Resource Type

Assessing the TARP on the Eve of Its Expiration (open access)

Assessing the TARP on the Eve of Its Expiration

September report of the U.S. Congressional Oversight Panel describing their activities and findings regarding the results of the Treasury's Troubled Asset Relief Program(TARP) in mitigating the effects of the 2007 financial crisis.
Date: September 16, 2010
Creator: United States. Congressional Oversight Panel.
System: The UNT Digital Library
Examining the Consequences of Mortgage Irregularities for the Financial Stability and Foreclosure Mitigation (open access)

Examining the Consequences of Mortgage Irregularities for the Financial Stability and Foreclosure Mitigation

November report of the U.S. Congressional Oversight Panel describing their activities and findings regarding mortgage document irregularities, including sections on background information, legal consequences, litigation, and the impact on banks and the housing market.
Date: November 16, 2010
Creator: United States. Congressional Oversight Panel.
System: The UNT Digital Library
Final Work Plan : Phase II Investigation of Potential Contamination at the Former CCC/USDA Grain Storage Facility in Savannah, Missouri. (open access)

Final Work Plan : Phase II Investigation of Potential Contamination at the Former CCC/USDA Grain Storage Facility in Savannah, Missouri.

From approximately 1949 until 1970, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility on federally owned property approximately 0.25 mi northwest of Savannah, Missouri (Figure 1.1). During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In November 1998, carbon tetrachloride was detected in a private well (Morgan) roughly 50 ft south of the former CCC/USDA facility, as a result of statewide screening of private wells near former CCC/USDA facilities, conducted in Missouri by the U.S. Environmental Protection Agency (EPA 1999). The 1998 and subsequent investigations by the EPA and the Missouri Department of Natural Resources (MoDNR) confirmed the presence of carbon tetrachloride in the Morgan well, as well as in a second well (on property currently occupied by the Missouri Department of Transportation [MoDOT]) described as being approximately 400 ft east of the former CCC/USDA facility. The identified concentrations in these two wells were above the EPA maximum contaminant level (MCL) and the Missouri risk-based corrective action default target level (MRBCA DTL) values of 5.0 {micro}g/L for carbon tetrachloride in water used for domestic …
Date: August 16, 2010
Creator: LaFreniere, L. M. & Division, Environmental Science
System: The UNT Digital Library
Expansion of Michigan EOR Operations Using Advanced Amine Technology at a 600 MW Project Wolverine Carbon Capture and Storage Project (open access)

Expansion of Michigan EOR Operations Using Advanced Amine Technology at a 600 MW Project Wolverine Carbon Capture and Storage Project

Wolverine Power Supply Cooperative Inc, a member owned cooperative utility based in Cadillac Michigan, proposes to demonstrate the capture, beneficial utilization and storage of CO{sub 2} in the expansion of existing Enhanced Oil Recovery operations. This project is being proposed in response to the US Department of Energy Solicitation DE-FOA-0000015 Section III D, 'Large Scale Industrial CCS projects from Industrial Sources' Technology Area 1. The project will remove 1,000 metric tons per day of CO{sub 2} from the Wolverine Clean Energy Venture 600 MW CFB power plant owned and operated by WPC. CO{sub 2} from the flue gas will be captured using Hitachi's CO{sub 2} capture system and advanced amine technology. The capture system with the advanced amine-based solvent supplied by Hitachi is expected to significantly reduce the cost and energy requirements of CO{sub 2} capture compared to current technologies. The captured CO{sub 2} will be compressed and transported for Enhanced Oil Recovery and CO{sub 2} storage purposes. Enhanced Oil Recovery is a proven concept, widely used to recover otherwise inaccessible petroleum reserves. While post-combustion CO{sub 2} capture technologies have been tested at the pilot scale on coal power plant flue gas, they have not yet been demonstrated at a …
Date: June 16, 2010
Creator: Hoffman, H; kishinevsky, Y; Wu, S.; Pardini, R.; Tripp, E. & Barnes, D.
System: The UNT Digital Library
Background Radiation Survey of the Radiological/Nuclear Countermeasures Test and Evaluation Center (open access)

Background Radiation Survey of the Radiological/Nuclear Countermeasures Test and Evaluation Center

