Evaluation of DUF{sub 6}-G-Q-STU-001 (ALARA analysis supporting approval of authorized limits).

Abstract

The U.S. Department of Energy (DOE) has selected Uranium Disposition Services, LLC (UDS) to proceed with disposition of the inventory of depleted uranium hexafluoride (DUF{sub 6}) for which DOE has management responsibility. To accomplish this task, UDS will construct and operate facilities at two DOE-owned sites, one near Paducah, Kentucky, and another near Portsmouth, Ohio, to convert DUF{sub 6} to uranium oxide (principally U{sub 3}O{sub 8}). The off-gas treatment system for the conversion process will produce aqueous hydrogen fluoride (AqHF), also known as hydrofluoric acid, and a relatively small amount of calcium fluoride (CaF{sub 2}), each containing some residual radioactive material. As part of its contractual charge, UDS must identify and implement a disposition for all three products generated by the DUF{sub 6} conversion facilities: uranium oxide, AqHF, and CaF{sub 2}. The UDS DUF{sub 6} Conversion Product Management Plan (DUF{sub 6}-UDS-PLN-004, September 2003) concludes that a viable commercial market exists for AqHF, which, if not sold, would have to be neutralized, producing a relatively large quantity of additional CaF{sub 2}. Although CaF{sub 2} has very limited market potential, there is some possibility that it also could be sold. If these potential markets could be developed, DOE would save the costs of neutralizing AqHF and/or disposing of the CaF{sub 2} neutralization product. Accordingly, UDS has decided to seek approval from DOE for unrestricted release of both AqHF and CaF{sub 2} that would be generated if AqHF could not be sold or if sales were interrupted. If AqHF were sold, the relatively small quantity of CaF{sub 2} still being generated by the DUF{sub 6} conversion process off-gas treatment system would most likely be disposed of as waste. The main product of conversion, depleted uranium oxide, will be reused to the extent possible or disposed of as waste, if no practical reuse option is found.