and practices, and reactivation case studies. A panel discussion was held on the second day to interactively discuss layup and reactivation issues. More than 80 people attended the Conference. This report contains technical papers and a summary of the panel discussion. Of the eighteen papers, three are related to general, one is related to regulatory issues, three are related to specific equipment, four are related to layup procedures and practices, and seven are layup and reactivation case studies.

Not Available

1992-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Oxidation Resistance of Reactive Atoms in Graphene  

SciTech Connect

We have found that reactive elements that are normally oxidized at room temperature are present as individual atoms or clusters on and in graphene. Oxygen is present in these samples but it is only detected in the thicker amorphous carbon layers present in the graphene specimens we have examined. However, we have seen no evidence that oxygen reacts with the impurity atoms and small clusters of these normally reactive elements when they are incorporated in the graphene layers. First principles calculations suggest that the oxidation resistance is due to kinetic effects such as preferential bonding of oxygen to nonincorporated atoms and H passivation. The observed oxidation resistance of reactive atoms in graphene may allow the use of these incorporated metals in catalytic applications. It also opens the possibility of designing and producing electronic, opto-electronic, and magnetic devices based on these normally reactive atoms.

Chisholm, Matthew F [ORNL; Duscher, Gerd [University of Tennessee, Knoxville (UTK); Windl, Wolfgang [Ohio State University

2012-01-01T23:59:59.000Z

302

Radiative Forcing Due to Reactive Gas Emissions  

Science Conference Proceedings (OSTI)

Reactive gas emissions (CO, NOx, VOC) have indirect radiative forcing effects through their influences on tropospheric ozone and on the lifetimes of methane and hydrogenated halocarbons. These effects are quantified here for the full set of ...

T. M. L. Wigley; S. J. Smith; M. J. Prather

2002-09-01T23:59:59.000Z

303

Hydrogeochemical and stream sediment detailed geochemical survey for Edgemont, South Dakota; Wyoming  

SciTech Connect

Results of the Edgemont detailed geochemical survey are reported. Field and laboratory data are presented for 109 groundwater and 419 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are given. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwaters containing greater than or equal to 7.35 ppB uranium are present in scattered clusters throughout the area sampled. Most of these groundwaters are from wells drilled where the Inyan Kara Group is exposed at the surface. The exceptions are a group of samples in the northwestern part of the area sampled and south of the Dewey Terrace. These groundwaters are also produced from the Inyan Kara Group where it is overlain by the Graneros Group and alluvium. The high uranium groundwaters along and to the south of the terrace are characterized by high molybdenum, uranium/specific conductance, and uranium/sulfate values. Many of the groundwaters sampled along the outcrop of the Inyan Kara Group are near uranium mines. Groundwaters have high amounts of uranium and molybdenum. Samples taken downdip are sulfide waters with low values of uranium and high values of arsenic, molybdenum, selenium, and vanadium. Stream sediments containing greater than or equal to 5.50 ppM soluble uranium are concentrated in basins draining the Graneros and Inyan Kara Groups. These values are associated with high values for arsenic, selenium, and vanadium in samples from both groups. Anomalous values for these elements in the Graneros Group may be caused by bentonite beds contained in the rock units. As shown on the geochemical distribution plot, high uranium values that are located in the Inyan Kara Group are almost exclusively draining open-pit uranium mines.

Butz, T.R.; Dean, N.E.; Bard, C.S.; Helgerson, R.N.; Grimes, J.G.; Pritz, P.M.

1980-05-31T23:59:59.000Z

304

Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine  

SciTech Connect

Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed.

Hamaguchi, Satoshi [Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2013-07-11T23:59:59.000Z

305

MSTS - Multiphase Subsurface Transport Simulator theory manual  

SciTech Connect

The US Department of Energy, through the Yucca Mountain Site Characterization Project Office, has designated the Yucca Mountain site in Nevada for detailed study as the candidate US geologic repository for spent nuclear fuel and high-level radioactive waste. Site characterization will determine the suitability of the Yucca Mountain site for the potential waste repository. If the site is determined suitable, subsequent studies and characterization will be conducted to obtain authorization from the Nuclear Regulatory Commission to construct the potential waste repository. A principal component of the characterization and licensing processes involves numerically predicting the thermal and hydrologic response of the subsurface environment of the Yucca Mountain site to the potential repository over a 10,000-year period. The thermal and hydrologic response of the subsurface environment to the repository is anticipated to include complex processes of countercurrent vapor and liquid migration, multiple-phase heat transfer, multiple-phase transport, and geochemical reactions. Numerical simulators based on mathematical descriptions of these subsurface phenomena are required to make numerical predictions of the thermal and hydrologic response of the Yucca Mountain subsurface environment The engineering simulator called the Multiphase Subsurface Transport Simulator (MSTS) was developed at the request of the Yucca Mountain Site Characterization Project Office to produce numerical predictions of subsurface flow and transport phenomena at the potential Yucca Mountain site. This document delineates the design architecture and describes the specific computational algorithms that compose MSTS. Details for using MSTS and sample problems are given in the {open_quotes}User`s Guide and Reference{close_quotes} companion document.

White, M.D.; Nichols, W.E.

1993-05-01T23:59:59.000Z

306

Preclosure Monitoring and Performance Confirmation at Yucca Mountain: Applicability of Geophysical, Geohydrological, and Geochemical Methods  

E-Print Network (OSTI)

Crilical Parameters Radionuclide Concentration Liquid/Gasin Table 1, includes radionuclide concentration, liquid/gasbe the means by which radionuclides could be transported to

Tsang, C.F.

2010-01-01T23:59:59.000Z

307

Graduate Certificate in Transportation  

E-Print Network (OSTI)

Graduate Certificate in Transportation Nohad A. Toulan School of Urban Studies and Planning of Engineering and Computer Science integrated transportation systems. The Graduate Certificate in Transportation their capabilities. Students in the program can choose among a wide range of relevant courses in transportation

Bertini, Robert L.

308

TRANSPORTATION Annual Report  

E-Print Network (OSTI)

and educate the future transportation workforce. An example of what we can accomplish is shown2003 CENTER FOR TRANSPORTATION STUDIES Annual Report #12;Center for Transportation Studies University of Minnesota 200 Transportation and Safety Building 511 Washington Avenue S.E. Minneapolis, MN

Minnesota, University of

309

Transportation Organization and Functions  

Energy.gov (U.S. Department of Energy (DOE))

Office of Packaging and Transportation list of organizations and functions, with a list of acronyms.

310

Enhanced Oxidative Reactivity for Anthracite Coal via a Reactive Ball Milling Pretreatment Step  

Science Conference Proceedings (OSTI)

Reactive ball milling in a cyclohexene solvent significantly increases the oxidative reactivity of an anthracite coal, due to the combined effects of particle size reduction, metal introduction, introduction of volatile matter, and changes in carbon structure. Metals introduced during milling can be easily removed via a subsequent demineralization process, and the increased reactivity is retained. Solvent addition alters the morphological changes that occur during pyrolysis and leads to a char with significantly increased reactivity. When the solvent is omitted, similar effects are seen for the milled product, but a significant fraction of the char is resistant to oxidation. 33 refs., 3 figs., 1 tab.

Angela D. Lueking; Apurba Sakti; Dania Alvarez-Fonseca; Nichole Wonderling [Pennsylvania State University, PA (United States). Department of Energy and Mineral Engineering

2009-09-15T23:59:59.000Z

311

Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight pipeline transportation > Airport planning and development > Airport maintenance > Bicycle and pedes  

E-Print Network (OSTI)

Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight pipeline transportation > Airport planning and development > Airport maintenance > Bicycle and pedestrian > Ports and waterways >>> Transportation operat

312

Understanding Long-Term Solute Transport in Sedimentary Basins: Simulating Brine Migration in the Alberta Basin. Final Report  

Science Conference Proceedings (OSTI)

Mass transport in deep sedimentary basins places important controls on ore formation, petroleum migration, CO2 sequestration, and geochemical reactions that affect petroleum reservoir quality, but large-scale transport in this type of setting remains poorly understood. This lack of knowledge is highlighted in the resource-rich Alberta Basin, where geochemical and hydrogeologic studies have suggested residence times ranging from hundreds of millions of years to less than 5 My, respectively. Here we developed new hydrogeologic models that were constrained by geochemical observations to reconcile these two very different estimates. The models account for variable-density fluid flow, heat transport, solute transport, sediment deposition and erosion, sediment compressibility, and dissolution of salt deposits, including Cl/Br systematics. Prior interpretations of Cl/Br ratios in the Alberta Basin concluded that the brines were derived from evaporatively-concentrated brines that were subsequently diluted by seawater and freshwater; models presented here show that halite dissolution must have contributed strongly as well, which implies significantly greater rates of mass transport. This result confirms that Cl/Br ratios are subject to significant non-uniqueness and thus do not provide good independent indicators of the origin of brines. Salinity and Cl/Br ratios provided valuable new constraints for basin-scale models, however. Sensitivity studies revealed that permeabilities obtained from core- and field-scale tests were appropriate for basin-scale models, despite the differences in scale between the tests and the models. Simulations of groundwater age show that the residence time of porefluids in much of the basin is less than 100 My. Groundwater age increases with depth and approaches 200 My in the deepest part of the basin, but brines are significantly younger than their host rocks throughout the basin.

Alicia M. Wilson

2009-11-30T23:59:59.000Z

313

review of extraction, processing, properties & applications of reactive ...  

Science Conference Proceedings (OSTI)

REVIEW OF EXTRACTION,. PROCESSING, PROPERTIES. & APPLICATIONS OF. REACTIVE METALS. Edited by. Brajendra Mishra ...

314

Transportation Planning & Decision Science Group Transportation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Award on January 16, 2013, during the Chairman's Luncheon at the 92nd Annual Transportation Research Board (TRB) Meeting in Washington, DC. Dr. Greene was honored for his...

