Agua Caliente Solar Feasibility and Pre-Development Study Final Report (open access)

Agua Caliente Solar Feasibility and Pre-Development Study Final Report

Evaluation of facility- and commercial-scale solar energy projects on the Agua Caliente Band of Cahuilla Indians Reservation in Palm Springs, CA. The Agua Caliente Band of Cahuilla Indians (ACBCI) conducted a feasibility and pre-development study of potential solar projects on its lands in southern California. As described below, this study as a logical and necessary next step for ACBCI. Support for solar project development in California, provided through the statewide California Solar Initiative (CSI), its Renewable Portfolio Standard and Feed-in Tariff Program, and recently announced Reverse Auction Mechanism, provide unprecedented support and incentives that can be utilized by customers of California's investor-owned utilities. Department of Energy (DOE) Tribal Energy Program funding allowed ACBCI to complete its next logical step to implement its Strategic Energy Plan, consistent with its energy and sustainability goals.
Date: April 26, 2011
Creator: Carolyn T. Stewart, Managing Partner & Partners, Red Mountain Energy
Object Type: Report
System: The UNT Digital Library
Analysis of Energy, Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate (open access)

Analysis of Energy, Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate

It has been widely recognized that the energy saving benefits of GSHP systems are best realized in the northern and central regions where heating needs are dominant or both heating and cooling loads are comparable. For hot and humid climate such as in the states of FL, LA, TX, southern AL, MS, GA, NC and SC, buildings have much larger cooling needs than heating needs. The Hybrid GSHP (HGSHP) systems therefore have been developed and installed in some locations of those states, which use additional heat sinks (such as cooling tower, domestic water heating systems) to reject excess heat. Despite the development of HGSHP the comprehensive analysis of their benefits and barriers for wide application has been limited and often yields non-conclusive results. In general, GSHP/HGSHP systems often have higher initial costs than conventional systems making short-term economics unattractive. Addressing these technical and financial barriers call for additional evaluation of innovative utility programs, incentives and delivery approaches. From scientific and technical point of view, the potential for wide applications of GSHP especially HGSHP in hot and humid climate is significant, especially towards building zero energy homes where the combined energy efficient GSHP and abundant solar energy production in hot climate …
Date: April 26, 2012
Creator: Tao, Yong X. & Zhu, Yimin
Object Type: Report
System: The UNT Digital Library
Beyond Mean-Field Calculation For Pairing Correlation (open access)

Beyond Mean-Field Calculation For Pairing Correlation

None
Date: April 26, 2012
Creator: Hupin, G & Lacroix, D
Object Type: Article
System: The UNT Digital Library
Biospecimen Reporting for Improved Study Quality (BRISQ) (open access)

Biospecimen Reporting for Improved Study Quality (BRISQ)

Human biospecimens are subject to a number of different collection, processing, and storage factors that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research utilizing human tissues it is critical that information regarding the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality (BRISQ) recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The BRISQ guidelines are proposed as an important and timely resource tool to strengthen communication and publications around biospecimen-related research and help reassure patient contributors and the advocacy community that the contributions are valued and respected.
Date: April 26, 2011
Creator: Moore, Ph.D., Helen M.; Kelly Ph.D., Andrea; Jewell Ph.D., Scott D.; McShane Ph.D., Lisa M.; Clark M.D., Douglas P.; Greenspan M.D., Renata et al.
Object Type: Article
System: The UNT Digital Library
Categorization of Radioxenon (open access)

Categorization of Radioxenon

This report summarizes a study into some false positive issues in the use of radioxenon as a method to verify a clandestine nuclear weapons explosion. False positives arise due to similarities between the radioxenon signature generated in medical isotope production and that generated in a nuclear weapon explosion. This report also discusses how to categorize the radioxenon by levels of urgency for manual analysis and interpretation and recommends applying machine learning and time series analysis techniques in the automation of radioxenon characterization. The literature indicates that medical isotope production is a major contributor to atmospheric radioxenon and is the main source of confusion in determining the source of radioxenon. While radioxenon emissions from nuclear power plants can be distinguished from that from nuclear weapon explosions, emissions from medical isotope production generate signatures similar to certain nuclide ratios found in nuclear weapons explosions. Different techniques for analyzing nuclide concentrations and ratios as well as including other sensing modalities via sensor fusion are discussed.
Date: April 26, 2012
Creator: Keller, Paul E.
Object Type: Report
System: The UNT Digital Library
Effects and Mechanisms of Mechanical Activation on Hydrogen Sorption/ Desorption of Nanoscale Lithium Nitrides (open access)

