Why do research deep underground?

Underground research offers the opportunity to study the safety functions of a disposal system under realistic conditions and to demonstrate its technical feasibility. This makes it possible to acquire the expertise needed to develop a waste repository that meets all the safety requirements.

Here are some examples of what the research involves:

• developing techniques for excavating, constructing and sealing galleries and access shafts in poorly indurated clay
• experiments to study the characteristics of the clay and understand its complex behaviour.
• investigation of the corrosion (deterioration) of potential packaging materials in contact with the clay 
• study of the migration (dispersion) of radioactive substances in the clay
• experiments to demonstrate the feasibility of disposal, on a scale comparable with a real waste repository
• acquiring instrumentation and monitoring expertise

The experiments in the underground laboratory will collect information about the characteristics of the environment in which the repository will be built, and will also provide an opportunity to observe and understand the interaction between the host rock, the waste and the engineered barriers; It is important to investigate both of these aspects deep underground because the mechanical and chemical properties of the clay are different at this depth compared to the same clay layer near the surface.