DUF6 Materials Use Roadmap

Haire, M.J.

Oak Ridge National Laboratory

关键词: Uranium Hexafluoride;    Carbon Steels;    National Government;    Isotope Separation;    Gaseous Diffusion Plants;   

DOI  :  10.2172/885886
RP-ID  :  ORNL-6968
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  885886

美国|英语

来源: UNT Digital Library

【 摘 要 】

The U.S. government has {approx}500,000 metric tons (MT) of surplus depleted uranium (DU) in various chemical forms stored at U.S. Department of Energy (DOE) sites across the United States. This DU, most of which is DU hexafluoride (DUF{sub 6}) resulting from uranium enrichment operations, is the largest amount of nuclear material in DOE's inventory. On July 6, 1999, DOE issued the ''Final Plan for the Conversion of Depleted Uranium Hexafluoride as required by Public Law 105-204'', in which DOE committed to develop a ''Depleted Uranium Hexafluoride Materials Use Roadmap'' in order to establish a strategy for the products resulting from conversion of DUF{sub 6} to a stable form. This report meets the commitment in the Final Plan by providing a comprehensive roadmap that DOE will use to guide any future research and development activities for the materials associated with its DUF{sub 6} inventory. The Roadmap supports the decision presented in the ''Record of Decision for Long-Term Management and Use of Depleted Uranium Hexafluoride'', namely to begin conversion of the DUF{sub 6} inventory as soon as possible, either to uranium oxide, uranium metal, or a combination of both, while allowing for future uses of as much of this inventory as possible. In particular, the Roadmap is intended to explore potential uses for the DUF{sub 6} conversion products and to identify areas where further development work is needed. It focuses on potential governmental uses of DUF{sub 6} conversion products but also incorporates limited analysis of using the products in the private sector. The Roadmap builds on the analyses summarized in the recent ''Programmatic Environmental Impact Statement for Alternative Strategies for the Long-Term Management and Use of Depleted Uranium Hexafluoride''. It also addresses other surplus DU, primarily in the form of DU trioxide and DU tetrafluoride. The DU-related inventory considered here includes the following: (1) Components directly associated with the DUF{sub 6} presently being stored at gaseous diffusion plant sites in Paducah, Kentucky; Portsmouth, Ohio; and Oak Ridge, Tennessee--470,500 MT of DU, 225,000 MT of fluorine chemically combined with the DU, and 74,000 MT of carbon steel comprising the storage cylinders; (2) Approximately 27,860 MT of DU in the form of uranium trioxide, tetrafluoride, and various other forms containing varying amounts of radioactive and chemical impurities, presently stored primarily at DOE's Savannah River Site. This Roadmap characterizes and analyzes alternative paths for eventual disposition of these materials, identifies the barriers that exist to implementing the paths, and makes recommendations concerning the activities that should be undertaken to overcome the barriers. The disposition paths considered in this roadmap and shown in Fig. ES.1 are (a) implementation of cost-effective and institutionally feasible beneficial uses of DU using the products of DUF{sub 6} conversion and other forms of DU in DOE's inventory, (b) processing the fluorine product resulting from DUF{sub 6} conversion to yield an optimal mix of valuable fluorine compounds [e.g., hydrogen fluoride (hydrofluoric acid), boron trifluoride] for industrial use, and (c) processing emptied cylinders to yield intact cylinders that are suitable for reuse, while maintaining an assured and cost-effective direct disposal path for all of the DU-related materials. Most paths consider the potential beneficial use of the DU and other DUF{sub 6} conversion products for the purpose of achieving overall benefits, including cost savings to the federal government, compared with simply disposing of the materials. However, the paths provide for assured direct disposal of these products if cost-effective and institutionally feasible beneficial uses are not found.