Modeling of Fission Gas Release in UO2 (open access)

Modeling of Fission Gas Release in UO2

A two-stage gas release model was examined to determine if it could provide a physically realistic and accurate model for fission gas release under Prometheus conditions. The single-stage Booth model [1], which is often used to calculate fission gas release, is considered to be oversimplified and not representative of the mechanisms that occur during fission gas release. Two-stage gas release models require saturation at the grain boundaries before gas is release, leading to a time delay in release of gases generated in the fuel. Two versions of a two-stage model developed by Forsberg and Massih [2] were implemented using Mathcad [3]. The original Forsbers and Massih model [2] and a modified version of the Forsberg and Massih model that is used in a commercially available fuel performance code (FRAPCON-3) [4] were examined. After an examination of these models, it is apparent that without further development and validation neither of these models should be used to calculate fission gas release under Prometheus-type conditions. There is too much uncertainty in the input parameters used in the models. In addition. the data used to tune the modified Forsberg and Massih model (FRAPCON-3) was collected under commercial reactor conditions, which will have higher fission …
Date: January 23, 2006
Creator: Krohn, MH
System: The UNT Digital Library
FY2004 Progress Summary and FY2005 Program Plan Statement of Work and Deliverables (open access)

FY2004 Progress Summary and FY2005 Program Plan Statement of Work and Deliverables

FY2004 progress summary and FY2005 program plan statement of work and deliverables for development of high average power diode-pumped solid state lasers, and complementary technologies for applications in energy and defense.
Date: January 23, 2006
Creator: Meier, W. & Bibeau, C.
System: The UNT Digital Library
Field-Portable Immunoassay Instruments and Reagents to Measure Chelators and Mobile Forms of Uranium (open access)

Field-Portable Immunoassay Instruments and Reagents to Measure Chelators and Mobile Forms of Uranium

Progress Report Date: 01/23/06 (report delayed due to Hurricane Katrina) Report of results to date: The goals of this 3-year project are to: (1) update and successfully deploy our present immunosensors at DOE sites; (2) devise immunosensor-based assays for Pb(II), Hg(II), chelators, and/or Cr(III) in surface and groundwater; and (3) develop new technologies in antibody engineering that will enhance this immunosensor program. Note: Work on this project was temporarily disrupted when Hurricane Katrina shut down the University on August 29, 2005. While most of the reagents stored in our refrigerators and freezers were destroyed, all of our hybridoma cell lines were saved because they had been stored in liquid nitrogen. We set up new tissue culture reactors with the hybridomas that synthesize the anti-uranium antibodies, and are purifying new monoclonal antibodies from these culture supernatants. Both the in-line and the field-portable sensor were rescued from our labs in New Orleans in early October, and we continued experiments with these sensors in the temporary laboratory we set up in Hammond, LA at Southeastern Louisiana University.
Date: January 23, 2006
Creator: Blake, Diane A.
System: The UNT Digital Library
Development and Application of an Analysis Methodology for Interpreting Ambiguous Historical Pressure Data in the Wipp Gas-Generation Experiments. (open access)

Development and Application of an Analysis Methodology for Interpreting Ambiguous Historical Pressure Data in the Wipp Gas-Generation Experiments.

The potential for generation of gases in transuranic (TRU) waste by microbial activity, chemical interactions, corrosion, and radiolysis was addressed in the Argonne National Laboratory-West (ANL-West) Gas-Generation Experiments (GGE). Data was collected over several years by simulating the conditions in the Waste Isolation Pilot Plant (WIPP) after the eventual intrusion of brine into the repository. Fourteen test containers with various actual TRU waste immersed in representative brine were inoculated with WIPP-relevant microbes, pressurized with inert gases, and kept in an inert-atmosphere environment for several years to provide estimates of the gas-generation rates that will be used in computer models for future WIPP Performance Assessments. Modest temperature variations occurred during the long-term ANL-West experiments. Although the experiment temperatures always remained well within the experiment specifications, the small temperature variation was observed to affect the test container pressure far more than had been anticipated. In fact, the pressure variations were so large, and seemingly erratic, that it was impossible to discern whether the data was even valid and whether the long-term pressure trend was increasing, decreasing, or constant. The result was that no useful estimates of gas-generation rates could be deduced from the pressure data. Several initial attempts were made to quantify …
Date: January 23, 2006
Creator: Felicione, F. S.
System: The UNT Digital Library
Fuel-cladding interaction layers in irradiated U-ZR and U-PU-ZR fuel elements. (open access)

Fuel-cladding interaction layers in irradiated U-ZR and U-PU-ZR fuel elements.

