A fully 3-D anisotropic numerical model of the DI-B in situ diffusion experiment in the Opalinus clay formation

2006 ◽  
Vol 31 (10-14) ◽  
pp. 531-540 ◽  
Author(s):  
J. Samper ◽  
C. Yang ◽  
A. Naves ◽  
A. Yllera ◽  
A. Hernández ◽  
...  
Keyword(s):  
Numerical Model ◽  
Opalinus Clay ◽  
Diffusion Experiment ◽  
In Situ Diffusion ◽  
Clay Formation

DI-B experiment: planning, design and performance of an in situ diffusion experiment in the Opalinus Clay formation

2004 ◽  
Vol 26 (1-4) ◽  
pp. 181-196 ◽  
Author(s):  
A. Yllera ◽  
A. Hernández ◽  
M. Mingarro ◽  
A. Quejido ◽  
L.A. Sedano ◽  
...  
Keyword(s):  
Opalinus Clay ◽  
Experiment Planning ◽  
Diffusion Experiment ◽  
In Situ Diffusion ◽  
And Performance ◽  
Clay Formation

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

2014 ◽  
Vol 1665 ◽  
pp. 85-91 ◽  
Author(s):  
Josep M. Soler ◽  
Jiri Landa ◽  
Vaclava Havlova ◽  
Yukio Tachi ◽  
Takanori Ebina ◽  
...  
Keyword(s):  
Effective Diffusion ◽  
Test Site ◽  
Diffusion Experiment ◽  
Bulk Rock ◽  
Disturbed Zone ◽  
Mean Grain Size ◽  
Grimsel Test Site ◽  
In Situ Diffusion

ABSTRACTMatrix 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.

A Numerical Simulation of Diffusion Experiment in Clay

2011 ◽  
Vol 322 ◽  
pp. 353-356
Author(s):  
Qing Chun Yang
Keyword(s):  
Numerical Simulation ◽  
Opalinus Clay ◽  
Isotropic Case ◽  
Diffusion Experiment ◽  
Deep Geological Repository ◽  
Transport Distance ◽  
Geological Repository ◽  
Geological Formation ◽  
Clay Formation ◽  
Anisotropic Case

Safety assessment of nuclear waste disposal in a deep geological repository requires understanding and quantifying radionuclide transport through the hosting geological formation. Determining diffusion parameters under real conditions is necessary for the performance assessment of a deep geological repository where high level wastes are placed for safety disposal. The in situ diffusion and retention (DR) experiments are designed to study the transport and retention properties of the Opalinus clay formation. In this paper, a scoping numerical simulation is performed in Opalinus Clay, The simulated results for all the traces illustrate that the maximum transport distance perpendicular to the bedding is larger in the isotropic case and those along the bedding is larger in the anisotropic case. Tracer depletion in the isotropic case is a little larger than in the anisotropic case. Deuterium and iodide can be detected in the other interval but strontium can’t. Since the length of injection interval is shorter than the transport distance, the anisotropy effect is clearly measurable. This numerical simulation of diffusion experiment aims at contributing to the optimum design of the experiment. The results of this experiment will provide additional insight into the role of diffusion anisotropy and sorption parameters for radionuclides in clays.

In-Situ Diffusion Experiment In Sparsely Fractured Granite

2004 ◽  
Vol 824 ◽  
Author(s):  
Peter Vilks ◽  
Neil H. Miller ◽  
Mark Jensen
Keyword(s):  
Field Experiments ◽  
Effective Diffusion ◽  
Rock Properties ◽  
Experimental Program ◽  
Diffusion Experiment ◽  
Stress Regime ◽  
In Situ Experiments ◽  
In Situ Diffusion ◽  
Conservative Values

