Vapor Pressure Determination of Liquid UO₂ Using a Boiling Point Technique

By analogy with the classic boiling point method, a quasi-stationary millisecond laser-heating technique was applied to measure the saturated vapor pressure curve of liquid UO₂ in the temperature range of 3500 to 4500 K. The results are represented by log p (MPa) = 5.049 - 23 042/T (K), which gives an average heat of vaporization of 441 kJ/mol and a normal boiling point of 3808 K. In addition, spectral emissivities of liquid UO₂ were determined as a function of the temperature at the pyrometer wavelengths of 752 and 1064 nm.