Repository research

Seismic measurements characterise excavation damaged zones in clay rock (Mont Terri Rock Laboratory, Switzerland). Source: BGR

The research work of the Federal Institute for Geosciences and Natural Resources substantiate the measures to provide a secure repository for low-level, intermediate-level and high-level radioactive heat-producing wastes. Such work is carried out to some extent in collaboration with other research facilities. The focal point of the work lies in the characterisation of the properties of potential host rock such as salt, clay and granite, as well as the optimisation of geotechnical barriers.

In the past, the main emphasis of the work was on salt as a host rock. Since the scientists have already gathered numerous facts on this rock, future investigations will focus on the clarification of detailed issues, the further development of constitutive laws and the systematics of the internal architectures of salt structures.

The investigations of crystalline host rocks and clay are, in contrast, not so well-advanced. This is why the Federal Institute for Geosciences and Natural Resources acquires basic data to describe these host rocks and to develop constitutive laws in order to achieve an equally high level of knowledge in this area. Since some processes not applicable to salt as a host rock arise here, new methods for laboratory and in-situ tests must be developed. Federal Institute for Geosciences and Natural Resources scientists are additionally working on instruments for modelling thermo-mechanic and hydraulic processes taking chemical reactions into account.

After the radioactive material has been stored in the repository, it has to be safely sealed up and in some areas effectively filled in. Scientists thereby design the necessary geotechnical barriers to suit the demands of the host rock in question.

The Federal Institute for Geosciences and Natural Resources makes use of intensive international collaboration in, for example, France, Sweden, Switzerland in order to plan and carry out research work in an effective and targeted way.