Finland has granted an operating licence to Posiva for its spent nuclear fuel encapsulation and final disposal facility at Olkiluoto, marking the first time a deep geological repository for spent nuclear fuel has received an operating licence anywhere in the world.
Posiva said the licence allows it to move towards the operational phase of the facility, but does not authorise the immediate start of disposal activities.
Before operations can begin, the company must complete the remaining commissioning tests and inspections, which will require verification and approval by Finland's Radiation and Nuclear Safety Authority (Stuk).
Posiva said it was not providing a detailed timetable for the start of disposal operations.
The government decision follows a favourable safety assessment issued by Stuk on 4 August 2026, which concluded that Posiva's encapsulation plant and disposal facility met the safety requirements necessary for an operating licence.
The regulator said at the time that there were no nuclear or radiation safety obstacles to granting the licence, although further regulatory oversight and inspections would be required before the facility could begin operating.
Repository 430 Metres Underground
The disposal facility, known as Onkalo, is located at Olkiluoto in Eurajoki, western Finland, and is designed for the permanent disposal of spent nuclear fuel from the Olkiluoto and Loviisa nuclear power stations.
The project comprises an above-ground encapsulation plant and a deep geological repository excavated approximately 430 metres into the bedrock.
Spent nuclear fuel will be sealed in disposal canisters and placed in deposition holes surrounded by bentonite clay, with the surrounding bedrock providing an additional barrier.
Posiva said the facility is expected to operate for more than 100 years as spent fuel from its owners' nuclear power plants is transferred from interim storage to permanent disposal.
The company submitted its operating licence application in December 2021. The application followed decades of research, site investigations and construction work aimed at developing a permanent disposal solution for Finland's spent nuclear fuel.
According to the Finnish government, Posiva’s licence allows it to possess, process, store and dispose of a maximum of 6,500 uranium tonnes (tU) of spent nuclear fuel generated by the Olkiluoto and Loviisa nuclear power plants.
The government said that the licence permits the final disposal for low-level and intermediate-level waste and certain other radioactive waste and nuclear materials generated in Finland to a limited extent.
The amount of spent nuclear fuel to be disposed of corresponds to approximately 3,300 disposal canisters, the government said, adding that the plan is to dispose of a maximum of 60 canisters per year at the plant.
The final disposal operations are estimated to continue until the 2120s, after which the repository will be backfilled and closed.
Posiva a private company jointly owned by Finland’s two nuclear power producers: Teollisuuden Voima Oyj (TVO), which owns 60%, and Fortum Power and Heat Oy, which owns 40%. The companies are responsible by law for final disposal.
“This is a great and historic day for both Posiva and Finland,” said Posiva CEO Ilkka Poikolainen.
“As a result of more than 40 years of systematic efforts, Finland will launch the first final disposal facility for spent nuclear fuel in the world,” said minister of climate and the environment Sari Multala.