315

Final Report Phase II: Performance Evaluation of Permeable Reactive  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Final Report Phase II: Performance Evaluation of Permeable Reactive Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report - Rejuvenating Permeable Reactive Barriers by Chemical Flushing, U.S. Environmental Protection Agency Region 8 Support

316

Phase II: Performance Evaluation of Permeable Reactive Barriers and  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Phase II: Performance Evaluation of Permeable Reactive Barriers and Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing U. S. Environmental Protection Agency Region 8 Support January 2004 Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing More Documents & Publications Final Report Phase II: Performance Evaluation of Permeable Reactive Barriers and Potential for Rejuvenation by Chemical Flushing Rejuvenating Permeable Reactive Barriers by Chemical Flushing

317

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Hydraulic Conductivity of the Monticello Permeable Reactive Barrier Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update Hydraulic Conductivity of the Monticello Permeable Reactive Barrier November 2005 Update More Documents & Publications Variation in Hydraulic Conductivity Over Time at the Monticello Permeable Reactive Barrier Ground-Water Table and Chemical Changes in an Alluvial Aquifer During Sustained Pumping at the Monticello, Utah, Zero-Valent Iron Treatment Cells Performance Assessment and Recommendations for Rejuvenation of a Permeable Reactive Barrier: Cotter Corporation's Cañon City, Colorado, Uranium

318

Alternative Transportation ExpoAlternative Transportation ExpoAlternative Transportation Expo SPONSORED BY  

E-Print Network (OSTI)

Alternative Transportation ExpoAlternative Transportation ExpoAlternative Transportation Expo providers,Exhibits and vehicles from auto manufacturers, energy providers, entrepreneurs, transportation providers, and an art contest.entrepreneurs, transportation providers, and an art contest

de Lijser, Peter

319

Transportation | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Transportation Power Electronics and Electric Machinery Fuels, Engines, Emissions Transportation Analysis Vehicle Systems Energy Storage Propulsion Materials Lightweight Materials Bioenergy Fuel Cell Technologies Clean Energy Home | Science & Discovery | Clean Energy | Research Areas | Transportation SHARE Transportation Research ORNL researcher Jim Szybist uses a variable valve-train engine to evaluate different types of fuels, including ethanol blends, and their effects on the combustion process in an internal combustion engine. Oak Ridge National Laboratory brings together science and technology experts from across scientific disciplines to partner with government and industry in addressing transportation challenges. Research objectives are

320

Analysis of Mineral Trapping for CO2 Disposal in Deep Aquifers  

Office of Scientific and Technical Information (OSTI)

Reactive Geochemical Transport Simulation to Study Mineral Trapping Reactive Geochemical Transport Simulation to Study Mineral Trapping for CO 2 Disposal in Deep Saline Arenaceous Aquifers Tianfu Xu, John A. Apps, and Karsten Pruess Earth Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA Abstract. A reactive fluid flow and geochemical transport numerical model for evaluating long-term CO 2 disposal in deep aquifers has been developed. Using this model, we performed a number of sensitivity simulations under CO 2 injection conditions for a commonly encountered Gulf Coast sediment to analyze the impact of CO 2 immobilization through carbonate precipitation. Geochemical models are needed because alteration of the predominant host rock aluminosilicate minerals is very slow and is not

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Local Transportation Sales Taxes: California's Experiment in Transportation Finance  

E-Print Network (OSTI)

Section 131051, “County Transportation Expenditure Plans. ”Fresno County Transportation Authority, Annual Report (1994-D.A. Niemeier, “Comparing Transportation Project Development

Crabbe, Amber E.; Hiatt, Rachel; Poliwka, Susan D.; Wachs, Martin

2005-01-01T23:59:59.000Z

322

Geologic, geophysical, and geochemical aspects of site-specific studies of the geopressured-geothermal energy resource of southern Louisiana. Final report  

DOE Green Energy (OSTI)

The report consists of four sections dealing with progress in evaluating geologic, geochemical, and geophysical aspects of geopressured-geothermal energy resources in Louisiana. Separate abstracts have been prepared for the individual sections. (ACR)

Pilger, R.H. Jr. (ed.)

1985-01-01T23:59:59.000Z

323

Performance Assessment Transport Modeling of Uranium at the Area 5 Radioactive Waste Management Site at the Nevada National Security Site  

SciTech Connect

Following is a brief summary of the assumptions that are pertinent to the radioactive isotope transport in the GoldSim Performance Assessment model of the Area 5 Radioactive Waste Management Site, with special emphasis on the water-phase reactive transport of uranium, which includes depleted uranium products.

NSTec Radioactive Waste

2010-10-12T23:59:59.000Z

324

Core-based integrated sedimentologic, stratigraphic, and geochemical analysis of the oil shale bearing Green River Formation, Uinta Basin, Utah  

NLE Websites -- All DOE Office Websites (Extended Search)

DOE Award No.: DE-FE0001243 DOE Award No.: DE-FE0001243 Topical Report CORE-BASED INTEGRATED SEDIMENTOLOGIC, STRATIGRAPHIC, AND GEOCHEMICAL ANALYSIS OF THE OIL SHALE BEARING GREEN RIVER FORMATION, UINTA BASIN, UTAH Submitted by: University of Utah Institute for Clean and Secure Energy 155 South 1452 East, Room 380 Salt Lake City, UT 84112 Prepared for: United States Department of Energy National Energy Technology Laboratory April 2011 Oil & Natural Gas Technology Office of Fossil Energy Core-based integrated sedimentologic, stratigraphic, and geochemical analysis of the oil shale bearing Green River Formation, Uinta Basin, Utah Topical Report Reporting Period: October 31, 2009 through March 31, 2011 Authors: Lauren P. Birgenheier, Energy and Geoscience Insitute, University of Utah

325

Nuclear engine flow reactivity shim control  

DOE Patents (OSTI)

A nuclear engine control system is provided which automatically compensates for reactor reactivity uncertainties at the start of life and reactivity losses due to core corrosion during the reactor life in gas-cooled reactors. The coolant gas flow is varied automatically by means of specially provided control apparatus so that the reactor control drums maintain a predetermined steady state position throughout the reactor life. This permits the reactor to be designed for a constant drum position and results in a desirable, relatively flat temperature profile across the core. (Official Gazette)

Walsh, J.M.

1973-12-11T23:59:59.000Z

326

Transportation risk assessment for ethanol transport  

E-Print Network (OSTI)

This research is aimed at assessing the quantitative risks involved with an ethanol pipeline. Pipelines that run from the Midwest, where the vast majority of ethanol is produced, to the target areas where reformulated gasoline is required (California, Texas Gulf Coast, New England Atlantic Coast) will be of particular interest. The goal is to conduct a quantitative risk assessment on the pipeline, truck, and rail transportation modes to these areas. As a result of the quantitative risk assessment, we are able to compare the risk associated with the different modes of transportation for ethanol. In order to perform and compare the quantitative risk assessment, the following challenges are addressed: 1) Identify target areas requiring reformulated gasoline 2) Map detailed route for each transportation mode to all three target areas 3) Perform a quantitative risk assessment for each transportation mode 4) Compare quantitative risk assessment results for each route and transportation mode The focus is on California, Texas Gulf Coast, and New England Atlantic Coast because of the large volume. It is beneficial to look at these areas as opposed to the smaller areas because pipeline transportation requires very large volumes. In order to find a meaningful comparison between all three transportation modes, only the areas with the three large volumes were evaluated. Since the risk assessment is completed using historical data, each route is segmented in a way that is consistent with the data that is available. All of the curves support the hypothesis that pipeline transportation poses the least societal risk when transporting ethanol from the Midwest to target areas. Rail transportation poses the largest amount of societal risk. While overall rail incidents are not as frequent as road incidents, the frequency of a fatality is much higher when an incident does occur.

Shelton Davis, Anecia Delaine

2007-12-01T23:59:59.000Z

327

Transportation risk assessment for ethanol transport  

E-Print Network (OSTI)

This research is aimed at assessing the quantitative risks involved with an ethanol pipeline. Pipelines that run from the Midwest, where the vast majority of ethanol is produced, to the target areas where reformulated gasoline is required (California, Texas Gulf Coast, New England Atlantic Coast) will be of particular interest. The goal is to conduct a quantitative risk assessment on the pipeline, truck, and rail transportation modes to these areas. As a result of the quantitative risk assessment, we are able to compare the risk associated with the different modes of transportation for ethanol. In order to perform and compare the quantitative risk assessment, the following challenges are addressed: • Identify target areas requiring reformulated gasoline • Map detailed route for each transportation mode to all three target areas • Perform a quantitative risk assessment for each transportation mode • Compare quantitative risk assessment results for each route and transportation mode The focus is on California, Texas Gulf Coast, and New England Atlantic Coast because of the large volume. It is beneficial to look at these areas as opposed to the smaller areas because pipeline transportation requires very large volumes. In order to find a meaningful comparison between all three transportation modes, only the areas with the three large volumes were evaluated. Since the risk assessment is completed using historical data, each route is segmented in a way that is consistent with the data that is available. All of the curves support the hypothesis that pipeline transportation poses the least societal risk when transporting ethanol from the Midwest to target areas. Rail transportation poses the largest amount of societal risk. While overall rail incidents are not as frequent as road incidents, the frequency of a fatality is much higher when an incident does occur.

Shelton Davis, Anecia Delaine

2007-12-01T23:59:59.000Z

328

Injection and Reservoir Hazard Management: Mechanical Deformation and Geochemical Alteration at the InSalah CO2 Storage Project  

NLE Websites -- All DOE Office Websites (Extended Search)

Injection and Reservoir Hazard Injection and Reservoir Hazard Management: Mechanical Deformation and Geochemical Alteration at the In Salah CO 2 Storage Project Background Safe and permanent storage of carbon dioxide (CO 2 ) in geologic reservoirs is critical to geologic sequestration. The In Salah Project (joint venture of British Petroleum (BP), Sonatrach, and StatoilHydro) has two fundamental goals: (1) 25-30 years of 9 billion cubic feet per year (bcfy) natural gas production from 8 fields in the Algerian

329

The application of PHREEQCi, a geochemical computer program, to aid in the management of a wastewater treatment wetland  

E-Print Network (OSTI)

In the past decade, constructed wetlands have become popular for treating coal-generated acid mine drainage and leachate from coal-ash disposal areas. The goal of the wetland manager is to design a system in which the pH is neutralized, toxic metals are removed, and wetland discharge meets or exceeds discharge standards for water quality. This is typically accomplished by using a combination of wetlands, ponds, and limestone drains. The treatment capability of a constructed wetland is based on relationships among dissolved oxygen (DO), pH, and metal speciation. The aim of this research was to determine if PHREEQCi, a geochemical computer program, could be used in wetland management and design. The wetland site chosen for this study was at a Texas Municipal Power Agency (TMPA) plant located in Grimes County, Texas and was created to treat leachate from a solid waste disposal area where coal ash and SO? scrubber sludge was deposited. The leachate contains significant concentrations of sulfate, chloride, total dissolved solids (TDS), arsenic, and selenium. Using PHREEQCi, geochemical speciation models were created to study the interrelationships between critical chemical components at the TMPA site in order to establish an optimum set of conditions to improve treatment capability and to avoid wetland failure. The results of the geochemical speciation modeling indicated a challenging situation for a wetland manager because different species precipitate under contrasting environments. In order to apply the geochemical speciation results to the design of the TMPA site, two conditions must be recognized. First, metal removal is best accomplished by generating alkaline and oxidative conditions to promote metal-oxide precipitation. Second, sulfate can be controlled under reducing environments where it is converted to sulfide and metal sulfides precipitate. Chlorides are very soluble and no viable conclusions as to the most appropriate removal method could be postulated. TDS has an ambiguous composition and could not be modeled using PHREEQCi.

