A COMPREHENSIVE DATABASE APPLICATION TO SUPPORT SEISMIC PSA MODELING

摘要

The German PSA Guideline and its technical document on PSA methods published in 2005 require probabilistic safety analyses (PSA) to be carried out in the frame of periodic safety reviews for nuclear power plants. This also includes a seismic PSA (SPSA) for sites with design earthquake intensities exceeding the value VII (MSK or EMS scale). Based on the specifications in the PSA Guideline, a comprehensive database is conceived, which can be used for performing and applying SPSA. can be also applied as a tool in the frame of SPSA reviews for all queries regarding the plant specific SPSA to be evaluated. Some enlargements and concretions of the requirements in the PSA Guideline were implemented to ensure an adequate quality as well as the traceability and reproducibility of a SPSA. Therefore, a two-stage screening process of structures, systems and components (SSC) is developed that may be used to compile and complete the seismic equipment list (SEL). Moreover, the seismic robustness of all SSC of the SEL can be evaluated with respect to their safety significance. In addition, a general model is developed for modeling dependencies of seismic failures for different SSC. It is planned to configure for an automatic parameter transfer (e.g. fragilities of all SSC of the SEL and correlation parameters for the description of seismic dependent SSC failure behavior) in order to quantify the plant model for arbitrary seismic intensities. The paper outlines the detailed structure of the database. The application of during accomplishment of the SSC screening process, for description and modeling of dependencies and, finally, for quantification of the plant model is elucidated by means of selected examples.