Risk assessment of a sodium-cooled fast reactor for abnormal snowfall with considering global warming

Koike, Akari*; Nakashima, Risako*; Sakai, Takaaki*; Doda, Norihiro  ; Tanaka, Masaaki  

A dynamic PRA using the Continuous Markov chain Monte Carlo (CMMC) method was performed for a sodium-cooled fast reactor to evaluate abnormal snowfall events in which the snowfall amount tends to increase due to global warming. In the analysis, the probability of exceeding the core outlet temperature limit after 24 hours was evaluated. The loss of functions of the emergency diesel generator and the air cooler due to snowfall and the recovery of the functions by the operator's snow removal as an accident management measure were considered. The results show that snow removal as an accident management measure is not effective under abnormal snowfall conditions with considering global warming.