Approach on Component Selection for Ageing-Trend Analysis Within PSA Models

The major advantage of PSA is the possibility of in-depth qualitative and quantitative analysis of NPP actual configuration with definition of factors introducing a significant contribution to the general risk of reactor core damage. However main lack of the PSA current models is neglect of equipment ageing effects. Neglecting of ageing effects in PSA could lead to incorrectness of risk profile and influent on risk-informed decision making process. To solve this issue incorporation of ageing aspects into PSA models for Armenian NPP Unit 2 was initiated. Implementation of ageing trend analysis for all PSA components is insuperable effort, so the first step of the analysis is component selection activity. This paper is addressing the approach on component selection for ageing-trend analysis within PSA models. Presented approach is based on ageing effect and risk importance data. The procedure was developed and implemented in the framework of ageing aspects incorporation into PSA level 1 model for Armenian NPP Unit 2.