Numerical study on sedimentation behavior of solid particles used as simulant fuel debris

This paper presents numerical simulations using the discrete element method (DEM) to model sedimentation behavior of solid debris particles, which is significant for estimates of the coolability of debris beds. A series of experiments of gravity driven discharge of solid particles into a quiescent water pool was used to validate the DEM simulation method. We evaluated the effects of three crucial factors: particle density, particle diameter, and nozzle diameter on three key quantitative parameters: particle dispersion angle, particle fall time in the pool, and the height of the deposited particle bed to express the particle sedimentation behavior. The three crucial factors play a significant role in the particle sedimentation behavior. We compared the experimental and simulated results of the particle dispersion angle and particle fall time in the pool, and the height and shape of the deposited particle bed. The general trend of the simulation results indicates a reasonable agreement with the experimental observations. The simulations exhibit the potential applicability of the DEM-based simulation technique for the prediction of particle sedimentation behavior.