Refinement in the ultrasonic velocity data and estimation of the critical parameters for molten uranium dioxide

Based on the previously reported internal pressure approach and by making use of recent and more accurate experimental measurements on the density, and heat capacity of liquid UO2 up to ∼8000 K, reliable data on the sound propagation velocity in molten uranium dioxide have been obtained. An equation of state for liquid urania has also been developed which predicts a critical temperature (Tc) ≈ 10 500 K, critical pressure (Pc) ≈ 219 MPa and critical density (ρc) ≈ 2510 kg m−3.