Atomistic Study of Radiation Damage in Ni/Inconel Multimetallic Layered Composite for Molten-Salt Reactor

Developing new radiation-resistant structural cladding materials for high temperatures and corrosive environments is one of the crucial obstacles for building Generation IV nuclear reactors. Recently, a new Ni-based Multi-metallic Layered Composite (MMLC) concept as a fuel cladding material has been proposed because of their low oxidation tendency. Our study has used the molecular dynamics (MD) approach to study the radiation-induced mixing through the heterostructure interface in five different Inconel/Ni MMLCs. We have investigated the irradiation effect on this particular MMLC by using successive collision cascades simulations up to the radiation dose of 0.5dpa. Our findings show that the thickness of the heterostructure interface and the number of defects have a linear relation with the radiation dose. Moreover, radiation-induced mixing profiles depict the higher tendency of Cr to get mixed through diffusion. The lower migration barrier of Cr has assisted the vacancy and interstitial formation process. According to the result obtained from our study, the Ni/800H (Ni₃₂Cr₂₁Fe₄₇) MMLC structure demonstrated a high radiation resistance among all five Inconel compositions that we have studied.