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.
Object Type: Report
System: The UNT Digital Library
Proceedings of the XIX international Linac conference (open access)

Proceedings of the XIX international Linac conference

None
Date: March 31, 1999
Creator: Eyberger, C. E.; Pardo, R. C.; White, M. M. & Jaje, K. M.
Object Type: Article
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.
Object Type: Report
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.
Object Type: Report
System: The UNT Digital Library
Surface plasmon enhanced interfacial electron transfer and resonance Raman, surface-enhanced resonance Raman studies of cytochrome C mutants (open access)

Surface plasmon enhanced interfacial electron transfer and resonance Raman, surface-enhanced resonance Raman studies of cytochrome C mutants

Surface plasmon resonance was utilized to enhance the electron transfer at silver/solution interfaces. Photoelectrochemical reductions of nitrite, nitrate, and CO{sub 2} were studied on electrochemically roughened silver electrode surfaces. The dependence of the photocurrent on photon energy, applied potential and concentration of nitrite demonstrates that the photoelectrochemical reduction proceeds via photoemission process followed by the capture of hydrated electrons. The excitation of plasmon resonances in nanosized metal structures resulted in the enhancement of the photoemission process. In the case of photoelectrocatalytic reduction of CO{sub 2}, large photoelectrocatalytic effect for the reduction of CO{sub 2} was observed in the presence of surface adsorbed methylviologen, which functions as a mediator for the photoexcited electron transfer from silver metal to CO{sub 2} in solution. Photoinduced reduction of microperoxidase-11 adsorbed on roughened silver electrode was also observed and attributed to the direct photoejection of free electrons of silver metal. Surface plasmon assisted electron transfer at nanostructured silver particle surfaces was further determined by EPR method.
Date: November 8, 1999
Creator: Zheng, Junwei
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Preliminary studies on identification of inorganic species in complex mixtures by electrospray mass spectrometry in the counter ion mode (open access)

Preliminary studies on identification of inorganic species in complex mixtures by electrospray mass spectrometry in the counter ion mode

Suppression of mass spectral peaks due to matrix problem is a major hurdle to overcome during identification work. So far, preliminary studies have been done in investigating solutions containing various percentages of nitric and hydrochloric acid. Since other anions would also be present in real samples, also needed to be examined is how the extent of suppression of metal complexes by Cl{sup {minus}} compares with suppression by other anions such as PO{sub 4}{sup 3{minus}} or SO{sub 4}{sup 2{minus}}. If suppression of other anions is as severe as that of the chloride ion, then it would be virtually impossible to analyze unknown samples containing large amount of such anions by direct infusion electrospray mass spectrometry. It seems like a separation step is needed to separate these matrix anions from the metal complexes prior to putting the solution through the electrospray. However, separation of inorganic complexes can be difficult and has not been studied thoroughly as LC separation of bioorganic compounds. Both zinc and copper chloro complexes have been observed to be more tolerant to higher amount of chloride ion present in a solution compared to the group I and II metal chloro complexes. Other transition metals including the lanthanide complexes need …
Date: November 8, 1999
Creator: Mollah, Sahana
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Texas EMS Magazine, Volume 20, Number 6, November/December 1999 (open access)

Texas EMS Magazine, Volume 20, Number 6, November/December 1999

Bimonthly magazine containing news and information that pertains to Emergency Medical Service (EMS) providers. "The magazine's goals are to help organizations function professionally as EMS providers, to educate individuals so they can perform lifesaving prehospital skills under stressful conditions, and to help the public get into the EMS system when they need it" (p. 4).
Date: November 1999
Creator: Texas. Department of State Health Services.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
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.
Object Type: Report
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
Object Type: Report
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.
Object Type: Report
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
Object Type: Report
System: The UNT Digital Library
Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty (open access)

Proceedings of the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear Test-Ban Treaty

These proceedings contain papers prepared for the 21st Seismic Research Symposium: Technologies for Monitoring The Comprehensive Nuclear-Test-Ban Treaty, held 21-24 September 1999 in Las Vegas, Nevada. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Technical Applications Center (AFTAC), Department of Defense (DoD), the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 1999
Creator: Warren, N. Jill
Object Type: Article
System: The UNT Digital Library
Temporal Changes in the Spatial Variability of Soil Nutrients (open access)

