Resource Type

The AIG Rescue, Its Impact on Markets, and the Government's Exit Strategy (open access)

The AIG Rescue, Its Impact on Markets, and the Government's Exit Strategy

June report of the U.S. Congressional Oversight Panel describing their activities and findings regarding the impact of the 2007-2008 financial crisis on American International Group (AIG) and the subsequent rescue of the firm by the financial assistance received from the federal government.
Date: June 10, 2010
Creator: United States. Congressional Oversight Panel.
System: The UNT Digital Library
The Unique Treatment of GMAC Under the TARP (open access)

The Unique Treatment of GMAC Under the TARP

March report of the U.S. Congressional Oversight Panel describing their activities and findings regarding the state of the General Motors Acceptance Corporation during the 2007-2008 financial crisis and the financial assistance received by the firm by the federal government.
Date: March 10, 2010
Creator: United States. Congressional Oversight Panel.
System: The UNT Digital Library
Modular Coils and Plasma Configurations for Quasi-axisymmetric Stellarators (open access)

Modular Coils and Plasma Configurations for Quasi-axisymmetric Stellarators

Characteristics of modular coils for quasi-axisymmetric stellarators that are related to the plasma aspect ratio, number of field periods and rotational transform have been examined systematically. It is observed that, for a given plasma aspect ratio, the coil complexity tends to increase with the increased number of field periods. For a given number of field periods, the toroidal excursion of coil winding is reduced as the plasma aspect ratio is increased. It is also clear that the larger the coil-plasma separation is, the more complex the coils become. It is further demonstrated that it is possible to use other types of coils to complement modular coils to improve both the physics and the modular coil characteristics.
Date: September 10, 2010
Creator: Ku, L. P. & Boozer, A. H.
System: The UNT Digital Library
Some Considerations and Techniques for the Predictive Simulation of Global Instabilities in Tokamaks (open access)

Some Considerations and Techniques for the Predictive Simulation of Global Instabilities in Tokamaks

This is a write-up of a lecture given at the Fourth ITER International Summer School held at the IFS, U. Texas in June 2010. A simple rigid plasma model is used to show that axisymmetric plasma instabilities (in two-dimensions) will occur on a resistive timescale and do not depend on the plasma mass. This is the justification for ignoring the inertial term in two-dimensional studies of plasma shape control and vertical stability. In three dimensions, it is not normally possible to ignore the inertial terms when computing plasma instabilities. This results in a stiff system of equations (with multiple timescales) in which the driving terms causing plasma instabilities are small compared with the stable compressive terms. Techniques are described for implicit time integration and for representing the vector fields in a way to facilitate obtaining accurate solutions for plasma instabilities when a strong background magnetic field is present.
Date: September 10, 2010
Creator: Jardin, S. C.
System: The UNT Digital Library
Current Density and Plasma Displacement Near Perturbed Rational Surface (open access)

Current Density and Plasma Displacement Near Perturbed Rational Surface

The current density in the vicinity of a rational surface of a force-free magnetic field subjected to an ideal perturbation is shown to be the sum of both a smooth and a delta-function distribution, which give comparable currents. The maximum perturbation to the smooth current density is comparable to a typical equilibrium current density and the width of the layer in which the current flows is shown to be proportional to the perturbation amplitude. In the standard linearized theory, the plasma displacement has an unphysical jump across the rational surface, but the full theory gives a continuous displacement.
Date: October 10, 2010
Creator: Boozer, A. H. & Pomphrey, N.
System: The UNT Digital Library
Thermal Cooling Limits of Sbotaged Spent Fuel Pools (open access)

Thermal Cooling Limits of Sbotaged Spent Fuel Pools

To develop the understanding and predictive measures of the post “loss of water inventory” hazardous conditions as a result of the natural and/or terrorist acts to the spent fuel pool of a nuclear plant. This includes the thermal cooling limits to the spent fuel assembly (before the onset of the zircaloy ignition and combustion), and the ignition, combustion, and the subsequent propagation of zircaloy fire from one fuel assembly to others
Date: September 10, 2010
Creator: Hughes, Dr. Thomas G. & Lin, Dr. Thomas F.
System: The UNT Digital Library
Sludge Batch Supplemental Srat Runs Effects of Yield Stress and Cycle Time Increase (open access)

Sludge Batch Supplemental Srat Runs Effects of Yield Stress and Cycle Time Increase

