KINETICS AND MECHANISM OF THE OXIDATION OF URANIUM DIOXIDE AND URANIUM DIOXIDE PLUS FISSIA SINTERED PELLETS

摘要

Oxidation of uranium dioxide sintered pellets with oxygen, in the pressure range of 3 to 800 mm Hg, a temperature range of 0 to 450 °C, and with a 0 to 5% concentration of fission product oxides (fissia), has been studied, in an effort to elucidate the kinetics and mechanism of the reactions involved. A mechanism is postulated for processes which control the oxidation from UO2 to U308, in terms of the following reactions:chemisorption of oxygen on the UO2 surface, followed by adsorption of oxygen on the chemisorbed layer where p is oxygen pressure in mm Hg.