CONFIGURATION OF RISK MONITOR SYSTEM BY PLANT DEFENSE-IN-DEPTH MONITOR AND RELIABILITY MONITOR

摘要

A new method of risk monitor system of a nuclear power plant has been proposed from the aspect by what degree of safety functions incorporated in the plant system is maintained by multiple barriers of defense-in-depth (DiD). Wherein, the central idea is plant DiD risk monitor and reliability monitor derived from the four aspects of (i) design principle of nuclear safety to realize DiD concept, (ⅱ) definition of risk and risk to be monitored, (ⅲ) severe accident phenomena as major risk, (ⅳ) scheme of risk ranking, and (ⅴ) dynamic risk display. In this paper, the overall frame of the proposed frame on risk monitor system is summarized and the detailed discussion is made on the definitions of major terminologies of risk, risk ranking, anatomy of fault occurrence, two-layer configuration of risk monitor, how to configure individual elements of plant DiD risk monitor and its example application for PWR safety system.