Son Jiyoung, Riechers Shawn L, Yu Xiao-Ying
Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
Oak Ridge National Laboratory, Materials Science and Technology Division, Oak Ridge, TN 37830, USA.
Micromachines (Basel). 2023 Sep 1;14(9):1727. doi: 10.3390/mi14091727.
Understanding the corrosion of spent nuclear fuel is important for the development of long-term storage solutions. However, the risk of radiation contamination presents challenges for experimental analysis. Adapted from the system for analysis at the liquid-vacuum interface (SALVI), we developed a miniaturized uranium oxide (UO)-attached working electrode (WE) to reduce contamination risk. To protect UO particles in a miniatured electrochemical cell, a thin layer of Nafion was formed on the surface. Atomic force microscopy (AFM) shows a dense layer of UO particles and indicates their participation in electrochemical reactions. Particles remain intact on the electrode surface with slight redistribution. X-ray photoelectron spectroscopy (XPS) reveals a difference in the distribution of U(IV), U(V), and U(VI) between pristine and corroded UO electrodes. The presence of U(V)/U(VI) on the corroded electrode surface demonstrates that electrochemically driven UO oxidation can be studied using these cells. Our observations of U(V) in the micro-electrode due to the selective semi-permeability of Nafion suggest that interfacial water plays a key role, potentially simulating a water-lean scenario in fuel storage conditions. This novel approach offers analytical reproducibility, design flexibility, a small footprint, and a low irradiation dose, while separating the α-effect. This approach provides a valuable microscale electrochemical platform for spent fuel corrosion studies with minimal radiological materials and the potential for diverse configurations.
了解乏核燃料的腐蚀对于长期储存解决方案的开发至关重要。然而，辐射污染风险给实验分析带来了挑战。我们改编了液 - 真空界面分析系统（SALVI），开发了一种小型化的附着氧化铀（UO）的工作电极（WE），以降低污染风险。为了在微型电化学池中保护UO颗粒，在其表面形成了一层薄薄的Nafion。原子力显微镜（AFM）显示出一层致密的UO颗粒层，并表明它们参与了电化学反应。颗粒在电极表面保持完整，只是有轻微的重新分布。X射线光电子能谱（XPS）揭示了原始UO电极和腐蚀后的UO电极之间U（IV）、U（V）和U（VI）分布的差异。腐蚀电极表面上U（V）/U（VI）的存在表明，可以使用这些电池研究电化学驱动的UO氧化。我们由于Nafion的选择性半透性而在微电极中观察到U（V），这表明界面水起着关键作用，可能模拟了燃料储存条件下贫水的情况。这种新方法具有分析可重复性、设计灵活性、占地面积小、辐射剂量低等优点，同时分离了α效应。这种方法为乏燃料腐蚀研究提供了一个有价值的微观电化学平台，所需放射性材料最少，并且具有多种配置的潜力。
