Plant Specific Risk Informed Decision Making for Light Water Reactors (VVER-1000, KKNPP-1&2 in India)

The paper gives an overview of PSA applications as Plant Specific Risk Informed Decision Making in a typical VVER, 1000MWe Light Water Reactor and covers a case study on the analysis of impact on Core Damage Frequency (CDF) due to unavailability of system/equipment for Light Water Reactors (LWR). In light water reactors, during power operation if any one safety train becomes unavailable for more than allowed outage time (AOT) due to maintenance or repair, then reactor has to be shut down. In this case study, due to the unavailability of one safety train, impact on CDF was calculated and it was found to be within the acceptable range as prescribed in International Standard. Based on this study, it was concluded that the given methodology can be served as a risk informed decision making tool for LWR reactor.