Uranium oxidation kinetics monitored by in-situ X-ray diffraction

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• 作者：S. Zalkind ; ^{shimonzl@nrcn.org.il} ; G. Rafailov ; I. Halevy ; T. Livneh ; A. Rubin ; H. Maimon ; D. Schweke
• 刊名：Journal of Nuclear Materials
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：485
• 期：Complete
• 页码：202-206
• 全文大小：1363 K
• 卷排序：485

文摘

The oxidation kinetics of U-0.1 wt%Cr at oxygen pressures of 150 Torr and the temperature range of 90–150 °C was studied by means of in-situ X-ray diffraction (XRD). A “breakaway” in the oxidation kinetics is found at ∼0.25 μm, turning from a parabolic to a linear rate law. At the initial stage of oxidation the growth plane of UO2(111) is the prominent one. As the oxide thickens, the growth rate of UO2(220) plane increases and both planes grow concurrently. The activation energies obtained for the oxide growth are Qparabolic = 17.5 kcal/mol and Qlinear = 19 kcal/mol.Enhanced oxidation around uranium carbide (UC) inclusions is clearly observed by scanning electron microscopy (SEM).