In close to 40 years of operation at the Grimsel Test Site (GTS), a wide range of investigations have been carried out in many fields, including geology, geophysics, hydrogeology, rock mechanics and nuclide transport. The scientific work performed has been already shown to over 50,000 visitors and has been presented in many papers presented at conferences or published in scientific journals and the technical reports. Phases I - IV ran from 1984 - 1996.
Grimsel Phase V ran from 1997 to 2004. The focus was on investigating geological barrier effectiveness, demonstration of disposal concepts and site characterisation investigations. All the projects were also designed to contribute to the further development of and assessment of modelling capabilities.
Phase V saw the construction of new caverns at the GTS and experience gained in the use of radionuclide tracers was built on during the investigations of the geological barrier. GTS phase V can be grouped into three main areas of interest.
The Engineered Barrier System: FEBEX, GMT and FOM
Processes in the Geological Barrier: HPF, CRR and GAM
Site Characterisation and Modelling: EFP and CTN projects
CRR Project
The CRR experiment aimed to improve understanding of the in situ retardation of colloid-associated, safety-relevant radionuclides in the vicinity of an engineered barrier/host rock interface.
EFP Project
The EFP project examined the method for characterising the rock mass and for developing a structural model.
Febex Project
FEBEX demonstrated the feasibility of actually manufacturing and assembling an engineered barrier system.
FOM Project
FOM developed the technology for installing fibre optic sensors in an engineered barrier material, like bentonite or bentonite-sand mixtures, and demonstrated the operation of the system under relevant in-situ conditions.
GAM Project
GAM investigated the behaviour of gas in the far field (geosphere) surrounding a radioactive waste repository.
GMT Project
GMT explored how the gas migration through the Engineered Barrier System (EBS) would influence its integrity.
HPF Project
HPF assessed the potential perturbations of a hyperalkaline plume on a repository host rock under realistic, in-situ conditions