Irradiation Defects in UO2 Leached in Oxidizing Water: An in-situ Raman Study

In this study, the behavior of irradiation induced defects in UO2 in a specific oxidizing water environment was investigated under alpha irradiation. Raman spectroscopy was used to measure the formation kinetics of irradiation defects in UO2 when exposed to an aerated medium. The acquired data were then compared with a reference UO2/(Ar+H2) system. The results revealed that the presence of either aerated deionized water or reducing environment modifies the formation kinetics of irradiation defects. In addition, the precipitation of the studtite phase is also observed during the leaching experiment and water chemical analysis showed that the dissolution of UO2 proceeds without the formation of an oxidized UO2+x.layer.