Year
1996
Abstract
The UNted States Department of Energy (DOE) is evahu3ting options for rendering surplus inventories of highly enriched uranium (HEU) incapable of being used in nuclear weapons. Weapons-capable HEU was earlier produced by enriching the uranium isotope 23% tlom its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. NOW, by permanently diluting the concentration of the ‘~ isotope, the weapons capability of HEU can be eliminated in a manner that is reversible only through isotope reenrichment, and therefore, highly resistant to proliferation. To the extent that can be economically and technically justified, the down-blended, low-enriched uranium product will be made suitable for use as commercial reactor fhel. Such down-blended uranium product can also be disposed of as waste if chemical or isotopic impurities preclude its use as reactor fwl. The DOE has evaluated three candidate processes for dovm blending surplus HEU. These candidate processes are: (1) Uranium hexatluori& blending. (2) Molten uranium metal blending. (3) Uranyl nitmte solution blending. This paper &scribes each of these candidate processes. It also compares the relative advantages and disadvantages of each process with respect to (1) the various forms and compounds of HEU comprising the surplus inventory, (2) the use of down-blended product as commercial reactor tkl, or 3) it’s disposal as waste.