Expert Perceptions on Human Reliability Analysis for Advanced Reactors

Advanced Power-reactors will deploy more automation, some will be remote operated, need little or no human intervention, utilize varying passive safety systems, and in many cases, operate as multiple units controlled from a single main control room. These and many other features make them significantly different from the conventional power reactors we use today. Human reliability analysis (HRA) methods were developed mainly for the conventional reactors and thus may have to be revisited for suitability for advanced reactors if HRA is at all necessary in these unique contexts. We embarked on a study to interact with 28 experts in the fields of probabilistic safety analysis, human factors, and human reliability analysis across six countries. These experts were affiliated with research institutions, nuclear regulatory bodies, nuclear utilities, technical support organizations, and universities. The results of the study have been organized into operational risks, relevance of HRA, new scenarios and performance shaping factors, organizational approach to HRA, research questions, and open-ended thoughts on HRA for Advanced Reactors. The results highlight that human factors considerations for advanced reactors differ significantly from those associated with conventional designs, thereby presenting new challenges for HRA. Notably, there remains a knowledge gap among experts regarding the operational reliability of the novel systems used in advanced reactors. This uncertainty may contribute to scepticism about the reduced human influence on plant safety often claimed by advanced reactor vendors. While opinions on the role of HRA in advanced reactors vary, there is considerable agreement on key human factor concerns. Overall, the insights from this study offer preliminary guidance for adapting HRA methodologies to advanced reactor contexts, identifying attributes that may inform the development of suitable HRA approaches.

Keywords: Human reliability analysis, safety assessment, advanced reactors, small modular reactors, human factors.