Temporal Changes in the Spatial Variability of Soil Nutrients

This paper reports the temporal changes in the spatial variability of soil nutrient concentrations across a field during the growing season, over a four-year period. This study is part of the Site-Specific Technologies for Agriculture (SST4Ag) precision farming research project at the INEEL. Uniform fertilization did not produce a uniform increase in fertility. During the growing season, several of the nutrients and micronutrients showed increases in concentration although no additional fertilization had occurred. Potato plant uptake did not explain all of these changes. Some soil micronutrient concentrations increased above levels considered detrimental to potatoes, but the plants did not show the effects in reduced yield. All the nutrients measured changed between the last sampling in the fall and the first sampling the next spring prior to fertilization. The soil microbial community may play a major role in the temporal changes in the spatial variability of soil nutrient concentrations. These temporal changes suggest potential impact when determining fertilizer recommendations, and when evaluating the results of spatially varying fertilizer application.
Date: July 1, 1999
Creator: Hoskinson, Reed Louis; Hess, John Richard & Alessi, Randolph Samuel
Object Type: Article
System: The UNT Digital Library
FCC Record, Volume 14, No. 25, Pages 13198 to 13833, August 9 - August 20, 1999 (open access)

FCC Record, Volume 14, No. 25, Pages 13198 to 13833, August 9 - August 20, 1999

Biweekly, comprehensive compilation of decisions, reports, public notices, and other documents of the U.S. Federal Communications Commission.
Date: August 1999
Creator: United States. Federal Communications Commission.
Object Type: Book
System: The UNT Digital Library
DOE Laboratory Catalysis Research Symposium - Abstracts (open access)

DOE Laboratory Catalysis Research Symposium - Abstracts

The conference consisted of two sessions with the following subtopics: (1) Heterogeneous Session: Novel Catalytic Materials; Photocatalysis; Novel Processing Conditions; Metals and Sulfides; Nuclear Magnetic Resonance; Metal Oxides and Partial Oxidation; Electrocatalysis; and Automotive Catalysis. (2) Homogeneous Catalysis: H-Transfer and Alkane Functionalization; Biocatalysis; Oxidation and Photocatalysis; and Novel Medical, Methods, and Catalyzed Reactions.
Date: February 1, 1999
Creator: Dunham, T.
Object Type: Article
System: The UNT Digital Library
Injection of Gold Ions in the AGS Booster With Linear Coupling. (open access)

Injection of Gold Ions in the AGS Booster With Linear Coupling.

Linear Coupling, introduced by skew quadrupoles, has been used for several years to enhance the multi-turn injection efficiency of gold and other heavy ions in the AGS Booster. In this paper we describe our latest measurements of the injection process and compare with models.
Date: March 29, 1999
Creator: Gardne, C.; Ahrens, L.; Roser, T. & Zeno, K.
Object Type: Article
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
Object Type: Report
System: The UNT Digital Library
Non-Destructive Bulk Soil Analysis for a Chlorinated Compound using Prompt Gamma-Ray Neutron Activation Analysis (open access)

Non-Destructive Bulk Soil Analysis for a Chlorinated Compound using Prompt Gamma-Ray Neutron Activation Analysis

A prompt gamma-ray neutron activation analysis (PGNAA) system was evaluated for the quantification of chlorinated compounds in soil. The system evaluation was divided into two phases. In phase one, the response of an n-type HPGe detector (20 percent relative efficiency) to point sources of 60Co and 152Eu was determined experimentally and used to calibrate an MCNP4a model of the detector. The refined MCNP4a detector model can predict the absolute peak detection efficiency within 7 percent in the energy range of 120 - 1400 keV. In phase two, a PGNAA system consisting of a light-water moderated 252Cf (1.06 mg) neutron source, and the shielded and collimated HPGe detector was used to collect prompt gamma-ray spectra from Savannah River Site (SRS) soil spiked with chlorine. The experimental system response was used to calculate the minimum detectable concentration of chlorine in the SRS soil for a 1800 sec. irradiation as 2200 mg/g based on the analysis of the 788 keV gamma-ray. MCNP4a was used to predict the PGNAA system response, which was accomplished by analyzing the neutron and gamma ray transport components separately. In the energy range of 788 to 6110 keV, the MCNP4a predictions were generally within 60 percent of the calculated …
Date: April 19, 1999
Creator: Sigg, R.A.
Object Type: Article
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.
Object Type: Report
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
Object Type: Report
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
Object Type: Report
System: The UNT Digital Library
Texas Veterans Commission Journal, Volume 22, Issue 6, November/December 1999 (open access)

Texas Veterans Commission Journal, Volume 22, Issue 6, November/December 1999

Magazine for the state agency serving the needs of Texas veterans and their families in matters pertaining to veterans' benefits, rights, education, and employment.
Date: November 1999
Creator: Texas Veterans Commission
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
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
Object Type: Report
System: The UNT Digital Library