Electrochemical and Spectroscopic Monitoring of Interactions of Oxide Ion with U (III) and Ln (III) (Ln = Nd, Ce, and La) in LiCl-KCl Melts. Issue 8 (1st January 2017)

• Record Type: Journal Article
• Authors: Choi, Suhee; Bae, Sang-Eun; Park, Tae-Hong
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 8(2017)
• Page Start: H5068
• Page End: H5073
• Publication Date: 2017-01-01
• Subjects: Lanthanide -- LiCl-KCl -- Lithium Oxide -- Molten salt -- Pyroprocess -- Uranium; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0071708jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Using cyclic voltammetry and UV-vis absorption spectroscopic methods, we studied the precipitation reactions of trivalent uranium and lanthanides (Nd, Ce, and La) with the oxide ion in LiCl-KCl molten salts, which are likely side reactions during the electrorefining process for nuclear fuel treatment. The in situ electrochemical and spectroscopic monitoring demonstrated that U 3+ consumed O 2− with the mole ratio of 2:1, whereas the lanthanide ions reacted with O 2− with the mole ratio of 1:1. Raman spectroscopy and X-ray diffraction were also employed to analyze the precipitates, confirming that U 3+ was precipitated and oxidized into UO2, while the trivalent lanthanide ions formed oxychlorides (LnOCl). As a preliminary study of actinide co-precipitation, we also electrochemically monitored the precipitation reactions in a mixed melt containing uranium and lanthanides, demonstrating a higher reactivity of the former with the oxide ion in LiCl-KCl.