Electrochemical and Thermodynamic Properties of UCl3 in LiCl-KCl Eutectic Salt System and LiCl-KCl-GdCl3 System. Issue 9 (30th June 2017)

• Record Type: Journal Article
• Authors: Yoon, Dalsung; Phongikaroon, Supathorn
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 9(2017)
• Page Start: E217
• Page End: E225
• Publication Date: 2017-06-30
• Subjects: GdCl3 -- LiCl-KCl -- Pyroprocessing -- UCl3; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0411709jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The electrochemical techniques including cyclic voltammetry (CV), open circuit potential (OCP), and electrochemical impedance spectroscopy (EIS) were performed to understand fundamental behaviors of UCl3 in LiCl-KCl salt at concentrations ranging from 0.5 wt% to 4 wt% and temperatures from 723 K to 798 K. In addition, the same measurements were performed in LiCl-KCl-UCl3 -GdCl3 for evaluating the effects of GdCl3 co-existence on uranium properties. Diffusion coefficients (D) of UCl3 was calculated by measuring reduction peaks of U 3+ /U in CV experiments. The values of D were linearly correlated with temperature, but weakly affected by concentration under 4 wt% of UCl3 . The addition of GdCl3 showed no significant changes in D values. The equilibrium potentials (E) of U 3+ /U couple were measured from OCP data and no significant influence of GdCl3 was observed on the E trend. From the measured E values, the apparent standard potentials and thermodynamic properties of U 3+ /U were calculated and reported in this study. Lastly, EIS measurements were performed to explore the exchange current densities (i0 ) of U 3+ /U, showing linear relationships with both temperature and concentration, which were expressed using a simple linear correlation. Values of i0 followed the same linear expression regardless of GdCl3 presence in the system.