Mitzman, Stephanie

1999-01-01T23:59:59.000Z

330

Anomalous radial transport in tokamak edge plasma  

E-Print Network (OSTI)

1.2 Transport in tokamakAnomalous radial transport model for edge plasma . . . . . .Anomalous transport . . . . . . . . . . . . . . . . . . . .

Bodi, Vasudeva Raghavendra Kowsik

2010-01-01T23:59:59.000Z

331

Midwestern Radioactive Materials Transportation Committee Agenda...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Midwestern Radioactive Materials Transportation Committee Agenda Midwestern Radioactive Materials Transportation Committee Agenda Midwestern Radioactive Materials Transportation...

332

transportation | OpenEI  

Open Energy Info (EERE)

transportation transportation Dataset Summary Description The 2009 National Household Travel Survey (NHTS) provides information to assist transportation planners and policy makers who need comprehensive data on travel and transportation patterns in the United States. The 2009 NHTS updates information gathered in the 2001 NHTS and in prior Nationwide Personal Transportation Surveys (NPTS) conducted in 1969, 1977, 1983, 1990, and 1995. Source U.S. Department of Transportation, Federal Highway Administration Date Released February 28th, 2011 (3 years ago) Date Updated Unknown Keywords NHTS TEF transportation Transportation Energy Futures travel trip Data application/zip icon Travel Day Trip File (zip, 42.6 MiB) application/zip icon Household File (zip, 5 MiB) application/zip icon Person File (zip, 17.4 MiB)

333

Linear Motor Powered Transportation  

E-Print Network (OSTI)

This special issue on linear-motor powered transportation covers both supporting technologies and innovative transport systems in various parts of the World, as this technology moves from the lab to commercial operations. ...

Thornton, Richard D.

334

Transportation Demand This  

U.S. Energy Information Administration (EIA) Indexed Site

Transportation Demand Transportation Demand This page inTenTionally lefT blank 75 U.S. Energy Information Administration | Assumptions to the Annual Energy Outlook 2013 Transportation Demand Module The NEMS Transportation Demand Module estimates transportation energy consumption across the nine Census Divisions (see Figure 5) and over ten fuel types. Each fuel type is modeled according to fuel-specific and associated technology attributes applicable by transportation mode. Total transportation energy consumption is the sum of energy use in eight transport modes: light-duty vehicles (cars and light trucks), commercial light trucks (8,501-10,000 lbs gross vehicle weight), freight trucks (>10,000 lbs gross vehicle weight), buses, freight and passenger aircraft, freight

335

Transportation Management Workshop: Proceedings  

Science Conference Proceedings (OSTI)

This report is a compilation of discussions presented at the Transportation Management Workshop held in Gaithersburg, Maryland. Topics include waste packaging, personnel training, robotics, transportation routing, certification, containers, and waste classification.

Not Available

1993-10-01T23:59:59.000Z

336

Cross-Gyre Transports  

Science Conference Proceedings (OSTI)

What is the fate of surface Ekman transport entering a subtropical gyre through its zonal boundaries? This question is investigated by resolving interior transport of a deep surface layer into nonvortical (potential flow) and nondivergent (...

G. T. Csanady

1986-10-01T23:59:59.000Z

337

WIPP Transportation (FINAL)  

NLE Websites -- All DOE Office Websites (Extended Search)

WIPP TRANSPORTATION SYSTEM Waste Isolation Pilot Plant U.S. Department Of Energy The U.S. Department of Energy (DOE) has established an elaborate system for safely transporting...

338

Transportation and its Infrastructure  

E-Print Network (OSTI)

prices and alternative transport fuels; • R&D outcomes in several areas, especially biomassprices and the economic viability of alternative transport fuels; • R&D outcomes in several areas, especially biomass

2007-01-01T23:59:59.000Z

339

Transport Properties for Combustion Modeling  

E-Print Network (OSTI)

PRACTICE FOR CALCULATING TRANSPORT PROPERTIES V. 1. T HEcases; (4) performing more transport property measurementsFOR THE CALCULATION OF TRANSPORT PROPERTIES: III. EVALUATION

Brown, N.J.

2010-01-01T23:59:59.000Z

340

Transportation Infrastructure and Sustainable Development  

E-Print Network (OSTI)

A Better Forecasting Tool for Transportation Decision-making,” Mineta Transportation Institute, San Jose Stateat the 2008 meeting of the Transportation Research Board and

Boarnet, Marlon G.

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Transportation Analysis | Clean Energy | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Analysis SHARE Transportation Analysis Transportation Analysis efforts at Oak Ridge National Laboratory contribute to the efficient, safe, and free movement of...

342

FCT Technology Validation: Transportation Projects  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Projects to someone by E-mail Share FCT Technology Validation: Transportation Projects on Facebook Tweet about FCT Technology Validation: Transportation Projects on...

343

Alteration of As-bearing Phases in a Small Watershed Located on a High Grade Arsenic-geochemical Anomaly (French Massif Central)  

SciTech Connect

At a watershed scale, sediments and soil weathering exerts a control on solid and dissolved transport of trace elements in surface waters and it can be considered as a source of pollution. The studied subwatershed (1.5 km{sup 2}) was located on an As-geochemical anomaly. The studied soil profile showed a significant decrease of As content from 1500 mg kg{sup -1} in the 135-165 cm deepest soil layer to 385 mg kg{sup -1} in the upper 0-5 cm soil layer. Directly in the stream, suspended matter and the <63 {micro}m fraction of bed sediments had As concentrations greater than 400 mg kg{sup -1}. In all these solid fractions, the main representative As-bearing phases were determined at two different observation scales: bulk analyses using X-ray absorption structure spectroscopy (XAS) and microanalyses using scanning electron microscope (SEM) and associated electron probe microanalyses (EPMA), as well as micro-Raman spectroscopy and synchrotron-based micro-scanning X-ray diffraction ({micro}SXRD) characterization. Three main As-bearing phases were identified: (i) arsenates (mostly pharmacosiderite), the most concentrated phases As in both the coherent weathered bedrock and the 135-165 cm soil layer but not observed in the river solid fraction, (ii) Fe-oxyhydroxides with in situ As content up to 15.4 wt.% in the deepest soil layer, and (iii) aluminosilicates, the least concentrated As carriers. The mineralogical evolution of As-bearing phases in the soil profile, coupled with the decrease of bulk As content, may be related to pedogenesis processes, suggesting an evolution of arsenates into As-rich Fe-oxyhydroxides. Therefore, weathering and mineralogical evolution of these As-rich phases may release As to surface waters.

A Bossy; C Grosbois; S Beauchemin; A Courtin-Nomade; W Hendershot; H Bril

2011-12-31T23:59:59.000Z

344

Geochemical and physical properties of soils and shallow sediments at the Savannah River Site  

Science Conference Proceedings (OSTI)

A program to characterize the geochemical and physical properties of the unimpacted soils and shallow sediments at the Savannah River Site (SRS) has been completed. The maximum, minimum, median, standard deviation, and mean values for metals, radionuclides, inorganic anions, organic compounds, and agricultural indicator parameters are summarized for six soil series that were identified as representative of the 29 soil series at SRS. The soils from unimpacted areas of SRS are typical of soils found in moderately aggressive weathering environments, including the southeastern United States. Appendix 8 organic compounds were detected in all samples. Since these constituents are not generally present in soil, this portion of the investigation was intended to assess possible laboratory artifacts. An additional objective of the SRS Soil Study was to determine if the composition of the split spoon sampler biased chemical analysis of the soils. Twenty-five duplicate samples were analyzed for a number of metals, radiological and agricultural parameters, and organics by two laboratories currently contracted with to analyze samples during waste site characterization. In all cases, the absolute values of the average differences are relatively small compared to the overall variability in the population. 31 refs., 14 figs., 48 tabs.

Looney, B.B.; Eddy, C.A.; Ramdeen, M.; Pickett, J. (Savannah River Lab., Aiken, SC (USA)); Rogers, V. (Soil Conservation Service, Aiken, SC (USA). Savannah River Site Savannah River Lab., Aiken, SC (USA)); Scott, M.T.; Shirley, P.A. (Sirrine Environmental Consultants, Greenville, SC (USA))

1990-08-31T23:59:59.000Z

345

Geochemical Fingerprinting of Coltan Ores by Machine Learning on Uneven Datasets  

Science Conference Proceedings (OSTI)

Two modern machine learning techniques, Linear Programming Boosting (LPBoost) and Support Vector Machines (SVMs), are introduced and applied to a geochemical dataset of niobium-tantalum ('coltan') ores from Central Africa to demonstrate how such information may be used to distinguish ore provenance, i.e., place of origin. The compositional data used include uni- and multivariate outliers and elemental distributions are not described by parametric frequency distribution functions. The 'soft margin' techniques of LPBoost and SVMs can be applied to such data. Optimization of their learning parameters results in an average accuracy of up to c. 92%, if spot measurements are assessed to estimate the provenance of ore samples originating from two geographically defined source areas. A parameterized performance measure, together with common methods for its optimization, was evaluated to account for the presence of uneven datasets. Optimization of the classification function threshold improves the performance, as class importance is shifted towards one of those classes. For this dataset, the average performance of the SVMs is significantly better compared to that of LPBoost.

Savu-Krohn, Christian, E-mail: christian.savu-krohn@unileoben.ac.at; Rantitsch, Gerd, E-mail: gerd.rantitsch@unileoben.ac.at [Montanuniversitaet Leoben, Department of Applied Geosciences and Geophysics (Austria); Auer, Peter, E-mail: auer@unileoben.ac.at [Chair for Information Technology, Montanuniversitaet Leoben (Austria); Melcher, Frank, E-mail: frank.melcher@bgr.de; Graupner, Torsten, E-mail: torsten.graupner@bgr.de [Federal Institute for Geosciences and Natural Resources (Germany)

2011-09-15T23:59:59.000Z

346

Changes in Bacterial And Archaeal Community Structure And Functional Diversity Along a Geochemically Variable Soil Profile  

SciTech Connect

Spatial heterogeneity in physical, chemical, and biological properties of soils allows for the proliferation of diverse microbial communities. Factors influencing the structuring of microbial communities, including availability of nutrients and water, pH, and soil texture, can vary considerably with soil depth and within soil aggregates. Here we investigated changes in the microbial and functional communities within soil aggregates obtained along a soil profile spanning the surface, vadose zone, and saturated soil environments. The composition and diversity of microbial communities and specific functional groups involved in key pathways in the geochemical cycling of nitrogen, Fe, and sulfur were characterized using a coupled approach involving cultivation-independent analysis of both 16S rRNA (bacterial and archaeal) and functional genes (amoA and dsrAB) as well as cultivation-based analysis of Fe(III)-reducing organisms. Here we found that the microbial communities and putative ammonia-oxidizing and Fe(III)-reducing communities varied greatly along the soil profile, likely reflecting differences in carbon availability, water content, and pH. In particular, the Crenarchaeota 16S rRNA sequences are largely unique to each horizon, sharing a distribution and diversity similar to those of the putative (amoA-based) ammonia-oxidizing archaeal community. Anaerobic microenvironments within soil aggregates also appear to allow for both anaerobic- and aerobic-based metabolisms, further highlighting the complexity and spatial heterogeneity impacting microbial community structure and metabolic potential within soils.

