Dissolution of used Candu Fuel at Various Temperatures and Redox Conditions

Abstract

AbstractSamples of used UO2 fuel exposed to air-saturated water at 25°C for eight years have been examined using electron microscopy and X-ray diffraction techniques. The results, in conjunction with solution analysis uata, show evidence for a UO3.2H2O precipitate on the fuel surface, and confirm the importance of grain-boundary leaching in controlling Cs-137 release. Studies of useo-fuel dissolution under both oxidizing and reducing conditions at 150°C show significantly lower radionuclide release to solution for reducing conditions, illustrating the potential importance of reoox chemistry in determining the long-term stability of used fuel after disposal.