Does new source term information change the regulations

Although revised source terms valid for all reactor types and accident sequences cannot be defined at this time, the accumulation of substantial new information on the subject compels us to reevaluate those regulations, standards and practices which are based on such estimates. We have no real choice in the matter, the technical information now available shows the old TID-14844 source term to be simply wrong, not even a good surrogate, and the WASH-1400 source terms, although of the right form, to be only useful as the bounds of the span of interest, ranging from essentially unmitigated core melts to well mitigated ones. A review of existing areas of regulatory practice influenced by accident source terms was used to identify areas where the NRC staff concludes changes may be appropriate. Six areas are identified and discussed in this paper. For each area identified, a description of the background and current practice, possibility for and character of potential changes in practice, costs, and benefits follows