Containment Performance Analysis for the Korean Standard Nuclear Power Plant with Recovery Action between Core Damage and Containment Failure

摘要

According to the containment performance analysis for the internal events of the Ulchin nuclear power plant units 3,4, which are Korean standard nuclear power plants (KSNP), many hours were identified to be available between core damage and containment failure. Therefore taking recovery actions during these time periods is considered to mitigate the accident progression. In the base case, a recovery of offsite AC power subsequent to core damage is only considered for the station blackout sequences. In this paper, the New Non-recovery Probability and Human Error Probability, based on MAAP calculation of the time interval from core damage to containment failure, were applied in order to calculate the new containment failure probability. The conditional probability of containment failure for internal core damage was obtained at 0.251 for the base case and 0.238 with the recovery action. The new analysis results show a 5.2% decrease in conditional containment failure probability.