IC-ICP-MS applied to the separation and determination of traces of plutonium and uranium in aqueous leachates and acid rinse solutions of UO2 doped with 238Pu

Abstract It is expected that spent nuclear fuel, today mainly UO 2 , may become exposed to groundwater after extended storage in a deep geologic repository. After 1000 years, the radioactivity of the fuel will be constituted essentially by α-emissions by long-lived actinides. The α-emissions play a significant role in determining the dissolution behavior of uranium, because the radiolysis of water results in the formation of oxidizing chemical species near the fuel surface. In order to study this effect, UO 2 doped with ∼0.1 and ∼10 wt.% of a strong α-emitter (namely 238 Pu) was subject to leaching at room temperature (RT) in deionized water. In order to study the mechanisms of leaching in simulated conditions, very precise and accurate techniques need to be employed. In this paper, the results obtained by inductively coupled plasma mass spectrometry coupled with ion chromatography for the determination of traces of 238 Pu and uranium in aqueous leachates’ solutions are illustrated.