Thermodynamic activity of uranium in ternary Cd-Gd-U alloys using molten salt electromotive force measurements

In molten salt electrorefining for spent U-Pu-Zr alloys carried out in LiCl-KCl eutectic at 500°C, plutonium and uranium along with minor actinides are co-deposited at liquid cadmium cathode. The onset potentials of typical lanthanides like Nd, La and Gd in cadmium are very close to that of uranium and plutonium and, therefore, they may also co-deposit along with uranium and plutonium if the cathodic applied potential at cadmium electrode is not precisely controlled. The present work is aimed at investigating the activity of uranium in cadmium alloys in presence of typical lanthanides, such as gadolinium using molten salt galvanic cell measurements in order to ascertain the influence of short-range ordering in liquid alloys on the thermodynamic activity of uranium