“We are ready for Stage 3”


The Federal Council announced its decision in Bern today on Stage 2 of the Sectoral Plan for Deep Geological Repositories. The Federal Council has decided that, in Stage 3 of the process, Nagra should continue its investigations in the three potential siting regions Jura Ost, Nördlich Lägern and Zürich Nordost.

“We welcome this decision and are well prepared for Stage 3”, said Thomas Ernst, Nagra’s Chief Executive Officer: “We will start a series of deep boreholes in January next year, which will complete the overall picture of the underground geological environment in the three siting regions”. The borehole investigations will focus on the thickness, permeability and composition of the Opalinus Clay host rock in which the repository will eventually be constructed.

In preparation for Stage 3, Nagra has already conducted 3D seismic measurements which reveal the underground stratification of the rock layers in the three regions – the measurements can be compared to ultrasound images. In addition, Nagra has been conducting so-called Quaternary borehole investigations since March of this year. As opposed to deep boreholes which can reach a depth of one to two kilometres, Quaternary boreholes are drilled down to a depth of several dozen to a few hundred metres. They help to understand how glaciers shaped our landscape in the past and how they might also alter it in the future. This makes it possible to decide at what depth a repository must be constructed to protect it from glacial erosion processes.

“Based on the overall understanding of the underground environment and safety-related considerations, we will be able to announce in three to four years which siting regions we consider to be suitable for the construction of the deep geological repositories”, explained Ernst. Nagra will then prepare the general licence application and expects to submit it by 2024.

Sectoral Plan for Deep Geological Repositories

When realising important infrastructure projects such as deep geological repositories, the interests of the various affected parties must be taken into consideration. In Switzerland, the site selection process is defined in the Sectoral Plan for Deep Geological Repositories. This three-stage process was initiated in 2008 and is under the lead of the Swiss Federal Office of Energy. Starting its search with a blank map of Switzerland, Nagra identified six potential siting regions in Stage 1. In Stage 2, which has now been concluded, the number of regions was further reduced to three. In the third and final stage, the best sites out of the three remaining regions will be determined – either for separate repositories for low- and intermediate-level waste and for high-level waste, or for a combined repository. Nagra will submit the corresponding general licence application. After the responsible federal authorities have reviewed the application and held a public consultation phase, first the Federal Council followed by the Federal Assembly (Parliament) will decide on granting of the licence. A decision is expected around the year 2030 and is subject to an optional national referendum. The repository for low- and intermediate-level waste is planned to be in operation by 2050 and that for high-level waste by 2060.