[2H01-02] Analysis Method Development 1

[2H01] Development of Criticality Evaluation Method of Fuel Debris Bed Formation Process by Falling in Water

Modeling of Granular Fuel Debris Shape by Parameter Calibration of Particle Method Applying Optimization Method

*Takeshi Muramoto¹, Jun Nishiyama¹, Toru Obara¹ (1. Tokyo Tech)

Keywords:Fuel debris, Criticality safety, Solid-liquid two phase flow, Particle method, Bayesian optimization

Criticality evaluation considering behavior of fuel debris in water during sedimentation process is important for ensuring safety work of retrieval of fuel debris. The individual fuel debris are considered to have various sizes and shapes. In this study, the individual fuel debris was modeled as a sphere. Then the sliding friction and rolling friction of the sphere were determined appropriately and efficiently by an optimization method in order to calculate shape effect of fuel debris in simulation of fuel debris falling in water. Finally, the validation of the calculation model was performed by comparison between the experiment and simulation.