Resource Type

PIES Applications to NCSX (open access)

PIES Applications to NCSX

The purpose of the research presented here is two fold. We present preliminary results for the assessment of flux surface quality for a candidate configuration for the National Compact Stellarator Experiment (NCSX) experiment. We also present preliminary results of the assessment of our 3-D MHD tools, PIES[1] and VMEC[2]. We first illustrate the flux surface quality in C82 by showing PIES results for several snapshots in the evolution of the plasma from 0% beta to 3.5% beta. C82 is a quasi-axisymmetric candidate configuration for the NCSX experiment. Next, as part of our effort to qualify the PIES code for current carrying stellarators, we present results for a W7-AS experimental shot. Lastly, we show evidence from the PIES code that the equilibrium produced by VMEC violate the Hamada condition.
Date: October 1, 1999
Creator: Reiman, A.; Monticello, D. & Hirshman, S.
System: The UNT Digital Library
Kinetics of Reaction Between Plutonium Dioxide and Water at 25 C to 350 C: Formation and Properties of the PuO{sub 2+X} Phase (open access)

Kinetics of Reaction Between Plutonium Dioxide and Water at 25 C to 350 C: Formation and Properties of the PuO{sub 2+X} Phase

Results of microbalance, pressure-volume-temperature, and mass spectrometric measurements show that a higher oxide of plutonium, PuO{sub 2+x}, and hydrogen are formed by reaction of plutonium dioxide with water at 25 C to 350 C. PuO{sub 2+x} has an intense green color consistent with the presence of Pu(VI). An oxide composition in excess of PuO{sub 2.25} is identified, but the maximum value of x is undefined. Reaction rates derived from linear mass-time and pressure-time data are described by an Arrhenius relationship that yields an activation energy of 9.4 {+-} 0.6 kcal/mol for the PuO{sub 2} + H{sub 2}O reaction. X-ray diffraction data for PuO{sub 2+x} shows that the oxide has a fluorite-related structure consistent with substitution of Pu(VI) on cationic lattice sites and accommodation of additional oxygen on interstitial sites. The cubic lattice parameter has a low, but well-defined, linear dependence on the O:Pu ratio, suggesting that PuO{sub 2+x} forms as a continuous solid solution. The failure of earlier attempts to prepare higher oxides of plutonium is attributed to slow oxidation kinetics and insensitivity of diagnostic techniques. Similarities of the PuO{sub 2+x} and UO{sub 2+x} phase are examined and relevance of the results to plutonium technology and environmental issues is discussed.
Date: May 1, 1999
Creator: Morales, Luis A.; Haschke, John M. & Allen, Thomas H.
System: The UNT Digital Library
Analytical Benchmark Test Set for Criticality Code Verification (open access)

Analytical Benchmark Test Set for Criticality Code Verification

A number of published numerical solutions to analytic eigenvalue (k{sub eff}) and eigenfunction equations are summarized for the purpose of creating a criticality verification benchmark test set. The 75-problem test set allows the user to verify the correctness of a criticality code for infinite medium and simple geometries in one- and two-energy groups, one- and two-media, and both isotropic and anisotropic neutron scattering. The problem specifications will produce both k{sub eff} = 1 and the quoted k{sub {infinity}} to at least five decimal places. Additional uses of the test set for code verification are also discussed. A list of 45 references and an appendix with k{sub {infinity}} derivations is also included.
Date: July 1, 1999
Creator: Sood, Avneet; Parsons, D. K. & Forster, R. A.
System: The UNT Digital Library
Development of an Integrated Global Energy Model (open access)

