In the “project of the century”, the Swiss seek to bury radioactive waste
Saint-Ursanne (Switzerland) (AFP) – Storing radioactive waste on the surface is risky business, but the Swiss believe they have found the solution: burying spent nuclear fuel deep in clay.
The Mont Terri International Laboratory was built to study the effects of burying radioactive waste in clay which lies 300 meters below the surface near Saint-Ursanne in the north-west of the Jura.
The underground laboratory spans 1.2 kilometers (0.7 miles) of tunnels. Niches along the way, each about five meters high, are filled with various mock storage, containing small amounts of radioactive material monitored by thousands of sensors.
More than 170 experiments were carried out to simulate the different phases of the process – positioning the waste, sealing the tunnels, monitoring – and reproducing all the physical and chemical effects imaginable.
According to experts, it takes 200,000 years for the radioactivity of the most toxic waste to return to natural levels.
Geologist Christophe Nussbaum, who heads the lab, said the researchers wanted to determine what the possible effects might be “on the storage which is expected to last almost a million years”.
This is “the length of time we need to ensure safe containment”, he said, adding that so far “the results are positive”.
Potential sites identified
Three potential sites in the northeast, near the German border, have been identified to receive this radioactive waste.
Swiss nuclear power plant operators are expected to choose their preferred option in September.
The Swiss government is not expected to make the final decision until 2029, but that is unlikely to be the final word as the issue would likely be put to a referendum under Switzerland’s famous system of direct democracy.
Despite the slow process, environmental activists from Greenpeace say Switzerland is moving too fast.
“There are a myriad of technical issues that are unresolved,” Florian Kasser, nuclear affairs officer for the environmental activist group, told AFP.
For starters, he said, it remains to be seen whether the systems in place can “guarantee that there will be no radioactive leak in 100, 1,000 or 100,000 years.”
“We are putting the cart before the horse, because with many questions still unanswered, we are already looking for sites” to accommodate the storage facilities, he said.
Kasser said Switzerland also needs to think about how it will report where the sites are to ensure they are not forgotten and people centuries from now remain aware of the dangers.
Swiss nuclear power plants have been pumping radioactive waste for more than half a century.
Until now, it was managed by the National Cooperative for the Elimination of Radioactive Waste, or NAGRA, founded in 1972 by the operators of the power plants in collaboration with the State.
For the moment, the waste is stored in an “intermediate depot” in Wurenlingen, about fifteen kilometers from the German border.
Switzerland hopes to join an elite club of countries approaching deep geological disposal.
So far, only Finland has built a site, in granite, and Sweden gave the go-ahead in January to build its own waste nuclear fuel burial site in granite.
Next comes France, whose Cigeo project, led by the National Agency for Radioactive Waste Management (ANDRA), provides for underground storage of radioactive waste in clay.
“We are awaiting the declaration of public utility but in the meantime we will apply for a building permit,” said ANDRA spokesperson Emilie Grandidier during a visit to Mont Terri.
Following the 2011 nuclear accident at the Fukushima power plant in Japan, Switzerland decided to gradually phase out nuclear power: its reactors can continue as long as they remain safe.
According to forecasts, 83,000 cubic meters of radioactive waste, including some high-level waste, will have to be buried.
This volume corresponds to a 60-year operating life of the Beznau, Gosgen and Leibstadt nuclear power plants, and the 47 years of operation of Muhleberg before their closure in 2019.
The filling of underground tombs with nuclear waste should begin by 2060.
“This is the project of the century: we have carried out scientific research for 50 years, and we now have 50 years for the authorization and the realization of the project”, declared the spokesman of Nagra, Felix Glauser.
The monitoring period will span several decades before the site is sealed off in the 22nd century.
© 2022 AFP