National Library of Energy BETA

Sample records for modeling cycling units

  1. Steam Generator Component Model in a Combined Cycle of Power Conversion Unit for Very High Temperature Gas-Cooled Reactor

    SciTech Connect (OSTI)

    Oh, Chang H; Han, James; Barner, Robert; Sherman, Steven R

    2007-06-01

    The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP), Very High Temperature Gas-Cooled Reactor (VHTR) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. A combined cycle is considered as one of the power conversion units to be coupled to the very high-temperature gas-cooled reactor (VHTR). The combined cycle configuration consists of a Brayton top cycle coupled to a Rankine bottoming cycle by means of a steam generator. A detailed sizing and pressure drop model of a steam generator is not available in the HYSYS processes code. Therefore a four region model was developed for implementation into HYSYS. The focus of this study was the validation of a HYSYS steam generator model of two phase flow correlations. The correlations calculated the size and heat exchange of the steam generator. To assess the model, those calculations were input into a RELAP5 model and its results were compared with HYSYS results. The comparison showed many differences in parameters such as the heat transfer coefficients and revealed the different methods used by the codes. Despite differences in approach, the overall results of heat transfer were in good agreement.

  2. Modeling the Nuclear Fuel Cycle

    SciTech Connect (OSTI)

    Jacob J. Jacobson; A. M. Yacout; G. E. Matthern; S. J. Piet; A. Moisseytsev

    2005-07-01

    The Advanced Fuel Cycle Initiative is developing a system dynamics model as part of their broad systems analysis of future nuclear energy in the United States. The model will be used to analyze and compare various proposed technology deployment scenarios. The model will also give a better understanding of the linkages between the various components of the nuclear fuel cycle that includes uranium resources, reactor number and mix, nuclear fuel type and waste management. Each of these components is tightly connected to the nuclear fuel cycle but usually analyzed in isolation of the other parts. This model will attempt to bridge these components into a single model for analysis. This work is part of a multi-national laboratory effort between Argonne National Laboratory, Idaho National Laboratory and United States Department of Energy. This paper summarizes the basics of the system dynamics model and looks at some results from the model.

  3. Characterizing and Modelling Cycling Operations in Coal-fired...

    Gasoline and Diesel Fuel Update (EIA)

    Characterizing and Modeling Cycling Operations in Coal-fired Units June 2016 Chris Nichols ... Source: Kumar, N., et al, Power Plant Cycling Costs, NRELSR- 5500-55433 Most ...

  4. Duty Cycle Software Model

    Energy Science and Technology Software Center (OSTI)

    2010-12-31

    The Software consists of code which is capable of processing a large volume of data to create a “duty cycle” which is representative of how equipment will function under certain conditions.

  5. Simple ocean carbon cycle models

    SciTech Connect (OSTI)

    Caldeira, K.; Hoffert, M.I.; Siegenthaler, U.

    1994-02-01

    Simple ocean carbon cycle models can be used to calculate the rate at which the oceans are likely to absorb CO{sub 2} from the atmosphere. For problems involving steady-state ocean circulation, well calibrated ocean models produce results that are very similar to results obtained using general circulation models. Hence, simple ocean carbon cycle models may be appropriate for use in studies in which the time or expense of running large scale general circulation models would be prohibitive. Simple ocean models have the advantage of being based on a small number of explicit assumptions. The simplicity of these ocean models facilitates the understanding of model results.

  6. Integrated Climate and Carbon-cycle Model

    Energy Science and Technology Software Center (OSTI)

    2006-03-06

    The INCCA model is a numerical climate and carbon cycle modeling tool for use in studying climate change and carbon cycle science. The model includes atmosphere, ocean, land surface, and sea ice components.

  7. Emissions Modeling: GREET Life Cycle Analysis

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

    Emissions Modeling: GREET Life Cycle Analysis Michael Wang, Amgad Elgowainy, Jeongwoo Han ... Assumptions Approach: build LCA modeling capacity with the GREET model - Build a ...

  8. Cycling fossil-fired units proves costly business

    SciTech Connect (OSTI)

    Lefton, S.; Grimsrud, P.; Besuner, P.

    1997-07-01

    Competition in the electric utility business is having a far-reaching impact. Cost-cutting measures have in major downsizing efforts in virtually every utility in the country. After several cost-cutting rounds to reduce the low hanging fruit of inefficiency, utilities are still challenged to become leaner and meaner in order to compete in a deregulated environment. The problem for many power utilities, however, is they have not precisely determined their costs in every aspect of the plant`s operation. Naturally, obtaining an accurate understanding of expenditures is the starting point for utilities that wish to develop strategic plans to better manage assets, minimize costs and maximize return on investment better understand plant O&M costs and take measures to use this knowledge to their advantage. Cycling is a major reason for the increase in O&M costs of many fossil units. Cycling, in this context, refers to the operation of generating units at varying load levels in response to changes in system-load requirements.

  9. Technical Cost Modeling - Life Cycle Analysis Basis for Program...

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

    More Documents & Publications Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Life Cycle ...

  10. VISION: Verifiable Fuel Cycle Simulation Model

    SciTech Connect (OSTI)

    Jacob J. Jacobson; Abdellatif M. Yacout; Gretchen E. Matthern; Steven J. Piet; David E. Shropshire

    2009-04-01

    The nuclear fuel cycle is a very complex system that includes considerable dynamic complexity as well as detail complexity. In the nuclear power realm, there are experts and considerable research and development in nuclear fuel development, separations technology, reactor physics and waste management. What is lacking is an overall understanding of the entire nuclear fuel cycle and how the deployment of new fuel cycle technologies affects the overall performance of the fuel cycle. The Advanced Fuel Cycle Initiatives systems analysis group is developing a dynamic simulation model, VISION, to capture the relationships, timing and delays in and among the fuel cycle components to help develop an understanding of how the overall fuel cycle works and can transition as technologies are changed. This paper is an overview of the philosophy and development strategy behind VISION. The paper includes some descriptions of the model and some examples of how to use VISION.

  11. Theory, modeling and evaluations for the fuel cycle (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Theory, modeling and evaluations for the fuel cycle Citation Details In-Document Search Title: Theory, modeling and evaluations for the fuel cycle You are accessing a ...

  12. Theory, modeling and evaluations for the fuel cycle (Conference...

    Office of Scientific and Technical Information (OSTI)

    Theory, modeling and evaluations for the fuel cycle Citation Details In-Document Search Title: Theory, modeling and evaluations for the fuel cycle Authors: Talou, Patrick 1 + ...

  13. Technical Cost Modeling - Life Cycle Analysis Basis for Program...

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

    More Documents & Publications Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Polymer ...

  14. Technical Cost Modeling - Life Cycle Analysis Basis for Program...

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

    More Documents & Publications Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus ...

  15. Bioproduct Life Cycle Analysis with the GREETTM Model

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

    Bioproduct Life Cycle Analysis with the GREET TM Model Jennifer B. Dunn Biofuel Life Cycle Analysis Team Lead Systems Assessment Group Argonne National Laboratory Biomass 2014 July ...

  16. Bioproduct Life Cycle Analysis with the GREET Model | Department...

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

    Bioeconomy Bioproduct Life Cycle Analysis with the GREETTM Model Jennifer B. Dunn, Biofuel Life Cycle Analysis Team Lead, Argonne National Laboratory PDF icon ...

  17. A general simulation model for Stirling cycles

    SciTech Connect (OSTI)

    Schulz, S.; Schwendig, F.

    1996-01-01

    A mathematical model for the calculation of the Stirling cycle and of similar processes is presented. The model comprises a method to reproduce schematically any kind of process configuration, including free piston engines. The differential balance equations describing the process are solved by a stable integration algorithm. Heat transfer and pressure loss are calculated by using new correlations, which consider the special conditions of the periodic compression/expansion respectively of the oscillating flow. A comparison between experimental data achieved by means of a test apparatus and calculated data shows a good agreement.

  18. Impacts of Renewable Generation on Fossil Fuel Unit Cycling: Costs and Emissions (Presentation)

    SciTech Connect (OSTI)

    Brinkman, G.; Lew, D.; Denholm, P.

    2012-09-01

    Prepared for the Clean Energy Regulatory Forum III, this presentation looks at the Western Wind and Solar Integration Study and reexamines the cost and emissions impacts of fossil fuel unit cycling.

  19. Bioproduct Life Cycle Analysis with the GREET Model

    Office of Energy Efficiency and Renewable Energy (EERE)

    Breakout Session 2B—Integration of Supply Chains II: Bioproducts—Enabling Biofuels and Growing the Bioeconomy Bioproduct Life Cycle Analysis with the GREET Model Jennifer B. Dunn, Biofuel Life Cycle Analysis Team Lead, Argonne National Laboratory

  20. Cycle simulation of the low-temperature triple-effect absorption chiller with vapor compression unit

    SciTech Connect (OSTI)

    Kim, J.S.; Lee, H.

    1999-07-01

    The construction of a triple-effect absorption chiller machine using the lithium bromide-water solution as a working fluid is strongly limited by corrosion problems caused by the high generator temperature. In this work, three new cycles having the additional vapor compression units were suggested in order to lower the generator temperature of a triple-effect absorption chiller. Each new cycle has one compressor located at the different position which was used to elevate the pressure of the refrigerant vapor. Computer simulations were carried out in order to examine both the basic triple-effect cycle and three new cycles. All types of triple-effect absorption chiller cycles were found to be able to lower the temperature of high-temperature generator to the more favorable operation range. The COPs of three cycles calculated by considering the additional compressor works showed a small level of decrease or increase compared with that of the basic triple-effect cycle. Consequently, a low-temperature triple-effect absorption chiller can be possibly constructed by adapting one of three new cycles. A great advantage of these new cycles over the basic one is that the conventionally used lithium bromide-water solution can be successfully used as a working fluid without the danger of corrosion.

  1. Software Requirements Specification Verifiable Fuel Cycle Simulation (VISION) Model

    SciTech Connect (OSTI)

    D. E. Shropshire; W. H. West

    2005-11-01

    The purpose of this Software Requirements Specification (SRS) is to define the top-level requirements for a Verifiable Fuel Cycle Simulation Model (VISION) of the Advanced Fuel Cycle (AFC). This simulation model is intended to serve a broad systems analysis and study tool applicable to work conducted as part of the AFCI (including costs estimates) and Generation IV reactor development studies.

  2. Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus |

    Broader source: Energy.gov (indexed) [DOE]

    Department of Energy 1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation lm001_das_2011_o.pdf (305.88 KB) More Documents & Publications Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Technical Cost Modeling - Life Cycle Analysis Basis for Program Focus Multi-Material Joining: Challenges and Opportunities

  3. Fuel cycle assessment: A compendium of models, methodologies, and approaches

    SciTech Connect (OSTI)

    Not Available

    1994-07-01

    The purpose of this document is to profile analytical tools and methods which could be used in a total fuel cycle analysis. The information in this document provides a significant step towards: (1) Characterizing the stages of the fuel cycle. (2) Identifying relevant impacts which can feasibly be evaluated quantitatively or qualitatively. (3) Identifying and reviewing other activities that have been conducted to perform a fuel cycle assessment or some component thereof. (4) Reviewing the successes/deficiencies and opportunities/constraints of previous activities. (5) Identifying methods and modeling techniques/tools that are available, tested and could be used for a fuel cycle assessment.

  4. Organic carbon cycling in landfills: Model for a continuum approach

    SciTech Connect (OSTI)

    Bogner, J.; Lagerkvist, A.

    1997-09-01

    Organic carbon cycling in landfills can be addressed through a continuum model where the end-points are conventional anaerobic digestion of organic waste (short-term analogue) and geologic burial of organic material (long-term analogue). Major variables influencing status include moisture state, temperature, organic carbon loading, nutrient status, and isolation from the surrounding environment. Bioreactor landfills which are engineered for rapid decomposition approach (but cannot fully attain) the anaerobic digester end-point and incur higher unit costs because of their high degree of environmental isolation and control. At the other extreme, uncontrolled land disposal of organic waste materials is similar to geologic burial where organic carbon may be aerobically recycled to atmospheric CO{sub 2}, anaerobically converted to CH{sub 4} and CO{sub 2} during early diagenesis, or maintained as intermediate or recalcitrant forms into geologic time (> 1,000 years) for transformations via kerogen pathways. A family of improved landfill models are needed at several scales (molecular to landscape) which realistically address landfill processes and can be validated with field data.

  5. Internal cycle modeling and environmental assessment of multiple cycle consumer products

    SciTech Connect (OSTI)

    Tsiliyannis, C.A.

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Dynamic flow models are presented for remanufactured, reused or recycled products. Black-Right-Pointing-Pointer Early loss and stochastic return are included for fast and slow cycling products. Black-Right-Pointing-Pointer The reuse-to-input flow ratio (Internal Cycle Factor, ICF) is determined. Black-Right-Pointing-Pointer The cycle rate, which is increasing with the ICF, monitors eco-performance. Black-Right-Pointing-Pointer Early internal cycle losses diminish the ICF, the cycle rate and performance. - Abstract: Dynamic annual flow models incorporating consumer discard and usage loss and featuring deterministic and stochastic end-of-cycle (EOC) return by the consumer are developed for reused or remanufactured products (multiple cycle products, MCPs), including fast and slow cycling, short and long-lived products. It is shown that internal flows (reuse and overall consumption) increase proportionally to the dimensionless internal cycle factor (ICF) which is related to environmental impact reduction factors. The combined reuse/recycle (or cycle) rate is shown capable for shortcut, albeit effective, monitoring of environmental performance in terms of waste production, virgin material extraction and manufacturing impacts of all MCPs, a task, which physical variables (lifetime, cycling frequency, mean or total number of return trips) and conventional rates, via which environmental policy has been officially implemented (e.g. recycling rate) cannot accomplish. The cycle rate is shown to be an increasing (hyperbolic) function of ICF. The impact of the stochastic EOC return characteristics on total reuse and consumption flows, as well as on eco-performance, is assessed: symmetric EOC return has a small, positive effect on performance compared to deterministic, while early shifted EOC return is more beneficial. In order to be efficient, environmental policy should set higher minimum reuse targets for higher trippage MCPs. The

  6. Federal Register Notice for Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United States

    Broader source: Energy.gov [DOE]

    The Office of Fossil Energy of the Department of Energy gives notice of the availability of the report Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United...

  7. Steady-State Analysis Model for Advanced Fuel Cycle Schemes.

    Energy Science and Technology Software Center (OSTI)

    2008-03-17

    Version 00 SMAFS was developed as a part of the study, "Advanced Fuel Cycles and Waste Management", which was performed during 2003-2005 by an ad-hoc expert group under the Nuclear Development Committee in the OECD/NEA. The model was designed for an efficient conduct of nuclear fuel cycle scheme cost analyses. It is simple, transparent and offers users the capability to track down cost analysis results. All the fuel cycle schemes considered in the model aremore » represented in a graphic format and all values related to a fuel cycle step are shown in the graphic interface, i.e., there are no hidden values embedded in the calculations. All data on the fuel cycle schemes considered in the study including mass flows, waste generation, cost data, and other data such as activities, decay heat and neutron sources of spent fuel and high-level waste along time are included in the model and can be displayed. The user can easily modify values of mass flows and/or cost parameters and see corresponding changes in the results. The model calculates: front-end fuel cycle mass flows such as requirements of enrichment and conversion services and natural uranium; mass of waste based on the waste generation parameters and the mass flow; and all costs.« less

  8. Software Platform Evaluation - Verifiable Fuel Cycle Simulation (VISION) Model

    SciTech Connect (OSTI)

    J. J. Jacobson; D. E. Shropshire; W. B. West

    2005-11-01

    The purpose of this Software Platform Evaluation (SPE) is to document the top-level evaluation of potential software platforms on which to construct a simulation model that satisfies the requirements for a Verifiable Fuel Cycle Simulation Model (VISION) of the Advanced Fuel Cycle (AFC). See the Software Requirements Specification for Verifiable Fuel Cycle Simulation (VISION) Model (INEEL/EXT-05-02643, Rev. 0) for a discussion of the objective and scope of the VISION model. VISION is intended to serve as a broad systems analysis and study tool applicable to work conducted as part of the AFCI (including costs estimates) and Generation IV reactor development studies. This document will serve as a guide for selecting the most appropriate software platform for VISION. This is a “living document” that will be modified over the course of the execution of this work.

  9. Exhibit A: ENSR Modeling in Support of Individual Unit Operation |

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

    Department of Energy A: ENSR Modeling in Support of Individual Unit Operation Exhibit A: ENSR Modeling in Support of Individual Unit Operation Docket No. EO-05-01: Exhibit A: ENSR Modeling in Support of Individual Unit Operation, part of Supplement Number 3 to the Operating Plan of Mirant Potomac River, LLC Exhibit A: ENSR Modeling in Support of Individual Unit Operation (154.63 KB) More Documents & Publications Comments on Department of Energy's Emergency Order To Resume Limited

  10. Exhibit A: Modeling in Support of Two Unit Operating Configurations |

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

    Department of Energy Modeling in Support of Two Unit Operating Configurations Exhibit A: Modeling in Support of Two Unit Operating Configurations Docket No. EO-05-01: Tables showing modeling of emissions from units of the Mirant Potomac Power Plant. Exhibit A: Modeling in Support of Two Unit Operating Configurations (257.69 KB) More Documents & Publications Comments on Emergency Order to Resume Limited Operation at the Potomac River Generating Station, Alexandria, VA from the Chesapeake

  11. Integrated Gasification Combined Cycle (IGCC) demonstration project, Polk Power Station -- Unit No. 1. Annual report, October 1993--September 1994

    SciTech Connect (OSTI)

    1995-05-01

    This describes the Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project which will use a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,300 tons per day of coal (dry basis) coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 Btu/scf (LHV). The syngas then flows through a high temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product.

  12. VISION -- A Dynamic Model of the Nuclear Fuel Cycle

    SciTech Connect (OSTI)

    J. J. Jacobson; A. M. Yacout; S. J. Piet; D. E. Shropshire; G. E. Matthern

    2006-02-01

    The Advanced Fuel Cycle Initiative’s (AFCI) fundamental objective is to provide technology options that – if implemented – would enable long-term growth of nuclear power while improving sustainability and energy security. The AFCI organization structure consists of four areas; Systems Analysis, Fuels, Separations and Transmutations. The Systems Analysis Working Group is tasked with bridging the program technical areas and providing the models, tools, and analyses required to assess the feasibility of design and deploy¬ment options and inform key decision makers. An integral part of the Systems Analysis tool set is the development of a system level model that can be used to examine the implications of the different mixes of reactors, implications of fuel reprocessing, impact of deployment technologies, as well as potential “exit” or “off ramp” approaches to phase out technologies, waste management issues and long-term repository needs. The Verifiable Fuel Cycle Simulation Model (VISION) is a computer-based simulation model that allows performing dynamic simulations of fuel cycles to quantify infrastructure requirements and identify key trade-offs between alternatives. VISION is intended to serve as a broad systems analysis and study tool applicable to work conducted as part of the AFCI (including costs estimates) and Generation IV reactor development studies.

  13. Watts Bar Unit 1 Cycle Zero Power Physics Tests Analysis with VERA-CS

    SciTech Connect (OSTI)

    Gehin, Jess C; Godfrey, Andrew T; Evans, Thomas M; Hamilton, Steven P; Francheschini, F.

    2014-01-01

    The Consortium for Advanced Simulation of Light Water Reactors (CASL) is developing a collection of methods and software products known as VERA, the Virtual Environment for Reactor Applications, including a core simulation capability called VERA-CS. A key milestone for this endeavor is to validate VERA against measurements from operating nuclear power reactors. The first step in validation against plant data is to determine the ability of VERA to accurately simulate the initial startup physics tests for Watts Bar Nuclear Power Station, Unit 1 (WBN1) cycle 1. VERA-CS calculations were performed with the Insilico code developed at ORNL using cross section processing from the SCALE system and the transport capabilities within the Denovo transport code using the SPN method. The calculations were performed with ENDF/B-VII.0 cross sections in 252 groups (collapsed to 23 groups for the 3D transport solution). The key results of the comparison of calculations with measurements include initial criticality, control rod worth critical configurations, control rod worth, differential boron worth, and isothermal temperature reactivity coefficient (ITC). The VERA results for these parameters show good agreement with measurements, with the exception of the ITC, which requires additional investigation. Results are also compared to those obtained with Monte Carlo methods and a current industry core simulator.

  14. National Energy Modeling System (United States) | Open Energy...

    Open Energy Info (EERE)

    URI: cleanenergysolutions.orgcontentnational-energy-modeling-system-unite Language: English Policies: "Deployment Programs,Regulations" is not in the list of possible...

  15. Process integrated modelling for steelmaking Life Cycle Inventory analysis

    SciTech Connect (OSTI)

    Iosif, Ana-Maria Hanrot, Francois Ablitzer, Denis

    2008-10-15

    During recent years, strict environmental regulations have been implemented by governments for the steelmaking industry in order to reduce their environmental impact. In the frame of the ULCOS project, we have developed a new methodological framework which combines the process integrated modelling approach with Life Cycle Assessment (LCA) method in order to carry out the Life Cycle Inventory of steelmaking. In the current paper, this new concept has been applied to the sinter plant which is the most polluting steelmaking process. It has been shown that this approach is a powerful tool to make the collection of data easier, to save time and to provide reliable information concerning the environmental diagnostic of the steelmaking processes.

  16. Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model

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

    Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 New J. Phys. 11 013027 (http://iopscience.iop.org/1367-2630/11/1/013027) Download details: IP Address: 128.104.165.161 The article was downloaded on 14/12/2011 at 21:42 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections

  17. Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United States

    Broader source: Energy.gov [DOE]

    On May 29, 2014, the Department of Energy’s (DOE) Office of Fossil Energy announced the availability for public review and comment the report Life Cycle Greenhouse Gas Perspective on Exporting...

  18. Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United States

    Office of Energy Efficiency and Renewable Energy (EERE)

    This analysis calculates the life cycle greenhouse gas (GHG) emissions for regional coal and imported natural gas power in Europe and Asia. The primary research questions are as follows:...

  19. Development of a plant-wide dynamic model of an integrated gasification combined cycle (IGCC) plant

    SciTech Connect (OSTI)

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

    2009-01-01

    In this presentation, development of a plant-wide dynamic model of an advanced Integrated Gasification Combined Cycle (IGCC) plant with CO2 capture will be discussed. The IGCC reference plant generates 640 MWe of net power using Illinois No.6 coal as the feed. The plant includes an entrained, downflow, General Electric Energy (GEE) gasifier with a radiant syngas cooler (RSC), a two-stage water gas shift (WGS) conversion process, and two advanced 'F' class combustion turbines partially integrated with an elevated-pressure air separation unit (ASU). A subcritical steam cycle is considered for heat recovery steam generation. Syngas is selectively cleaned by a SELEXOL acid gas removal (AGR) process. Sulfur is recovered using a two-train Claus unit with tail gas recycle to the AGR. A multistage intercooled compressor is used for compressing CO2 to the pressure required for sequestration. Using Illinois No.6 coal, the reference plant generates 640 MWe of net power. The plant-wide steady-state and dynamic IGCC simulations have been generated using the Aspen Plus{reg_sign} and Aspen Plus Dynamics{reg_sign} process simulators, respectively. The model is generated based on the Case 2 IGCC configuration detailed in the study available in the NETL website1. The GEE gasifier is represented with a restricted equilibrium reactor model where the temperature approach to equilibrium for individual reactions can be modified based on the experimental data. In this radiant-only configuration, the syngas from the Radiant Syngas Cooler (RSC) is quenched in a scrubber. The blackwater from the scrubber bottom is further cleaned in the blackwater treatment plant. The cleaned water is returned back to the scrubber and also used for slurry preparation. The acid gas from the sour water stripper (SWS) is sent to the Claus plant. The syngas from the scrubber passes through a sour shift process. The WGS reactors are modeled as adiabatic plug flow reactors with rigorous kinetics based on the mid

  20. Integrating repositories with fuel cycles: The airport authority model

    SciTech Connect (OSTI)

    Forsberg, C.

