ABSTRACT
I&C systems in NPPs are being digitalized by adopting new features, such as software, fault-tolerant techniques, and network communication. Although the risk caused by these new features should be analyzed in an appropriate framework, at present there is no consensus on PSA methods for them. In this study, a general frame of a PSA model for the automatic safety signal generation function in a DI&C system is proposed, in consideration of the representative safety features of this system and the linkage between them. Through the related literature, we identified the requirements to construct the DI&C PSA model, constructed a general frame reflecting its possible parts, and specified the assumptions and approaches applied in this process. Although this study has focused on a qualitative approach because an appropriate database cannot be obtained yet, important failure modes that are understood in this current phase, and the research topics that need to be considered for the development of the enhanced DI&C PSA model, are summarized.
