Grimsel Test Site - Phase VI: Review of Accomplishments and Next Generation of In-Situ Experiments Under Repository Relevant Boundary Conditions

2008 ◽  
Vol 1107 ◽  
Author(s):  
Ingo Blechschmidt ◽  
Stratis Vomvoris ◽  
Joerg Rueedi ◽  
Andrew James Martin
Keyword(s):  
Near Field ◽  
Planning Horizon ◽  
Test Site ◽  
Low Ph ◽  
Swiss Alps ◽  
In Situ Experiments ◽  
Grimsel Test Site ◽  
And Migration

AbstractThe Grimsel Test Site owned and operated by Nagra is located in the Swiss Alps (www.grimsel.com). The Sixth Phase of investigations was started in 2003 with a ten-year planning horizon. With the investigations and projects of Phase VI the focus has shifted more towards projects assessing perturbation effects of repository implementation and projects evaluating and demonstrating engineering and operational aspects of the repository system. More than 17 international partners participate in the various projects, which form the basic organisational “elements” of Phase VI. Scientific and engineering interaction among the different projects is ensured via an annual meeting and several experimental team meetings throughout the year. On-going projects include: evaluation of full-scale engineered systems under simulated heat production and long-term natural saturation (NF-Pro/FEBEX), gas migration through engineered barrier systems (GMT, finished this year), emplacement of a shotcrete low-pH plug (ESDRED/Module IV), testing and evaluation of standard monitoring techniques (TEM).Numerous in-situ experiments with inactive tracers and radionuclides were successfully carried out over the past few years at the Grimsel Test Site (GTS). For the GTS Phase VI, three major projects have been initiated to simulate the long-term behaviour of contamination plumes in the repository near-field and the surrounding host rock:•The CFM (Colloid Formation and Migration) project, which focuses on colloid generation and migration from a bentonite source doped with radionuclides•The LCS (Long-Term Cement Studies) project, which aims at improving the understanding of low-pH cement interaction effects in water conducting features•The LTD (Long-Term Diffusion) project, which aims at in-situ verification of long-term diffusion concepts for radionuclidesAs Phase VI approaches its mid-term point, what are the next steps planned? The accomplishments assessed to date and the opportunities with the on-going projects as well as new projects – currently under discussion – are presented herein

Grimsel Test Site — Phase VI: Review of Accomplishments and Next Steps

2007 ◽  
Author(s):  
Stratis Vomvoris ◽  
Wolfgang Kickmaier
Keyword(s):  
Ad Hoc ◽  
Field Testing ◽  
Planning Horizon ◽  
Test Site ◽  
Swiss Alps ◽  
Tracer Transport ◽  
Geophysical Investigation ◽  
Grimsel Test Site

The Grimsel Test Site owned and operated by Nagra is located in the Swiss Alps (www.grimsel.com). The sixth Phase of investigations was started in 2003 with a ten-year planning horizon. With the investigations and projects of Phase VI the focus is shifted more towards projects assessing perturbation effects of repository implementation and projects evaluating and demonstrating engineering and operational aspects of the repository system. More than 17 international partners participate in the various projects, which form the basic organisational ‘elements’ of Phase VI, each one further structured in field-testing, laboratory studies, design and modelling tasks, as appropriate. Each project phase is planned with a duration of 3 to 5 years, to facilitate all practical and administrative aspects, ensuring flexibility for updating the overall plan with the recent findings. Scientific and engineering interaction among the different projects is ensured via the annual international meeting and ad-hoc meetings, as appropriate. As Phase VI approaches its mid-term point, a review of the accomplishments to date is performed to provide a sound basis for the detailed planning of the next steps. The accomplishments to date are described and assessed below; the opportunities with the on-going projects as well as new projects – currently under discussion – are also presented and discussed. The on-going projects include: studies of the long-term diffusion with emphasis on the processes in the rock matrix (LTD); colloid studies under in-situ generation conditions and migration velocities closer to velocities expected in an actual repository site (CFM); studies of the long-term cement interactions with natural systems (LCS); evaluation of full-scale engineered systems under simulated heat production and long-term natural saturation (NF-Pro/FEBEX); gas migration through engineered barrier systems (GMT); emplacement of shotcrete low-pH plug (ESDRED/Module IV); test and evaluation of monitoring systems (TEM). In addition, various shorter term projects assessing, for example, new geophysical investigation tools, wireless transmission, testing new tools and training for in-situ tracer transport studies have been performed and/or are planned for the near future.