Development of an Integrated Global Energy Model

The primary objective of this research was to develop a forefront analysis tool for application to enhance understanding of long-term, global, nuclear-energy and nuclear-material futures. To this end, an existing economics-energy-environmental (E{sup 3}) model was adopted, modified, and elaborated to examine this problem in a multi-regional (13), long-term ({approximately}2,100) context. The E{sup 3} model so developed was applied to create a Los Alamos presence in this E{sup 3} area through ''niche analyses'' that provide input to the formulation of policies dealing with and shaping of nuclear-energy and nuclear-materials futures. Results from analyses using the E{sup 3} model have been presented at a variety of national and international conferences and workshops. Through use of the E{sup 3} model Los Alamos was afforded the opportunity to participate in a multi-national E{sup 3} study team that is examining a range of global, long-term nuclear issues under the auspices of the IAEA during the 1998-99 period . Finally, the E{sup 3} model developed under this LDRD project is being used as an important component in more recent Nuclear Material Management Systems (NMMS) project.
Date: July 8, 1999
Creator: Krakowski, Robert A.
System: The UNT Digital Library
An assessment of the MCNP4C weight window (open access)

An assessment of the MCNP4C weight window

A new, enhanced weight window generator suite has been developed for MCNP version 4C. The new generator correctly estimates importances in either a user-specified, geometry-independent, orthogonal grid or in MCNP geometric cells. The geometry-independent option alleviates the need to subdivide the MCNP cell geometry for variance reduction purposes. In addition, the new suite corrects several pathologies in the existing MCNP weight window generator. The new generator is applied in a set of five variance reduction problems. The improved generator is compared with the weight window generator applied in MCNP4B. The benefits of the new methodology are highlighted, along with a description of its limitations. The authors also provide recommendations for utilization of the weight window generator.
Date: December 1, 1999
Creator: Culbertson, Christopher N. & Hendricks, John S.
System: The UNT Digital Library
Spectral measurements in critical assemblies: MCNP specifications and calculated results (open access)

Spectral measurements in critical assemblies: MCNP specifications and calculated results

Recently, a suite of 86 criticality benchmarks for the Monte Carlo N-Particle (MCNP) transport code was developed, and the results of testing the ENDF/B-V and ENDF/B-VI data (through Release 2) were published. In addition to the standard k{sub eff} measurements, other experimental measurements were performed on a number of these benchmark assemblies. In particular, the Cross Section Evaluation Working Group (CSEWG) specifications contain experimental data for neutron leakage and central-flux measurements, central-fission ratio measurements, and activation ratio measurements. Additionally, there exists another set of fission reaction-rate measurements performed at the National Institute of Standards and Technology (NIST) utilizing a {sup 252}Cf source. This report will describe the leakage and central-flux measurements and show a comparison of experimental data to MCNP simulations performed using the ENDF/B-V and B-VI (Release 2) data libraries. Central-fission and activation reaction-rate measurements will be described, and the comparison of experimental data to MCNP simulations using available data libraries for each reaction of interest will be presented. Finally, the NIST fission reaction-rate measurements will be described. A comparison of MCNP results published previously with the current MCNP simulations will be presented for the NIST measurements, and a comparison of the current MCNP simulations to the experimental measurements …
Date: December 1, 1999
Creator: Frankle, Stephanie C. & Briesmeister, Judith F.
System: The UNT Digital Library
Laboratory Directed Research and Development FY 1998 Progress Report (open access)

Laboratory Directed Research and Development FY 1998 Progress Report

This is the FY 1998 Progress Report for the Laboratory Directed Research and Development (LDRD) Program at Los Alamos National Laboratory. It gives an overview of the LDRD Program, summarizes work done on individual research projects, relates the projects to major Laboratory program sponsors, and provides an index to the principle investigators. Project summaries are grouped by their LDRD component: Competency Development, Program Development, and Individual Projects. Within each component, they are further grouped into nine technical categories: (1) materials science, (2) chemistry, (3) mathematics and computational science, (4) atomic, molecular, optical, and plasma physics, fluids, and particle beams, (5) engineering science, (6) instrumentation and diagnostics, (7) geoscience, space science, and astrophysics, (8) nuclear and particle physics, and (9) bioscience.
Date: April 1, 1999
Creator: Vigil, John & Wheeler, Kyle
System: The UNT Digital Library
Baseline Concentrations of Radionuclides and Trace Elements in Soils and Vegetation around the DARHT Facility: Construction Phase (1998) (open access)

