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Dissolution of UO2(s) in MgCl2-Brines Under Different Redox Conditions.

Published online by Cambridge University Press:  01 January 1992

Ignasi Casas ,
J. Gimenez ,
J. De Pablo  and
M.E. Torrero
Ignasi Casas
Affiliation:
Department of Chemical Engineering, Universitat Politècnica Catalunya, E-08028 Barcelona, Spain
J. Gimenez
Affiliation:
Department of Chemical Engineering, Universitat Politècnica Catalunya, E-08028 Barcelona, Spain
J. De Pablo
Affiliation:
Department of Chemical Engineering, Universitat Politècnica Catalunya, E-08028 Barcelona, Spain
M.E. Torrero
Affiliation:
Department of Chemical Engineering, Universitat Politècnica Catalunya, E-08028 Barcelona, Spain
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Abstract

The dissolution of unirradiated UO2(s), with a particle size of 1 mm, has been studied in MgCl2 brines at 298 K under both reducing and oxidizing conditions. Results obtained under reducing conditions (H atmosphere in the presence of a palladium catalyst) show an initial increase of the total uranium concentration in solution and a subsequent decrease until equilibrium (or steady state) values are reached. Results obtained under oxidizing conditions (nominal oxygen partial pressures of 0.05, 0.21 and 1 atm) show two different trends. A relatively fast initial dissolution rate and, after approximately two or three weeks, a slower dissolution rate. X-Ray Photoelectron Spectroscopy (XPS) has shown that the UO2 surface composition changes during the experiment.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 294: Symposium V – Scientific Basis for Nuclear Waste Management XVI , 1992 , 67
Copyright
Copyright © Materials Research Society 1993

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References

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