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Depleted Uranium Hexafluoride Management Program. The technology assessment report for the long-term management of depleted uranium hexafluoride. Volume 1

Description: With the publication of a Request for Recommendations and Advance Notice of Intent in the November 10, 1994 Federal Register, the Department of Energy initiated a program to assess alternative strategies for the long-term management or use of depleted uranium hexafluoride. This Request was made to help ensure that, by seeking as many recommendations as possible, Department management considers reasonable options in the long-range management strategy. The Depleted Uranium Hexafluoride Management Program consists of three major program elements: Engineering Analysis, Cost Analysis, and an Environmental Impact Statement. This Technology Assessment Report is the first part of the Engineering Analysis Project, and assesses recommendations from interested persons, industry, and Government agencies for potential uses for the depleted uranium hexafluoride stored at the gaseous diffusion plants in Paducah, Kentucky, and Portsmouth, Ohio, and at the Oak Ridge Reservation in Tennessee. Technologies that could facilitate the long-term management of this material are also assessed. The purpose of the Technology Assessment Report is to present the results of the evaluation of these recommendations. Department management will decide which recommendations will receive further study and evaluation. These Appendices contain the Federal Register Notice, comments on evaluation factors, independent technical reviewers resumes, independent technical reviewers manual, and technology information packages.
Date: June 30, 1995
Creator: Zoller, J.N.; Rosen, R.S. & Holliday, M.A.
Partner: UNT Libraries Government Documents Department

Depleted Uranium Hexafluoride Management Program. The technology assessment report for the long-term management of depleted uranium hexafluoride. Volume 2

Description: With the publication of a Request for Recommendations and Advance Notice of Intent in the November 10, 1994 Federal Register, the Department of Energy initiated a program to assess alternative strategies for the long-term management or use of depleted uranium hexafluoride. This Request was made to help ensure that, by seeking as many recommendations as possible, Department management considers reasonable options in the long-range management strategy. The Depleted Uranium Hexafluoride Management Program consists of three major program elements: Engineering Analysis, Cost Analysis, and an Environmental Impact Statement. This Technology Assessment Report is the first part of the Engineering Analysis Project, and assesses recommendations from interested persons, industry, and Government agencies for potential uses for the depleted uranium hexafluoride stored at the gaseous diffusion plants in Paducah, Kentucky, and Portsmouth, Ohio, and at the Oak Ridge Reservation in Tennessee. Technologies that could facilitate the long-term management of this material are also assessed. The purpose of the Technology Assessment Report is to present the results of the evaluation of these recommendations. Department management will decide which recommendations will receive further study and evaluation.
Date: June 30, 1995
Creator: Zoller, J.N.; Rosen, R.S. & Holliday, M.A.
Partner: UNT Libraries Government Documents Department

Modeling Creep Rupture of Zirconium Alloys

Description: Safe interim dry storage of spent nuclear fuel (SNF) must be maintained for a minimum of twenty years according to the Code of Federal Regulations. The most important variable that must be regulated by dry storage licensees in order to meet current safety standards is the temperature of the SNF. The two currently accepted models to define the maximum allowable storage temperature for SNF are based on a diffusion controlled cavity growth (DCCG) failure mechanism for the cladding. Although these models are based on the same fundamental failure theory (DCCG), the researchers who developed the models made different assumptions, including selection of some of the most critical variables in the DCCG failure equation. These inconsistencies are discussed together with recommended modifications to the failure models based on recent data.
Date: April 8, 2000
Creator: Rosen, R.S. & Hayes, T.A.
Partner: UNT Libraries Government Documents Department

Steady State Creep of Zirconium at High and Intermediate Temperatures

Description: Creep of zirconium and zirconium alloys has been labeled ''anomalous.'' Researchers often report that zirconium and its alloys never reach true steady state creep and have stress exponents that continuously change with stress and temperature. Many varied interpretations have been offered explaining the creep behavior of zirconium. Some have suggested that creep is diffusion controlled, while others maintain that creep is dislocation glide controlled. Cumulative zirconium creep data will be presented based on an extensive literature review. An interpretation of results will be presented and compared to previous interpretations.
Date: April 8, 2000
Creator: Rosen, R.S. & Hayes, T.A.
Partner: UNT Libraries Government Documents Department

Elastic incompatibility stresses across planar and nonplanar grain boundaries in silver, aluminum, and zirconium applied to ductile fracture criteria under high triaxial stress

Description: Grain boundaries in a polycrystal imply elastic incompatibilities that can lead to stress states in the vicinity of the interface that are different from the macroscopic or applied stresses because the single crystal elastic properties are not all isotropic. This phenomenon is important as mechanical processes may operate at the microscopic level that would not be predicted based on the macroscopic stress state. This phenomenon has not been widely examined. One of the few studies that examined the level of stress- state modification on copper determined that slip or plasticity in cyclically deformed copper occurred in areas with high elastic incompatibility stresses. The focus of the present study is the unstable growth of cavities as a result of high local triaxial stress. Grain boundaries in silver, aluminum, and zirconium are examined.
Date: July 1, 1996
Creator: Roehnelt, R.; Kassner, M.E.; Kennedy, T.C. & Rosen, R.S.
Partner: UNT Libraries Government Documents Department

