[1A01-06] Fukushima Daiichi NPS Accident

[1A01] Estimation of the In-Depth Debris Status of Fukushima Unit-2 and Unit-3 with Multi-Physics Modeling

(6)Overview and Preliminary Criticality Evaluation of the Unit-3 Pedestal Debris

*Akifumi Yamaji¹, Kazuma Kishimoto¹, Xin Li¹, Masahiro Furuya¹, Ikken Sato³, Hiroshi Madokoro³, Yuji Ohishi² (1. Waseda Univ., 2. Osaka Univ., 3. JAEA)

Keywords:severe accident of a nuclear reactor, decommissioning of Fukushima reactors, MPS method, criticality evaluation, levitation method

In-depth pedestal debris status of the Fukushima Unit-2 and Unit-3 are being investigated through multi-physics modeling of thermal-hydraulics (particle method, and simulant experiment), criticality evaluation and high temperature melt property evaluations (levitaion technique). This presentation gives test evaluation of criticality of Unit-3 pedestal debris, based on debris distributions to be presented in series Number (7). The Fe-B heat capacity measurements will also be reported in presentation number (8).