On Metal Aggregates in Spent Fuel, Synthesis and Leaching of Mo-Ru-Pd-Rh Alloy

The results of leaching tests on the synthesised 46%Mo-29%Ru-21%Pd-4%Rh alloy show selective release Mo at both reducing and air saturated conditions. The leach rate increases with rising redox potential (Eh) of leaching solution and temperature, and slightly decreases with leaching time. The electrochemical study indicates that the alloy is more stable than carbon steel against corrosion but less stable than copper and stainless steel. Based on the leach rates of Mo, Ru, Rh, Pd and oxidation potentials of these four metals and Tc0, the leach rates of Tc from alloy aggregates, 40%Mo, 30%Ru, 10%Tc, 15% Pd, 5%Rh in spent fuel at reducing and air saturated conditions are estimated, to be 4.10−9 g.cm−2.day−1 and 4. 10−7 g.cm−2.day−1, respectively.