Baseline Concentrations of Radionuclides and Trace Elements in Soils and Vegetation around the DARHT Facility: Construction Phase (1998)

The Mitigation Action Plan for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory mandates the establishment of baseline concentrations for potential environmental contaminants. To this end, concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, and {sup tot}U and Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl were determined in surface and subsurface soils, sediments, and vegetation (overstory and understory) around the DARHT facility during the construction phase in 1998 (this is the third of a four year baseline study). Also, volatile (VOC) and semivolatile (SVOC) organic compounds were measured in soils and sediments. Most radionuclides and trace metals in soil, sediment, and vegetation were similar to past years at DARHT and were within regional background concentrations. Exceptions were concentrations of {sup 90}Sr, Be, Ba, and total U in some samples--these elements exceeded upper limit regional background concentrations (e.g., >mean plus two std dev). No VOCs and very few SVOCs were detected in soils and sediments at DARHT. Mean ({+-} std dev) radionuclide and trace element concentrations measured in soil, sediment, and vegetation summarized over a three-year period (construction phase) are summarized.
Date: December 1, 1999
Creator: Fresquez, P. R.; Ebinger, M. H.; Haagenstad, H. T. & L. Naranjo, Jr.
System: The UNT Digital Library
Earth and environmental sciences annual report 1998 (open access)

Earth and environmental sciences annual report 1998

Lawrence Livermore National Laboratory (LLNL) provides broad-based, integrated scientific and engineering capabilities to address some of the nation's top national security and environmental priorities. National security priorities are to ensure the safety and reliability of the U.S. nuclear weapons stockpile and to counter the spread of weapons of mass destruction; environmental priorities are to keep our environment healthy for the long term and to assess the consequences of environmental change. The Earth and Environmental Sciences (E&ES) Directorate at LLNL pursues applied and basic research across many disciplines to advance the technologies needed to address these national concerns. Our current work focuses on: Storage and ultimate disposition of U.S. spent reactor fuel and other nuclear materials; Assessment of the current global climate and simulation of future changes caused by humans or nature; Development of broadly applicable technologies for environmental remediation and risk reduction; Tools to support U.S. goals for verifying the international Comprehensive Nuclear-Test-Ban Treaty; subcritical tests for stockpile stewardship; Real-time assessments of the health and environmental consequences of atmospheric releases of radioactive or other hazardous materials; and Basic science research that investigates fundamental physical and chemical properties of interest to these applied research programs. For each of these areas we …
Date: May 18, 1999
Creator: Younker, L
System: The UNT Digital Library
Geologic and Engineering Characterization of East Ford Field, Reeves County, Texas (open access)

Geologic and Engineering Characterization of East Ford Field, Reeves County, Texas

The objective of this Class III project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through geologically based field development. The project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Oral Petco, Inc., as the East Ford unit: it contained an estimated 18.4 million barrels (MMbbl) of original oil in place.
Date: August 16, 1999
Creator: Dutton, Shirley P.; Flanders, William A.; Guzman, Jose I. & Zirczy, Helena
System: The UNT Digital Library
Salmon Site Remedial Investigation Report, Main Body (open access)

