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Environmental Sciences

2004

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Articles 1 - 19 of 19

Full-Text Articles in Physics

The Electrochemical Separation Of Curium And Americium: Quaterly Report August-December 2004, David W. Hatchett, Kenneth Czerwinski Dec 2004

The Electrochemical Separation Of Curium And Americium: Quaterly Report August-December 2004, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This research report outlines the current status and progress associated with the electrochemical separation of Curium and Americium. The following pages outline the progress on our project to date. We have been actively performing research on this project for three months and are currently on schedule in terms of the proposed timelines.

The initial focus of the project involved setting up the laboratories for the studies outlined in the grant proposal. The instrumentation needed included an electrochemical work station that will perform the bulk of the electrochemical studies. This instrument will complement the electrochemical instrumentation in Dr. Hatchett’s laboratory ...


Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, October 2004 To December 2004, Earl Wolfram, Thomas Hartmann, Kenneth Czerwinski Dec 2004

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, October 2004 To December 2004, Earl Wolfram, Thomas Hartmann, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert matrix fuels containing ZrO2 and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO2. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of 239Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide thermodynamic ...


Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report September-December 2004, Denis Beller Dec 2004

Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report September-December 2004, Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is accelerator driven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems ...


Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus Oct 2004

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus

Fuels Campaign (TRP)

Second task of the BGU part of “Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix” project aims at evaluation of the fertile free fuel matrix composition effect on the fuel reactivity and corresponding reactivity limited burnup. Fertile free fuel with different MgO to ZrO2 ratio in the matrix will require different PuO2 loading in order to assure certain fuel cycle length. This is due to the fact that absorption cross section of Zr is slightly higher than that of Mg, although absorption in both of these elements is small compared to Pu. Therefore, the ...


Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus Sep 2004

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, A. Galperin, E. Shwageraus

Fuels Campaign (TRP)

This progress report presents results of analysis performed within the framework of “Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix” project managed by University of Nevada at Las Vegas, Harry Reid Center for Environmental Studies.

The BGU working program includes the following four tasks:

1. Benchmark of computational tools

2. Determination of fissile Pu loading

3. Evaluation of burnable poison designs

4. Evaluation of reactivity feedback coefficients

This progress report presents the results of Task 1. The main objective of this task is to confirm the validity of the ELCOS 1 code system for inert matrix ...


Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, July 2004 To September 2004, Kenneth Czerwinski, Earl Wolfram Sep 2004

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, July 2004 To September 2004, Kenneth Czerwinski, Earl Wolfram

Fuels Campaign (TRP)

This project will examine inert fuels containing ZrO2 and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO2. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10 % of 239Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide thermodynamic data ...


Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report June-August 2004, Denis Beller Aug 2004

Neutron Multiplicity Measurements For The Afci Program Quarterly Progress Report June-August 2004, Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is acceleratordriven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems, complex ...


Spectroscopic And Microscopic Investigation Of The Corrosion Of 316/316l Stainless Steel By Lead-Bismuth Eutectic (Lbe) At Elevated Temperatures: Importance Of Surface Preparation, Allen L. Johnson, Denise Parsons, Julia Manzerova, Dale L. Perry, Daniel Koury, Brian D. Hosterman, John Farley Jul 2004

Spectroscopic And Microscopic Investigation Of The Corrosion Of 316/316l Stainless Steel By Lead-Bismuth Eutectic (Lbe) At Elevated Temperatures: Importance Of Surface Preparation, Allen L. Johnson, Denise Parsons, Julia Manzerova, Dale L. Perry, Daniel Koury, Brian D. Hosterman, John Farley

Transmutation Sciences Materials (TRP)

The corrosion of steel by lead–bismuth eutectic (LBE) is an important issue in proposed nuclear transmutation schemes. Russian scientists at the IPPE exposed steel samples to oxygen-controlled LBE at temperatures up to 823 K and exposure times up to 3000 h. We have characterized these post-exposure steel samples and unexposed controls, using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). Previous researchers have investigated the corrosion by LBE of steel of varying composition. In the present work, we compared two samples having the same composition (standard nuclear grade 316/316L) but different surface preparation ...


Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski May 2004

Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

The objective of this project is to develop a method for the separation of Am from Cm based on electrochemical techniques. Electrochemical systems that allow the thermodynamics of actinide and lanthanide complexes to be systematically evaluated and tuned will be examined. The influence of complex formation on the ability to selectively isolate a given species electrochemically will be evaluated. Metal-ligand complex formation provides a useful derivation technique to increase solubility in solution environments that favor precipitation. In addition, the thermodynamic properties of a complex relative to the isolated species may be shifted to more suitably measurable electrochemical separation regimes. Electrochemical ...


Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer May 2004

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer

Fuels Campaign (TRP)

This proposal addresses the subject heading ‘Transmutation Fuel Development’ in the 2004 research topic list of the UNLV Transmutation Research Program (TRP) and DOE Advanced Fuel Cycle Initiative (AFCI). The large-scale deployment of remote fabrication and refabrication processes (with a capacity of approx. 100 metric tons of Minor Actinides (MA) annually) will be required for all transmutation scenarios. The objective of this project is the design, analysis, and evaluation of manufacturing processes for transmuter fuel fabrication. Fabrication processes for different fuel types differ in terms of equipment types, throughput, and cost. The evaluation of the fabrication processes will create a ...


Preparation Studies For Secondary Electron Emission Experiments On Superconducting Niobium, Anoop George, Robert A. Schill Jr. Mar 2004

Preparation Studies For Secondary Electron Emission Experiments On Superconducting Niobium, Anoop George, Robert A. Schill Jr.