Hansel, C.M.; Fendorf, S.; Jardine, P.M.; Francis, C.A.

2009-05-18T23:59:59.000Z

347

Argonne Transportation Current News  

NLE Websites -- All DOE Office Websites (Extended Search)

materials (pdf) clean cities logo Clean Cities Transportation Workshop for Almaty, Kazakhstan Jeff Chamberlain Jeff Chamberlain discusses Argonne's breakthrough cathode...

348

NIST Transportation to NIST  

Science Conference Proceedings (OSTI)

Transportation to NIST. The National Institute of Standards and Technology is located approximately 25 miles north of Washington ...

2012-09-24T23:59:59.000Z

349

Transportation and its Infrastructure  

E-Print Network (OSTI)

Energy. OECD, 2004b: Current international shipping market trends -trends continue. In contrast, transport energy use in the mature market

2007-01-01T23:59:59.000Z

350

Transportation Security Update  

Science Conference Proceedings (OSTI)

The U.S. Department of Transportation (DOT) final rules issued in 2003 required persons who offer for transportation or transport certain hazardous materials to develop and implement security plans. The Electric Power Research Institute (EPRI) formed a Transportation Security Implementation Working Group, which included representation from the Nuclear Energy Institute (NEI), to identify key projects, which were documented in the original report in 2005. This report updates information in the original rep...

2011-07-27T23:59:59.000Z

351

Transportation Research and  

E-Print Network (OSTI)

Transportation Research and Analysis Computing Center Transportation Research and Analysis to supercomputers, we can simulate how individual bridges interact with sediment transport, local topography the bridge. Computer-based research at this highly detailed level promises to prevent future bridge disasters

Kemner, Ken

352

Nevada University Transportation  

E-Print Network (OSTI)

illnesses and disabilities · Development of professionals and future leaders in the area of transportationNUTC Nevada University Transportation Center University of Nevada, Las Vegas Sustainable Transporation in Arid Regions 2007-2009 Biennial Report 5 #12;2007-2009 Nevada University Transportation Center

Ahmad, Sajjad

353

PalladianDigest Transportation  

E-Print Network (OSTI)

PalladianDigest CONNECT. EMPOWER. GROW. Tackling Transportation Challenges Nebraska has been a vital link in the nation's transportation system since the days when carts, wagons to University of Nebraska­Lincoln research. That's fine with UNL transportation researchers, said Larry Rilett

Farritor, Shane

354

Northwestern University Transportation Center  

E-Print Network (OSTI)

Northwestern University Transportation Center 2011 Business Advisory Committee NUTC #12;#12;I have the pleasure of presenting our Business Advisory Committee members--a distinguished group of transportation industry lead- ers who have partnered with the Transportation Center in advancing the state of knowledge

Bustamante, Fabián E.

355

Introduction to Transportation Planning  

E-Print Network (OSTI)

Introduction to Transportation Planning CMP 4710/6710 Fall 2012 3 Credit Hours Room: ARCH 229 on a Saturday night, transportation is not an objective in and of itself, but a means to carry out the functions of daily living (i.e., it's a "derived good"). As a consequence, the transportation systems we build

Tipple, Brett

356

Louisiana Transportation Research Center  

E-Print Network (OSTI)

Louisiana Transportation Research Center LTRC www.ltrc.lsu.edu 2012-13 ANNUALREPORT #12;The Louisiana Transportation Research Center (LTRC) is a research, technology transfer, and training center administered jointly by the Louisiana Department of Transportation and Development (DOTD) and Louisiana State

Harms, Kyle E.

357

TRANSPORTATION: THE POTENTIAL  

E-Print Network (OSTI)

INTERMODAL TRANSPORTATION: THE POTENTIAL AND THE CHALLENGE A Summary Report 2003 #12;June 2003 To the Reader This report summarizes the second James L. Oberstar Forum on Transportation Policy and Technology. Over two days, we explored the chal- lenges and opportunities in intermodal transportation, addressing

Minnesota, University of

358

Transportation Demand Management Plan  

E-Print Network (OSTI)

Transportation Demand Management Plan FALL 2009 #12;T r a n s p o r t a t i o n D e m a n d M a n the transportation impacts the expanded enrollment will have. Purpose and Goal The primary goal of the TDM plan is to ensure that adequate measures are undertaken and maintained to minimize the transportation impacts

359

Neutron Radiography Reactor Reactivity -- Focused Lessons Learned  

SciTech Connect

As part of the Global Threat Reduction Initiative, the Neutron Radiography Reactor (NRAD) at the Idaho National Laboratory (INL) was converted from using highly enriched uranium (HEU) to low enriched uranium (LEU) fuel. After the conversion, NRAD resumed operations and is meeting operational requirements. Radiography image quality and the number of images that can be produced in a given time frame match pre-conversion capabilities. However, following the conversion, NRAD’s excess reactivity with the LEU fuel was less than it had been with the HEU fuel. Although some differences between model predictions and actual performance are to be expected, the lack of flexibility in NRAD’s safety documentation prevented adjusting the reactivity by adding more fuel, until the safety documentation could be modified. To aid future reactor conversions, a reactivity-focused Lessons Learned meeting was held. This report summarizes the findings of the lessons learned meeting and addresses specific questions posed by DOE regarding NRAD’s conversion and reactivity.

Eric Woolstenhulme; Randal Damiana; Kenneth Schreck; Ann Marie Phillips; Dana Hewit

2010-11-01T23:59:59.000Z

360

LES algorithm for turbulent reactive flows simulation  

Science Conference Proceedings (OSTI)

The paper presents the development and implementation of a Large Eddy Simulation numerical algorithm for simulating turbulent reactive flows. The numerical algorithm is based on a 5 step modified Runge - Kutta numerical scheme with a dual time stepping ... Keywords: Runge - Kutta numerical scheme, large eddy simulation, linear eddy model

Ionut Porumbel; Cristian Cârl?nescu; Florin Gabriel Florean; Constantin Eusebiu Hritcu

2010-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Transportation Business Plan  

SciTech Connect

The Transportation Business Plan is a step in the process of procuring the transportation system. It sets the context for business strategy decisions by providing pertinent background information, describing the legislation and policies governing transportation under the NWPA, and describing requirements of the transportation system. Included in the document are strategies for procuring shipping casks and transportation support services. In the spirit of the NWPA directive to utilize the private sector to the maximum extent possible, opportunities for business ventures are obvious throughout the system development cycle.

1986-01-01T23:59:59.000Z

362

Public Works Transportation Infrastructure Study  

E-Print Network (OSTI)

Public Works Transportation Infrastructure Study Minneapolis City of Lakes Minneapolis Public Works Transportation Infrastructure Study #12;Public Works Transportation Infrastructure Study Minneapolis City Works Transportation Infrastructure Study Minneapolis City of Lakes Background: · Currently, funding

Minnesota, University of

363

Center for Intermodal Transportation Safety  

E-Print Network (OSTI)

Center for Intermodal Transportation Safety and Security Panagiotis Scarlatos, Ph.D., Director Transportation Safety and Security #12;Center for Intermodal Transportation Safety and Security Partners #12 evacuations · Tracking systems for hazardous materials Center for Intermodal Transportation Safety

Fernandez, Eduardo

364

Transportation Planning & Decision Science Group Transportation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Viewer Unveiled at ITS-America Meeting in Nashville At the Annual Intelligent Transportation Association of America (ITS-A) meeting held in Nashville on April 22 - 24, the...

365

National Transportation Stakeholders Forum  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Transportation Stakeholders Forum Transportation Stakeholders Forum May 14-16, 2013 Tuesday, May 14 7:00 am - 5:00 pm Registration Niagara Foyer 7:00 am - 7:45 am Breakfast and Networking Grand A 8:00 am - 10:00 am National Updates for Transportation Stakeholder Groups and Guests - Panel Grand BC Moderator: John Giarrusso Jr., MA Emergency Management Agency / Northeast High-Level Radioactive Waste Transportation Task Force Co-Chair US Department of Energy, Office of Environmental Management - Steve O'Connor, Director, Office of Packaging & Transportation US Nuclear Regulatory Commission - Earl P. Easton, Senior Level Advisor (retired) and David W. Pstrak, Transportation and Storage Specialist, Division of Spent Fuel Storage and Transportation

366

Transportation System Requirements Document  

SciTech Connect

This Transportation System Requirements Document (Trans-SRD) describes the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of this document is to define the system-level requirements for Transportation consistent with the CRWMS Requirement Document (CRD). These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presents an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. The interface identification and description are published in the CRWMS Interface Specification.

1993-09-01T23:59:59.000Z

367

Method for generating a highly reactive plasma for exhaust gas after treatment and enhanced catalyst reactivity  

DOE Patents (OSTI)

This patent application describes a method and apparatus of exhaust gas remediation that enhance the reactivity of the material catalysts found within catalytic converters of cars, trucks, and power stations.

Whealton, John H.; Hanson, Gregory R.; Storey, John M.; Raridon, Richard J.; Armfield, Jeffrey S.; Bigelow, Timothy S.; Graves, Ronald L.

2000-07-01T23:59:59.000Z

368

Vadose Zone Transport Field Study: Summary Report  

SciTech Connect

From FY 2000 through FY 2003, a series of vadose zone transport field experiments were conducted as part of the U.S. Department of Energy’s Groundwater/Vadose Zone Integration Project Science and Technology Project, now known as the Remediation and Closure Science Project, and managed by the Pacific Northwest National Laboratory (PNNL). The series of experiments included two major field campaigns, one at a 299-E24-11 injection test site near PUREX and a second at a clastic dike site off Army Loop Road. The goals of these experiments were to improve our understanding of vadose zone transport processes; to develop data sets to validate and calibrate vadose zone flow and transport models; and to identify advanced monitoring techniques useful for evaluating flow-and-transport mechanisms and delineating contaminant plumes in the vadose zone at the Hanford Site. This report summarizes the key findings from the field studies and demonstrates how data collected from these studies are being used to improve conceptual models and develop numerical models of flow and transport in Hanford’s vadose zone. Results of these tests have led to a better understanding of the vadose zone. Fine-scale geologic heterogeneities, including grain fabric and lamination, were observed to have a strong effect on the large-scale behavior of contaminant plumes, primarily through increased lateral spreading resulting from anisotropy. Conceptual models have been updated to include lateral spreading and numerical models of unsaturated flow and transport have revised accordingly. A new robust model based on the concept of a connectivity tensor was developed to describe saturation-dependent anisotropy in strongly heterogeneous soils and has been incorporated into PNNL’s Subsurface Transport Over Multiple Phases (STOMP) simulator. Application to field-scale transport problems have led to a better understanding plume behavior at a number of sites where lateral spreading may have dominated waste migration (e.g. BC Cribs and Trenches). The improved models have been also coupled with inverse models and newly-developed parameter scaling techniques to allow estimation of field-scale and effective transport parameters for the vadose zone. The development and utility of pedotransfer functions for describing fine-scale hydrogeochemical heterogeneity and for incorporating this heterogeneity into reactive transport models was explored. An approach based on grain-size statistics appears feasible and has been used to describe heterogeneity in hydraulic properties and sorption properties, such as the cation exchange capacity and the specific surface area of Hanford sediments. This work has also led to the development of inverse modeling capabilities for time-dependent, subsurface, reactive transport with transient flow fields using an automated optimization algorithm. In addition, a number of geophysical techniques investigated for their potential to provide detailed information on the subtle changes in lithology and bedding surfaces; plume delineation, leak detection. High-resolution resistivity is now being used for detecting saline plumes at several waste sites at Hanford, including tank farms. Results from the field studies and associated analysis have appeared in more than 46 publications generated over the past 4 years. These publications include test plans and status reports, in addition to numerous technical notes and peer reviewed papers.

