Pilot study: Analysis of prescribed test intervals at Oskarshamn 2

This report describes the used methods and the results from an analysis of test intervals carried out with the LPSA model for Oskarshamn 2 (LPSA-02). The analysis was made under a contract with OKG, department SR. The LPSA model is basically a normal PSA model, but with aim of calculating the current risk instead of average risk. The ability of the LPSA model to realistically calculate the influence of surveillance tests on risk is used to analyze test intervals. The primary purpose of this analysis is to demonstrate how LPSA can be used to analyze test intervals. This analysis is to be regarded as a first step in a more complete test interval analysis. The analysis aims at identifying test series that are more efficient than those prescribed in the current Technical Specifications. Test schemes have been identified, given by the scope, that are considerable more efficient than the existing test scheme prescribes by the Technical specifications. The results are tentative and generated within the scope and limitation given for this pilot study. The following continuation is recommended: Include Fire events; other hazard states than core damage should be analyzed; uncertainly analysis. (author). 5 refs, 3 tabs, 7 diagrams