Application Of The Generic And Specific SPAR-CSN Probabilistic Safety Assessment Models

Resumen

Oversight of licensee's performance should be done from an independent position. This position is best achieved when the regulatory body develops its own methodologies and tools. In particular, in the case of probabilistic safety analysis (PSA), the large number of hypotheses and assumptions behind the model makes it very difficult to perform sound regulatory analyses using licensee models. Therefore, the development of a PSA model to be used by the regulator provides a better understanding of the risks of nuclear power plants and an improvement of the regulatory practice, at the same time enhancing consistency of the risk perspective across regulatory actions.

In this context, the Spanish Regulatory Body (CSN), in collaboration with the Universidad Politécnica de Madrid (UPM), has been developing its own models: first a standardized generic Standardized Plant Analysis Risk model (SPAR-CSN) for a PWR-WEC, 3-loop design that serves as the basis for the development of a specific model of one of the Spanish PWR-WEC, 3-loop design. The development of both SPAR models has been applied to the analysis of two actual incidents, from a risk point of view. The results obtained have led to the identification of safety-critical systems and components.