Probabilistic Safety Analysis for Loss of Offsite Power Accident in Dual-units Nuclear Power Plant

Wanxin Feng,Mingzhu Zhang,Zhixin Xu,Yu Yu,L Duan,A.Z Abdullah

doi:10.1051/e3sconf/202124501015

Abstract

In order to explore the risk assessment method of the multi-unit nuclear power plant site, this paper selects the dual-unit plant nuclear site to analyze lose off-site power accident. By combining and improving the single-unit ET/FT model, to establish the dual-unit ET/FT model. From the analysis of the accident sequence, it can be concluded that the common cause failure of equipment is the main challenge faced by the dual-units. Especially the RPC sub-channel in the reactor protection system and the failure of emergency diesel engine circuit breaker. As can be seen from the high proportion of core CD occurring simultaneously in both uints, it has a great significance to study the risk of mult-units sites.

Highlights

Traditional nuclear power plant Probabilistic Safety Assessments (PSA) are conducted for the single reactor, but the reality is that the vast majority of nuclear power plants currently in operation or under construction are multi-unit sites
The dual-reactor PSA model is used to carry out probabilistic safety analysis on the Loss of Offsite Power (LOOP) accident of the double-units plant site
From the analysis of the accident sequence, it can be concluded that the common cause failure of equipment is the main challenge faced by the double-units

Summary

Introduction

Traditional nuclear power plant Probabilistic Safety Assessments (PSA) are conducted for the single reactor, but the reality is that the vast majority of nuclear power plants currently in operation or under construction are multi-unit sites. Since the Fukushima disaster, the international community has paid great attention to the risk assessment of multi-unit sites[1]. Multi-units sites risk assessment will contribute to the comprehensive safety improvement of nuclear power plants[2]. PSA a system engineering method developed after the 1970s, adopts FT/ET ( fault tree analysis, event tree analysis) and probabilistic risk analysis method to comprehensively analyse various possible accidents of complex systems, and comprehensively consider the probability of the accidents and its consequences. Probabilistic safety analysis is a standard tool for nuclear power plant safety assessment[3]. We can improve the single-unit probabilistic safety analysis method to analyse multi-unit sites

Methods

Results

Conclusion