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Predicted Behavior of Technetium in a Geological Disposal Vault For Used Nuclear Fuel - Ramifications of a Recent Determination of the Enthalpy of Formation of TcO2(cr)

Published online by Cambridge University Press:  15 February 2011

R. J. Lemire  and
D. J. Jobe
R. J. Lemire
Affiliation:
ECL, Chalk River Laboratories, Chalk River, ON K0J 1J0, Canada
D. J. Jobe
Affiliation:
AECL, Whiteshell Laboratories, Pinawa, MB ROE 1L0, Canada.
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Abstract

Recently, we reported a value of ΔH°(TcO2(cr)) = -(458 ± 6) kJ·mol-1based on heat of solution measurements. The implications of this value on the database used in the Canadian Nuclear Fuel Waste Management Program for the evaluation of the technetium released by congruent dissolution of used UO2 fuel have now been assessed.

It is probable that the Tc(IV) oxides are more stable than previously predicted and, hence, they are less likely to be oxidized to TcO4(aq) under moderately reducing conditions. We have revised earlier calculations done to predict the solution concentrations of technetium species in a vault as a function of the oxidation conditions in model groundwaters.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 412: Symposium V – Scientific Basis for Nuclear Waste Management XIX , 1995 , 873
Copyright
Copyright © Materials Research Society 1996

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