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Diffusion of 60Co, 137Cs and 152Eu in Opalinus Clay

Published online by Cambridge University Press:  01 February 2011

Miguel García-Gutiérrez ,
José Luis Cormenzana ,
Tiziana Missana ,
Manuel Mingarro  and
Ursula Alonso
Miguel García-Gutiérrez
Affiliation:
[email protected], CIEMAT, Dept. Medioambiente, Madrid, Spain
José Luis Cormenzana
Affiliation:
[email protected], Empresarios Agrupados, MADRID, Spain
Tiziana Missana
Affiliation:
[email protected], CIEMAT, Dept. Medioambiente, MADRID, Spain
Manuel Mingarro
Affiliation:
[email protected], CIEMAT, Dept. Medioambiente, MADRID, Spain
Ursula Alonso
Affiliation:
[email protected]@gmail.com, CIEMAT, Dept. Medioambiente, MADRID, Spain
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Abstract

This study addresses the diffusion of representative sorbing elements, cobalt, cesium and europium in the Opalinus Clay (OPA). The methodology used here to determine diffusion coefficients is the ‘instantaneous planar source’ method. In this setup, a paper filter impregnated with tracer is introduced between two clay samples, avoiding contact between the tracer and the experimental vessels. The apparent diffusion coefficients (Da) perpendicular to the bedding plane, obtained with this experimental method and fitting the experimental results with an analytical solution, were Da(Co) = (2.4-3.5)·10-14 m2/s, Da(Cs) = (5.9-8.0)·10-14 m2/s, and Da(Eu) = (1.0-2.1)·10-15 m2/s. With cobalt and cesium, classical in-diffusion experiments were also performed for comparison, and similar Da values were obtained but with a large dispersion. To analyze the possible effects of the paper filter impregnated with the tracer on the determinations of Da with the analytical solution, one experiment was also analyzed using a detailed stochastic model of the setup. The good agreement between the two modeling approaches confirms the validity of this experimental setup and the analytical model fitting procedure.

Keywords

diffusionwaste managementEu
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1124: Symposium Q – Scientific Basis for Nuclear Waste Management XXXII , 2008 , 1124-Q07-06
Copyright
Copyright © Materials Research Society 2009

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References

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