Base sequence effects on interactions of aromatic mutagens with DNA (open access)

Base sequence effects on interactions of aromatic mutagens with DNA

The chemical binding of bulky, mutagenic and carcinogenic polynuclear aromatic compounds to certain base-sequences in genomic DNA is known to inhibit DNA replication, and to induce mutations and cancer. In particular, sequences that contain multiple consecutive guanines appear to be hot spots of mutation. The objectives of this research are to determine how the base sequence around the mutagen-modified target bases influences the local DNA conformation and gives rise to mispairing of bases, or deletions, near the lesion. Oligonucleotides containing one, two, or three guanines were synthesized and chemically reacted with the mutagen anti-7,8-dihydroxy-9,10-epoxy-benzo(a)pyrene (BPDE), one of the most mutagenic and tumorigenic metabolites of benzo(a)pyrene. Adducts are formed in which only one of the guanines is modified by trans or cis addition to the exocyclic amino group. The BPDE-oligonucleotides are separated chromatographically, and the site of modification is established by Maxam-Gilbert high resolution gel electrophoresis techniques. The thermodynamic properties of duplexes using complementary, or partially complementary strands were examined. In the latter, the base opposite the modified guanine was varied in order to investigate the probability of mispairing of the modified G with A,T and G. The successful synthesis of stereospecific and site-specific mutagen-oligonucleotide adducts opens new possibilities for correlating …
Date: September 30, 1992
Creator: Geacintov, N. E.
Object Type: Report
System: The UNT Digital Library
Base sequence effects on interactions of aromatic mutagens with DNA. Progress report, September 1, 1991--August 31, 1992 (open access)

Base sequence effects on interactions of aromatic mutagens with DNA. Progress report, September 1, 1991--August 31, 1992

The chemical binding of bulky, mutagenic and carcinogenic polynuclear aromatic compounds to certain base-sequences in genomic DNA is known to inhibit DNA replication, and to induce mutations and cancer. In particular, sequences that contain multiple consecutive guanines appear to be hot spots of mutation. The objectives of this research are to determine how the base sequence around the mutagen-modified target bases influences the local DNA conformation and gives rise to mispairing of bases, or deletions, near the lesion. Oligonucleotides containing one, two, or three guanines were synthesized and chemically reacted with the mutagen anti-7,8-dihydroxy-9,10-epoxy-benzo[a]pyrene (BPDE), one of the most mutagenic and tumorigenic metabolites of benzo[a]pyrene. Adducts are formed in which only one of the guanines is modified by trans or cis addition to the exocyclic amino group. The BPDE-oligonucleotides are separated chromatographically, and the site of modification is established by Maxam-Gilbert high resolution gel electrophoresis techniques. The thermodynamic properties of duplexes using complementary, or partially complementary strands were examined. In the latter, the base opposite the modified guanine was varied in order to investigate the probability of mispairing of the modified G with A,T and G. The successful synthesis of stereospecific and site-specific mutagen-oligonucleotide adducts opens new possibilities for correlating …
Date: September 30, 1992
Creator: Geacintov, N. E.
Object Type: Report
System: The UNT Digital Library
Brittle to ductile transition in cleavage fracture (open access)

Brittle to ductile transition in cleavage fracture

The problem of interpretation of fracture transition from brittle to ductile or vice versa is the subject of study. An instrumented tapered double cantilever beam (TDCB) has been developed as a definitive tool in the study of the intrinsic mechanism in single crystalline samples. In this experiment, the crack velocity is directly proportional to actuator velocity. In experiments performed on TDCB shaped Si single crystals, oriented for cleavage on either [l brace]111[r brace] or [l brace]110[r brace] planes, a number of troubling features of jerky carck extension were encountered. Evidence suggests that nucleation of dislocation loops from crack tip is easier than moving these dislocations away from crack tip. 14 refs, 1 fig.
Date: September 30, 1992
Creator: Argon, A. S. & Berg, Q.
Object Type: Report
System: The UNT Digital Library
Brittle to ductile transition in cleavage fracture. Final techical report, April 1, 1987--June 30, 1991 (open access)

