It is a cold day at the beginning of summer. But 450 meters beneath the rolling hills of the Champagne region of northeastern France, Franceit’s much hotter.
The fluorescent lights in this facility are bright and the air is dry. I can taste the dust in the atmosphere. The heavy emergency masks I have to carry with me remind me of the dangers I could face at that depth.
Then I start to get disoriented for some rocky, rough, criss-crossing passageways of the underground laboratory where you can hear the hum of hidden electronic equipment and the lack of people. How do I get back to the elevator?
I turn a corner and in front of me is a huge chamber, so big that for a moment I think I’ve stumbled upon a pharaoh’s tomb. But it was not built by the ancient Egyptians.
It was excavated as a storage site for some of the most radioactive substances on Earth: medium and high level nuclear waste.
How do you design, build and operate structures that take decades to plan, even longer to build, that must survive 100,000 years, and that contain some of the most dangerous materials on the planet?
A four-hour drive east of Paris, these 2.4 km of tunnels are home to countless scientific experiments, tests of construction techniques and technological innovations.
France’s National Radioactive Waste Agency (Andra) needs to show them to regulatory bodies if it wants to obtain a license to build one. geological storage facility (GDF, for its acronym in English) next to the tunnels.
Geological storage facilities for nuclear waste are, or will be, some of the largest underground structures ever built by humanity. They are planned, in development, about to begin construction or about to be inaugurated in the United Kingdom, France, Sweden, Finland and twenty other countries.
Finland was the first country in the world to build a deep geological storage facility for spent fuel, and has already carried out the first phase of test disposal of the fuel.
In Sweden Construction is about to begin on a GDF in Forsmark, a two-hour drive north of Stockholm, and a similar facility is expected to be built relatively soon in France.
In United Kingdom A possible location for this type of storage has not yet been chosen.
“The authorization for one of these high-level waste disposal facilities It has been between 20 and 30 years“We have not seen any country that takes less time,” explains Jacques Delay, my guide and scientist at the facility in France. “And then the operation will last about 100 years before it is sealed.” Afterwards, there will be hundreds of years of surveillance of the place.
“The key to locating a GDF is finding a suitable site and a willing host community,” says Amy Shelton, senior community engagement officer at the UK Nuclear Waste Services (NWS). “But it all starts with geology. ”.
In countries across Europe, engineers like Shelton pore over the available geological data of a potential site to see if the rocks lying nearby a depth of between 500 m and 1 km They are suitable for confining nuclear waste for more than 100,000 years.
Rocks like granite and clay are the best for this. But there may simply not be enough data to make a confident decision.
A promising place may turn out to be too close to vital aquifers that supply fresh water to local communities, or on the side of a valley, which in 10,000 years may mean that it is in danger from the advance of a glacier. So the search has to start again.
In some countries it is easier than in others to find a space. “Swedish bedrock [y finlandés] It is very stable in terms of seismic activity,” says Anna Porelius, communications director at SKB, the organization that manages Sweden’s nuclear waste.
“It has been a continuous entity… for more than 900 million years. Furthermore, new fracture zones no longer form.”
Sometimes human geography is the problem. “Many of the communities that were offered were absolutely disposable, such as those that were too close to the suburbs of Paris,” says Delay. “Imagine building a nuclear waste warehouse in Harrow or Wimbledon! [en los suburbios de Londres]”.
Communities volunteer to host a GDF for reasons such as the promise of much-needed investments and well-paying jobs. Your consent is required at all times. In turn, this may depend on your experience with the nuclear industry.
In the United Kingdom, the experience has not been the best. In Finland it is a different story.
“We have been producing nuclear electricity since the late 1970s,” says Pasi Tuohimaa of Posiva Oy, the Finnish nuclear waste disposal company. “People know the safety culture; They have relatives and neighbors who have worked on the site. So they understand the waste thing.”
If done wrong, Protests can break out quickly “During the process in Sweden, SKB learned valuable lessons about the importance of a positive response to its plans from the local population,” says Porelius.
“There were protests in several places and in Almunge… against drilling [de prueba] the SKB”.
Given the problems in finding a site, it may seem easier – and cheaper – to store this nuclear waste in a disused mine, as Germany did in the 1960s and 1970s with its low-level radioactive waste.
“It’s a perfectly understandable and natural question: ‘Well, we have these places, why don’t we reuse them?’” says Neil Hyatt, chief scientist at the NWS. “But they have not been built with our purpose, nor in the long term, nor with nuclear security in mind.”
Certainly, the mines were not built with the precision necessary for the storage of high-level nuclear waste. “The ramp to the bottom of the reservoir is estimated to take… five years to complete,” Porelius says. “It’s a long time compared to traditional mining operations.”
If a GDF is built where there are still mineral resources to be exploited, the chances of the “nuclear sarcophagus” being disturbed in the future increase, regardless of whether or not there is current mining activity.
The last tin mine closed in Cornwall, England, in 1998, but 26 years later Cornish Lithium plans to extract lithium from the historic mining district due to demand for electric vehicles.
It might also be easier to build a new nuclear waste facility.
“In Finland we are used to building underground to escape the elements,” says Tuohimaa. “Building a new facility allows us to plan the entire site from scratch.”
French engineers have built a funicular for a 4 km (2.5 mile) ramp to demonstrate the safety features needed to stop a container from falling out of control.
They have also shown that there is technology, such as autonomous robot dogs from Boston Dynamics, which could “be used without any human intervention to move waste drums knocked out of place by an unexpected event such as an earthquake,” explains Delay.
Engineers have even developed a robot to “recover a drum from a corroded cell” crawling through the long, narrow and claustrophobic tunnels that will contain high-level nuclear waste. Your job will be to remove any obstructions and make the barrels safe.
In Sweden, plans are more advanced. According to Porelius, “sometime in the 2080s, the repository will have something like 60 km of tunnels with space for more than 6,000 copper drums of spent nuclear fuel… The repository of nuclear waste will be done with machines designed as they can be handled remotely with great precision.”
“Magne is an example of a prototype machine that we have built,” he adds. “The machine will be used to place copper drums into deposition holes 500m deep in the bedrock.”
But technology rarely evolves as we expect. “It would be absurd to think that current technology can be relied upon in a facility with the timelines of a GDF,” Hyatt says. “That is why facilities must be designed so that they can be repaired, updated, replaced and resistant.”
GDF designers must contend with one more complication: the principle of recoverability. In France, the law requires that any waste deposited at the GDF during its operational phase can be safely recovered. In the UK, this is more of a general guiding principle.
But the recovery process becomes progressively more difficult as each chamber is sealed, until the entire facility is sealed forever.
Others are more optimistic. “We are burying spent fuel forever, but there is also reversibility,” Tuohimaa says. “When it’s sealed, it’s sealed… but the world may look very different in 100 years.”
For Delay, “when it is sealed it is a question of society, not of the technicians.”
After all, timelines are difficult to understand when it comes to nuclear storage, and these projects will take hundreds of years to complete. So, what motivates these in-demand specialists today to work on a project that they will probably never see completed?
“For most of us it is a sense of purpose.”say Porelius.
“None of us may see the final repository project completed, but what we do now and how well we execute the nuclear waste solution affects generations to come. Doing it well… gives us the motivation to keep going”.