Refine your search:     
Report No.
 - 
Search Results: Records 1-10 displayed on this page of 10
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Predictive modeling of a simple field matrix diffusion experiment addressing radionuclide transport in fractured rock. Is it so straightforward?

Soler, J. M.*; Neretnieks, I.*; Moreno, L.*; Liu, L.*; Meng, S.*; Svensson, U.*; Iraola, A.*; Ebrahimi, K.*; Trinchero, P.*; Molinero, J.*; et al.

Nuclear Technology, 208(6), p.1059 - 1073, 2022/06

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

The SKB Task Force is an international forum on modelling of groundwater flow and solute transport in fractured rock. The WPDE experiments are matrix diffusion experiments in gneiss performed at the ONKALO underground facility in Finland. Synthetic groundwater containing several conservative and sorbing tracers was injected along a borehole interval. The objective of Task 9A was the predictive modelling of the tracer breakthrough curves from the WPDE experiments. Several teams, using different modelling approaches and codes, participated in this exercise. An important conclusion from this exercise is that the modelling results were very sensitive to the magnitude of dispersion in the borehole opening, which is related to the flow of water. Focusing on the tails of the breakthrough curves, which are more directly related to matrix diffusion and sorption, the results from the different teams were more comparable.

Journal Articles

Evaluation report of Task 9C based on comparisons and analyses of modelling results for the ONKALO REPRO-TDE experiment

Soler, J. M.*; Kek$"a$l$"a$inen, P.*; Pulkkanen, V.-M.*; Moreno, L.*; Iraola, A.*; Trinchero, P.*; Hokr, M.*; $v{R}$$'i$ha, J.*; Havlov$'a$, V.*; Trpko$v{s}$ov$'a$, D.*; et al.

SKB TR-21-09, 204 Pages, 2021/11

Journal Articles

Evaluation report of Task 9B based on comparisons and analyses of modelling results for the $"A$sp$"o$ HRL LTDE-SD experiments

Soler, J. M.*; Meng, S.*; Moreno, L.*; Neretnieks, I.*; Liu, L.*; Kek$"a$l$"a$inen, P.*; Hokr, M.*; $v{R}$$'i$ha, J.*; Vete$v{s}$n$'i$k, A.*; Reimitz, D.*; et al.

SKB TR-20-17, 71 Pages, 2021/07

Task 9B of the SKB Task Force on Modelling of Groundwater Flow and Transport of Solutes in fractured rock focused on the modelling of experimental results from the LTDE-SD in situ tracer test performed at the $"A$sp$"o$ Hard Rock Laboratory in Sweden. Ten different modelling teams provided results for this exercise, using different concepts and codes. Three main types of modelling approaches were used: (1) analytical solutions to the transport-retention equations, (2) continuum-porous-medium numerical models, and (3) microstructure-based models accounting for small-scale heterogeneity (i.e. mineral grains and microfracture distributions). The modelling by the different teams allowed the comparison of many different model concepts, especially in terms of potential zonations of rock properties (porosity, diffusion, sorption), such as the presence of a disturbed zone at the rock and fracture surface, the potential effects of micro- and cm-scale fractures.

Journal Articles

Evaluation and modelling report of Task 9A based on comparisons and analyses of predictive modelling results for the REPRO WPDE experiments; Task 9 of SKB Task Force GWFTS - Increasing the realism in solute transport modelling based on the field experiments REPRO and LTDE-SD

Soler, J. M.*; Neretnieks, I.*; Moreno, L.*; Liu, L.*; Meng, S.*; Svensson, U.*; Trinchero, P.*; Iraola, A.*; Ebrahimi, H.*; Molinero, J.*; et al.

SKB R-17-10, 153 Pages, 2019/01

The SKB Task Force is an international forum on modeling of groundwater flow and solute transport in fractured rock. The WPDE experiments are matrix diffusion experiments in gneiss performed at the ONKALO underground facility in Finland. Synthetic groundwater containing several conservative and sorbing tracers was injected along a borehole interval. The objective of Task 9A was the predictive modeling of the tracer breakthrough curves from the WPDE experiments. Several teams, using different modelling approaches, participated in this exercise. An important conclusion from this exercise is that the modeling results were very sensitive to the magnitude of dispersion in the borehole opening, which is related to the flow of water. Focusing on the tails of the breakthrough curves, which are more directly related to matrix diffusion and sorption, the results from the different teams were more comparable. The modeling results have also been finally compared to the measured breakthroughs.

Journal Articles

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

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Eikenberg, J.*; Martin, A. J.*

Journal of Contaminant Hydrology, 179, p.89 - 101, 2015/08

 Times Cited Count:33 Percentile:84.06(Environmental Sciences)

Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na$$^{+}$$, Cs$$^{+}$$) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities (De) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that De and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results.

Journal Articles

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

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Martin, A. J.*

Materials Research Society Symposium Proceedings, Vol.1665, p.85 - 91, 2014/09

Matrix diffusion is a key process for radionuclide retention in crystalline rocks. An in-situ diffusion experiment in granite matrix was performed at the Grimsel Test Site (Switzerland). Several tracers (HTO, Na$$^{+}$$, Cs$$^{+}$$) were circulated through a borehole and the decrease in tracer concentrations was monitored for 2.5 years. Then, the borehole section was overcored and the tracer profiles in the rock were analyzed. Transport distances in the rock were 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusivities ($$D$$e) and rock capacity factors. There was a rather good agreement between the values from different teams, implied that $$D$$e and capacity factors in the borehole damaged zone are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results, which have to be investigated in more detail.

