Critical assessment of equation of state data for UO2

Abstract A new equation of state for UO 2 has been derived using the theory of significant liquid structures, which predicts a critical temperature of 7560K, a critical pressure of 1210 atm, and a critical density of 1.66 g/cm 3 . The resulting critical compressibility of 0.316 is in good agreement with the values predicted by the theory of corresponding states. Consistency between literature data on enthalpy of solid UO 2 , recent vapour pressure measurements over liquid UO 2 , and the pressure data over solid UO 2 could only be obtained by the inclusion of an electronic excitation term in the gaseous partition function. A new set of free energy functions for gaseous and solid UO 2 is presented.