固体相変化に伴う核分裂生成物希ガスの挙動

酸化ウランの酸化還元の挙動

抄録

The oxidation and reduction behaviors of uranium oxides were studied by the fission gas emanation method.
Three peaks were found in the heating curve of oxidation of UO₂. The temperatures and ranges where the peaks appear changed with the particle size. An X-ray diffraction method, thermal balance and O/U measurement were used to identify the existing phases. The oxidation of UO₂ occurs at the first peak. A slightly oxygen-rich phase of U₃O₈ was observed in the second peak, followed by the third peak where a slightly uranium-rich phase of U₃O₈ was observed.
The reduction of U₃O₈ to UO₂ with hydrogen occurs at about 600°C.
The mechanism of xenon release from the oxide crystals when the oxidation or reduction occurs was also studied.