Investigation of Cell Resistance for Molten Salt Electrorefining of Spent Nuclear Fuel

Cell resistance for molten salt electrorefining of spent nuclear fuel under various electrode configurations was investigated by using the two-dimensional finite element method. Three electrorefining cell configurations were evaluated; (1) a liquid Cd anode and a solid cathode made of low carbon steel with or without a ceramic plate at the bottom, (2) a liquid Cd anode and a liquid Cd cathode, and (3) two anodes in the form of a perforated steel basket filled with spent nuclear fuel and two solid cathodes, in two different arrangements. The calculated results agreed reasonably well with previously obtained experimental data. The effect of polarization on the cell resistance was found to be small for a typical uranium concentration in the molten salt electrolyte and the liquid Cd anode. The calculation results are helpful in interpreting experimental data, and a correlation formula was developed that may be useful in estimating the cell resistance of new cell designs.