A Review of Multi-Unit Nuclear Power Plant Probabilistic Risk Assessment Research

The events at the Fukushima nuclear power station drew attention to the need for consideration of risks from multiple nuclear reactor units co-located at a site. As a result, considerable international interests and research efforts have been dedicated to addressing the multi-unit risks over the past few years. This paper presents a review of the state-of-the-art multi-unit probabilistic risk assessment (MUPRA) of nuclear power plants. The concept of MUPRA is briefly presented and the relevant activities to address and develop methodologies are summarized including workshops, proceedings, projects and case studies. The paper presents different facets of MUPRA research, including multi-unit event, MUPRA modeling and site-based risk metric. The paper also identifies existing gaps and the need for future research.