[1O13-14] Estimation of Fukushima Daiichi Accident

[1O14] Estimation of accident progression scenarios up to before and after hydrogen explosion at Fukushima Daiichi NPP Unit-3

*Kenichiro Nozaki¹, Penghui Chai¹, Shoichi Suehiro¹, Takeshi Honda², Masato Mizokami², Kenji Owada², Shinya Mizokami² (1. TEPSYS, 2. TEPCO HD)

Keywords:Fukushima Daiichi Nuclear Power Plant, Unit-3, hydrogen explosion, accident progression

Accident progression scenarios of Fukushima Daiichi NPP Unit-3 up to before and after hydrogen explosion were estimated based on the plant parameters and the results of previous studies such as estimation of the amount of leaked gas consistent with the video footage at the time of the explosion. As a result, it was estimated that the progression of MCCI may have been limited due to the cooling of the fuel debris on the pedestal floor by the water in the D/W, and that the main cause of the pressure drop before and after the explosion may have been the decrease in the amount of water vapor generated due to the depletion of water in the D/W.