Salmon Site Remedial Investigation Report, Main Body

This Salmon Site Remedial Investigation Report provides the results of activities initiated by the U.S. Department of Energy (DOE) to determine if contamination at the Salmon Site poses a current or future risk to human health and the environment. These results were used to develop and evaluate a range of risk-based remedial alternatives. Located in Lamar County, Mississippi, the Salmon Site was used by the U.S. Atomic Energy Commission (predecessor to the DOE) between 1964 and 1970 for two nuclear and two gas explosions conducted deep underground in a salt dome. The testing resulted in the release of radionuclides into the salt dome. During reentry drilling and other site activities, liquid and solid wastes containing radioactivity were generated resulting in surface soil and groundwater contamination. Most of the waste and contaminated soil and water were disposed of in 1993 during site restoration either in the cavities left by the tests or in an injection well. Other radioactive wastes were transported to the Nevada Test Site for disposal. Nonradioactive wastes were disposed of in pits at the site and capped with clean soil and graded. The preliminary investigation showed residual contamination in the Surface Ground Zero mud pits below the water …
Date: September 1, 1999
Creator: United States. Department of Energy. Nevada Operations Office.
System: The UNT Digital Library
Data Decision Analysis: Project Shoal (open access)

Data Decision Analysis: Project Shoal

The purpose of this study was to determine the most appropriate field activities in terms of reducing the uncertainty in the groundwater flow and transport model at the Project Shoal area. The data decision analysis relied on well-known tools of statistics and uncertainty analysis. This procedure identified nine parameters that were deemed uncertain. These included effective porosity, hydraulic head, surface recharge, hydraulic conductivity, fracture correlation scale, fracture orientation, dip angle, dissolution rate of radionuclides from the puddle glass, and the retardation coefficient, which describes the sorption characteristics. The parameter uncertainty was described by assigning prior distributions for each of these parameters. Next, the various field activities were identified that would provide additional information on these parameters. Each of the field activities was evaluated by an expert panel to estimate posterior distribution of the parameters assuming a field activity was performed. The posterior distributions describe the ability of the field activity to estimate the true value of the nine parameters. Monte Carlo techniques were used to determine the current uncertainty, the reduction of uncertainty if a single parameter was known with certainty, and the reduction of uncertainty expected from each field activity on the model predictions. The mean breakthrough time to …
Date: January 1, 1999
Creator: Forsgren, Frank; Pohll, Greg & Tracy, John
System: The UNT Digital Library
SUBAQUEOUS DISPOSAL OF MILL TAILINGS (open access)

SUBAQUEOUS DISPOSAL OF MILL TAILINGS

A study of mill tailings and sulfide minerals was carried out in order to understand their behavior under subaqueous conditions. A series of electrochemical experiments, namely, cyclic voltammetry, electrochemical impedance spectroscopy and galvanic coupling tests were carried out in artificial seawater and in pH 6.8 buffer solutions with chloride and ferric salts. Two mill tailings samples, one from the Kensington Mine, Alaska, and the other from the Holden Mine, Washington, were studied along with pyrite, galena, chalcopyrite and copper-activated sphalerite. SEM analysis of mill tailings revealed absence of sulfide minerals from the Kensington Mine mill tailings, whereas the Holden Mine mill tailings contained approximately 8% pyrite and 1% sphalerite. In order to conduct electrochemical tests, carbon matrix composite (CMC) electrodes of mill tailings, pyrite and galena were prepared and their feasibility was established by conducting a series of cyclic voltammetry tests. The cyclic voltammetry experiments carried out in artificial seawater and pH 6.8 buffer with chloride salts showed that chloride ions play an important role in the redox processes of sulfide minerals. For pyrite and galena, peaks were observed for the formation of chloride complexes, whereas pitting behavior was observed for the CMC electrodes of the Kensington Mine mill tailings. …
Date: September 3, 1999
Creator: Mendiratta, Neeraj K.; Yoon, Roe-Hoan & Richardson, Paul
System: The UNT Digital Library
Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management (open access)

Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

The objectives of this quarterly report was to summarize the work conducted under each task during the reporting period April - June 1998 and to report all technical data and findings as specified in the ''Federal Assistance Reporting Checklist''. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology.
Date: November 9, 1999
Creator: Koerner, Roy; Clarke, Don & Walker, Scott
System: The UNT Digital Library
Low frequency RF current drive. Final report, January 1, 1988--May 31, 1997 (open access)

