Final Report - Composite Fermion Approach to Strongly Interacting Quasi Two Dimensional Electron Gas Systems (open access)

Final Report - Composite Fermion Approach to Strongly Interacting Quasi Two Dimensional Electron Gas Systems

Work related to this project introduced the idea of an “effective monopole strength” Q* that acted as the effective angular momentum of the lowest shell of composite Fermions (CF). This allowed us to predict the angular momentum of the lowest band of energy states for any value of the applied magnetic field simply by determining N{sub QP} the number of quasielectrons (QE) or quasiholes (QH) in a partially filled CF shell and adding angular momenta of the N{sub QP} Fermions excitations. The approach reported treated the filled CF level as a “vacuum state” which could support QE and QH excitations. Numerical diagonalization of small systems allowed us to determine the angular momenta, the energy, and the pair interaction energies of these elementary excitations. The spectra of low energy states could then be evaluated in a Fermi liquid‐like picture, treating the much smaller number of quasiparticles and their interactions instead of the larger system of N electrons with Coulomb interactions.
Date: November 30, 2009
Creator: Quinn, John
Object Type: Report
System: The UNT Digital Library
Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions (open access)

Ground motion modeling of Hayward fault scenario earthquakes II:Simulation of long-period and broadband ground motions

We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the …
Date: November 4, 2009
Creator: Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D et al.
Object Type: Article
System: The UNT Digital Library
Extended model for Richtmyer-Meshkov mix (open access)

Extended model for Richtmyer-Meshkov mix

We examine four Richtmyer-Meshkov (RM) experiments on shock-generated turbulent mix and find them to be in good agreement with our earlier simple model in which the growth rate h of the mixing layer following a shock or reshock is constant and given by 2{alpha}A{Delta}v, independent of initial conditions h{sub 0}. Here A is the Atwood number ({rho}{sub B}-{rho}{sub A})/({rho}{sub B} + {rho}{sub A}), {rho}{sub A,B} are the densities of the two fluids, {Delta}V is the jump in velocity induced by the shock or reshock, and {alpha} is the constant measured in Rayleigh-Taylor (RT) experiments: {alpha}{sup bubble} {approx} 0.05-0.07, {alpha}{sup spike} {approx} (1.8-2.5){alpha}{sup bubble} for A {approx} 0.7-1.0. In the extended model the growth rate beings to day after a time t*, when h = h*, slowing down from h = h{sub 0} + 2{alpha}A{Delta}vt to h {approx} t{sup {theta}} behavior, with {theta}{sup bubble} {approx} 0.25 and {theta}{sup spike} {approx} 0.36 for A {approx} 0.7. They ascribe this change-over to loss of memory of the direction of the shock or reshock, signaling transition from highly directional to isotropic turbulence. In the simplest extension of the model h*/h{sub 0} is independent of {Delta}v and depends only on A. They find that h*/h{sub …
Date: November 18, 2009
Creator: Mikaelian, K O
Object Type: Article
System: The UNT Digital Library
Validation of a Monte Carlo Based Depletion Methodology Using HFIR Post-Irradiation Measurements (open access)

Validation of a Monte Carlo Based Depletion Methodology Using HFIR Post-Irradiation Measurements

Post-irradiation uranium isotopic atomic densities within the core of the High Flux Isotope Reactor (HFIR) were calculated and compared to uranium mass spectrographic data measured in the late 1960s and early 70s [1]. This study was performed in order to validate a Monte Carlo based depletion methodology for calculating the burn-up dependent nuclide inventory, specifically the post-irradiation uranium
Date: November 1, 2009
Creator: Chandler, David; Maldonado, G Ivan & Primm, Trent
Object Type: Report
System: The UNT Digital Library
Simulation-based assessment of the energy savings benefits of integrated control in office buildings (open access)

Simulation-based assessment of the energy savings benefits of integrated control in office buildings