In preparation for operations at the Radiological/Nuclear Countermeasures Test and Evaluation Complex (Rad/NucCTEC), the Department of Homeland Security Domestic Nuclear Detection Office (DHS/DNDO) requested that personnel from the Remote Sensing Laboratory (RSL) conduct a survey of the present radiological conditions at the facility. The measurements consist of the exposure rate from a high-pressure ion chamber (HPIC), high-resolution spectra from a high-purity germanium (HPGe) system in an in situ configuration, and low-resolution spectra from a sodium iodide (NaI) detector in a radiation detection backpack. Measurements with these systems were collected at discrete locations within the facility. Measurements were also collected by carrying the VECTOR backpack throughout the complex to generate a map of the entire area. The area was also to be surveyed with the Kiwi (an array of eight-2-inch x 4-inch x 16-inch NaI detectors) from the Aerial Measuring Systems; however, conflicts with test preparation activities at the site prevented this from being accomplished.
Date: September 16, 2010
Creator: Okada, Colin
System: The UNT Digital Library
Lithium and Zinc Sulfide Coated Plastic Neutron Detector Test (open access)

Lithium and Zinc Sulfide Coated Plastic Neutron Detector Test

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. In addition, a few other companies have detector technologies that might be competitive in the near term as an alternative technology. Reported here are the results of tests of 6Li/ZnS(Ag)-coated scintillator paddles. This testing measured the required performance for neutron detection efficiency and gamma ray rejection capabilities of a system manufactured by Symetrica.
Date: July 16, 2010
Creator: Kouzes, Richard T. & Ely, James H.
System: The UNT Digital Library
Final Work Plan : Phase I Investigation of Potential Contamination at the Former CCC/USDA Grain Storage Facility in Montgomery City, Missouri. (open access)

Final Work Plan : Phase I Investigation of Potential Contamination at the Former CCC/USDA Grain Storage Facility in Montgomery City, Missouri.

From September 1949 until September 1966, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) leased property at the southeastern end of Montgomery City, Missouri, for the operation of a grain storage facility. During this time, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the private grain storage industry to preserve grain in their facilities. In January 2000, carbon tetrachloride was detected in a soil sample (220 {micro}g/kg) and two soil gas samples (58 {micro}g/m{sup 3} and 550 {micro}g/m{sup 3}) collected at the former CCC/USDA facility, as a result of a pre-CERCLIS site screening investigation (SSI) performed by TN & Associates, Inc., on behalf of the U.S. Environmental Protection Agency (EPA), Region VII (MoDNR 2001). In June 2001, the Missouri Department of Natural Resources (MoDNR) conducted further sampling of the soils and groundwater at the former CCC/USDA facility as part of a preliminary assessment/site inspection (PA/SI). The MoDNR confirmed the presence of carbon tetrachloride (at a maximum identified concentration of 2,810 {micro}g/kg) and chloroform (maximum 82 {micro}g/kg) in the soils and also detected carbon tetrachloride and chloroform (42.2 {micro}g/L and 58.4 {micro}g/L, respectively) in a groundwater sample collected at the former facility (MoDNR …
Date: August 16, 2010
Creator: LaFreniere, L. M. & Division, Environmental Science
System: The UNT Digital Library
Exploration of Resource and Transmission Expansion Decisions in the Western Renewable Energy Zone Initiative (open access)

Exploration of Resource and Transmission Expansion Decisions in the Western Renewable Energy Zone Initiative

Building transmission to reach renewable energy (RE) goals requires coordination among renewable developers, utilities and transmission owners, resource and transmission planners, state and federal regulators, and environmental organizations. The Western Renewable Energy Zone (WREZ) initiative brings together a diverse set of voices to develop data, tools, and a unique forum for coordinating transmission expansion in the Western Interconnection. In this report we use a new tool developed in the WREZ initiative to evaluate possible renewable resource selection and transmission expansion decisions. We evaluate these decisions under a number of alternative future scenarios centered on meeting 33% of the annual load in the Western Interconnection with new renewable resources located within WREZ-identified resource hubs. Of the renewable resources in WREZ resource hubs, and under the assumptions described in this report, our analysis finds that wind energy is the largest source of renewable energy procured to meet the 33% RE target across nearly all scenarios analyzed (38-65%). Solar energy is almost always the second largest source (14-41%). Solar exceeds wind by a small margin only when solar thermal energy is assumed to experience cost reductions relative to all other technologies. Biomass, geothermal, and hydropower are found to represent a smaller portion of …
Date: February 16, 2010
Creator: Mills, Andrew; Phadke, Amol & Wiser, Ryan
System: The UNT Digital Library
Assessment of the 3420 Building Filtered Exhaust Stack Sampling Probe Location (open access)