Transmutation Sciences Materials (TRP)

Accelerator driven transmutation of waste is one complementary approach to deal with spent nuclear fuel as compared to permanent storage. High-energy protons generated by a particle accelerator collide with a heavy metal target producing neutrons. Long-lived radioactive isotopes interacting with the neutrons transmute into shorter-lived isotopes. To generate the high-energy protons efficiently, linear accelerators use multi-cell superconducting radio frequency (RF) cavities made of niobium. Superconducting niobium cavities have several advantages, including small power dissipation. The high electromagnetic fields present in these cavities may result in undesired field emission from surface imperfections with the probability of generating an avalanche of secondary ...


The Electrochemical Separation Of Curium And Americium: Quaterly Report January - March 2004, David W. Hatchett, Kenneth Czerwinski Mar 2004

The Electrochemical Separation Of Curium And Americium: Quaterly Report January - March 2004, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

This research report outlines the current status and progress associated with the electrochemical separation of Curium and Americium.

Data collection and analysis of the Ce3+/Ce4+ redox couple in various supporting electrolytes has continued. All electrolyte systems were investigated at Pt, Au, and Glassy Carbon working electrodes. Analysis of these data was accomplished by performing appropriate background subtractions to reveal net peaks due to Ce redox behavior. Successful identification of the Ce redox couple was achieved with all electrolyte/electrode systems, although a decline in peak resolution was observed with increasing acid concentration. Optimal conditions in this experiment ...


Proposal For No-Cost Extension And Re-Scope For Unlv Trp Project: Neutron Multiplicity Measurements For The Afci Program (Advanced Fuel Cycle Initiative), Denis Beller Feb 2004

Proposal For No-Cost Extension And Re-Scope For Unlv Trp Project: Neutron Multiplicity Measurements For The Afci Program (Advanced Fuel Cycle Initiative), Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is accelerator-driven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems, complex ...


Nuclear Criticality, Shielding, And Thermal Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth Jan 2004

Nuclear Criticality, Shielding, And Thermal Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth

Separations Campaign (TRP)

The first step in any transmutation strategy is the separation of radionuclides in used nuclear fuel. The current separation strategy supporting the Advanced Fuel Cycle Initiative (AFCI) program is based on the use of a solvent extraction separation process to separate the actinides, fission products, and uranium from used commercial nuclear fuel, and on the use of pyrochemical separation technologies to process used transmuter fuels. To separate the fission products and transuranic elements from the uranium in used fuel, the national program is developing a new solvent extraction process, the Uranium Extraction Plus, or UREX+, process based on the traditional ...


Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski Jan 2004

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert fuels containing ZrO2 and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO2. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10 % of 239Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide thermodynamic data ...


Neutron Multiplicity Measurements Of Target/Blanket Materials, Denis Beller Jan 2004

Neutron Multiplicity Measurements Of Target/Blanket Materials, Denis Beller

Transmutation Sciences Physics (TRP)

To optimize the performance of accelerator-driven transmutation subcritical systems (ADS), engineers will need to design the system to operate with a neutron multiplication factor just below that of a critical, or self-sustaining, system. This design criterion requires particle transport codes that instill the highest level of confidence with minimal uncertainty, because larger uncertainties in the codes require larger safety margins in the design and result in a lower efficiency of the ADS transmuter. For current design efforts in the U.S., a Monte Carlo particle transport code MCNPX is used to model neutron production and transport for spallation neutron systems ...


Radiation Transport Modeling Using Parallel Computational Techniques, William Culbreth, Denis Beller Jan 2004

Radiation Transport Modeling Using Parallel Computational Techniques, William Culbreth, Denis Beller

Reactor Campaign (TRP)

The second year of this project involved modeling several aspects of the LANCSE beam experiments:

  • Modeling targets of varying diameter in air, in a vacuum, and in the presence of humid air;
  • Modeling various proton beam profiles;
  • Modeling the effects of off-axis proton beam impingement on the target;
  • Modeling the asymmetry introduced by the steel table below the target;
  • Modeling the effect of varying ratios of Pb to Bi and the effect of impurities; and
  • Modeling the system, including other structures within the test room.

With the experience gained through modeling these systems, the UNLV researchers plan, with the assistance ...


Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Allen L. Johnson, Dale L. Perry Jan 2004

Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

There is an active international interest in lead-bismuth eutectic and similar liquid lead systems because of the relevance to the transmutation of nuclear waste, fast reactors, and spallation neutron sources. A successful program in nuclear waste processing that includes transmutation in accelerator-driven systems and fast reactors, would significantly decrease the space requirements for geological repositories.

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For lead bismuth eutectic (LBE) systems, there is an additional challenge because the corrosive behaviors of materials in LBE are not well understood. Most of the available information ...


Stress Corrosion Cracking Of Target Material, Mohammad K. Hossain Jan 2004

Stress Corrosion Cracking Of Target Material, Mohammad K. Hossain

Transmutation Sciences Materials (TRP)

The primary objective of this paper is to evaluate the effect of hydrogen on environment assisted cracking of candidate target materials for transmutation applications. Transmutation refers to transformation of long-lived actinides and fission products from spent nuclear fuels (SNF), and occurs when the nucleus of an atom changes because of natural radioactive decay, nuclear fission, nuclear fusion, neutron capture, or other related processes. Martensitic Alloy EP 823 was selected to be the candidate alloy for this investigation. During the initial phase, the stress corrosion cracking (SCC) behavior of this alloy was evaluated in neutral (pH: 6-7) and acidic (pH: 2-3 ...