The purpose of this study is to use existing simulation tools to quantify the energy savings benefits of integrated control in office buildings. An EnergyPlus medium office benchmark simulation model (V1.0_3.0) developed by the Department of Energy (DOE) was used as a baseline model for this study. The baseline model was modified to examine the energy savings benefits of three possible control strategies compared to a benchmark case across 16 DOE climate zones. Two controllable subsystems were examined: (1) dimming of electric lighting, and (2) controllable window transmission. Simulation cases were run in EnergyPlus V3.0.0 for building window-to-wall ratios (WWR) of 33percent and 66percent. All three strategies employed electric lighting dimming resulting in lighting energy savings in building perimeter zones ranging from 64percent to 84percent. Integrated control of electric lighting and window transmission resulted in heating, ventilation, and air conditioning (HVAC) energy savings ranging from ?1percent to 40percent. Control of electric lighting and window transmission with HVAC integration (seasonal schedule of window transmission control) resulted in HVAC energy savings ranging from 3percent to 43percent. HVAC energy savings decreased moving from warm climates to cold climates and increased when moving from humid, to dry, to marine climates.
Date: November 1, 2009
Creator: Hong, T. & Shen, E.
Object Type: Article
System: The UNT Digital Library
Membrane-Associated Methane Monooygenase from Type X and Type I Methanotrophs (open access)

Membrane-Associated Methane Monooygenase from Type X and Type I Methanotrophs

Membrane-Associated Methane Monooxygenases from Type X and Type I Methanotrophs A.A. DiSirito and W.E. Antholine Project Number: DE-FG02-00ER15446 Final project report.
Date: November 30, 2009
Creator: Antholine, William E. & DiSpirito, Alan A.
Object Type: Report
System: The UNT Digital Library
Plasma Amplifier contribution for FY09 LDRD Annual Report (open access)

Plasma Amplifier contribution for FY09 LDRD Annual Report

None
Date: November 16, 2009
Creator: Kirkwood, R
Object Type: Report
System: The UNT Digital Library
Strong stabilization of the Rayleigh-Taylor instability by material strength at Mbar pressures (open access)

Strong stabilization of the Rayleigh-Taylor instability by material strength at Mbar pressures

Experimental results showing significant reductions from classical in the Rayleigh-Taylor (RT) instability growth rate due to high pressure effective lattice viscosity are presented. Using a laser created ramped drive, vanadium samples are compressed and accelerated quasi-isentropically at {approx}1 Mbar pressures, while maintaining the sample in the solid-state. Comparisons with simulations and theory indicate that the high pressure, high strain rate conditions trigger a phonon drag mechanism, resulting in the observed high effective lattice viscosity and strong stabilization of the RT instability.
Date: November 19, 2009
Creator: Park, H. S.; Lorenz, K. T.; Cavallo, R. M.; Pollaine, S. M.; Prisbrey, S. T.; Rudd, R. E. et al.
Object Type: Article
System: The UNT Digital Library
Facilities Condition and Hazards Assessment for Materials and Fuel Complex Facilities MFC-799, 799A, and 770C (open access)

Facilities Condition and Hazards Assessment for Materials and Fuel Complex Facilities MFC-799, 799A, and 770C

The Materials & Fuel Complex (MFC) facilities 799 Sodium Processing Facility (a single building consisting of two areas: the Sodium Process Area (SPA) and the Carbonate Process Area (CPA), 799A Caustic Storage Area, and 770C Nuclear Calibration Laboratory have been declared excess to future Department of Energy mission requirements. Transfer of these facilities from Nuclear Energy to Environmental Management, and an associated schedule for doing so, have been agreed upon by the two offices. The prerequisites for this transfer to occur are the removal of nonexcess materials and chemical inventory, deinventory of the calibration source in MFC-770C, and the rerouting and/or isolation of utility and service systems. This report provides a description of the current physical condition and any hazards (material, chemical, nuclear or occupational) that may be associated with past operations of these facilities. This information will document conditions at time of transfer of the facilities from Nuclear Energy to Environmental Management and serve as the basis for disposition planning. The process used in obtaining this information included document searches, interviews and facility walk-downs. A copy of the facility walk-down checklist is included in this report as Appendix A. MFC-799/799A/770C are all structurally sound and associated hazardous or potentially …
Date: November 1, 2009
Creator: Mecham, Gary & Konoyer, Don
Object Type: Report
System: The UNT Digital Library
UV laser ablation of parylene films from gold substrates (open access)

UV laser ablation of parylene films from gold substrates

Parylene films, coating gold substrates, were removed by laser ablation using 248 nm light from an excimer laser. Each sample was processed by a different number of pulses in one of three different environments: air at atmospheric pressure, nitrogen at atmospheric pressure, and vacuum. The laser-induced craters were analyzed by optical microscopy and x-ray photoelectron spectroscopy. Multi-pulse ablation thresholds of gold and parylene were estimated.
Date: November 19, 2009
Creator: Musaev, O. R.; Scott, P.; Wrobel, J. M. & Kruger, M. B.
Object Type: Article
System: The UNT Digital Library
Gasbuggy, New Mexico, Hydrologic and Natural Gas Sampling and Analysis Results for 2009 (open access)