Assessment of the 3420 Building Filtered Exhaust Stack Sampling Probe Location

Pacific Northwest National Laboratory performed several tests in the exhaust air discharge from the new 3420 Building Filtered Exhaust Stack to determine whether the air sampling probe for emissions monitoring for radionuclides is acceptable. The method followed involved adopting the results of a previously performed test series from a system with a similar configuration, followed by several tests on the actual system to verify the applicability of the previously performed tests. The qualification criteria for these types of stacks include metrics concerning 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity tracer particle concentration.
Date: July 16, 2010
Creator: Glissmeyer, John A. & Flaherty, Julia E.
System: The UNT Digital Library
Use Patterns of LED Flashlights in Kenya and a One-Year Cost Analysis of Flashlight Ownership (open access)

Use Patterns of LED Flashlights in Kenya and a One-Year Cost Analysis of Flashlight Ownership

Flashlight usage is widespread across much of sub-Saharan Africa.1 In Kenya in particular, over half of all households report owning a flashlight (Kamfor, 2002). Aside from household use, flashlights are also widely used to perform income-earning jobs in Kenya. Lumina Research Note No.4, the first report in this series documenting flashlight use in Kenya, highlights flashlight use patterns of night watchmen and bicycle taxi drivers. Both of these are occupations that rely on the use of flashlights on a nightly basis (Tracy et al., 2009). Also highlighted by Research Note No.4, flashlight users in Kenya have reported being highly dissatisfied with the quality of the low-cost LED flashlights that are available, and they identify several reoccurring problems they have faced as flashlight end-users (Tracy et al., 2009). The fact that there exists a substantial dependency upon flashlights in Kenya and that users are disgruntled with the available products suggests reasons for concern about flashlight quality. This concern is present despite two recent technological transitions in the flashlight market. First, LED technology has quickly emerged as the dominant source of portable lighting in Kenya, outpacing incandescent flashlights (Johnstone et al., 2009). LED technology has the potential to provide efficiency and performance …
Date: February 16, 2010
Creator: Tracy, Jennifer; Jacobson, Arne & Mills, Evan
System: The UNT Digital Library
Bulk Data Movement for Climate Dataset: Efficient Data Transfer Management with Dynamic Transfer Adjustment (open access)

Bulk Data Movement for Climate Dataset: Efficient Data Transfer Management with Dynamic Transfer Adjustment

Many scientific applications and experiments, such as high energy and nuclear physics, astrophysics, climate observation and modeling, combustion, nano-scale material sciences, and computational biology, generate extreme volumes of data with a large number of files. These data sources are distributed among national and international data repositories, and are shared by large numbers of geographically distributed scientists. A large portion of data is frequently accessed, and a large volume of data is moved from one place to another for analysis and storage. One challenging issue in such efforts is the limited network capacity for moving large datasets to explore and manage. The Bulk Data Mover (BDM), a data transfer management tool in the Earth System Grid (ESG) community, has been managing the massive dataset transfers efficiently with the pre-configured transfer properties in the environment where the network bandwidth is limited. Dynamic transfer adjustment was studied to enhance the BDM to handle significant end-to-end performance changes in the dynamic network environment as well as to control the data transfers for the desired transfer performance. We describe the results from the BDM transfer management for the climate datasets. We also describe the transfer estimation model and results from the dynamic transfer adjustment.
Date: July 16, 2010
Creator: Sim, Alexander; Balman, Mehmet; Williams, Dean; Shoshani, Arie & Natarajan, Vijaya
System: The UNT Digital Library
Assessment of the 3410 Building Filtered Exhaust Stack Sampling Probe Location (open access)

Assessment of the 3410 Building Filtered Exhaust Stack Sampling Probe Location

Pacific Northwest National Laboratory performed several tests in the exhaust air discharge from the new 3410 Building Filtered Exhaust Stack to determine whether the air sampling probe for emissions monitoring for radionuclides is acceptable. The method followed involved adopting the results of a previously performed test series from a system with a similar configuration, followed by several tests on the actual system to verify the applicability of the previously performed tests. The qualification criteria for these types of stacks include metrics concerning 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity tracer particle concentration.
Date: July 16, 2010
Creator: Glissmeyer, John A. & Flaherty, Julia E.
System: The UNT Digital Library
Illinois Department of Public Health H1N1/A Pandemic Communications Evaluation Survey. (open access)

Illinois Department of Public Health H1N1/A Pandemic Communications Evaluation Survey.

