A preliminary probabilistic safety assessment for ITER

International Thermonuclear Experimental Reactor (ITER), the world' largest fusion facility, has officially began assembly work at July 28, 2020 and plan to operation at December 2025. If ITER can operate successfully, which means the people step forward on the road to peaceful use of fusion energy. Meanwhile, how safe about ITER and whether the ITER will cause radiation harm to the surrounding environment and personnel is our concern. A lot of safety assessment work had been done for ITER using a deterministic approach through conservative assumptions and calculations. But it's not enough. This paper aims to estimate the radiological risk of ITER. The first, the probabilistic safety assessment (PSA) progress for ITER was proposed in this paper and then, the preliminary PSA was applied on ITER and the results shows that ITER has a high frequency of accidents in the range of small dose. But the large-scale radiological consequences are unlikely. The reasons for those results are also analyzed in this paper. Those result could provide some valuable reference for risk assessment and safety supervision of fusion commercial reactor in the near future.