Role and opportunitiy of Nuclear I&C under the changing regulatory environment in South Korea

In the licensing process for Nuclear Power Plants (NPPs) in South Korea, Probabilistic Safety Assessment (PSA) has been supplementary and the Risk-Informed Applications (RIAs) of which the core method is PSA were also carefully and limitedly utilized. However PSA became mandatorily incorporated into Safety Analysis Report and Periodic Safety Review, so the technical position of PSA is getting more significant in terms of width as well as depth. Meanwhile, the role and opportunity of nuclear Instrumentation and Control (I&C) is worthwhile to be highlighted in developing more credible PSA models. Particularly, it is expected that the information technology (i.e. software) embedded in digital I&C systems can adjust over- and under conservatism in analyzing risk. In this study, authors analyzed the PSA models for Korean Standard NPPs and proposed the possible accident scenarios which would be able to significantly reduce risk if advanced information technologies are applied. In regard, the enabling techniques for failure rate uncertainty reduction, component unavailability reduction, and human error (omission and commission) reduction are proposed. In order to improve the commercial competitiveness of NPPs, the collaboration and synergetic outcome of nuclear I&C and PSA needs to be more emphasized.