Preliminary Investigation of Pool Sloshing Behavior in a Two-Dimensional Experiment

Abstract

Studies on the pool sloshing behavior are of crucial importance for the improved assessment of energetic potential of a large whole-core-scale molten fuel pool that might be formed in the transition phase of a Core Disruptive Accident (CDA) of Sodium-cooled Fast Reactors (SFR). In this work, to clarify the mechanisms underlying this behavior, a series of simulated experiments was performed by injecting nitrogen gas into a two-dimensional rectangular water pool from a nozzle positioned at the center of pool bottom. To achieve a comprehensive understanding, various experimental parameters, including the nitrogen gas pressure, nozzle size, initial water depth, as well as the initial particle bed height, particle size, particle density and the particle shape, have been planned. From the preliminary analyses, it is found that the gas pressure, initial water depth and particle bed height are observable to have a remarkable impact on the sloshing characteristics (e.g. maximum magnitude of water level in the center and peripheries of water pool). Due to a much-reduced residence time of the injected gas in the pool, mitigation effect of gas pressure, which could restrain the intensity of sloshing motion in the fuel pool, is observable. However, as to the sloshing motion with a certain kind of particles, as the initial particle bed height increases, the intensity of sloshing motion is confirmable to become stronger and stronger. Knowledge and fundamental data from this work might be utilized for the predicative-model studies as well as verifications of SFR severe accident analysis codes in China in the future.