Sensitivity Analysis for Propagation Phase in Steam Explosion under Submerged Reactor

One of those is a molten fuel-coolant interaction (FCI). An explosion can be caused by violent boiling when water is quickly heated by the corium during the FCI. For the steam explosion issue, it has to be proven that the integrity of containment is protected. If it cannot meet the criteria of the safety margin, a system or procedure, which minimize the risk of the steam explosion, has to be equipped additionally. The steam explosion consists of four phases, which are premixing, triggering, propagation, and expansion. In this paper, the results of a premixing experiment, which was performed at the experimental facility of TROI (Test for Real cOrium Interaction with water) in Korea, were utilized for analyzing the effects of the parameters on the load of the explosion. The purpose of this paper is to analyze the effect of the parameters in the propagation phase on the impact load of a steam explosion. The parameters in the fragmentation rate during the propagation phase were analyzed for estimating the changes of the effects on the steam explosion. The initial size of the melt jet affects several variables in the simulations. Some sensitive parameters for sub-phenomena in the steam explosion have to be carefully set for more exact simulations. Accordingly, the risk of the steam explosion depending on the end state of the premixing phase has to be specified based on the results of more parametric analysis.