Level 1 probabilistic safety analysis of internal event in marine nuclear power plants

  Objectives  This paper uses the probabilistic safety analysis method to review the safety of marine nuclear power plants (MNPPs).

  Methods  The relevant data of nuclear power plant systems and equipment is referenced to establish a Level 1 probabilistic safety analysis (PSA) model of the internal event power conditions of MNPPs. For the 17 groups of initial events that may cause reactor core damage, 17 event trees are established, along with 42 fault trees for the eight front/support systems, and then conduct a Level 1 PSA analysis.

  Results  The core damage frequency (CDF) is calculated as 4.38×10^–6/(reactor year), and the contribution of each initial event group to the CDF is determined. According to importance analysis, human error events and power system faults are the two factors that contribute the most to the CDF of MNPPs. Sensitivity analysis finds that connecting a third diesel generator can considerably reduce the CDF.

  Conclusions  The results of this study can provide references for the safety design of MNPPs.