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Influence of sample preparation on MX-80 bentonite microstructure

Published online by Cambridge University Press:  02 January 2018

M. Matusewicz ,
V.-M. Pulkkanen  and
M. Olin
M. Matusewicz*
Affiliation:
VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Finland
V.-M. Pulkkanen
Affiliation:
VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Finland
M. Olin
Affiliation:
VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Finland
*
*E-mail: Michal.Matusewicz@vtt.fi
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Abstract

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Compacted bentonite is to be used as a buffer material between waste canisters and the bedrock in the deep geological disposal of high-level nuclear waste in several countries. In spite of the fact that such large bentonite systems have long equilibration times, estimation of the material properties and performance in repository conditions is often based on short-term, laboratory-scale experiments. Sample-preparation procedures in these experiments may differ from the natural evolution of the bentonite in the repository, however, affecting the bentonite properties. The present study reports the influence on the structure of clay tactoids of four different preparation procedures of water-saturated, compacted MX-80 bentonite samples using four target dry bulk densities. Small-angle X-ray scattering was used to illustrate the differences between the samples. The different treatments of the bentonite samples may lead to different structural features. Clear differences between low-density samples prepared using different procedures were observed. The influence of the preparation methods was less, but still noticeable, for the high-density samples.

Keywords

MX-80bentonitebuffermicrostructurerepository conditionssmall-angle X-ray scattering
Type
Research Article
Information
Clay Minerals , Volume 51 , Issue 2 , May 2016 , pp. 189 - 195
Creative Commons
Creative Common License - CCCreative Common License - BY
Copyright © The Mineralogical Society of Great Britain and Ireland 2016 This is an Open Access article, distributed under the terms of the Creative Commons Attribution license. (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

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