In this study, a numerical approach for analyzing the internal status of Molten CoreConcrete Interaction (MCCI) has been developed based on Moving Particle Semi-implicit (MPS) method. Among the key required models, such as accurate viscosity interaction model for solidifying particles and interface tension models of different liquid phases, preliminary attempts have been made with new models. Namely, a simple mixing model and gas hosting particle model has been implemented to simulate the experiment with affordable calculation cost. The analysis results for VULCANO VF-U1 experiment have shown the possible mechanisms responsible for the characteristic distribution of the solidified metallic corium, which seemed to be highly dependent on the density of surrounding oxidic coriu