    2012-07-01

    The organization of the fuel cycle is a legacy of World War II and the cold war. Fuel cycle facilities were developed and deployed without consideration of the waste management implications. This led to the fuel cycle model of a geological repository site with a single owner, a single function (disposal), and no other facilities on site. Recent studies indicate large economic, safety, repository performance, nonproliferation, and institutional incentives to collocate and integrate all back-end facilities. Site functions could include geological disposal of spent nuclear fuel (SNF) with the option for future retrievability, disposal of other wastes, reprocessing with fuel fabrication, radioisotope production, other facilities that generate significant radioactive wastes, SNF inspection (navy and commercial), and related services such as SNF safeguards equipment testing and training. This implies a site with multiple facilities with different owners sharing some facilities and using common facilities - the repository and SNF receiving. This requires a different repository site institutional structure. We propose development of repository site authorities modeled after airport authorities. Airport authorities manage airports with government-owned runways, collocated or shared public and private airline terminals, commercial and federal military facilities, aircraft maintenance bases, and related operations - all enabled and benefiting the high-value runway asset and access to it via taxi ways. With a repository site authority the high value asset is the repository. The SNF and HLW receiving and storage facilities (equivalent to the airport terminal) serve the repository, any future reprocessing plants, and others with needs for access to SNF and other wastes. Non-public special-built roadways and on-site rail lines (equivalent to taxi ways) connect facilities. Airport authorities are typically chartered by state governments and managed by commissions with members

  1. VHTR Prismatic Super Lattice Model for Equilibrium Fuel Cycle Analysis

    SciTech Connect (OSTI)

    G. S. Chang

    2006-09-01

    The advanced Very High Temperature gas-cooled Reactor (VHTR), which is currently being developed, achieves simplification of safety through reliance on innovative features and passive systems. One of the VHTRs innovative features is the reliance on ceramic-coated fuel particles to retain the fission products under extreme accident conditions. The effect of the random fuel kernel distribution in the fuel prismatic block is addressed through the use of the Dancoff correction factor in the resonance treatment. However, if the fuel kernels are not perfect black absorbers, the Dancoff correction factor is a function of burnup and fuel kernel packing factor, which requires that the Dancoff correction factor be updated during Equilibrium Fuel Cycle (EqFC) analysis. An advanced Kernel-by-Kernel (K-b-K) hexagonal super lattice model can be used to address and update the burnup dependent Dancoff effect during the EqFC analysis. The developed Prismatic Super Homogeneous Lattice Model (PSHLM) is verified by comparing the calculated burnup characteristics of the double-heterogeneous Prismatic Super Kernel-by-Kernel Lattice Model (PSK-b-KLM). This paper summarizes and compares the PSHLM and PSK-b-KLM burnup analysis study and results. This paper also discusses the coupling of a Monte-Carlo code with fuel depletion and buildup code, which provides the fuel burnup analysis tool used to produce the results of the VHTR EqFC burnup analysis.

  2. Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

    SciTech Connect (OSTI)

    B. Wayne Bequette; Priyadarshi Mahapatra

    2010-08-31

    The primary project objectives were to understand how the process design of an integrated gasification combined cycle (IGCC) power plant affects the dynamic operability and controllability of the process. Steady-state and dynamic simulation models were developed to predict the process behavior during typical transients that occur in plant operation. Advanced control strategies were developed to improve the ability of the process to follow changes in the power load demand, and to improve performance during transitions between power levels. Another objective of the proposed work was to educate graduate and undergraduate students in the application of process systems and control to coal technology. Educational materials were developed for use in engineering courses to further broaden this exposure to many students. ASPENTECH software was used to perform steady-state and dynamic simulations of an IGCC power plant. Linear systems analysis techniques were used to assess the steady-state and dynamic operability of the power plant under various plant operating conditions. Model predictive control (MPC) strategies were developed to improve the dynamic operation of the power plants. MATLAB and SIMULINK software were used for systems analysis and control system design, and the SIMULINK functionality in ASPEN DYNAMICS was used to test the control strategies on the simulated process. Project funds were used to support a Ph.D. student to receive education and training in coal technology and the application of modeling and simulation techniques.

  3. Response Surface Energy Modeling of an Electric Vehicle over a Reduced Composite Drive Cycle

    SciTech Connect (OSTI)

    Jehlik, Forrest; LaClair, Tim J.

    2014-04-01

    Response surface methodology (RSM) techniques were applied to develop a predictive model of electric vehicle (EV) energy consumption over the Environmental Protection Agency's (EPA) standardized drive cycles. The model is based on measurements from a synthetic composite drive cycle. The synthetic drive cycle is a minimized statistical composite of the standardized urban (UDDS), highway (HWFET), and US06 cycles. The composite synthetic drive cycle is 20 minutes in length thereby reducing testing time of the three standard EPA cycles by over 55%. Vehicle speed and acceleration were used as model inputs for a third order least squared regression model predicting vehicle battery power output as a function of the drive cycle. The approach reduced three cycles and 46 minutes of drive time to a single test of 20 minutes. Application of response surface modeling to the synthetic drive cycle is shown to predict energy consumption of the three EPA cycles within 2.6% of the actual measured values. Additionally, the response model may be used to predict energy consumption of any cycle within the speed/acceleration envelope of the synthetic cycle. This technique results in reducing test time, which additionally provides a model that may be used to expand the analysis and understanding of the vehicle under consideration.

  4. GREET Model Expanded to Better Address Biofuel Life-Cycle Analysis Research

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

    Questions | Department of Energy GREET Model Expanded to Better Address Biofuel Life-Cycle Analysis Research Questions GREET Model Expanded to Better Address Biofuel Life-Cycle Analysis Research Questions November 23, 2015 - 2:57pm Addthis GREET Model Expanded to Better Address Biofuel Life-Cycle Analysis Research Questions The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model allows researchers and analysts to fully evaluate the energy and emission

  5. Heavy Duty & Medium Duty Drive Cycle Data Collection for Modeling...

    Broader source: Energy.gov (indexed) [DOE]

    Program Truck Duty Cycle and Performance Data Collection and Analysis Program Vehicle Technologies Office Merit Review 2014: Powertrain Controls Optimization for Heavy Duty ...

  6. Sasse Modeling of First Cycle Neptunium (VI) Recovery Flowsheet

    SciTech Connect (OSTI)

    Laurinat, J. E.

    2006-04-01

    A flowsheet has been proposed to separate neptunium from solutions in H-Canyon Tanks 16.4, 12.5, and 11.7 in the First Cycle solvent extraction banks, in which cerium(IV) (Ce(IV)) serves as an agent to oxidize neptunium to neptunium(VI) (Np(VI)). A SASSE (Spreadsheet Algorithm for Stagewise Solvent Extraction) spreadsheet model indicates that the proposed flowsheet is a feasible method for separating neptunium and uranium from sulfates, thorium, and other metal impurities. The proposed flowsheet calls for stripping the sulfates, thorium, and other metal impurities into the 1AW stream and extracting and then stripping the neptunium and uranium into the 1BP stream. SASSE predicts that separation of thorium from the other actinides can be accomplished with actinide losses of 0.01% or less. It is assumed that other metal impurities such as iron, aluminum, and fission products will follow the thorium into 1AW. Due to an organic/aqueous distribution coefficient that is close to one, SASSE predicts that plutonium(VI) (Pu(VI)) is split between the A Bank and B Bank aqueous output streams, with 27% going to 1AW and 73% going to 1BP. An extrapolated distribution coefficient based on unvalidated Ce(IV) distribution measurements at a single nitrate concentration and a comparison with thorium(IV) (Th(IV)) distributions indicates that Ce(IV) could reflux in 1B Bank. If the Ce(IV) distribution coefficient is lower than would be predicted by this single point extrapolation, but still higher than the distribution coefficient for Th(IV), then Ce(IV) would follow Np(VI) and uranium(VI) (U(VI)) into 1BP. The SASSE model was validated using data from a 1964 oxidizing flowsheet for the recovery of Np(VI) in Second Cycle. For the proposed flowsheet to be effective in recovering neptunium, the addition of approximately 0.025 M ceric ammonium nitrate (Ce(NH4)2(NO3)6) to both the 1AF and 1AS streams is required to stabilize the neptunium in the +6

  7. Development and applications of GREET 2.7 -- The Transportation Vehicle-CycleModel.

    SciTech Connect (OSTI)

    Burnham, A.; Wang, M. Q.; Wu, Y.

    2006-12-20

    Argonne National Laboratory has developed a vehicle-cycle module for the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. The fuel-cycle GREET model has been cited extensively and contains data on fuel cycles and vehicle operations. The vehicle-cycle model evaluates the energy and emission effects associated with vehicle material recovery and production, vehicle component fabrication, vehicle assembly, and vehicle disposal/recycling. With the addition of the vehicle-cycle module, the GREET model now provides a comprehensive, lifecycle-based approach to compare the energy use and emissions of conventional and advanced vehicle technologies (e.g., hybrid electric vehicles and fuel cell vehicles). This report details the development and application of the GREET 2.7 model. The current model includes six vehicles--a conventional material and a lightweight material version of a mid-size passenger car with the following powertrain systems: internal combustion engine, internal combustion engine with hybrid configuration, and fuel cell with hybrid configuration. The model calculates the energy use and emissions that are required for vehicle component production; battery production; fluid production and use; and vehicle assembly, disposal, and recycling. This report also presents vehicle-cycle modeling results. In order to put these results in a broad perspective, the fuel-cycle model (GREET 1.7) was used in conjunction with the vehicle-cycle model (GREET 2.7) to estimate total energy-cycle results.

  8. Attachment A: Modeling in Support of Additional Two-Unit Operating...

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

    Attachment A: Modeling in Support of Additional Two-Unit Operating Configurations Attachment A: Modeling in Support of Additional Two-Unit Operating Configurations Docket No. ...

  9. Modeling Heavy/Medium-Duty Fuel Consumption Based on Drive Cycle Properties

    SciTech Connect (OSTI)

    Wang, Lijuan; Duran, Adam; Gonder, Jeffrey; Kelly, Kenneth

    2015-10-13

    This paper presents multiple methods for predicting heavy/medium-duty vehicle fuel consumption based on driving cycle information. A polynomial model, a black box artificial neural net model, a polynomial neural network model, and a multivariate adaptive regression splines (MARS) model were developed and verified using data collected from chassis testing performed on a parcel delivery diesel truck operating over the Heavy Heavy-Duty Diesel Truck (HHDDT), City Suburban Heavy Vehicle Cycle (CSHVC), New York Composite Cycle (NYCC), and hydraulic hybrid vehicle (HHV) drive cycles. Each model was trained using one of four drive cycles as a training cycle and the other three as testing cycles. By comparing the training and testing results, a representative training cycle was chosen and used to further tune each method. HHDDT as the training cycle gave the best predictive results, because HHDDT contains a variety of drive characteristics, such as high speed, acceleration, idling, and deceleration. Among the four model approaches, MARS gave the best predictive performance, with an average absolute percent error of -1.84% over the four chassis dynamometer drive cycles. To further evaluate the accuracy of the predictive models, the approaches were first applied to real-world data. MARS outperformed the other three approaches, providing an average absolute percent error of -2.2% of four real-world road segments. The MARS model performance was then compared to HHDDT, CSHVC, NYCC, and HHV drive cycles with the performance from Future Automotive System Technology Simulator (FASTSim). The results indicated that the MARS method achieved a comparative predictive performance with FASTSim.

  10. Modelling aging effects on a thermal cycling absorption process column

    SciTech Connect (OSTI)

    Laquerbe, C.; Contreras, S.; Demoment, J.

    2008-07-15

    Palladium coated on alumina is used in hydrogen separation systems operated at CEA/Valduc, and more particularly in Thermal Cycling Absorption Process columns. With such materials, tritium decay is known to induce aging effects which have direct side effects on hydrogen isotopes absorption isotherms. Furthermore in a TCAP column, aging occurs in an heterogeneous way. The possible impacts of these intrinsic material evolutions on the separation performances are investigated here through a numerical approach. (authors)

  11. Update 5 to: A Dispersion Modeling Analysis of Downwash from...

    Energy Savers [EERE]

    River Power Plant: Modeling Cycling Units 1, 2 plus One Baseload Unit Update 5 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant: Modeling ...

  12. Fuel-Cycle Energy and Emissions Analysis with the GREET Model | Department

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

    of Energy Fuel-Cycle Energy and Emissions Analysis with the GREET Model Fuel-Cycle Energy and Emissions Analysis with the GREET Model 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. ftp_02_wang.pdf (309.07 KB) More Documents & Publications GREET Development and Applications for Life-Cycle Analysis of Vehicle/Fuel Systems Well-to-Wheels Analysis of Advanced Fuel/Vehicle Systems - A North

  13. Multi-century Changes to Global Climate and Carbon Cycle: Results from a Coupled Climate and Carbon Cycle Model

    SciTech Connect (OSTI)

    Bala, G; Caldeira, K; Mirin, A; Wickett, M; Delire, C

    2005-02-17

    In this paper, we use a coupled climate and carbon cycle model to investigate the global climate and carbon cycle changes out to year 2300 that would occur if CO{sub 2} emissions from all the currently estimated fossil fuel resources were released to the atmosphere. By year 2300, the global climate warms by about 8 K and atmospheric CO{sub 2} reaches 1423 ppmv. The warming is higher than anticipated because the sensitivity to radiative forcing increases as the simulation progresses. In our simulation, the rate of emissions peak at over 30 PgC yr{sup -1} early in the 22nd century. Even at year 2300, nearly 50% of cumulative emissions remain in the atmosphere. In our simulations both soils and living biomass are net carbon sinks throughout the simulation. Despite having relatively low climate sensitivity and strong carbon uptake by the land biosphere, our model projections suggest severe long-term consequences for global climate if all the fossil-fuel carbon is ultimately released to the atmosphere.

  14. Steady state model of an industrial FCC unit

    SciTech Connect (OSTI)

    Lopez-Isunza, F.; Ancheyta-Juarez, J.

    1996-12-31

    A reactor model has been developed to simulate the steady-state of an industrial fluid catalytic cracking unit using a three-lump kinetic expression with parameters estimated from experiments in a microactivity test reactor. The model considers a transported bed reactor (riser) where gas-oil and catalyst are in contact to perform the endothermic cracking reactions, interacting with a two-phase moving bed regenerator with recirculation where the combustion of the coke deposited on the catalyst takes place. The model is used to find best operating conditions for maximizing gasoline yield in terms of gas-oil feed temperature (To) and recycled catalyst to gas-oil ratio (C/O). 12 refs., 4 figs.

  15. Thinking outside the channel: Modeling nitrogen cycling in networked river ecosystems

    SciTech Connect (OSTI)

    Helton, Ashley; Poole, Geoffrey C.; Meyer, Judy; Wollheim, Wilfred; Peterson, Bruce; Mulholland, Patrick J; Bernhardt, Emily; Stanford, Jack; Arango, Clay; Ashkenas, Linda; Cooper, Lee W; Dodds, Walter; Gregory, Stanley; Hall, Robert; Hamilton, Stephen; Johnson, Sherri; McDowell, William; Potter, Jody; Tank, Jennifer; Thomas, Suzanne; Valett, H. Maurice; Webster, Jackson; Zeglin, Lydia

    2011-01-01

    Agricultural and urban development alters nitrogen and other biogeochemical cycles in rivers worldwide. Because such biogeochemical processes cannot be measured empirically across whole river networks, simulation models are critical tools for understanding river-network biogeochemistry. However, limitations inherent in current models restrict our ability to simulate biogeochemical dynamics among diverse river networks. We illustrate these limitations using a river-network model to scale up in situ measures of nitrogen cycling in eight catchments spanning various geophysical and land-use conditions. Our model results provide evidence that catchment characteristics typically excluded from models may control river-network biogeochemistry. Based on our findings, we identify important components of a revised strategy for simulating biogeochemical dynamics in river networks, including approaches to modeling terrestrial-aquatic linkages, hydrologic exchanges between the channel, floodplain/riparian complex, and subsurface waters, and interactions between coupled biogeochemical cycles.

  16. Modeling long-term CO2 storage, sequestration and cycling

    SciTech Connect (OSTI)

    Bacon, Diana H.

    2013-11-11

    The application of numerical and analytical models to the problem of storage, sequestration and migration of carbon dioxide in geologic formations is discussed. A review of numerical and analytical models that have been applied to CO2 sequestration are presented, as well as a description of frameworks for risk analysis. Application of models to various issues related to carbon sequestration are discussed, including trapping mechanisms, density convection mixing, impurities in the CO2 stream, changes in formation porosity and permeability, the risk of vertical leakage, and the impacts on groundwater resources if leakage does occur. A discussion of the development and application of site-specific models first addresses the estimation of model parameters and the use of natural analogues to inform the development of CO2 sequestration models, and then surveys modeling that has been done at two commercial-scale CO2 sequestration sites, Sleipner and In Salah, along with a pilot-scale injection sites used to study CO2 sequestration in saline aquifers (Frio) and an experimental site designed to test monitoring of CO2 leakage in the vadose zone (ZERT Release Facility).

  17. User Guide for VISION 3.4.7 (Verifiable Fuel Cycle Simulation) Model

    SciTech Connect (OSTI)

    Jacob J. Jacobson; Robert F. Jeffers; Gretchen E. Matthern; Steven J. Piet; Wendell D. Hintze

    2011-07-01

    The purpose of this document is to provide a guide for using the current version of the Verifiable Fuel Cycle Simulation (VISION) model. This is a complex model with many parameters and options; the user is strongly encouraged to read this user guide before attempting to run the model. This model is an R&D work in progress and may contain errors and omissions. It is based upon numerous assumptions. This model is intended to assist in evaluating 'what if' scenarios and in comparing fuel, reactor, and fuel processing alternatives at a systems level. The model is not intended as a tool for process flow and design modeling of specific facilities nor for tracking individual units of fuel or other material through the system. The model is intended to examine the interactions among the components of a fuel system as a function of time varying system parameters; this model represents a dynamic rather than steady-state approximation of the nuclear fuel system. VISION models the nuclear cycle at the system level, not individual facilities, e.g., 'reactor types' not individual reactors and 'separation types' not individual separation plants. Natural uranium can be enriched, which produces enriched uranium, which goes into fuel fabrication, and depleted uranium (DU), which goes into storage. Fuel is transformed (transmuted) in reactors and then goes into a storage buffer. Used fuel can be pulled from storage into either separation or disposal. If sent to separations, fuel is transformed (partitioned) into fuel products, recovered uranium, and various categories of waste. Recycled material is stored until used by its assigned reactor type. VISION is comprised of several Microsoft Excel input files, a Powersim Studio core, and several Microsoft Excel output files. All must be co-located in the same folder on a PC to function. You must use Powersim Studio 8 or better. We have tested VISION with the Studio 8 Expert, Executive, and Education versions. The Expert and Education

  18. Microsoft Word - UPDATE 5 - Units 1,2 + base load unit.doc

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

    5 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant Modeling Cycling Units 1, 2 plus One Baseload Unit ENSR Corporation January 6, 2006 Document Number 10350-002-420 (Update 5) January, 2006 1-1 1.0 INTRODUCTION This report describes dispersion modeling performed for simultaneous operation of one baseload unit and two cycling units at Mirant's Potomac River Generating Station (PRGS). This mode of operation is also referred to as Option A in Mirant Potomac

  19. GREET 1.0 -- Transportation fuel cycles model: Methodology and use

    SciTech Connect (OSTI)

    Wang, M.Q.

    1996-06-01

    This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel-cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, Co, NOx, SOx, and particulate matter measuring 10 microns or less) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates the total fuel-cycle energy consumption, fossil fuel consumption, and petroleum consumption using various transportation fuels. The GREET model includes 17 fuel cycles: petroleum to conventional gasoline, reformulated gasoline, clean diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied petroleum gas, methanol, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydropower, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; and landfill gases to methanol. This report presents fuel-cycle energy use and emissions for a 2000 model-year car powered by each of the fuels that are produced from the primary energy sources considered in the study.

  20. A high-fidelity multiphysics model for the new solid oxide iron-air redox battery part I: Bridging mass transport and charge transfer with redox cycle kinetics

    SciTech Connect (OSTI)

    Jin, XF; Zhao, X; Huang, K

    2015-04-15

    A high-fidelity two-dimensional axial symmetrical multi-physics model is described in this paper as an effort to simulate the cycle performance of a recently discovered solid oxide metal-air redox battery (SOMARB). The model collectively considers mass transport, charge transfer and chemical redox cycle kinetics occurring across the components of the battery, and is validated by experimental data obtained from independent research. In particular, the redox kinetics at the energy storage unit is well represented by Johnson-Mehl-Avrami-Kolmogorov (JIVIAK) and Shrinking Core models. The results explicitly show that the reduction of Fe3O4 during the charging cycle limits the overall performance. Distributions of electrode potential, overpotential, Nernst potential, and H-2/H2O-concentration across various components of the battery are also systematically investigated. (C) 2015 Elsevier B.V. All rights reserved.

  1. Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States

    SciTech Connect (OSTI)

    Tessum, Christopher W.; Hill, Jason D.; Marshall, Julian D.

    2014-12-30

    Commonly considered strategies for reducing the environmental impact of light-duty transportation include using alternative fuels and improving vehicle fuel economy. We evaluate the air quality-related human health impacts of 10 such options, including the use of liquid biofuels, diesel, and compressed natural gas (CNG) in internal combustion engines; the use of electricity from a range of conventional and renewable sources to power electric vehicles (EVs); and the use of hybrid EV technology. Our approach combines spatially, temporally, and chemically detailed life cycle emission inventories; comprehensive, fine-scale state-of-the-science chemical transport modeling; and exposure, concentration–response, and economic health impact modeling for ozone (O3) and fine particulate matter (PM2.5). We find that powering vehicles with corn ethanol or with coal-based or “grid average” electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by low-emitting electricity from natural gas, wind, water, or solar power reduce environmental health impacts by 50% or more. Consideration of potential climate change impacts alongside the human health outcomes described here further reinforces the environmental preferability of EVs powered by low-emitting electricity relative to gasoline vehicles.

  2. Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States

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

    Tessum, Christopher W.; Hill, Jason D.; Marshall, Julian D.

    2014-12-30

    Commonly considered strategies for reducing the environmental impact of light-duty transportation include using alternative fuels and improving vehicle fuel economy. We evaluate the air quality-related human health impacts of 10 such options, including the use of liquid biofuels, diesel, and compressed natural gas (CNG) in internal combustion engines; the use of electricity from a range of conventional and renewable sources to power electric vehicles (EVs); and the use of hybrid EV technology. Our approach combines spatially, temporally, and chemically detailed life cycle emission inventories; comprehensive, fine-scale state-of-the-science chemical transport modeling; and exposure, concentration–response, and economic health impact modeling for ozonemore » (O3) and fine particulate matter (PM2.5). We find that powering vehicles with corn ethanol or with coal-based or “grid average” electricity increases monetized environmental health impacts by 80% or more relative to using conventional gasoline. Conversely, EVs powered by low-emitting electricity from natural gas, wind, water, or solar power reduce environmental health impacts by 50% or more. Consideration of potential climate change impacts alongside the human health outcomes described here further reinforces the environmental preferability of EVs powered by low-emitting electricity relative to gasoline vehicles.« less

  3. Modeling Lithium Movement over Multiple Cycles in a Lithium-Metal Battery

    SciTech Connect (OSTI)

    Ferrese, A; Newman, J

    2014-04-11

    This paper builds on the work by Ferrese et al. [J. Electrochem., 159, A1615 (2012)], where a model of a lithium-metal battery with a LiyCoO2 positive electrode was created in order to predict the movement of lithium in the negative electrode along the negative electrode/separator interface during cell cycling. In this paper, the model is expanded to study the movement of lithium along the lithium-metal anode over multiple cycles. From this model, it is found that when a low percentage of lithium at the negative electrode is utilized, the movement of lithium along the negative electrode/separator interface reaches a quasi steady state after multiple cycles. This steady state is affected by the slope of the open-circuit-potential function in the positive electrode, the rate of charge and discharge, the depth of discharge, and the length of the rest periods. However, when a high percent of the lithium at the negative electrode is utilized during cycling, the movement does not reach a steady state and pinching can occur, where the lithium nearest the negative tab becomes progressively thinner after cycling. This is another nonlinearity that leads to a progression of the movement of lithium over multiple cycles. (C) 2014 The Electrochemical Society.

  4. Evaluation of the Mesoscale Eta Model over the western United States. Master`s thesis

    SciTech Connect (OSTI)

    Swanson, R.T.

    1995-09-10

    The skill of the Mesoscale Eta Model is evaluated over a 6-month period from October 1, 1994 to March 31, 1995 over the western United States. This model will continue to undergo changes until and after its projected operational release in July 1995. Many diagnostics and error statistics are created to evaluate its performance as forecasts are received and archived at the University of Utah. These statistics are available on the Internet allowing researchers and operational forecasters access to them in near real-time. The Mesoscale Eta Model forecast initialized at 1200 UTC, 9 November 1994 is used as a case study to introduce many of the diagnostics developed to evaluate the model. A systematic evaluation of the average and root-mean-squared error over months and seasons reveals little significant bias in upper tropospheric fields such as 300 mb wind or 500 mb geopotential height. Moderate average errors are evident in lower tropospheric temperature. Accumulated precipitation over months and seasons indicates the model`s spinup of precipitation during the first 12 hours of the forecast cycle.

  5. United polarizable multipole water model for molecular mechanics simulation

    SciTech Connect (OSTI)

    Qi, Rui; Wang, Qiantao; Ren, Pengyu; Wang, Lee-Ping; Pande, Vijay S.

    2015-07-07

    We report the development of a united AMOEBA (uAMOEBA) polarizable water model, which is computationally 3–5 times more efficient than the three-site AMOEBA03 model in molecular dynamics simulations while providing comparable accuracy for gas-phase and liquid properties. In this coarse-grained polarizable water model, both electrostatic (permanent and induced) and van der Waals representations have been reduced to a single site located at the oxygen atom. The permanent charge distribution is described via the molecular dipole and quadrupole moments and the many-body polarization via an isotropic molecular polarizability, all located at the oxygen center. Similarly, a single van der Waals interaction site is used for each water molecule. Hydrogen atoms are retained only for the purpose of defining local frames for the molecular multipole moments and intramolecular vibrational modes. The parameters have been derived based on a combination of ab initio quantum mechanical and experimental data set containing gas-phase cluster structures and energies, and liquid thermodynamic properties. For validation, additional properties including dimer interaction energy, liquid structures, self-diffusion coefficient, and shear viscosity have been evaluated. The results demonstrate good transferability from the gas to the liquid phase over a wide range of temperatures, and from nonpolar to polar environments, due to the presence of molecular polarizability. The water coordination, hydrogen-bonding structure, and dynamic properties given by uAMOEBA are similar to those derived from the all-atom AMOEBA03 model and experiments. Thus, the current model is an accurate and efficient alternative for modeling water.

