The dissolution of irradiated UO2 fuel in groundwater

The kinetics of dissolution of irradiated CANDU reactor fuel in oxygenated synthetic groundwaters at 250C have been investigated. Water compositions studied include deionized distilled water, carbonate-rich groundwater, granitic groundwater, and a groundwater representative of some saline solutions found deep within rock of the Canadian Shield. The fission product release kinetics did not vary significantly over the wide range of water compositions. The oxygen content of the solution was shown to have only a small impact on dissolution rates. Evidence for the selective leaching of fission products from irradiated fuel is discussed, as is the potential impact of α-radiolysis on the dissolution process