Given the nuclear reactor severe accident, molten uranium may relocate and contact with iron based structural material which could result in melting of iron based material. According to binary phase diagram, contact between Fe and U may include eutectic phenomenon where melting temperature of the material drop sharply. Information of melting penetration rate of iron based material by uranium is important for melting relocation investigation during severe accident. MPS_LER has been developed and validated to simulate eutectic phenomena of Fe-U system. In the present study, the MPS_LER was used to predict melting penetration of Armco Iron by liquid uranium that has not been experimentally recorded. The present results show MPS_LER's prediction on melting penetration rate of Fe-U system at high temperature.