Studies on radionuclide transport behaviour–The next generation of in-situ experiments at the Grimsel Test Site

2009 ◽  
Vol 1193 ◽  
Author(s):  
Andrew James Martin ◽  
Ingo Blechschmidt
Keyword(s):  
Shear Zone ◽  
Diffusion Processes ◽  
Test Site ◽  
Core Material ◽  
Laboratory Studies ◽  
Grimsel Test Site ◽  
And Migration ◽  
Colloid Formation

AbstractTwo recent ongoing major projects at the Grimsel Test Site (GTS) (www.grimsel.com) that were initiated to simulate the long-term behaviour of radionuclides in the repository near-field and the surrounding host rock are presented: the Colloid Formation and Migration (CFM) project, which focuses on colloid generation and migration from a bentonite source doped with radionuclides and the Long-Term Diffusion (LTD) project, which aims at in-situ verification and understanding of the processes that control the long-term diffusion of repository-relevant radionuclides. So far, the CFM project has principally involved: development and implementation of a state-of-the-art sealing concept to control hydraulic gradients in a shear zone to imitate repository-relevant conditions; extensive laboratory studies to examine bentonite erosion and colloid formation in a shear zone; and, development of models to estimate colloid formation and migration. The next stage will be to assess the behavior of bentonite colloids generated from a radionuclide spiked bentonite source-term emplaced into the controlled flow field of the shear zone. This will be coupled with further extensive laboratory studies in order to refine and evaluate the colloid models currently used in performance assessments. The LTD project consists of: a monopole diffusion experiment where weakly sorbing and non-sorbing radionuclides (3H, 22Na, 131I, 134Cs) have been circulating and diffusing into undisturbed rock matrix since June 2007; experiments to characterise pore space geometry, including determination of in-situ porosity with 14C doped MMA resin for comparison with laboratory derived data; a study of natural tracers to elucidate evidence of long-term diffusion processes; and, an investigation of the in-situ matrix diffusion paths in core material from earlier GTS experiments. Future experiments will focus on diffusion processes starting from a water-conducting feature under realistic boundary conditions.

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.

scholarly journals The Grimsel Test Site – more than 35 years of underground research

2021 ◽  
Vol 1 ◽  
pp. 239-240
Author(s):  
Andrew J. Martin ◽  
Ingo Blechschmidt
Keyword(s):  
Feasibility Studies ◽  
Field Testing ◽  
Test Site ◽  
Radioactive Waste Disposal ◽  
Diffusion Experiment ◽  
Training Centre ◽  
Barrier Materials ◽  
In Situ Experiments ◽  
Grimsel Test Site ◽  
And Migration

