Volatilization of urania under strongly oxidizing conditions

Vapor pressures are presented for UO3(g) over U3O8−x in air by the transpiration technique. Measurements are also presented for UO3 over the two-phase region, UO2.24-UO2.60. Measurements made in steam-oxygen led to establishment of the homogeneous equilibrium UO3(g) + H2O(g) = UO2(OH)2(g). Some thermochemical values are presented. A method is shown for computing UO3 and UO2(OH)2 pressure for any temperature, steam concentration, and oxygen potential. Total volatilities and mass loss rates have been computed for some potential loss of pool coolant scenarios.