Finland is on the verge of completing the world’s first deep geological disposal facility for spent nuclear fuel, a milestone in which Britain is taking keen interest as it seeks its own permanent solution for radioactive waste, The Times UK reports.
Posiva, the company that operates the Onkalo repository beneath Olkiluoto island, is preparing to close access tunnels for final tests before the first 24-tonne copper-and-iron canisters of spent fuel are lowered into the bedrock by robotic machines. Visitors now ride Europe’s fastest passenger lift — a 433-metre descent that takes 66 seconds — to view the vast network of disposal tunnels, but next month the site will be shut to outsider access as commissioning continues.
“It’s a watershed moment for the nuclear sector,” Fiona McEvoy, head of site characterisation and R&D at Britain’s Nuclear Waste Services, told The Times UK during a fact-finding visit. British engineers say geological disposal is necessary to manage the country’s legacy waste, which will remain hazardous for generations.
Under the Finnish design, each canister will be emplaced in an 8-metre vertical hole drilled into ancient migmatite rock. Bentonite clay will be used to swell-seal the emplacement and, after centuries of operations, the access tunnels and shafts will be backfilled and permanently sealed — a process planned to conclude many decades from now. Posiva’s project timetable foresees one canister being lowered each week for the next 100 years.
Finland’s success follows more than two decades of development and local acceptance: the Olkiluoto municipal council overwhelmingly backed the plan in 2000, and national parliament supported it the following year. Posiva staff and local officials say strong public trust and long-standing community ties to the nuclear industry helped secure that consent.
For the UK, the Finnish model offers both inspiration and a cautionary tale. Britain produces far more nuclear waste and has struggled for years to site a permanent facility. Recent setbacks include the withdrawal of Lincolnshire county council from talks over a proposed geological disposal site near Theddlethorpe. The current UK plan under Nuclear Waste Services envisions an onshore access tunnel near Sellafield and a subsea repository tunnel running offshore under the Irish Sea — a scheme that, if approved locally and politically, could begin construction in the 2040s and be filled from the 2050s. The estimated lifetime cost of a UK geological disposal facility is up to £53 billion, roughly ten times the cost of the smaller Finnish scheme.
British officials emphasise caution. “The thought process, particularly around nuclear, has to be robust,” Martin Walsh, head of engineering at Nuclear Waste Services, told The Times UK. “Nobody will thank us if we get this wrong.” He and other UK visitors praised the Finnish “encapsulation plant” and the stability of 1.9-billion-year-old bedrock at Olkiluoto, noting that the rock’s hardness and long geological history are key to the repository’s design.
Posiva’s geologists and local leaders highlight the long horizon of the project: robots will operate the repository for more than a century, after which the facility will be filled and sealed — a timetable stretching into the 22nd century. For communities such as Eurajoki, where the plant has been a major employer for 50 years, the repository also represents economic continuity.
As other countries — including the US, France and Sweden — consider or advance their own geological disposal plans, Finland’s Onkalo will remain a closely watched prototype. For Britain, the path to a permanent disposal site will require securing local consent, political will and decades of careful engineering — lessons The Times UK says the UK delegation went to see firsthand.
