Behavior of a Corium Jet in High Pressure Melt Ejection from a Reactor Pressure Vessel,

摘要

The report provides results from analytical and experimental investigations on the behavior of gas supersaturated molten jet expelled from a pressurized vessel. Models are developed for jet expansion, primary breakup of the jet, and secondary fragmentation of melt droplets. The jet expansion model is based on a general relation for bubble growth which includes both inertial-controlled and diffusion-controlled growth phase. The model is able to predict the jet void fraction, jet radius as a function of axial distance from the pressure vessel bubble size, and bubble pressure. Predicted fragment sizes are in reasonably good agreement with the data. Parametric calculations for a TMLB' accident show that the corium jet is disrupted within a few initial jet diameters from the vessel. The radius of the corium jet at the level of the reactor cavity floor is predicted to be in the range 0.8m - 2.6m.