  6. Effects of soot-induced snow albedo change on snowpack and hydrological cycle in western United States based on Weather Research and Forecasting chemistry and regional climate simulations

    SciTech Connect (OSTI)

    Qian, Yun; Gustafson, William I.; Leung, Lai-Yung R.; Ghan, Steven J.

    2009-02-14

    Radiative forcing induced by soot on snow is a major anthropogenic forcing affecting the global climate. However, it is uncertain how the soot-induced snow albedo perturbation affects regional snowpack and the hydrological cycle. In this study we simulated the deposition of soot aerosol on snow and investigated the resulting impact on snowpack and the surface water budget in the western United States. A yearlong simulation was performed using the chemistry version of the Weather Research and Forecasting model (WRF-Chem) to determine an annual budget of soot deposition, followed by two regional climate simulations using WRF in meteorology-only mode, with and without the soot-induced snow albedo perturbations. The chemistry simulation shows large spatial variability in soot deposition that reflects the localized emissions and the influence of the complex terrain. The soot-induced snow albedo perturbations increase the net solar radiation flux at the surface during late winter to early spring, increase the surface air temperature, reduce snow water equivalent amount, and lead to reduced snow accumulation and less spring snowmelt. These effects are stronger over the central Rockies and southern Alberta, where soot deposition and snowpack overlap the most. The indirect forcing of soot accelerates snowmelt and alters stream flows, including a trend toward earlier melt dates in the western United States. The soot-induced albedo reduction initiates a positive feedback process whereby dirty snow absorbs more solar radiation, heating the surface and warming the air. This warming causes reduced snow depth and fraction, which further reduces the regional surface albedo for the snow covered regions. Our simulations indicate that the change of maximum snow albedo induced by soot on snow contributes to 60% of the net albedo reduction over the central Rockies. Snowpack reduction accounts for the additional 40%.

  7. Nuclear fuel cycle system simulation tool based on high-fidelity component modeling

    SciTech Connect (OSTI)

    Ames, David E.

    2014-02-01

    The DOE is currently directing extensive research into developing fuel cycle technologies that will enable the safe, secure, economic, and sustainable expansion of nuclear energy. The task is formidable considering the numerous fuel cycle options, the large dynamic systems that each represent, and the necessity to accurately predict their behavior. The path to successfully develop and implement an advanced fuel cycle is highly dependent on the modeling capabilities and simulation tools available for performing useful relevant analysis to assist stakeholders in decision making. Therefore a high-fidelity fuel cycle simulation tool that performs system analysis, including uncertainty quantification and optimization was developed. The resulting simulator also includes the capability to calculate environmental impact measures for individual components and the system. An integrated system method and analysis approach that provides consistent and comprehensive evaluations of advanced fuel cycles was developed. A general approach was utilized allowing for the system to be modified in order to provide analysis for other systems with similar attributes. By utilizing this approach, the framework for simulating many different fuel cycle options is provided. Two example fuel cycle configurations were developed to take advantage of used fuel recycling and transmutation capabilities in waste management scenarios leading to minimized waste inventories.

  8. A Computational Model for the Identification of Biochemical Pathways in the Krebs Cycle

    SciTech Connect (OSTI)

    Oliveira, Joseph S.; Bailey, Colin G.; Jones-Oliveira, Janet B.; Dixon, David A.; Gull, Dean W.; Chandler, Mary L.

    2003-03-01

    We have applied an algorithmic methodology which provably decomposes any complex network into a complete family of principal subcircuits to study the minimal circuits that describe the Krebs cycle. Every operational behavior that the network is capable of exhibiting can be represented by some combination of these principal subcircuits and this computational decomposition is linearly efficient. We have developed a computational model that can be applied to biochemical reaction systems which accurately renders pathways of such reactions via directed hypergraphs (Petri nets). We have applied the model to the citric acid cycle (Krebs cycle). The Krebs cycle, which oxidizes the acetyl group of acetyl CoA to CO2 and reduces NAD and FAD to NADH and FADH2 is a complex interacting set of nine subreaction networks. The Krebs cycle was selected because of its familiarity to the biological community and because it exhibits enough complexity to be interesting in order to introduce this novel analytic approach. This study validates the algorithmic methodology for the identification of significant biochemical signaling subcircuits, based solely upon the mathematical model and not upon prior biological knowledge. The utility of the algebraic-combinatorial model for identifying the complete set of biochemical subcircuits as a data set is demonstrated for this important metabolic process.

  9. A dynamic process model of a natural gas combined cycle -- Model development with startup and shutdown simulations

    SciTech Connect (OSTI)

    Liese, Eric; Zitney, Stephen E.

    2013-01-01

    Research in dynamic process simulation for integrated gasification combined cycles (IGCC) with carbon capture has been ongoing at the National Energy Technology Laboratory (NETL), culminating in a full operator training simulator (OTS) and immersive training simulator (ITS) for use in both operator training and research. A derivative work of the IGCC dynamic simulator has been a modification of the combined cycle section to more closely represent a typical natural gas fired combined cycle (NGCC). This paper describes the NGCC dynamic process model and highlights some of the simulator’s current capabilities through a particular startup and shutdown scenario.

  10. The FIT 2.0 Model - Fuel-cycle Integration and Tradeoffs

    SciTech Connect (OSTI)

    Steven J. Piet; Nick R. Soelberg; Layne F. Pincock; Eric L. Shaber; Gregory M Teske

    2011-06-01

    All mass streams from fuel separation and fabrication are products that must meet some set of product criteria – fuel feedstock impurity limits, waste acceptance criteria (WAC), material storage (if any), or recycle material purity requirements such as zirconium for cladding or lanthanides for industrial use. These must be considered in a systematic and comprehensive way. The FIT model and the “system losses study” team that developed it [Shropshire2009, Piet2010b] are steps by the Fuel Cycle Technology program toward an analysis that accounts for the requirements and capabilities of each fuel cycle component, as well as major material flows within an integrated fuel cycle. This will help the program identify near-term R&D needs and set longer-term goals. This report describes FIT 2, an update of the original FIT model.[Piet2010c] FIT is a method to analyze different fuel cycles; in particular, to determine how changes in one part of a fuel cycle (say, fuel burnup, cooling, or separation efficiencies) chemically affect other parts of the fuel cycle. FIT provides the following: Rough estimate of physics and mass balance feasibility of combinations of technologies. If feasibility is an issue, it provides an estimate of how performance would have to change to achieve feasibility. Estimate of impurities in fuel and impurities in waste as function of separation performance, fuel fabrication, reactor, uranium source, etc.

  11. Modeling Energy Recovery Using Thermoelectric Conversion Integrated with an Organic Rankine Bottoming Cycle

    SciTech Connect (OSTI)

    Miller, Erik W.; Hendricks, Terry J.; Peterson, Richard B.

    2009-07-01

    Hot engine exhaust represents a resource that is often rejected to the environment without further utilization. This resource is most prevalent in the transportation sector, but stationary engine-generator systems also typically do not utilize this resource. Engine exhaust is a source of high grade thermal energy that can potentially be utilized by various approaches to produce electricity or to drive heating and cooling systems. This paper describes a model system that employs thermoelectric conversion as a topping cycle integrated with an organic Rankine bottoming cycle for waste heat utilization. This approach is being developed to fully utilize the thermal energy contained in hot exhaust streams. The model is composed of a high temperature heat exchanger which extracts thermal energy for driving the thermoelectric conversion elements. However, substantial sensible heat remains in the exhaust stream after emerging from the heat exchanger. The model incorporates a closely integrated bottoming cycle to utilize this remaining thermal energy in the exhaust stream. The model has many interacting parameters that define combined system quantities such as overall output power, efficiency, and total energy utilization factors. In addition, the model identifies a maximum power operating point for the system. That is, the model can identify the optimal amount of heat to remove from the exhaust flow to run through the thermoelectric elements. Removing too much or too little heat from the exhaust stream in this stage will reduce overall cycle performance. The model has been developed such that heat exchanger UAh values, thermal resistances, ZT values, and multiple thermoelectric elements can be investigated in the context of system operation. The model also has the ability to simultaneously determine the effect of each cycle design parameter on the performance of the overall system, thus giving the ability to utilize as much waste heat as possible. Key analysis results are

  12. Update 1 to: A Dispersion Modeling Analysis of Downwash from...

    Broader source: Energy.gov (indexed) [DOE]

    Downwash from Mirant's Potomac River Power Plant, Modeling Unit 1 Emissions in a Cycling ... Downwash from Mirant's Potomac River Power Plant, Modeling Units 1 and 4 Together ...

  13. A life-cycle model approach to multimedia waste reduction measuring performance for environmental cleanup projects

    SciTech Connect (OSTI)

    Phifer, B.E. Jr.; George, S.M.

    1993-07-01

    The Martin Marietta Energy Systems, Inc. (Energy Systems), Environmental Restoration (ER) Program adopted a Pollution Prevention Program in March 1991. The program`s mission is to minimize waste and prevent pollution in remedial investigations (RIs), feasibility studies, decontamination and decommissioning, and surveillance and maintenance site program activities. Mission success will result in volume and/or toxicity reduction of generated waste. The ER Program waste generation rates are projected to steadily increase through the year 2005 for all waste categories. Standard production units utilized to measure waste minimization apply to production/manufacturing facilities. Since ER inherited contaminated waste from previous production processes, no historical production data can be applied. Therefore, a more accurate measure for pollution prevention was identified as a need for the ER Program. The Energy Systems ER Program adopted a life-cycle model approach and implemented the concept of numerically scoring their waste generators to measure the effectiveness of pollution prevention/waste minimization programs and elected to develop a numerical scoring system (NSS) to accomplish these measurements. The prototype NSS, a computerized, user-friendly information management database system, was designed to be utilized in each phase of the ER Program. The NSS was designed to measure a generator`s success in incorporating pollution prevention in their work plans and reducing investigation-derived waste (IDW) during RIs. Energy Systems is producing a fully developed NSS and actually scoring the generators of IDW at six ER Program sites. Once RI waste generators are scored utilizing the NSS, the numerical scores are distributed into six performance categories: training, self-assessment, field implementation, documentation, technology transfer, and planning.

  14. Evaluating the Diurnal Cycle of Upper Tropospheric Humidity in Two Different Climate Models Using Satellite Observations

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

    Kottayil, Ajil; John, Viju; Buehler, Stefan; Mohanakumar, Kesavapillai

    2016-04-13

    The diurnal cycle of upper tropospheric humidity (UTH) is known to be influenced by such processes as convection and the formation of clouds which are parameterized in current global climate models. In this study, we evaluate the performance of two climate models, the Community Atmospheric Model version 5 (CAM-5) and the Global Atmosphere 3.0 (GA-3) model in simulating the diurnal cycle of UTH (represented by a combination of sinusoids of 12 and 24 h periods) by comparing with microwave and infrared (IR) measurements (where available). These comparisons were made over two convective land regions in South America and Africa, andmore » over oceanic regions in the Atlantic, Indian and West Pacific for the month of January 2007. We analyzed how the diurnal cycles from IR and microwave instruments differ, and the reason for the differences. Our study suggests that the differences in the diurnal cycles of IR and microwave UTH result from sampling differences due to the presence of clouds. Lastly, as noted by earlier studies, the models exhibit considerable discrepancies in diurnal amplitude and phase relative to observations, and these discrepancies have different magnitudes over land and ocean.« less

  15. Global Biogeochemistry Models and Global Carbon Cycle Research at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Covey, C; Caldeira, K; Guilderson, T; Cameron-Smith, P; Govindasamy, B; Swanston, C; Wickett, M; Mirin, A; Bader, D

    2005-05-27

    The climate modeling community has long envisioned an evolution from physical climate models to ''earth system'' models that include the effects of biology and chemistry, particularly those processes related to the global carbon cycle. The widely reproduced Box 3, Figure 1 from the 2001 IPCC Scientific Assessment schematically describes that evolution. The community generally accepts the premise that understanding and predicting global and regional climate change requires the inclusion of carbon cycle processes in models to fully simulate the feedbacks between the climate system and the carbon cycle. Moreover, models will ultimately be employed to predict atmospheric concentrations of CO{sub 2} and other greenhouse gases as a function of anthropogenic and natural processes, such as industrial emissions, terrestrial carbon fixation, sequestration, land use patterns, etc. Nevertheless, the development of coupled climate-carbon models with demonstrable quantitative skill will require a significant amount of effort and time to understand and validate their behavior at both the process level and as integrated systems. It is important to consider objectively whether the currently proposed strategies to develop and validate earth system models are optimal, or even sufficient, and whether alternative strategies should be pursued. Carbon-climate models are going to be complex, with the carbon cycle strongly interacting with many other components. Off-line process validation will be insufficient. As was found in coupled atmosphere-ocean GCMs, feedbacks between model components can amplify small errors and uncertainties in one process to produce large biases in the simulated climate. The persistent tropical western Pacific Ocean ''double ITCZ'' and upper troposphere ''cold pole'' problems are examples. Finding and fixing similar types of problems in coupled carbon-climate models especially will be difficult, given the lack of observations required for diagnosis and validation

  16. Sensor placement algorithm development to maximize the efficiency of acid gas removal unit for integrated gasification combined cycle (IGCC) power plant with CO{sub 2} capture

    SciTech Connect (OSTI)

    Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2012-01-01

    Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel

  17. Modeling and Simulations for the High Flux Isotope Reactor Cycle 400

    SciTech Connect (OSTI)

    Ilas, Germina; Chandler, David; Ade, Brian J; Sunny, Eva E; Betzler, Benjamin R; Pinkston, Daniel

    2015-03-01

    A concerted effort over the past few years has been focused on enhancing the core model for the High Flux Isotope Reactor (HFIR), as part of a comprehensive study for HFIR conversion from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel. At this time, the core model used to perform analyses in support of HFIR operation is an MCNP model for the beginning of Cycle 400, which was documented in detail in a 2005 technical report. A HFIR core depletion model that is based on current state-of-the-art methods and nuclear data was needed to serve as reference for the design of an LEU fuel for HFIR. The recent enhancements in modeling and simulations for HFIR that are discussed in the present report include: (1) revision of the 2005 MCNP model for the beginning of Cycle 400 to improve the modeling data and assumptions as necessary based on appropriate primary reference sources HFIR drawings and reports; (2) improvement of the fuel region model, including an explicit representation for the involute fuel plate geometry that is characteristic to HFIR fuel; and (3) revision of the Monte Carlo-based depletion model for HFIR in use since 2009 but never documented in detail, with the development of a new depletion model for the HFIR explicit fuel plate representation. The new HFIR models for Cycle 400 are used to determine various metrics of relevance to reactor performance and safety assessments. The calculated metrics are compared, where possible, with measurement data from preconstruction critical experiments at HFIR, data included in the current HFIR safety analysis report, and/or data from previous calculations performed with different methods or codes. The results of the analyses show that the models presented in this report provide a robust and reliable basis for HFIR analyses.

  18. Modeling the role of terrestrial ecosystems in the global carbon cycle

    SciTech Connect (OSTI)

    Emanuel, W.R.; Post, W.M.; Shugart, H.H. Jr.

    1980-01-01

    A model for the global biogeochemical cycle of carbon which includes a five-compartment submodel for circulation in terrestrial ecosystems of the world is presented. Although this terrestrial submodel divides carbon into compartments with more functional detail than previous models, the variability in carbon dynamics among ecosystem types and in different climatic zones is not adequately treated. A new model construct which specifically treats this variability by modeling the distribution of ecosystem types as a function of climate on a 0.5/sup 0/ latitude by 0.5/sup 0/ longitude scale of resolution is proposed.

  19. Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model

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

    Letscher, R. T.; Moore, J. K.; Teng, Y. -C.; Primeau, F.

    2015-01-12

    Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a fact that is often omitted from biogeochemical ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observationalmore » data coverage and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C : N : P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model (CESM) and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr-1 (143 Tmol C yr-1, 16.4 Tmol N yr-1, and 1 Tmol P yr-1, respectively, with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. Dissolved organic carbon (DOC) export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less

  20. Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model

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

    Letscher, R. T.; Moore, J. K.; Teng, Y. -C.; Primeau, F.

    2014-06-16

    Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a~fact that is often omitted from biogeochemical-ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observational data coveragemore » and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C / N / P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr-1 (143 Tmol C yr-1), 16.4 Tmol N yr-1, and 1 Tmol P yr-1, respectively with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. DOC export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less

  1. Attachment A: Modeling in Support of Additional Two-Unit Operating

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

    Configurations | Department of Energy Attachment A: Modeling in Support of Additional Two-Unit Operating Configurations Attachment A: Modeling in Support of Additional Two-Unit Operating Configurations Docket No. EO-05-01: Attachment to the Operating Plan of Mirant Potomac River, LLC Attachment A: Modeling in Support of Additional Two-Unit Operating Configurations (28.18 KB) More Documents & Publications Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME

  2. Update 5 to: A Dispersion Modeling Analysis of Downwash from Mirant's

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

    Potomac River Power Plant: Modeling Cycling Units 1, 2 plus One Baseload Unit | Department of Energy 5 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant: Modeling Cycling Units 1, 2 plus One Baseload Unit Update 5 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant: Modeling Cycling Units 1, 2 plus One Baseload Unit Docket No. EO-05-01: This report describes dispersion modeling performed for simultaneous operation of one

  3. An Updated Central and Eastern United States Ground-Motion Model |

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

    Department of Energy An Updated Central and Eastern United States Ground-Motion Model An Updated Central and Eastern United States Ground-Motion Model An Updated Central and Eastern United States Ground-Motion Model Lawrence Salomone Pinnacle Specialty Group, Inc. DOE NPH Meeting October 21-22, 2014 An Updated Central and Eastern United States Ground-Motion Model (1.89 MB) More Documents & Publications A Probabilistic Seismic Hazard Analysis Update Review for Two DOE Sites and NGA-East

  4. Development of a Scale Model for High Flux Isotope Reactor Cycle 400

    SciTech Connect (OSTI)

    Ilas, Dan

    2012-03-01

    The development of a comprehensive SCALE computational model for the High Flux Isotope Reactor (HFIR) is documented and discussed in this report. The SCALE model has equivalent features and functionality as the reference MCNP model for Cycle 400 that has been used extensively for HFIR safety analyses and for HFIR experiment design and analyses. Numerical comparisons of the SCALE and MCNP models for the multiplication constant, power density distribution in the fuel, and neutron fluxes at several locations in HFIR indicate excellent agreement between the results predicted with the two models. The SCALE HFIR model is presented in sufficient detail to provide the users of the model with a tool that can be easily customized for various safety analysis or experiment design requirements.

  5. Ocean Carbon Cycle Models from the Carbon Dioxide Information Analysis Center (CDIAC)

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

    The following Ocean Carbon Cycle models and modeling results are available from CDIAC: • CSIRO/Matear Data [Model simulation of climate change from 1880 till 2100 (Matear and Hirst 2003, GBC) • Lequere Data, Model Results • McKinley MITgcm offline biogeochemical model - posted May 2004 • McKinley MITgcm offline biogeochemical model - posted December 2004 • NCOM-Pacific-Biogeochemical Modeling Results from Fei Chai • ROMS-Pacific-Biogeochemical Modeling Results from Fei CHai • WHOI/NCAR/Irvine Eco-BGC (Doney, Moore, Lindsay, and Lima) - Posted May 2005 • Max-Planck-Institut f?r Biogeochemie (Lequere, Buitenhuis) Modeling Results • Max-Planck-Institut f?r Biogeochemie (Lequere, Buitenhuis) Modeling Results - Posted March 2005 • Jim Christian model output for (a) Climatologies of T, S, PO4 at 50 m depth intervals; (b) SST, SSS, MLD, pCO2, CO2 flux from 1990-2003, and (c) climatological surface horizontal velocity • Max-Planck-Institut f?r Biogeochemie (Lequere, Buitenhuis) Modeling Results • Deutsch (UW) model output results for Oxygen variability in the North Pacific • Pacific data-model intercomparison from Patrick Wetzel (Max Planck Institute for Meteorology, Germany)

  6. SOLAR MAGNETIC ACTIVITY CYCLES, CORONAL POTENTIAL FIELD MODELS AND ERUPTION RATES

    SciTech Connect (OSTI)

    Petrie, G. J. D.

    2013-05-10

    We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the National Solar Observatory's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun vector spectro-magnetograph, the spectro-magnetograph and the 512-channel magnetograph instruments, and from Stanford University's Wilcox Solar Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Polar field changes are found to be well correlated with active fields over most of the period studied, except between 2003 and 2006 when the active fields did not produce significant polar field changes. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the activity cycle. All non-axisymmetric multipole strengths are well correlated with the activity cycle. The tilt of the solar dipole is therefore almost entirely due to active-region fields. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This influence of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking, Solar Eruptive Event Detection System, and Nobeyama radioheliograph prominence eruption catalogs, the rate of solar eruptions is found to be systematically higher for active years between 2003 and 2012 than for those between 1997 and 2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.

  7. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

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

    Archer, D.

    2014-06-03

    A two-dimensional model of a passive continental margin was adapted to the simulation of the methane cycle on Siberian continental shelf and slope, attempting to account for the impacts of glacial/interglacial cycles in sea level, alternately exposing the continental shelf to freezing conditions with deep permafrost formation during glacial times, and immersion in the ocean in interglacial times. The model is used to gauge the impact of the glacial cycles, and potential anthropogenic warming in the deep future, on the atmospheric methane emission flux, and the sensitivities of that flux to processes such as permafrost formation and terrestrial organic carbonmore » (Yedoma) deposition. Hydrological forcing drives a freshening and ventilation of pore waters in areas exposed to the atmosphere, which is not quickly reversed by invasion of seawater upon submergence, since there is no analogous saltwater pump. This hydrological pump changes the salinity enough to affect the stability of permafrost and methane hydrates on the shelf. Permafrost formation inhibits bubble transport through the sediment column, by construction in the model. The impact of permafrost on the methane budget is to replace the bubble flux by offshore groundwater flow containing dissolved methane, rather than accumulating methane for catastrophic release when the permafrost seal fails during warming. By far the largest impact of the glacial/interglacial cycles on the atmospheric methane flux is attenuation by dissolution of bubbles in the ocean when sea level is high. Methane emissions are highest during the regression (soil freezing) part of the cycle, rather than during transgression (thawing). The model-predicted methane flux to the atmosphere in response to a warming climate is small, relative to the global methane production rate, because of the ongoing flooding of the continental shelf. A slight increase due to warming could be completely counteracted by sea level rise on geologic time

  8. Energy flow, nutrient cycling, and ecosystem resilience

    SciTech Connect (OSTI)

    DeAngelis, D.L.

    1980-08-01

    The resilience, defined here as the speed with which a system returns to equilibrium state following a perturbation, is investigated for both food web energy models and nutrient cycling models. Previous simulation studies of food web energy models have shown that resilience increases as the flux of energy through the food web per unit amount of energy in the steady state web increases. Studies of nutrient cycling models have shown that resilience increases as the mean number of cycles that nutrient (or other mineral) atoms make before leaving the system decreases. In the present study these conclusions are verified analytically for general ecosystem models. The behavior of resilience in food web energy models and nutrient cycling models is a reflection of the time that a given unit, whether of energy or matter, spends in the steady state system. The shorter this residence time is, the more resilient the system is.

  9. Updated Life-Cycle Assessment of Aluminum Production and Semi-fabrication for the GREET Model

    SciTech Connect (OSTI)

    Dai, Qiang; Kelly, Jarod C.; Burnham, Andrew; Elgowainy, Amgad

    2015-09-01

    This report serves as an update for the life-cycle analysis (LCA) of aluminum production based on the most recent data representing the state-of-the-art of the industry in North America. The 2013 Aluminum Association (AA) LCA report on the environmental footprint of semifinished aluminum products in North America provides the basis for the update (The Aluminum Association, 2013). The scope of this study covers primary aluminum production, secondary aluminum production, as well as aluminum semi-fabrication processes including hot rolling, cold rolling, extrusion and shape casting. This report focuses on energy consumptions, material inputs and criteria air pollutant emissions for each process from the cradle-to-gate of aluminum, which starts from bauxite extraction, and ends with manufacturing of semi-fabricated aluminum products. The life-cycle inventory (LCI) tables compiled are to be incorporated into the vehicle cycle model of Argonne National Laboratory’s Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model for the release of its 2015 version.

  10. Waste Classification based on Waste Form Heat Generation in Advanced Nuclear Fuel Cycles Using the Fuel-Cycle Integration and Tradeoffs (FIT) Model

    SciTech Connect (OSTI)

    Denia Djokic; Steven J. Piet; Layne F. Pincock; Nick R. Soelberg

    2013-02-01

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. This analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. The value of separation of heat-generating fission products and actinides in different fuel cycles is discussed. It was shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system , and that it is useful to classify waste streams based on how favorable the impact of interim storage is in increasing repository capacity.

