Evaluation of Impact of NEK Safety Upgrade Program Implementation on the Reduction of Total Core Damage Frequency

The nuclear accident in Japanese plants 2011 has initiated a quick response from the countries utilizing power. Krsko Nuclear Power Plant (NEK) was required by Slovenian Safety Administration (SNSA) to perform consequential actions reduce risk of severe accidents and their consequences as low feasible. NEK have analyzed accidents, based on results this analysis, proposed measures be implemented shortest possible time. In SNSA request developed Upgrade Program (SUP) which contains comprehensive set for plant safety improvements. SUP Phase 1 been during Outage 2013. This paper presents work done evaluation impact modifications planned implementation Phases 2 3 quantitative figure merit significance – total core damage frequency (CDF). A most valuable terms contribution CDF reduction determined new fractional initiators categories obtained. quantification made employment RiskSpectrum PSA code running predefined analytical cases all initiator covered scope model. basis analysis NEK’s recent at-power model reflects status with modernization 1. two steps. first step were addressed second upgrades modeled addition those already modelled step.