Electrorefining of U-Pu-Zr alloy on solid Al electrodes in LiCl-KCl eutectic melt initially containing Zr ions

Abstract

Electrorefining process in molten chloride salts using solid aluminium cathodes to recover actinides (An) is developed in ITU. Complete recovery of actinides in electrorefining of An-Zr alloy fuels can not be achieved without co-dissolution of Zr. It has been shown in previous experiments that the presence of Zr ions resulted in a significant deterioration in quality of the deposit. The present work has been focussed on a better understanding of the electrochemical behaviour of Zr ions in LiCl-KCl melt. In addition, electrorefining of UPuZr alloy in a melt containing dissolved Zr at the beginning of the process has been carried out. At first, Zr4+ content was chemically reduced by addition of UPuZr alloy forming a dispersion of Zr-containing particles in the melt. Electrorefining process in this modified melt yielded compact deposits consisting of UAl3, UAl4, PuAl3 and PuAl4 alloys.