Low frequency RF current drive. Final report, January 1, 1988--May 31, 1997

This report starts with a summary of research done on the Phaedrus Tandom Mirror concept and how this research led to the design and construction of the Phaedrus-T Tokamak. Next it gives a more detailed description of the results from the last four years of research, which include the following areas: (1) first experimental demonstration of AWCD (Alfven Wave Current Drive); (2) current drive location and loop voltage response; (3) trapping and current drive efficiency; and (4) reflectometry.
Date: May 1, 1999
Creator: Hershkowitz, N.
System: The UNT Digital Library
Reactions of plutonium dioxide with water and oxygen-hydrogen mixtures: Mechanisms for corrosion of uranium and plutonium (open access)

Reactions of plutonium dioxide with water and oxygen-hydrogen mixtures: Mechanisms for corrosion of uranium and plutonium

Investigation of the interactions of plutonium dioxide with water vapor and with an oxygen-hydrogen mixture show that the oxide is both chemically reactive and catalytically active. Correspondence of the chemical behavior with that for oxidation of uranium in moist air suggests that similar catalytic processes participate in the mechanism of moisture-enhanced corrosion of uranium and plutonium. Evaluation of chemical and kinetic data for corrosion of the metals leads to a comprehensive mechanism for corrosion in dry air, water vapor, and moist air. Results are applied in confirming that the corrosion rate of Pu in water vapor decreases sharply between 100 and 200 degrees C.
Date: June 18, 1999
Creator: Haschke, John M.; Allen, Thomas H. & Morales, Luis A.
System: The UNT Digital Library
Life Sciences Division progress report for CYs 1997-1998 [Oak Ridge National Laboratory] (open access)

Life Sciences Division progress report for CYs 1997-1998 [Oak Ridge National Laboratory]

This is the first formal progress report issued by the ORNL Life Sciences Division. It covers the period from February 1997 through December 1998, which has been critical in the formation of our new division. The legacy of 50 years of excellence in biological research at ORNL has been an important driver for everyone in the division to do their part so that this new research division can realize the potential it has to make seminal contributions to the life sciences for years to come. This reporting period is characterized by intense assessment and planning efforts. They included thorough scrutiny of our strengths and weaknesses, analyses of our situation with respect to comparative research organizations, and identification of major thrust areas leading to core research efforts that take advantage of our special facilities and expertise. Our goal is to develop significant research and development (R&D) programs in selected important areas to which we can make significant contributions by combining our distinctive expertise and resources in the biological sciences with those in the physical, engineering, and computational sciences. Significant facilities in mouse genomics, mass spectrometry, neutron science, bioanalytical technologies, and high performance computing are critical to the success of our programs. …
Date: June 1, 1999
Creator: Mann, Reinhold C.
System: The UNT Digital Library
AGS EXPERIMENTS IN NUCLEAR/QCD PHYSICS AT MEDIUM ENERGIES 1988-2000. (open access)

AGS EXPERIMENTS IN NUCLEAR/QCD PHYSICS AT MEDIUM ENERGIES 1988-2000.

None
Date: July 1, 1999
Creator: LO PRESTI,P.
System: The UNT Digital Library
Environmental Compliance for Oil and Gas Exploration and Production (open access)

Environmental Compliance for Oil and Gas Exploration and Production

The Appalachian/Illinois Basin Directors is a group devoted to increasing communication among the state oil and gas regulatory agencies within the Appalachian and Illinois Basin producing region. The group is comprised of representatives from the oil and gas regulatory agencies from states in the basin (Attachment A). The directors met to discuss regulatory issues common to the area, organize workshops and seminars to meet the training needs of agencies dealing with the uniqueness of their producing region and perform other business pertinent to this area of oil and gas producing states. The emphasis of the coordinated work was a wide range of topics related to environmental compliance for natural gas and oil exploration and production.
Date: October 26, 1999
Creator: Hansen, Christine
System: The UNT Digital Library
Hawaiian Monk Seal Epidemiology Plan: Health Assessment and Disease Status Studies (open access)

