(GRS 098) Safety Analysis for Boiling Water Reactors - A Summary

After completing the German Risk Study for pressurised water reactors, the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) has now conducted for the first time a probabilistic safety analysis for boiling water reactors (BWR) on behalf of the Federal Minister for Research and Technology (BMFT). Reactor safety is constantly developed in line with research findings and operating experience. Thus reactor safety is a dynamic process in which safety analyses play an important role. Probabilistic safety analyses determine the frequency of certain events (e.g. leaks in pipes) and the failure probabilities of the safety systems needed to control such events. The failure of safety systems initially leads to a hazard to the cooling of the reactor core. When such hazard states occur, there are accident management measures which can still be carried out in order to prevent core melt. The particular aim of this analysis is to examine and evaluate the balance of the safety-related technology, to suggest safety-related improvements, and to show the possibilities of accident-management measures at severe accidents.