Because of heightened media coverage, a 24-hour news cycle and the potential miscommunication of health messages across all levels of government during the onset of the H1N1 influenza outbreak in spring 2009, the Illinois Department of Public Health (IDPH) decided to evaluate its H1N1 influenza A communications system. IDPH wanted to confirm its disease information and instructions were helping stakeholders prepare for and respond to a novel influenza outbreak. In addition, the time commitment involved in preparing, issuing, monitoring, updating, and responding to H1N1 federal guidelines/updates and media stories became a heavy burden for IDPH staff. The process and results of the H1N1 messaging survey represent a best practice that other health departments and emergency management agencies can replicate to improve coordination efforts with stakeholder groups during both emergency preparedness and response phases. Importantly, the H1N1 survey confirmed IDPH's messages were influencing stakeholders decisions to activate their pandemic plans and initiate response operations. While there was some dissatisfaction with IDPH's delivery of information and communication tools, such as the fax system, this report should demonstrate to IDPH that its core partners believe it has the ability and expertise to issue timely and accurate instructions that can help them respond to …
Date: September 16, 2010
Creator: Walsh, D. & Sciences, Decision and Information
System: The UNT Digital Library
Ready, set...go! (open access)

Ready, set...go!

The objectives of this paper are: (1) Discuss organizational readiness for changes in an ergonomics program or intervention; (2) Assessing organizational readiness; (3) Benefits and challenges of change; and (4) Case studies of ergonomic programs that were 'not ready' and 'ready'.
Date: June 16, 2010
Creator: Alexandre, Melanie
System: The UNT Digital Library
Activation Layer Stabilization of High Polarization Photocathodes in Sub-Optimal RF Gun Environments (open access)

Activation Layer Stabilization of High Polarization Photocathodes in Sub-Optimal RF Gun Environments

Specific activation recipes for bulk, 100 nm thick MBE grown and high polarization III-V photocathode material have been developed which mitigate the effects of exposure to background gasses. Lifetime data using four representative gasses were acquired for bulk GaAs, 100 nm unstrained GaAs and strained superlattice GaAs/GaAsP, all activated both with Cs and then Cs and Li (bi-alkali). Each photoemitter showed marked resilience improvement when activated using the bi-alkali recipe compared to the standard single alkali recipe. A dual alkali activation system at SLAC was constructed, baked and commissioned with the purpose of performing spin-polarization measurements on electrons emitted from the bi-alkali activated surfaces. An end station at SSRL was configured with the required sources for energy resolved photoemission measurements on the bi-alkali activated and CO2 dosed surfaces. The bi-alkali recipes were successfully implemented at SLAC/SSRL. Measurements at SLAC of the photoelectron spin-polarization from the modified activation surface showed no sign of a change in value compared to the standard activated material, i.e., no ill effects. Analysis of photoemission data indicates that the addition of Li to the activation layer results in a multi-layer structure. The presence of Li in the activation layer also acts as an inhibitor to CO2 …
Date: November 16, 2010
Creator: Mulhollan, Gregory A.
System: The UNT Digital Library
PASSIVATION LAYER STABILITY OF A METALLIC ALLOY WASTE FORM (open access)

PASSIVATION LAYER STABILITY OF A METALLIC ALLOY WASTE FORM

Alloy waste form development under the Waste Forms Campaign of the DOE-NE Fuel Cycle Research & Development program includes the process development and characterization of an alloy system to incorporate metal species from the waste streams generated during nuclear fuel recycling. This report describes the tests and results from the FY10 activities to further investigate an Fe-based waste form that uses 300-series stainless steel as the base alloy in an induction furnace melt process to incorporate the waste species from a closed nuclear fuel recycle separations scheme. This report is focused on the initial activities to investigate the formation of oxyhydroxide layer(s) that would be expected to develop on the Fe-based waste form as it corrodes under aqueous repository conditions. Corrosion tests were used to evaluate the stability of the layer(s) that can act as a passivation layer against further corrosion and would affect waste form durability in a disposal environment.
Date: August 16, 2010
Creator: Williamson, M.; Mickalonis, J.; Fisher, D. & Sindelar, R.
System: The UNT Digital Library
ConocoPhillips Sweeny IGCC/CCS Project (open access)