The Defense Waste Processing Facility (DWPF) has transitioned from Sludge Batch 5 (SB5) processing to Sludge Batch 6 (SB6) processing. Phase III-Tank 40 Chemical Process Cell (CPC) flowsheet simulations have been completed to determine the initial processing conditions for the DWPF transition. The impact of higher yield stress (SB-25) and cycle time extension (SB6-26) on the physical and chemical effects of SB6 processing during the SRAT (Sludge Receipt and Adjustment Tank) cycle were evaluated. No significant impacts on the SRAT chemistry were noted during the higher yield stress run. In particular, no impact on mercury stripping was noted, indicating that settling of elemental mercury was not the primary factor in the low mercury recovery noted in the flowsheet testing. The SRAT product from this run retained the higher yield stress of the starting sludge. The run indicated that ultrasonication is an effective tool to increase the yield stress of simulants to targeted values and the chemistry of downstream processing is not impacted. Significant differences were noted in the cycle time extension test compared to the Phase III flowsheet baseline runs. Large decreases in the ammonia and hydrogen generation rates were noted along with reduced mercury stripping efficiency. The latter effect …
Date: August 10, 2010
Creator: Fernandez, A.
System: The UNT Digital Library
FABSOAR--A Fabry-Perot Spectrometer for Oxygen A-band Research Final Technical Report (open access)

FABSOAR--A Fabry-Perot Spectrometer for Oxygen A-band Research Final Technical Report

Because this was a Phase I project, it did not add extensively to the body of A-band knowledge. There was no basic research performed on that subject. The principal addition was that a mechanical and optical design for a triple-etalon Fabry-Perot interferometer (FABSOAR) capable of A-band sensing was sketched out and shown to be within readily feasible instrument fabrication parameters. The parameters for the proposed triple-etalon Fabry-Perot were shown to be very similar to existing Fabry-Perots built by Scientific Solutions. The mechanical design for the FABSOAR instrument incorporated the design of previous Scientific Solutions imagers, condensing the three three-inch-diameter etalons into a single, sturdy tube. The design allowed for the inclusion of a commercial off-the-shelf (COTS) filter wheel and a thermocooled CCD detector from Andor. The tube has supports to mount to a horizontal or vertical opticaltable surface, and was to be coupled to a Scientific Solutions pointing head at the Millstone Hill Observatory in Massachusetts for Phase II calibration and testing.
Date: September 10, 2010
Creator: Watchorn, Steven
System: The UNT Digital Library
Magnetic Processing – A Pervasive Energy Efficient Technology for Next Generation Materials for Aerospace and Specialty Steel Markets (open access)

Magnetic Processing – A Pervasive Energy Efficient Technology for Next Generation Materials for Aerospace and Specialty Steel Markets

Thermomagnetic Magnetic Processing is an exceptionally fertile, pervasive and cross-cutting technology that is just now being recognized by several major industry leaders for its significant potential to increase energy efficiency and materials performance for a myriad of energy intensive industries in a variety of areas and applications. ORNL has pioneered the use and development of large magnetic fields in thermomagnetically processing (T-MP) materials for altering materials phase equilibria and transformation kinetics. ORNL has discovered that using magnetic fields, we can produce unique materials responses. T-MP can produce unique phase stabilities & microstructures with improved materials performance for structural and functional applications not achieved with traditional processing techniques. These results suggest that there are unprecedented opportunities to produce significantly enhanced materials properties via atomistic level (nano-) microstructural control and manipulation. ORNL (in addition to others) have shown that grain boundary chemistry and precipitation kinetics are also affected by large magnetic fields. This CRADA has taken advantage of ORNL’s unique, custom-designed thermo-magnetic, 9 Tesla superconducting magnet facility that enables rapid heating and cooling of metallic components within the magnet bore; as well as ORNL’s expertise in high magnetic field (HMF) research. Carpenter Technologies, Corp., is a a US-based industrial company, that provides …
Date: September 10, 2010
Creator: Mackiewicz-Ludtka, G.; Ludtka, G. M.; Ray, P. & Magee, J.
System: The UNT Digital Library
Ab initio Based Modeling of Radiation Effects in Multi-Component Alloys:  Final Scientific/Technical Report (open access)

Ab initio Based Modeling of Radiation Effects in Multi-Component Alloys: Final Scientific/Technical Report