Brittle to ductile transition in cleavage fracture. Final techical report, April 1, 1987--June 30, 1991

The problem of interpretation of fracture transition from brittle to ductile or vice versa is the subject of study. An instrumented tapered double cantilever beam (TDCB) has been developed as a definitive tool in the study of the intrinsic mechanism in single crystalline samples. In this experiment, the crack velocity is directly proportional to actuator velocity. In experiments performed on TDCB shaped Si single crystals, oriented for cleavage on either {l_brace}111{r_brace} or {l_brace}110{r_brace} planes, a number of troubling features of jerky carck extension were encountered. Evidence suggests that nucleation of dislocation loops from crack tip is easier than moving these dislocations away from crack tip. 14 refs, 1 fig.
Date: September 30, 1992
Creator: Argon, A. S. & Berg, Q.
Object Type: Report
System: The UNT Digital Library
Catalytic conversion of light alkanes. [Methane, ethane, propane and butanes] (open access)

Catalytic conversion of light alkanes. [Methane, ethane, propane and butanes]

The third and last quarterly report of 1992 on the Catalytic conversion of Light Alkanes reviews the work done between July, 1992 and September 30, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products which can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon transportation fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II) and framework-substituted zeolites (PHASE III).
Date: September 30, 1992
Creator: Lyons, J. E.
Object Type: Report
System: The UNT Digital Library
Catalytic conversion of light alkanes. Quarterly progress report, July 1, 1992--September 30, 1992 (open access)

Catalytic conversion of light alkanes. Quarterly progress report, July 1, 1992--September 30, 1992

The third and last quarterly report of 1992 on the Catalytic conversion of Light Alkanes reviews the work done between July, 1992 and September 30, 1992 on the Cooperative Agreement. The mission of this work is to devise a new catalyst which can be used in a simple economic process to convert the light alkanes in natural gas to oxygenate products which can either be used as clean-burning, high octane liquid fuels, as fuel components or as precursors to liquid hydrocarbon transportation fuel. During the past quarter we have continued to design, prepare, characterize and test novel catalysts for the mild selective reaction of light hydrocarbons with air or oxygen to produce alcohols directly. These catalysts are designed to form active metal oxo (MO) species and to be uniquely active for the homolytic cleavage of the carbon-hydrogen bonds in light alkanes producing intermediates which can form alcohols. We continue to investigate three molecular environments for the active catalytic species that we are trying to generate: electron-deficient macrocycles (PHASE I), polyoxometallates (PHASE II) and framework-substituted zeolites (PHASE III).
Date: September 30, 1992
Creator: Lyons, J. E.
Object Type: Report
System: The UNT Digital Library
Characterization of the Defense Waste Processing Facility (DWPF) Environmental Assessment (EA) glass standard reference material (open access)

Characterization of the Defense Waste Processing Facility (DWPF) Environmental Assessment (EA) glass standard reference material

Liquid high-level nuclear waste at the Savannah River Site (SRS) will be immobilized by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Other waste form producers, such as West Valley Nuclear Services (WVNS) and the Hanford Waste Vitrification Project (HWVP), will also immobilize high-level radioactive waste in borosilicate glass. The canistered waste will be stored temporarily at each facility for eventual permanent disposal in a geologic repository. The Department of Energy has defined a set of requirements for the canistered waste forms, the Waste Acceptance Preliminary Specifications (WAPS). The current Waste Acceptance Preliminary Specification (WAPS) 1.3, the product consistency specification, requires the waste form producers to demonstrate control of the consistency of the final waste form using a crushed glass durability test, the Product Consistency Test (PCT). In order to be acceptable, a waste glass must be more durable during PCT analysis than the waste glass identified in the DWPF Envirorunental Assessment (EA). In order to supply all the waste form producers with the same standard benchmark glass, 1000 pounds of the EA glass was fabricated. The chemical analyses and characterization of the benchmark EA glass …
Date: September 30, 1992
Creator: Jantzen, Carol M.; Bibler, N. E. & Beam, D. C.
Object Type: Report
System: The UNT Digital Library
Characterization of the Defense Waste Processing Facility (DWPF) Environmental Assessment (EA) glass standard reference material. [Site Characterization] (open access)

