Status of the Site Investigation and Site Selection Process for a Deep Geological Repository in Switzerland

Abstract

Nagra, the National Cooperative for the Disposal of Radioactive Waste, in Switzerland, is realizing a project of the century: the planning, construction, operation, and closure of a deep geological repository (DGR) for the nation’s radioactive waste. The site selection process for a DGR is regulated by a three-stage process described in the Sectoral Plan, which the Federal Government approved in 2008. An overconsolidated shale, the Opalinus Clay, was selected as the most suitable rock formation as a result of Stage 2 of the Sectoral Plan. The three remaining siting regions were investigated in detail during Stage 3, including more than 12.5 km of exploratory boreholes drilled since 2018 and high-resolution, three-dimensional seismic surveys covering an area of approximately 250 km2. In September of 2022, Nagra proposed Nördlich Lägern as the preferred siting region for a combined repository in Northern Switzerland. Nagra plans to submit the corresponding general license application to the authorities by the end of 2024.