Analysis of core damage frequency: Peach Bottom, Unit 2 external events

This report presents the analysis of external events (earthquakes, fires, floods, etc.) performed for the Peach Bottom Atomic Power Station as part of the USNRC-sponsored NUREG-1150 program. Both the internal and external events analyses make full use of recent insights and developments in risk assessment methods. In addition, the external event analyses make use of newly-developed simplified methods. As a first step, a screening analysis was performed which showed that all external events were negligible except for fires and seismic events. Subsequent detailed analysis of fires resulted in a total (mean) core damage frequency of 1.95E-5 per year. The seismic analysis resulted in a total (mean) core damage frequency of 7.66E-5 per year using hazard curves developed by Lawrence Livermore National Laboratory and 3.09E-6 per year using hazard curves developed by the Electric Power Research Institute. Uncertainty analyses were performed, and dominant components and sources of uncertainty were identified. 71 refs., 63 figs., 54 tabs