Adsorption of an Uranyl Carbonate Complex onto an Amidoxime Resin

Uranium is a major element in the management of spent nuclear fuel or radioactive waste. Uranium is also present in sea water at a trace level (∼3ppb). Usually, an acid medium in a solvent extraction or ion exchange system have been used for the separation of uranium from a radioactive waste solution. Especially, some adsorbants containing amidoxime functional groups selective for the uranyl ion have been developed for the recovery of uranium in sea water. An amidoxime resin as an anion exchanger synthesized using divinylbenzene copolymer as a supporting material was applied for the separation of uranium and plutonium from simulated fission products in carbonate solution by making an uranyl tricarbonate complex, UO2(CO3)34-, in an alkaline solution of a carbonate (pH>8). A carbonate leaching of uranium from uranium contaminated soils was also successfully performed using a sodium carbonate and a sodium bicarbonate solution. In this work, the distribution coefficients of uranyl ions were measured for the amidoxime resins with a variation of carbonate concentration and the pH of the solutions as a preliminary work for a spent fuel treatment with a strong alkaline carbonate solution because this system has an advantage to reduce a high level waste volume by a selective oxidation and an adsorption of uranium from spent fuels