Abstract. Nagra and its international partners have been conducting underground research projects at the Grimsel Test Site (GTS, https://www.grimsel.com, last access: 8 November 2021) for more than 35 years. The results have been incorporated directly into modelling, safety and engineering feasibility studies necessary for the siting and construction of deep geological repositories. Various types of experiments are carried out at the GTS, each involving field testing, laboratory studies, design and modelling tasks, thus integrating all scientific aspects. Projects are typically planned over a 5 year period with the option to extend depending on the latest findings from the experiment. In the current 5 year programme (2019–2023) new phases of running in situ experiments using radionuclides were started and include the Long-Term Diffusion experiment (LTD) and the Colloid Formation and Migration project (CFM). A completely new experiment studying the migration of C-14 and I-129 in aged cement (CIM) was also initiated. Other experiments focusing mostly on engineered barrier materials were continued such as the Material Corrosion Test (MaCoTe), which is studying anaerobic corrosion of candidate canister materials in bentonite (Fig. 1). Also, a 1:1 scale experiment studying the high-temperature (>175∘C) effects on bentonite materials (HotBENT project) was started last year. In this paper we provide an overview of the CIM, LTD and MaCoTe projects, including key findings so far. In addition to research, the GTS, as part of the Grimsel Training Centre (GTC), is also used as an education platform for knowledge transfer to the next generation of scientists and engineers in the area of radioactive waste disposal and geosciences.

Radionuclide geochemistry evolution in the Long-term In-situ Test (LIT) at Grimsel Test Site (Switzerland)

2021 ◽  
pp. 127733
Author(s):  
Vanessa Montoya ◽  
Ulrich Noseck ◽  
Felix Mattick ◽  
Susan Britz ◽  
Ingo Blechschmidt ◽  
...  
Keyword(s):  
Test Site ◽  
In Situ Test ◽  
Grimsel Test Site

scholarly journals The seismo-hydro-mechanical behaviour during deep geothermal reservoir stimulations: open questions tackled in a decameter-scale in-situ stimulation experiment

2017 ◽  
Author(s):  
Florian Amann ◽  
Valentin Gischig ◽  
Keith Evans ◽  
Joseph Doetsch ◽  
Reza Jalali ◽  
...  
Keyword(s):  
Rock Mass ◽  
Geothermal Energy ◽  
Numerical Models ◽  
Test Site ◽  
Crystalline Rock ◽  
Coupled Processes ◽  
Small Scale ◽  
Intermediate Scale ◽  
Grimsel Test Site

Abstract. In this contribution we present a review of scientific research results that address seismo-hydro-mechanical coupled processes relevant for the development of a sustainable heat exchanger in low permeability crystalline rock and introduce the design of the In-situ Stimulation and Circulation (ISC) experiment at the Grimsel Test Site dedicated to study such processes under controlled conditions. The review shows that research on reservoir stimulation for deep geothermal energy exploitation has been largely based on laboratory observations, large-scale projects and numerical models. Observations of full-scale reservoir stimulations have yielded important results. However, the limited access to the reservoir and limitations in the control on the experimental conditions during deep reservoir stimulations is insufficient to resolve the details of the hydro-mechanical processes that would enhance process understanding in a way that aids future stimulation design. Small scale laboratory experiments provide a fundamental insights into various processes relevant for enhanced geothermal energy, but suffer from 1) difficulties and uncertainties in upscaling the results to the field-scale and 2) relatively homogeneous material and stress conditions that lead to an over-simplistic fracture flow and/or hydraulic fracture propagation behaviour that is not representative for a heterogeneous reservoir. Thus, there is a need for intermediate-scale hydraulic stimulation experiments with high experimental control that bridge the various scales, and for which access to the target rock mass with a comprehensive monitoring system is possible. Only few intermediate-scale hydro-shearing and hydro-fracturing experiments have recently been performed in a densely instrumented rock mass. No such measurements have been performed on faults in crystalline basement rocks. The In-situ Stimulation and Circulation (ISC) experiment currently performed in a naturally fractured and faulted crystalline rock mass at the Grimsel Test Site (Switzerland) is designed to address open research questions, which could not be investigated in the required detail so far. Two hydraulic injection phases were executed to enhance the permeability of the rock mass: a hydro-shearing phase and then a hydraulic fracturing phase. During the injection phases the rock mass deformation across fractures and within intact rock, the pore pressure distribution and propagation and the micro-seismic response were monitored at a high spatial and temporal resolution.