  11. Waste Classification based on Waste Form Heat Generation in Advanced Nuclear Fuel Cycles Using the Fuel-Cycle Integration and Tradeoffs (FIT) Model - 13413

    SciTech Connect (OSTI)

    Djokic, Denia [Department of Nuclear Engineering, University of California - Berkeley, 4149 Etcheverry Hall, Berkeley, CA 94720-1730 (United States)] [Department of Nuclear Engineering, University of California - Berkeley, 4149 Etcheverry Hall, Berkeley, CA 94720-1730 (United States); Piet, Steven J.; Pincock, Layne F.; Soelberg, Nick R. [Idaho National Laboratory - INL, 2525 North Fremont Avenue, Idaho Falls, ID 83415 (United States)] [Idaho National Laboratory - INL, 2525 North Fremont Avenue, Idaho Falls, ID 83415 (United States)

    2013-07-01

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. This analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. The value of separation of heat-generating fission products and actinides in different fuel cycles is discussed. It was shown that the benefits of reducing the short-term fission-product heat load of waste destined for geologic disposal are neglected under the current source-based radioactive waste classification system, and that it is useful to classify waste streams based on how favorable the impact of interim storage is in increasing repository capacity. (authors)

  12. Reviews and syntheses: Four decades of modeling methane cycling in terrestrial ecosystems

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

    Xu, Xiaofeng; Yuan, Fengming; Hanson, Paul J.; Wullschleger, Stan D.; Thornton, Peter E.; Riley, William J.; Song, Xia; Graham, David E.; Song, Changchun; Tian, Hanqin

    2016-06-28

    Over the past 4 decades, a number of numerical models have been developed to quantify the magnitude, investigate the spatial and temporal variations, and understand the underlying mechanisms and environmental controls of methane (CH4) fluxes within terrestrial ecosystems. These CH4 models are also used for integrating multi-scale CH4 data, such as laboratory-based incubation and molecular analysis, field observational experiments, remote sensing, and aircraft-based measurements across a variety of terrestrial ecosystems. Here we summarize 40 terrestrial CH4 models to characterize their strengths and weaknesses and to suggest a roadmap for future model improvement and application. Our key findings are that (1) themore » focus of CH4 models has shifted from theoretical to site- and regional-level applications over the past 4 decades, (2) large discrepancies exist among models in terms of representing CH4 processes and their environmental controls, and (3) significant data–model and model–model mismatches are partially attributed to different representations of landscape characterization and inundation dynamics. Three areas for future improvements and applications of terrestrial CH4 models are that (1) CH4 models should more explicitly represent the mechanisms underlying land–atmosphere CH4 exchange, with an emphasis on improving and validating individual CH4 processes over depth and horizontal space, (2) models should be developed that are capable of simulating CH4 emissions across highly heterogeneous spatial and temporal scales, particularly hot moments and hotspots, and (3) efforts should be invested to develop model benchmarking frameworks that can easily be used for model improvement, evaluation, and integration with data from molecular to global scales. These improvements in CH4 models would be beneficial for the Earth system models and further simulation of climate–carbon cycle feedbacks.« less

  13. Reviews and syntheses: Four decades of modeling methane cycling in terrestrial ecosystems

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

    Xu, Xiaofeng; Yuan, Fengming; Hanson, Paul J.; Wullschleger, Stan D.; Thornton, Peter E.; Riley, William J.; Song, Xia; Graham, David E.; Song, Changchun; Tian, Hanqin

    2016-01-28

    A number of numerical models have been developed to quantify the magnitude, over the past 4 decades, such that we have investigated the spatial and temporal variations, and understand the underlying mechanisms and environmental controls of methane (CH4) fluxes within terrestrial ecosystems. These CH4 models are also used for integrating multi-scale CH4 data, such as laboratory-based incubation and molecular analysis, field observational experiments, remote sensing, and aircraft-based measurements across a variety of terrestrial ecosystems. Here we summarize 40 terrestrial CH4 models to characterize their strengths and weaknesses and to suggest a roadmap for future model improvement and application. Our keymore » findings are that (1) the focus of CH4 models has shifted from theoretical to site- and regional-level applications over the past 4 decades, (2) large discrepancies exist among models in terms of representing CH4 processes and their environmental controls, and (3) significant data–model and model–model mismatches are partially attributed to different representations of landscape characterization and inundation dynamics. Furthermore three areas for future improvements and applications of terrestrial CH4 models are that (1) CH4 models should more explicitly represent the mechanisms underlying land–atmosphere CH4 exchange, with an emphasis on improving and validating individual CH4 processes over depth and horizontal space, (2) models should be developed that are capable of simulating CH4 emissions across highly heterogeneous spatial and temporal scales, particularly hot moments and hotspots, and (3) efforts should be invested to develop model benchmarking frameworks that can easily be used for model improvement, evaluation, and integration with data from molecular to global scales. Finally, these improvements in CH4 models would be beneficial for the Earth system models and further simulation of climate–carbon cycle feedbacks.« less

  14. MODELING THE DEMAND FOR E85 IN THE UNITED STATES

    SciTech Connect (OSTI)

    Liu, Changzheng; Greene, David L

    2013-10-01

    How demand for E85 might evolve in the future in response to changing economics and policies is an important subject to include in the National Energy Modeling System (NEMS). This report summarizes a study to develop an E85 choice model for NEMS. Using the most recent data from the states of Minnesota, North Dakota, and Iowa, this study estimates a logit model that represents E85 choice as a function of prices of E10 and E85, as well as fuel availability of E85 relative to gasoline. Using more recent data than previous studies allows a better estimation of non-fleet demand and indicates that the price elasticity of E85 choice appears to be higher than previously estimated. Based on the results of the econometric analysis, a model for projecting E85 demand at the regional level is specified. In testing, the model produced plausible predictions of US E85 demand to 2040.

  15. VERA Modeling and Simulation of the AP1000 PWR Cycle 1 Depletion

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

    CASL-U-2015-0302-000 VERA Modeling and Simulation of the AP1000 PWR Cycle 1 Depletion L3:VMA.AMA.P11.06 David Salazar, Westinghouse Fausto Franceschini, Westinghouse September 30, 2015 L3:VMA.AMA.P11.06 Official Use Only ii Protected under CASL Master NDA CASL-U-2015-0302-000 REVISION LOG Revision Date Affected Pages Revision Description 0 09/30/2015 All Initial issuance Document pages that are: Export Controlled ____________No______________________________________ IP/Proprietary/NDA

  16. Fuel cycle cost uncertainty from nuclear fuel cycle comparison

    SciTech Connect (OSTI)

    Li, J.; McNelis, D.; Yim, M.S.

    2013-07-01

    This paper examined the uncertainty in fuel cycle cost (FCC) calculation by considering both model and parameter uncertainty. Four different fuel cycle options were compared in the analysis including the once-through cycle (OT), the DUPIC cycle, the MOX cycle and a closed fuel cycle with fast reactors (FR). The model uncertainty was addressed by using three different FCC modeling approaches with and without the time value of money consideration. The relative ratios of FCC in comparison to OT did not change much by using different modeling approaches. This observation was consistent with the results of the sensitivity study for the discount rate. Two different sets of data with uncertainty range of unit costs were used to address the parameter uncertainty of the FCC calculation. The sensitivity study showed that the dominating contributor to the total variance of FCC is the uranium price. In general, the FCC of OT was found to be the lowest followed by FR, MOX, and DUPIC. But depending on the uranium price, the FR cycle was found to have lower FCC over OT. The reprocessing cost was also found to have a major impact on FCC.

  17. Life Cycle Environmental Impacts Resulting from the Manufacture of the Heliostat Field for a Reference Power Tower Design in the United States: Preprint

    SciTech Connect (OSTI)

    Heath, G.; Burkhardt, J.; Turchi, C.

    2012-10-01

    Life cycle assessment (LCA) is recognized as a useful analytical approach for quantifying environmental impacts of renewable energy technologies, including concentrating solar power (CSP). An LCA accounts for impacts from all stages in the development, operation, and decommissioning of a CSP plant, including such upstream stages as the extraction of raw materials used in system components, manufacturing of those components, and construction of the plant. The National Renewable Energy Laboratory is conducting a series of LCA studies for various CSP technologies. This paper contributes to a thorough LCA of a 100 MWnet molten salt power tower CSP plant by estimating the environmental impacts resulting from the manufacture of heliostats. Three life cycle metrics are evaluated: greenhouse gas emissions, water consumption, and cumulative energy demand. The heliostat under consideration (the 148 m2 Advanced Thermal Systems heliostat) emits 5,300 kg CO2eq, consumes 274 m3 of water, and requires 159,000 MJeq during its manufacture. Future work will incorporate the results from this study into the LCA model used to estimate the life cycle impacts of the entire 100 MWnet power tower CSP plant.

  18. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

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

    Archer, D.

    2015-05-21

    A two-dimensional model of a sediment column, with Darcy fluid flow, biological and thermal methane production, and permafrost and methane hydrate formation, is subjected to glacial–interglacial cycles in sea level, alternately exposing the continental shelf to the cold atmosphere during glacial times and immersing it in the ocean in interglacial times. The glacial cycles are followed by a "long-tail" 100 kyr warming due to fossil fuel combustion. The salinity of the sediment column in the interior of the shelf can be decreased by hydrological forcing to depths well below sea level when the sediment is exposed to the atmosphere. Theremore » is no analogous advective seawater-injecting mechanism upon resubmergence, only slower diffusive mechanisms. This hydrological ratchet is consistent with the existence of freshwater beneath the sea floor on continental shelves around the world, left over from the last glacial period. The salt content of the sediment column affects the relative proportions of the solid and fluid H2O-containing phases, but in the permafrost zone the salinity in the pore fluid brine is a function of temperature only, controlled by equilibrium with ice. Ice can tolerate a higher salinity in the pore fluid than methane hydrate can at low pressure and temperature, excluding methane hydrate from thermodynamic stability in the permafrost zone. The implication is that any methane hydrate existing today will be insulated from anthropogenic climate change by hundreds of meters of sediment, resulting in a response time of thousands of years. The strongest impact of the glacial–interglacial cycles on the atmospheric methane flux is due to bubbles dissolving in the ocean when sea level is high. When sea level is low and the sediment surface is exposed to the atmosphere, the atmospheric flux is sensitive to whether permafrost inhibits bubble migration in the model. If it does, the atmospheric flux is highest during the glaciating, sea level regression

  19. Moisture Flux Convergence in Regional and Global Climate Models: Implications for Droughts in the Southwestern United States Under Climate Change

    SciTech Connect (OSTI)

    Gao, Yanhong; Leung, Lai-Yung R.; Salathe, E.; Dominguez, Francina; Nijssen, Bart; Lettenmaier, D. P.

    2012-05-10

    The water cycle of the southwestern United States (SW) is dominated by winter storms that maintain a positive annual net precipitation. Analysis of the control and future climate from four pairs of regional and global climate models (RCMs and GCMs) shows that the RCMs simulate a higher fraction of transient eddy moisture fluxes because the hydrodynamic instabilities associated with flow over complex terrain are better resolved. Under global warming, this enables the RCMs to capture the response of transient eddies to increased atmospheric stability that allows more moisture to converge on the windward side of the mountains by blocking. As a result, RCMs simulate enhanced transient eddy moisture convergence in the SW compared to GCMs, although both robustly simulate drying due to enhanced moisture divergence by the divergent mean flow in a warmer climate. This enhanced convergence leads to reduced susceptibility to hydrological change in the RCMs compared to GCMs.

  20. Model predictive control system and method for integrated gasification combined cycle power generation

    DOE Patents [OSTI]

    Kumar, Aditya; Shi, Ruijie; Kumar, Rajeeva; Dokucu, Mustafa

    2013-04-09

    Control system and method for controlling an integrated gasification combined cycle (IGCC) plant are provided. The system may include a controller coupled to a dynamic model of the plant to process a prediction of plant performance and determine a control strategy for the IGCC plant over a time horizon subject to plant constraints. The control strategy may include control functionality to meet a tracking objective and control functionality to meet an optimization objective. The control strategy may be configured to prioritize the tracking objective over the optimization objective based on a coordinate transformation, such as an orthogonal or quasi-orthogonal projection. A plurality of plant control knobs may be set in accordance with the control strategy to generate a sequence of coordinated multivariable control inputs to meet the tracking objective and the optimization objective subject to the prioritization resulting from the coordinate transformation.

  1. Computational Model of Population Dynamics Based on the Cell Cycle and Local Interactions

    SciTech Connect (OSTI)

    Oprisan, Sorinel Adrian; Oprisan, Ana

    2005-03-31

    Our study bridges cellular (mesoscopic) level interactions and global population (macroscopic) dynamics of carcinoma. The morphological differences and transitions between well and smooth defined benign tumors and tentacular malignat tumors suggest a theoretical analysis of tumor invasion based on the development of mathematical models exhibiting bifurcations of spatial patterns in the density of tumor cells. Our computational model views the most representative and clinically relevant features of oncogenesis as a fight between two distinct sub-systems: the immune system of the host and the neoplastic system. We implemented the neoplastic sub-system using a three-stage cell cycle: active, dormant, and necrosis. The second considered sub-system consists of cytotoxic active (effector) cells -- EC, with a very broad phenotype ranging from NK cells to CTL cells, macrophages, etc. Based on extensive numerical simulations, we correlated the fractal dimensions for carcinoma, which could be obtained from tumor imaging, with the malignat stage. Our computational model was able to also simulate the effects of surgical, chemotherapeutical, and radiotherapeutical treatments.

  2. Identification of fuel cycle simulator functionalities for analysis of transition to a new fuel cycle

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

    Brown, Nicholas R.; Carlsen, Brett W.; Dixon, Brent W.; Feng, Bo; Greenberg, Harris R.; Hays, Ross D.; Passerini, Stefano; Todosow, Michael; Worrall, Andrew

    2016-06-09

    Dynamic fuel cycle simulation tools are intended to model holistic transient nuclear fuel cycle scenarios. As with all simulation tools, fuel cycle simulators require verification through unit tests, benchmark cases, and integral tests. Model validation is a vital aspect as well. Although compara-tive studies have been performed, there is no comprehensive unit test and benchmark library for fuel cycle simulator tools. The objective of this paper is to identify the must test functionalities of a fuel cycle simulator tool within the context of specific problems of interest to the Fuel Cycle Options Campaign within the U.S. Department of Energy smore » Office of Nuclear Energy. The approach in this paper identifies the features needed to cover the range of promising fuel cycle options identified in the DOE-NE Fuel Cycle Evaluation and Screening (E&S) and categorizes these features to facilitate prioritization. Features were categorized as essential functions, integrating features, and exemplary capabilities. One objective of this paper is to propose a library of unit tests applicable to each of the essential functions. Another underlying motivation for this paper is to encourage an international dialog on the functionalities and standard test methods for fuel cycle simulator tools.« less

  3. Update 1 to: A Dispersion Modeling Analysis of Downwash from Mirant's

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

    Potomac River Power Plant, Modeling Unit 1 Emissions in a Cycling Mode | Department of Energy 1 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Unit 1 Emissions in a Cycling Mode Update 1 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Unit 1 Emissions in a Cycling Mode Docket No. EO-05-01. This report describes dispersion modeling performed for Unit 1 at Mirant's Potomac River Generating

  4. The watershed-scale optimized and rearranged landscape design (WORLD) model and local biomass processing depots for sustainable biofuel production: Integrated life cycle assessments

    SciTech Connect (OSTI)

    Eranki, Pragnya L.; Manowitz, David H.; Bals, Bryan D.; Izaurralde, Roberto C.; Kim, Seungdo; Dale, Bruce E.

    2013-07-23

    An array of feedstock is being evaluated as potential raw material for cellulosic biofuel production. Thorough assessments are required in regional landscape settings before these feedstocks can be cultivated and sustainable management practices can be implemented. On the processing side, a potential solution to the logistical challenges of large biorefi neries is provided by a network of distributed processing facilities called local biomass processing depots. A large-scale cellulosic ethanol industry is likely to emerge soon in the United States. We have the opportunity to influence the sustainability of this emerging industry. The watershed-scale optimized and rearranged landscape design (WORLD) model estimates land allocations for different cellulosic feedstocks at biorefinery scale without displacing current animal nutrition requirements. This model also incorporates a network of the aforementioned depots. An integrated life cycle assessment is then conducted over the unified system of optimized feedstock production, processing, and associated transport operations to evaluate net energy yields (NEYs) and environmental impacts.

  5. GREET Model Expanded to Better Address Biofuel Life-Cycle Analysis...

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

    modules; an update of combustion equipment emission factors; and new data on land management change effects on stover-derived biofuel life-cycle greenhouse gas emissions. ...

  6. A Finite Element Model Of Self-Resonating Bimorph Microcantilever For Fast Temperature Cycling In A Pyroelectric Energy Harvester

    SciTech Connect (OSTI)

    Mostafa, Salwa; Lavrik, Nickolay V; Bannuru, Thirumalesh; Rajic, Slobodan; Islam, Syed K; Datskos, Panos G; Hunter, Scott Robert

    2011-01-01

    A self resonating bimorph cantilever structure for fast temperature cycling in a pyroelectric energy harvester has been modeled using a finite element method. The effect of constituting material properties and system parameters on the frequency and magnitude of temperature cycling and the efficiency of energy recycling using the proposed structure has been investigated. Results show that thermal contact conductance and heat source temperature play a key role in dominating the cycling frequency and efficiency of energy recycling. An optimal solution for the most efficient energy scavenging process has been sought by studying the performance trend with different variable parameters such as thermal contact conductance, heat source temperature, device aspect ratio and constituent materials of varying thermal conductivity and expansion coefficients.

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

    SciTech Connect (OSTI)

    NSTec Geotechnical Sciences Group

    2007-03-01

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

  8. Glass Composition Constraint Recommendations for Use in Life-Cycle Mission Modeling

    SciTech Connect (OSTI)

    McCloy, John S.; Vienna, John D.

    2010-05-03

    The component concentration limits that most influence the predicted Hanford life-cycle HLW glass volume by HTWOS were re-evaluated. It was assumed that additional research and development work in glass formulation and melter testing would be performed to improve the understanding of component effects on the processability and product quality of these HLW glasses. Recommendations were made to better estimate the potential component concentration limits that could be applied today while technology development is underway to best estimate the volume of HLW glass that will eventually be produced at Hanford. The limits for concentrations of P2O5, Bi2O3, and SO3 were evaluated along with the constraint used to avoid nepheline formation in glass. Recommended concentration limits were made based on the current HLW glass property models being used by HTWOS (Vienna et al. 2009). These revised limits are: 1) The current ND should be augmented by the OB limit of OB ≤ 0.575 so that either the normalized silica (NSi) is less that the 62% limit or the OB is below the 0.575 limit. 2) The mass fraction of P2O5 limit should be revised to allow for up to 4.5 wt%, depending on CaO concentrations. 3) A Bi2O3 concentration limit of 7 wt% should be used. 4) The salt accumulation limit of 0.5 wt% SO3 may be increased to 0.6 wt%. Again, these revised limits do not obviate the need for further testing, but make it possible to more accurately predict the impact of that testing on ultimate HLW glass volumes.

  9. World nuclear fuel cycle requirements 1991

    SciTech Connect (OSTI)

    Not Available

    1991-10-10

    The nuclear fuel cycle consists of mining and milling uranium ore, processing the uranium into a form suitable for generating electricity, burning'' the fuel in nuclear reactors, and managing the resulting spent nuclear fuel. This report presents projections of domestic and foreign requirements for natural uranium and enrichment services as well as projections of discharges of spent nuclear fuel. These fuel cycle requirements are based on the forecasts of future commercial nuclear power capacity and generation published in a recent Energy Information Administration (EIA) report. Also included in this report are projections of the amount of spent fuel discharged at the end of each fuel cycle for each nuclear generating unit in the United States. The International Nuclear Model is used for calculating the projected nuclear fuel cycle requirements. 14 figs., 38 tabs.

  10. Development and application of the EPIC model for carbon cycle, greenhouse-gas mitigation, and biofuel studies

    SciTech Connect (OSTI)

    Izaurralde, Roberto C.; Mcgill, William B.; Williams, J.R.

    2012-06-01

    This chapter provides a comprehensive review of the EPIC model in relation to carbon cycle, greenhouse-gas mitigation, and biofuel applications. From its original capabilities and purpose (i.e., quantify the impacts or erosion on soil productivity), the EPIC model has evolved into a comprehensive terrestrial ecosystem model for simulating with more or less process-level detail many ecosystem processes such as weather, hydrology, plant growth and development, carbon cycle (including erosion), nutrient cycling, greenhouse-gas emissions, and the most complete set of manipulations that can be implemented on a parcel of land (e.g. tillage, harvest, fertilization, irrigation, drainage, liming, burning, pesticide application). The chapter also provides details and examples of the latest efforts in model development such as the coupled carbon-nitrogen model, a microbial denitrification model with feedback to the carbon decomposition model, updates on calculation of ecosystem carbon balances, and carbon emissions from fossil fuels. The chapter has included examples of applications of the EPIC model in soil carbon sequestration, net ecosystem carbon balance, and biofuel studies. Finally, the chapter provides the reader with an update on upcoming improvements in EPIC such as the additions of modules for simulating biochar amendments, sorption of soluble C in subsoil horizons, nitrification including the release of N2O, and the formation and consumption of methane in soils. Completion of these model development activities will render an EPIC model with one of the most complete representation of biogeochemical processes and capable of simulating the dynamic feedback of soils to climate and management in terms not only of transient processes (e.g., soil water content, heterotrophic respiration, N2O emissions) but also of fundamental soil properties (e.g. soil depth, soil organic matter, soil bulk density, water limits).

  11. The Modeling of a Standalone Solid-Oxide Fuel Cell Auxiliary Power Unit

    SciTech Connect (OSTI)

    Lu, Ning; Li, Qinghe; Sun, Xin; Khaleel, Mohammad A.

    2006-10-27

    In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module; two heat exchanger modules; and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will benefit design engineers to adjust design parameters to optimize the performance. The modeling results of the heat-up stage of an SOFC APU and the output voltage response to a sudden load change are presented in the paper. The fuel flow regulation based on fuel utilization is also briefly discussed.

  12. The need for a characteristics-based approach to radioactive waste classification as informed by advanced nuclear fuel cycles using the fuel-cycle integration and tradeoffs (FIT) model

    SciTech Connect (OSTI)

    Djokic, D. [Department of Nuclear Engineering, University of California, Berkeley, 3115B Etcheverry Hall, Berkeley, CA 94720-1730 (United States); Piet, S.; Pincock, L.; Soelberg, N. [Idaho National Laboratory - INL, 2525 North Fremont Avenue, Idaho Falls, ID 83415 (United States)

    2013-07-01

    This study explores the impact of wastes generated from potential future fuel cycles and the issues presented by classifying these under current classification criteria, and discusses the possibility of a comprehensive and consistent characteristics-based classification framework based on new waste streams created from advanced fuel cycles. A static mass flow model, Fuel-Cycle Integration and Tradeoffs (FIT), was used to calculate the composition of waste streams resulting from different nuclear fuel cycle choices. Because heat generation is generally the most important factor limiting geological repository areal loading, this analysis focuses on the impact of waste form heat load on waste classification practices, although classifying by metrics of radiotoxicity, mass, and volume is also possible. Waste streams generated in different fuel cycles and their possible classification based on the current U.S. framework and international standards are discussed. It is shown that the effects of separating waste streams are neglected under a source-based radioactive waste classification system. (authors)

  13. Verification of Sulfate Attack Penetration Rates for Saltstone Disposal Unit Modeling

    SciTech Connect (OSTI)

    Flach, G. P.

    2015-05-12

    Recent Special Analysis modeling of Saltstone Disposal Units consider sulfate attack on concrete and utilize degradation rates estimated from Cementitious Barriers Partnership software simulations. This study provides an independent verification of those simulation results using an alternative analysis method and an independent characterization data source. The sulfate penetration depths estimated herein are similar to the best-estimate values in SRNL-STI-2013-00118 Rev. 2 and well below the nominal values subsequently used to define Saltstone Special Analysis base cases.

  14. Modeling and experimental results for condensing supercritical CO2 power cycles.

    SciTech Connect (OSTI)

    Wright, Steven Alan; Conboy, Thomas M.; Radel, Ross F.; Rochau, Gary Eugene

    2011-01-01

    This Sandia supported research project evaluated the potential improvement that 'condensing' supercritical carbon dioxide (S-CO{sub 2}) power cycles can have on the efficiency of Light Water Reactors (LWR). The analytical portion of research project identified that a S-CO{sub 2} 'condensing' re-compression power cycle with multiple stages of reheat can increase LWR power conversion efficiency from 33-34% to 37-39%. The experimental portion of the project used Sandia's S-CO{sub 2} research loop to show that the as designed radial compressor could 'pump' liquid CO{sub 2} and that the gas-cooler's could 'condense' CO{sub 2} even though both of these S-CO{sub 2} components were designed to operate on vapor phase S-CO{sub 2} near the critical point. There is potentially very high value to this research as it opens the possibility of increasing LWR power cycle efficiency, above the 33-34% range, while lowering the capital cost of the power plant because of the small size of the S-CO{sub 2} power system. In addition it provides a way to incrementally build advanced LWRs that are optimally designed to couple to S-CO{sub 2} power conversion systems to increase the power cycle efficiency to near 40%.

