Numerical simulation of debris bed formation in severe accident

This paper presents 2-D numerical simulations using the modified discrete element method (DEM) on debris bed formation. The modified DEM facilitates the application by reorganizing the calculation parameters. A series of experiments performed by gravity driven discharge of solid particles into a quiescent water pool was used to validate the present simulation method. We made comparison of the particle dispersion angle and particle fall time in the pool, and the shape of particle bed between the experimental and simulation results. In this comparison, the general trend of simulation results indicates a reasonable agreement with the experimental observations.