Feasibility of safe deep disposal of high-level waste in Switzerland confirmed

Nagra’s technical reports on the Entsorgungsnachweis project were published in 2002; the project is based on the example of the Opalinus Clay in the region of the Zürcher Weinland. Following a regional field investigation programme and a broadly based selection procedure, the rock type and the investigation area on which the project was to be based were selected in 1994 with the approval of the federal authorities. The scientific results show that the Opalinus Clay in the Zürcher Weinland is suitable as a host rock for construction of a deep repository for high-level waste and that such a facility would meet official protection objectives and criteria. At the end of 2002, Nagra therefore requested the Federal Council to approve the Entsorgungsnachweis project.

Between 2003 and 2005, the technical documentation was reviewed by the federal safety authorities, with positive results: the Federal Nuclear Safety Inspectorate (HSK), the Commission for Nuclear Waste Management (KNE) and the Federal Commission for the Safety of Nuclear Installations (KSA) – as well as international experts of the Nuclear Energy Agency (NEA) – all gave the project high marks. This was echoed by the German group AkEnd (working group on selection procedures for repository sites), which also gave the Swiss selection procedure its approval.

Significance of the decision

The Nuclear Energy Act calls for a demonstration of safe disposal of radioactive waste. With the approval of the Entsorgungsnachweis project by the Federal Council, an important milestone in the Swiss waste management programme has been reached. Nagra welcomes the decision of the Federal Council and considers it to be a sign of confidence in its research work, which has extended over more than 30 years.

Site selection procedure

In 2002, Nagra also requested the Federal Council to agree to focusing further investigations in the high-level waste programme on the Opalinus Clay in the potential siting area of the Zürcher Weinland. Despite the positive review of the Entsorgungsnachweis project, the Federal Council has rejected this request and, in the meantime, has decided to implement the sectoral plan procedure. In this open procedure involving the Cantons, neighbouring countries and the public, possible alternatives will be investigated before a site is finally selected.