Characterization of the Defense Waste Processing Facility (DWPF) Environmental Assessment (EA) glass standard reference material. [Site Characterization]

Liquid high-level nuclear waste at the Savannah River Site (SRS) will be immobilized by vitrification in borosilicate glass. The glass will be produced and poured into stainless steel canisters in the Defense Waste Processing Facility (DWPF). Other waste form producers, such as West Valley Nuclear Services (WVNS) and the Hanford Waste Vitrification Project (HWVP), will also immobilize high-level radioactive waste in borosilicate glass. The canistered waste will be stored temporarily at each facility for eventual permanent disposal in a geologic repository. The Department of Energy has defined a set of requirements for the canistered waste forms, the Waste Acceptance Preliminary Specifications (WAPS). The current Waste Acceptance Preliminary Specification (WAPS) 1.3, the product consistency specification, requires the waste form producers to demonstrate control of the consistency of the final waste form using a crushed glass durability test, the Product Consistency Test (PCT). In order to be acceptable, a waste glass must be more durable during PCT analysis than the waste glass identified in the DWPF Envirorunental Assessment (EA). In order to supply all the waste form producers with the same standard benchmark glass, 1000 pounds of the EA glass was fabricated. The chemical analyses and characterization of the benchmark EA glass …
Date: September 30, 1992
Creator: Jantzen, Carol M.; Bibler, N. E. & Beam, D. C.
Object Type: Report
System: The UNT Digital Library
The comparison of DYNA3D to approximate solutions for a partially- full waste storage tank subjected to seismic loading (open access)

The comparison of DYNA3D to approximate solutions for a partially- full waste storage tank subjected to seismic loading

Mathematical solutions to the problem consisting of a partially-full waste tank subjected to seismic loading, embedded in soil, is classically difficult in that one has to address: soil-structure interaction, fluid-structure interaction, non-linear behavior of material, dynamic effects. Separating the problem and applying numerous assumptions will yield approximate solutions. This paper explores methods for generating these solutions accurately.
Date: September 30, 1992
Creator: Zaslawsky, M. & Kennedy, W. N.
Object Type: Report
System: The UNT Digital Library
The comparison of DYNA3D to approximate solutions for a partially- full waste storage tank subjected to seismic loading (open access)

The comparison of DYNA3D to approximate solutions for a partially- full waste storage tank subjected to seismic loading

Mathematical solutions to the problem consisting of a partially-full waste tank subjected to seismic loading, embedded in soil, is classically difficult in that one has to address: soil-structure interaction, fluid-structure interaction, non-linear behavior of material, dynamic effects. Separating the problem and applying numerous assumptions will yield approximate solutions. This paper explores methods for generating these solutions accurately.
Date: September 30, 1992
Creator: Zaslawsky, M. & Kennedy, W. N.
Object Type: Report
System: The UNT Digital Library
Detection of nitroesters and moisture in combustible cartridge case wall by indicator strips and instruments. Final report (open access)

Detection of nitroesters and moisture in combustible cartridge case wall by indicator strips and instruments. Final report