Ward, Andy L.; Conrad, Mark E.; Daily, William D.; Fink, James B.; Freedman, Vicky L.; Gee, Glendon W.; Hoversten, Gary M.; Keller, Jason M.; Majer, Ernest L.; Murray, Christopher J.; White, Mark D.; Yabusaki, Steven B.; Zhang, Z. F.

2006-07-31T23:59:59.000Z

369

Behavior of Laminate Reactive Materials under Dynamic Loading ...  

Science Conference Proceedings (OSTI)

Presentation Title, Behavior of Laminate Reactive Materials under Dynamic Loading ... Atomistically-Informed Dislocation Dynamics Simulations of High Rate  ...

370

SIC Manufature via Reactive Infiltration - Programmaster.org  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Ceramic Matrix Composites. Presentation Title, SIC Manufature via Reactive ...

371

Multiple Steady States in Azeotropic and Reactive Distillation  

E-Print Network (OSTI)

Introduction . Motivation Overview on the Contributions MSS in Reactive Distillation Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions . The Starting Point . Consolidation . Industrial Applications . Incorporating Reactions MSS in Reactive Distillation Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions MSS in Reactive Distillation . Prediction Method . MTBE Process Conclusions Outline Multiple Steady States (MSS) Overview on the Contributions MSS in Reactive Distillation Conclusions Distillation Overview . Ideal binary / multicomponent distillation . Homogeneous azeotropic distillation -- Heavy entrainer (extractive distillation) -- Intermediate entrainer -- "Boundary scheme" (ligh

Thomas E. Güttinger

1998-01-01T23:59:59.000Z

372

The implementation of a 3D characteristics solver for the generation of incremental cross sections for reactivity devices in a CANDU reactor  

SciTech Connect

We are presenting issues related to the generation of consistent incremental cross sections for the reactivity devices in a CANDU reactor. Such calculations involve the solution of the neutron transport equation over complex 3D geometries representing a single vertical reactivity device inserted mid-way between two horizontal fuel channels. The DRAGON lattice code has recently been upgraded and can handle the exact geometry of such configurations for trajectory-based transport solvers. Within this framework, the detailed representation of the reactivity devices implies an increase in the number of regions when the strongly absorbing regions and fuel clusters are described without cylinderization. In this paper, a solution based on the characteristics method is compared with the standard procedure, based on the collision probabilities method. The coherence of both solvers is highlighted and a comparison of their computational costs is presented. (authors)

Le Tellier, R.; Hebert, A.; Marleau, G. [Ecole Polytechnique de Montreal, C.P. 6079 suce. Centre-Ville, Montreal, Que. H3C 3A7 (Canada)

2006-07-01T23:59:59.000Z

373

Nuclear reactivity control using laser induced polarization  

DOE Patents (OSTI)

A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

Bowman, Charles D. (Los Alamos, NM)

1991-01-01T23:59:59.000Z

374

Nuclear reactivity control using laser induced polarization  

DOE Patents (OSTI)

A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neturons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

Bowman, Charles D. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

375

Reactivity control assembly for nuclear reactor. [LMFBR  

DOE Patents (OSTI)

This invention, which resulted from a contact with the United States Department of Energy, relates to a control mechanism for a nuclear reactor and, more particularly, to an assembly for selectively shifting different numbers of reactivity modifying rods into and out of the core of a nuclear reactor. It has been proposed heretofore to control the reactivity of a breeder reactor by varying the depth of insertion of control rods (e.g., rods containing a fertile material such as ThO/sub 2/) in the core of the reactor, thereby varying the amount of neutron-thermalizing coolant and the amount of neutron-capturing material in the core. This invention relates to a mechanism which can advantageously be used in this type of reactor control system.

Bollinger, L.R.

1982-03-17T23:59:59.000Z

376

Treatment of Radioactive Reactive Mixed Waste  

Science Conference Proceedings (OSTI)

PacificEcoSolutions, Inc. (PEcoS) has installed a plasma gasification system that was recently modified and used to destroy a trimethyl-aluminum mixed waste stream from Los Alamos National Laboratory (LANL.) The unique challenge in handling reactive wastes like trimethyl-aluminum is their propensity to flame instantly on contact with air and to react violently with water. To safely address this issue, PacificEcoSolutions has developed a new feed system to ensure the safe containment of these radioactive reactive wastes during transfer to the gasification unit. The plasma gasification system safely processed the radioactively contaminated trimethyl-metal compounds into metal oxides. The waste stream came from LANL research operations, and had been in storage for seven years, pending treatment options. (authors)

Colby, S.; Turner, Z.; Utley, D. [Pacific EcoSolutions, Inc., 2025 Battelle Boulevard, Richland, Washington 99354 (United States); Duy, C. [Los Alamos National Laboratory - LA-UR-05-8410, Post Office Box 1663 MS J595, Los Alamos, New Mexico 97545 (United States)

2006-07-01T23:59:59.000Z

377

Nuclear reactivity control using laser induced polarization  

DOE Patents (OSTI)

A control element for reactivity control of a fission source provides an atomic density of {sup 3}He in a control volume which is effective to control criticality as the {sup 3}He is spin-polarized. Spin-polarization of the {sup 3}He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the {sup 3}He for spin-polarizing the {sup 3}He. An alkali-metal vapor may be included with the {sup 3}He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with {sup 3}He to spin-polarize the {sup 3}He atoms. 5 figs.

Bowman, C.D.

1989-05-26T23:59:59.000Z

378

Real time reactive programming in lucid enriched with contexts  

Science Conference Proceedings (OSTI)

We present a synchronous approach to real-time reactive programming in Lucid enriched with contexts as first class objects. The declarative intensional approach allows real-time reactive programs to manipulate both events and state-based representations ... Keywords: contexts, formal verification, intensional programming, real-time reactive programming

Kaiyu Wan; Vasu Alagar; Joey Paquet

2004-09-01T23:59:59.000Z

379

Modeling brine-rock interactions in an enhanced geothermal system deep fractured reservoir at Soultz-Sous-Forets (France): a joint approach using two geochemical codes: frachem and toughreact  

E-Print Network (OSTI)

150 p. Bächler, D. , Durst, P. , Evans, K. , Hopkirk, R. ,in Mineralogy, 29: 259-308. Durst, P. , (2002). Geochemical1999. Rabemanana, V. , Durst, P. , Bächler, D. , Vuataz,

Andre, Laurent; Spycher, Nicolas; Xu, Tianfu; Vuataz, Francois-D.; Pruess, Karsten.

2006-01-01T23:59:59.000Z

380

Reactive gas atomization processing for Fe-based ODS alloys  

SciTech Connect

Gas atomization reaction synthesis was employed as a simplified method for processing oxide dispersion forming precursor Fe-based powders (e.g., Fe–Cr–Y–Hf). During this process a reactive atomization gas (i.e., Ar–O2) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 50 nm) metastable Cr-enriched oxide shell that was used as a vehicle to transport oxygen into the consolidated microstructure. Subsequent elevated temperature heat treatment promoted thermodynamically driven oxygen exchange reactions between trapped films of Cr-enriched oxide and internal (Y, Hf)-enriched intermetallic precipitates, resulting in highly stable nano-metric mixed oxide dispersoids (i.e., Y–Hf–O) that were identified with X-ray diffraction. Transmission electron microscopy and atom probe tomography results also revealed that the size and distribution of the dispersoids were found to depend strongly on the original rapidly solidified microstructure. To exploit this, several oxide dispersion strengthened microstructures were engineered from different powder particle size ranges, illustrating microstructural control as a function of particle solidification rate. Additionally, preliminary thermal–mechanical processing was used to develop a fine scale dislocation substructure for ultimate strengthening of the alloy.

Rieken, Joel R [Ames Laboratory; Anderson, Iver E [Ames Laboratory; Kramer, Matthew J [Ames Laboratory; Odette, G R [University of California; Stergar, E [University of California; Haney, E [University of California

2011-08-24T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Predictive modeling of reactive wetting and metal joining.  

SciTech Connect

The performance, reproducibility and reliability of metal joints are complex functions of the detailed history of physical processes involved in their creation. Prediction and control of these processes constitutes an intrinsically challenging multi-physics problem involving heating and melting a metal alloy and reactive wetting. Understanding this process requires coupling strong molecularscale chemistry at the interface with microscopic (diffusion) and macroscopic mass transport (flow) inside the liquid followed by subsequent cooling and solidification of the new metal mixture. The final joint displays compositional heterogeneity and its resulting microstructure largely determines the success or failure of the entire component. At present there exists no computational tool at Sandia that can predict the formation and success of a braze joint, as current capabilities lack the ability to capture surface/interface reactions and their effect on interface properties. This situation precludes us from implementing a proactive strategy to deal with joining problems. Here, we describe what is needed to arrive at a predictive modeling and simulation capability for multicomponent metals with complicated phase diagrams for melting and solidification, incorporating dissolutive and composition-dependent wetting.

van Swol, Frank B.

2013-09-01T23:59:59.000Z

382

Transportation | Argonne National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Transportation From modeling and simulation programs to advanced electric powertrains, engines, biofuels, lubricants, and batteries, Argonne's transportation research is vital to the development of next-generation vehicles. Revolutionary advances in transportation are critical to reducing our nation's petroleum consumption and the environmental impact of our vehicles. Some of the most exciting new vehicle technologies are being ushered along by research conducted at Argonne National Laboratory. Our Transportation Technology R&D Center (TTRDC) brings together scientists and engineers from many disciplines across the laboratory to work with the U.S. Department of Energy (DOE), automakers and other industrial partners. Our goal is to put new transportation technologies on the road that improve

383

Transportation Services | Staff Services  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Services Transportation Services The BNL Transportation Office, located at 20 Brookhaven Avenue, Building 400A, is available to assist BNL employees, guests and visitors with transportation needs in support of Laboratory programs. The hours of operation are 8:30 AM - 5:00 PM Monday through Friday. To contact the Transportation Office call (631) 344-2535. Stony Brook Parking Passes The Transportation Office has a limited number of parking passes for the three (3) parking garages at Stony Brook University. The passes are available to and are intended for use by BNL employees/scientific staff on official business only. Passes may be used at the Administration, University Hospital and Health Services Center garages on the Stony Brook campus when visiting SBU on official business.

