Methodology for risk-based evaluation of emergency response planning

A number of processes and events directly related to offsite emergency planning considerations are modeled in a probabilistic risk assessment (PRA). The results, if properly evaluated and communicated, can provide valuable insights to emergency planners. The PRA analyzes various potential accident sequences; these analyses can be used to identify those few sequences that may require the initiation of emergency response activities. A PRA also models the effectiveness of selected operator actions in mitigating potential radioactive releases. Thus, PRA results can provide guidance valuable not only in assessing the effectiveness of emergency response alternatives but also in considering proposed revisions to emergency planning criteria. This paper presents the results of the methodology development phase of a two-phase Electric Power Research Institute (EPRI)-funded study of how PRA methods and results could be incorporated into the field of emergency planning. The objective of the study is to develop and demonstrate a methodology whereby the results from a completed PRA can be used to broaden the perspective with which certain elements of an emergency response plan are considered.