Nitroester migration into the case wall from the propellant and moisture accumulation within the case have been identified as important internal and external (respectively) factors which contribute to the physical deterioration of combustible cartridge case (ccc) munitions. The latter factor also may hinder proper ignition of the ccc and cause incomplete combustion in firing. Visual indicators sensitive to these factors and affixed to ccc rounds would allow quality assurance specialists or gun crews in the field to rapidly determine the potential reliability of individual rounds. Previous work in this task identified chemistries suitable for the detection of nitroesters and moisture in the ccc wall. A version of the Griess reaction was modified for a dry colorimetric indicator which in the presence of nitroglycerin (NG) or diethyleneglycol dinitrate (DEGDN) generates a brilliant red color. Inorganic salts such as cupric chloride, which changes from brown to blue-green upon hydration, were suggested as promising visual indicators of moisture. This report describes the development and preliminary testing of prototype nitroester and moisture indicator strips, and the scoping of two instrumental techniques, infrared spectroscopy and electrical capacitance, which could lead to portable instruments for rapid and nondestructive testing of ccc in the field.
Date: September 30, 1992
Creator: Ho, C. H.; Moneyhun, J. H.; Agouridis, D. C.; Gayle, T. M.; Hurst, G. B. & Griest, W. H.
Object Type: Report
System: The UNT Digital Library
Developing integrated benchmarks for DOE performance measurement (open access)

Developing integrated benchmarks for DOE performance measurement

The objectives of this task were to describe and evaluate selected existing sources of information on occupational safety and health with emphasis on hazard and exposure assessment, abatement, training, reporting, and control identifying for exposure and outcome in preparation for developing DOE performance benchmarks. Existing resources and methodologies were assessed for their potential use as practical performance benchmarks. Strengths and limitations of current data resources were identified. Guidelines were outlined for developing new or improved performance factors, which then could become the basis for selecting performance benchmarks. Data bases for non-DOE comparison populations were identified so that DOE performance could be assessed relative to non-DOE occupational and industrial groups. Systems approaches were described which can be used to link hazards and exposure, event occurrence, and adverse outcome factors, as needed to generate valid, reliable, and predictive performance benchmarks. Data bases were identified which contain information relevant to one or more performance assessment categories . A list of 72 potential performance benchmarks was prepared to illustrate the kinds of information that can be produced through a benchmark development program. Current information resources which may be used to develop potential performance benchmarks are limited. There is need to develop an occupational safety …
Date: September 30, 1992
Creator: Barancik, J. I.; Kramer, C. F. & Thode Jr., H. C.
Object Type: Report
System: The UNT Digital Library
Developing integrated benchmarks for DOE performance measurement (open access)

Developing integrated benchmarks for DOE performance measurement

The objectives of this task were to describe and evaluate selected existing sources of information on occupational safety and health with emphasis on hazard and exposure assessment, abatement, training, reporting, and control identifying for exposure and outcome in preparation for developing DOE performance benchmarks. Existing resources and methodologies were assessed for their potential use as practical performance benchmarks. Strengths and limitations of current data resources were identified. Guidelines were outlined for developing new or improved performance factors, which then could become the basis for selecting performance benchmarks. Data bases for non-DOE comparison populations were identified so that DOE performance could be assessed relative to non-DOE occupational and industrial groups. Systems approaches were described which can be used to link hazards and exposure, event occurrence, and adverse outcome factors, as needed to generate valid, reliable, and predictive performance benchmarks. Data bases were identified which contain information relevant to one or more performance assessment categories . A list of 72 potential performance benchmarks was prepared to illustrate the kinds of information that can be produced through a benchmark development program. Current information resources which may be used to develop potential performance benchmarks are limited. There is need to develop an occupational safety …
Date: September 30, 1992
Creator: Barancik, J. I.; Kramer, C. F. & Thode, Jr. H. C.
Object Type: Report
System: The UNT Digital Library
Electrokinetic migration studies on removal of chromium and uranyl ions from 904-A trench soil (open access)

Electrokinetic migration studies on removal of chromium and uranyl ions from 904-A trench soil