384

Transportation technology at Sandia  

SciTech Connect

Industrial and military activities in the US produce large amounts of hazardous mixed waste, which includes both radioactive and toxic substances. The already overburdened environment is faced with the task of safely disposing of these complex wastes. A very important aspect of this effort is the safe and economical transportation of radioactive and toxic chemical wastes to projected repositories. Movement of wastes to the repository sites is accomplished by a combination of truck, rail, ship, and air. The DOE directs transportation activities including cask development technology for use in single or multimode transport. Sandia National Laboratories` Transportation Technology programs provide the technology and know-how to support DOE in achieving safe, efficient, and economical packaging and transportation of nuclear and other hazardous waste materials. This brochure describes the Transportation Technology programs and the specialized techniques and capabilities they offer to prospective users.

1994-12-31T23:59:59.000Z

385

Hydrologic and geochemical controls on soluble benzene migration in sedimentary basins  

E-Print Network (OSTI)

springs and exploration wells can be useful only when the oil reservoir is located within about 20 km sampled from exploration wells are thus used as indicators of undiscovered oil fields (Hunt 1979; Jones as the primary transport mechanism (Fig. 1). Moreover, BTEX soil gas anomalies in the vicinity of oil fields have

Zhang, Ye

386

Update Sustainable Transportation  

NLE Websites -- All DOE Office Websites (Extended Search)

on the significant impacts and breadth of transportation science research at ORNL and new directions to achieve efficient, clean, and sustainable mobility. Ron's talk attracted...

387

Transportation Storage Interface  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

and Transportation: Technical Needs 13 * High priority degradation areas: * Stress corrosion cracking of stainless steel canister body and welds * Degradation of cask bolts *...

388

Rail Coal Transportation Rates  

U.S. Energy Information Administration (EIA)

figure data Figure 7 shows the percent change in average real rates for those state-to-state ... Estimated transportation rates for coal delivered to electric ...

389

Sustainable Transportation (Fact Sheet)  

DOE Green Energy (OSTI)

This document highlights DOE's Office of Energy Efficiency and Renewable Energy's advancements in transportation technologies, alternative fuels, and fuel cell technologies.

Not Available

2012-09-01T23:59:59.000Z

390

Defects and Transport I  

Science Conference Proceedings (OSTI)

Oct 8, 2012 ... Secondary Transport Phenomena in Ceramic Membranes under ... the specific case of mixed proton/oxygen vacancy/electronic conduction in a ...

391

Transport in PEMFC Stacks  

NLE Websites -- All DOE Office Websites (Extended Search)

any proprietary, confidential, or otherwise restricted information September 30 th 2009 Washington, DC 1 Transport in PEMFC Stacks Cortney Mittelsteadt Bryn McPheeters This...

392

Sustainability and Transport  

E-Print Network (OSTI)

pdf/Hughes_D_NatGas_Boston_2006. pdf> Idaho.2005. Idaho Bicycle and Pedestrian Program.Boise, Idaho: Idaho Transportation Department [cited 13

Gilbert, Richard

2006-01-01T23:59:59.000Z

393

Boulder Area Transportation  

Science Conference Proceedings (OSTI)

... NIST does not endorse or guarantee the quality or services provided by these businesses. All Denver/Boulder area transportation companies. ...

2011-11-16T23:59:59.000Z

394

Argonne Transportation Current News  

NLE Websites -- All DOE Office Websites (Extended Search)

one-stop shop for news, photographs and other interesting reference information on transportation research. Current News Read current news and research highlights. Archives: 2011...

395

Argonne Transportation - Podolski Award  

NLE Websites -- All DOE Office Websites (Extended Search)

Scientists Receives Award for Contributions in Intelligent Transportation Systems Tentner Receives ITS Miwest Award Adrian Tentner receives the first Chapter Service Award from ITS...

396

Aluminum in Transportation  

Science Conference Proceedings (OSTI)

Presentation Title, Aluminum in Transportation: Case Study of the Development of a ... The unit was entirely redesigned using aluminum and based on the future

397

Transportation and its Infrastructure  

E-Print Network (OSTI)

be competitive, but the quantity of waste oils is minisculeoils are currently being used as biodiesel transport fuel in limited quantities and

2007-01-01T23:59:59.000Z

398

Transportation | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

SHARE Transportation Research ORNL researcher Jim Szybist uses a variable valve-train engine to evaluate different types of fuels, including ethanol blends, and their...

399

Transportation Energy Futures  

E-Print Network (OSTI)

TRANSPORTATION ment of Oil Shale Technology. Washing- ton,interest and investments in oil shale, ethanol, coal liquidsbiomass materials, coal, oil shale, tar sands, natural gas,

Sperling, Daniel

1989-01-01T23:59:59.000Z

400

Transportation and its Infrastructure  

E-Print Network (OSTI)

Options for Liquid Biofuels Development in Ireland. SEI, 562006: Outlook for advanced biofuels. Energy Policy, 34(17),40 pp. IEA, 2004c: Biofuels for Transport: An International

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Geological, geochemical, and operational summary, aurora well, OCS Y-0943-1, Beaufort Sea, Alaska. Final report  

Science Conference Proceedings (OSTI)

The Aurora well is located just off the coast of the Arctic National Wildlife Refuge (ANWR). The well was spudded November 2, 1987, in 68 ft of water and plugged and abandoned 286 days later on August 30, 1988, after drilling to a total depth (TD) of 18,325 ft below the Kelly Bushing (RKB). The report presents our interpretations of the geologic and geochemical information collected from the Aurora well. Additionally, a significant section of the report is devoted to the operational aspects of drilling the Aurora well.

Paul, L.E.; Choromanski, D.R.; Turner, R.F.; Flett, T.O.; Paul, L.E.

1994-01-01T23:59:59.000Z

402

2006 TRANSPORTATION TOMORROW SURVEY JOINT PROGRAM IN TRANSPORTATION  

E-Print Network (OSTI)

2006 TRANSPORTATION TOMORROW SURVEY JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO 2006 Transportation Tomorrow Survey Data Presentation #12;2006 TRANSPORTATION TOMORROW SURVEY JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO City of Hamilton City of Kawartha Lakes City of Guelph City of Brantford

Toronto, University of

403

Conservation in transportation  

Science Conference Proceedings (OSTI)

A nationwide examination was made of grassroots energy conservation programs related to transportation. Information compiled from civic groups, trade associations, and corporations is included on driver awareness/mass transit; travel; and ride sharing. It is concluded that a willingness by the public to cooperate in transportation energy conservation exists and should be exploited. (LCL)

None

1980-05-30T23:59:59.000Z

404

Biofuels and Transportation  

E-Print Network (OSTI)

Biofuels and Transportation Impacts and Uncertainties Some Observations of a Reformed Ethanol and Logistics Symposium 3 Topics · Why Biofuels · Ethanol Economics · Ethanol Transportation Equipment Biofuels? · National Security · Reduce Imports of oil · Peak Oil · Replace Fossil Resources

Minnesota, University of

405

Transport in porous and fractured media of the Creede Formation  

DOE Green Energy (OSTI)

Direct measurement was made of the hydraulic conductivity of Creede Formation rocks using a new experimental method. The UFA{trademark} method employs open-flow centrifugation. Centrifugation, like gravity, has the effect on a material of a whole-body force exerting equal force at all points within the sample. The equivalent gravitational force exerted throughout the sample can be chosen to be from one to four orders of magnitude higher than earth gravity (from 10 to 10,000 g). The result is an increase in rate of fluid flow equally at all points throughout the sample so that hydraulic steady state is obtained in most geologic materials in hours, even under highly unsaturated conditions. This extraordinarily short time allows direct measurement of transport parameters, such as hydraulic conductivity, diffusion coefficient, and retardation factors, in any porous media over the complete range of field moisture contents. Hydraulic conductivities in the Creede Formation rocks ranged from 10{sup {minus}12} cm/s to 10{sup {minus}7} cm/s (10{sup {minus}9} Darcy to 10{sup {minus}4} Darcy) and showed no correlation with any other physical or mineralogical properties including porosity. The high degree of alteration to clay minerals appears to obscure any porosity/permeability relationship of the kind that occurs in many reservoir rocks. However, down-hole neutron porosities correlated well with laboratory-determined porosities. The objective of this investigation is to determine the hydrologic transport parameters of Creede Formation rocks for use in transport model development and for image analysis of transport pathways to produce a porosity/permeability evolution curve in support of geochemical and isotopic water/rock interaction models.

Conca, J.L.

1995-12-31T23:59:59.000Z

406

Numerical Modeling of 90Sr and 137Cs Transport from a Spill in the B-Cell of the 324 Building, Hanford Site 300 Area  

SciTech Connect

To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.

Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J.; Clayton, Ray E.

2012-03-19T23:59:59.000Z

407

Transportation | Open Energy Information  

Open Energy Info (EERE)

Transportation Transportation Jump to: navigation, search Click to return to AEO2011 page AEO2011 Data From AEO2011 report . Market Trends From 2009 to 2035, transportation sector energy consumption grows at an average annual rate of 0.6 percent (from 27.2 quadrillion Btu to 31.8 quadrillion Btu), slower than the 1.2 percent average rate from 1975 to 2009. The slower growth is a result of changing demographics, increased LDV fuel economy, and saturation of personal travel demand.[1] References [1] ↑ 1.0 1.1 AEO2011 Transportation Sector Retrieved from "http://en.openei.org/w/index.php?title=Transportation&oldid=378906" What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load)

408

Argonne Transportation Current News  

NLE Websites -- All DOE Office Websites (Extended Search)

8 Transportation News & Highlights 8 Transportation News & Highlights EDTA Publications Now Online December 2008 -- View them here. Argonne to advise battery alliance December 2008 -- A coalition of more than fourteen companies has announced the creation of a new business alliance aimed at promoting U.S. production of lithium ion batteries. The newly formed National Alliance for Advanced Transportation Battery Cell Manufacture is based in Chicago. Argonne National Laboratory will serve in an advisory role as the Alliance begins operations. More... French Auto Industry Visits Center for Transportation Research November 18, 2008 -- Representatives of the French auto industry visited the Argonne Center for Transportation Research on November 18, 2008. The purpose of the visit was to share information and discuss technology opportunities for hybrid and electric vehicles. More...