AbstractThe in-situ diffusion experiment was conducted at AECL's Underground Research Laboratory (URL) to improve the understanding of diffusive solute transport in sparsely fractured or intact granitic rock (SFR). The experimental program used a comparative series of laboratory and in-situ field experiments to evaluate the ability of laboratory measurements to estimate in-situ rock properties and to explore issues surrounding the influence of stress relaxation, rock texture, porosity, pore geometry, and anisotropy on derived effective diffusion coefficients (De). In-situ experiments yielded iodide Debetween 1.4 × 10−13 and 1.1 × 10−12 m2/s. Unlike laboratory results, the in-situ De estimates did not exhibit correlation with sample depth or varied stress regime. Laboratory-derived measurements of De, porosity and permeability were found to systematically increase for samples removed from greater depths and higher stress regimes. Laboratory-derived iodide De values consistently trended higher than in-situ values by a factor of 1 to 15, except on the shallowest 240-m Level (σ1 ≍ 30 MPa) where differences were negligible. Laboratory-derived estimates of permeability were consistently higher than in-situ derived values by a factor of 2 to 100. This experimental program provides evidence that laboratory steady-state diffusion experiments are most likely to yield conservative values of De for simulation of diffusive mass transport in SFR.

scholarly journals Comparison between in situ and laboratory diffusion studies of HTO and halides in Opalinus Clay from the Mont Terri

2004 ◽  
Vol 92 (9-11) ◽  
Author(s):  
Etienne Tevissen ◽  
J. M. Soler ◽  
P. Montarnal ◽  
A. Gautschi ◽  
Luc R. Van Loon
Keyword(s):  
Tritiated Water ◽  
Opalinus Clay ◽  
Diffusion Experiment ◽  
Diffusion Technique ◽  
Diffusion Studies ◽  
Through Diffusion ◽  
Mont Terri

SummaryA long-term single-borehole diffusion experiment (DI) using tritiated water (HTO) and stable iodide (All HTO results obtained with a through diffusion technique are within the same range as those obtained in the

In situ diffusion experiment in granite: Phase I

2003 ◽  
Vol 61 (1-4) ◽  
pp. 191-202 ◽  
Author(s):  
P Vilks ◽  
J.J Cramer ◽  
M Jensen ◽  
N.H Miller ◽  
H.G Miller ◽  
...  
Keyword(s):  
Phase I ◽  
Diffusion Experiment ◽  
In Situ Diffusion

Comparative modeling of an in situ diffusion experiment in granite at the Grimsel Test Site

2015 ◽  
Vol 179 ◽  
pp. 89-101 ◽  
Author(s):  
Josep M. Soler ◽  
Jiri Landa ◽  
Vaclava Havlova ◽  
Yukio Tachi ◽  
Takanori Ebina ◽  
...  
Keyword(s):  
Comparative Modeling ◽  
Test Site ◽  
Diffusion Experiment ◽  
Grimsel Test Site ◽  
In Situ Diffusion

The DR-A in-situ diffusion experiment at Mont Terri: Effects of changing salinity on diffusion and retention properties.

2014 ◽  
Vol 1665 ◽  
pp. 63-69 ◽  
Author(s):  
Josep M. Soler ◽  
Olivier X. Leupin ◽  
Thomas Gimmi ◽  
Luc R. Van Loon
Keyword(s):  
British Columbia ◽  
Reactive Transport ◽  
High Salinity ◽  
Transport Modeling ◽  
Reactive Transport Modeling ◽  
Diffusion Experiment ◽  
Predictive Capability ◽  
In Situ Diffusion ◽  
Mont Terri

ABSTRACTIn the new DR-A in-situ diffusion experiment at Mont Terri, a perturbation (replacement of the initial synthetic porewater in the borehole with a high-salinity solution) has been induced to study the effects on solute transport and retention, and more importantly, to test the predictive capability of reactive transport codes. Reactive transport modeling is being performed by different teams (IDAEA-CSIC, PSI, Univ. Bern, Univ. British Columbia, Lawrence Berkeley Natl. Lab.). Initial modeling results using the CrunchFlow code and focusing on Cs+ behavior are reported here.

Sign in / Sign up

Export Citation Format

Share Document