Gasbuggy, New Mexico, Hydrologic and Natural Gas Sampling and Analysis Results for 2009

The U.S. Department of Energy (DOE) Office of Legacy Management conducted hydrologic and natural gas sampling for the Gasbuggy, New Mexico, site on June 16, and 17, 2009. Hydrologic sampling consists of collecting water samples from water wells and surface water locations. Natural gas sampling consists of collecting both gas samples and samples of produced water from gas production wells. The water well samples were analyzed for gamma-emitting radionuclides and tritium. Surface water samples were analyzed for tritium. Water samples from gas production wells were analyzed for gamma-emitting radionuclides, gross alpha, gross beta, and tritium. Natural gas samples were analyzed for tritium and carbon-14. Water samples were analyzed by ALS Laboratory Group in Fort Collins, Colorado, and natural gas samples were analyzed by Isotech Laboratories in Champaign, Illinois. Concentrations of tritium and gamma-emitting radionuclides in water samples collected in the vicinity of the Gasbuggy site continue to demonstrate that the sample locations have not been impacted by detonation-related contaminants. Results from the sampling of natural gas from producing wells demonstrate that the gas wells nearest the Gasbuggy site are not currently impacted by detonation-related contaminants. Annual sampling of the gas production wells nearest the Gasbuggy site for gas and produced …
Date: November 1, 2009
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Scintillation Properties of Eu2+-Activated Barium Fluoroiodide (open access)

Scintillation Properties of Eu2+-Activated Barium Fluoroiodide

The scintillation properties of powders and single-crystals of BaFI doped with Eu2+ are presented. Single crystals were grown by the vertical Bridgman technique. Under optical and X-ray excitation, the samples exhibit a narrow E2+ 5d-4f transition emission centered at 405 nm. The scintillation light output is estimated to be 55,000+-5,000 photons/MeV at 662 keV with 85percent of the light decaying within 600 ns. An energyresolution of 8.5percent full width at half maximum (FWHM) has been achieved using this scintillator for 662 keV excitation (137Cs source) at room temperature.
Date: November 18, 2009
Creator: Gundiah, Gautam; Bourret-Courchesne, Edith; Bizarri, Gregory; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew et al.
Object Type: Article
System: The UNT Digital Library
MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_ (open access)

MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).
Date: November 1, 2009
Creator: Moore, G. A.; Rice, F. J.; Woolstenhulme, N. E.; Jue, J-F.; Park, B. H.; Steffler, S. E. et al.
Object Type: Article
System: The UNT Digital Library
High Performance Green LEDs by Homoepitaxial (open access)

High Performance Green LEDs by Homoepitaxial

This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.
Date: November 22, 2009
Creator: Wetzel, Christian & Schubert, E Fred
Object Type: Report
System: The UNT Digital Library
Heat of Combustion of Tantalum-Tungsten Oxide Thermite Composites (open access)

Heat of Combustion of Tantalum-Tungsten Oxide Thermite Composites

None
Date: November 12, 2009
Creator: Cervantes, O; Kuntz, J; Gash, A & Munir, Z
Object Type: Article
System: The UNT Digital Library
A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES (open access)

A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as …
Date: November 1, 2009
Creator: Blau, Peter Julian
Object Type: Report
System: The UNT Digital Library
Natural Areas Analysis and Evaluation: Oak Ridge Reservation (open access)

Natural Areas Analysis and Evaluation: Oak Ridge Reservation

EXECUTIVE SUMMARY The Oak Ridge Reservation, encompassing 33,639 acres in the Valley and Ridge Physiographic Province of East Tennessee, has long been known for its unfragmented forests and high biodiversity. Many areas on the Reservation have been recognized as important natural areas, but no comprehensive treatment has been performed to evaluate the relative significance and importance of these areas compared to each other. The present study was conducted to develop a set of guidelines for evaluating the natural value of specific areas, to evaluate all the terrestrial areas that are currently delineated, and to rank all areas according to their relative biodiversity importance. All available data, reports and site-specific information relevant to Reservation lands, including Tennessee Division of Natural Areas database information, were evaluated and field work was conducted. Methodologies and criteria for assessment and evaluation of areas were developed; categories of criteria were devised; and a ranking system for evaluation of natural areas was produced. There were 70 areas evaluated during the study. The system is flexible, dynamic and easily revised to reflect updated and new information and interpretations. Eight categories of evaluation factors were established and used to characterize each site. These were the following: size of area, …
Date: November 2009
Creator: Baranski, Micahel J.
Object Type: Report
System: The UNT Digital Library
Critical Evaluation of the ISCCP Simulator Using Ground-Based Remote Sensing Data (open access)

