Abstract Probabilistic Risk Assessment (PRA) is a systematic methodology to estimate risk for complex systems such as nuclear power plants. In the nuclear engineering domain, PRA originated from the Reactor Safety Study in 1975. Over the past decades, PRA has been widely utilized by the U.S. Nuclear Regulatory Commission (NRC) and the nuclear industry as input to risk-informed decision-making. The evolution of the PRA methodology has been driven by the expansion of PRA usage. The initial focus was to calculate safety risk and prioritize systems and components based on their risk significance. After the 2000s, the purpose of PRA usage shifted to improving operational efficiency while maintaining safety. To support this transition, the capabilities of PRA are being extended to enable forward-looking “what-if” analyses that can compare the risk impacts of operational alternatives. Toward this direction, our research has developed an Integrated PRA (I-PRA) methodology, making two contributions: (i) advancing a coupling method between physical simulations and human performance models by creating a bi-directional, scenario-based input-output exchange and (ii) developing a computational interface equipped with uncertainty quantification and dependency treatment to incorporate the coupled physics-human simulation into plant PRA. While the I-PRA has been applied to various hazards and scenarios, this presentation shows an example of Fire I-PRA and its application to an industry case study.

International Association for Probabilistic Safety Assessment and Management (IAPSAM). Tatsuya earned his Ph.D. in nuclear engineering from the University of Illinois at Urbana-Champaign in 2018. He received his M.S. in nuclear engineering and B.S. in system engineering (with a concentration in environment and energy systems engineering) from the University of Tokyo, Japan, in 2013 and 2011, respectively.