Application of Binary Ga–Al Alloy Cathode in U Separation from Ce: The Possibility in Pyroprocessing of Spent Nuclear Fuel

• Published in: Electrochimica acta 2020-09, Vol.353, p.136449, Article 136449
• Main Authors: Yang, Da-Wei, Liu, Ya-Lan, Yin, Tai-Qi, Jiang, Shi-Lin, Zhong, Yu-Ke, Wang, Lin, Li, Mei, Chai, Zhi-Fang, Shi, Wei-Qun
• Format: Article
• Language: English
• Subjects: Binary alloys; Cathodes; Crystal structure; Electrodes; Electrolysis; Gallium base alloys; Ga–Al alloy Electrode; Heat treating; Inductively coupled plasma; LiCl–KCl eutectic; Lithium chloride; Optical emission spectroscopy; Pyroprocessing; Separation; Spent nuclear fuels; U (III)
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.136449

To study the application perspectives of binary Ga–Al alloy electrodes in pyroprocessing, the utilization of Ga–Al alloy electrode for the separation of U from Ce was studied in this work. Specifically, the reduction behaviors of U (III) on Ga, Al and Ga–Al alloy electrodes was first explored in LiCl–KCl eutectic at 773 K. The cathode peak potential of U (III) at the Ga–Al alloy electrode was 0.44 V (vs. Li/Li3Bi), and less affected by the Ga/Al ratio. Moreover, potentiostatic electrolysis at 0.55 V (vs. Li/Li3Bi) was conducted on the Ga–Al alloy electrode for 4 h to separate U from Ce. X-ray diffraction (XRD) analysis indicated the co-existence of Al3U and Ga3U with an identical crystal structure in the deposits. Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) illustrated a good diffusion of U metal in Ga–Al alloy electrodes. Inductive coupled plasma optical emission spectrometry (ICP-OES) determinations exhibited an excellent separation performance of the Ga–Al alloy electrode.