Effects and Mechanisms of Mechanical Activation on Hydrogen Sorption/ Desorption of Nanoscale Lithium Nitrides

The objective of this project is to investigate and develop novel, mechanically activated, nanoscale Li3N-based and LiBH4-based materials that are able to store and release {approx}10 wt% hydrogen at temperatures near 100 C with a plateau hydrogen pressure of less than 10 bar. Four (4) material systems have been investigated in the course of this project in order to achieve the project objective. These 4 systems are (i) LiNH2+LiH, (ii) LiNH2+MgH2, (iii) LiBH4, and (iv) LiBH4+MgH2. The key findings we have obtained from these 4 systems are summarized below. *The thermodynamic driving forces for LiNH2+LiH and LiBH4 systems are not adequate to enable H2 release at temperatures < 100 C. *Hydrogen release in the solid state for all of the four systems is controlled by diffusion, and thus is a slow process. *LiNH2+MgH2 and LiBH4+MgH2 systems, although possessing proper thermodynamic driving forces to allow for H2 release at temperatures < 100 C, have sluggish reaction kinetics because of their diffusion-controlled rate-limiting steps. *Reducing particles to the nanometer length scale (< 50 nm) can improve the thermodynamic driving force to enable H2 release at near ambient temperature, while simultaneously enhancing the reaction kinetics as well as changing the diffusion-controlled rate-limiting step …
Date: April 26, 2012
Creator: Shaw, Leon, L.; Yang, Gary, Z.; Crosby, Kyle; Wwan, Xufei. Zhong, Yang; Markmaitree, Tippawan; Osborn, William et al.
Object Type: Report
System: The UNT Digital Library
EXAMINATION OF SHIPPING PACKAGES 9975-01968, 9975-04353 AND 9975-06870 (open access)

EXAMINATION OF SHIPPING PACKAGES 9975-01968, 9975-04353 AND 9975-06870

Three 9975 shipping packages were examined to investigate the non-conforming condition of an axial air gap greater than 1 inch. This condition typically indicates the presence of excess moisture in the fiberboard overpack, and may be accompanied by degradation in the fiberboard properties. In the case of these three packages, no excess moisture was present, and the fiberboard was not visibly degraded. However, the lower fiberboard assembly from 9975-06870 was separated into two pieces. The lead shield from 9975-04353 was heavily corroded, while the shield from 9975-01968 had very little corrosion. In the case of 9975-06870, the shield was covered by a stainless steel sleeve, and the condition of the lead was not observed. No other conditions of concern were observed in these three packages.
Date: April 26, 2010
Creator: Daugherty, W.
Object Type: Report
System: The UNT Digital Library
Fossil Fuel (CO2) Emission Verification Capability07-ERD-064Final Report (open access)

Fossil Fuel (CO2) Emission Verification Capability07-ERD-064Final Report

None
Date: April 26, 2011
Creator: Guilderson, T P; Cameron-Smith, P & Lucas, D D
Object Type: Report
System: The UNT Digital Library
General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes (open access)

