Integration of direct/indirect influences of severe accidents for improvements of nuclear safety

Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo  

Integration of direct/indirect influences (hazards) of severe accidents as an index of broad risk is important for continuous improvement/optimization of nuclear safety. For that purpose, various influences of severe accidents are integrated into monetary value. The integrated influence in monetary value is called the "cost per severe accidents". The consequence analysis of severe accidents have been made of a postulated accident with source terms derived from a generic level 2 PSA. Internal and seismic events are considered as the initiating events. Sensitivity analyses are carried out to identify the dominant scenarios, dominant influences, and sensitive assumptions and parameters to the cost per accidents, per years or per kWh. Based on these findings, improvements of severe accident managements and emergency responses are recommended.