[1E01-07] Severe Accident 1

[1E04] Estimation of the In-Depth Debris Status of FukushimaUnit-2 and Unit-3 with Multi-Physics Modeling

(14)MPS Analyses of Debris-pedestal Structure Interactions of Unit-3

*Xin Li¹, Takanari Fukuda¹, Akifumi Yamaji¹, Ikken Sato², Masahiro Furuya¹, Yuji Ohishi³ (1. Waseda Univ., 2. JAEA, 3. Osaka Univ.)

Keywords:severe accident , decommissioning of Fukushima reactors , numerical simulation, MPS method

Decommissioning of Fukushima Daiichi (1F) Nuclear Power Plants requires knowledge of the in-depth debris status within the pedestals of damaged 1F reactors. As part of the Nuclear Energy Science&Technology and Human Resource Development Project (2019-2021), the Moving Particle Semi-implicit (MPS) method is developed for modeling multi-component liquid/solid relocation with solid-liquid phase changes. With developed MPS method, debris relocation/interaction with pedestal structures (i.e., mid-level work platform etc.) in 1F Unit-3 over 75-minute relocation phase (estimated from plant data) were simulated in a 1/10-scaled geometry (previously reported at the AESJ Annual Meeting, September 2021). In this study, we will report the debris-structure thermal status during re-heating period (i.e., March 16^th-19^th, 2011) with different representative debris distribution obtained in the previous study.