| Abstract Scope |
The development and deployment of molten salt reactors requires a detailed understanding of how local chemistry governs long-term material compatibility and performance. One of the key challenges for improving molten salt usability in reactors is predicting the influence of impurities on the salt structure and linking this to salt behavior. In this work, we investigate eutectic molten FLiBe with silicon, carbon, chromium, and nickel impurities using ab initio simulations. We compute the pair distribution functions, ion diffusivities, and (BeF4)2- tetrahedra clustering behavior, with a focus on how impurity-induced changes affect free-fluorine concentrations and salt fluoroacidity. These structural trends are supported by Bader charge analysis and early-stage thermodynamic assessments. Furthermore, we evaluate the influence of these changes on salt corrosivity. Our results highlight how impurity-driven changes in local bonding environments could impact the corrosivity of FLiBe, informing impurity management strategies for reactor applications. |