Towards a PSA harmonization. French-Belgian comparison of the level 1 PSA for two similar PWR types

P. Dupuy, F. Corenwinder, J.M. Lanore, D. Gryffroy, P. de Gelder, M. Hulsmans, PSAM6 conference, Puerto Rico, juin 2002, Rapport IRSN-DES/518

In the framework of the cooperation between French and Belgian regulatory authorities, a PSA comparison exercise has been carried out for several years. This comparison deals with two PSA level 1 studies for internal events, performed for both power and shutdown states : the French PSA of the 900 MWe-series PWR, and the Belgian PSA of the Tihange 1 PWR, which both concern PWRs with a similar Framatome design. The purpose of this paper is to describe the PSA comparison methodology and to present, in a qualitative way, an overview of the insights obtained up to now. It also shows that such an “a posteriori” benchmark exercise turns out to be a step towards PSA harmonization, and gives more confidence in the results of plant specific PSA when used for applications like precursor analysis or evaluations of importance to safety.