ConocoPhillips Sweeny IGCC/CCS Project

Under its Industrial Carbon Capture and Sequestration (ICCS) Program, the United States (U.S.) Department of Energy (DOE) selected ConocoPhillips Company (ConocoPhillips) to receive funding through the American Recovery and Reinvestment Act (ARRA) of 2009 for the proposed Sweeny Integrated Gasification Combined Cycle (IGCC)/Carbon Capture and Storage (CCS) Project (Project) to be located in Brazoria County, Texas. Under the program, the DOE is partnering with industry to demonstrate the commercial viability and operational readiness of technologies that would capture carbon dioxide (CO{sub 2}) emissions from industrial sources and either sequester those emissions, or beneficially reuse them. The primary objective of the proposed Project was to demonstrate the efficacy of advanced technologies that capture CO{sub 2} from a large industrial source and store the CO{sub 2} in underground formations, while achieving a successful business venture for the entity (entities) involved. The Project would capture 85% of the CO{sub 2} produced from a petroleum coke (petcoke) fed, 703 MWnet (1,000 MWgross) IGCC power plant, using the ConocoPhillips (COP) proprietary and commercially proven E-Gas{trademark} gasification technology, at the existing 247,000 barrel per day COP Sweeny Refinery. In addition, a number of other commercially available technologies would be integrated into a conventional IGCC Plant in …
Date: June 16, 2010
Creator: Talarico, Paul; Sugg, Charles; Hren, Thomas; Branch, Lauri; Garcia, Joseph; Rezigh, Alan et al.
System: The UNT Digital Library
Cracking Behavior and Microstructure of Austenitic Stainless Steels and Alloy 690 Irradiated in BOR-60 Reactor, Phase I. (open access)

Cracking Behavior and Microstructure of Austenitic Stainless Steels and Alloy 690 Irradiated in BOR-60 Reactor, Phase I.

Cracking behavior of stainless steels specimens irradiated in the BOR-60 at about 320 C is studied. The primary objective of this research is to improve the mechanistic understanding of irradiation-assisted stress corrosion cracking (IASCC) of core internal components under conditions relevant to pressurized water reactors. The current report covers several baseline tests in air, a comparison study in high-dissolved-oxygen environment, and TEM characterization of irradiation defect structure. Slow strain rate tensile (SSRT) tests were conducted in air and in high-dissolved-oxygen (DO) water with selected 5- and 10-dpa specimens. The results in high-DO water were compared with those from earlier tests with identical materials irradiated in the Halden reactor to a similar dose. The SSRT tests produced similar results among different materials irradiated in the Halden and BOR-60 reactors. However, the post-irradiation strength for the BOR-60 specimens was consistently lower than that of the corresponding Halden specimens. The elongation of the BOR-60 specimens was also greater than that of their Halden specimens. Intergranular cracking in high-DO water was consistent for most of the tested materials in the Halden and BOR-60 irradiations. Nonetheless, the BOR-60 irradiation was somewhat less effective in stimulating IG fracture among the tested materials. Microstructural characterization was also …
Date: February 16, 2010
Creator: Chen, Y.; Chopra, O. K.; Soppet, W. K.; Shack, W. J.; Yang, Y.; Allen, T. R. et al.
System: The UNT Digital Library
Performance Properties of Saltstone Produced Using SWPF Stimulants (open access)