In situ experiments on the performance of near-field for nuclear waste repository at KURT

2012 ◽  
Vol 252 ◽  
pp. 278-288 ◽  
Author(s):  
Won-Jin Cho ◽  
Jin-Sub Kim ◽  
Changsoo Lee ◽  
Sangki Kwon ◽  
Jong-Won Choi
Keyword(s):  
Nuclear Waste ◽  
Near Field ◽  
Nuclear Waste Repository ◽  
In Situ Experiments ◽  
Waste Repository

Natural CO2 Seeps Offshore Panarea: A Test Site for Subsea CO2 Leak Detection Technology

2015 ◽  
Vol 49 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Mark Schmidt ◽  
Peter Linke ◽  
Stefan Sommer ◽  
Daniel Esser ◽  
Sergiy Cherednichenko
Keyword(s):  
Near Field ◽  
Test Site ◽  
Sensor Data ◽  
Weak Current ◽  
Volcanic Gas ◽  
Membrane Inlet Mass Spectrometry ◽  
Detection Technology ◽  
Local Current ◽  
Ground Truthing

AbstractDuring RV Poseidon cruise POS469 (May 2014), the distribution of pCO2 in the near field of submarine volcanic gas flares in shallow water depths down to 50 m below sea level was continuously monitored using three different and independent methodologies. In situ nondispersive infrared (NDIR) spectrometry, pH measurements, and onboard membrane inlet mass spectrometry (MIMS) were used to determine the fate of rising CO2 bubbles and the dissolved CO2 plume patterns in a 300 × 400-m working area. The In situ sensor carrier platform, a towed video-controlled water sampling rosette, equipped with CTD sensors, guaranteed excellent ground truthing of seafloor characteristics and bubble discharge. Sensor data and near-seafloor observations indicated that the gas bubbles (<9 mm in diameter, >97 vol.% of CO2) dissolved very rapidly within the first 10 m above seafloor. Bottom water masses enriched with pCO2 (up to 1,100 μatm) show low pH values (up to 7.80) and tend to spread rather downslope west than following the measured weak current in SSE-SSW direction. The 3-D evaluation of pCO2 plume is a valuable tool to back-trace the origin of CO2 leakage when compared with local current regimes, water column CTD data, and seafloor bathymetry. Seep sites offshore Panarea can be used for studying CO2 leakage behavior and testing measuring strategies in shallow waters. Moreover, this area is a naturally designed laboratory to improve existing physicochemical and oceanographic transport models for subsea CO2 leakage.

Building Confidence in Radionuclide Transport Models for Fractured Rock: The Nagra/JNC Radionuclide Retardation Programme

2000 ◽  
Vol 663 ◽  
Author(s):  
K. Ota ◽  
W.R. Alexander ◽  
P.A. Smith ◽  
A. Möri ◽  
B. Frieg ◽  
...  
Keyword(s):  
Fractured Rock ◽  
Test Site ◽  
Process Models ◽  
Swiss Alps ◽  
Radionuclide Transport ◽  
Transport Models ◽  
North East ◽  
Host Rocks ◽  
Experimental Technology

ABSTRACTThe joint Nagra/JNC Radionuclide Retardation Programme has now been ongoing for 15 years with the main aim of direct testing of radionuclide transport models in as realistic a manner as possible. A large programme of field, laboratory and natural analogue studies has been carried out at the Grimsel Test Site in the central Swiss Alps and the Kamaishi In Situ Test Site in north-east Japan. The understanding and modelling of both the processes and the structures influencing radionuclide transport/retardation in fractured host rocks have matured as has the experimental technology, which has contributed to develop confidence in the applicability of the underlying research models in a repository performance assessment. In this paper, the successes and set-backs of this programme are discussed as is the general approach to the thorough testing of the process models and of model assumptions. In addition, a set of key findings is presented, involving discussions on the enhancement of confidence through the program.

Sign in / Sign up

Export Citation Format

Share Document