Study on Importance Analysis and Uncertainty Analysis of Fire Probabilistic Safety Assessment in Domestic Nuclear Power Plants

Abstract

In Korea, the first of fire Probabilistic Safety Assessment (PSA) was conducted for Hanbit nuclear power plant in 1992. The fire probabilistic safety assessment of a domestic power plant was applied to the methodology and data presented in TR-105928 published in 1995 by EPRI, which separately addresses accident scenarios and conditional core damage frequency. In terms of importance analysis, they performed only a rough assessment of fire area and detailed scenarios that can have a significant impact on the Core Damage Frequency (CDF), but they do not perform uncertainty analysis. In this paper, we present a method for performing importance analysis and uncertainty analysis through a combination of the Minimum Cut Set (MCS) resulting in core damage to nuclear power plants and basic events that form an accident scenario. Based on this, we also presented insights into the basic events that were significantly derived from the fire event probabilistic safety assessment through analysis of switchgear rooms in reference nuclear power plants, and conducted a uncertainty analysis of the CDF. This paper is expected to be available for future Risk-Informed Decision Making (RIDM).