From a purely geological perspective, Matthias Braun, CEO of the National Cooperative for the Disposal of Radioactive Waste, finds the site for the storage of nuclear waste in Switzerland, published today, "totally boring." Nothing is supposed to move here – at least at depth – for millions of years. And for good reason.

At the press conference in Bern regarding the site selection, Nagra CEO Braun also addressed the question of whether potential earthquakes could eventually cause damage to the planned deep geological repository, offering a more nuanced perspective. He stated that tremors primarily cause damage at the surface due to seismic waves – less so at depth. The potential "threat level" is lowest at the now-preferred site near "Nördlich Lägern" between Waldshut-Tiengen and Zurich, in a layer of Opalinus Clay approximately 100 meters thick and 900 meters deep.

Radiation-safe handling. Photos: Nagra

In previous selection processes, this location near the mouth of the Aare River into the High Rhine had already been ruled out. However, experts say this was somewhat premature. The assessment has since been revised after a thorough review.

Nagra now sees itself at the end of an exceptionally comprehensive and "unique" spatial planning process, involving numerous regional authorities, committees, and expert panels for nearly 20 years. However, Nagra is only announcing today which site it intends to pursue for approval. This can only be done publicly. It will not be possible for the Federal Council and other bodies to actually grant approval before 2029.

M. Braun

Nagra CEO Braun finds it "gratifying that it is a clear decision." In the Northern Lägern region, the grey rock is 175 million years old, which is also significant from a safety perspective. Braun: "There is no further activity at that depth (...) This gives us the confidence that we can be safe for the foreseeable future.".

The Opalinus Clay is extremely dense and binds the radiation from radioactive material "practically like a magnet." Should a crack occur anywhere, the clay's composition seals the fracture, effectively "healing" the critical area automatically. This clay layer was also found at the other investigated sites. However, it is the oldest at Nördlich Lägern. Further evidence of its impermeability comes from water-bearing geological layers above the Opalinus Clay horizon. The water analyzed there is so old that fractures in past millennia can be practically ruled out.

Fig.: Nagra

From a purely logistical standpoint, it's interesting that the packaging of the radioactive material for final disposal in the deep geological repository will not take place at the same location, but rather at the existing, industrially used site near Würenlingen. Braun explains: "There are already suitable capacities, buildings, and facilities there that we can continue to use." Furthermore, he adds, in his opinion, the disposal concept would "work at all three locations." The idea for an external packaging facility originated within the region itself.

Felix Altorfer, head of the Swiss Federal Nuclear Safety Inspectorate ENSI, speaks of a minimal radiation exposure of effectively only a few microsieverts that could emanate from the nuclear waste lying deep underground.

Numerous meetings, information events, and conferences preceded the selection that has now been made. Municipalities, organizations, and delegations of international visitors had the opportunity to learn about the procedures firsthand.

M.Neukom

The positions of Green Party politicians have also changed. Martin Neukom, a member of the Zurich cantonal government and a critic of nuclear power, and president of a committee representing the cantons of Schaffhausen, Aargau, and Zurich involved in the deliberations, acknowledges: "A lot has happened in recent years." Whether it's one way or another, the Green Party figure, also a long-time member of the "Pedestrian Traffic Switzerland" initiative with 1,500 participants, believes that Switzerland must "deliver somewhere" to house and store its radioactive waste. Since this is essential, scientific work was necessary to find the best solution. The Nagra (National Cooperative for the Disposal of Radioactive Waste), often criticized, "is now much more open to controversial issues" than in the past. "They listened to us.".

All in all, the deep geological repository is expected to cost around 20 billion Swiss francs. Compensation payments to any affected parties are explicitly not referred to as "damages" for municipalities or landowners, but rather as "usage fees." Municipalities on the German side are also to be included in any payments based on potential decreases in property value.

Author: K. Koch

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