Grimsel Test Site

Fig. 8. Radionuclide migration studied in a granitic shear zone at the Grimsel test site, Switzerland (injection flow rate 10 mL/min extraction flow rate 150 mL/min, dipole distance 2.3 m). Am(III), Pu(IV) and Th(IV) are co-eluted with the colloids grey vertical lines indicate maxima of breakthrough curves (Geckeis et al. 2003). In order to allow a direct comparison of breakthrough curves, the colloid and radionuclide concentrations (c in mg/mL) in the extracted water samples are normalized to the total injected mass of individual colloid or radionuclide tracers (mn in mg).

Mori, A., Alexander, W. R. et al. 2003. The colloid and radionuclide retardation experiment at the grimsel test site Influence of bentonite colloids on radionuclide migration in a fractured rock. Colloids Surfaces, 217, 33-47. 

Figure 8.6 Size distributions (particles below lpm) based on particle number for different natural water systems Gulf of Mexico (Harris, 1977), foraminifera and diatoms from near-surface South-lndian Ocean (Lai and Lerman, 1975), coastal surface waters of North Pacific Ocean (off Tokyo Bay) (Koike et al., 1990), Grimsel test site groundwater (Switzerland) (Degueldre, 1990), Markham Clinton groundwater (UK) (Longworth et al., 1990), amorphous iron oxy(hydroxo)phos-phate at the oxic/anoxic boundary of Lake Bret (Switzerland) (Buffle et al., 1989), Rhine River (The Netherlands) (van de Meentef al., 1983), Rhine River (Basle, Switzerland) (Newman etal., 1994), St Lawrence River (Canada) (Comba and Kaiser, 1990). Distributions recalculated from the original data as explained in Filella and Buffle (1993) (reproduced from Filella and Buffle, 1993, by permission of the copyright holders, Elsevier Science Publishers BV, Amsterdam).

Degueldre C., Baeyens B., Goerlich W., Riga J., Verbist J., and Stadelmann P. (1989) Colloids in water from a subsurface fracture in granitic rock, Grimsel test site. Geochim. Cosmochim. Acta 53, 603 -610. 

Gillow J. B., Dunn M., Francis A. L, Lucero D. A., and Papenguth H. W. (2000) The potential for subterranean microbes in facilitating actinide migration at the Grimsel Test Site and Waste Isolation Pilot Plant. Radiochim. Acta 88(9-11), 769-774. 

The Febex in situ test is currently in operation at the Grimsel Test Site, located in the granitic rocks of the Aare Massif in central Switzerland. 

Keusen, H.R., Ganguin, J., Schuler, P., and Buletti, M.. Grimsel Test Site. Geology. NAGRA, NTB 87-14E, 1989. 

Pahl, A., Heusertnann, St., Brauer, V. and Gldggler, W., Grimsel Test Site. Rock stress investigations. NAGRA, NTB 88-39E, 1989. 

Abstract Coupled THM simulation of the FEBEX, which is the full-scale in-situ Engineered Barrier System Experiment performed in Grimsel Test Site in Switzerland, is one Task in the international cooperation project DECOVALEX III. In the Task, the simulation of the thermal, hydraulic and mechanical behaviour in the buffer during heating phase is required, e.g. the evolutions and the distributions of stress, relative humidity and temperature at the specified points in bentonite buffer material. 

The FEBEX is the full-scale in-situ Engineered Barrier System (EBS) Experiment performed in Grimsel Test Site (GTS) in Switzerland (enresa (2000)). The simulation of the coupled thermal, hydraulic and mechanical (THM) behaviour of FEBEX is the task of the DECOVALEX (DEvelopment of COupled models and their VALidation against Experiments) III. 

Pardillo J. and Campos R. (1996). FEBEX -Grimsel Test Site (Switzerland) Considerations respect to the fracture distribution. CIEMAT, 70-IMA-L-2-05, Mar. 1996. 

Figure I. Pressure changes in borehole FEX 95.002 induced by the TBM drilling of the FEB EX tunnel at the Grimsel Test Site (McKinley et al 1996).

As part of the DECOVALEX III project, several independent research teams have used various numerical models to analyze a full-scale engineered barrier experiment (FEBEX), currently conducted at the Grimsel Test Site in Switzerland. This paper presents the analysis conduced by the Berkeley Lab research team, using the fully coupled thermal-hydrological-mechanical (THM) numerical model ROCMAS. Specifically, the paper presents model predictions of coupled THM responses at FEBEX that are compared to field measurements. 

Figure /. The set up of the FEBEX in situ test located at the Grimsel Test Site about 420 m below the ground surface.

As shown in Table 2, the properties of the Lamprophyre properties and the surrounding rock are the same except for permeability and thermal conductivity. The mechanical rock-mass properties are obtained from the geological description of the Grimsel Test Site (Kneussen et al., 1989). Significantly, the Young s modulus of the rock mass was reduced to 70% of its value for intact rock. 

Figure I. Location of the various Grimsel Test Site tunnels, Pardillo etal. (1997).

Vobomy O., Adank P., Hurlimann W., Vomvoris S. Mishra S. 1991. Grimsel Test Site. Modelling of groundwater flow in the rock body surrounding the underground laboratory. NAGRA, NTB 91-03. 

A large scale in situ heating test is being performed at the Grimsel Test Site, an underground research laboratory located in the Swiss Alps. The rock in the site is mainly granite. The test tries to... 

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