THE ROLE OF PROBABILISTIC LIMITS FOR THE ASSESSMENT OF THE SAFETY OF NUCLEAR-POWER-PLANTS

Probabilistic safety assessment (PSA) provides quantitative informatio n on the probability of event sequences relevant to plant safety. Crit eria for PSA results can be defined and implemented into the regulator y process. This process is presented on the international scale for OE CD member states. In practically all of the countries PSA is used to a great extent. Limits are available for core damage frequency and the frequency of large releases but on different levels of obligation rang ing from recommendations to regulatory requirements In general the lim it values are imbedded into substantially different regulatory schemes so that the isolated comparison or discussion of limits can lead to w rong conclusions.