General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes

Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and thick (height H to cylindrical radius R ratio of |H/R| {approx} 0.2-1) accretion flows around BHs with various dimensionless spins (a/M, with BH mass M) and with initially toroidally-dominated ({phi}-directed) and poloidally-dominated (R-z directed) magnetic fields. Firstly, for toroidal field models and BHs with high enough |a/M|, coherent large-scale (i.e. >> H) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate transient relativistic jets. Secondly, for poloidal field models, poloidal magnetic flux readily accretes through the disk from large radii and builds-up to a natural saturation point near the BH. While models with |H/R| {approx} 1 and |a/M| {le} 0.5 do not launch jets due to quenching by mass infall, for sufficiently high |a/M| or low |H/R| the polar magnetic field compresses the inflow into a geometrically thin highly non-axisymmetric 'magnetically choked accretion flow' (MCAF) within which the standard linear magneto-rotational instability is suppressed. The condition of a highly-magnetized state over most of the horizon is optimal for the Blandford-Znajek mechanism that generates persistent relativistic jets with …
Date: April 26, 2012
Creator: McKinney, Jonathan C.; Tchekhovskoy, Alexander & Blandford, Roger D.
Object Type: Article
System: The UNT Digital Library
GMTSAR: An InSAR Processing System Based on Generic Mapping Tools (open access)

GMTSAR: An InSAR Processing System Based on Generic Mapping Tools

None
Date: April 26, 2011
Creator: Sandwell, D.; Mellors, R.; Tong, X.; Wei, M. & Wessel, P.
Object Type: Report
System: The UNT Digital Library
High Statistics Analysis using Anisotropic Clover Lattices: (IV) Volume Dependence of Light Hadron Masses (open access)

High Statistics Analysis using Anisotropic Clover Lattices: (IV) Volume Dependence of Light Hadron Masses

None
Date: April 26, 2011
Creator: Beane, S.; Chang, E.; Detmold, W.; Lin, H. W.; Luu, T.; Orginos, K. et al.
Object Type: Article
System: The UNT Digital Library
Hydrogen Storage in Metal-Organic Frameworks (open access)

Hydrogen Storage in Metal-Organic Frameworks

Conventional storage of large amounts of hydrogen in its molecular form is difficult and expensive because it requires employing either extremely high pressure gas or very low temperature liquid. Because of the importance of hydrogen as a fuel, the DOE has set system targets for hydrogen storage of gravimetric (5.5 wt%) and volumetric (40 g L-1) densities to be achieved by 2015. Given that these are system goals, a practical material will need to have higher capacity when the weight of the tank and associated cooling or regeneration system is considered. The size and weight of these components will vary substantially depending on whether the material operates by a chemisorption or physisorption mechanism. In the latter case, metal-organic frameworks (MOFs) have recently been identified as promising adsorbents for hydrogen storage, although little data is available for their sorption behavior. This grant was focused on the study of MOFs with these specific objectives. (1) To examine the effects of functionalization, catenation, and variation of the metal oxide and organic linkers on the low-pressure hydrogen adsorption properties of MOFs. (2) To develop a strategy for producing MOFs with high surface area and porosity to reduce the dead space and increase the hydrogen …
Date: April 26, 2012
Creator: Yaghi, Omar M.
Object Type: Report
System: The UNT Digital Library
IMPACT OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION MELT RATE STUDIES (open access)

IMPACT OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION MELT RATE STUDIES

This study was undertaken to evaluate the potential impacts of the Small Column Ion Exchange (SCIX) streams - particularly the addition of Monosodium Titanate (MST) and Crystalline Silicotitanate (CST) - on the melt rate of simulated feed for the Defense Waste Processing Facility (DWPF). Additional MST was added to account for contributions from the Salt Waste Processing Facility (SWPF). The Savannah River National Laboratory (SRNL) Melt Rate Furnace (MRF) was used to evaluate four melter feed compositions: two with simulated SCIX and SWPF material and two without. The Slurry-fed Melt Rate Furnace (SMRF) was then used to compare two different feeds: one with and one without bounding concentrations of simulated SCIX and SWPF material. Analyses of the melter feed materials confirmed that they met their targeted compositions. Four feeds were tested in triplicate in the MRF. The linear melt rates were determined by using X-ray computed tomography to measure the height of the glass formed along the bottom of the beakers. The addition of the SCIX and SWPF material reduced the average measured melt rate by about 10% in MRF testing, although there was significant scatter in the data. Two feeds were tested in the SMRF. It was noted that …
Date: April 26, 2011
Creator: Fox, K.; Miller, D. & Koopman, D.
Object Type: Report
System: The UNT Digital Library
IMPACTS OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION: KT08, KT09, AND KT10-SERIES GLASS COMPOSITIONS (open access)