409

Undulator Transportation Test Results  

SciTech Connect

A test was performed to determine whether transporting and handling the undulators makes any changes to their properties. This note documents the test. No significant changes to the test undulator were observed. After the LCLS undulators are tuned and fiducialized in the Magnetic Measurement Facility (MMF), they must be transported to storage buildings and transported to the tunnel. It has been established that the undulators are sensitive to temperature. We wish to know whether the undulators are also sensitive to the vibrations and shocks of transportation. To study this issue, we performed a test in which an undulator was measured in the MMF, transported to the tunnel, brought back to the MMF, and re-measured. This note documents the test and the results.

Wolf, Zachary

2010-11-17T23:59:59.000Z

410

INLAND PORT TRANSPORTATION EVALUATION GUIDE  

E-Print Network (OSTI)

INLAND PORT TRANSPORTATION EVALUATION GUIDE by Robert Harrison, Center for Transportation Research Transportation Institute, The Texas A&M University System; and Jolanda Prozzi, Center for Transportation Research, The University of Texas at Austin CENTER FOR TRANSPORTATION RESEARCH Bureau of Engineering Research

Texas at Austin, University of

411

http://tti.tamu.edu Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight  

E-Print Network (OSTI)

http://tti.tamu.edu Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight pipeline transportation >>> Transportation operat > Freight traffic > Commodities > Travel time > Travel demand > http

412

Preparation of reactive beta-dicalcium silicate  

DOE Patents (OSTI)

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane and hydrogen, at a temperature of about 850.degree.-1000.degree. C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

Shen, Ming-Shing (Laramie, WY, NJ); Chen, James M. (Rahway, NJ); Yang, Ralph T. (Amherst, NY)

1982-01-01T23:59:59.000Z

413

Preparation of reactive beta-dicalcium silicate  

DOE Patents (OSTI)

This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica, and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane, and hydrogen, at a temperature of about 850 to 1000/sup 0/C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

Shen, M.S.; Chen, J.M.; Yang, R.T.

1980-02-28T23:59:59.000Z

414

Reactive sticking coefficients of silane on silicon  

SciTech Connect

Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition rate measurements using molecular beam scattering and a very low pressure cold wall reactor. The RSCs have non-Arrhenius temperature dependences and decreases with increasing flux at low (710/sup 0/) temperatures. A simple model involving dissociative adsorption of silane is consistent with these results. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction.

Buss, R.J.; Ho, P.; Breiland, W.G.; Coltrin, M.E.

1988-09-15T23:59:59.000Z

415

Geologic, geochemical, and geographic controls on NORM in produced water from Texas oil, gas, and geothermal reservoirs. Final report  

DOE Green Energy (OSTI)

Water from Texas oil, gas, and geothermal wells contains natural radioactivity that ranges from several hundred to several thousand Picocuries per liter (pCi/L). This natural radioactivity in produced fluids and the scale that forms in producing and processing equipment can lead to increased concerns for worker safety and additional costs for handling and disposing of water and scale. Naturally occurring radioactive materials (NORM) in oil and gas operations are mainly caused by concentrations of radium-226 ({sup 226}Ra) and radium-228 ({sup 228}Ra), daughter products of uranium-238 ({sup 238}U) and thorium-232 ({sup 232}Th), respectively, in barite scale. We examined (1) the geographic distribution of high NORM levels in oil-producing and gas-processing equipment, (2) geologic controls on uranium (U), thorium (Th), and radium (Ra) in sedimentary basins and reservoirs, (3) mineralogy of NORM scale, (4) chemical variability and potential to form barite scale in Texas formation waters, (5) Ra activity in Texas formation waters, and (6) geochemical controls on Ra isotopes in formation water and barite scale to explore natural controls on radioactivity. Our approach combined extensive compilations of published data, collection and analyses of new water samples and scale material, and geochemical modeling of scale Precipitation and Ra incorporation in barite.

Fisher, R.

1995-08-01T23:59:59.000Z

416

Development and Application of a Paleomagnetic/Geochemical Method for Constraining the Timing of Burial Diagenetic and Fluid  

SciTech Connect

Studies of diagenesis caused by fluid migration or other events are commonly hindered by a lack of temporal control. Our results to date demonstrate that a paleomagnetic/geochemical approach can be used to date fluid migration as well as burial diagenetic events. Our principal working hypothesis is that burial diagenetic processes (e.g., maturation of organic-rich sediments and clay diagenesis) and the migration of fluids can trigger the authigenesis of magnetic mineral phases. The ages of these events can be constrained by comparing chemical remanent magnetizations (CRMs) to independently established Apparent Polar Wander Paths. While geochemical (e.g. stable isotope and organic analyses) and petrographic studies provide important clues for establishing these relationships, the ultimate test of this hypothesis requires the application of independent dating methods to verify the paleomagnetic ages. Towards this end, we have used K-Ar dating of illitization as an alternative method for constraining the ages of magnetic mineral phases in our field areas.

Elmore, Richard D.; Engel, Michael H.

2005-03-10T23:59:59.000Z

417

Multielement geochemical exploration data for the Cove Fort-Sulphurdale Known Geothermal Resource Area, Beaver and Millard counties, Utah  

DOE Green Energy (OSTI)

Multielement geochemical exploration data have been acquired for the Cove Fort-Sulphurdale Known Geothermal Resource Area (KGRA). This was accomplished by analysis of both whole rock and +3.3 specific gravity concentrate samples from cuttings composites collected from shallow rotary drill holes. Areal distributions are reported for arsenic, mercury, lead and zinc. These are elements indicated by previous studies to be broadly zoned around thermal centers in geothermal systems and thus to be useful for selecting and prioritizing drilling targets. Results from this work suggest that reservoir temperature and/or reservoir to surface permeability, and thus possibly overall potential for a geothermal resource, increase northward beneath the approximately 18 square mile area containing shallow drill holes, possibly to beyond the northern limits of the area. The data provide a basis for development of three principal target models for the geothermal system but do not permit prioritization of these models. It is recommended that geochemical, geological, and temperature gradient surveys be expanded northward from the present survey area to more fully define the area which appears to have the best resource potential and to aid prioritization of the target models.

Bamford, R.W.; Christensen, O.D.

1979-09-01T23:59:59.000Z

418

Microbial community structure of hydrothermal deposits from geochemically different vent fields along the Mid-Atlantic Ridge  

Science Conference Proceedings (OSTI)

To evaluate the effects of local fluid geochemistry on microbial communities associated with active hydrothermal vent deposits, we examined the archaeal and bacterial communities of 12 samples collected from two very different vent fields: the basalt-hosted Lucky Strike (37 17'N, 32 16.3'W, depth 1600-1750 m) and the ultramafic-hosted Rainbow (36 13'N, 33 54.1'W, depth 2270-2330 m) vent fields along the Mid-Atlantic Ridge (MAR). Using multiplexed barcoded pyrosequencing of the variable region 4 (V4) of the 16S rRNA genes, we show statistically significant differences between the archaeal and bacterial communities associated with the different vent fields. Quantitative polymerase chain reaction (qPCR) assays of the functional gene diagnostic for methanogenesis (mcrA), as well as geochemical modelling to predict pore fluid chemistries within the deposits, support the pyrosequencing observations. Collectively, these results show that the less reduced, hydrogen-poor fluids at Lucky Strike limit colonization by strict anaerobes such as methanogens, and allow for hyperthermophilic microaerophiles, like Aeropyrum. In contrast, the hydrogen-rich reducing vent fluids at the ultramafic-influenced Rainbow vent field support the prevalence of methanogens and other hydrogen-oxidizing thermophiles at this site. These results demonstrate that biogeographical patterns of hydrothermal vent microorganisms are shaped in part by large scale geological and geochemical processes.

Flores, Gilberto E [Portland State University; Campbell, James H [ORNL; Kirshtein, Julie D [United States Geological Survey, Reston, VA; Meneghin, Jennifer [Portland State University; Podar, Mircea [ORNL; Steinberg, Joshua [Oregon Episcopal School, Portland, OR; Seewald, Jeffrey S [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Tivey, Margaret Kingston [Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA; Voytek, Mary A [United States Geological Survey & National Aeronautics and Space Administration; Reysenbach, Anna-Louise [Portland State University; Yang, Zamin Koo [ORNL

2011-01-01T23:59:59.000Z

419

Amyloid precursor protein and axonal transport  

E-Print Network (OSTI)

relationship to axonal transport . 1 Chapter II – Mutationsits axonal transport ……………………………. ………………………. ……………… 10undergoes axonal transport ……………………. 42 Figure 2.4. Effect

Rodrigues, Elizabeth M.

2010-01-01T23:59:59.000Z

420

Transportation Storage Interface | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Storage Interface Transportation Storage Interface Regulation of Future Extended Storage and Transportation. Transportation Storage Interface More Documents & Publications Status...

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Spring 2013 National Transportation Stakeholders Forum Meeting...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

National Transportation Stakeholders Forum Spring 2013 National Transportation Stakeholders Forum Meeting, New York Spring 2013 National Transportation Stakeholders Forum...

422

Materials Transportation Testing & Analysis at Sandia National...  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Testing & Analysis Mission Sandia's Transportation Risk & Packaging Program develops innovative technologies and methodologies to solve transportation and packaging...

423

Automated Transportation Management System (ATMS) | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Waste Management Packaging and Transportation Automated Transportation Management System (ATMS) Automated Transportation Management System (ATMS) The Department of Energy's...

424

Transuranic Waste Transportation Working Group Agenda | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Transportation Working Group Agenda Transuranic Waste Transportation Working Group Agenda Transuranic Waste Transportation Working Group Agenda More Documents & Publications...

425

Transportation Emergency Preparedness Program (TEPP) | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Packaging and Transportation Transportation Emergency Preparedness Program (TEPP) Transportation Emergency Preparedness Program (TEPP) In an effort to address responder...

426

One-dimensional solute transport in a permeable reactive barrieraquifer system  

E-Print Network (OSTI)

[Gupta and Fox, 1999; Hemsi and Shackelford, 2006], or design considerations, such as the spatial [Gupta and Fox, 1999; Hemsi and Shackelford, 2006]. Since the early stage of PRB optimi- zation studies

Zhan, Hongbin

427

Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada  

E-Print Network (OSTI)

Unsaturated Zone at Yucca Mountain, Nevada. U.S. Geologicalzone model at Yucca Mountain, Nevada. J. Contaminantinvesti- gations at Yucca Mountain - the potential

Spycher, N.F.; Sonnenthal, E.L.; Apps, J.A.

2002-01-01T23:59:59.000Z

428

Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada  

E-Print Network (OSTI)

and refluxing of steam condensate towards the boiling front.and refluxing of steam condensate towards the boiling front.

Spycher, N.F.; Sonnenthal, E.L.; Apps, J.A.

2002-01-01T23:59:59.000Z

429

Modeling reactive transport in deformable porous media using the theory of interacting continua.  