  15. Simulating the Impacts of Disturbances on Forest Carbon Cycling in North America: Processes, Data, Models, and Challenges

    SciTech Connect (OSTI)

    Liu, Shuguang; Bond-Lamberty, Benjamin; Hicke, J.; Vargas, Rodrigo; Zhao, Shuqing; Chen, Jing Ming; Edburg, Steve; Hu, Yueming; Liu, Jinxun; McGuire, A. David; Xiao, Jingfeng; Keane, Robert; Yuan, Wenping; Tang, Jianwu; Luo, Yiqi; Potter, Christopher; Oeding, Jennifer

    2011-11-08

    Disturbances disrupt the forest structures and alter forest resources, substrate availability, or the physical environment. Understanding disturbances and their impacts is critical for a better quantification of North American carbon dynamics. We reviewed the status and major challenges in simulating the impacts of disturbances on forest carbon cycling in North America from the perspectives of process understanding, disturbance characterization, and modeling, and found some major issues. First, we do not have adequate continentally-consistent disturbance databases to support the NACP missions. Community effort, in collaborating with the modeling community, should be designated to systematically define international standards for disturbance databases with explicit inclusion of uncertainty measurements, adequate spatial and temporal resolutions, and explicit and quantifiable linkages with model simulations. Second, there is a need to develop effective and comprehensive process-based procedures or algorithms that can be used to quantify the immediate and long-term impacts of disturbances on forest succession, soils, microclimate, and cycles of carbon, water, and nutrients. These algorithms should be evaluated not only on the carbon cycle but also on the simulations of vegetation succession, alterations of soil and microclimate, and water and nutrients dynamics because adequate simulations of carbon dynamics rely on the correct quantification of the changes of soil and vegetation conditions. Third, the scaling challenges have rarely been addressed at the continental scale. We do not understand which processes and properties at a given temporal or spatial scales are critical while others can be simplified when we try to balance the North American carbon budget. Previous and current model simulations at the continental scale did not incorporate a full suite of disturbances information (because they do not exist as described above), and therefore provided little insight

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

    SciTech Connect (OSTI)

    Geotechnical Sciences Group Bechtel Nevada

    2006-01-01

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

  17. Update 3 to: A Dispersion Modeling Analysis of Downwash from Mirant's Potomac River Power Plant, Modeling Units 1 and 4 Together

    Broader source: Energy.gov [DOE]

    Docket No. EO-05-01. Docket No. EO-05-01. This report describes dispersion modeling performed for Units 1 and 4 at Mirant's Potomac River Generating Station. The purpose of the modeling was to...

  18. Ocean Carbon Cycle Models from the Carbon Dioxide Information Analysis Center (CDIAC)

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

    \tPacific data-model intercomparison from Patrick Wetzel (Max Planck Institute for Meteorology, Germany)

  19. Direct-contact condensers for open-cycle OTEC applications: Model validation with fresh water experiments for structured packings

    SciTech Connect (OSTI)

    Bharathan, D.; Parsons, B.K.; Althof, J.A.

    1988-10-01

    The objective of the reported work was to develop analytical methods for evaluating the design and performance of advanced high-performance heat exchangers for use in open-cycle thermal energy conversion (OC-OTEC) systems. This report describes the progress made on validating a one-dimensional, steady-state analytical computer of fresh water experiments. The condenser model represents the state of the art in direct-contact heat exchange for condensation for OC-OTEC applications. This is expected to provide a basis for optimizing OC-OTEC plant configurations. Using the model, we examined two condenser geometries, a cocurrent and a countercurrent configuration. This report provides detailed validation results for important condenser parameters for cocurrent and countercurrent flows. Based on the comparisons and uncertainty overlap between the experimental data and predictions, the model is shown to predict critical condenser performance parameters with an uncertainty acceptable for general engineering design and performance evaluations. 33 refs., 69 figs., 38 tabs.

  20. Structural analysis of three global land models on carbon cycle simulations using a traceability framework

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

    Rafique, R.; Xia, J.; Hararuk, O.; Luo, Y.

    2014-06-27

    Modeled carbon (C) storage capacity is largely determined by the C residence time and net primary productivity (NPP). Extensive research has been done on NPP dynamics but the residence time and their relationships with C storage are much less studied. In this study, we implemented a traceability analysis to understand the modeled C storage and residence time in three land surface models: CSIRO's Atmosphere Biosphere Land Exchange (CABLE) with 9 C pools, Community Land Model (version 3.5) combined with Carnegie-Ames-Stanford Approach (CLM3.5-CASA) with 12 C pools and Community Land Model (version 4) (CLM4) with 26 C pools. The globally averagedmoreC storage and residence time was computed at both individual pool and total ecosystem levels. The spatial distribution of total ecosystem C storage and residence time differ greatly among the three models. The CABLE model showed a closer agreement with measured C storage and residence time in plant and soil pools than CLM3.5-CASA and CLM4. However, CLM3.5-CASA and CLM4 were close to each other in modeled C storage but not with measured data. CABLE stores more C in root whereas CLM3.5-CASA and CLM4 store more C in woody pools, partly due to differential NPP allocation in respective pools. The C residence time in individual C pools is greatly different among models, largely because of different transfer coefficient values among pools. CABLE had higher bulk residence time for soil C pools than the other two models. Overall, the traceability analysis used in this study can help fully characterizes the behavior of complex land models.less

  1. Use of a dynamic simulation model to understand nitrogen cycling in the middle Rio Grande, NM.

    SciTech Connect (OSTI)

    Meixner, Tom; Tidwell, Vincent Carroll; Oelsner, Gretchen; Brooks, Paul; Roach, Jesse D.

    2008-08-01

    Water quality often limits the potential uses of scarce water resources in semiarid and arid regions. To best manage water quality one must understand the sources and sinks of both solutes and water to the river system. Nutrient concentration patterns can identify source and sink locations, but cannot always determine biotic processes that affect nutrient concentrations. Modeling tools can provide insight into these large-scale processes. To address questions about large-scale nitrogen removal in the Middle Rio Grande, NM, we created a system dynamics nitrate model using an existing integrated surface water--groundwater model of the region to evaluate our conceptual models of uptake and denitrification as potential nitrate removal mechanisms. We modeled denitrification in groundwater as a first-order process dependent only on concentration and used a 5% denitrification rate. Uptake was assumed to be proportional to transpiration and was modeled as a percentage of the evapotranspiration calculated within the model multiplied by the nitrate concentration in the water being transpired. We modeled riparian uptake as 90% and agricultural uptake as 50% of the respective evapotranspiration rates. Using these removal rates, our model results suggest that riparian uptake, agricultural uptake and denitrification in groundwater are all needed to produce the observed nitrate concentrations in the groundwater, conveyance channels, and river as well as the seasonal concentration patterns. The model results indicate that a total of 497 metric tons of nitrate-N are removed from the Middle Rio Grande annually. Where river nitrate concentrations are low and there are no large nitrate sources, nitrate behaves nearly conservatively and riparian and agricultural uptake are the most important removal mechanisms. Downstream of a large wastewater nitrate source, denitrification and agricultural uptake were responsible for approximately 90% of the nitrogen removal.

  2. Fuel-Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model

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

    Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model Michael Wang Argonne National Laboratory June 10, 2008 Project ID # AN2 This presentation does not contain any proprietary, confidential, or otherwise restricted information 2 Overview * Project start date: Oct. 2002 * Project end date: Continuous * Percent complete: N/A * Inconsistent data, assumptions, and guidelines * Suite of models and tools * Unplanned studies and analyses * Total project funding from DOE: $2.04 million

  3. Accelerating the spin-up of the coupled carbon and nitrogen cycle model in CLM4

    SciTech Connect (OSTI)

    Fang, Yilin; Liu, Chongxuan; Leung, Lai-Yung R.

    2015-03-24

    The commonly adopted biogeochemistry spin-up process in an Earth system model (ESM) is to run the model for hundreds to thousands of years subject to periodic atmospheric forcing to reach dynamic steady state of the carbon–nitrogen (CN) models. A variety of approaches have been proposed to reduce the computation time of the spin-up process. Significant improvement in computational efficiency has been made recently. However, a long simulation time is still required to reach the common convergence criteria of the coupled carbon–nitrogen model. A gradient projection method was proposed and used to further reduce the computation time after examining the trend of the dominant carbon pools. The Community Land Model version 4 (CLM4) with a carbon and nitrogen component was used in this study. From point-scale simulations, we found that the method can reduce the computation time by 20–69% compared to one of the fastest approaches in the literature. We also found that the cyclic stability of total carbon for some cases differs from that of the periodic atmospheric forcing, and some cases even showed instability. Close examination showed that one case has a carbon periodicity much longer than that of the atmospheric forcing due to the annual fire disturbance that is longer than half a year. The rest was caused by the instability of water table calculation in the hydrology model of CLM4. The instability issue is resolved after we replaced the hydrology scheme in CLM4 with a flow model for variably saturated porous media.

  4. Accelerating the spin-up of the coupled carbon and nitrogen cycle model in CLM4

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

    Fang, Yilin; Liu, Chongxuan; Leung, Lai-Yung R.

    2015-03-24

    The commonly adopted biogeochemistry spin-up process in an Earth system model (ESM) is to run the model for hundreds to thousands of years subject to periodic atmospheric forcing to reach dynamic steady state of the carbon–nitrogen (CN) models. A variety of approaches have been proposed to reduce the computation time of the spin-up process. Significant improvement in computational efficiency has been made recently. However, a long simulation time is still required to reach the common convergence criteria of the coupled carbon–nitrogen model. A gradient projection method was proposed and used to further reduce the computation time after examining the trendmore » of the dominant carbon pools. The Community Land Model version 4 (CLM4) with a carbon and nitrogen component was used in this study. From point-scale simulations, we found that the method can reduce the computation time by 20–69% compared to one of the fastest approaches in the literature. We also found that the cyclic stability of total carbon for some cases differs from that of the periodic atmospheric forcing, and some cases even showed instability. Close examination showed that one case has a carbon periodicity much longer than that of the atmospheric forcing due to the annual fire disturbance that is longer than half a year. The rest was caused by the instability of water table calculation in the hydrology model of CLM4. The instability issue is resolved after we replaced the hydrology scheme in CLM4 with a flow model for variably saturated porous media.« less

  5. Thermodynamic constitutive model for load-biased thermal cycling test of shape memory alloy

    SciTech Connect (OSTI)

    Young, Sung; Nam, Tae-Hyun

    2013-12-15

    Graphical abstract: - Highlights: Thermodynamic calculation model for martensitic transformation of shape memory alloy was proposed. Evolution of the self-accommodation was considered independently by a rate-dependent kinetic equation. Finite element calculation was conducted for B2B19? transformation of Ti44.5Ni5Cu0.5 V (at.%). Three-dimensional numerical results predict the macroscopic strain under bias loading accurately. - Abstract: This paper presents a three-dimensional calculation model for martensitic phase transformation of shape memory alloy. Constitutive model based on thermodynamic theory was provided. The average behavior was accounted for by considering the volume fraction of each martensitic variant in the material. Evolution of the volume fraction of each variant was determined by a rate-dependent kinetic equation. We assumed that nucleation rate is faster for the self-accommodation than for the stress-induced variants. Three-dimensional finite element analysis was conducted and the results were compared with the experimental data of Ti44.5Ni5Cu0.5 V (at.%) alloy under bias loading.

  6. Regional climate effects of irrigation and urbanization in thewestern united states: a model intercomparison

    SciTech Connect (OSTI)

    Snyder, M.A.; Kueppers, L.M.; Sloan, L.C.; Cavan, D.C.; Jin, J.; Kanamaru, H.; Miller, N.L.; Tyree, M.; Du, H.; Weare, B.

    2006-05-01

    In the western United States, more than 30,500 square miles has been converted to irrigated agriculture and urban areas. This study compares the climate responses of four regional climate models (RCMs) to these past land-use changes. The RCMs used two contrasting land cover distributions: potential natural vegetation, and modern land cover that includes agriculture and urban areas. Three of the RCMs represented irrigation by supplementing soil moisture, producing large decreases in August mean (-2.5 F to -5.6 F) and maximum (-5.2 F to -10.1 F) 2-meter temperatures where natural vegetation was converted to irrigated agriculture. Conversion to irrigated agriculture also resulted in large increases in relative humidity (9 percent 36 percent absolute change). Only one of the RCMs produced increases in summer minimum temperature. Converting natural vegetation to urban land cover produced modest but discernable climate effects in all models, with the magnitude of the effects dependent upon the preexisting vegetation type. Overall, the RCM results indicate that land use change impacts are most pronounced during the summer months, when surface heating is strongest and differences in surface moisture between irrigated land and natural vegetation are largest. The irrigation effect on summer maximum temperatures is comparable in magnitude (but opposite in sign) to predicted future temperature change due to increasing greenhouse gas concentrations.

  7. Completion Report for Model Evaluation Well ER-11-2: Corrective Action Unit 98: Frenchman Flat

    SciTech Connect (OSTI)

    NSTec Underground Test Area and Boreholes Programs and Operations

    2013-01-22

    Model Evaluation Well ER-11-2 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of Nevada Environmental Management Operations at the Nevada National Security Site (formerly known as the Nevada Test Site). The well was drilled in August 2012 as part of a model evaluation program in the Frenchman Flat area of Nye County, Nevada. The primary purpose of the well was to provide detailed geologic, hydrogeologic, chemical, and radionuclide data that can be used to test and build confidence in the applicability of the Frenchman Flat Corrective Action Unit flow and transport models for their intended purpose. In particular, this well was designed to provide data to evaluate the uncertainty in model forecasts of contaminant migration from the upgradient underground nuclear test PIN STRIPE, conducted in borehole U-11b in 1966. Well ER-11-2 will provide information that can be used to refine the Phase II Frenchman Flat hydrostratigraphic framework model if necessary, as well as to support future groundwater flow and transport modeling. The main 31.1-centimeter (cm) hole was drilled to a total depth of 399.6 meters (m). A completion casing string was not set in Well ER-11-2. However, a piezometer string was installed in the 31.1-cm open hole. The piezometer is composed of 7.3-cm stainless-steel tubing hung on 6.0-cm carbon-steel tubing via a crossover sub. The piezometer string was landed at 394.5 m, for monitoring the lower tuff confining unit. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 m, various geophysical logs, water quality (including tritium and other test-related radionuclides) measurements, and water level measurements. The well penetrated 42.7 m of Quaternary and Tertiary alluvium and 356.9 m of Tertiary volcanic rock. The water-level measured in the piezometer string on September 25, 2012, was 353.8 m below ground surface. No

  8. The United States of America and the People`s Republic of China experts report on integrated gasification combined-cycle technology (IGCC)

    SciTech Connect (OSTI)

    1996-12-01

    A report written by the leading US and Chinese experts in Integrated Gasification Combined Cycle (IGCC) power plants, intended for high level decision makers, may greatly accelerate the development of an IGCC demonstration project in the People`s Republic of China (PRC). The potential market for IGCC systems in China and the competitiveness of IGCC technology with other clean coal options for China have been analyzed in the report. Such information will be useful not only to the Chinese government but also to US vendors and companies. The goal of this report is to analyze the energy supply structure of China, China`s energy and environmental protection demand, and the potential market in China in order to make a justified and reasonable assessment on feasibility of the transfer of US Clean Coal Technologies to China. The Expert Report was developed and written by the joint US/PRC IGCC experts and will be presented to the State Planning Commission (SPC) by the President of the CAS to ensure consideration of the importance of IGCC for future PRC power production.

  9. Federal Register Notice for Life Cycle Greenhouse Gas Perspective...

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

    Life Cycle Greenhouse Gas Perspective on Exporting Liquefied Natural Gas from the United States Federal Register Notice for Life Cycle Greenhouse Gas Perspective on Exporting Liquefied ...

  10. Combining Turbine Blade-Strike and Life Cycle Models to Assess Mitigation Strategies for Fish Passing Dams

    SciTech Connect (OSTI)

    Ferguson, John W.; Ploskey, Gene R.; Leonardsson, Kjell; Zabel, Richard W.; Lundqvist, Hans

    2008-08-01

    Combining the two models produced a rapid, cost effective tool for assessing dam passage impacts to fish populations and prioritizing among mitigation strategies for conserving fish stocks in regulated rivers. Estimated mortality of juvenile and adult Atlantic salmon (Salmo salar) and sea trout (S. trutta) passing turbines at two dams in northern Sweden was significantly higher for Kaplan turbines compared to Francis turbines, and for adult fish compared to juveniles based on blade strike models. Mean probability of mortality ranged from 6.7% for salmon smolts passing Francis turbines to >100% for adult salmon passing Kaplan turbines. Life cycle modeling allowed benefits to be assessed for three alternatives that mitigated this mortality. Salmon population responses varied considerably among alternatives and rivers: growth rates improved as much as 17.9%, female escapements increased up to 669%, and more than 1,300 additional female salmon were produced in one case. Protecting both smolts and adults provided benefits, and in one river, mitigating turbine mortality alone was estimated to have met the production capacity of the available habitat.

  11. MELCOR Model of the Spent Fuel Pool of Fukushima Dai-ichi Unit 4

    SciTech Connect (OSTI)

    Carbajo, Juan J

    2012-01-01

    Unit 4 of the Fukushima Dai-ichi Nuclear Power Plant suffered a hydrogen explosion at 6:00 am on March 15, 2011, exactly 3.64 days after the earthquake hit the plant and the off-site power was lost. The earthquake occurred on March 11 at 2:47 pm. Since the reactor of this Unit 4 was defueled on November 29, 2010, and all its fuel was stored in the spent fuel pool (SFP4), it was first believed that the explosion was caused by hydrogen generated by the spent fuel, in particular, by the recently discharged core. The hypothetical scenario was: power was lost, cooling to the SFP4 water was lost, pool water heated/boiled, water level decreased, fuel was uncovered, hot Zircaloy reacted with steam, hydrogen was generated and accumulated above the pool, and the explosion occurred. Recent analyses of the radioisotopes present in the water of the SFP4 and underwater video indicated that this scenario did not occur - the fuel in this pool was not damaged and was never uncovered the hydrogen of the explosion was apparently generated in Unit 3 and transported through exhaust ducts that shared the same chimney with Unit 4. This paper will try to answer the following questions: Could that hypothetical scenario in the SFP4 had occurred? Could the spent fuel in the SPF4 generate enough hydrogen to produce the explosion that occurred 3.64 days after the earthquake? Given the magnitude of the explosion, it was estimated that at least 150 kg of hydrogen had to be generated. As part of the investigations of this accident, MELCOR models of the SFP4 were prepared and a series of calculations were completed. The latest version of MELCOR, version 2.1 (Ref. 1), was employed in these calculations. The spent fuel pool option for BWR fuel was selected in MELCOR. The MELCOR model of the SFP4 consists of a total of 1535 fuel assemblies out of which 548 assemblies are from the core defueled on Nov. 29, 2010, 783 assemblies are older assemblies, and 204 are new/fresh assemblies. The total decay

  12. Completion Report for Model Evaluation Well ER-5-5: Corrective Action Unit 98: Frenchman Flat

    SciTech Connect (OSTI)

    NSTec Underground Test Area and Boreholes Programs and Operations

    2013-01-18

    Model Evaluation Well ER-5-5 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of Nevada Environmental Management Operations at the Nevada National Security Site (formerly known as the Nevada Test Site). The well was drilled in July and August 2012 as part of a model evaluation well program in the Frenchman Flat area of Nye County, Nevada. The primary purpose of the well was to provide detailed geologic, hydrogeologic, chemical, and radiological data that can be used to test and build confidence in the applicability of the Frenchman Flat Corrective Action Unit flow and transport models for their intended purpose. In particular, this well was designed to obtain data to evaluate the uncertainty in model forecasts of contaminant migration from the upgradient underground nuclear test MILK SHAKE, conducted in Emplacement Hole U-5k in 1968, which were considered to be uncertain due to the unknown extent of a basalt lava-flow aquifer present in this area. Well ER-5-5 is expected to provide information to refine the Phase II Frenchman Flat hydrostratigraphic framework model, if necessary, as well as to support future groundwater flow and transport modeling. The 31.1-centimeter (cm) diameter hole was drilled to a total depth of 331.3 meters (m). The completion string, set at the depth of 317.2 m, consists of 16.8-cm stainless-steel casing hanging from 19.4-cm carbon-steel casing. The 16.8-cm stainless-steel casing has one slotted interval open to the basalt lava-flow aquifer and limited intervals of the overlying and underlying alluvial aquifer. A piezometer string was also installed in the annulus between the completion string and the borehole wall. The piezometer is composed of 7.3-cm stainless-steel tubing suspended from 6.0-cm carbon-steel tubing. The piezometer string was landed at 319.2 m, to monitor the basalt lava-flow aquifer. Data collected during and shortly after hole construction include

  13. Evaluation of global horizontal irradiance to plane-of-array irradiance models at locations across the United States

    SciTech Connect (OSTI)

    Lave, Matthew; Hayes, William; Pohl, Andrew; Hansen, Clifford W.

    2015-02-02

    We report an evaluation of the accuracy of combinations of models that estimate plane-of-array (POA) irradiance from measured global horizontal irradiance (GHI). This estimation involves two steps: 1) decomposition of GHI into direct and diffuse horizontal components and 2) transposition of direct and diffuse horizontal irradiance (DHI) to POA irradiance. Measured GHI and coincident measured POA irradiance from a variety of climates within the United States were used to evaluate combinations of decomposition and transposition models. A few locations also had DHI measurements, allowing for decoupled analysis of either the decomposition or the transposition models alone. Results suggest that decomposition models had mean bias differences (modeled versus measured) that vary with climate. Transposition model mean bias differences depended more on the model than the location. Lastly, when only GHI measurements were available and combinations of decomposition and transposition models were considered, the smallest mean bias differences were typically found for combinations which included the Hay/Davies transposition model.

  14. Financing Strategies for Nuclear Fuel Cycle Facility

    SciTech Connect (OSTI)

    David Shropshire; Sharon Chandler

    2005-12-01

    To help meet our nation’s energy needs, reprocessing of spent nuclear fuel is being considered more and more as a necessary step in a future nuclear fuel cycle, but incorporating this step into the fuel cycle will require considerable investment. This report presents an evaluation of financing scenarios for reprocessing facilities integrated into the nuclear fuel cycle. A range of options, from fully government owned to fully private owned, was evaluated using a DPL (Dynamic Programming Language) 6.0 model, which can systematically optimize outcomes based on user-defined criteria (e.g., lowest life-cycle cost, lowest unit cost). Though all business decisions follow similar logic with regard to financing, reprocessing facilities are an exception due to the range of financing options available. The evaluation concludes that lowest unit costs and lifetime costs follow a fully government-owned financing strategy, due to government forgiveness of debt as sunk costs. Other financing arrangements, however, including regulated utility ownership and a hybrid ownership scheme, led to acceptable costs, below the Nuclear Energy Agency published estimates. Overwhelmingly, uncertainty in annual capacity led to the greatest fluctuations in unit costs necessary for recovery of operating and capital expenditures; the ability to determine annual capacity will be a driving factor in setting unit costs. For private ventures, the costs of capital, especially equity interest rates, dominate the balance sheet; the annual operating costs dominate the government case. It is concluded that to finance the construction and operation of such a facility without government ownership could be feasible with measures taken to mitigate risk, and that factors besides unit costs should be considered (e.g., legal issues, social effects, proliferation concerns) before making a decision on financing strategy.

  15. Ocean acidification over the next three centuries using a simple global climate carbon-cycle model: projections and sensitivities

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

    Hartin, Corinne A.; Bond-Lamberty, Benjamin; Patel, Pralit; Mundra, Anupriya

    2016-08-01

    Continued oceanic uptake of anthropogenic CO2 is projected to significantly alter the chemistry of the upper oceans over the next three centuries, with potentially serious consequences for marine ecosystems. Relatively few models have the capability to make projections of ocean acidification, limiting our ability to assess the impacts and probabilities of ocean changes. In this study we examine the ability of Hector v1.1, a reduced-form global model, to project changes in the upper ocean carbonate system over the next three centuries, and quantify the model's sensitivity to parametric inputs. Hector is run under prescribed emission pathways from the Representative Concentrationmore » Pathways (RCPs) and compared to both observations and a suite of Coupled Model Intercomparison (CMIP5) model outputs. Current observations confirm that ocean acidification is already taking place, and CMIP5 models project significant changes occurring to 2300. Hector is consistent with the observational record within both the high- (> 55°) and low-latitude oceans (< 55°). The model projects low-latitude surface ocean pH to decrease from preindustrial levels of 8.17 to 7.77 in 2100, and to 7.50 in 2300; aragonite saturation levels (ΩAr) decrease from 4.1 units to 2.2 in 2100 and 1.4 in 2300 under RCP 8.5. These magnitudes and trends of ocean acidification within Hector are largely consistent with the CMIP5 model outputs, although we identify some small biases within Hector's carbonate system. Of the parameters tested, changes in [H+] are most sensitive to parameters that directly affect atmospheric CO2 concentrations – Q10 (terrestrial respiration temperature response) as well as changes in ocean circulation, while changes in ΩAr saturation levels are sensitive to changes in ocean salinity and Q10. We conclude that Hector is a robust tool well suited for rapid ocean acidification projections and sensitivity analyses, and it is capable of emulating both current observations

  16. Associative list processing unit

    DOE Patents [OSTI]

    Hemmert, Karl Scott; Underwood, Keith D

    2014-04-01

    An associative list processing unit and method comprising employing a plurality of prioritized cell blocks and permitting inserts to occur in a single clock cycle if all of the cell blocks are not full.