Characterization of options and their analysis requirements for the long-term management of depleted uranium hexafluoride

Description: The Department of Energy (DOE) is examining alternative strategies for the long-term management of depleted uranium hexafluoride (UF{sub 6}) currently stored at the gaseous diffusion plants at Portsmouth, Ohio, and Paducah, Kentucky, and on the Oak Ridge Reservation in Oak Ridge, Tennessee. This paper describes the methodology for the comprehensive and ongoing technical analysis of the options being considered. An overview of these options, along with several of the suboptions being considered, is presented. The long-term management strategy alternatives fall into three broad categories: use, storage, or disposal. Conversion of the depleted UF6 to another form such as oxide or metal is needed to implement most of these alternatives. Likewise, transportation of materials is an integral part of constructing the complete pathway between the current storage condition and ultimate disposition. The analysis of options includes development of pre-conceptual designs; estimates of effluents, wastes, and emissions; specification of resource requirements; and preliminary hazards assessments. The results of this analysis will assist DOE in selecting a strategy by providing the engineering information necessary to evaluate the environmental impacts and costs of implementing the management strategy alternatives.
Date: December 1995
Creator: Dubrin, J. W.; Rosen, R. S.; Zoller, J. N.; Harri, J. W. & Schwertz, N. L.
Partner: UNT Libraries Government Documents Department

Critical Analysis of Dry Storage Temperature Limits for Zircaloy-Clad Spent Nuclear Fuel Based on Diffusion Controlled Cavity Growth

Description: Interim dry storage of spent nuclear fuel (SNF) rods is of critical concern because a shortage of existing SNF wet storage capacity combined with delays in the availability of a permanent disposal repository has led to an increasing number of SNF rods being placed into interim dry storage. Safe interim dry storage must be maintained for a minimum of twenty years according to the Standard Review Plan for Dry Cask Storage Systems [1] and the Code of Federal Regulations, 10 CFR Part 72 [2]. Interim dry storage licensees must meet certain safety conditions when storing SNF rods to ensure that there is a ''very low probability (e.g. 0.5%) of cladding breach during long-term storage'' [1]. Commercial SNF typically consists of uranium oxide pellets surrounded by a thin cladding. The cladding is usually an {alpha}-zirconium based alloy know as ''Zircaloy''. In dry storage, the SNF rods are confined in one of several types of cask systems approved by the Nuclear Regulatory Commission (NRC). ''The cask system must be designed to prevent degradation of fuel cladding that results in a type of cladding breach, such as axial-splits or ductile fracture, where irradiated UO{sub 2} particles may be released. In addition, the fuel cladding should not degrade to the point where more than one percent of the fuel rods suffer pinhole or hairline crack type failure under normal storage conditions [1].'' The NRC has approved two models [3,4] for use by proposed dry storage licensees to determine the maximum initial temperature limit for nuclear fuel rods in dry storage that supposedly meet the above criteria and yield consistent temperature limits. Though these two models are based on the same fundamental failure theory, different assumptions have been made including the choice of values for material constants in the failure equation. This report will examine ...
Date: December 1, 1999
Creator: Hayes, T.A.; Rosen, R.S. & Kassner, M.E.
Partner: UNT Libraries Government Documents Department

Thermal stability of Mo/Si multilayers

Description: The thermal stability of Mo/Si multilayers for x-ray mirror applications was investigated by annealing studies at relatively low temperatures for various times. The as-deposited and annealed multilayers were examined using conventional small and large angle x-ray diffraction, normal incidence x-ray reflectance measurements using a synchrotron source, selected area electron diffraction, and high-resolution electron microscopy. The as-deposited structure consists of pure layers of crystalline Mo and amorphous Si separated by thin regions of amorphous Mo-Si. At temperatures between 200--400{degrees}C, the amorphous Mo-Si interlayers grow and hexagonal MoSi{sub 2} forms by a thermally activated process(es), and the bilayer spacing and x-ray reflectivity decrease. A determination of the effective activation energy of the process(es) suggests long-term stability at the mirror operating temperature, although additional low temperature testing is warranted. 11 refs., 5 figs., 2 tabs.
Date: July 1, 1991
Creator: Rosen, R.S.; Stearns, D.G. (Lawrence Livermore National Lab., CA (United States)); Viliardos, M.A.; Kassner, M.E. (Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering) & Vernon, S.P. (Vernon Applied Physics, Torrance, CA (United States))
Partner: UNT Libraries Government Documents Department