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 Pu-238

摘要

It is expected that spent nuclear fuel, today mainly UO2, 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 alpha -emissions by long-lived actinides. The alpha -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, UO2 doped with similar to 0.1 and similar to 10 wt.% of a strong alpha -emitter (namely Pu-238) 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 Pu-238 and uranium in aqueous leachates' solutions are illustrated. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 6]