Construction of a Rotating Disk Electrode System for Measuring Electrochemical Parameters of a Metal Ion in LiCl–KCl Melt: Electrochemical Properties of Sm³⁺

Chan-Yong Jung^1,a, Hwakyeung Jeong^1,a, Na-Ri Lee¹, Jong-Yun Kim^1,2, Tae-Hong Park^1,2, Sang-Eun Bae^1,2,*

¹Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea
²University of Science and Technology, 217, Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea

Received 2024-04-17 ; Revised 2024-05-07 ; Approved 2024-05-22

Abstract

Pyrochemical processing and molten-salt reactors have recently garnered significant attention as they are promising options for future nuclear technologies, such as those for recycling spent nuclear fuels and the next generation of nuclear reactors. Both of these technologies require the use of high-temperature molten salt. To implement these technologies, one must understand the electrochemical behavior of fission products in molten salts, lanthanides, and actinides. In this study, a rotating-disk-electrode (RDE) measurement system for high-temperature molten salts is con structed and tested by investigating the electrochemical reactions of Sm3+ in LiCl–KCl melts. The results show that the reduction of Sm3+ presents the Levich behavior in LiCl–KCl melts. Using the RDE system, not only is the diffusion-layer thickness of Sm3+ measured in high-temperature molten salts but also various electrochemical parameters for Sm3+ in LiCl–KCl melts, including the diffusion coefficient, Tafel slope, and exchange current density, are determined.

Key Words : Pyrochemical processing, LiCl-KCl, Rotating disk electrode, Samarium, Tafel slop, Exchange current density