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Mineralogical changes and associated decrease in tritiated water diffusivity after alteration of cement–bentonite interfaces

Published online by Cambridge University Press:  02 January 2018

Tetsuji Yamaguchi*
Affiliation:
Nuclear Safety Research Center, Sector of Nuclear Safety Research and Emergency Preparedness, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Takuma Sawaguchi
Affiliation:
Nuclear Safety Research Center, Sector of Nuclear Safety Research and Emergency Preparedness, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Manabu Tsukada
Affiliation:
Nuclear Safety Research Center, Sector of Nuclear Safety Research and Emergency Preparedness, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
Seiichi Hoshino
Affiliation:
Central Research Laboratory, Taiheiyo Cement Corp., 2-4-2 Osaku, Sakura, Chiba 285-8655, Japan
Tadao Tanaka
Affiliation:
Nuclear Safety Research Center, Sector of Nuclear Safety Research and Emergency Preparedness, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
*
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Abstract

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Alteration of cement–bentonite interfaces and accompanying changes in diffusivity of tritiated water (HTO) was investigated experimentally using intact, hardened cement-paste specimens. The alteration by carbonate solution was accompanied by mineralogical changes at the interface and a decrease in the HTO diffusivity to ∼70 ± 7%of the initial value after a 180-day period. Another alteration in contact with compacted bentonite was accompanied by mineralogical changes at the interface and a decrease in the HTO diffusivity to ∼71 ± 10% of the initial value after a 600-day period. The changes in the diffusivity were considerably less than those observed for mixed specimens of ground, granulated hardened cement paste and bentonite where the diffusivity decreased to 20% of the initial value over 180 days. The results were extrapolated to 15 y under simple assumptions and showed good agreement with those observed in the cement–argillite interface at Tournemire URL (France). Such an explanation enhances confidence in the assessment of the alteration of cement-bentonite systems and might be a basis for using the data and models obtained in the long-term assessment of radioactive waste disposal.

Type
Research Article
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

References

Bartier, D., Techer, I., Dauzeres, A., Boulvais, P., Blanc-Valleron, M.-M. & Cabrera, J. (2013) In situ investigation and reactive transport modelling of cement paste/ argillite interactions in a saturated context and outside an excavated disturbed zone. Applied Geochemistry, 31, 94108.10.1016/j.apgeochem.2012.12.009CrossRefGoogle Scholar
De Windt, L., Marsal, F., Tinseau, E. & Pellegrini, D. (2008) Reactive transport modeling of geochemical interactions at a concrete/argillites interface, Tournemire site (France). Physics and Chemistry of the Earth, 33, S295S305.10.1016/j.pce.2008.10.035Google Scholar
Fernández, R., de la Villa, R.V., Ruiz, A.I., Garcia, R. & Cuevas, J. (2013) Precipitation of chlorite-like structures during OPC porewater diffusion through compacted bentonite at 90°C. Applied Clay Science, 83-84, 357367.10.1016/j.clay.2013.07.021CrossRefGoogle Scholar
Gaboreau, S., Prêt, D., Tinseau, E., Claret, F., Pellegrini, D. & Stammose, D. (2011) 15 years of in situ cement-argillite interaction from Tournemire URL: Characterization of the multi-scale spatial heterogeneities of pore space evolution. Applied Geochemistry, 26, 21592171.10.1016/j.apgeochem.2011.07.013CrossRefGoogle Scholar
Hoshino, S., Yamaguchi, T., Maeda, T., Mukai, M., Tanaka, T. & Nakayama, S. (2009) Mineralogical changes of cement and bentonite accompanied with their interactions. Pp. 445-52 in: Scientific Basis for NuclearWaste Management, XXXIII (B.E. Burakov & A.S. Aloy, editors). Cambridge University Press, UK.Google Scholar
Japanese Standard Association (2011) Chemical analysis method of cement by X-ray fluorescence, JIS R 5204: 2002. Pp. 893-903 in: JIS Handbook 10, Ready-mixed Concrete — 2011. Japanese Standard Association, Tokyo (in Japanese).Google Scholar
Tinseau, E., Bartier, D., Hassouta, L., Devol-Brown, I. & Stammose, D. (2006) Mineralogical characterization of the Tournemire argillite after in situ interaction with concretes. Waste Management, 26, 789800.10.1016/j.wasman.2006.01.024CrossRefGoogle ScholarPubMed
Yamaguchi, T., Negishi, K., Hoshino, S. & Tanaka, T. (2009) Modeling of diffusive mass transport in micropores in cement based materials. Cement and Concrete Research, 39, 11491155.10.1016/j.cemconres.2009.08.012Google Scholar