  17. Development and Integration of Genome-Enabled Techniques to Track and Predict the Cycling of Carbon in Model Microbial Communities

    SciTech Connect (OSTI)

    Banfield, Jillian

    2014-11-26

    The primary objective of this project was to establish widely applicable, high-throughput omics methods for tracking carbon flow in microbial communities at a strain-resolved molecular level. We developed and applied these methods to study a well-established microbial community model system with a long history of omics innovation: chemoautotrophic biofilms grown in an acid mine drainage (AMD) environment. The methods are now being transitioned (in a new project) to study soil. Using metagenomics, stable-isotope proteomics, stable-isotope metabolomics, transcriptomics, and microscopy, we tracked carbon flow during initial biofilm growth involving CO2 fixation, through the maturing biofilm community consisting of multiple trophic levels, and during an anaerobic degradative phase after biofilms sink. This work included explicit consideration of the often overlooked roles of archaea and microbial eukaryotes (fungi) in carbon turnover. We also analyzed where the eosystem begins to fail in response to thermal perturbation, and how perturbation propagates through a carbon cycle. We investigated the form of strain variation in microbial communities, the importance of strain variants, and the rate and form of strain evolution. Overall, the project generated an array of new, integrated omics approaches and provided unprecedented insight into the functioning of a natural ecosystem. This project supported graduate training for five Ph.D. students and three post doctoral fellows and contributed directly to at least 26 publications (two in Science).

  18. UGE Scheduler Cycle Time

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

    UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Daily Genepool Weekly Phoebe Cycle Time Phoebe Daily Phoebe Weekly What is the Scheduler Cycle? The...

  19. Life-Cycle Assessment of Energy and Environmental Impacts of...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; ENVIRONMENTAL IMPACTS; LIFE CYCLE; LIGHT BULBS; ...

  20. Developing Model Constraints on Northern Extra-Tropical Carbon Cycling Based on measurements of the Abundance and Isotopic Composition of Atmospheric CO2

    SciTech Connect (OSTI)

    Keeling, Ralph

    2014-12-12

    The objective of this project was to perform CO2 data syntheses and modeling activities to address two central questions: 1) how much has the seasonal cycle in atmospheric CO2 at northern high latitudes changed since the 1960s, and 2) how well do prognostic biospheric models represent these changes. This project also supported the continuation of the Scripps time series of CO2 isotopes and concentration at ten baseline stations distributed globally.

  1. Associative list processing unit

    DOE Patents [OSTI]

    Hemmert, Karl Scott; Underwood, Keith D.

    2013-01-29

    An associative list processing unit and method comprising employing a plurality of prioritized cell blocks and permitting inserts to occur in a single clock cycle if all of the cell blocks are not full. Also, an associative list processing unit and method comprising employing a plurality of prioritized cell blocks and using a tree of prioritized multiplexers descending from the plurality of cell blocks.

  2. Coupled modeling of a directly heated tubular solar receiver for supercritical carbon dioxide Brayton cycle: Structural and creep-fatigue evaluation

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

    Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Dutta, Pradip

    2016-06-06

    A supercritical carbon dioxide (sCO2) Brayton cycle is an emerging high energy-density cycle undergoing extensive research due to the appealing thermo-physical properties of sCO2 and single phase operation. Development of a solar receiver capable of delivering sCO2 at 20 MPa and 700 °C is required for implementation of the high efficiency (~50%) solar powered sCO2 Brayton cycle. In this work, extensive candidate materials are review along with tube size optimization using the ASME Boiler and Pressure Vessel Code. Moreover, temperature and pressure distribution obtained from the thermal-fluid modeling (presented in a complementary publication) are used to evaluate the thermal andmore » mechanical stresses along with detailed creep-fatigue analysis of the tubes. For resulting body stresses were used to approximate the lifetime performance of the receiver tubes. A cyclic loading analysis is performed by coupling the Strain-Life approach and the Larson-Miller creep model. The structural integrity of the receiver was examined and it was found that the stresses can be withstood by specific tubes, determined by a parametric geometric analysis. The creep-fatigue analysis display the damage accumulation due to cycling and the permanent deformation on the tubes showed that the tubes can operate for the full lifetime of the receiver.« less

  3. Evaluation of global horizontal irradiance to plane-of-array irradiance models at locations across the United States

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

    Lave, Matthew; Hayes, William; Pohl, Andrew; Hansen, Clifford W.

    2015-02-02

    We report an evaluation of the accuracy of combinations of models that estimate plane-of-array (POA) irradiance from measured global horizontal irradiance (GHI). This estimation involves two steps: 1) decomposition of GHI into direct and diffuse horizontal components and 2) transposition of direct and diffuse horizontal irradiance (DHI) to POA irradiance. Measured GHI and coincident measured POA irradiance from a variety of climates within the United States were used to evaluate combinations of decomposition and transposition models. A few locations also had DHI measurements, allowing for decoupled analysis of either the decomposition or the transposition models alone. Results suggest that decompositionmore » models had mean bias differences (modeled versus measured) that vary with climate. Transposition model mean bias differences depended more on the model than the location. Lastly, when only GHI measurements were available and combinations of decomposition and transposition models were considered, the smallest mean bias differences were typically found for combinations which included the Hay/Davies transposition model.« less

  4. SU-E-T-557: Monte Carlo Modeling of Philips RT-250 Orthovoltage Unit for Beam Spectrum Modulation

    SciTech Connect (OSTI)

    Reynoso, F; Cho, S

    2015-06-15

    Purpose: To develop and validate a Monte Carlo (MC) model of a Phillips RT-250 orthovoltage unit to test various beam spectrum modulation strategies for in vitro/vivo studies. A model of this type would enable the production of unconventional beams from a typical orthovoltage unit for novel therapeutic applications such as gold nanoparticle-aided radiotherapy. Methods: The MCNP5 code system was used to create a MC model of the head of RT-250 and a 30 × 30 × 30 cm{sup 3} water phantom. For the x-ray machine head, the current model includes the vacuum region, beryllium window, collimators, inherent filters and exterior steel housing. For increased computational efficiency, the primary x-ray spectrum from the target was calculated from a well-validated analytical software package. Calculated percentage-depth-dose (PDD) values and photon spectra were validated against experimental data from film and Compton-scatter spectrum measurements. Results: The model was validated for three common settings of the machine namely, 250 kVp (0.25 mm Cu), 125 kVp (2 mm Al), and 75 kVp (2 mm Al). The MC results for the PDD curves were compared with film measurements and showed good agreement for all depths with a maximum difference of 4 % around dmax and under 2.5 % for all other depths. The primary photon spectra were also measured and compared with the MC results showing reasonable agreement between the two, validating the input spectra and the final spectra as predicted by the current MC model. Conclusion: The current MC model accurately predicted the dosimetric and spectral characteristics of each beam from the RT-250 orthovoltage unit, demonstrating its applicability and reliability for beam spectrum modulation tasks. It accomplished this without the need to model the bremsstrahlung xray production from the target, while significantly improved on computational efficiency by at least two orders of magnitude. Supported by DOD/PCRP grant W81XWH-12-1-0198.

  5. Optimization of a Nucleic Acids united-RESidue 2-Point model (NARES-2P) with a maximum-likelihood approach

    SciTech Connect (OSTI)

    He, Yi; Scheraga, Harold A.; Liwo, Adam

    2015-12-28

    Coarse-grained models are useful tools to investigate the structural and thermodynamic properties of biomolecules. They are obtained by merging several atoms into one interaction site. Such simplified models try to capture as much as possible information of the original biomolecular system in all-atom representation but the resulting parameters of these coarse-grained force fields still need further optimization. In this paper, a force field optimization method, which is based on maximum-likelihood fitting of the simulated to the experimental conformational ensembles and least-squares fitting of the simulated to the experimental heat-capacity curves, is applied to optimize the Nucleic Acid united-RESidue 2-point (NARES-2P) model for coarse-grained simulations of nucleic acids recently developed in our laboratory. The optimized NARES-2P force field reproduces the structural and thermodynamic data of small DNA molecules much better than the original force field.

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

    SciTech Connect (OSTI)

    2008-05-19

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

  7. Prospective life-cycle modeling of a carbon capture and storage system using metal-organic frameworks for CO2 capture

    SciTech Connect (OSTI)

    Sathre, R; Masanet, E

    2013-01-01

    Metal-organic frameworks (MOFs) are promising new material media for carbon dioxide (CO2) capture. Their tunable adsorption patterns may allow relatively efficient separation of gases, e.g. from power plant exhaust. Here we conduct scenario-based prospective life-cycle system modeling to estimate the potentials and implications of large-scale MOF application for post-combustion carbon capture and storage (CCS), and estimate the source and magnitude of uncertainties. The methodological approach includes parametric system modeling to quantify relations between system components; scenario projections of plausible pathways for system scale-up; proxy data on analogous materials and processes; and uncertainty analysis of parameter significance. We estimate the system-wide material and energy flows and economic costs associated with projected large-scale CCS deployment. We compare the performance of a MOF-based system to currently more mature amine-based capture technology. We discuss balancing two critical factors that determine the success of CO2 capture media: thermodynamic efficiency of the capture/regeneration cycle, and life-cycle embodied energy and cost of the material and its ancillary systems.

  8. Using landscape typologies to model socioecological systems: Application to agriculture of the United States Gulf Coast

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

    Preston, Benjamin L.; King, Anthony Wayne; Mei, Rui; Nair, Sujithkumar Surendran

    2016-02-11

    Agricultural enterprises are vulnerable to the effects of climate variability and change. Improved understanding of the determinants of vulnerability and adaptive capacity in agricultural systems is important for projecting and managing future climate risk. At present, three analytical tools dominate methodological approaches to understanding agroecological vulnerability to climate: process-based crop models, empirical crop models, and integrated assessment models. A common weakness of these approaches is their limited treatment of socio-economic conditions and human agency in modeling agroecological processes and outcomes. This study proposes a framework that uses spatial cluster analysis to generate regional socioecological typologies that capture geographic variance inmore » regional agricultural production and enable attribution of that variance to climatic, topographic, edaphic, and socioeconomic components. This framework was applied to historical corn production (1986-2010) in the U.S. Gulf of Mexico region as a testbed. The results demonstrate that regional socioeconomic heterogeneity is an important driving force in human dominated ecosystems, which we hypothesize, is a function of the link between socioeconomic conditions and the adaptive capacity of agricultural systems. Meaningful representation of future agricultural responses to climate variability and change is contingent upon understanding interactions among biophysical conditions, socioeconomic conditions, and human agency their incorporation in predictive models.« less

  9. Existing Whole-House Solutions Case Study: Community-Scale Energy Modeling - Southeastern United States

    SciTech Connect (OSTI)

    2014-12-01

    Community-scale energy modeling and testing are useful for determining energy conservation measures that will effectively reduce energy use. To that end, IBACOS analyzed pre-retrofit daily utility data to sort homes by energy consumption, allowing for better targeting of homes for physical audits. Following ASHRAE Guideline 14 normalization procedures, electricity consumption of 1,166 all-electric, production-built homes was modeled. The homes were in two communities: one built in the 1970s and the other in the mid-2000s.

  10. N Reactor core heatup sensitivity study for the 32-inch unit cell model

    SciTech Connect (OSTI)

    Martin, F.; Zimmerman, B.; Heard, F.

    1988-02-01

    A number of N Reactor core heatup studies have been performed using the TRUMP-BD computer code. These studies were performed to address questions concerning the dependency of results on potential variations in the material properties and/or modeling assumptions. This report described and documents a series of 31 TRUMP-BD runs that were performed to determine the sensitivity of calculated inner-fuel temperatures to a variety of TRUMP input parameters and also to a change in the node density in a high-temperature-gradient region. The results of this study are based on the 32-in. model. 18 refs., 17 figs., 2 tab.

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

    SciTech Connect (OSTI)

    Drici, Warda

    2003-08-01

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

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

    SciTech Connect (OSTI)

    Drici, Warda

    2004-02-01

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

  13. Hydraulic Hybrid and Conventional Parcel Delivery Vehicles' Measured Laboratory Fuel Economy on Targeted Drive Cycles

    SciTech Connect (OSTI)

    Lammert, M. P.; Burton, J.; Sindler, P.; Duran, A.

    2014-10-01

    This research project compares laboratory-measured fuel economy of a medium-duty diesel powered hydraulic hybrid vehicle drivetrain to both a conventional diesel drivetrain and a conventional gasoline drivetrain in a typical commercial parcel delivery application. Vehicles in this study included a model year 2012 Freightliner P100H hybrid compared to a 2012 conventional gasoline P100 and a 2012 conventional diesel parcel delivery van of similar specifications. Drive cycle analysis of 484 days of hybrid parcel delivery van commercial operation from multiple vehicles was used to select three standard laboratory drive cycles as well as to create a custom representative cycle. These four cycles encompass and bracket the range of real world in-use data observed in Baltimore United Parcel Service operations. The NY Composite cycle, the City Suburban Heavy Vehicle Cycle cycle, and the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) cycle as well as a custom Baltimore parcel delivery cycle were tested at the National Renewable Energy Laboratory's Renewable Fuels and Lubricants Laboratory. Fuel consumption was measured and analyzed for all three vehicles. Vehicle laboratory results are compared on the basis of fuel economy. The hydraulic hybrid parcel delivery van demonstrated 19%-52% better fuel economy than the conventional diesel parcel delivery van and 30%-56% better fuel economy than the conventional gasoline parcel delivery van on cycles other than the highway-oriented HHDDT cycle.

  14. Long-Term Modeling of Wind Energy in the United States

    SciTech Connect (OSTI)

    Kyle, G. Page; Smith, Steven J.; Wise, Marshall A.; Lurz, Joshua P.; Barrie, Daniel

    2007-09-30

    An improved representation of wind energy has been developed for the ObjECTS MiniCAM integrated assessment modeling framework. The first version of this wind model was used for the CCTP scenarios, where wind accounts for between 9% and 17% of U.S. electricity generation by 2095. Climate forcing stabilization policies tend to increase projected deployment. Accelerated technological development in wind electric generation can both increase output and reduce the costs of wind energy. In all scenarios, wind generation is constrained by its costs relative to alternate electricity sources, particularly as less favorable wind farm sites are utilized. These first scenarios were based on exogenous resource estimates that do not allow evaluation of resource availability assumptions. A more detailed representation of wind energy is under development that uses spatially explicit resource information and explicit wind turbine technology characteristics.

  15. Renewable Energy Cost Modeling. A Toolkit for Establishing Cost-Based Incentives in the United States

    SciTech Connect (OSTI)

    Gifford, Jason S.; Grace, Robert C.; Rickerson, Wilson H.

    2011-05-01

    This report serves as a resource for policymakers who wish to learn more about levelized cost of energy (LCOE) calculations, including cost-based incentives. The report identifies key renewable energy cost modeling options, highlights the policy implications of choosing one approach over the other, and presents recommendations on the optimal characteristics of a model to calculate rates for cost-based incentives, FITs, or similar policies. These recommendations shaped the design of NREL's Cost of Renewable Energy Spreadsheet Tool (CREST), which is used by state policymakers, regulators, utilities, developers, and other stakeholders to assist with analyses of policy and renewable energy incentive payment structures. Authored by Jason S. Gifford and Robert C. Grace of Sustainable Energy Advantage LLC and Wilson H. Rickerson of Meister Consultants Group, Inc.

  16. Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds

    SciTech Connect (OSTI)

    Krueger, Steven K.

    2008-03-03

    We used a cloud-resolving model (a detailed computer model of cloud systems) to evaluate and improve the representation of clouds in global atmospheric models used for numerical weather prediction and climate modeling. We also used observations of the atmospheric state, including clouds, made at DOE's Atmospheric Radiation Measurement (ARM) Program's Climate Research Facility located in the Southern Great Plains (Kansas and Oklahoma) during Intensive Observation Periods to evaluate our detailed computer model as well as a single-column version of a global atmospheric model used for numerical weather prediction (the Global Forecast System of the NOAA National Centers for Environmental Prediction). This so-called Single-Column Modeling approach has proved to be a very effective method for testing the representation of clouds in global atmospheric models. The method relies on detailed observations of the atmospheric state, including clouds, in an atmospheric column comparable in size to a grid column used in a global atmospheric model. The required observations are made by a combination of in situ and remote sensing instruments. One of the greatest problems facing mankind at the present is climate change. Part of the problem is our limited ability to predict the regional patterns of climate change. In order to increase this ability, uncertainties in climate models must be reduced. One of the greatest of these uncertainties is the representation of clouds and cloud processes. This project, and ARM taken as a whole, has helped to improve the representation of clouds in global atmospheric models.

  17. Modeling dolomitized carbonate-ramp reservoirs: A case study of the Seminole San Andres unit. Part 2 -- Seismic modeling, reservoir geostatistics, and reservoir simulation

    SciTech Connect (OSTI)

    Wang, F.P.; Dai, J.; Kerans, C.

    1998-11-01

    In part 1 of this paper, the authors discussed the rock-fabric/petrophysical classes for dolomitized carbonate-ramp rocks, the effects of rock fabric and pore type on petrophysical properties, petrophysical models for analyzing wireline logs, the critical scales for defining geologic framework, and 3-D geologic modeling. Part 2 focuses on geophysical and engineering characterizations, including seismic modeling, reservoir geostatistics, stochastic modeling, and reservoir simulation. Synthetic seismograms of 30 to 200 Hz were generated to study the level of seismic resolution required to capture the high-frequency geologic features in dolomitized carbonate-ramp reservoirs. Outcrop data were collected to investigate effects of sampling interval and scale-up of block size on geostatistical parameters. Semivariogram analysis of outcrop data showed that the sill of log permeability decreases and the correlation length increases with an increase of horizontal block size. Permeability models were generated using conventional linear interpolation, stochastic realizations without stratigraphic constraints, and stochastic realizations with stratigraphic constraints. Simulations of a fine-scale Lawyer Canyon outcrop model were used to study the factors affecting waterflooding performance. Simulation results show that waterflooding performance depends strongly on the geometry and stacking pattern of the rock-fabric units and on the location of production and injection wells.

  18. Modeling of an adsorption unit packed with amidoxime fiber balls for the recovery of uranium from seawater

    SciTech Connect (OSTI)

    Morooka, S.; Kato, T.; Inada, M.; Kago, T.; Kusakabe, K. )

    1991-01-01

    Amidoxime fiber adsorbents are prepared by treating commercial poly(acrylonitrile) fibers with NH{sub 2}OH in methanol and then with an aqueous NaOH solution. The rate of adsorption of uranium from seawater is 0.1-0.3 (g of U/kg of dry fiber)/day. The fiber is placed in 2-cm-diameter spherical shells of plastic net, and these fibrous balls are packed in a column. Seawater is assumed to flow through the packed bed by the kinetic force of the ocean current. The permeation velocity of liquid in each ball is evaluated with a small electrode that detects the electrochemical limiting current. When the permeation velocity is slow, most uranyl ions are adsorbed only in the peripheral part of the ball. In this paper a model of the packed bed absorption unit is proposed and a numerical calculation gives optimum values of design parameters.

  19. Decision support model for municipal solid waste recycling at United States Air Force Installations. Master`s thesis

    SciTech Connect (OSTI)

    Williams, G.A.

    1996-12-01

    The United States Air Force requires each installation to operate a municipal solid waste recycling program. Two inherently conflicting objectives, waste material diversion and financial result, have been established for the program. Reducing landfill disposal is the primary objective, but the incentive for profit is strong because each installation can retain profits from the program. Installations can be divided into two distinct areas, commercial and residential, based on the waste stream composition and funding. Structuring of the recycling program is often done in an ad-hoc manner. A decision support model was developed to evaluate four methods for each area. The model combines available Air Force data and information from research literature to determine the results of sixteen strategy combinations. The important variables affecting the results are determined through sensitivity analysis. The results are used to establish an efficient frontier of preferred strategies. The frontier illustrates the trade-offs of each strategy. The frontier can be also be used to inform decision makers prior to final strategy selection and determine preference values which would favor a given strategy. The value free analysis provides an objective foundation for presentation to a decision maker with unknown or changing preference values. The model provides valuable insight into the performance of recycling strategies as part of an overall waste management plan.

  20. Phase II Transport Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Revision 1

    SciTech Connect (OSTI)

    Gregg Ruskuaff

    2010-01-01

    This document, the Phase II Frenchman Flat transport report, presents the results of radionuclide transport simulations that incorporate groundwater radionuclide transport model statistical and structural uncertainty, and lead to forecasts of the contaminant boundary (CB) for a set of representative models from an ensemble of possible models. This work, as described in the Federal Facility Agreement and Consent Order (FFACO) Underground Test Area (UGTA) strategy (FFACO, 1996; amended 2010), forms an essential part of the technical basis for subsequent negotiation of the compliance boundary of the Frenchman Flat corrective action unit (CAU) by Nevada Division of Environmental Protection (NDEP) and National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Underground nuclear testing via deep vertical shafts was conducted at the Nevada Test Site (NTS) from 1951 until 1992. The Frenchman Flat area, the subject of this report, was used for seven years, with 10 underground nuclear tests being conducted. The U.S. Department of Energy (DOE), NNSA/NSO initiated the UGTA Project to assess and evaluate the effects of underground nuclear tests on groundwater at the NTS and vicinity through the FFACO (1996, amended 2010). The processes that will be used to complete UGTA corrective actions are described in the “Corrective Action Strategy” in the FFACO Appendix VI, Revision No. 2 (February 20, 2008).

  1. Modeling the Effects of Irrigation on Land Surface Fluxes and States over the Conterminous United States: Sensitivity to Input Data and Model Parameters

    SciTech Connect (OSTI)

    Leng, Guoyong; Huang, Maoyi; Tang, Qiuhong; Sacks, William J.; Lei, Huimin; Leung, Lai-Yung R.

    2013-09-16

    Previous studies on irrigation impacts on land surface fluxes/states were mainly conducted as sensitivity experiments, with limited analysis of uncertainties from the input data and model irrigation schemes used. In this study, we calibrated and evaluated the performance of irrigation water use simulated by the Community Land Model version 4 (CLM4) against observations from agriculture census. We investigated the impacts of irrigation on land surface fluxes and states over the conterminous United States (CONUS) and explored possible directions of improvement. Specifically, we found large uncertainty in the irrigation area data from two widely used sources and CLM4 tended to produce unrealistically large temporal variations of irrigation demand for applications at the water resources region scale over CONUS. At seasonal to interannual time scales, the effects of irrigation on surface energy partitioning appeared to be large and persistent, and more pronounced in dry than wet years. Even with model calibration to yield overall good agreement with the irrigation amounts from the National Agricultural Statistics Service (NASS), differences between the two irrigation area datasets still dominate the differences in the interannual variability of land surface response to irrigation. Our results suggest that irrigation amount simulated by CLM4 can be improved by (1) calibrating model parameter values to account for regional differences in irrigation demand and (2) accurate representation of the spatial distribution and intensity of irrigated areas.

  2. Truck Duty Cycle and Performance Data Collection and Analysis...

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

    More Documents & Publications Heavy Duty & Medium Duty Drive Cycle Data Collection for Modeling Expansion Truck Duty Cycle and Performance Data Collection and Analysis Program 2010 ...

  3. DESIGN OF HYBRID POWER GENERATION CYCLES EMPLOYING AMMONIA-WATER-CARBON DIOXIDE MIXTURES

    SciTech Connect (OSTI)

    Ashish Gupta

    2002-06-01

    A power cycle generates electricity from the heat of combustion of fossil fuels. Its efficiency is governed by the cycle configuration, the operating parameters, and the working fluid. Typical. designs use pure water as the fluid. in the last two decades, hybrid cycles based on ammonia-water, and carbon-dioxide mixtures as the working fluid have been proposed. These cycles may improve the power generation efficiency of Rankine cycles by 15%. Improved efficiency is important for two reasons: it lowers the cost of electricity being produced, and by reducing the consumption of fossil fuels per unit power, it reduces the generation of environmental pollutants. The goal of this project is to develop a computational optimization-based method for the design and analysis of hybrid bottoming power cycles to minimize the usage of fossil fuels. The development of this methodology has been achieved by formulating this task as that of selecting the least cost power cycle design from all possible configurations. They employ a detailed thermodynamic property prediction package they have developed under a DOE-FETC grant to model working fluid mixtures. Preliminary results from this work suggest that a pure NH{sub 3} cycle outperforms steam or the expensive Kalina cycle.

  4. UGE Scheduler Cycle Time

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

    UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Scheduler Cycle Time Genepool Jobs Dispatched / Hour What is the Scheduler Cycle? The Univa Grid Engine Scheduler cycle performs a number of important tasks, including: Prioritizing Jobs Reserving Resources for jobs requesting more resources (slots / memory) Dispatching jobs or tasks to the compute nodes Evaluating job dependencies The "cycle time" is the length of time it takes the scheduler to complete all

  5. Differences in carbon cycle and temperature projections from emission- and concentration-driven earth system model simulations

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

    Shao, P.; Zeng, X.; Zeng, X.