Hawaiian Monk Seal Epidemiology Plan: Health Assessment and Disease Status Studies

The following document provides a framework for incorporation of health and information to enhance recovery of the Hawaiian monk seal.
Date: October 1999
Creator: Aguirre, A. Alonso; Reif, John S. & Antonelis, George A.
System: The UNT Digital Library
PETROLEUM RESIDUA SOLUBILITY PARAMETER/POLARITY MAP: STABILITY STUDIES OF RESIDUA PYROLYSIS (open access)

PETROLEUM RESIDUA SOLUBILITY PARAMETER/POLARITY MAP: STABILITY STUDIES OF RESIDUA PYROLYSIS

A new molecular weight/polarity map based on the Scatchard-Hildebrand solubility equation has been developed for petroleum residua. A series of extractions are performed with solvents of increasing solubility parameter, and the fractions are analyzed by vapor pressure osmometry for number average molecular weight and by analytical-scale size exclusion chromatography for molecular weight spread. Work was performed for a heavy oil material subjected to three increasing severities of thermal treatment prior to and through the onset of coke formation. The results are diagnostic of the layers of solvations by resin-type molecules around a central asphaltene core. Two additional stability diagnostic methods were also used. These were the Heithaus titration ''P-index'' and Gaestel ''G'' index, which have been applied to paving asphalts for decades. The Heithaus titration involves the titration of three toluene solutions of a residuum at three concentrations with a poor solvent, such as isooctane, to the point of asphaltene flocculation. In the present work, the significance of the data are developed in terms of the Hildebrand solubility parameter. The Heithaus results are combined with data from the new molecular weight/polarity map. The solubility parameters for the toluene-soluble asphaltene components are measured, and the solubility parameters of the maltenes can …
Date: April 30, 1999
Creator: Schabron, John F.; Pauli, A. Troy & Joseph F. Rovani, Jr.
System: The UNT Digital Library
Slimhole Handbook: Procedures and Recommendations for Slimhole Drilling and Testing in Geothermal Exploration (open access)

Slimhole Handbook: Procedures and Recommendations for Slimhole Drilling and Testing in Geothermal Exploration

None
Date: October 1, 1999
Creator: Finger, John T.; Combs, Jim; Goranson, Colin; Hickox, Charles; Jacobson, Ronald D. & Polk, Gene
System: The UNT Digital Library
Diffusive Barrier and Getter Under Waste Packages VA Reference Design Feature Evaluations (open access)

Diffusive Barrier and Getter Under Waste Packages VA Reference Design Feature Evaluations

This technical document evaluates those aspects of the diffusive barrier and getter features which have the potential for enhancing the performance of the Viability Assessment Reference Design and are also directly related to the key attributes for the repository safety strategy of that design. The effects of advection, hydrodynamic dispersion, and diffusion on the radionuclide migration rates through the diffusive barrier were determined through the application of the one-dimensional, advection/dispersion/diffusion equation. The results showed that because advective flow described by the advection-dispersion equation dominates, the diffusive barrier feature alone would not be effective in retarding migration of radiocuclides. However, if the diffusive barrier were combined with one or more features that reduced the potential for advection, then transport of radionuclides would be dominated by diffusion and their migration from the EBS would be impeded. Apatite was chosen as the getter material used for this report. Two getter configurations were developed, Case 1 and Case 2. As in the evaluation of the diffusive barrier, the effects of advection, hydrodynamic dispersion, and diffusion on the migration of radionuclides through the getter are evaluated. However, in addition to these mechanisms, the one-dimensional advection/dispersion/diffusion model is modified to include the effect of sorption on …
Date: May 24, 1999
Creator: MacNeil, K.
System: The UNT Digital Library