Journal Articles

LTD experiment; Postmortem modelling of monopole I

Soler, J. M.*; Landa, J.*; Havlov$'a$, V.*; Tachi, Yukio; Ebina, Takanori*; Sardini, P.*; Siitari-Kauppi, M.*; Martin, A.*

Nagra NAB 12-53, 80 Pages, 2013/02

An in-situ long-term diffusion (LTD) experiment was performed at the Grimsel Test Site (Switzerland). Tracers, HTO, $$^{22}$$Na$$^{+}$$, $$^{134}$$Cs$$^{+}$$, were continuously circulated through a packed-off borehole and the tracer concentrations in the solution was monitored for 2.5 years. Subsequently, the borehole section was overcored and the tracer profiles in the rock analyzed. The drop in activity for Cs$$^{+}$$ in the solution was much pronounced. Transport distances were about 20 cm for HTO, 10 cm for Na$$^{+}$$ and 1 cm for Cs$$^{+}$$. The dataset was analyzed with diffusion-sorption models by different teams using different codes, with the goal of obtaining effective diffusion coefficients ($$D$$$$_{e}$$) and rock capacity ($$alpha$$) values. There was a rather good agreement between the values from different teams, implied that $$D$$$$_{e}$$ and $$alpha$$ values in the BDZ are larger than those in the bulk rock. However, HTO seems to display large discrepancies between measured and modeled results, which have to be investigated in more detail.

Journal Articles

A Comparative study of the modelling of cement hydration and cement-rock laboratory experiments

Savage, D.*; Soler, J. M.*; Yamaguchi, Kohei; Walker, C.; Honda, Akira; Inagaki, Manabu; Watson, C.*; Wilson, J.*; Benbow, S.*; Gaus, I.*; et al.

Applied Geochemistry, 26(7), p.1138 - 1152, 2011/07

 Times Cited Count:16 Percentile:46.86(Geochemistry & Geophysics)

The use of cement and concrete as fracture grouting or as tunnel seals in a geological disposal facility for rad wastes creates potential issues concerning chemical reactivity. From a long term safety perspective, it is desirable to be able model these interactions and changes quantitatively. As part of the LCS (Long-term Cement Studies) project programme, a modelling inter-comparison has been conducted, involving the modelling of two experiments describing cement hadration and cement-rock reaction, with teams representing the NDA (UK), Posiva (Finland), and JAEA. This modelling exercise showed that the dominant reaction pathways in the two experiments are fairly well understood and are consistent between the different modelling teams, although significant differences existed amongst the precise parameterisation. Future modelling exercises of this type should focus on a suitable natural or industrial analogue that might aid assessing mineral-fluid reactions at these longer timescales.

Oral presentation

The GTS-LTD MONOPOLE-2 experiment at grimsel; Predictive modeling and comparison with monitoring data

Soler, J. M.*; Martin, A. J.*; Lanyon, G. W.*; Havlov$'a$, V.*; Siitari-Kauppi, M.*; Tachi, Yukio

no journal, , 

An in-situ long-term diffusion (LTD) project has been performed at the Grimsel Test Site, Switzerland, to realistically evaluate matrix diffusion of radionuclides in crystalline rock with minimal disturbance to in-situ conditions. A second in situ diffusion experiment (monopole 2) has been performed. Predictive calculations for the monopole-2 experiment, based on results from monopole 1 or from through-diffusion experiments have been compared to monitoring data from the injection and observation boreholes. For the non-sorbing tracers (HTO, $$^{36}$$Cl$$^{-}$$), the diffusion parameters from the through-diffusion experiments provide a better match for the measurements, especially in the injection borehole. The initial drop in activities for $$^{134}$$Cs$$^{+}$$ and $$^{133}$$Ba$$^{2+}$$ shows clearly the effect of sorption. Bulk rock parameters for $$^{134}$$Cs$$^{+}$$ from monopole 1 seem to be applicable to monopole 2. However, $$^{133}$$Ba$$^{2+}$$ seems to sorb more strongly than expected.

Oral presentation

SKB GWFTS task force; Predictive modeling of a matrix diffusion experiment in gneiss at ONKALO (Finland)

Soler, J. M.*; L$"o$fgren, M.*; Nilsson, K.*; Lanyon, G. W.*; Gylling, B.*; Vidstrand, P.*; Neretnieks, I.*; Moreno, L.*; Liu, L.*; Meng, S.*; et al.

no journal, , 

The GWFTS Task Force is an international forum in the area of modeling of groundwater flow and solute transport in fractured rock. The WPDE experiments are matrix diffusion experiments in gneiss performed at the ONKALO underground facility in Finland. Synthetic groundwater containing several conservative and sorbing radiotracers was injected along a borehole interval. The objective of Task 9A of Task Force was the predictive modeling of the tracer breakthrough curves from the WPDE experiments. Several teams, using different modeling approaches, participated in this exercise. An important conclusion from this exercise is that the modeling results were very sensitive to the magnitude of dispersion in the borehole opening, which is related to the flow of water. Focusing on the tails of the breakthrough curves, which are more directly related to matrix diffusion and sorption, the results from the different teams were more comparable.

10 (Records 1-10 displayed on this page)
  • 1