Utilizing Ab Initio Molecular Dynamics to Determine Thermophysical Properties of Molten Salts

Molten salts are critical to advanced nuclear systems, playing a role as the fuel, coolant, and recycling medium. However, a significant knowledge gap exists for the fundamental properties of nuclear-relevant salts that must be narrowed in order to expedite the technical readiness level of advanced nuclear reactor concepts. Experimental efforts on molten salts are often expensive and difficult, due to the high temperatures required, as well as the volatility, corrosivity, toxicity, and radioactivity of some salts. With the rapid development and improvement of computational materials science, computational methods such as Density Functional Theory (DFT) calculations and <i>ab initio</i> Molecular Dynamics (AIMD) simulations are widely used as an effective and reliable tool to investigate the atomic interaction in materials. This work will outline recent efforts at predicting the thermophysical properties of molten salts, including the least-explored group of salts: actinide-halides. Where possible, comparison and validation with experiments are shown, and the power of computational materials science in exploring a wide swath of compositions and temperatures is demonstrated. The fundamental questions of DFT-based explorations of molten salts, such as how to describe dispersion forces, will be discussed, providing guidance on implementation. Finally, the next steps for AIMD in the world of molten salt properties will be discussed.