    2014-08-29

    The influence of prognostic and prescribed atmospheric CO2 concentrations ([CO2]) on the carbon uptake and temperature is investigated using all eight Earth System Models (ESMs) with relevant output variables from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Under the RCP8.5 scenario, the projected [CO2] differences in 2100 vary from -19.7 to +207.3 ppm in emission-driven ESMs. Incorporation of the interactive concentrations also increases the range of global warming, computed as the 20 year average difference between 20812100 and 18501869/18611880, by 49% from 2.36 K (i.e. ranging from 3.11 to 5.47 K) in the concentration-driven simulations to 3.51 K inmorethe emission-driven simulations. The observed seasonal amplitude of global [CO2] from 19802011 is about 1.25.3 times as large as those from the eight emission-driven ESMs, while the [CO2] seasonality is simply neglected in concentration-driven ESMs, suggesting the urgent need of ESM improvements in this area. The temperature-concentration feedback parameter ? is more sensitive to [CO2] (e.g. during 19802005 versus 20752100) than how [CO2] is handled (i.e. prognostic versus prescribed). This sensitivity can be substantially reduced by using a more appropriate parameter ?' computed from the linear regression of temperature change versus that of the logarithm of [CO2]. However, the inter-model relative variations of both ? and ?' remain large, suggesting the need of more detailed studies to understand and hopefully reduce these discrepancies.less

  6. Models of carbon flow in tropical ecosystems with emphasis on their role in the global carbon cycle. Final report, September 15, 1978-September 14, 1980

    SciTech Connect (OSTI)

    Brown, S.; Lugo, A.E.

    1980-01-01

    The role of tropical forests on the carbon balance of the world is studied with four different approaches: (1) to quantify the area of tropical forests and the changes in forest cover; (2) to calculate the storage and production of organic carbon in tropical forests; (3) the modelling of land use changes in tropical countries using computer simulation models; and (4) the synthesis of information from many sources into conceptual schemes using Life Zone and energy use concepts. Results are not yet conclusive but indicate that tropical forests play a significant role in the global carbon cycle, and they are likely to be small sources of carbon to the atmosphere. The basis for this statement is: (1) the large area of tropical forests do not appear to be changing as fast as suggested earlier; (2) the storage of carbon in the tropics is about one half as previously suggested; (3) the turnover of carbon in the tropics is very fast with large exports to the ocean via rivers; and (4) models of land use change using data from Bolivia show only a small net addition of carbon to the atmosphere.

  7. Generation of Collapsed Cross Sections for Hatch 1 Cycles 1-3

    SciTech Connect (OSTI)

    Ade, Brian J

    2012-11-01

    Under NRC JCN V6361, Oak Ridge National Laboratory (ORNL) was tasked to develop and run SCALE/TRITON models for generation of collapsed few-group cross sections and to convert the cross sections to PMAXS format using the GENPMAXS conversion utility for use in PARCS/PATHS simulations of Hatch Unit 1, cycles 1-3. This letter report documents the final models used to produce the Hatch collapsed cross sections.

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

    SciTech Connect (OSTI)

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

    2005-04-01

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

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

    SciTech Connect (OSTI)

    John McCord

    2004-12-01

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

  10. Advanced Fuel Cycle Economic Sensitivity Analysis

    SciTech Connect (OSTI)

    David Shropshire; Kent Williams; J.D. Smith; Brent Boore

    2006-12-01

    A fuel cycle economic analysis was performed on four fuel cycles to provide a baseline for initial cost comparison using the Gen IV Economic Modeling Work Group G4 ECON spreadsheet model, Decision Programming Language software, the 2006 Advanced Fuel Cycle Cost Basis report, industry cost data, international papers, the nuclear power related cost study from MIT, Harvard, and the University of Chicago. The analysis developed and compared the fuel cycle cost component of the total cost of energy for a wide range of fuel cycles including: once through, thermal with fast recycle, continuous fast recycle, and thermal recycle.

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

    SciTech Connect (OSTI)

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

    2009-01-31

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

  12. Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model

    SciTech Connect (OSTI)

    Liang Sai; Zhang, Tianzhu; Xu Yijian

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Using crop straws and wood wastes for paper production should be promoted. Black-Right-Pointing-Pointer Bagasse and textile waste recycling should be properly limited. Black-Right-Pointing-Pointer Imports of scrap paper should be encouraged. Black-Right-Pointing-Pointer Sensitivity analysis, uncertainties and policy implications are discussed. - Abstract: Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China's paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment.

  13. Coupled modeling of a directly heated tubular solar receiver for supercritical carbon dioxide Brayton cycle: Optical and thermal-fluid evaluation

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

    Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Yellowhair, Julius; Dutta, Pradip

    2016-05-30

    In single phase performance and appealing thermo-physical properties supercritical carbon dioxide (s-CO2) make a good heat transfer fluid candidate for concentrating solar power (CSP) technologies. The development of a solar receiver capable of delivering s-CO2 at outlet temperatures ~973 K is required in order to merge CSP and s-CO2 Brayton cycle technologies. A coupled optical and thermal-fluid modeling effort for a tubular receiver is undertaken to evaluate the direct tubular s-CO2 receiver’s thermal performance when exposed to a concentrated solar power input of ~0.3–0.5 MW. Ray tracing, using SolTrace, is performed to determine the heat flux profiles on the receivermore » and computational fluid dynamics (CFD) determines the thermal performance of the receiver under the specified heating conditions. Moreover, an in-house MATLAB code is developed to couple SolTrace and ANSYS Fluent. CFD modeling is performed using ANSYS Fluent to predict the thermal performance of the receiver by evaluating radiation and convection heat loss mechanisms. Understanding the effects of variation in heliostat aiming strategy and flow configurations on the thermal performance of the receiver was achieved through parametric analyses. Finally, a receiver thermal efficiency ~85% was predicted and the surface temperatures were observed to be within the allowable limit for the materials under consideration.« less

  14. Coupled ocean-atmosphere model system for studies of interannual-to-decadal climate variability over the North Pacific Basin and precipitation over the Southwestern United States

    SciTech Connect (OSTI)

    Lai, Chung-Chieng A.

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The ultimate objective of this research project is to make understanding and predicting regional climate easier. The long-term goals of this project are (1) to construct a coupled ocean-atmosphere model (COAM) system, (2) use it to explore the interannual-to-decadal climate variability over the North Pacific Basin, and (3) determine climate effects on the precipitation over the Southwestern United States. During this project life, three major tasks were completed: (1) Mesoscale ocean and atmospheric model; (2) global-coupled ocean and atmospheric modeling: completed the coupling of LANL POP global ocean model with NCAR CCM2+ global atmospheric model; and (3) global nested-grid ocean modeling: designed the boundary interface for the nested-grid ocean models.

  15. 2013 Planning Cycle

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

    Projects Expand Projects Skip navigation links Ancillary and Control Area Services (ACS) Practices Forum Attachment K 2015 Planning Cycle 2014 Planning Cycle 2013 Planning...

  16. 2014 Planning Cycle

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

    Projects Expand Projects Skip navigation links Ancillary and Control Area Services (ACS) Practices Forum Attachment K 2015 Planning Cycle 2014 Planning Cycle 2013 Planning...

  17. 2015 Planning Cycle

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

    Projects Expand Projects Skip navigation links Ancillary and Control Area Services (ACS) Practices Forum Attachment K 2015 Planning Cycle 2014 Planning Cycle 2013 Planning...

  18. Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model

    SciTech Connect (OSTI)

    Khangaonkar, Tarang; Sackmann, Brandon S.; Long, Wen; Mohamedali, Teizeen; Roberts, Mindy

    2012-08-14

    Nutrient pollution from rivers, nonpoint source runoff, and nearly 100 wastewater discharges is a potential threat to the ecological health of Puget Sound with evidence of hypoxia in some basins. However, the relative contributions of loads entering Puget Sound from natural and anthropogenic sources, and the effects of exchange flow from the Pacific Ocean are not well understood. Development of a quantitative model of Puget Sound is thus presented to help improve our understanding of the annual biogeochemical cycles in this system using the unstructured grid Finite Volume Coastal Ocean Model (FVCOM) framework and the Integrated Compartment Model (CE QUAL-ICM) water quality kinetics. Results based on 2006 data show that phytoplankton growth and die-off, succession between two species of algae, nutrient dynamics, and dissolved oxygen in Puget Sound are strongly tied to seasonal variation of temperature, solar radiation, and the annual exchange and flushing induced by upwelled Pacific Ocean waters. Concentrations in the mixed outflow surface layer occupying approximately 5?20 m of the upper water column show strong effects of eutrophication from natural and anthropogenic sources, spring and summer algae blooms, accompanied by depleted nutrients but high dissolved oxygen levels. The bottom layer reflects dissolved oxygen and nutrient concentrations of upwelled Pacific Ocean water modulated by mixing with biologically active surface outflow in the Strait of Juan De Fuca prior to entering Puget Sound over the Admiralty Inlet. The effect of reflux mixing at the Admiralty Inlet sill resulting in lower nutrient and higher dissolved oxygen levels in bottom waters of Puget Sound than the incoming upwelled Pacific Ocean water is reproduced. By late winter, with the reduction in algal activity, water column constituents of interest, were renewed and the system appeared to reset with cooler temperature, higher nutrient, and higher dissolved oxygen waters from the Pacific Ocean.

  19. CASL-U-2015-0248-000 Modeling Boiling Water Reactor

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

    8-000 Modeling Boiling Water Reactor Designs using MPACT Andrew P. Fitzgerald Brendan ... lattices from the Peach Bottom Unit 2 Reactor Cycles 1 and 2. ATRIUM TM 10 simulations ...

  20. The DOE water cycle pilot study.

    SciTech Connect (OSTI)

    Miller, N. L.; King, A. W.; Miller, M. A.; Springer, E. P.; Wesely, M. L.; Bashford, K. E.; Conrad, M. E.; Costigan, K.; Foster, P. N.; Gibbs, H. K.; Jin, J.; Klazura, J.; Lesht, B. M.; Machavaram, M. V.; Pan, F.; Song, J.; Troyan, D.; Washngton-Allen, R. A.; Environmental Research; LBNL; ORNL; BNL; LANL

    2005-03-01

    Regional Climate Simulations (Takle et al. 1999), and model uncertainties within land surface models are being evaluated within the Program to Intercompare Land Surface Schemes (e.g., Henderson-Sellers 1993; Wood et al. 1998; Lohmann et al. 1998). In the context of understanding the water budget at watershed scales, the following two research questions that highlight DOE's unique water isotope analysis and high-performance modeling capabilities were posed as the foci of this pilot study: (1) Can the predictability of the regional water budget be improved using high-resolution model simulations that are constrained and validated with new hydrospheric water measurements? (2) Can water isotopic tracers be used to segregate different pathways through the water cycle and predict a change in regional climate patterns? To address these questions, numerical studies using regional atmospheric-land surface models and multiscale land surface hydrologic models were generated and, to the extent possible, the results were evaluated with observations. While the number of potential processes that may be important in the local water budget is large, several key processes were examined in detail. Most importantly, a concerted effort was made to understand water cycle processes and feedbacks at the land surface-atmosphere interface at spatial scales ranging from 30 m to hundreds of kilometers. A simple expression for the land surface water budget at the watershed scale is expressed as {Delta}S = P + G{sub in} - ET - Q - G{sub out}, where {Delta}S is the change in water storage, P is precipitation, ET is evapotranspiration, Q is streamflow, G{sub in} is groundwater entering the watershed, and G{sub out} is groundwater leaving the watershed, per unit time. The WCPS project identified data gaps and necessary model improvements that will lead to a more accurate representation of the terms in Eq. (1). Table 1 summarizes the components of this water cycle pilot study and the respective

  1. Life-Cycle Evaluation of Concrete Building Construction as a Strategy for Sustainable Cities

    SciTech Connect (OSTI)

    Stadel, Alexander; Gursel, Petek; Masanet, Eric

    2012-01-18

    Structural materials in commercial buildings in the United States account for a significant fraction of national energy use, resource consumption, and greenhouse gas (GHG) emissions. Robust decisions for balancing and minimizing these various environmental effects require that structural materials selections follow a life-cycle, systems modeling approach. This report provides a concise overview of the development and use of a new life-cycle assessment (LCA) model for structural materials in U.S. commercial buildings-the Berkeley Lab Building Materials Pathways (B-PATH) model. B-PATH aims to enhance environmental decision-making in the commercial building LCA, design, and planning communities through the following key features: (1) Modeling of discrete technology options in the production, transportation, construction, and end of life processes associated U.S. structural building materials; (2) Modeling of energy supply options for electricity provision and directly combusted fuels across the building life cycle; (3) Comprehensiveness of relevant building mass and energy flows and environmental indicators; (4) Ability to estimate modeling uncertainties through easy creation of different life-cycle technology and energy supply pathways for structural materials; and (5) Encapsulation of the above features in a transparent public use model. The report summarizes literature review findings, methods development, model use, and recommendations for future work in the area of LCA for commercial buildings.

  2. HUMID AIR TURBINE CYCLE TECHNOLOGY DEVELOPMENT PROGRAM

    SciTech Connect (OSTI)

    Richard Tuthill

    2002-07-18

    The Humid Air Turbine (HAT) Cycle Technology Development Program focused on obtaining HAT cycle combustor technology that will be the foundation of future products. The work carried out under the auspices of the HAT Program built on the extensive low emissions stationary gas turbine work performed in the past by Pratt & Whitney (P&W). This Program is an integral part of technology base development within the Advanced Turbine Systems Program at the Department of Energy (DOE) and its experiments stretched over 5 years. The goal of the project was to fill in technological data gaps in the development of the HAT cycle and identify a combustor configuration that would efficiently burn high moisture, high-pressure gaseous fuels with low emissions. The major emphasis will be on the development of kinetic data, computer modeling, and evaluations of combustor configurations. The Program commenced during the 4th Quarter of 1996 and closed in the 4th Quarter of 2001. It teamed the National Energy Technology Laboratory (NETL) with P&W, the United Technologies Research Center (UTRC), and a subcontractor on-site at UTRC, kraftWork Systems Inc. The execution of the program started with bench-top experiments that were conducted at UTRC for extending kinetic mechanisms to HAT cycle temperature, pressure, and moisture conditions. The fundamental data generated in the bench-top experiments was incorporated into the analytical tools available at P&W to design the fuel injectors and combustors. The NETL then used the hardware to conduct combustion rig experiments to evaluate the performance of the combustion systems at elevated pressure and temperature conditions representative of the HAT cycle. The results were integrated into systems analysis done by kraftWork to verify that sufficient understanding of the technology had been achieved and that large-scale technological application and demonstration could be undertaken as follow-on activity. An optional program extended the

  3. Wave propagation method for Stirling engine cycle simulation: An experimental validation

    SciTech Connect (OSTI)

    Calandrelli, L.; Rispoli, F.

    1995-12-31

    A thermo-fluid-dynamic model for Stirling Engine Cycle simulation, first proposed by Rispoli in 1986, has been modified to keep into account the effect of gas axial turbulent conductivity and the results of recent research in oscillating flow friction and turbulent transition phenomena. Sudden cross sectional area changes are handled as flow discontinuities described by a set of equations solved by means of the secant method. Model prediction accuracy has been tested comparing numerical results with experimental data for the cogenerative unit V160. The comparison between numerical and experimental data shows model`s capability to take into account physical phenomena involved in working fluid evolution.

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

    SciTech Connect (OSTI)

    John McCord

    2006-05-01

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

  5. Fuel Cycle Subcommittee

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

    to NEAC Fuel Cycle Subcommittee Meeting of May 1, 2014 Washington, DC May 28, 2014 Al ... for the May 1, 2014 Fuel Cycle Subcommittee meeting and list of presenters is given below. ...

  6. Water Cycle Pilot Study

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

    1 Water Cycle Pilot Study To learn more about Earth's water cycle, the U.S. Department of Energy (DOE) has established a multi-laboratory science team representing five DOE ...

  7. ARM - The Hydrologic Cycle

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

    Hydrologic Cycle Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans The Hydrologic Cycle The hydrologic cycle is the cycle through which water passes from sea to land and from land to sea. Water vapor enters the air through the evaporation of water. Water vapor in the air eventually condenses

  8. United States

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

    EA- 3 14 Order Authorizing Electricity Exports to Mexico Order No. EA-3 14 February ... to transmit electric energy from the United States to Mexico as a power marketer. ...

  9. United States

    Office of Legacy Management (LM)

    Office of Research and EPA 600/R-941209 Environmental Protection Development January 1993 Agency Washington, DC 20460 Offsite Environmental 57,,7 Monitoring Report Radiation Monitoring Around United States Nuclear Test Areas, Calendar Year 1992 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY OFFICE OF RESEARCH AND DEVELOPMENT ENVIRONMENTAL MONITORING SYSTEMS LABORATORY-LAS VEGAS P.O. BOX 93478 LAS VEGAS. NEVADA 891 93-3478 702/798-2100 Dear Reader: Since 1954, the U.S. Environmental Protection

  10. GAX absorption cycle design process

    SciTech Connect (OSTI)

    Priedeman, D.K.; Christensen, R.N.

    1999-07-01

    This paper presents an absorption system design process that relies on computer simulations that are validated by experimental findings. An ammonia-water absorption heat pump cycle at 3 refrigeration tons (RT) and chillers at 3.3 RT and 5 RT (10.5 kW, 11.6 kW, and 17.6 kW) were initially modeled and then built and tested. The experimental results were used to calibrate both the cycle simulation and the component simulations, yielding computer design routines that could accurately predict component and cycle performance. Each system was a generator-absorber heat exchange (GAX) cycle, and all were sized for residential and light commercial use, where very little absorption equipment is currently used. The specific findings of the 5 RT (17.6 kW) chiller are presented. Modeling incorporated a heat loss from the gas-fired generator and pressure drops in both the evaporator and absorber. Simulation results and experimental findings agreed closely and validated the modeling method and simulation software.

  11. OSPREY Model

    SciTech Connect (OSTI)

    Veronica J. Rutledge

    2013-01-01

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed within Multi-physics Object Oriented Simulation Environment (MOOSE) developed at the Idaho National Laboratory (INL). Off-gas Separation and REcoverY (OSPREY) models the adsorption of off-gas constituents for dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions. Inputs to the model include gas, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. The simulation outputs component concentrations along the column length as a function of time from which breakthrough data is obtained. The breakthrough data can be used to determine bed capacity, which in turn can be used to size columns. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data and parameters were input into the adsorption model to develop models specific for krypton adsorption. The same can be done for iodine, xenon, and tritium. The model will be validated with experimental breakthrough curves. Customers will be given access to

  12. Comprehensive Energy Assessment: EE and RE Project Optimization Modeling for United States Pacific Command (USPACOM) American Recovery and Reinvestment Act (ARRA) FEMP Technical Assistance

    SciTech Connect (OSTI)

    Brigantic, Robert T.; Papatyi, Anthony F.; Perkins, Casey J.

    2010-09-30

    This report summarizes a study and corresponding model development conducted in support of the United States Pacific Command (USPACOM) as part of the Federal Energy Management Program (FEMP) American Reinvestment and Recovery Act (ARRA). This research was aimed at developing a mathematical programming framework and accompanying optimization methodology in order to simultaneously evaluate energy efficiency (EE) and renewable energy (RE) opportunities. Once developed, this research then demonstrated this methodology at a USPACOM installation - Camp H.M. Smith, Hawaii. We believe this is the first time such an integrated, joint EE and RE optimization methodology has been constructed and demonstrated.

  13. Renewable Energy Cost Modeling: A Toolkit for Establishing Cost-Based Incentives in the United States; March 2010 -- March 2011

    SciTech Connect (OSTI)

    Gifford, J. S.; Grace, R. C.; Rickerson, W. H.

    2011-05-01

    This report is intended to serve as a resource for policymakers who wish to learn more about establishing cost-based incentives. The report will identify key renewable energy cost modeling options, highlight the policy implications of choosing one approach over the other, and present recommendations on the optimal characteristics of a model to calculate rates for cost-based incentives, feed-in tariffs (FITs), or similar policies. These recommendations will be utilized in designing the Cost of Renewable Energy Spreadsheet Tool (CREST). Three CREST models will be publicly available and capable of analyzing the cost of energy associated with solar, wind, and geothermal electricity generators. The CREST models will be developed for use by state policymakers, regulators, utilities, developers, and other stakeholders to assist them in current and future rate-setting processes for both FIT and other renewable energy incentive payment structures and policy analyses.

  14. Overview of the Special Issue: A Multi-Model Framework to Achieve Consistent Evaluation of Climate Change Impacts in the United States

    SciTech Connect (OSTI)

    Waldhoff, Stephanie T.; Martinich, Jeremy; Sarofim, Marcus; DeAngelo, B. J.; McFarland, Jim; Jantarasami, Lesley; Shouse, Kate C.; Crimmins, Allison; Ohrel, Sara; Li, Jia

    2015-07-01

    The Climate Change Impacts and Risk Analysis (CIRA) modeling exercise is a unique contribution to the scientific literature on climate change impacts, economic damages, and risk analysis that brings together multiple, national-scale models of impacts and damages in an integrated and consistent fashion to estimate climate change impacts, damages, and the benefits of greenhouse gas (GHG) mitigation actions in the United States. The CIRA project uses three consistent socioeconomic, emissions, and climate scenarios across all models to estimate the benefits of GHG mitigation policies: a Business As Usual (BAU) and two policy scenarios with radiative forcing (RF) stabilization targets of 4.5 W/m2 and 3.7 W/m2 in 2100. CIRA was also designed to specifically examine the sensitivity of results to uncertainties around climate sensitivity and differences in model structure. The goals of CIRA project are to 1) build a multi-model framework to produce estimates of multiple risks and impacts in the U.S., 2) determine to what degree risks and damages across sectors may be lowered from a BAU to policy scenarios, 3) evaluate key sources of uncertainty along the causal chain, and 4) provide information for multiple audiences and clearly communicate the risks and damages of climate change and the potential benefits of mitigation. This paper describes the motivations, goals, and design of the CIRA modeling exercise and introduces the subsequent papers in this special issue.

  15. Dynamic Modeling of Learning in Emerging Energy Industries: The Example of Advanced Biofuels in the United States: Preprint

    SciTech Connect (OSTI)

    Vimmerstedt, Laura J.; Bush, Brian W.; Peterson, Steven O.

    2015-09-03

    This paper (and its supplemental model) presents novel approaches to modeling interactions and related policies among investment, production, and learning in an emerging competitive industry. New biomass-to-biofuels pathways are being developed and commercialized to support goals for U.S. advanced biofuel use, such as those in the Energy Independence and Security Act of 2007. We explore the impact of learning rates and techno-economics in a learning model excerpted from the Biomass Scenario Model (BSM), developed by the U.S. Department of Energy and the National Renewable Energy Laboratory to explore the impact of biofuel policy on the evolution of the biofuels industry. The BSM integrates investment, production, and learning among competing biofuel conversion options that are at different stages of industrial development. We explain the novel methods used to simulate the impact of differing assumptions about mature industry techno-economics and about learning rates while accounting for the different maturity levels of various conversion pathways. A sensitivity study shows that the parameters studied (fixed capital investment, process yield, progress ratios, and pre-commercial investment) exhibit highly interactive effects, and the system, as modeled, tends toward market dominance of a single pathway due to competition and learning dynamics.

  16. Fuel Cycle Subcommittee

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

    to NEAC Fuel Cycle Subcommittee Meeting of October 30, 2014 Washington, DC December 1, 2014 Al Sattelberger (Chair), Carol Burns, Margaret Chu, Raymond Juzaitis, Chris Kouts, Sekazi Mtingwa, Ronald Omberg, Joy Rempe, Dominique Warin I. Introduction 1 The agenda for the October 30, 2014 Fuel Cycle Subcommittee meeting is given below. The meeting provided members an overview of various research efforts funded by the Department of Energy Office of Nuclear Energy (DOE-NE) Fuel Cycle Technologies

  17. Fuel Cycle Subcommittee

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

    Report to NEAC Fuel Cycle Subcommittee Meeting of October 22, 2015 Washington, DC December 7, 2015 Al Sattelberger (Chair), Carol Burns, Margaret Chu, Raymond Juzaitis, Chris Kouts, Sekazi Mtingwa, Ronald Omberg, Joy Rempe, Dominique Warin 2 I. Introduction The agenda for the October 22, 2015 Fuel Cycle Subcommittee meeting is given below. The meeting provided members an overview of several research efforts funded by the DOE Office of Nuclear Energy's Fuel Cycle Technologies (FCT) program and

  18. Impacts of Rising Air Temperatures and Emissions Mitigation on Electricity Demand and Supply in the United States. A Multi-Model Comparison

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

    McFarland, James; Zhou, Yuyu; Clarke, Leon; Sullivan, Patrick; Colman, Jesse; Jaglom, Wendy S.; Colley, Michelle; Patel, Pralit; Eom, Jiyon; Kim, Son H.; et al

    2015-06-10

    The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Fewer studies have explored the physical impacts of climate change on the power sector. Our present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effectsmore » of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. Moreover, the increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.« less

  19. Impacts of Rising Air Temperatures and Emissions Mitigation on Electricity Demand and Supply in the United States. A Multi-Model Comparison

    SciTech Connect (OSTI)

    McFarland, James; Zhou, Yuyu; Clarke, Leon; Sullivan, Patrick; Colman, Jesse; Jaglom, Wendy S.; Colley, Michelle; Patel, Pralit; Eom, Jiyon; Kim, Son H.; Kyle, G. Page; Schultz, Peter; Venkatesh, Boddu; Haydel, Juanita; Mack, Charlotte; Creason, Jared

    2015-06-10

    The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Fewer studies have explored the physical impacts of climate change on the power sector. Our present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effects of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. Moreover, the increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.