The project began March 13, 2006, allocated for three years, and received a one year extension from March 13, 2009 to March 12, 2010. It has now completed 48 of 48 total months. The project was focused on using ab initio methods to gain insights into radiation induced segregation (RIS) in Ni-Fe-Cr alloys. The project had the following key accomplishments • Development of a large database of ab initio energetics that can be used by many researchers in the future for increased understanding of this system. For example, we have the first calculations showing a dramatic stabilization effect of Cr-Cr interstitial dumbbells in Ni. • Prediction of both vacancy and interstitial diffusion constants for Ni-Cr and Ni-Fe for dilute Cr and Fe. This work included generalization of widely used multifrequency models to make use of ab initio derived energetics and thermodynamics. • Prediction of qualitative trends of RIS from vacancy and interstitial mechanisms, suggesting the two types of defect fluxes drive Cr RIS in opposite directions. • Detailed kinetic Monte Carlo modeling of diffusion by vacancy mechanism in Ni-Cr as a function of Cr concentration. The results demonstrate that Cr content can have a significant effect on RIS. • Development …
Date: June 10, 2010
Creator: Morgan, Dane
System: The UNT Digital Library
Heterotrophic Soil Respiration in Warming Experiments: Using Microbial Indicators to Partition Contributions from Labile and Recalcitrant Soil Organic Carbon. Final Report (open access)

Heterotrophic Soil Respiration in Warming Experiments: Using Microbial Indicators to Partition Contributions from Labile and Recalcitrant Soil Organic Carbon. Final Report

The central objective of the proposed work was to develop a genomic approach (nucleic acid-based) that elucidates the mechanistic basis for the observed impacts of experimental soil warming on forest soil respiration. The need to understand the mechanistic basis arises from the importance of such information for developing effective adaptation strategies for dealing with projected climate change. Specifically, robust predictions of future climate will permit the tailoring of the most effective adaptation efforts. And one of the greatest uncertainties in current global climate models is whether there will be a net loss of carbon from soils to the atmosphere as climate warms. Given that soils contain approximately 2.5 times as much carbon as the atmosphere, a net loss could lead to runaway climate warming. Indeed, most ecosystem models predict that climate warming will stimulate microbial decomposition of soil carbon, producing such a positive feedback to rising global temperatures. Yet the IPCC highlights the uncertainty regarding this projected feedback. The uncertainty arises because although warming-experiments document an initial increase in the loss of carbon from soils, the increase in respiration is short-lived, declining to control levels in a few years. This attenuation could result from changes in microbial physiology with temperature. …
Date: June 10, 2010
Creator: Bradford, M. A.; Melillo, J. M.; Reynolds, J. F.; Treseder, K. K. & Wallenstein, M. D.
System: The UNT Digital Library
Fuel cycle analysis of once-through nuclear systems. (open access)

Fuel cycle analysis of once-through nuclear systems.

Once-through fuel cycle systems are commercially used for the generation of nuclear power, with little exception. The bulk of these once-through systems have been water-cooled reactors (light-water and heavy water reactors, LWRs and HWRs). Some gas-cooled reactors are used in the United Kingdom. The commercial power systems that are exceptions use limited recycle (currently one recycle) of transuranic elements, primarily plutonium, as done in Europe and nearing deployment in Japan. For most of these once-through fuel cycles, the ultimate storage of the used (spent) nuclear fuel (UNF, SNF) will be in a geologic repository. Besides the commercial nuclear plants, new once-through concepts are being proposed for various objectives under international advanced nuclear fuel cycle studies and by industrial and venture capital groups. Some of the objectives for these systems include: (1) Long life core for remote use or foreign export and to support proliferation risk reduction goals - In these systems the intent is to achieve very long core-life with no refueling and limited or no access to the fuel. Most of these systems are fast spectrum systems and have been designed with the intent to improve plant economics, minimize nuclear waste, enhance system safety, and reduce proliferation risk. Some …
Date: August 10, 2010
Creator: Kim, T. K.; Taiwo, T. A. & Division, Nuclear Engineering
System: The UNT Digital Library
Results from the Cooler and Lead Tests (open access)

Results from the Cooler and Lead Tests

The report presents the results of testing MICE spectrometer magnet current leads on a test apparatus that combines both the copper leads and the high temperature superconducting (HTS) leads with a single Cryomech PT415 cooler and liquid helium tank. The current is carried through the copper leads from 300 K to the top of the HTS leads. The current is then carried through the HTS leads to a feed-through from the vacuum space to the inside of a liquid helium tank. The experiment allows one to measure the performance of both cooler stages along with the performance of the leads. While the leads were powered we measured the voltage drops through the copper leads, through the HTS leads, through spliced to the feed-through, through the feed-through and through the low-temperature superconducting loop that connects one lead to the other. Measurements were made using the leads that were used in spectrometer magnet 1A and spectrometer magnet 2A. These are the same leads that were used for Superbend and Venus magnets at LBNL. The IL/A for these leads was 5.2 x 10{sup 6} m{sup -1}. The leads turned out to be too long. The same measurements were made using the leads that …
Date: June 10, 2010
Creator: Green, Michael A.
System: The UNT Digital Library
Consolidation of K Basin Sludge Data and Experiences on Agglomerate Formation (open access)

