Helium solubility in uranium dioxide from molecular dynamics simulations

Pathways to prediction of phase equilibria in He–U–O system at high temperatures based on the single- and two-box molecular dynamics (MD) technique are discussed. Single-box MD simulation of He gas bubble in uranium dioxide has been carried out, helium gas infusion processes studied and its limited efficiency illustrated. More efficient two-box MD simulation technique was applied to study of helium dissolution in stoichiometric UO2 and non-stoichiometric UO2±x single-crystals. Equilibrium solubility of helium in UO2 and UO2±x estimated and compared with experimental data. The deviations from Henry’s law at high pressures of helium are discussed.