Performance Properties of Saltstone Produced Using SWPF Stimulants

The overwhelming majority of waste to be immobilized at the Saltstone Production Facility will come from the waste stream exiting the Salt Waste Processing Facility (SWPF). These SWPF batches are salt solutions that result from pretreatment of the High Level Waste (HLW) supernate by an Actinide Removal Process followed by Caustic Side Solvent Extraction. The concentration of aluminate within these streams will vary and be determined by (1) the concentration in the incoming salt waste stream, (2) the degree of aluminum leaching from the HLW, (3) the method for introducing the aluminate into the waste stream (continuous or batch) and (4) and any operational or regulatory limitations. The overall Performance Assessment outcome for the Saltstone Disposal Facility will depend significantly on the performance properties of the SWPF Saltstone grouts. This report identifies and quantifies, when possible, those factors that drive the performance properties of the projected SWPF grouts. Previous work has identified aluminate concentration in the salt waste stream as a key factor in determining performance. Consequently, significant variation in the aluminate concentration to a maximum level of 0.65 M was investigated in this report. The SWPF baseline grout is a mix with a 0.60 water to cementitious ratio and …
Date: February 16, 2010
Creator: Harbour, J. & Edwards, T.
System: The UNT Digital Library
EM-31 RETRIEVAL KNOWLEDGE CENTER MEETING REPORT: MOBILIZE AND DISLODGE TANK WASTE HEELS (open access)

EM-31 RETRIEVAL KNOWLEDGE CENTER MEETING REPORT: MOBILIZE AND DISLODGE TANK WASTE HEELS

The Retrieval Knowledge Center sponsored a meeting in June 2009 to review challenges and gaps to retrieval of tank waste heels. The facilitated meeting was held at the Savannah River Research Campus with personnel broadly representing tank waste retrieval knowledge at Hanford, Savannah River, Idaho, and Oak Ridge. This document captures the results of this meeting. In summary, it was agreed that the challenges to retrieval of tank waste heels fell into two broad categories: (1) mechanical heel waste retrieval methodologies and equipment and (2) understanding and manipulating the heel waste (physical, radiological, and chemical characteristics) to support retrieval options and subsequent processing. Recent successes and lessons from deployments of the Sand and Salt Mantis vehicles as well as retrieval of C-Area tanks at Hanford were reviewed. Suggestions to address existing retrieval approaches that utilize a limited set of tools and techniques are included in this report. The meeting found that there had been very little effort to improve or integrate the multiple proven or new techniques and tools available into a menu of available methods for rapid insertion into baselines. It is recommended that focused developmental efforts continue in the two areas underway (low-level mixing evaluation and pumping slurries …
Date: February 16, 2010
Creator: Fellinger, A.
System: The UNT Digital Library
Assessment of the Proposed INTEC CPP 666 Stack Monitoring Site for Compliance with ANSI/HPS N13.1 1999 (open access)

Assessment of the Proposed INTEC CPP 666 Stack Monitoring Site for Compliance with ANSI/HPS N13.1 1999

This document reports on a series of tests to determine whether the proposed new location for air sampling probes in the CPP-666 heating, ventilation and air conditioning (HVAC) exhaust duct would meet the applicable regulatory criteria regarding the placement of an air sampling probe. Federal regulations( ) require that a sampling probe be located in the exhaust stack according to the criteria of the American National Standards Institute/Health Physical Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that is representative of the effluent stream.
Date: February 16, 2010
Creator: Glissmeyer, John A. & Flaherty, Julia E.
System: The UNT Digital Library
Random Number Generation for Petascale Quantum Monte Carlo (open access)

Random Number Generation for Petascale Quantum Monte Carlo

The quality of random number generators can affect the results of Monte Carlo computations, especially when a large number of random numbers are consumed. Furthermore, correlations present between different random number streams in a parallel computation can further affect the results. The SPRNG software, which the author had developed earlier, has pseudo-random number generators (PRNGs) capable of producing large numbers of streams with large periods. However, they had been empirically tested on only thousand streams earlier. In the work summarized here, we tested the SPRNG generators with over a hundred thousand streams, involving over 10^14 random numbers per test, on some tests. We also tested the popular Mersenne Twister. We believe that these are the largest tests of PRNGs, both in terms of the numbers of streams tested and the number of random numbers tested. We observed defects in some of these generators, including the Mersenne Twister, while a few generators appeared to perform well. We also corrected an error in the implementation of one of the SPRNG generators.
Date: March 16, 2010
Creator: Srinivasan, Ashok
System: The UNT Digital Library
Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons (open access)

Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary …
Date: March 16, 2010
Creator: Baisden, Patricia; Bauge, Eric; Ferguson, James; Gilliam, David; Granier, Thierry; Jeanloz, Raymond et al.
System: The UNT Digital Library
Evaluation of LLNL BSL-3 Maximum Credible Event Potential Consequence to the General Population and Surrounding Environment (open access)