TY - GEN
T1 - Preliminary evaluation on the relocation phase of ex-vessel debris of fukushima daiichi nuclear power plant unit-3
AU - Li, Xin
AU - Yamaji, Akifumi
AU - Furuya, Masahiro
AU - Sato, Ikken
AU - Madokoro, Hiroshi
AU - Ohishi, Yuji
N1 - Funding Information:
The authors greatly appreciate the advice and help from Dr. Guangtao Duan in the University of Tokyo in developing the improved MPS method. A part of this study is the result of Nuclear Energy Science & Technology and Human Resource Development Project of Japan. A part of this study is the result of “Understanding Mechanisms of Severe Accidents and Improving Safety of Nuclear Reactors by Computer Science” of Waseda Research Institute for Science and Engineering and the authors acknowledge support of the Institute for Advanced Theoretical and Experimental Physics, Waseda University.
Publisher Copyright:
© 2021 by ASME.
PY - 2021
Y1 - 2021
N2 - To deepen our understanding for the current debris status and investigate the debris-structure interactions in the pedestal region of Fukushima Unit-3, the Moving Particle Semi-implicit (MPS) method is further developed for simulation of multicomponent liquid/solid relocation with solid-liquid phase changes aiming for plant-scale practices. The improvement of the existing MPS method mainly consists of two parts, namely 1) the improvement of numerical stability and accuracy, including a) applying second-order corrective matrix to the particle interaction models and b) particle shifting that can optimize particle configurations; and 2) improvement of calculation efficiency, including a) hybrid OpenMP and MPI parallelization and b) particle type-dependent speed-up algorithms to reduce calculation costs for particles with extremely high viscosity and low velocity. In the current study, the improved MPS method is validated against the experiments carried out at Waseda University, in which molten salt droplets were released to interact with aluminum pillars and solidify on them. Good agreement of the total height of the solidified salt and its distribution on the pillars has been achieved. The successful validation has shown the capability of the current MPS method for simulations of Unit-3 pedestal region.
AB - To deepen our understanding for the current debris status and investigate the debris-structure interactions in the pedestal region of Fukushima Unit-3, the Moving Particle Semi-implicit (MPS) method is further developed for simulation of multicomponent liquid/solid relocation with solid-liquid phase changes aiming for plant-scale practices. The improvement of the existing MPS method mainly consists of two parts, namely 1) the improvement of numerical stability and accuracy, including a) applying second-order corrective matrix to the particle interaction models and b) particle shifting that can optimize particle configurations; and 2) improvement of calculation efficiency, including a) hybrid OpenMP and MPI parallelization and b) particle type-dependent speed-up algorithms to reduce calculation costs for particles with extremely high viscosity and low velocity. In the current study, the improved MPS method is validated against the experiments carried out at Waseda University, in which molten salt droplets were released to interact with aluminum pillars and solidify on them. Good agreement of the total height of the solidified salt and its distribution on the pillars has been achieved. The successful validation has shown the capability of the current MPS method for simulations of Unit-3 pedestal region.
KW - Decommissioning
KW - Fukushima Daiichi Nuclear Power Plant
KW - MPS method
KW - Severe accident
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U2 - 10.1115/ICONE28-64540
DO - 10.1115/ICONE28-64540
M3 - Conference contribution
AN - SCOPUS:85117759166
SN - 9784888982566
T3 - International Conference on Nuclear Engineering, Proceedings, ICONE
BT - Computational Fluid Dynamics (CFD); Verification and Validation; Advanced Methods of Manufacturing (AMM) for Nuclear Reactors and Components; Decontamination, Decommissioning, and Radioactive Waste Management; Beyond Design Basis and Nuclear Safety; Risk Informed Management and Regulation
PB - American Society of Mechanical Engineers (ASME)
T2 - 2021 28th International Conference on Nuclear Engineering, ICONE 2021
Y2 - 4 August 2021 through 6 August 2021
ER -