Electrochemistry of uranium in LiF–BeF2 melt.

A study of the electrochemistry of uranium in LiF–BeF2 system important for molten salt reactor concept was conducted at W and Ni electrodes. Cyclic voltammetry and chronopotentiometry methods were used. Two-step reduction mechanism for U4+ ions involving one electron exchange in soluble/soluble U4+/U3+ system and three electron exchange in the second step were found on W electrode. Both processes were identified as reversible and diffusion-controlled. Based on voltammetric and chronopotentiometric measurements, the diffusion coefficient of U4+ ions at 813 K was calculated: D(U4+) = 1.26 × 10−6 cm2 s−1 and D(U4+) = 1.28 × 10−6 cm2 s−1, respectively. Formation of U–Ni alloys was observed on Ni electrode. [ABSTRACT FROM AUTHOR]