Improvements in the recovery of palladium from reprocessing waste of spent nuclear fuel reported earlier

A collection-precipitation (CP) method and an extraction-collection-precipitation (ECP) method have been investigated for high speed and efficient recovery of palladium from reprocessing waste of spent nuclear fuel. For the CP method, a matrix feedstock solution and a small volume of inert solvent, whose specific gravity is greater than that of feedstock solution, as collecting and protective agent, were powerfully mixed with an appropriate amount of potassium iodide solution at 15°C for 1 minute, recovering PdI₂ precipitate after centrifuging. For the ECP method, an extraction complex K(benzo-15-crown-5)₂I in the same organic solvent as for the CP method was mixed with feedstock solution. For both methods, the percent recovery of palladium is more than 99% and 95% for irradiation doses of 1·10³ and 5·10³ Gy, respectively. Decontamination of the palladium product is good.