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Modelling evolution in the near field of a cementitious repository

Published online by Cambridge University Press:  05 July 2018

A. R. Hoch ,
G. M. N. Baston ,
F. P. Glasser ,
F. M. I. Hunter  and
V. Smith
A. R. Hoch*
Affiliation:
AMEC, Harwell Science and Innovation Campus, Harwell, Didcot, Oxfordshire OX11 0QB, UK
G. M. N. Baston
Affiliation:
AMEC, Harwell Science and Innovation Campus, Harwell, Didcot, Oxfordshire OX11 0QB, UK
F. P. Glasser
Affiliation:
Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Meston Building, Meston Walk, Aberdeen AB24 3UE, UK
F. M. I. Hunter
Affiliation:
AMEC, Harwell Science and Innovation Campus, Harwell, Didcot, Oxfordshire OX11 0QB, UK
V. Smith
Affiliation:
AMEC, Harwell Science and Innovation Campus, Harwell, Didcot, Oxfordshire OX11 0QB, UK
*
*E-mail: andrew.hoch@amec.com
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Abstract

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In the United Kingdom, disposal of radioactive waste may involve packages of grouted waste being placed in a geological disposal facility (GDF) and surrounded by a cementitious backfill. This paper describes modelling that has been carried out to develop an understanding of the possible spatial and temporal evolution within the GDF.

A single waste package is assumed to be filled with an encapsulation grout, placed in an underground vault and surrounded by a cementitious backfill. Groundwater from the host rock flows into the vault and through the backfill. A simplified model system examines the interactions between groundwater, cementitious backfill and grout.

In most cases the model predicts a reduction in the backfill porosity due to precipitation and dissolution reactions, particularly at the upstream edge of the vault. The degree to which this occurs depends on the groundwater composition. The model also predicts precipitation and dissolution reactions would occur in the grouts close to their interface with the backfill, reducing the local porosity significantly which may isolate the grouts from the backfill, so that the pH within the grouts would be unchanged over an extended period.

Keywords

transport modellingTOUGHREACTcementgeological disposal facilityradioactive waste
Type
Research Article
Information
Mineralogical Magazine , Volume 76 , Issue 8 , December 2012 , pp. 3055 - 3069
Creative Commons
Creative Common License - CCCreative Common License - BY
© [2012] The Mineralogical Society of Great Britain and Ireland. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2012

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