Application of internal fire probabilistic risk assessment in design optimization for marine SMR

Abstract Small Modular Reactors (SMR) have attracted more and more attention. It can provide economic, stable and clean power for remote areas. It is also a reliable solution in satisfying the power supply of small and medium grids, as well as comprehensive energy supply including heat, electricity, water and steam, and distributed energy supply. Internal Fire Probabilistic Risk Assessment (PRA) is a system analysis method of assessing fire risk for a nuclear power plant, which plays a more and more important role. It can provide an overall understanding of the internal fire risk for SMR. Corresponding design optimization suggestions can be obtained through further analysis of the fire areas with major fire risk, which can help reduce the risk of internal fire and improve the safety of reactor. The paper introduces the basic information of marine SMR and development of internal fire PRA. Then the internal fire risk for marine SMR have been analyzed by this method. The results show that marine SMR have high safety with a Core Damage Frequency (CDF) for internal fire risk of less than 1.0 × 10−7 per year.