Critical Evaluation of the ISCCP Simulator Using Ground-Based Remote Sensing Data

Given the known shortcomings in representing clouds in Global Climate Models (GCM) comparisons with observations are critical. The International Satellite Cloud Climatology Project (ISCCP) diagnostic products provide global descriptions of cloud top pressure and column optical depth that extends over multiple decades. The necessary limitations of the ISCCP retrieval algorithm require that before comparisons can be made between model output and ISCCP results the model output must be modified to simulate what ISCCP would diagnose under the simulated circumstances. We evaluate one component of the so-called ISCCP simulator in this study by comparing ISCCP and a similar algorithm with various long-term statistics derived from the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility ground-based remote sensors. We find that were a model to simulate the cloud radiative profile with the same accuracy as can be derived from the ARM data, then the likelihood of that occurrence being placed in the same cloud top pressure and optical depth bin as ISCCP of the 9 bins that have become standard ranges from 30% to 70% depending on optical depth. While the ISCCP simulator improved the agreement of cloud-top pressure between ground-based remote sensors and satellite observations, we find minor …
Date: November 2, 2009
Creator: Mace, G. G.; Houser, S.; Benson, S.; Klein, S. A. & Min, Q.
Object Type: Article
System: The UNT Digital Library
Old-field Community, Climate and Atmospheric Manipulation (open access)

Old-field Community, Climate and Atmospheric Manipulation

We are in the process of finishing a number of laboratory, growth chamber and greenhouse projects, analyzing data, and writing papers. The projects reported addressed these subjects: How do climate and atmospheric changes alter aboveground plant biomass and community structure; Effects of multiple climate changes factors on plant community composition and diversity: what did we learn from a 5-year open-top chamber experiment using constructed old-field communities; Do atmospheric and climatic change factors interact to alter woody seedling emergence, establishment and productivity; Soil moisture surpasses elevated CO{sub 2} and temperature in importance as a control on soil carbon dynamics; How do climate and atmospheric changes alter belowground root and fungal biomass; How do climate and atmospheric changes alter soil microarthropod and microbial communities; How do climate and atmospheric changes alter belowground microbial function; Linking root litter diversity and microbial functioning at a micro scale under current and projected CO{sub 2} concentrations; Multifactor climate change effects on soil ecosystem functioning depend on concurrent changes in plant community composition; How do climate and atmospheric changes alter aboveground insect populations; How do climate and atmospheric changes alter festuca endophyte infection; How do climate and atmospheric changes soil carbon stabilization.
Date: November 1, 2009
Creator: Classen, Aimee
Object Type: Report
System: The UNT Digital Library
Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials (open access)

Synthesis of High-Purity alpha-and beta-PbO and Possible Applications to Synthesis and Processing of Other Lead Oxide Materials

The red, tetragonal form of lead oxide, alpha-PbO, litharge, and the yellow, orthorhombic form, beta-PbO, massicot, have been synthesized from lead(II) salts in aqueous media at elevated temperature. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the size, morphology, and crystallographic structural forms of the products. The role of impurities in the experimental synthesis of the materials and microstructural variations in the final products are described, and the implications of these observations with respect to the synthesis of different conducting lead oxides and other related materials are discussed.
Date: November 12, 2009
Creator: Perry, Dale L. & Wilkinson, T. J.
Object Type: Article
System: The UNT Digital Library
Extending the eigCG algorithm to non-symmetric linear systems with multiple right-hand sides (open access)

Extending the eigCG algorithm to non-symmetric linear systems with multiple right-hand sides

For Hermitian positive definite linear systems and eigenvalue problems, the eigCG algorithm is a memory efficient algorithm that solves the linear system and simultaneously computes some of its eigenvalues. The algorithm is based on the Conjugate-Gradient (CG) algorithm, however, it uses only a window of the vectors generated by the CG algorithm to compute approximate eigenvalues. The number and accuracy of the eigenvectors can be increased by solving more right-hand sides. For Hermitian systems with multiple right-hand sides, the computed eigenvectors can be used to speed up the solution of subsequent systems. The algorithm was tested on Lattice QCD problems by solving the normal equations and was shown to give large speed up factors and to remove the critical slowing down as we approach light quark masses. Here, an extension to the non-symmetric case based on the two-sided Lanczos algorithm is given. The new algorithm is tested on Lattice QCD problems and is shown to give promising results. We also study the removal of the critical slowing down and compare results with those of the eigCG algorithm. We also discuss the case when the system is gamma5-Hermitian.
Date: November 1, 2009
Creator: Abdou Abdel-Rehim, Kostas Orginos, Andreas Stathopoulos
Object Type: Article
System: The UNT Digital Library
Foam Transport in Porous Media - A Review (open access)

