When nuclear energy was first used for peaceful purposes in Switzerland, the construction of deep geological repositories required to manage the radioactive waste was still a distant prospect. At an early stage, however, the legislator wanted to make sure that the subsequent management of Swiss nuclear waste would be possible. In the Federal Resolution concerning the Federal Act on the Peaceful Use of Atomic Energy (Atomic Energy Act) dated 6 October 1978, the legislator stated that a general licence for a new nuclear power plant would be issued only if permanent and safe management and final storage of the radioactive waste originating from the plant is guaranteed. These provisions were also extended to existing nuclear power plants. The operators of the nuclear power plants then commissioned NAGRA (the National Cooperative for the Disposal of Radioactive Waste) to draft the proof of waste management that was required. This led to the “Projekt Gewähr 1985” (“1985 Guarantee Project”).
In order to furnish proof of waste management, it had be shown on the basis of a feasibility study that safe storage of radioactive waste would be possible in deep geological repositories in Switzerland. At this stage, however, the project was not one that would be effectively carried out at a specific location. The proof in this context is fundamental in nature, and it must be based on geological data obtained from soundings and probes.
Under the auspices of “Projekt Gewähr 1985”, NAGRA submitted proof of waste management for L/ILW at the “Oberbauenstock” site, which was then reviewed and approved by the Federal government’s safety authority (then known as the HSK, Hauptabteilung für die Sicherheit der Kernanlagen, Principal Nuclear Safety Division) (HSK expert report on “Projekt Gewähr 1985”, german, PDF, 2 MB). In 1988, the Federal Council accepted that this proof of waste management for L/ILW had been furnished.
For HLW, NAGRA simultaneously submitted proof of waste management in the crystalline rock of northern Switzerland. In its expert report, the HSK arrived at positive conclusions concerning the safety and feasibility issues. However, it took the view that the question of a site was still open. The HSK assessed the search for a suitable site in the crystalline basement of northern Switzerland as a difficult and costly undertaking which offered no guarantee of success.
The Federal Council endorsed this verdict in its decision on “Projekt Gewähr” and requested NAGRA to extend its investigations to sedimentary rock formations. Since 1988, NAGRA has therefore focused its work on sedimentary rock formations, and has carried out an extensive programme of sediment examinations. In 2002, NAGRA submitted proof of waste management for a deep HLW geological repository in the Opalinus clay of the Zurich Weinland region. The Federal Council approved the proof of waste management for HLW that was submitted by NAGRA on the basis of the HSK’s expert report, together with comments by commissions and experts. The Federal Council therefore confirmed that, in principle, it is possible to manage all the radioactive waste in Switzerland.