Underground laboratories are used to conduct experiments in the field of repository research under natural ambient conditions.
In such underground laboratories, researchers investigate "in situ" (i.e. on the spot) the physical and chemical processes that would also take place in a repository in the host rock and in the (geotechnical) components installed there. The aim is to examine different rock formations with regard to their suitability as possible host rocks for repositories or underground disposal sites and to investigate the interaction of geotechnical components (e.g. seals) with the host rock.
Two types of underground laboratories can be distinguished: Generic underground laboratories are set up at sites that are not intended as repositories for radioactive waste. Site-specific underground laboratories, on the other hand, are by definition established at a designated repository site.