Consolidation of K Basin Sludge Data and Experiences on Agglomerate Formation

The formation of high sludge strength agglomerates is a key concern to the Sludge Treatment Project (STP) to ensure the sludge can be retrieved after planned storage for up to 10 years in Sludge Transport and Storage Containers (STSC) at T Plant. This report addresses observations of agglomerate formation, conditions that the data shows lead to agglomeration, the frequency of agglomerate formation and postulated physiochemical mechanisms that may lead to agglomeration. Although the exact underlying chemistry of K Basin sludge agglomerate formation is not known, the factors that lead to agglomeration formation, based on observations, are as follows: (1) High Total Uranium Content (i.e., sample homogeneity and influence from other constituents); (2) Distribution of Uranium Phases (i.e., extent of conversion from uraninite to uranium oxide hydroxide compounds); (3) Sample Dry-out (loss of cover water); (4) Elevated temperature; (5) Solubility ofU(IV) phases vs. U(VI) phases; and (6) Long storage times. Agglomerated sludge has occurred infrequently and has only been observed in four laboratory samples, five samples subjected to hydrothermal testing (performed for 7 to 10 hours at {approx}185 C and 225 psig), and indirectly during six sampling events in the KE Basin. In the four laboratory samples where agglomerates were observed, …
Date: June 10, 2010
Creator: Hill, S.R.
System: The UNT Digital Library
25 Year Lifetime for Flexible Buildings Integrated Photovoltaics (open access)

25 Year Lifetime for Flexible Buildings Integrated Photovoltaics

Although preliminary proof-of-principle of the efficacy of barrier materials and processes, first developed by Battelle at PNNL and commercialized by Vitex, has been demonstrated at the laboratory scale, there are several challenges to the practical commercial implementation of these developments in the Buildings Integrated Photovoltaics (BIPV) market. Two important issues that are addressed in this project are identifying a low cost substrate material that can survive in the outside environment (rain, heat, dust, hail, etc.) for 25 years and developing an encapsulation method for the photovoltaic (PV) cells that can meet the required barrier performance without driving the cost of the total barrier package out of range (remaining below $3.00/Wp). Without these solutions, current encapsulation technologies will limit the use of PV for BIPV applications. Flexible, light-weight packaging that can withstand 25 years in the field is required for a totally flexible integrated PV package. The benefit of this research is to make substantial progress in the development of a cost-effective, viable thin film barrier package which will be a critical enabling technology to meet the Solar America Initiative cost and device reliability goals, and to make photovoltaics (PV) more cost-competitive with electricity generated using fossil fuels. Increased PV installations …
Date: July 10, 2010
Creator: Gross, Mark E.
System: The UNT Digital Library
317/319 Phytoremediation site monitoring report - 2009 growing season : final report. (open access)

317/319 Phytoremediation site monitoring report - 2009 growing season : final report.

In 1999, Argonne National Laboratory (Argonne) designed and installed a series of engineered plantings consisting of a vegetative cover system and approximately 800 hybrid poplars and willows rooting at various predetermined depths. The plants were installed using various methods including Applied Natural Science's TreeWell{reg_sign} system. The goal of the installation was to protect downgradient surface and groundwater by intercepting the contaminated groundwater with the tree roots, removing moisture from the upgradient soil area, reducing water infiltration, preventing soil erosion, degrading and/or transpiring the residual volatile organic compounds (VOCs), and removing tritium from the subsoil and groundwater. This report presents the results of the monitoring activities conducted by Argonne's Energy Systems (ES) Division in the growing season of 2009. Monitoring of the planted trees began soon after the trees were installed in 1999 and has been conducted every summer since then. As the trees grew and consolidated their growth into the contaminated soil and groundwater, their exposure to the contaminants was progressively shown through tissue sampling. During the 2009 sampling campaign, VOC concentrations found in the French Drain area were in general consistent with or slightly lower than the 2008 results. Additionally, closely repeated, stand wide analyses showed contaminant fluctuations that …
Date: February 10, 2010
Creator: Negri, C .N.; Benda, P. L.; Gopalakrishnan, G. & Systems, Energy
System: The UNT Digital Library
STRUCTURAL INTERACTIONS OF HYDROGEN WITH BULK AMORPHOUS MICROSTRUCTURES IN METALLIC SYSTEMS UNDERSTANDING THE ROLE OF PARTIAL CRYSTALLINITY ON PERMEATION AND EMBRITTLEMENT (open access)

