[1G06-10] Fukushima Daiichi Accident

[1G07] Estimation of the In-Depth Debris Status of Fukushima Unit-2 and Unit-3 with Multi-Physics Modeling

(2)Points of discussion on debris conditions in Units 2 and 3

*IKKEN SATO¹, Akifumi Yamaji², Masahiro Furuya², Yuji Ohishi³, Xin Li¹, Hiroshi Madokoro¹, Hirofumi Fukai² (1. Japan Atomic Energy Agency, 2. Waseda Univ., 3. Osaka Univ.)

Keywords:severe accident of nuclear reactor, decommissioning of Fukushima rectors, in-depth status evaluation of the fuel debris, reactor interior observation results, degree of MCCI

As part of the combined effort to reveal in-depth fuel debris status of the damaged Fukushima Unit-2 and Unit-3 reactors, some important points of discussion concerning fuel debris conditions in Units 2 and 3 are being discussed. When we consider MCCI due to debris relocated to pedestal in Unit 3 and characteristics of debris relocated to pedestal in Unit 2, there are some elements, such as those obtained from plant internal observation, of which consistent understanding based on presently available knowledge is difficult. These discussion points are to be addressed in intermediate/long-term activities related to clarification of the accident progression behavior and the present program serves as a part of the activity to address these discussion points. This presentation gives detail of these discussion points.