This report describes a laboratory-scale study, in which electrokinetic migration technology was used to remove chromium and uranium, as well as other ions, from soil taken from a bore hole adjacent to the 904-A trench at the Savannah River Technology Center. Imposition of an electric current on humid (not saturated) soil successfully caused cations to migrate through the pore water of the soil to the cathode, where they were captured in an ISOLOCKTm polymer matrix and in a cation exchange resin incorporated in the polymer. Chemicals circulated through the anode/polymer and cathode/polymer were able to control pH excursions in the electrokinetic-cells by reacting with the H[sup +] and OH[sup [minus]] generated at the anode and cathode, respectively. The study indicates that ions adsorbed on the surface of the soil as well as those in the pores of soil particles can be caused to migrate through the soil to an appropriate electrode. After 10 days of operation at 20--25 V and 2 mA, approximately 65% of the chromium was removed from two 3.5 kg soil samples. A 57% removal of uranium was achieved. The study shows that electrokinetic migration, using the ISOLOCK[trademark] polymer will be effective as an in situ treatment …
Date: September 30, 1992
Creator: Bibler, J. P.; Meaker, T. F. & O'Steen, A. B.
Object Type: Report
System: The UNT Digital Library
Electrokinetic Migration Studies on Removal of Chromium and Uranyl Ions From 904-a Trench Soil (open access)

Electrokinetic Migration Studies on Removal of Chromium and Uranyl Ions From 904-a Trench Soil

This report describes a laboratory-scale study, in which electrokinetic migration technology was used to remove chromium and uranium, as well as other ions, from soil taken from a bore hole adjacent to the 904-A trench at the Savannah River Technology Center. Imposition of an electric current on humid (not saturated) soil successfully caused cations to migrate through the pore water of the soil to the cathode, where they were captured in an ISOLOCKTm polymer matrix and in a cation exchange resin incorporated in the polymer. Chemicals circulated through the anode/polymer and cathode/polymer were able to control pH excursions in the electrokinetic-cells by reacting with the H{sup +} and OH{sup {minus}} generated at the anode and cathode, respectively. The study indicates that ions adsorbed on the surface of the soil as well as those in the pores of soil particles can be caused to migrate through the soil to an appropriate electrode. After 10 days of operation at 20--25 V and 2 mA, approximately 65% of the chromium was removed from two 3.5 kg soil samples. A 57% removal of uranium was achieved. The study shows that electrokinetic migration, using the ISOLOCK{trademark} polymer will be effective as an in situ treatment …
Date: September 30, 1992
Creator: Bibler, J. P.; Meaker, T. F. & O'Steen, A. B.
Object Type: Report
System: The UNT Digital Library
Hydrodynamic controls on particle transport through heterogeneous porous media (open access)

Hydrodynamic controls on particle transport through heterogeneous porous media

The initial stages of this project have been focused on equipment development and preliminary experimental efforts. Among the accomplishments to date are the development of a successful flow cell design, proof of the utility of the UV resin, adjustment of the Laser Particle Counter to produce reliable readings, installation of a low particle content water supply, installation of a microscope for viewing discharge samples, development of a fiber/rod optic system for freezing the UV resin in situ and performance of initial experiments on layered and complex heterogeneities. The work is currently following very closely the original schedule for research efforts. Continuing efforts in year one will include continued efforts in simple and complex heterogeneity in two-dimensions, extension into three-dimensions, consideration of the most appropriate methods for creating geologically realistic structures in the laboratory, interaction with other SSP research programs and organization of the spring meeting on intermediate-scale experimentation to be held at Notre Dame. Efforts in year two will be focused on three-dimensional experiments in saturated media, extension of results into unsaturated media, development of techniques for unsaturated media characterization, and development of research ties with outside research interests.
Date: September 30, 1992
Creator: Silliman, Stephen E.
Object Type: Report
System: The UNT Digital Library
Hydrodynamic controls on particle transport through heterogeneous porous media. Technical progress report (open access)

Hydrodynamic controls on particle transport through heterogeneous porous media. Technical progress report

