Deep boreholes in Bözberg completed, Nagra to investigate underground in Stadel next

The two deep boreholes in the community of Bözberg have been completed, the next two will be drilled in the community of Stadel.

The National Cooperative for the Disposal of Radioactive Waste (Nagra) drilled two boreholes in the community of Bözberg. The first one in Ursprung was completed in early December and the second one in Riedacker on 14th December. The borehole investigations focus on the Opalinus Clay host rock in which the deep geological repository will eventually be constructed, in particular on its thickness, tightness and composition.

Philipp Senn, Nagra’s Deputy Head Collaboration Sectoral Plan and Public Outreach, is pleased with the results of the Bözberg boreholes. “During the entire drilling procedure, we were able to recover good rock samples that are now being investigated in laboratories. Despite working conditions having become more difficult due to the coronavirus, we were able to continue without any noteworthy incidents or delays.”

Jura Ost also suitable for a deep geological repository

With these two boreholes, Nagra expects to have completed its geological investigations in the Jura Ost siting region. “Together with the data available from an earlier borehole in the community of Riniken, we now have sufficient knowledge of the underground in the Jura Ost region”, Philipp Senn explains. “Initial results confirm that this region is also suitable for hosting a deep geological repository. At the moment, we believe that we will not need another borehole there.”

Nagra will next be investigating the underground of the community of Stadel in the Nördlich Lägern region. As of 18th December, drilling started in the Hasliboden area of the Stadel community (Stadel-3) and will continue over the upcoming holidays.

Another borehole is scheduled to start in Steinacker (Stadel-2) in January. Nagra already drilled a deep borehole in Bülach in the Nördlich Lägern region in 2019. During this procedure, scientists discovered a fossilised coral reef above the Opalinus Clay. “In Hasliboden, we will drill through the reef again, but Stadel-2 is located to the west of it. This allows us to complete the picture of the underground in Nördlich Lägern”, Senn clarifies.

Drilling a borehole takes six to nine months and, for technical reasons, work is conducted around the clock. “We are making an effort to minimise emissions such as noise, traffic and light”, says Senn. “We work with electrically operated drilling equipment which is much quieter. Where necessary, as for example in Stadel-2, we also erect noise barriers.” Nagra has set up a hotline for questions and concerns of local residents and other interested persons. It operates 24/7 and is free (0800 437 333). Nagra wants to use the results from the deep boreholes to determine which of the three potential siting regions is best suited for a deep geological repository. The lead in the search for a site lies with the Federal Government.

Further information: Felix Glauser, Nagra’s Media Office, 056 437 12 26,

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.