Qualitative review of probabilistic safety assessment characteristics

Plant specific Probabilistic Safety Assessments (PSAs) constitute a major part of the present Swedish periodic safety review. The results of the analyses are to be reported to the Swedish government in a document given the acronym ASAR (As operated Safety Analysis Report). The basic studies are limited to the core damage level (level 1 PRA); the Swedish PSAs have been generated in a relatively short period of time. The reviews of the studies, carried out by Swedish Nuclear Power Inspectorate (SKI), clearly indicate significant differences in scope, degree of detail, coverage etc. Application of a broad spectrum of methods and assumptions has given a major impact on the results of PSAs, which complicates a proper comparison. Having this as a background SKI initiated in 1986 the SUPER-ASAR project. (orig./HSCH)