The Grimsel Test Site National Cooperative 450 metres beneath the Juchlistock Not a laboratory in the conventional for the Disposal of The Grimsel Test Site is located at an altitude sense Radioactive Waste of 1730 metres above sea-level in the granitic Deep in the rock, the range of geological formations of the Aar Massif. It is reached via conditions found in the laboratory (frac- Hardstrasse 73 grimsel the access tunnel of the Oberhasli AG hydro- tured/water-bearing and homogeneous/ CH-5430 Wettingen power plant (KWO). The total length of the tight areas) present ideal boundary condi- Tel 056 437 11 11 laboratory tunnels is around one kilometre; tions for investigating the functioning of Fax 056 437 12 07 the tunnel network was excavated in 1983 both the geological and engineered barri- test site using a full-face boring machine and blasting ers of deep repositories. Projects that look [email protected] techniques and was extended in 1995 and at the disposal concepts on a large scale www.nagra.ch 1998. are also an important aspect of the work at www.grimsel.com the Test Site. A radiation controlled zone al- Geology lows radionuclides to be used under moni- Some 300 million years ago, magmas solidi- tored conditions, giving a direct insight into fied to form granitic rocks in the Grimsel area. the transport of radioactive substances in New molten masses flowed into fissures of the rock. the cooling rock and formed dyke rocks (lam- prophyres). During the alpine orogeny, which Internationally recognised research affected the Grimsel area around 40 million centre Innertkirchen years ago, the rocks of the Aar Massif were Today, around 25 partner organisations, as passed over by the northwards-moving alpine well as universities, research institutes research on safe nappes and subsided by around 12 kilome- and consulting companies from various Guttannen tres. The rocks were then overprinted under countries, are involved in the projects at geological disposal of high temperature and pressure conditions the Test Site. The European Union and the and shear zones and fracture systems were Swiss State Secretariat for Education and 2 km formed. Uplift (0.5 to 0.8 mm/a) and erosion Research provide financial support to sev- radioactive waste Grimsel processes, which are still continuing today, eral experiments. The work at the Test Site Test Site brought the rocks of the Aar Massif to the makes an important contribution to main- Gletsch surface once more. The mineral fractures for taining knowledge on the long term and to Grimsel- pass which the Grimsel area is famous formed transferring know-how to future genera- July 2010 Oberwald around 16 million years ago. tions. Photos: Nagra, Comet Photoshopping (Weisslingen) Visit us From June to October, Nagra offers groups the opportunity to experience free guided tours of the Grimsel Test Site. Information Renate Spitznagel Phone 056 437 12 82 [email protected] Grimsel Test Site Participating countries Deep geological disposal More than 25 years of research at the Grimsel Test Site What questions are being addressed by the work at Grimsel today? Taking responsibility Jura) – are important research centres, Focus of research to date The future What effect does the heat emitted by How are radioactive materials retained Our generation is producing radioactive both for the Swiss national programme The research activities over the last two Many repository projects will be imple- high-level waste have on the tunnel in the rock and what influences their waste and it is our duty to manage this and for international collaboration. decades have focused mainly on the mented in the 21st century and the investi- backfill and the surrounding rock? mobility? waste in a way that is both responsible following: gations in a rock laboratory prepare the The FEBEXe project is looking at the Most waste disposal concepts plan to use and sustainable. The waste producers Contribution of the rock laboratories • Developing techniques for site investi- way for this step. When planning projects, emplacement concept for high-level cementitious materials which, together Focus of current research have entrusted Nagra with implementing Rock laboratories make a key contribution and main projects gations. One example is the remote the feasibility and operational safety of waste on a 1:1 scale. The heat generated with groundwater, form high-pH solu- this important task. to answering the questions raised by safe- 1 – Processes and long-term sensing of rock formations using deep disposal are in the foreground. The by radioactive decay and the weight of tions. The flow properties and the reten- ty analyses and to confirming the feasibil- behaviour of the engineered seismic tomography. aim of the investigations in the rock labora- the waste container are simulated by an tion capacity of the rock for radioactive barriers The way to deep disposal ity of deep disposal of radioactive waste • Testing technologies for repository tory is to look at the behaviour of disposal electric heater embedded in bentonite substances can be altered by these highly FEBEXe (Full-scale HLW Building blocks of a waste In Switzerland, deep geological disposal from an engineering viewpoint. The focus Engineered Barriers construction and evaluating their systems over periods of decades under blocks. The aim of the experiment is to alkaline waters. management programme is required by law for all types of radio- of research activities includes: Experiment – extension) impact on the functioning of the repository-relevant conditions, to optimise predict the effectiveness of the engineered The LCS project is looking at the inter- 1:1 demonstration of the active waste. Experts worldwide are in • Geological and hydrogeological emplacement concept for geological barrier. Examples include technical procedures and to document barrier functions under the influence of action between the rock and such highly Laboratory studies agreement that this strategy represents characterisation of rock formations high-level waste investigating the excavation disturbed their safety. The following objectives have heat and to demonstrate their engineering alkaline waters. a safe long-term management solution. that are potentially suitable for deep FORGE (Fate of Repository zone in the rock caused by tunnel been set for the coming years: Radionuclides feasibility. The LTD project is investigating the diffu- Research projects in Field investigations for determining the disposal. Gases) Gas migration in the construction and borehole sealing • Performing experiments that demon- Each chemical element has sion of radionuclides from fractures into rock laboratories engineered barriers stable and spontaneously suitability of potential disposal sites are • Properties and long-term behaviour of (bentonite/sand) systems. strate and verify the functions of the decaying (= radioactive) What happens to gas produced in a the rock matrix, where they are partly System understanding an important component of a waste man- the components of the engineered GAST (Gas-Permeable Seal • Developing and testing the engineered engineered and geological barriers of isotopes. Radioactive waste emplacement tunnel? retained. isotopes are also called agement programme. The field work is safety barriers. Test) Gas-permeable tunnel barrier system. Besides demonstrat- a deep repository. This involves The planned GAST project is a large-scale The CFM project addresses the question sealing (planning phase) radionuclides. Conceptual models complemented by laboratory studies, • Transport and retention of radio- ing disposal concepts on a large scale, recreating the conditions that prevail sealing experiment. In a backfilled reposi- of the influence of colloids in the vicinity 2 – Radionuclide transport: Diffusion Natural analogue investigations of relevant natural proc- nuclides in the engineered barrier interactions between waste, projects have looked at the long-term in repositories over many years to The passive balancing of the tory, gases are produced by the corrosion of fractures and shear zones on the trans- studies esses (natural analogues) and research system and the surrounding engineered and geological evolution of the barriers in terms of allow slowly occurring coupled concentration of gaseous or of metals and the degradation of organic port (mobility) of radionuclides. Complex barriers dissolved substances Site-specific field projects in underground rock laborato- geosphere. saturation, heating and gas migration. processes to be better quantified. materials. How can a gas-permeable tun- in situ experiments are carried out under between areas of higher and investigations CFM (Colloid Formation and ries; these provide a better understanding • Verification of the data and models Migration) Formation and • Testing of the models and databases • Development of new technologies for lower concentration is nel sealing system be constructed without realistic boundary conditions to investi- of the safety of geological repositories, the used in safety analysis. transport of colloids and used in safety analysis. This includes the emplacement of radioactive waste termed diffusion. compromising the hydraulic tightness of gate the migration behaviour of radionu- their influence on radio- properties of suitable host rock formations • Technologies for tunnel excavation and nuclide mobility investigations of the transport and (e.g. remote handling and monitoring Colloids the system? The focus of the experiment clides