The initial stages of this project have been focused on equipment development and preliminary experimental efforts. Among the accomplishments to date are the development of a successful flow cell design, proof of the utility of the UV resin, adjustment of the Laser Particle Counter to produce reliable readings, installation of a low particle content water supply, installation of a microscope for viewing discharge samples, development of a fiber/rod optic system for freezing the UV resin in situ and performance of initial experiments on layered and complex heterogeneities. The work is currently following very closely the original schedule for research efforts. Continuing efforts in year one will include continued efforts in simple and complex heterogeneity in two-dimensions, extension into three-dimensions, consideration of the most appropriate methods for creating geologically realistic structures in the laboratory, interaction with other SSP research programs and organization of the spring meeting on intermediate-scale experimentation to be held at Notre Dame. Efforts in year two will be focused on three-dimensional experiments in saturated media, extension of results into unsaturated media, development of techniques for unsaturated media characterization, and development of research ties with outside research interests.
Date: September 30, 1992
Creator: Silliman, S. E.
Object Type: Report
System: The UNT Digital Library
Intelligent distributed control for nuclear power plants. Third annual technical progress report, September 1991--October 1992 (open access)

Intelligent distributed control for nuclear power plants. Third annual technical progress report, September 1991--October 1992

This project was initiated in September 1989 as a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this Third Annual Technical Progress report summarizes the period from September 1991 to October 1992. There were two primary goals of this research project. The first goal was to combine diagnostics and control to achieve a highly automated power plant as described by M.A. Schultz. His philosophy, is to improve public perception of the safety of nuclear power plants by incorporating a high degree of automation where a greatly simplified operator control console minimizes the possibility of human error in power plant operations. To achieve this goal, a hierarchically distributed control system with automated responses to plant upset conditions was pursued in this research. The second goal was to apply this research to develop a prototype demonstration on an actual power plant system, the EBR-2 stem plant. Emphasized in this Third Annual Technical Progress Report is the continuing development of the in-plant intelligent control demonstration for the final project milestone and includes: simulation validation and the initial approach to experiment formulation.
Date: September 30, 1992
Creator: Klevans, E. H.
Object Type: Report
System: The UNT Digital Library
Investigation of high strains at the bottom of the Los Alamos confinement vessel (open access)

Investigation of high strains at the bottom of the Los Alamos confinement vessel

In helping Los Alamos to understand the vessel response of explosive confinement vessels, APTEK has provided analysis of a 6 foot diameter vessel subjected to a spherical explosive blast. Correlations between analysis and test were very good except at the bottom of the vessel. A beating response was seen in the tests which reinforced the primary response mode at the bottom of the vessel, possibly to the extent of causing local yielding at the bottom. The authors did not predict the beating response and could not explain its origin. Since both APTEK and LANL felt that understanding these strains was important, they investigated the nature and possible origins of the response. They began a systematic study of the effects of various parameters of the problem. In separate analyses, they added boundary conditions, increased the mass of the ports by 10%, and included a row of 10% stiffer material to represent the weld. Of these, only the added boundary condition had a significant effect, and the boundary condition applied (vertical fixity at the bottom of two opposite ports to simulate the slings used) caused the strains at the bottom to decrease. They also made a less refined quarter-symmetric model with three …
Date: September 30, 1992
Creator: Lewis, B. B.
Object Type: Report
System: The UNT Digital Library
Nuclear Structure from Radioactive Decay. Annual Progress Report (open access)

Nuclear Structure from Radioactive Decay. Annual Progress Report

The most important aspect of the wind-up of UNISOR-based research is completion of student theses. Analysis is proceeding on extensive studies in the neutron-deficient rare earth isotopes with N < 82 and the neutron-deficient region below Z = 82. These studies address the onset of deformation in the N < 82, Z > 50 open shell region and shape coexistence in the N {approximately} 104, Z {le} 82 region, respectively. The main ongoing topics are shape coexistence in nuclei and the microscopic structure of collective motion in nuclei from a phenomenological point of view. New topics this year focus on the structure of nuclei near the N = Z line. Two topics have been chosen for detailed study: shape coexistence and electric monopole transition strengths.
Date: September 30, 1992
Creator: Wood, J. L.
Object Type: Report
System: The UNT Digital Library
Nuclear Structure from Radioactive Decay. [School of Physics, Georgia Inst. of Tech] (open access)

