Electrochemistry of selected lanthanides in FLiBe and possibilities of their recovery on reactive electrode

摘要

Among other applications, electrochemical based separation of actinides and lanthanides from molten salt media seems to be suitable method for reprocessing of spent nuclear fuel in proposed future types of nuclear reactors such as Molten Salt Reactor. One of the most interesting features of the MSR concept is a circulation of liquid molten fluoride fuel mixture. It allows the fuel to be continuously ("on-line") reprocessed as it is necessary for continuous reactor operation. The pyrochemical separation processes seem suitable for the "on-line" reprocessing technology and electrochemical separations are one of the most promising methods for separation of fissile material and fission products. This work is focused on electrochemical behaviour of several lanthanides (Sm, Gd) in FLiBe on inert (Mo, Mo) and reactive (Ni) electrodes. Electrochemical behaviour was studied by cyclic voltammetry and in the case of gadolinium, electrolytic product was analysed by SEM-EDX analysis. Specific interactions between rare earth elements and polymer-like structure of Be-based melt were taken into account and experimental results are interpreted. Evaluation of possibilities of lanthanides recovery on reactive electrode (Ni) is presented.