STRUCTURAL INTERACTIONS OF HYDROGEN WITH BULK AMORPHOUS MICROSTRUCTURES IN METALLIC SYSTEMS UNDERSTANDING THE ROLE OF PARTIAL CRYSTALLINITY ON PERMEATION AND EMBRITTLEMENT

The development of metallic glasses in bulk form has led to a resurgence of interest into the utilization of these materials for a variety of applications. A potentially exciting application for these bulk metallic glass (BMG) materials is their use as composite membranes to replace high cost Pd/Pd-alloy membranes for enhanced gas separation processes. One of the major drawbacks to the industrial use of Pd/Pd-alloy membranes is that during cycling above and below a critical temperature an irreversible change takes place in the palladium lattice structure which can result in significant damage to the membrane. Furthermore, the cost associated with Pd-based membranes is a potential detractor for their continued use and BMG alloys offer a potentially attractive alternative. Several BMG alloys have been shown to possess high permeation rates, comparable to those measured for pure Pd metal. In addition, high strength and toughness when either in-situ or ex-situ second phase dispersoids are present. Both of these properties, high permeation and high strength/toughness, potentially make these materials attractive for gas separation membranes that could resist hydrogen 'embrittlement'. However, a fundamental understanding of the relationship between partially crystalline 'structure'/devitrification and permeation/embrittlement in these BMG materials is required in order to determine the …
Date: May 10, 2010
Creator: Brinkman, Kyle; Fox, Elise; Korinko, Paul & Adams, Thad
System: The UNT Digital Library
The Sulfur-Iodine Cycle: Process Analysis and Design Using Comprehensive Phase Equilibrium Measurements and Modeling (open access)

The Sulfur-Iodine Cycle: Process Analysis and Design Using Comprehensive Phase Equilibrium Measurements and Modeling

Of the 100+ thermochemical hydrogen cycles that have been proposed, the Sulfur-Iodine (S-I) Cycle is a primary target of international interest for the centralized production of hydrogen from nuclear power. However, the cycle involves complex and highly nonideal phase behavior at extreme conditions that is only beginning to be understood and modeled for process simulation. The consequence is that current designs and efficiency projections have large uncertainties, as they are based on incomplete data that must be extrapolated from property models. This situation prevents reliable assessment of the potential viability of the system and, even more, a basis for efficient process design. The goal of this NERI award (05-006) was to generate phase-equilibrium data, property models, and comprehensive process simulations so that an accurate evaluation of the S-I Cycle could be made. Our focus was on Section III of the Cycle, where the hydrogen is produced by decomposition of hydroiodic acid (HI) in the presence of water and iodine (I2) in a reactive distillation (RD) column. The results of this project were to be transferred to the nuclear hydrogen community in the form of reliable flowsheet models for the S-I process. Many of the project objectives were achieved. At Clemson …
Date: January 10, 2010
Creator: Thies, Mark C.; O'Connell, J. P. & Gorensek, Maximilian B.
System: The UNT Digital Library
Liquid X-ray diffraction on the NIF: Phase transitions into and within the liquid phase (open access)

Liquid X-ray diffraction on the NIF: Phase transitions into and within the liquid phase

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Date: June 10, 2010
Creator: Eggert, J
System: The UNT Digital Library
Materials at Atomic Pressure (open access)

Materials at Atomic Pressure

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Date: June 10, 2010
Creator: Hicks, D
System: The UNT Digital Library
CHASM Challenge Problem: Lagrangian Hydrodynamics (open access)

CHASM Challenge Problem: Lagrangian Hydrodynamics

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Date: September 10, 2010
Creator: Hornung, R.; Keasler, J. & Gokhale, M.
System: The UNT Digital Library
Eagle Nebula Experiments on NIF: NIF Facility Time Proposal (open access)

Eagle Nebula Experiments on NIF: NIF Facility Time Proposal

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Date: June 10, 2010
Creator: Cooper, A. B.; Remington, B. A.; Pound, M. W.; Moore, A. S.; MacLaren, S. A.; Williams, R. J. et al.
System: The UNT Digital Library
Right Size Determining the Staff Necessary to Sustain Simulation and Computing Capabilities for Nuclear Security (open access)

Right Size Determining the Staff Necessary to Sustain Simulation and Computing Capabilities for Nuclear Security

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Date: September 10, 2010
Creator: Nikkel, D J
System: The UNT Digital Library
X-ray diffraction studies of dynamically compressed diamond (open access)

X-ray diffraction studies of dynamically compressed diamond

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Date: June 10, 2010
Creator: Eggert, J
System: The UNT Digital Library