Switzerland intends to store its nuclear waste under the ground for thousands of years

After a period of relative peace and quiet, Stadel is now at the centre of a dynamic project set to last a millennium: it is to become the entrance to a massive underground disposal site for radioactive waste. The Swiss National Cooperative for the Disposal of Radioactive Waste (Nagra) spent almost 50 years looking for a site where this waste could be stored for good. In September 2022, it decided on Stadel, owing to the thick strata of stone lying deep beneath the ground there. The Opalinus clay found in Stadel offers the safest possible solution for containing radioactive substances, Nagra experts argue. The director of Nagra, Matthias Braun, said that Stadel “offered the best safety reserves” of all the locations they had examined. He conspicuously failed to mention that alongside the site being the best for geological reasons, local political resistance to the project is also low.

Switzerland began transporting its nuclear waste, sealed in concrete-filled steel barrels, across Europe via goods train in 1969 and dropped it into the North Atlantic. It kept up this controversial practice until 1983.

Thinking in unfathomable timespans

Shafts up to 900 metres in depth are to be dug into the ground near Stadel. These shafts will provide access to the caverns that will be carved out of the thick Opalinus clay and used for storing radioactive waste. Nagra has to think in terms of unfathomable timespans: according to current knowledge, low- and medium-level radioactive waste needs to be stored safely for 30,000 years. As for highly radioactive waste, Nagra is working on the assumption that it will need to be stored for around 200,000 years. The safety reserves should be designed to prevent the radioactive material being brought to the surface - by anyone or anything - for around one million years.

Nuclear semiotics: talking to distant posterity

Until then, Nagra still needs to find the answer to the question of how we can warn future societies of the dangers lurking under the ground in Stadel. It is a difficult one, as any warning signs erected today will have disappeared without a trace in 100,000 or even 10,000 years. The English megaliths Stonehenge serve as an illustration of the challenge involved: even though the impressive structure is only around 4,000 years old, its meaning and purpose have been lost to time. Researchers are therefore working on nuclear semiotics, a form of expression intended for the inhabitants of the distant future, in the knowledge that human society in its current form may no longer exist in 200,000 years, and numerous ice ages may have resulted in glaciers shearing layers off the surface of the land in Stadel and reshaping it completely.

2011 marked the decision to exit nuclear energy

Compared to all the protests against Nagra, reactions to the site it chose have been relatively mild. Even fierce opponents to the use of nuclear energy – including the Green Party and Greenpeace – admit that Switzerland has no alternative if it is to meet its responsibility and store the radioactive waste it generates as safely as possible. Another reason for this position is that Switzerland’s gradual exit from nuclear power has now been decided. In the direct aftermath of the Fukushima nuclear disaster (2011), the Swiss Federal Council voted not to approve the construction of any new nuclear power stations. The dismantling of the Mühleberg nuclear plant, commissioned in 1972, has already begun. Although the remaining four nuclear reactors of Beznau I (1969), Beznau II (1972), Gösgen (1979) and Leibstadt (1984) are still running, they are slowly but surely reaching the end of their lifespan. Against this backdrop, many see the final disposal site as an estimated 20-billion-franc final chapter in the history of nuclear energy use in Switzerland.