The impact of future glacigenic erosion on the minimum depth of a radioactive waste repository
Country / Region: Germany
Begin of project: August 1, 2021
End of project: January 31, 2023
Status of project: September 22, 2023
View of a 3D model of the base of the Quaternary in northern Germany. The deepest parts of the tunnel valleys are located approximately 200 m below the surface
Source: BGR
The Site Selection Act (StandAG) requires a minimum depth of the upper boundary of the isolation-rock zone of 300 m below the ground surface for a radioactive waste repository. However, depending on the location a depth 300 metres may be insufficient to safeguard the isolation-rock zone against damage due to future geological processes. Glacigenic erosion, such as tunnel-valley formation, has a major impact on the required minimum depth of an isolation-rock zone (cf., § 23 para. 5 no. 3 StandAG ).
Subglacial erosion during potential future glaciations is a major challenge for the long-term safety of a repository in deep geological formations. Pleistocene subglacial erosional structures may provide information on the dimensions and distribution of future glacigenic erosional structures.
The aim of this new project is to recommend a minimum depth of the upper boundary of the isolation-rock zone (300 m or deeper), considering potential future subglacial erosion, especially tunnel-valley formation. The project was assigned by the Federal Company for Radioactive Waste Disposal (BGE) after successful application of the Federal Institute of Geosciences and Natural Resources (BGR) on a public announcement.
The state-owned company for geologic repositories, the Bundesgesellschaft für Endlagerung mbH (BGE), and the Federal Institute for Geosciences and Natural Resources (BGR), conducted a virtual workshop on “Tunnel valleys” from 9.-10.12.2021.
Download: Pleistozäne subglaziale Rinnen: Tiefe, Verbreitung und Bedeutung für die Mindesttiefe eines Endlagers (2023) (PDF, 36 MB)