Introduction of external cost regarding severe accident as an index of nuclear power plant risk and its relationship with sourceterm

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

In this research, the authors introduce the "external cost regarding severe accident" as an index to evaluate the effect of severe accident in a nuclear power plant. This can contribute to an improvement in nuclear power plant risk evaluation which needs not only probability evaluations but also effect evaluations. To calculate the external cost regarding severe accident, typical sequences of severe accidents are picked up first. Containment failure frequency (CFF) and sourceterms of each sequence are taken from the results of level 2 PSA. The sourceterm of each sequence is input into the level 3 PSA code OSCAAR which was developed by Japan Atomic Energy Agency (JAEA). Using these outputs, the external cost regarding severe accident is calculated. The results were compared with the amount of sourceterms of each severe accident which can be one of the indexes to evaluate the effects of severe accident.