Abstract: The massive non-condensable gases from molten core-concrete interaction (MCCI) cause the containment pressure acceleration, which would threaten the containment integrity. In order to improve the simulation of MCCI progress, the models of water ingress and melt eruption were added into the current released MELCOR version 2.2. In this paper, the cavity geometer of large power passive PWR was modeled, and the application of water ingress and melt eruption added currently was analyzed. The analysis results show that during MCCI progress, the active of the water ingress and melt eruption models influences the crust layer formed on the face between the melt debris and the water pool. The repeated formation and decomposation of crust layer accelerate the vaporization of the water, and decrease the ablation rate of the concrete. After the formation of the crust layer on the top and side of the melt debris, the downward transferred heat is enhanced, thus this trend increases the concrete ablation rate. The currently added models have the capability to simulate the MCCI in detail, therefore, it provides reliable technical security for severe accident safety review with PWR NPP.