Argonne National Laboratory is developing an electrometallurgical treatment for spent nuclear fuels. The initial demonstration of this process is being conducted on U-Zr and U-Pu-Zr alloy fuel elements irradiated in the Experimental Breeder Reactor-II (EBR-II). The electrometallurgical treatment process extracts usable uranium from irradiated fuel elements and places residual fission products, actinides, process Zr, and cladding hulls (small segments of tubing) into two waste forms--a ceramic and a metal alloy. The metal waste form will contain the cladding hulls, Zr, and noble metal fission products, and it will be disposed of in a geologic repository. As a result, the expected composition of the waste form will need to be well understood. This report deals with the condition of the cladding, which will make up a large fraction of the metal waste form, after irradiation in EBR-II and before insertion into the electrorefiner. Specifically, it looks at layers that can be found on the inner surface of the cladding due to in-reactor interactions between the alloy fuel and the stainless steel cladding that occurs after the fuel has swelled and contacted the cladding. Many detailed examinations of fuel elements irradiated in EBR-II have been completed and are discussed in the context …
Date: January 23, 2006
Creator: Keiser, D. D.
System: The UNT Digital Library
Mechanisms underlying the adaptive response against spontaneous neoplastic transformation induced by low doses of low LET radiation, Final Technical Report (open access)

Mechanisms underlying the adaptive response against spontaneous neoplastic transformation induced by low doses of low LET radiation, Final Technical Report

The goal of this project was to investigate mechanisms underlying the adaptive response seen following exposure of HeLa x skin fibroblast human hybrid cells to low doses of low LET radiation. It was proposed to investigate the contributions of three possible mechanisms. These were: 1. Upregulation of cellular antioxidant status. 2. Upregulation of DNA repair. 3. Upregulation of gap junction intracellular communication. We have completed the study of the role of upregulation of reduced glutathione (GSH) as a possible mechanism underlying our observed suppression of transformation frequency at low radiation doses. We have also completed our study of the possible role of upregulation of DNA repair in the observed adaptive response against neoplastic transformation. We concluded that upregulation of DNA repair may be more important in modulating transformation at the higher dose. A manuscript describing the above studies has been submitted published in Carcinogenesis 24:1961-1965, 2003. Finally, we have completed two studies of the possible role of upregulation of gap junction intercellular communication (GJIC) in modulating transformation frequency at low doses of low LET radiation. This research was published in Radiation Research 162:646-654, 2004. In order to optimize the opportunity for GJIC, we then carried out a study where confluent …
Date: January 23, 2006
Creator: J. Leslie Redpath, Ph.D.
System: The UNT Digital Library
Identification and Characterization of Thermobifida Fusca Genes Involved in Plant Cell Wall Degradation. (open access)

Identification and Characterization of Thermobifida Fusca Genes Involved in Plant Cell Wall Degradation.

Micro-array experiments identified a number of Thermobifida fusca genes which were upregulated by growth on cellulose or plant biomass. Five of these genes were cloned, overexpressed in E. coli and the expressed proteins were purified and characterized. These were a xyloglucanase,a 1-3,beta glucanase, a family 18 hydrolase and twocellulose binding proteins that contained no catalytic domains. The catalyic domain of the family 74 endoxyloglucanase with a C-terminal, cellulose binding module was crystalized and its 3-dimensional structure was determined by X-ray crystallography.
Date: January 23, 2006
Creator: Wilson, David B.
System: The UNT Digital Library
High Resolution Sensor for Nuclear Waste Characterization (open access)

High Resolution Sensor for Nuclear Waste Characterization

Gamma ray spectrometers are an important tool in the characterization of radioactive waste. Important requirements for gamma ray spectrometers used in this application include good energy resolution, high detection efficiency, compact size, light weight, portability, and low power requirements. None of the available spectrometers satisfy all of these requirements. The goal of the Phase I research was to investigate lanthanum halide and related scintillators for nuclear waste clean-up. LaBr3:Ce remains a very promising scintillator with high light yield and fast response. CeBr3 is attractive because it is very similar to LaBr3:Ce in terms of scintillation properties and also has the advantage of much lower self-radioactivity, which may be important in some applications. CeBr3 also shows slightly higher light yield at higher temperatures than LaBr3 and may be easier to produce with high uniformity in large volume since it does not require any dopants. Among the mixed lanthanum halides, the light yield of LaBrxI3-x:Ce is lower and the difference in crystal structure of the binaries (LaBr3 and LaI3) makes it difficult to grow high quality crystals of the ternary as the iodine concentration is increased. On the other hand, LaBrxCl3-x:Ce provides excellent performance. Its light output is high and it provides …
Date: January 23, 2006
Creator: Shah, Mr. Kanai; Higgins, Mr. William & Loef, Dr. Edgar V. Van
System: The UNT Digital Library
NOVEL CONCEPTS RESEARCH IN GEOLOGIC STORAGE OF CO2 PHASE III (open access)

NOVEL CONCEPTS RESEARCH IN GEOLOGIC STORAGE OF CO2 PHASE III

As part of the Department of Energy's (DOE) initiative on developing new technologies for storage of carbon dioxide in geologic reservoirs, Battelle has been investigating the feasibility of CO{sub 2} sequestration in the deep saline reservoirs in the Ohio River Valley region. In addition to the DOE, the project is being sponsored by American Electric Power (AEP), BP, The Ohio Coal Development Office (OCDO) of the Ohio Air Quality Development Authority, Schlumberger, and Battelle. The main objective of the project is to demonstrate that CO{sub 2} sequestration in deep formations is feasible from engineering and economic perspectives, as well as being an inherently safe practice and one that will be acceptable to the public. In addition, the project is designed to evaluate the geology of deep formations in the Ohio River Valley region in general and in the vicinity of AEP's Mountaineer Power Plant in particular, in order to determine their potential use for conducting a long-term test of CO{sub 2} disposal in deep saline formations. The current technical progress report summarizes activities completed for the October through December 2005 period of the project. As discussed in the following report, the main field activity was reservoir testing in the Copper …
Date: January 23, 2006
Creator: Gupta, Neeraj
System: The UNT Digital Library