Secrets of the deep, deep tunnels where nuclear waste is buried.

Almost half a kilometre underground, engineers in Finland are about to seal
radioactive material safely for ever. Britain wants to do the same. If all
goes to plan, spent nuclear fuel will be transported early next year down
dedicated lift shafts before robotic machines bury the 24-tonne copper and
iron canisters in the rock where they will remain for the rest of time.

This is the world’s first deep geological disposal facility for nuclear
fuel, a concept that has been discussed by engineers and politicians for
half a century. More than 20 other countries including the UK, US, France
and Sweden have plans to follow suit. But the Finns have got there first.

Fiona McEvoy, 50, the head of site characterisation and research and
development at the British government agency Nuclear Waste Services, is
here as part of a fact-finding mission to see how a similar feat could be
achieved in the UK. She says: “It’s a watershed moment for the nuclear
sector. Long-lived, dangerous waste will be locked away, safe for eternity.
That is amazing.”

Martin Walsh, 51, head of engineering at Nuclear Waste
Services, also on the visit, says: “Nobody disagrees that for the legacy
for nuclear waste in the UK, geological disposal is necessary.” The most
radioactive nuclear waste produced by Britain’s nuclear power stations will
remain hazardous, Walsh says, “beyond our lifetime, and beyond the
lifetime of our children and our children’s children”.

Burying it deep in
the earth is considered a “final disposal”, a solution that has been
calculated to enable the radioactive waste to remain undisturbed for a
nominal 500,000 years, surviving ice ages, tectonic shifts, earthquakes and
sea level rise.

The two private companies that run these facilities, TVO
and Fortum, jointly founded Posiva in 1995, developing this repository to
dispose of their waste. Every week, for the next 100 years, one canister of
spent nuclear fuel will be transported 433m down into the earth.

In the UK,
plans for a similar geological disposal scheme have experienced false
starts because no council has yet agreed to host a site. In June, the newly
elected Reform leadership of Lincolnshire county council pulled the plug on
long-running discussions to site a geological disposal site near the
coastal village of Theddlethorpe.

The most likely location for a site is
now off the Cumbrian coast, close to Sellafield. Nuclear Waste Services is
in discussions with Mid Copeland and South Copeland community partnerships
for a proposal for an access tunnel to be sunk onshore, and then run ten
miles out below the seabed, where 250 miles of disposal tunnels would be
dug, nearly ten times the size of the Finnish scheme.

Subject to local
approval and the go-ahead of whichever government is then in power,
construction is expected to start in the 2040s and start being filled in
the 2050s. It will be filled with waste for 150 years before it is sealed
in 2200.

The lifetime cost of the UK project is estimated at up to £53
billion, compared with about £5 billion for the Finnish scheme, which at
roughly a tenth of the size, serving a nation with a tenth of the
population, is roughly comparable. The speed at which progress has been
made, however, is not comparable. But Walsh defends the cautious pace the
British experts have taken. “The thought process, particularly around
nuclear, has to be robust. You have to make sure your relationship with
safety and security and the environment is sound.”

Times 28th Sept 2025,
https://www.thetimes.com/uk/environment/article/nuclear-power-waste-finland-bkq8sq0lj