Thermodynamic quantities of actinides and rare earth elements in liquid bismuth and cadmium

The activity coefficients of uranium, lanthanum, cerium, praseodymium, gadolinium and yttrium in liquid bismuth were measured electrochemically as 10(-4.65), 10(-13.44), 10(-13.00), 10(-12.81), 10(-11.04), and 10(-10.17) respectively at 773K. The activity coefficients of neodymium and neptunium were estimated as 10(-12.85) and 10(-7.43) respectively from the standard potentials in LiCl-KCl eutectic molten salt and the distribution coefficients in the LiCl-KCl/bismuth system. The partial molar enthalpy of mixing and the partial molar excess entropy of solutes in both liquid bismuth and cadmium were evaluated from the change in the activity coefficients with temperature.