The potential of pyroprocessing for partitioning Purex wastes

The authors are investigating the feasibility of separating actinide elements from gross amounts of fission products by pyrochemical techniques. In the present experimental effort they measured the distribution coefficients in two candidate molten salt-molten alloy systems for a mixture of isotopes representing the radioactive products present in aged LWR wastes. The salt phase in both cases is a mixture of MgCl2, NaCl, and KCl in a mole ratio of 50:30:20, respectively. The metal phases studied are Mg containing 0, 30, 50, and 70 weight % Cu, and Mg containing 0, 30, 50, and 70 weight % Zn. The data obtained show that the fission products fall into three distinct groups: those which distribute almost completely to the salt phase, those which distribute almost completely to the metal phase, and a small group which distributes about equally between the salt and metal phases. The results indicate the feasibility of partitioning actinides from typical reactor wastes in compact radiation-resistant systems