Yaakov Idell¹, Mark Wall¹, Wigbert Siekhaus¹, Kerri Blobaum¹, William McLean¹; ¹Lawrence Livermore National Laboratory

Material degradation of uranium resulting from the uranium-oxygen reaction has long been of great interest to the nuclear industry, but the early stage oxidation kinetics is not well understood. Previous investigations have employed characterization techniques that include microbalance, x-ray diffraction, and spectroscopic ellipsometry in order to understand the oxide growth behavior; however, these studies have been primarily focused on thick oxide films (>1 µm). Additionally, none of these techniques provide spatial information of the oxide growth. We developed an automated and rapid surface sensitive data collection technique that provides three-dimensional spatial data of the growing oxide layer with sub-nanometer thickness resolution using white-light interferometry. Early stage oxidation kinetics and film cracking behavior of uranium heated to 90 °C under 500 torr of pure O2 will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.