IMPACTS OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION: KT08, KT09, AND KT10-SERIES GLASS COMPOSITIONS

This report is the fourth in a series of studies of the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility (SWPF) is also considered in the study. The KT08-series of glasses was designed to evaluate any impacts of the inclusion of uranium and thorium in glasses containing the SCIX components. The KT09-series of glasses was designed to study the effect of increasing Al{sub 2}O{sub 3} and K{sub 2}O concentrations on the propensity for crystallization of titanium containing phases in high TiO{sub 2} concentration glasses. Earlier work on the KT05-series glasses recommended that the impact of these two components be studied further. Increased Al{sub 2}O{sub 3} concentrations have been shown to improve the properties and performance of high waste loading glasses, and K{sub 2}O has been reported to improve the retention of TiO{sub 2} in silicate glasses. The KT10-series of compositions was designed to evaluate any impacts of the SCIX components at concentrations 50% higher than currently projected.a The glasses were fabricated in …
Date: April 26, 2011
Creator: Fox, K. & Edwards, T.
Object Type: Report
System: The UNT Digital Library
Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications (open access)

Improved Meteorological Input for Atmospheric Release Decision support Systems and an Integrated LES Modeling System for Atmospheric Dispersion of Toxic Agents: Homeland Security Applications

When hazardous material is accidently or intentionally released into the atmosphere, emergency response organizations look to decision support systems (DSSs) to translate contaminant information provided by atmospheric models into effective decisions to protect the public and emergency responders and to mitigate subsequent consequences. The Department of Homeland Security (DHS)-led Interagency Modeling and Atmospheric Assessment Center (IMAAC) is one of the primary DSSs utilized by emergency management organizations. IMAAC is responsible for providing 'a single piont for the coordination and dissemination of Federal dispersion modeling and hazard prediction products that represent the Federal position' during actual or potential incidents under the National Response Plan. The Department of Energy's (DOE) National Atmospheric Release Advisory Center (NARAC), locatec at the Lawrence Livermore National Laboratory (LLNL), serves as the primary operations center of the IMAAC. A key component of atmospheric release decision support systems is meteorological information - models and data of winds, turbulence, and other atmospheric boundary-layer parameters. The accuracy of contaminant predictions is strongly dependent on the quality of this information. Therefore, the effectiveness of DSSs can be enhanced by improving the meteorological options available to drive atmospheric transport and fate models. The overall goal of this project was to develop and …
Date: April 26, 2010
Creator: Arnold, E; Simpson, M; Larsen, S; Gash, J; Aluzzi, F; Lundquist, J et al.
Object Type: Report
System: The UNT Digital Library
Integrated X-Ray Reflectivity Measurements for Elliptically Curved PET Crystals (open access)

Integrated X-Ray Reflectivity Measurements for Elliptically Curved PET Crystals

Spectroscopy provides valuable information about the temperature and density of a compressed pellet in a plasma. Elliptically curved pentaerythritol (PET) crystals are used as components for spectrometers. Their elliptical geometry gives several advantages related to spectral energy range, source focus, and spectral image compression.[1] The crystal curvature increases the spectrometer throughput but at the cost of a loss in resolution. Four different crystals are used in a spectrometer at the National Ignition Facility (NIF) target chamber at Lawrence Livermore National Laboratory (LLNL). Figure 1 shows the arrangement of the elliptical PET crystals in the snout of a NIF target diagnostic shown in Figure 2. The spectrum from the crystals is captured by four image plates located behind the crystals. A typical mandrel, the darkened section, upon which the PET crystal is glued, is shown in Figure 3, which also shows the complete ellipse. There are four elliptical segment types, each having the same major axis but a different minor axis. The crystals are 150 mm long in the diffraction direction and 25.4 mm high. Two crystals of each type were calibrated. The throughput for each spectrometer is determined by the integrated reflectivity of the PET crystal.[1] The goal of this …
Date: April 26, 2012
Creator: Haugh, M. J.; Ross, P. W.; Regan, P. W.; Magoon, J.; Shoup, M. J.; Barrios, M. A. et al.
Object Type: Article
System: The UNT Digital Library
Key results from SB8 simulant flowsheet studies (open access)