SciTech Connect

This report gives an overview of the work done as part of an Early Career LDRD aimed at modeling flow induced damage of materials involving chemical reactions, deformation of the porous matrix, and complex flow phenomena. The numerical formulation is motivated by a mixture theory or theory of interacting continua type approach to coupling the behavior of the fluid and the porous matrix. Results for the proposed method are presented for several engineering problems of interest including carbon dioxide sequestration, hydraulic fracturing, and energetic materials applications. This work is intended to create a general framework for flow induced damage that can be further developed in each of the particular areas addressed below. The results show both convincing proof of the methodologies potential and the need for further validation of the models developed.

Turner, Daniel Zack

2012-01-01T23:59:59.000Z

430

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)  

E-Print Network (OSTI)

installation and initial water intake of the buffer over asaturated with water. Water intake is a slow process because

Steefel, Carl

2010-01-01T23:59:59.000Z

431

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)  

E-Print Network (OSTI)

3 deposition hole. Swedish Nuclear Fuel and Waste ManagementReport, 2008. Swedish Nuclear Fuel and Waste Managementoperated by the Swedish Nuclear Fuel and Waste Management

Steefel, Carl

2010-01-01T23:59:59.000Z

432

Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)  

E-Print Network (OSTI)

Sorption of Long-Lived Radionuclides Cesium-134, Strontium-term retardation of radionuclide release. EBS is involved inas heat release due to radionuclide decay, multiphase flow (

Steefel, Carl

2010-01-01T23:59:59.000Z

433

OVERVIEW OF PROPOSED TRANSPORTATION ENERGY  

E-Print Network (OSTI)

OVERVIEW OF PROPOSED TRANSPORTATION ENERGY ANALYSES FOR THE 2007 INTEGRATED ENERGY POLICY REPORT Jim Page, Malachi Weng-Gutierrez, and Gordon Schremp Fossil Fuels Office Fuels and Transportation....................................................................................................... 3 SUMMARY OF PROPOSED TRANSPORTATION ENERGY ANALYSES ............... 4 Background

434

Transportation activity analysis using smartphones  

E-Print Network (OSTI)

Transportation activity surveys investigate when, where and how people travel in urban areas to provide information necessary for urban transportation planning. In Singapore, the Land Transport Authority (LTA) carries out ...

Xiao, Yu

435

Tips: Transportation | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Tips: Transportation July 5, 2012 - 5:19pm Addthis Tips: Transportation In 2010, Americans traveled a total of 3 trillion miles -- the equivalent of 6.5 million...

436

Leslie Mancebo (7234) Transportation Demand &  

E-Print Network (OSTI)

Leslie Mancebo (7234) Transportation Demand & Marketing Coordinator 1 FTE, 1 HC Administrative Vice Chancellor Transportation and Parking Services Clifford A. Contreras (0245) Director 30.10 FTE Alternative Transportation & Marketing Reconciliation Lourdes Lupercio (4723) Michelle McArdle (7512) Parking

Hammock, Bruce D.

437

TRANSPORTATION POLICY AND ECONOMIC DEVELOPMENT  

E-Print Network (OSTI)

TRANSPORTATION POLICY AND ECONOMIC DEVELOPMENT: OUR CHOICE FOR THE FUTURE Proceedings from PROCEEDINGS North Dakota's Transportation Network: Our Choice for the Future Program Biographical Sketches PROCEEDINGS Transportation and Economic Development: Our Choice for the Future Program Biographical Sketches

Levinson, David M.

438

Mechanistic Reactive Burn Modeling of Solid Explosives  

SciTech Connect

This report describes a computational framework for reactive burn modeling of solid explosives and the development of a test case where physical mechanisms represent RDX or RDX-based materials. The report is a sequel to LA-13794-MS, ''A Unifying Framework for Hot Spots and the Ignition of Energetic Materials,'' where we proposed a new approach to the building of a general purpose model that captures the essential features of the three primary origins of hot-spot formation: void collapse, shear banding, friction. The purpose of the present report is to describe the continuing task of coupling the unifying hot-spot model to hydrodynamic calculations to develop a mechanistic reactive burn model. The key components of the coupling include energy localization, the growth of hot spots, overall hot-spot behavior, and a phase-averaged mixture equation of state (EOS) in a Mie-Grueneisen form. The nucleation and growth of locally heated regions is modeled by a phenomenological treatment as well as a statistical model based on an exponential size distribution. The Mie-Grueneisen form of the EOS is one of many possible choices and is not a critical selection for implementing the model. In this report, model calculations are limited to proof-of-concept illustrations for shock loading. Results include (1) shock ignition and growth-to-detonation, (2) double shock ignition, and (3) quenching and reignition. A comparative study of Pop-plots is discussed based on the statistical model.

Y.Horie; Y.Hamate; D.Greening

2003-04-01T23:59:59.000Z

439

Reactive thermal waves in energetic materials  

SciTech Connect

Reactive thermal waves (RTWs) arise in several energetic material applications, including self-propagating high-temperature synthesis (SHS), high explosive cookoff, and the detonation of heterogeneous explosives. In this paper I exmaine ideal RTWs, by which I mean that (1) material motion is neglected, (2) the state dependence of reaction is Arrhenius in the temperature, and (3) the reaction rate is modulated by an arbitrary mass-fraction-based reaction progress function. Numerical simulations demonstrate that one's natural intuition, which is based mainly upon experience with inert materials and which leads one to expect diffusion processes to become relatively slow after a short time period, is invalid for high energy, state-sensitive reactive systems. Instead, theory predicts that RTWs can propagate at very high speeds. This result agrees with estimates for detonating heterogeneous explosives, which indicate that RTWs must spread from hot-spot nucleation sites at rates comparable to the detonation speed in order to produce experimentally-observed reaction zone thicknesses. Using dimensionless scaling and further invoking the high activation energy approximation, I obtain an analytic formula for the steady plane RTW speed from numerical calculations. I then compute the RTW speed for real explosives, and discuss aspects of their behavior.

Hill, Larry G [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

440

Mild coal pretreatment to improve liquefaction reactivity  

SciTech Connect

This report describes work completed during the fifth quarter of a three year project to study the effects of mild chemical pretreatment on coal dissolution reactivity during low severity liquefaction or coal/oil coprocessing. The overall objective of this research is to elucidate changes in the chemical and physical structure of coal by pretreating with methanol or other simple organic solvent and a trace amount of hydrochloric acid and measure the influence of these changes on coal dissolution reactivity. Work this quarter focused on analytical characterization of untreated and treated Wyodak subbituminous coal and Illinois {number sign}6 bituminous coal. Mossbauer spectroscopy and x-ray diffraction techniques were used to study the effect of methanol/HCl pretreatment on the composition of each coal's inorganic phase. Results from these studies indicated that calcite is largely removed during pretreatment, but that other mineral species such as pyrite are unaffected. This finding is significant, since calcite removal appears to directly correlate with low severity liquefaction enhancement. Further work will be performed to study this phenomenon in more detail.

Miller, R.L.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reactive geochemical transport" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Argonne Transportation - Publications  

NLE Websites -- All DOE Office Websites (Extended Search)

Transportation Publications All downloadable documents on this site are in PDF format. You will need Adobe Reader to view these files (download Adobe Reader). Please note that some of these files are very large and may take some time to download. transforum TransForum The Center's quarterly newsletter featuring articles and photographs about current transportation research and breakthroughs. A 2011 STC Excellence Award winner. Subscribe to TransForum » factsheet icon Fact Sheets One sheet summaries on transportation topics and research argonne logo Recent Papers & Presentations Search for Papers, Presentations & More Find publications highlighting researcher work presented at conferences and other venues. Search by WORD or PHRASE Enter word or phrase

442

Colloid-Facilitated Transport of Radionuclides through the Vadose Zone  

SciTech Connect

The main purpose of this project was to advance the basic scientific understanding of colloid and colloid-facilitated Cs transport of radionuclides in the vadose zone. We focused our research on the hydrological and geochemical conditions beneath the leaking waste tanks at the USDOE Hanford reservation. Specific objectives were (1) to determine the lability and thermodynamic stability of colloidal materials, which form after reacting Hanford sediments with simulated Hanford Tank Waste, (2) to characterize the interactions between colloidal particles and contaminants, i.e., Cs and Eu, (3) to determine the potential of Hanford sediments for \\textit{in situ} mobilization of colloids, (4) to evaluate colloid-facilitated radionuclide transport through sediments under unsaturated flow, (5) to implement colloid-facilitated contaminant transport mechanisms into a transport model, and (6) to improve conceptual characterization of colloid-contaminant-soil interactions and colloid-facili\\-tated transport for clean-up procedures and long-term risk assessment. We have previously shown that upon contact with simulated waste tank solutions, Hanford sediments change their mineralogical composition. Certain minerals, i.e., quartz, smectite, and kaolinite, are partially dissolved, and new mineral phases, i.e., the feldspathoids cancrinite and sodalite, are formed. We have characterized these mineral transformations and clarified the mineral transformation pathways. The new minerals were mainly in the colloidal size fraction (diameter less than 2 mum), had a negative surface charge, and were microporous, meaning they contained small pores. When Cs was present during the formation of the minerals, contaminants, like Cs, could be trapped inside the mineral structure. Transport experiments under water saturated and unsaturated conditions showed that the colloids were mobile in Hanford sediments. As the water saturation of the sediments decreased, the amount of colloids transported also decreased. The colloids had the ability to enhance the migration of the radionuclide Cs; however, Cs initially sorbed to colloids was desorbed during transport through uncontaminated Hanford sediments. The finding that Cs was stripped off the colloids during the transport through uncontaminated sediments implies that colloids will likely not be an effective carrier for Cs, unless the Cs is incorporated into the mineral structure of the colloids such that the radionuclide cannot desorb from the colloids. Nevertheless, it appears that the amount of Cs that can be transported by mobile colloids beneath Hanford waste tanks is limited. Colloids will not be able to move the bulk mass of Cs through the vadose zone at Hanford. Colloid stability studies indicate that Hanford sediment form stable colloidal suspensions when suspended in Hanford sediment pore waters. Colloid stability was assessed by determination of the critical coagulation concentration, i.e., the chemical electrolyte concentration at which colloidal suspensions flocculate and settle out (become unstable). Although in the stable mode, Hanford colloids will settle out of solution after extended periods of time (months to years). Given the low recharge rates at Hanford range, which from near 0 to more than 100 mm/year, and the long travel times for rainwater to reach the groundwater of more than 40 years, it appears that colloidal transport is unlikely to occur if colloids are initially to be suspended close to the soil surface by infiltrating rainwater. However, if preferential flow or transient flow occurs, then colloidal transport may become more important. The results of this project have also led to improvements of our fundamental understanding of colloid transport and mobilization under unsaturated flow conditions in porous media. We have found that colloid attachment to the liquid-gas interface is not that relevant and that colloids rather attached near the triple phase interface where air, water, and solid phases meet. We have also found that capillary forces are the most dominant forces governing