The Swiss repository for nuclear waste is to be built in the immediate vicinity of the German municipality of Hohentengen in Baden-Württemberg. The location was one of three possible locations. That had caused a stir in Hohentengen years ago. “Switzerland decides to leave its radioactive waste in Switzerland and almost throws it at our neighbors’ feet,” said a local councilor at a meeting in Hohentengen in 2016.

How close to the border does the repository come?

The selected area Nördlich Lägern is a few hundred meters behind the border, says the mayor of Hohentengen, Martin Benz, the German Press Agency. “The train station, which could be used for transport to and from, is a few hundred meters from our residential areas. If the nuclear waste transport comes by road: that’s also only 850 meters away.”

Why at the borders?

On the one hand, the earthquake probability must be as low as possible, on the other hand, the stone in the subsoil must have certain properties. In Switzerland, only the Opalinus Clay is suitable for storage. “The Opalinus Clay is dense, can seal any cracks itself and binds radioactive particles to itself,” said the Swiss National Cooperative for the Disposal of Radioactive Waste (Nagra). “In this way it locks in radioactive substances in the long term.” These requirements only exist in the border area.

“It is also in our interest that the Swiss waste is stored safely,” says Martin Steinebrunner from the German Coordination Office for Swiss Deep Repository (DKST) at the dpa’s Hochrhein-Lake Constance regional association. “If the safest place is a few kilometers from the border, we’ll accept that. We also have the Swiss nuclear power plants near the border. It’s a gain in safety when everything is stored.”

How much material is it?

The highly radioactive waste from nuclear power plants, medicine, industry and research totals 9,300 cubic meters. According to Nagra, this corresponds to the volume of around eight single-family houses. In addition, there is around 72,000 cubic meters of low-level and intermediate-​level radioactive waste. The four remaining Swiss nuclear power plants may be operated as long as they are safe. That may go as far as the 2040s.

How dangerous is a repository?

Radiation can destroy body cells, including those in the blood, skin and thyroid. Leukemia, thyroid and lung cancer are among the possible late effects. There are technical and natural barriers in the storage facility to prevent radioactivity from the waste from escaping. The material is embedded in uranium oxide or glass and packed in thick-walled steel containers or in drums solidified in cement. The storage tunnels are filled with bentonite or cement mortar. The tunnels are hundreds of meters deep. “The required confinement time is around 200,000 years for high-​level waste and around 30,000 years for low-level and intermediate-​level waste,” says Nagra.

What about the transportation?

It is not yet known how the material will be transported to the repository. Nagra wanted to comment on Monday. It is also unclear where the material is to be packaged for disposal. This requires a “hot cell”, a high-security building. It could be created at the interim storage facility for nuclear waste in Würenlingen, around 15 kilometers south of the German municipality of Waldshut-Tiengen.

What are the biggest concerns?

“We have drinking water fountains everywhere, we have the Aare and Rhine nearby. The question of drinking water protection is a major concern for the population,” says Steinebrunner.

When should it be built?

Nagra intends to submit a building application by 2024, which the government and parliament will decide on. Then there should be a referendum. If construction is not rejected, work is scheduled to begin in 2031. The multi-year emplacement would begin around 2050. The camp would be monitored for decades and finally sealed around 2125.

Will the German municipalities be compensated?

“When negotiating compensation payments, we want to be appropriately involved, both in the negotiations and in the outcome,” says Steinebrunner. Mayor Benz says that Hohentengen will insist that Swiss communities be given the same compensation.

How far is Germany with its search for a repository?

In Germany, 54 percent of the area is still designated as possible locations. Affects almost all federal states. The decision is also expected to be made in 2031, and the camp is also expected to start operations around 2050. Finland is furthest along, where storage in a repository for nuclear waste under the island of Olkiluoto in south-west Finland is to begin as early as the mid-1920s.