Key results from SB8 simulant flowsheet studies

Key technically reviewed results are presented here in support of the Defense Waste Processing Facility (DWPF) acceptance of Sludge Batch 8 (SB8). This report summarizes results from simulant flowsheet studies of the DWPF Chemical Process Cell (CPC). Results include: Hydrogen generation rate for the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles of the CPC on a 6,000 gallon basis; Volume percent of nitrous oxide, N2O, produced during the SRAT cycle; Ammonium ion concentrations recovered from the SRAT and SME off-gas; and, Dried weight percent solids (insoluble, soluble, and total) measurements and density.
Date: April 26, 2013
Creator: Koopman, D. C.
Object Type: Report
System: The UNT Digital Library
Materials Performance in USC Steam Portland (open access)

Materials Performance in USC Steam Portland

Goals of the U.S. Department of Energy's Advanced Power Systems Initiatives include power generation from coal at 60% efficiency, which requires steam conditions of up to 760 C and 340 atm, co-called advanced ultrasupercritical (A-USC) steam conditions. A limitation to achieving the goal is a lack of cost-effective metallic materials that can perform at these temperatures and pressures. Some of the more important performance limitations are high-temperature creep strength, fire-side corrosion resistance, and steam-side oxidation resistance. Nickel-base superalloys are expected to be the materials best suited for steam boiler and turbine applications above about 675 C. Specific alloys of interest include Haynes 230 and 282, Inconel 617, 625 and 740, and Nimonic 263. Further validation of a previously developed chromia evaporation model is shown by examining the reactive evaporation effects resulting from exposure of Haynes 230 and Haynes 282 to moist air environments as a function of flow rate and water content. These two alloys differ in Ti and Mn contents, which may form outer layers of TiO{sub 2} or Cr-Mn spinels. This would in theory decrease the evaporation of Cr{sub 2}O{sub 3} from the scale by decreasing the activity of chromia at the scale surface, and be somewhat self-correcting …
Date: April 26, 2011
Creator: Holcomb, G.R.; Tylczak, J. & Hu, R.
Object Type: Article
System: The UNT Digital Library
Measurement of electron-hole friction in an n-doped GaAs/AlGaAs quantum well using optical transient-grating spectroscopy (open access)

Measurement of electron-hole friction in an n-doped GaAs/AlGaAs quantum well using optical transient-grating spectroscopy

We use phase-resolved transient grating spectroscopy to measure the drift and diffusion of electron-hole density waves in a semiconductor quantum well. The unique aspects of this optical probe allow us to determine the frictional force between a two-dimensional Fermi liquid of electrons and a dilute gas of holes. Knowledge of electron-hole friction enables prediction of ambipolar dynamics in high-mobility electron systems.
Date: April 26, 2011
Creator: Yang, Luyi; Koralek, J. D.; Orenstein, J.; Tibbetts, D. R.; Reno, J. L. & Lilly, M. P.
Object Type: Article
System: The UNT Digital Library
Molecular Characterization of Bacterial Respiration on Minerals (open access)

Molecular Characterization of Bacterial Respiration on Minerals

The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully …
Date: April 26, 2013
Creator: Blake, Robert C.
Object Type: Report
System: The UNT Digital Library
A New Limit on Time-Reversal Violation in Beta Decay (open access)

