Abstract
Eutectic melting between metallic fuel and steel cladding and/or steel structures is one of dominant phenomena for the progress of core disruptive accidents (CDAs) of SFRs. In this study the atomic diffusion at the interface between Pu and Fe was investigated by using classical molecular dynamics (CMD). The simulation was performed using Modified Embedded Atom Method (MEAM) (Baskes, 1992). For plutonium the potential model developed by Baskes (2000) was used and for iron that by Lee et al.(2001) was applied. The interactions between plutonium and iron atoms were calculated by using the potential model determined so as to reproduce the material properties of PuFe_2. The simulation was made with a system in which a semi-infinite, two-dimensional plate of iron with a thickness of 2.5 nm was in contact with solid or liquid plutonium with almost same thickness as the iron plate. The diffusion of atoms across the interface was observed for all the temperature conditions in the present study (900K〜1850K). The diffusion rate was increased exponentially with temperature. The diffusion rate depended on the plane direction of the surface of the iron plate as well as the temperature.
