Finland licenses world's first permanent nuclear waste repository

Overview

Updated 1 hour ago

Finland's government granted the world's first operating licence for a permanent spent-fuel repository on 22 October. The Onkalo facility, carved into 1.8-billion-year-old granite near the Olkiluoto nuclear plant, will bury Finland's used reactor fuel 430 metres underground.

The decision caps a process that ran more than 40 years. Posiva, the company running the site, still must finish commissioning tests with nuclear safety regulator STUK before the first canister goes down. Disposal is expected to continue past the 2120s, after which the tunnels get sealed.

Why it matters

Nuclear power's oldest objection is spent fuel with nowhere to go. Onkalo gives it a licensed, working solution.

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Key Indicators

6,500 tU

Licensed spent fuel capacity

The licence allows disposal of up to 6,500 tonnes of uranium across roughly 3,300 canisters.

~3,300

Disposal canisters planned

Copper-steel canisters hold the spent fuel, at a planned maximum of 60 per year.

430 m

Repository depth in bedrock

The deposition tunnels sit roughly 430 metres deep in granite that is about 1.8 billion years old.

22 years

Construction to licence

From the start of construction in 2004 to the October 2026 operating licence.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Ilkka Poikolainen

Chief executive, Posiva

Leading Posiva through commissioning toward first disposal

Petteri Tiippana

Director general, Radiation and Nuclear Safety Authority (STUK)

Overseeing final commissioning tests before disposal starts

Sari Multala

Finnish environment and climate minister

Minister who helped steer the licence decision

Organizations Involved

Posiva

Nuclear waste management company

Holder of the world's first spent-fuel disposal operating licence

Posiva is the Finnish company tasked with final disposal of spent nuclear fuel from Finland's five reactors.

Radiation and Nuclear Safety Authority (STUK)

Regulatory agency

Regulator overseeing final commissioning of Onkalo

STUK is Finland's nuclear and radiation safety regulator, responsible for verifying Onkalo's safety before disposal begins.

Teollisuuden Voima (TVO)

Nuclear power producer

Majority owner of Posiva (60%)

TVO operates the Olkiluoto nuclear power plant and owns 60% of Posiva.

Fortum

Energy company

Minority owner of Posiva (40%)

Fortum operates the Loviisa nuclear plant and owns 40% of Posiva.

Timeline

2004 October 2026

4 events Latest: 5 days ago

Tap a bar to jump to that date

October 2026
Finland grants world-first operating licence
Latest Licensing

The Finnish government grants Posiva the first ever operating licence for permanent disposal of spent nuclear fuel. Startup still needs final commissioning tests.
5 days ago
August 2026
STUK issues favourable safety assessment
Regulatory

Finland's radiation safety regulator concludes Onkalo meets safety requirements for an operating licence.
August 4th, 2026
December 2021
Posiva submits operating licence application
Regulatory

Posiva applies for an operating licence after decades of research, site investigation, and construction.
December 2021
2004
Construction begins at Onkalo
Construction

Excavation of the repository tunnels starts near the Olkiluoto nuclear plant in western Finland.
2004

Scenarios

Onkalo begins burying its first canisters

Likely Resolves by End of 2027

Discussed by: Posiva and STUK; widely anticipated in nuclear industry media (NucNet)

Posiva completes the remaining commissioning tests, STUK verifies and approves them, and the first copper-steel canister is lowered into a deposition hole. The company has given no firm date, saying only safe disposal is possible, but both sides have cleared the main regulatory hurdle.

Copper corrosion dispute delays startup

Unlikely Resolves by End of 2027

Discussed by: Greenpeace and corrosion researchers; contested by Posiva

The 2025 Greenpeace study 'Rock Solid?' argued the copper canisters' corrosion behavior under heat and radiation is not fully understood. If STUK requires additional corrosion testing or design changes before the first disposal, startup slides past 2027.

Environmental groups appeal the Onkalo licence

Possible Resolves by End of 2027

Discussed by: Environmental organizations; legal observers

Opponents of the repository could challenge the operating licence in Finland's Supreme Administrative Court. The government's decision followed a 40-year process and STUK's approval, so an appeal is possible but would need to show procedural or safety errors to suspend the licence.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

March 1999

Waste Isolation Pilot Plant, New Mexico (1999)

The United States opened the Waste Isolation Pilot Plant near Carlsbad, New Mexico, the world's first operating deep geological repository for radioactive waste. It buries transuranic military waste in salt beds hundreds of metres underground.

Then

WIPP has operated for over two decades, burying thousands of waste containers.

Now

It proved deep geological disposal can work at industrial scale, though only for less radioactive transuranic waste.

Why this matters now

WIPP validated the concept. Onkalo faces the harder test: spent fuel, far hotter and more radioactive, now goes through the same kind of program.

2002-2010

Yucca Mountain, Nevada (2002-2010)

The United States designated Yucca Mountain in Nevada as its spent-fuel repository and Congress approved it in 2002 after billions in research. Opposition from Nevada and others led the federal government to defund the project in 2010.

Then

No waste was ever buried there; the United States still has no permanent spent-fuel repository.

Now

The project showed that political opposition can kill a technically approved repository.

Why this matters now

Finland succeeded where the United States stalled, in large part by securing early acceptance from the local community in Eurajoki.

1980s-present

Sweden's KBS-3 method (1980s-present)

Sweden developed the KBS-3 method in the 1980s: spent fuel sealed in copper canisters, surrounded by bentonite clay, and buried deep in bedrock. Finland licensed the Swedish-designed technology and adapted it for Onkalo.

Then

Finland finalized the Swedish design and received its operating licence first, before Sweden's own Forsmark repository project.

Now

The adopter beat the innovator to the finish, partly by resolving political and licensing hurdles faster.

Why this matters now

The same KBS-3 technology now operates under a Finnish licence, giving Sweden and other countries a working reference case.