Long-term diffusion experiment at Mont Terri: first results from field and laboratory data

Wersin, Paul; Loon, Luc R. Van; Soler, Josep M.; Yllera, A.; Eikenberg, J.; Gimmi, Thomas; Hernán, Pedro; Boisson, Jean-Yves

doi:10.1016/j.clay.2003.09.007

Cited by 98 publications

(58 citation statements)

References 5 publications

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“…Representativeness was also an issue for the in situ tests. One of the field studies (Palut et al 2003) suggested the existence of a borehole disturbed zone (BdZ), but all the other studies (Van Loon et al 2004b;Wersin et al 2004;Soler et al 2008;Wersin et al 2008;Gimmi et al 2014) did not report such an effect. Even though some differences in transport and retention properties were observed, the laboratory values obtained in smaller-scale diffusion experiments could generally be confirmed.…”

Section: Introductionmentioning

confidence: 99%

“…Conceptually, the models for the earlier experiments considered single tracer diffusion only (e.g. Palut et al 2003;Tevissen et al 2004;Van Loon et al 2004b;Yllera et al 2004;Wersin et al 2004;Soler et al 2008;Wersin et al 2008). That is, transport of a tracer (neutral, anion and/or cation) was assumed to be independent of that of any other solute.…”

Section: Concept and Modelling Of The Diffusion Experimentsmentioning

confidence: 99%

“…in the DI-A1 and DI-A2 experiments, which was injected at concentrations large enough to experience non-linear sorption, was also initially modelled as a single tracer. Non-linear sorption was included through Freundlich sorption isotherms (Van Loon et al 2004b;Wersin et al 2004Wersin et al , 2008. Later, a multi-component approach allowed the use of a more mechanistic cation-exchange model (Appelo and Wersin 2007;Appelo et al 2010;Soler et al 2013Soler et al , 2014.…”

Section: Concept and Modelling Of The Diffusion Experimentsmentioning

confidence: 99%

“…Palut et al 2003;Van Loon et al 2004b;Wersin et al 2004;Yllera et al Editorial handling: P. Bossart and A. G. Milnes. This is paper #20 of the Mont Terri Special Issue of the Swiss Journal of Geosciences (see Bossart et al 2017, Wersin et al 2008;Gimmi et al 2014). A main interest was the comparison of results with those from laboratory experiments performed on small samples (in the order of a few cm) of the same material.…”

Section: Introductionmentioning

confidence: 99%

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Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

et al. 2017

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Transport and retardation parameters of radionuclides, which are needed to perform a safety analysis for a deep geological repository for radioactive waste in a compacted claystone such as Opalinus Clay, must be based on a detailed understanding of the mobility of nuclides at different spatial scales (laboratory, field, geological unit). Thanks to steadily improving experimental designs, similar tracer compositions in different experiments and complementary small laboratory-scale diffusion tests, a unique and large database could be compiled. This paper presents the main findings of 20 years of diffusion and retention experiments at the Mont Terri rock laboratory and their impact on safety analysis.

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Section: Introductionmentioning

confidence: 99%

Section: Concept and Modelling Of The Diffusion Experimentsmentioning

confidence: 99%

Section: Concept and Modelling Of The Diffusion Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

et al. 2017

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“…Extensive studies on the Opalinus clay (Switzerland) and Callovo-Oxfordian clay (France) have shown that the diffusion in these media is prominent in the direction parallel to the bedding plane (e.g., Van Loon et al, 2004a, 2004bGarcía-Gutiérrez et al, 2006Samper et al, 2008a). Numerical models of in-situ experiments performed in these areas have treated directional diffusivities as a diffusion tensor of rank two (e.g., Wersin et al, 2004;Yllera et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

An axisymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

Takeda¹,

Hiratsuka²,

Ito³

et al. 2011

Journal of Contaminant Hydrology

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Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured.To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution.The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in-and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. Page 2 of 31The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an axisymmetric diffusion experiment coupled with tracer profiling may be a promising approach to estimate of diffusion anisotropy of sedimentary rocks.

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Multi‐species diffusion analysis in porous media under various dry density and temperature conditions: molecular dynamics simulation, homogenization analysis, and finite element method

Choi

Kawamura

Kimoto

et al. 2014

Num Anal Meth Geomechanics

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In porous media, chemical species that dissolve in pore water can be transported via diffusion mechanisms or advective fluxes, close to or far away from where precipitation occurs. In the case of a high-level radioactive waste disposal system, compacted bentonite is used in a buffer material in an engineering barrier system to minimize the amount of specific nuclides that breach into the surrounding host rock. To minimize breaching, it is very important to understand the transport mechanism of multiple chemical species in porous media. In the following research, we introduced FEM analysis methods using the results of the molecular dynamics simulation and homogenization analysis (MD/HA) method. First, the diffusion coefficients of ions (Cl À , I À , and Na + ) in different water layers of Na-beidellite were calculated using the MD/HA procedure under various dry density (1.2, 1.6, and 2.0 Mg/m 3 ) and temperature (293, 323, and 363 K) conditions. Next, using FEM analysis that used the MD/HA results as input parameters, the diffusion behaviors of ions in porous media were calculated. The results indicate that the diffusion coefficients of the interlayer water in Na-beidellite are different from the diffusion coefficients under dry density conditions. Further, the concentration profiles (C t /C 0 ) of iodine and chloride are proportional to temperature but inversely proportional to dry density. Figure 15. C t /C 0 results of Cl À under various temperature conditions (293, 323, and 353 K) given by the finite element method analysis.Figure 16. C t /C 0 results of I À under various temperature conditions (293, 323, and 353 K) given by the finite element method analysis. MULTI-SPECIES DIFFUSION ANALYSIS IN POROUS MEDIA

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Long-term diffusion experiment at Mont Terri: first results from field and laboratory data

Cited by 98 publications

References 5 publications

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

An axisymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

Multi‐species diffusion analysis in porous media under various dry density and temperature conditions: molecular dynamics simulation, homogenization analysis, and finite element method

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