A modified equation of state for Xe at high pressures by molecular dynamics simulation

The exact equation of state (EOS) for the fission gas Xe is necessary for the accurate prediction of the fission gas behavior in uranium dioxide nuclear fuel. However, the comparison with the experimental data indicates that the applicable pressure ranges of existing EOS for Xe published in the literature cannot cover the overpressure of the rim fission gas bubble at the typical UO₂ fuel pellet rim structure. Based on the interatomic potential of Xe, the pressure–volume–temperature data are calculated by the molecular dynamics (MD) simulation. The results indicate that the data of MD simulation with Ross and McMahan’s potential [M. Ross and A. K. McMahan 1980 Phys. Rev. B 21 1658] are in good agreement with the experimental data. A preferable EOS for Xe is proposed based on the MD simulation. The comparison with the MD simulation data shows that the proposed EOS can be applied at pressures up to 550 MPa and 3 GPa and temperatures 900 K and 1373 K respectively. The applicable pressure range of this EOS is wider than those of the other existing EOS for Xe published in the literature.