Further details on the additional information required by ENSI (Swiss Federal Nuclear Safety Inspectorate) on the indicator «Depth with respect to engineering feasibility» were made available to Nagra (National Cooperative for the Disposal of Radioactive Waste) in November. Preparing the additional documentation will take around half a year. ENSI’s request relates to one specific indicator out of a total of 40, namely the aspect of optimising the repository depth in terms of safety. This is of particular relevance for deciding whether the very deep siting region Nördlich Lägern should undergo further investigation in Stage 3 of the Sectoral Plan process. «As before, Nagra is convinced that a repository can be constructed safely at a depth of 900 metres, but believes that this greater depth has disadvantages in terms of safety compared to a depth of 700 metres», explains Markus Fritschi, a Member of Nagra’s Executive Board.
If – as is possible in an unbiased and open process - a review of the complete documentation leads ENSI to reach a different conclusion to Nagra, namely that Nördlich Lägern should undergo further investigation, this would result in a further delay of around 2 years in the waste disposal time plan. «To be prepared for every eventuality and avoid potential delays, we have decided to start with planning the investigations for the Nördlich Lägern siting region», explains Fritschi. In concrete terms, this means preparing an exploration concept for Stage 3 and planning a 3D seismic campaign, as well as deciding on potential sites for deep boreholes.
According to Swiss nuclear energy legislation, the producers of radioactive waste are responsible for its safe management and disposal. In 1972, the nuclear power plant operators and the Federal Government set up the National Cooperative for the Disposal of Radioactive Waste (Nagra) to perform this task. Nagra, which has its headquarters in Wettingen (AG), is the national technical competence centre in the field of deep geological disposal of radioactive waste.
Out of a strong sense of responsibility for the long-term protection of man and the environment, 110 employees are involved daily in performing this important work. The high level of competence is secured by targeted research programmes in two Swiss underground rock laboratories and intensive international collaboration.