Preliminary worst-case accident analysis to support the conceptual design of a potential repository in tuff

The Nevada Nuclear Waste Storage Investigations (NNWSI) Project is conducting investigations to determine the suitability of a site at Yucca Mountain for development as a high level waste repository. In support of the conceptual design, a preliminary analysis has been performed to identify events that could cause radiological releases from the surface facilities during the operations period. Accidental releases were modeled as short-duration release plumes, dispersed under averaged climatic conditions, using the AIRDOS-EPA code. The consequences of these accidents, in 50-yr integrated dose commitments to operations personnel, to the maximally exposed member of the public, and to the general population in the surrounding area were calculated. The risk to the general public from each event was also assessed. All postulated accidents result in doses to members of the public that are lower than the 0.5 rem/accident limit set by the NRC in 10 CFR 60. For those accidents that do not involve both fire and breach of waste canisters, doses to operations personnel are within the NRC limit for routine operations of 5 rem/yr set in 10 CFR 20. Accidents that involve fire and breach of waste canisters may cause doses to some operations personnel that are in excess of this limit. 18 references, 1 figure, 3 tables