A New Limit on Time-Reversal Violation in Beta Decay

We report the results of an improved determination of the triple correlation DP {center_dot} (p{sub e} x p{sub v}) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is D = (-0.96 {+-} 1.89(stat) {+-} 1.01(sys)) x 10{sup -4}. The corresponding phase between g{sub A} and g{sub V} is {phi}{sub AV} = 180.013{sup o} {+-} 0.028{sup o} (68% confidence level). This result represents the most sensitive measurement of D in nuclear beta decay.
Date: April 26, 2011
Creator: Mumm, H P; Chupp, T E; Cooper, R L; Coulter, K P; Freedman, S J; Fujikawa, B K et al.
Object Type: Article
System: The UNT Digital Library
Non-linear Dynamics Of Toroidicity-induced Alfven Eigenmodes On The National Spherical Torus Experiment (open access)

Non-linear Dynamics Of Toroidicity-induced Alfven Eigenmodes On The National Spherical Torus Experiment

The National Spherical Torus Experiment (NSTX, [M. Ono et al., Nucl. Fusion 40, 557 (2000)]) routinely operates with neutral beam injection as the primary system for heating and current drive. The resulting fast ion population is super-Alfv#19;enic, with velocities 1 < vfast=vAlfven < 5. This provides a strong drive for toroidicity-induced Alfv#19;en eigenmodes (TAEs). As the discharge evolves, the fast ion population builds up and TAEs exhibit increasing bursts in amplitude and down-chirps in frequency, which eventually lead to a so-called TAE avalanche. Avalanches cause large (≤ 30%) fast ion losses over ~ 1 ms, as inferred from the neutron rate. The increased fast ion losses correlate with a stronger activity in the TAE band. In addition, it is shown that a n = 1 mode with frequency well below the TAE gap appears in the Fourier spectrum of magnetic fluctuations as a result of non-linear mode coupling between TAEs during avalanche events. The non-linear coupling between modes, which leads to enhanced fast ion transport during avalanches, is investigated.
Date: April 26, 2011
Creator: Podesta, M.; Crocker, N. A.; Fredrickson, E. D.; Gorelenkov, N. N.; Heidbrink, W. W.; Kubota, S. et al.
Object Type: Report
System: The UNT Digital Library
Nuclear Material Attractiveness: An Assessment of Material From Phwr's in a Closed Thorium Fuel Cycle (open access)

Nuclear Material Attractiveness: An Assessment of Material From Phwr's in a Closed Thorium Fuel Cycle

This paper examines the attractiveness of material mixtures containing special nuclear materials (SNM) associated with reprocessing and the thorium-based LWR fuel cycle. This paper expands upon the results from earlier studies that examined the attractiveness of SNM associated with the reprocessing of spent light water reactor (LWR) fuel by various reprocessing schemes and the recycle of plutonium as a mixed oxide (MOX) fuel in LWR. This study shows that {sup 233}U that is produced in thorium-based fuel cycles is very attractive for weapons use. Consistent with other studies, these results also show that all fuel cycles examined to date need to be rigorously safeguarded and provided moderate to high levels of physical protection. These studies were performed at the request of the United States Department of Energy (DOE), and are based on the calculation of 'attractiveness levels' that has been couched in terms chosen for consistency with those normally used for nuclear materials in DOE nuclear facilities. The methodology and key findings will be presented.
Date: April 26, 2010
Creator: Sleaford, B. W.; Collins, B. A.; Ebbinghaus, B. B.; Bathke, C. G.; Prichard, A. W.; Wallace, R. K. et al.
Object Type: Article
System: The UNT Digital Library
On the Singularity of the Vlasov-Poisson System (open access)

On the Singularity of the Vlasov-Poisson System

The Vlasov-Poisson system can be viewed as the collisionless limit of the corresponding Fokker- Planck-Poisson system. It is reasonable to expect that the result of Landau damping can also be obtained from the Fokker-Planck-Poisson system when the collision frequency v#23; approaches zero. However, we show that the colllisionless Vlasov-Poisson system is a singular limit of the collisional Fokker-Planck-Poisson system, and Landau's result can be recovered only as the #23; approaching zero from the positive side.
Date: April 26, 2013
Creator: and Hong Qin, Jian Zheng
Object Type: Report
System: The UNT Digital Library