[1D01-07] PRA Method 1

[1D03] Risk assessment of hydrogen venting scenarios considering the emergency action level transmission timing

*Nobuhito Shiomura¹, Fumie Sebe¹, Nobuhisa Takezawa¹, Hideki Horie¹, Kaoru Matsushita¹, Mika Tahara¹ (1. TOSHIBA ESS)

Keywords:Level 3 PRA, Risk assessment, Evacuation Planning, Hydrogen venting, WinMACCS

On the quantitative risk assessment of nuclear power accident, it is important to integrate on-site and off-site information. In this study, risk assessment was performed for the following three accident scenarios: “a. Containment venting scenario to control the containment overpressurization due to low hydrogen leakage from the containment vessel”, “b. Hydrogen venting scenario to control the hydrogen concentration build-up in the reactor building”, and “c. Hydrogen venting failure scenario”. Wherein residents are classified into three categories with their residential area and evacuation behavior. As the result of the evaluation, health effect risk between different protective actions and scenarios were obtained and could be compared. Therefore, risk reduction measures are applied for high-risk residents and their effectiveness was confirmed.