Nuclear Structure from Radioactive Decay. [School of Physics, Georgia Inst. of Tech]

The most important aspect of the wind-up of UNISOR-based research is completion of student theses. Analysis is proceeding on extensive studies in the neutron-deficient rare earth isotopes with N < 82 and the neutron-deficient region below Z = 82. These studies address the onset of deformation in the N < 82, Z > 50 open shell region and shape coexistence in the N [approximately] 104, Z [le] 82 region, respectively. The main ongoing topics are shape coexistence in nuclei and the microscopic structure of collective motion in nuclei from a phenomenological point of view. New topics this year focus on the structure of nuclei near the N = Z line. Two topics have been chosen for detailed study: shape coexistence and electric monopole transition strengths.
Date: September 30, 1992
Creator: Wood, J.L.
Object Type: Report
System: The UNT Digital Library
Plutonium oxide dissolution (open access)

Plutonium oxide dissolution

Several processing options for dissolving plutonium oxide (PuO[sub 2]) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO[sub 2] typically generated by burning plutonium metal and PuO[sub 2] produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO[sub 2] in canyon dissolvers. The options involve solid solution formation of PuO[sub 2] With uranium oxide (UO[sub 2]) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO[sub 2] with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO[sub 2] materials may warrant further study.
Date: September 30, 1992
Creator: Gray, J. H.
Object Type: Report
System: The UNT Digital Library
Plutonium oxide dissolution (open access)

Plutonium oxide dissolution

Several processing options for dissolving plutonium oxide (PuO{sub 2}) from high-fired materials have been studied. The scoping studies performed on these options were focused on PuO{sub 2} typically generated by burning plutonium metal and PuO{sub 2} produced during incineration of alpha contaminated waste. At least two processing options remain applicable for dissolving high-fired PuO{sub 2} in canyon dissolvers. The options involve solid solution formation of PuO{sub 2} With uranium oxide (UO{sub 2}) and alloying incinerator ash with aluminum. An oxidative dissolution process involving nitric acid solutions containing a strong oxidizing agent, such as cerium (IV), was neither proven nor rejected. This uncertainty was due to difficulty in regenerating cerium (IV) ions during dissolution. However, recent work on silver-catalyzed dissolution of PuO{sub 2} with persulfate has demonstrated that persulfate ions regenerate silver (II). Use of persulfate to regenerate cerium (IV) or bismuth (V) ions during dissolution of PuO{sub 2} materials may warrant further study.
Date: September 30, 1992
Creator: Gray, J. H.
Object Type: Report
System: The UNT Digital Library
Risk assessment for the Yucca Mountain high-level nuclear waste repository site: Estimation of volcanic disruption. Final report (open access)

Risk assessment for the Yucca Mountain high-level nuclear waste repository site: Estimation of volcanic disruption. Final report

In this article, we model the volcanism near the proposed nuclear waste repository at Yucca Mountain, Nevada, U.S.A. by estimating the instantaneous recurrence rate using a nonhomogeneous Poisson process with Weibull intensity and by using a homogeneous Poisson process to predict future eruptions. We then quantify the probability that any single eruption is disruptive in terms of a (prior) probability distribution, since not every eruption would result in disruption of the repository. Bayesian analysis is performed to evaluate the volcanic risk. Based on the Quaternary data, a 90% confidence interval for the instantaneous recurrence rate near the Yucca Mountain site is (1.85 x 10{sup -6}/yr, 1.26 x 10{sup -5}/yr). Also, using these confidence bounds, the corresponding 90% confidence interval for the risk (probability of at least one disruptive eruption) for an isolation time of 10{sup 4} years is (1.0 x 10{sup -3}, 6.7 x 10{sup -3}), if it is assumed that the intensity remains constant during the projected time frame.
Date: September 30, 1992
Creator: Ho, Chih-Hsiang
Object Type: Report
System: The UNT Digital Library