Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-15T19:19:53.173Z Has data issue: false hasContentIssue false
  • English
  • Français

Modeling of an in-situ diffusion experiment in granite at the Grimsel Test Site

Published online by Cambridge University Press:  30 June 2014

Josep M. Soler ,
Jiri Landa ,
Vaclava Havlova ,
Yukio Tachi ,
Takanori Ebina ,
Paul Sardini ,
Marja Siitari-Kauppi  and
Andrew J. Martin
Josep M. Soler
Affiliation:
IDAEA-CSIC, Barcelona, Catalonia, Spain.
Jiri Landa
Affiliation:
UJV-Rez, Husinec-Rez, Czech Republic.
Vaclava Havlova
Affiliation:
UJV-Rez, Husinec-Rez, Czech Republic.
Yukio Tachi
Affiliation:
JAEA, Tokai, Japan.
Takanori Ebina
Affiliation:
JAEA, Tokai, Japan.
Paul Sardini
Affiliation:
University of Poitiers, France.
Marja Siitari-Kauppi
Affiliation:
University of Helsinki, Finland.
Andrew J. Martin
Affiliation:
NAGRA, Wettingen, Switzerland.
Get access

Abstract

Matrix diffusion is a key process for radionuclide retention in crystalline rocks. Within the LTD project (Long-Term Diffusion), an in-situ diffusion experiment in unaltered non-fractured granite was performed at the Grimsel Test Site (www.grimsel.com, Switzerland). The tracers included 3H as HTO, 22Na+, 134Cs+ and 131I- with stable I- as carrier.

The dataset (except for 131I- because of complete decay) was analyzed with different diffusion-sorption models by different teams (NAGRA / IDAEA-CSIC, UJV-Rez, JAEA, Univ. Poitiers) using different codes, with the goal of obtaining effective diffusion coefficients (De) and porosity (ϕ) or rock capacity (α) values. A Borehole Disturbed Zone (BDZ), which was observed in the rock profile data for 22Na+ and 134Cs+, had to be taken into account to fit the experimental observations. The extension of the BDZ (1-2 mm) was about the same magnitude as the mean grain size of the quartz and feldspar grains.

De and α values for the different tracers in the BDZ are larger than the respective values in the bulk rock. Capacity factors in the bulk rock are largest for Cs+ (strong sorption) and smallest for 3H (no sorption). However, 3H seems to display large α values in the BDZ. This phenomenon will be investigated in more detail in a second test starting in 2013.

Keywords

diffusiongeologictransportation
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1665: Symposium NW – Scientific Basis for Nuclear Waste Management XXXVII , 2014 , pp. 85 - 91
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Soler, J.M., Landa, J., Havlova, V., Tachi, Y., Ebina, T., Sardini, P., Siitari-Kauppi, M. and Martin, A., LTD Experiment. Postmortem Modelling of Monopole I, (Nagra Arbeitsbericht NAB 12-53, Wettingen, 2013), p.80.Google Scholar
Steefel, C.I., CrunchFlow. Software for Modeling Multicomponent Reactive Flow and Transport. User’s Manual, (Lawrence Berkeley National Laboratory, Berkeley, 2009), p. 91.Google Scholar
GoldSim Technology Group, GoldSim Version 10.1 (2010).Google Scholar
COMSOL Inc., COMSOL Multiphysics Version 4.2 (2011).Google Scholar
Delay, F., Porel, G. and Sardini, P., C. R. Geosci. 334, 967 (2002).CrossRefGoogle Scholar
Sardini, P., Delay, F., Hellmuth, K.-H., Porel, G. and Oila, E., J. Contam. Hydrol. 61, 339 (2003).CrossRefGoogle Scholar
Sardini, P., Robinet, J.C., Siitari-Kauppi, M., Delay, F. and Hellmuth, K.H., J. Contam. Hydrol. 93, 21 (2007).CrossRefGoogle Scholar
Robinet, J.C., Sardini, P., Delay, F. and Hellmuth, K.H., Transp. Porous Media 72 (3), 393 (2008).CrossRefGoogle Scholar
Robinet, J.C., Sardini, P., Coelho, D., Parneix, J.-C., Prêt, D., Sammartino, S., Boller, E. and Altmann, S., Water Resour. Res. 48, No. 5 (2012).CrossRefGoogle Scholar
Möri, A., Phase VI – Pore Space Geometry (PSG) Experiment. In Situ Impregnation of Matrix Pores in Granite Rock – Study of a potential borehole disturbed zone (BDZ), (Nagra Arbeitsbericht NAB 05-19, Wettingen, 2005), p. 24.Google Scholar