A Probabalistic Approach to Safety System Evaluation: An Example Involving Application of Monte Carlo Techniques

Abstract

This paper describes a probabilistic approach to evaluating shut-down system capability for a postulated set of Loss of Regulation (LOR) incidents. Shutdown system unavailabilities are calculated as a function of Regional Overpower Trip (ROPT) system setpoints. A mathematical model of the Bruce GS 'A' ROPT system is developed. In this model random effects are treated by using a Monte Carlo simulation technique. Preliminary results are presented, and the sensitivity of shutdown system unavailabilities to key parameters is discussed.