In order to investigate the impact of fission products on the oxidation of spent fuel in the cladding separation process, the oxidation behavior and kinetic mechanism of UO and impact of M (M = Ce, Sn, Sr, Se) oxides on the oxidation of UO to UO were investigated by TG/DSC, XRD, FT-IR and Raman. It was found that the oxidation of UO to UO went through two stages: UO→UO; UO→UO. Doping M oxide in UO could not change the two-step mechanism, and significantly inhibited the formation of UO. The final products of CeO and SrO-doped UO oxidation contained 20% UO and 47% UO, respectively. The doping of M oxide increased the onset oxidation temperature of the two oxidation stages of UO by 5–65 °C. In addition, the kinetic mechanism of UO oxidation was investigated and found that the first and second oxidation stages were controlled by 1st order reaction or nucleation and growth, and 2nd order reaction, respectively. The doping of M oxide significantly affected the kinetic mechanism of the first stage.

中文翻译：

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裂变产物（Ce、Sn、Sr、Se）氧化物对 UO2 氧化为 U3O8 的影响

为了研究包壳分离过程中裂变产物对乏燃料氧化的影响，研究了UO的氧化行为和动力学机理以及M（M=Ce、Sn、Sr、Se）氧化物对UO氧化的影响通过 TG/DSC、XRD、FT-IR 和拉曼研究了 UO 的变化。研究发现UO氧化成UO经历了两个阶段：UO→UO； UO→UO。在UO中掺杂M氧化物并不能改变两步反应机理，并且显着抑制了UO的形成。 CeO和SrO掺杂UO氧化的最终产物分别含有20% UO和47% UO。 M氧化物的掺杂使UO的两个氧化阶段的起始氧化温度提高了5-65℃。此外，研究了UO氧化的动力学机理，发现第一和第二氧化阶段分别由一级反应或成核和生长以及二级反应控制。 M氧化物的掺杂显着影响第一阶段的动力学机制。