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Modeling of UO2 Aqueous Dissolution Over a Wide Range of Conditions

Published online by Cambridge University Press:  25 February 2011

Steven A. Steward  and
Homer C. Weed
Steven A. Steward
Affiliation:
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550
Homer C. Weed
Affiliation:
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550
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Abstract

Previously it was not possible to predict reliably the rate at which spent fuel would react with groundwater because of conflicting data in the literature. The dissolution of the UO2 spent fuel matrix is a necessary step for aqueous release of radioactive fission products. Statistical experimental design was used to plan a set of UO2 dissolution experiments to examine systematically the effects of temperature (25-75°C), dissolved oxygen (0.002-0.2 atm overpressure), pH (8-10) and carbonate (2-200x10-4 molar) concentrations on UO2 dissolution. The average dissolution rate was 4.3 mg/m2/day. The regression fit of the data indicate an Arrhenius type activation energy of -8750 cal/mol·K and a half-power dependence on dissolved oxygen in the simulated groundwater.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 333: Symposium V – Scientific Basis for Nuclear Waste Management XVII , 1993 , 409
Copyright
Copyright © Materials Research Society 1994

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References

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