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Leaching of Nirex Reference Vault Backfill cement by clay, granite and saline groundwaters

Published online by Cambridge University Press:  04 March 2018

Rita G. W. Vasconcelos ,
Andres Idiart ,
Neil C. Hyatt ,
John L. Provis  and
Claire L. Corkhill
Rita G. W. Vasconcelos
Affiliation:
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield (UK)
Andres Idiart
Affiliation:
Amphos 21, Barcelona (ES)
Neil C. Hyatt
Affiliation:
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield (UK)
John L. Provis
Affiliation:
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield (UK)
Claire L. Corkhill*
Affiliation:
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield (UK)
*
*Corresponding author: c.corkhill@sheffield.ac.uk
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Abstract

For the UK geological disposal facility (GDF) concept in a high strength crystalline rock, Nirex Reference Vault Backfill (NRVB) has been considered to use as a cementitious backfill material. The lifetime performance of this high pH material is required to be extremely long, and as a consequence of the interaction with the geological environment (e.g. groundwater), the backfill material will evolve and age with time. In this paper, we present the results of a leaching experiment, where NRVB is placed in contact with three different groundwater compositions representative of granitic, clay and saline groundwater for 35 days. Some differences were observed related with the mineralogy. X-ray Diffraction results showed the formation of more ettringite, mainly in the NRVB samples leached in clay and saline groundwater. An increase of the pH was also observed in the NRVB samples leached with the three different ground waters, being these results in accordance with the reactive transport modelling performed.

Keywords

cement & ampconcretenuclear materialswaste managementchemical composition
Type
Articles
Information
MRS Advances , Volume 3 , Issue 21: Scientific Basis for Nuclear Waste Management XLI , 2018 , pp. 1175 - 1180
Copyright
Copyright © Materials Research Society 2018 

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References

References:

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