Foam Transport in Porous Media - A Review

Amendment solutions with or without surfactants have been used to remove contaminants from soil. However, it has drawbacks such that the amendment solution often mobilizes the plume, and its movement is controlled by gravity and preferential flow paths. Foam is an emulsion-like, two-phase system in which gas cells are dispersed in a liquid and separated by thin liquid films called lamellae. Potential advantages of using foams in sub-surface remediation include providing better control on the volume of fluids injected, uniformity of contact, and the ability to contain the migration of contaminant laden liquids. It is expected that foam can serve as a carrier of amendments for vadose zone remediation, e.g., at the Hanford Site. As part of the U.S. Department of Energy’s EM-20 program, a numerical simulation capability will be added to the Subsurface Transport Over Multiple Phases (STOMP) flow simulator. The primary purpose of this document is to review the modeling approaches of foam transport in porous media. However, as an aid to understanding the simulation approaches, some experiments under unsaturated conditions and the processes of foam transport are also reviewed. Foam may be formed when the surfactant concentration is above the critical micelle concentration. There are two main …
Date: November 11, 2009
Creator: Zhang, Z. F.; Freedman, Vicky L. & Zhong, Lirong
Object Type: Report
System: The UNT Digital Library
Integrated plan for LArTPC neutrino detectors in the US (open access)

Integrated plan for LArTPC neutrino detectors in the US

We present an integrated R&D plan aimed at demonstrating the ability to build a very large Liquid Argon Time Projection Chamber (LArTPC), on a scale suitable for use as a Far Detector for the LBNE neutrino oscillation experiment. This plan adopts current LArTPC R&D-related activities and proposes new ones to address questions that go beyond those being answered by the current efforts. We have employed a risk evaluation strategy to identify questions that can be answered (or risks that can be mitigated) through one or more R&D steps. In summary form, the plan consists of the following pre-existing components: (1) The Materials Test Stand program, now in operation at Fermilab, addressing questions pertaining to maintenance of argon purity; (2) Existing electronics test stands at FNAL and BNL; (3) The Liquid Argon Purity Demonstrator (LAPD) now being assembled at Fermilab; (4) The ArgoNeuT prototype LArTPC, now running in the NuMI beam; (5) The MicroBooNE experiment, proposed as a physics experiment that will advance our understanding of the LArTPC technology, now completing its conceptual design phase; (6) A software development effort that is well integrated across present and planned LArTPC detectors. We are proposing to add to these efforts the following: (1) …
Date: November 1, 2009
Creator: Baller, B. & Fleming, B.
Object Type: Report
System: The UNT Digital Library
Criticality Benchmark Analysis of the HTTR Annular Startup Core Configurations (open access)

Criticality Benchmark Analysis of the HTTR Annular Startup Core Configurations

One of the high priority benchmarking activities for corroborating the Next Generation Nuclear Plant (NGNP) Project and Very High Temperature Reactor (VHTR) Program is evaluation of Japan's existing High Temperature Engineering Test Reactor (HTTR). The HTTR is a 30 MWt engineering test reactor utilizing graphite moderation, helium coolant, and prismatic TRISO fuel. A large amount of critical reactor physics data is available for validation efforts of High Temperature Gas-cooled Reactors (HTGRs). Previous international reactor physics benchmarking activities provided a collation of mixed results that inaccurately predicted actual experimental performance.1 Reevaluations were performed by the Japanese to reduce the discrepancy between actual and computationally-determined critical configurations.2-3 Current efforts at the Idaho National Laboratory (INL) involve development of reactor physics benchmark models in conjunction with the International Reactor Physics Experiment Evaluation Project (IRPhEP) for use with verification and validation methods in the VHTR Program. Annular cores demonstrate inherent safety characteristics that are of interest in developing future HTGRs.
Date: November 1, 2009
Creator: Bess, John D.
Object Type: Article
System: The UNT Digital Library