The final goal of MCCI prevent interaction of corium and concrete. In addition to this, we have to eliminate decay heat and secure corium coolability. But it hardly prevents MCCI phenomena. Nuclear engineer research a way which obtain coolability and delay molten corium –concrete interaction like core catcher system. MCCI accompanies many gases such as H2, CO2, CO, H2O and concrete ablation. Therefore, we focus on the how to act non condensable gases and what parameters govern concrete ablation such as temperature, decay heat, melt compositions and concrete compositions.