The world’s first geological grave for nuclear waste is rapidly taking shape more than 400 meters below Finnish forests.
Batches of deadly radioactive uranium will start arriving within two years to be buried in the maze of tunnels carved into the rock.
Other countries, including the UK, are planning to build their own geological storage facilities, which should safely isolate the 260,000 tonnes of highly radioactive waste that has accumulated around the world since the dawn of energy nuclear in the 1950s.
Sky News has been granted rare access to the site, called Onkalo, which means “cavity” in Finnish. It is built next to three nuclear reactors on the southwest coast of the country.
Security was so tight following the sabotage of the Nord Stream gas pipeline that there was a strict rule of no filming above ground.
But we were taken to the 5km access road that winds through bedrock, so deep our ears popped.
In the background, other tunnels have unfolded. Five have been completed so far, but up to 100 could be built over the next few decades, spanning more than 40 miles in all.
Our guide was Sanna Mustonen, geologist and senior project manager for Posiva, the company that runs the facility.
She said the bedrock was formed nearly two billion years ago and has remained untouched ever since.
“The rock itself, as in the whole region of Finlandis very stable,” she said.
“We have old rock. We don’t have continental plates nearby, so we don’t have earthquakes, seismicity or things like that.”
“There must be security”
Like other countries, Finland is storing spent nuclear fuel above ground in shielded bunkers while it seeks a long-term solution.
But Mika Pohjonen, chief executive of Posiva, said it would be irresponsible to leave such hazardous waste where it could fall into the wrong hands.
He told Sky News: “If you look at history, 300 years ago, how many wars were there in Europe, for example?
“On the surface, intermediate storage requires active measures by humans, the building has to be heated, the spent fuel has to be cooled, there has to be security around it.
“If you look a generation ahead, you can’t really see that this type of arrangement would be risk-free enough.”
Various solutions to the problem of nuclear industry waste have been suggested, including: launching it into deep space, burying it in an ocean trench, and depositing it in a crack in the earth’s crust.
They were dismissed as impractical, expensive, or environmentally hazardous.
“Safe for a Million Years”
Instead, Posiva will enclose spent nuclear fuel in double-layered metal canisters that will fit into holes drilled in the floor of the tunnels.
To keep them dry, they will be swaddled in bentonite, an absorbent material used in cat litter.
More bentonite will be used to backfill the tunnels, which will be plugged with concrete.
When the complex is full in about a century, with perhaps as many as 3,250 canisters, it will be sealed and all traces removed above ground.
“It will be safe for a million years,” Mr Pohjonen said.
“There may be no more humans here because at that time there will be ice ages or [this area will be] underwater, but this is designed to keep it out of the biosphere.”
The dummy canisters are already buried in bentonite and surrounded by sensors.
Some scientists have warned that the water could corrode the metal, become radioactive and then rise to the surface over millennia.
But Posiva says the multiple barriers keep the waste in and the water out. And if there was a leak in a highly unlikely worst-case scenario, modeling shows that by the time the water hits the surface in 10,000 years, the radioactivity would have declined so much that it wouldn’t pose a threat. for life.
Finland’s progress has been closely followed by other countries. Sweden has started construction of its own deep geological repository. France, Switzerland and the United Kingdom are even further behind.
A shortlist of four possible sites in Cumbria and Lincolnshire has been drawn up.
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Bruce Cairns, chief policy adviser at the UK’s Nuclear Waste Services, was also checking out Onkalo while we were there.
He said permanent and responsible waste disposal is essential as the country commissions a new generation of reactors.
“We have 70 years of waste in the UK that has already accumulated from power generation, defense and industrial processes.
“It’s not going anywhere unless we do something about it. We need to take steps to make sure this is managed responsibly, not just for now but for the long term as well.”
Key to Finland’s progress has been engagement with the local community.
The favorable inhabitants
The nearest settlement is Eurajoki, about 16 km away.
Existing nuclear reactors were already big local employers and when the area was selected from a shortlist of storage sites, local authorities voted overwhelmingly in favor.
Vesa Lakaniemi, the city’s mayor, said: “We’ve had nuclear power here for 40 years.
“People know nuclear and the ultimate [waste] much more storage than in regions without nuclear power plants.
“Trust has grown over four decades.”