Finland grants permit for Onkalo permanent underground nuclear repository
Onkalo, after 22 years of work and at an estimated cost of 1.16 billion dollars, received a permit on 22 October 2026 to store spent fuel deep underground.
Finland has become the first country in the world to receive a permit for the permanent, deep geological storage of spent nuclear fuel. The facility, known as Onkalo, reached this milestone after 22 years of development and carries an estimated price tag of 1.16 billion dollars.
What the permit allows and where the repository sits
The repository is located more than 400 metres underground in ancient bedrock formations that are nearly two billion years old. It is designed to hold up to 6,500 tonnes of spent nuclear fuel, each batch sealed inside specialized copper canisters intended to isolate the material for very long periods.
Posiva, the company overseeing the project, says the waste will remain isolated for tens of thousands of years and that after about 100,000 years its radioactivity is expected to approach the level of natural uranium ore. The Finnish government issued the construction and operation permit on 22 October 2026.
Although the permit marks a historic step for the nuclear industry, additional safety checks must be completed before final operations begin. Authorities and project managers say the site could serve as a technical model for other countries investing in nuclear energy, and it may create opportunities for firms developing long-term radioactive waste management technologies.
The Onkalo project has been closely watched internationally as a test case for how to store high-level radioactive waste safely over geological timescales. With the permit now granted, work will proceed toward completing remaining regulatory and technical verifications.
Photo: press material from the event
