Finland licenses Posiva's spent-fuel repository

Finland has granted Posiva Oy an operating licence for its spent-fuel encapsulation plant and final disposal facility at Olkiluoto, authorizing disposal of up to 6,500 tonnes of uranium through 2070. The decision clears a major regulatory step for the world’s first licensed deep geological repository, but it does not mean disposal starts immediately: the Finnish regulator must still complete a pre-operation inspection.

Key facts

• The Finnish Government granted the licence on 22 October 2026.
• The facility may handle up to 6,500 tonnes of uranium in spent fuel from the Olkiluoto and Loviisa nuclear power plants.
• The licence runs to the end of 2070.
• The underground repository, Onkalo, is built at more than 400 metres depth.
• Posiva cannot start operating until STUK completes its statutory pre-operation inspection.

What happened

The Government’s decision authorizes Posiva to encapsulate and permanently dispose of spent nuclear fuel generated by Finland’s Olkiluoto and Loviisa power plants. The facility combines an above-ground encapsulation plant with Onkalo, the underground disposal repository. The licence covers a maximum of 6,500 tonnes of uranium in spent fuel, equivalent to about 3,300 disposal canisters.

The authorization is valid through the end of 2070. Posiva’s plan, once operations are fully established, is to dispose of no more than 60 canisters a year. The government estimates that disposal will continue into the 2120s, after which the repository would be backfilled and closed. These are operating plans, not a fixed annual production schedule or a guarantee of a particular start date.

The licence also sets limits for other waste generated by the facility and its owners’ nuclear operations. Posiva may handle up to 3,000 cubic metres of low- and intermediate-level waste, with no more than 1,500 cubic metres designated for final disposal. The decision allows limited disposal of certain other radioactive waste produced in Finland, including some waste from healthcare and research institutions.

Why it matters

The licence moves Finland’s long-running repository project from construction and regulatory review into the operating-authorization phase. It is the first operating licence issued for a deep geological facility intended for spent nuclear fuel, but the practical distinction matters: licensing the facility is not the same as accepting the first canister underground.

The Radiation and Nuclear Safety Authority (STUK) must inspect the facility under section 20 of Finland’s Nuclear Energy Act before Posiva can operate it. STUK continues to supervise completion of commissioning and may require corrective measures. The regulator’s own reporting describes open commissioning work and conditions that must be met before operation, so the inspection and evidence of readiness remain decisive steps rather than formalities.

The licence also imposes ongoing safety documentation requirements. Posiva must submit a periodic safety assessment and updated long-term safety justification within 10 years of the licence being granted, then repeat safety assessments during operations under Finnish nuclear legislation. The facility’s owners, Teollisuuden Voima and Fortum, must ensure the project has sufficient financial resources.

Background

Posiva is owned by Teollisuuden Voima Oyj and Fortum Power and Heat Oy, the companies behind Finland’s Olkiluoto and Loviisa nuclear plants. Its system is designed to place spent fuel in disposal canisters and isolate it in the deep geological repository. The government describes the repository as more than 400 metres underground; the licence covers the fuel produced by Finland’s currently operating nuclear power plants.

STUK’s review preceded the government decision. The regulator submitted a favourable statement on 4 August 2026, after reviewing the licence application and its safety case. That favourable assessment enabled the government to grant the licence, while leaving STUK with oversight of commissioning and the final pre-operation inspection.

NNN has followed related fuel-management issues in its coverage of Norway’s agreement for legacy research-reactor fuel and spent-fuel-pool water levels at Zaporizhzhia. Those cases differ from Finland’s permanent-disposal project, but each shows that spent fuel remains a safety and logistics responsibility after it leaves a reactor. More NNN reporting is collected under the waste and decommissioning topic hub.

What's next

STUK’s pre-operation inspection is the immediate gate. Posiva must demonstrate that the facility and its systems meet the conditions for safe operation; the government’s licence alone does not authorize startup before that inspection is complete. Once operations begin, the next measurable milestones will be the commissioning decision, the first fuel canisters accepted for encapsulation and disposal, and the pace at which the facility approaches its planned annual limit.

The long-term obligation extends beyond the operating licence. Finland’s decision says the state will assume responsibility for the spent fuel after the repository is closed, while Posiva must preserve the information needed for that transfer. For now, the concrete change is regulatory: the project has permission to operate, subject to the regulator’s final readiness check.