The Effects of Mitigative Strategies on SBO Severe Accidents in the KSNP

The purpose of this analysis is to evaluate the effects of safety systems or mitigative strategies on the progression of severe accidents. The Korean standard nuclear power plant (KSNP) has been selected as a reference plant, and the eight station blackout sequences, which are the most likely scenarios based on the probabilistic safety analysis of the KSNP, have been determined as base cases. These eight sequences account for 99 percent of the occurrence frequency of a total of 197 station blackout accident scenarios. Furthermore, an additional evaluation for the strategy of a primary feed and bleed strategy has been performed as sensitivity cases. Thermal hydraulic analyses have been done by using MAAP version 4.06