Finland nears launch of world's first permanent underground nuclear waste repository

Finland is on the cusp of opening the world's first permanent underground repository for radioactive spent nuclear fuel, a facility named Onkalo, meaning "cave" in Finnish. Blasted into 1.9 billion-year-old bedrock in Eurajoki, southwest Finland, the geological repository is nearly ready to begin operations after decades of planning and construction.

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We hope we can start the operation either at the end of this year or most probably at the beginning of next year.

Countries have grappled with the challenge of managing dangerous nuclear by-products since the 1950s, with most spent fuel currently in temporary storage. While other nations like Sweden and France are also developing final repositories, Finland is poised to be the first to launch an underground storage solution. The Finnish Radiation and Nuclear Safety Authority (STUK) is expected to issue its final assessment and approval in June, paving the way for an operating license.

"We hope we can start the operation either at the end of this year or most probably at the beginning of next year," said Philippe Bordarier, chief executive of nuclear operator Teollisuuden Voima Oyj (TVO). Spent fuel, currently cooled in water pools at an interim storage site, will be transferred to Onkalo. The facility has space for 6,500 tons of uranium, intended for spent fuel from Finland's five nuclear reactors.

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Basically, it needs to be safe forever.

Nuclear waste management company Posiva began building Onkalo in 2004, with the project's cost now estimated at one billion euros. Spent fuel will be deposited in Onkalo's tunnels for an initial 100 years, with potential extensions. The repository is designed for safe storage for at least 100,000 years, with the goal of being "safe forever." After this period, the waste's radioactivity is expected to decrease to levels comparable to natural uranium ore. The fuel will be encapsulated in corrosion-resistant copper canisters, lowered into tunnels, and sealed with bentonite clay and concrete plugs.

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So if the bentonite stays in place, we are safe.