A Seismic Probabilistic Safety Assessment (SPSA), unlike other internal or external event analyses, has a very high probability of basic events when a strong earthquake occurs. Because of this high probability, the Core Damage Frequency (CDF) might be overestimated by the Rare Events Approximation (REA) and Minimal Cutset Upper Bound (MCUB) method for general quantitative analysis. To compensate for this overestimation, the exact CDF value can be derived with post-processing software such as an Advanced Cutset Upper Bound Estimator (ACUBE) or Fault Tree Evaluation using Monte Carlo simulation (FTeMC). However, the Minimal Cut Sets (MCSs), which has the same result as the calculated CDF, cannot be derived with both methods. In this paper, we propose a Monte Carlo Simulation Allocation Method (MCSAM) to derive the exact CDF and MCSs. We expect that the MCSAM will easily identify the plant's vulnerabilities to review the exact MCSs consistent with CDF results without additional post-processing or Monte Carlo Simulation.

与其他内部或外部事件分析不同，地震概率安全评估（SPSA）在发生强烈地震时具有很高的发生基本事件的可能性。由于这种可能性很高，因此对于一般的定量分析，“稀有事件近似”（REA）和“最小割集上限”（MCUB）方法可能会高估核心损坏频率（CDF）。为了补偿这种过高的估计，可以使用后处理软件（例如高级割集上限估计器（ACUBE）或使用蒙特卡洛模拟（FTeMC）的故障树评估）来得出确切的CDF值。但是，使用两种方法都无法得出与计算出的CDF相同的结果的最小割集（MCS）。在本文中，我们提出了一种蒙特卡洛模拟分配方法（MCSAM），以得出精确的CDF和MCS。