Nagra plans a third borehole in the Nördlich Lägern siting region

Nagra is planning a third borehole in the Nördlich Lägern siting region. The first borehole in Bülach has been completed, and the second and third ones will be conducted in the community of Stadel.

The Bülach borehole was the first in the Nördlich Lägern siting region and was successfully completed at the end of 2019. Drilling of the second borehole (in the Hasliboden area of the Stadel community) will begin in the second half of the year. Nagra expects to start drilling a third borehole in Nördlich Lägern in the Steinacher area of the Stadel community by the end of 2020.

The Bülach borehole confirmed that Nördlich Lägern is also suitable in principle for the construction of a deep geological repository. The Opalinus Clay in which the repository will eventually be constructed is over 100 metres thick in Bülach and very tight.

Drilling outside the coral reef

“In the Bülach borehole, we drilled through a coral reef located above the Opalinus Clay. We will penetrate this limestone layer again in the Stadel borehole in Hasliboden. We are now interested in the underground environment outside this coral reef”, states Maurus Alig, a member of Nagra’s Executive Board and Major Project Coordinator for Stage 3 of the Sectoral Plan. “Three years ago, we conducted seismic measurements. The resulting images are comparable to those of ultrasound, and we were able to identify the reef’s margin. It runs from north to south and passes straight through the Stadel community. For this reason, we will now drill to the west of the coral reef”, Alig explains. Nagra’s goal is to further complete the picture of the underground in the Nördlich Lägern siting region, and the borehole in the Steinacher area is expected to provide important data.

For technical reasons, the drilling work is conducted around the clock. “We are making an effort to minimise emissions such as noise, traffic and light”, says Alig, “for example, we work with electrically operated drilling equipment which is much quieter”. Nagra has set up a hotline for questions and concerns of local residents and other interested persons. It is free and operates 24/7 (0800 437 333).

The Federal Government has the lead in the site selection process for a deep geological repository. Based on previously conducted investigations, the regions Jura Ost, Nördlich Lägern and Zürich Nordost have already been identified as being suitable for the construction of a repository. Nagra wants to use the results from the deep boreholes not only to determine which of the three regions is best suited, but also to further narrow down which areas within the siting regions are most suitable. It is not yet possible to make any statements as to which these might be.

Nagra has submitted a total of 23 permit applications for deep boreholes in the Jura Ost, Nördlich Lägern and Zürich Nordost siting regions but has since withdrawn two of them. To date, 17 legally valid permits have been granted. How many boreholes will actually have to be drilled in order to complete the overall geological picture depends on the results of ongoing work, but it is not planned to drill all the boreholes. There is an information centre at every drill site but these must remain closed during the coronavirus pandemic. Once this extraordinary situation has ended, Nagra will again offer guided tours of the drill site.

Further information: Patrick Studer, Head of Nagra’s Media Office: 076 579 36 50.

According to Swiss nuclear energy legislation, the producers of radioactive waste are responsible for its safe management and disposal. In 1972, the Federal Government and the nuclear power plant operators 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, 130 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.