Finland opens world's first permanent nuclear waste repository

Friday 10 April 2026 - 10:40

By: Dakir Madiha

Finland opens world's first permanent nuclear waste repository

Finland nears the opening of Onkalo, the first facility worldwide built for permanent underground storage of spent nuclear fuel. After over two decades of construction, authorities expect to issue an operating license in coming months. The milestone tackles the long-standing global challenge of radioactive waste management.

Onkalo, meaning "cavity" in Finnish, sits on Olkiluoto Island off Finland's west coast near three of the nation's five nuclear reactors. Work began in 2004 on the €1 billion site, designed to bury up to 6,500 tonnes of used fuel in tunnels over 400 meters deep. Teleoperated machines in a nearby encapsulation plant will seal radioactive fuel rods in copper canisters, bedded in absorbent bentonite clay within bedrock.

The location offers geological stability and low seismic risk. "Isolation from surface civilization and populations proves crucial due to waste radiation," said Tuomas Pere, geologist at project operator Posiva Oy. Operations should run until the 2120s before final sealing.

A 2022 International Atomic Energy Agency report notes nearly 400,000 tonnes of spent fuel produced globally since the 1950s. Two-thirds remain in temporary storage. No other nation has opened a comparable permanent deep geological repository, though Canada started regulatory approval for its own.

Not everyone feels reassured. Edwin Lyman, nuclear safety director at the Union of Concerned Scientists, called geological disposal the "least bad option," with risks burdening future generations. Transmitting warnings over millennia, given waste hazards lasting hundreds of thousands of years, spawned nuclear semiotics as a field.

Finland's 1994 law mandates all domestically produced nuclear waste get managed and stored within its borders. "Some waste was exported then, but we chose to take responsibility ourselves," said Environment Minister Sari Multala. She left open accepting limited foreign waste later. Greenpeace Finland's Juha Aromaa acknowledged progress: "We may stand near a solution to this problem. No one else worldwide comes close."