  20. Impacts of rising air temperatures and emissions mitigation on electricity demand and supply in the United States: a multi-model comparison

    SciTech Connect (OSTI)

    McFarland, Jim; Zhou, Yuyu; Clarke, Leon E.; Sullivan, Patrick; Colman, Jesse; Jaglom, Wendy; Colley, Michelle; Patel, Pralit L.; Eom, Jiyong; Kim, Son H.; Kyle, G. Page; Schultz, Peter; Venkatesh, Boddu; Haydel, Juanita; Mack, Charlotte; Creason, Jared

    2015-10-09

    The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Yet fewer studies have explored the physical impacts of climate change on the power sector. The present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effects of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. The increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.

  1. Erratum to: Impacts of rising air temperatures and emissions mitigation on electricity demand and supply in the United States: a multi-model comparison

    SciTech Connect (OSTI)

    McFarland, Jim; Zhou, Yuyu; Clarke, Leon E.; Sullivan, Patrick; Colman, Jesse; Jaglom, Wendy; Colley, Michelle; Patel, Pralit L.; Eom, Jiyong; Kim, Son H.; Kyle, G. Page; Schultz, Peter; Venkatesh, Boddu; Haydel, Juanita; Mack, Charlotte; Creason, Jared

    2015-10-07

    The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Yet fewer studies have explored the physical impacts of climate change on the power sector. The present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effects of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. The increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.

  2. "Integrated Gasification Combined Cycle"

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

    Turbine",,"X" " - Heat Recovery Steam Generator",,,"X" " - Gasifier",,"X" " - Balance of Plant",,,"X" "Conventional Natural Gas Combined Cycle" " - Conventional Combustion Turbine"...

  3. 10 MWe power cycle

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

    MWe power cycle - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy ...

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

    SciTech Connect (OSTI)

    Joel Sminchak

    2011-09-30

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

  5. Pipeline bottoming cycle study. Final report

    SciTech Connect (OSTI)

    Not Available

    1980-06-01

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  6. Model Evaluation Report for Corrective Action Unit 98: Frenchman Flat, Nevada National Security Site, Nye County, Nevada, Revision 1

    SciTech Connect (OSTI)

    Ruskauff, Greg; Marutzky, Sam

    2014-09-01

    Model evaluation focused solely on the PIN STRIPE and MILK SHAKE underground nuclear tests’ contaminant boundaries (CBs) because they had the largest extent, uncertainty, and potential consequences. The CAMBRIC radionuclide migration experiment also had a relatively large CB, but because it was constrained by transport data (notably Well UE-5n), there was little uncertainty, and radioactive decay reduced concentrations before much migration could occur. Each evaluation target and the associated data-collection activity were assessed in turn to determine whether the new data support, or demonstrate conservatism of, the CB forecasts. The modeling team—in this case, the same team that developed the Frenchman Flat geologic, source term, and groundwater flow and transport models—analyzed the new data and presented the results to a PER committee. Existing site understanding and its representation in numerical groundwater flow and transport models was evaluated in light of the new data and the ability to proceed to the CR stage of long-term monitoring and institutional control.

  7. Life Cycle Cost Estimate

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-03-28

    Life-cycle costs (LCCs) are all the anticipated costs associated with a project or program alternative throughout its life. This includes costs from pre-operations through operations or to the end of the alternative.This chapter discusses life cycle costs and the role they play in planning.

  8. Power Plant Cycling Costs

    SciTech Connect (OSTI)

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  9. " Million Housing Units, Final...

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

    ... Vacant housing units, seasonal units, second homes, military housing, and group quarters ... Vacant housing units, seasonal units, second homes, military housing, and group quarters ...

  10. " Million Housing Units, Final"

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

    ... Vacant housing units, seasonal units, second homes, military housing, and group quarters ... Vacant housing units, seasonal units, second homes, military housing, and group quarters ...

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

    SciTech Connect (OSTI)

    Bechtel Nevada

    2005-09-01

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

  12. FUEL CYCLE POTENTIAL WASTE FOR DISPOSITION

    SciTech Connect (OSTI)

    Jones, R.; Carter, J.

    2010-10-13

    The United States (U.S.) currently utilizes a once-through fuel cycle where used nuclear fuel (UNF) is stored on-site in either wet pools or in dry storage systems with ultimate disposal in a deep mined geologic repository envisioned. Within the Department of Energy's (DOE) Office of Nuclear Energy (DOE-NE), the Fuel Cycle Research and Development Program (FCR&D) develops options to the current commercial fuel cycle management strategy to enable the safe, secure, economic, and sustainable expansion of nuclear energy while minimizing proliferation risks by conducting research and development of advanced fuel cycles, including modified open and closed cycles. The safe management and disposition of used nuclear fuel and/or nuclear waste is a fundamental aspect of any nuclear fuel cycle. Yet, the routine disposal of used nuclear fuel and radioactive waste remains problematic. Advanced fuel cycles will generate different quantities and forms of waste than the current LWR fleet. This study analyzes the quantities and characteristics of potential waste forms including differing waste matrices, as a function of a variety of potential fuel cycle alternatives including: (1) Commercial UNF generated by uranium fuel light water reactors (LWR). Four once through fuel cycles analyzed in this study differ by varying the assumed expansion/contraction of nuclear power in the U.S; (2) Four alternative LWR used fuel recycling processes analyzed differ in the reprocessing method (aqueous vs. electro-chemical), complexity (Pu only or full transuranic (TRU) recovery) and waste forms generated; (3) Used Mixed Oxide (MOX) fuel derived from the recovered Pu utilizing a single reactor pass; and (4) Potential waste forms generated by the reprocessing of fuels derived from recovered TRU utilizing multiple reactor passes.

  13. FUEL CYCLE POTENTIAL WASTE FOR DISPOSITION

    SciTech Connect (OSTI)

    Carter, J.

    2011-01-03

    The United States (U.S.) currently utilizes a once-through fuel cycle where used nuclear fuel (UNF) is stored on-site in either wet pools or in dry storage systems with ultimate disposal in a deep mined geologic repository envisioned. Within the Department of Energy's (DOE) Office of Nuclear Energy (DOE-NE), the Fuel Cycle Research and Development Program (FCR&D) develops options to the current commercial fuel cycle management strategy to enable the safe, secure, economic, and sustainable expansion of nuclear energy while minimizing proliferation risks by conducting research and development of advanced fuel cycles, including modified open and closed cycles. The safe management and disposition of used nuclear fuel and/or nuclear waste is a fundamental aspect of any nuclear fuel cycle. Yet, the routine disposal of used nuclear fuel and radioactive waste remains problematic. Advanced fuel cycles will generate different quantities and forms of waste than the current LWR fleet. This study analyzes the quantities and characteristics of potential waste forms including differing waste matrices, as a function of a variety of potential fuel cycle alternatives including: (1) Commercial UNF generated by uranium fuel light water reactors (LWR). Four once through fuel cycles analyzed in this study differ by varying the assumed expansion/contraction of nuclear power in the U.S. (2) Four alternative LWR used fuel recycling processes analyzed differ in the reprocessing method (aqueous vs. electro-chemical), complexity (Pu only or full transuranic (TRU) recovery) and waste forms generated. (3) Used Mixed Oxide (MOX) fuel derived from the recovered Pu utilizing a single reactor pass. (4) Potential waste forms generated by the reprocessing of fuels derived from recovered TRU utilizing multiple reactor passes.

  14. Modeling analyses of the effects of changes in nitrogen oxides emissions from the electric power sector on ozone levels in the eastern United States

    SciTech Connect (OSTI)

    Edith Gego; Alice Gilliland; James Godowitch

    2008-04-15

    In this paper, we examine the changes in ambient ozone concentrations simulated by the Community Multiscale Air Quality (CMAQ) model for summer 2002 under three different nitrogen oxides (NOx) emission scenarios. Two emission scenarios represent best estimates of 2002 and 2004 emissions; they allow assessment of the impact of the NOx emissions reductions imposed on the utility sector by the NOx State Implementation Plan (SIP) Call. The third scenario represents a hypothetical rendering of what NOx emissions would have been in 2002 if no emission controls had been imposed on the utility sector. Examination of the modeled median and 95th percentile daily maximum 8-hr average ozone concentrations reveals that median ozone levels estimated for the 2004 emission scenario were less than those modeled for 2002 in the region most affected by the NOx SIP Call. Comparison of the 'no-control' with the '2002' scenario revealed that ozone concentrations would have been much higher in much of the eastern United States if the utility sector had not implemented NOx emission controls; exceptions occurred in the immediate vicinity of major point sources where increased NO titration tends to lower ozone levels. 13 refs., 8 figs., 2 tabs.

  15. United States

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

    E-T Global Energy, LLC OE Docket No. EA-381 Order Authorizing Electricity Exports to Mexico Order No. EA-381 June 10, 2011 I. BACKGROUND E-T Global Energy, LLC Order No. EA-381 Exports of electricity from the United States to a foreign country are regulated by the Department of Energy (DOE) pursuant to sections 301(b) and 402(f) of the Department ofEnergy Organization Act (42 U.S.C. 7151(b), 7172(f)) and require authorization under section 202(e) ofthe Federal Power Act (FPA) (16 U.S.C.824a(e))

  16. United States

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

    Tenaslta Power Services Co. OE Docket No. EA-243-A Order Authorizing Electricity Exports to Canada Order No. EA-243-A March 1,2007 Tenaska Power Services Co. Order No. EA-243-A I. BACKGROUND Exports of elcctricity from the United States to a foreign country are regulated by the Department of Energy (DOE) pursuant to sections 30 I(b) and 402(f) of the Departrncnt of' Energy Organizatio~l Act (42 U, S.C. 7 15 1 (b), 7 1 72Cf)) and rcquirc authorization under section 202(e) of the Federal Power Act

  17. United States

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

    TexMex Energy, LLC OE Docket No. EA-294-A Order Authorizing Electricity Exports to Mexico Order No. EA-294-A February 22, 2007 TexMex Energy, LLC Order No. EA-294-A I. BACKGROUND Exports of electricity from the United States to a foreign count~y are regulated by the Department of Energy (DOE) pursuant to sections 301(b) and 402(f) of the Department of Energy Organization Act (42 U.S.C. 7 15 1 (b), 71 72(f)) and require authorization under section 202(e) of the Federal Power Act (FPA) (16

  18. United States

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

    CSW Power Marketing OE Docket No. EA-3 1 8 Order Authorizing Electricity Exports to Mexico Order No. EA-3 18 February 22,2007 CSW Power Marketing Order No. EA-318 I. BACKGROUND Exports of electricity from the United States to a foreign country are regulated by the Department of Energy (DOE) pursuant to sections 30l(b) and 402(f) of the Department of Energy Organization Act (42 U.S.C. 7 1 5 1 (b), 7 1 72(f)) and require authorization under section 202(e) of the Federal Power Act (FPA) (16

  19. United States

    Office of Environmental Management (EM)

    E-T Global Energy, LLC OE Docket No. EA-381 Order Authorizing Electricity Exports to Mexico Order No. EA-381 June 10, 2011 I. BACKGROUND E-T Global Energy, LLC Order No. EA-381 Exports of electricity from the United States to a foreign country are regulated by the Department of Energy (DOE) pursuant to sections 301(b) and 402(f) of the Department ofEnergy Organization Act (42 U.S.C. 7151(b), 7172(f)) and require authorization under section 202(e) ofthe Federal Power Act (FPA) (16 U.S.C.824a(e))

  20. Terrestrial Carbon Cycle

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

    cycle Terrestrial Carbon Cycle "Only about half of the CO2 released into the atmosphere by human activities currently resides in the atmosphere, the rest absorbed on land and in the oceans. The period over which the carbon will be sequestered is unclear, and the efficiency of future sinks is unknown." US Carbon Cycle Research Plan "We" desire to be able to predict the future spatial and temporal distribution of sources and sinks of atmospheric CO2 and their interaction

  1. Power Plant Cycling Costs

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

    ... Intertek APTECH has organized the cycling cost data in consultation with NREL and WECC by the following eight generator plant types: 1. Small coal-fired sub-critical steam (35-299 ...

  2. Forest Carbon Cycle

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

    forest carbon cycle Forest Carbon Cycle Terrestrial carbon stocks above- and belowground (in humus and litter layers, woody debris, and mineral soil) are not only sensitive to physical environmental controls (e.g., temperature, precipitation, soil moisture) but also to land use history/management, disturbance, "quality" of carbon input (a reflection of plant carbon allocation and species controls), and the microbial community. The relative importance of these controls on soil carbon

  3. Wetland (peat) Carbon Cycle

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

    wetland peat carbon cycle Wetland (peat) Carbon Cycle Methane (CH4) is an important greenhouse gas, twenty times more potent than CO2, but atmospheric concentrations of CH4 under future climate change are uncertain. This is in part because many climate-sensitive ecosystems release both CH4 and carbon dioxide (CO2) and it is unknown how these systems will partition future releases of carbon to the atmosphere. Ecosystem observations of CH4 emissions lack mechanistic links to the processes that

  4. Fast Reactor Fuel Cycle Cost Estimates for Advanced Fuel Cycle...

    Office of Scientific and Technical Information (OSTI)

    Title: Fast Reactor Fuel Cycle Cost Estimates for Advanced Fuel Cycle Studies Authors: Harrison, Thomas J 1 + Show Author Affiliations ORNL ORNL Publication Date: 2013-01-01 ...

  5. Truck Duty Cycle and Performance Data Collection and Analysis...

    Broader source: Energy.gov (indexed) [DOE]

    Collection and Analysis Program Heavy Duty & Medium Duty Drive Cycle Data Collection for Modeling Expansion Roadmap and Technical White Papers for 21st Century Truck Partnership

  6. NETL - Petroleum-Based Fuels Life Cycle Greenhouse Gas Analysis...

    Open Energy Info (EERE)

    search Tool Summary LAUNCH TOOL Name: NETL - Petroleum-Based Fuels Life Cycle Greenhouse Gas Analysis 2005 Baseline Model AgencyCompany Organization: National Energy Technology...

  7. Integrating Human Indoor Air Pollutant Exposure within Life Cycle Impact Assessment

    SciTech Connect (OSTI)

    Hellweg, Stefanie; Demou, Evangelia; Bruzzi, Raffaella; Meijer, Arjen; Rosenbaum, Ralph K.; Huijbregts, Mark A.J.; McKone, Thomas E.

    2008-12-21

    Neglecting health effects from indoor pollutant emissions and exposure, as currently done in Life Cycle Assessment (LCA), may result in product or process optimizations at the expense of workers? or consumers? health. To close this gap, methods for considering indoor exposure to chemicals are needed to complement the methods for outdoor human exposure assessment already in use. This paper summarizes the work of an international expert group on the integration of human indoor and outdoor exposure in LCA, within the UNEP/SETAC Life Cycle Initiative. A new methodological framework is proposed for a general procedure to include human-health effects from indoor exposure in LCA. Exposure models from occupational hygiene and household indoor air quality studies and practices are critically reviewed and recommendations are provided on the appropriateness of various model alternatives in the context of LCA. A single-compartment box model is recommended for use as a default in LCA, enabling one to screen occupational and household exposures consistent with the existing models to assess outdoor emission in a multimedia environment. An initial set of model parameter values was collected. The comparison between indoor and outdoor human exposure per unit of emission shows that for many pollutants, intake per unit of indoor emission may be several orders of magnitude higher than for outdoor emissions. It is concluded that indoor exposure should be routinely addressed within LCA.

  8. Watts Bar Operating Cycles Simulated...

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

    poison types and included TPBAR LTAs. Cycle 3 began the use of annular blanket pellets for the fuel rods containing IFBA. Cycle 4 implemented a 1.4% mid-cycle power ...

  9. Assessment for advanced fuel cycle options in CANDU

    SciTech Connect (OSTI)

    Morreale, A.C.; Luxat, J.C.; Friedlander, Y.

    2013-07-01

    The possible options for advanced fuel cycles in CANDU reactors including actinide burning options and thorium cycles were explored and are feasible options to increase the efficiency of uranium utilization and help close the fuel cycle. The actinide burning TRUMOX approach uses a mixed oxide fuel of reprocessed transuranic actinides from PWR spent fuel blended with natural uranium in the CANDU-900 reactor. This system reduced actinide content by 35% and decreased natural uranium consumption by 24% over a PWR once through cycle. The thorium cycles evaluated used two CANDU-900 units, a generator and a burner unit along with a driver fuel feedstock. The driver fuels included plutonium reprocessed from PWR, from CANDU and low enriched uranium (LEU). All three cycles were effective options and reduced natural uranium consumption over a PWR once through cycle. The LEU driven system saw the largest reduction with a 94% savings while the plutonium driven cycles achieved 75% savings for PWR and 87% for CANDU. The high neutron economy, online fuelling and flexible compact fuel make the CANDU system an ideal reactor platform for many advanced fuel cycles.

  10. Advanced Fuel Cycle Cost Basis

    SciTech Connect (OSTI)

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2008-03-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  11. Advanced Fuel Cycle Cost Basis

    SciTech Connect (OSTI)

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert; E. Schneider

    2009-12-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 25 cost modules—23 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, transuranic, and high-level waste.

  12. Advanced Fuel Cycle Cost Basis

    SciTech Connect (OSTI)

    D. E. Shropshire; K. A. Williams; W. B. Boore; J. D. Smith; B. W. Dixon; M. Dunzik-Gougar; R. D. Adams; D. Gombert

    2007-04-01

    This report, commissioned by the U.S. Department of Energy (DOE), provides a comprehensive set of cost data supporting a cost analysis for the relative economic comparison of options for use in the Advanced Fuel Cycle Initiative (AFCI) Program. The report describes the AFCI cost basis development process, reference information on AFCI cost modules, a procedure for estimating fuel cycle costs, economic evaluation guidelines, and a discussion on the integration of cost data into economic computer models. This report contains reference cost data for 26 cost modules—24 fuel cycle cost modules and 2 reactor modules. The cost modules were developed in the areas of natural uranium mining and milling, conversion, enrichment, depleted uranium disposition, fuel fabrication, interim spent fuel storage, reprocessing, waste conditioning, spent nuclear fuel (SNF) packaging, long-term monitored retrievable storage, near surface disposal of low-level waste (LLW), geologic repository and other disposal concepts, and transportation processes for nuclear fuel, LLW, SNF, and high-level waste.

  13. Helium process cycle

    DOE Patents [OSTI]

    Ganni, Venkatarao

    2008-08-12

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  14. Helium process cycle

    DOE Patents [OSTI]

    Ganni, Venkatarao

    2007-10-09

    A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

  15. Termination unit

    DOE Patents [OSTI]

    Traeholt, Chresten [Frederiksberg, DK; Willen, Dag [Klagshamn, SE; Roden, Mark [Newnan, GA; Tolbert, Jerry C [Carrollton, GA; Lindsay, David [Carrollton, GA; Fisher, Paul W [Heiskell, TN; Nielsen, Carsten Thidemann [Jaegerspris, DK

    2014-01-07

    This invention relates to a termination unit comprising an end-section of a cable. The end section of the cable defines a central longitudinal axis and comprising end-parts of N electrical phases, an end-part of a neutral conductor and a surrounding thermally insulation envelope adapted to comprising a cooling fluid. The end-parts of the N electrical phases and the end-part of the neutral conductor each comprising at least one electrical conductor and being arranged in the cable concentrically around a core former with a phase 1 located relatively innermost, and phase N relatively outermost in the cable, phase N being surrounded by the neutral conductor, electrical insulation being arrange between neighboring electrical phases and between phase N and the neutral conductor, and wherein the end-parts of the neutral conductor and the electrical phases each comprise a contacting surface electrically connected to at least one branch current lead to provide an electrical connection: The contacting surfaces each having a longitudinal extension, and being located sequentially along the longitudinal extension of the end-section of the cable. The branch current leads being individually insulated from said thermally insulation envelope by individual electrical insulators.

  16. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

    Swift, Gregory W.; Kotsubo, Vincent Y.

    1992-01-01

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

  17. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

    Swift, G.W.; Kotsubo, V.Y.

    1992-12-22

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He-[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K. 12 figs.

  18. Fuel Cell Power Model Elucidates Life-Cycle Costs for Fuel Cell-Based Combined Heat, Hydrogen, and Power (CHHP) Production Systems (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-11-01

    This fact sheet describes NREL's accomplishments in accurately modeling costs for fuel cell-based combined heat, hydrogen, and power systems. Work was performed by NREL's Hydrogen Technologies and Systems Center.

  19. " Million Housing Units, Final...

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

    ... Vacant housing units, seasonal units, second homes, military housing, and group quarters are excluded. 2Use of central air conditioning equipment for another housing unit also ...

  20. " Million Housing Units, Final...

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

    ... Vacant housing units, seasonal units, second homes, military housing, and group quarters are excluded. 2Housing units are classified as urban or rural using definitions created by ...

  1. " Million Housing Units, Final...

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

    ... Vacant housing units, seasonal units, second homes, military housing, and group quarters are excluded. 2Use of heating equipment for another housing unit also includes the use of ...

  2. " Million Housing Units, Final"

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

    ... Vacant housing units, seasonal units, second homes, military housing, and group quarters are excluded. 2Use of central air conditioning equipment for another housing unit also ...

  3. Cycles in fossil diversity

    SciTech Connect (OSTI)

    Rohde, Robert A.; Muller, Richard A.

    2004-10-20

    It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

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

    SciTech Connect (OSTI)

    John McCord

    2007-05-01

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

  5. " Million Housing Units, Final...

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

    Water Heating in U.S. Homes, by Housing Unit Type, 2009" " Million Housing Units, Final" ... Units","5 or More Units","Mobile Homes" "Water Heating" "Total Homes",113.6,71.8,6.7,9,19...

  6. Fuel-Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with...

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

    Fuel-Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model Fuel-Cycle Analysis of Hydrogen-Powered Fuel-Cell Systems with the GREET Model This presentation by ...

  7. Life-Cycle Assessment of Pyrolysis Bio-Oil Production*

    SciTech Connect (OSTI)

    Steele, Philip; Puettmann, Maureen E.; Penmetsa, Venkata Kanthi; Cooper, Jerome E.

    2012-07-01

    As part ofthe Consortium for Research on Renewable Industrial Materials' Phase I life-cycle assessments ofbiofuels, lifecycle inventory burdens from the production of bio-oil were developed and compared with measures for residual fuel oil. Bio-oil feedstock was produced using whole southern pine (Pinus taeda) trees, chipped, and converted into bio-oil by fast pyrolysis. Input parameters and mass and energy balances were derived with Aspen. Mass and energy balances were input to SimaPro to determine the environmental performance of bio-oil compared with residual fuel oil as a heating fuel. Equivalent functional units of 1 MJ were used for demonstrating environmental preference in impact categories, such as fossil fuel use and global warming potential. Results showed near carbon neutrality of the bio-oil. Substituting bio-oil for residual fuel oil, based on the relative carbon emissions of the two fuels, estimated a reduction in CO2 emissions by 0.075 kg CO2 per MJ of fuel combustion or a 70 percent reduction in emission over residual fuel oil. The bio-oil production life-cycle stage consumed 92 percent of the total cradle-to-grave energy requirements, while feedstock collection, preparation, and transportation consumed 4 percent each. This model provides a framework to better understand the major factors affecting greenhouse gas emissions related to bio-oil production and conversion to boiler fuel during fast pyrolysis.

  8. Aspen Process Flowsheet Simulation Model of a Battelle Biomass-Based Gasification, Fischer-Tropsch Liquefaction and Combined-Cycle Power Plant

    SciTech Connect (OSTI)

    1998-10-30

    This study was done to support the research and development program of the National Renewable Energy Laboratory (NREL) in the thermochemical conversion of biomass to liquid transportation fuels using current state-of-the-art technology. The Mitretek study investigated the use of two biomass gasifiers; the RENUGAS gasifier being developed by the Institute of Gas Technology, and the indirectly heated gasifier being developed by Battelle Columbus. The Battelle Memorial Institute of Columbus, Ohio indirectly heated biomass gasifier was selected for this model development because the syngas produced by it is better suited for Fischer-Tropsch synthesis with an iron-based catalyst for which a large amount of experimental data are available. Bechtel with Amoco as a subcontractor developed a conceptual baseline design and several alternative designs for indirect coal liquefaction facilities. In addition, ASPEN Plus process flowsheet simulation models were developed for each of designs. These models were used to perform several parametric studies to investigate various alternatives for improving the economics of indirect coal liquefaction.

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

    SciTech Connect (OSTI)

    Nathan Bryant

    2008-05-01

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

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

    SciTech Connect (OSTI)

    Nathan Bryant

    2008-05-01

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