The Radiation and Nuclear Safety Authority supports the licence for a spent nuclear fuel final disposal facility | Säteilyturvakeskus STUK

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The Radiation and Nuclear Safety Authority supports the licence for a spent nuclear fuel final disposal facility

Publication date<br>4.8.2026<br>10.00

Type:Press release

On 4 August 2026, the Radiation and Nuclear Safety Authority issued a statement to the Ministry of Economic Affairs and Employment on Posiva Oy’s application for a licence to operate a spent nuclear fuel encapsulation and final disposal facility. According to STUK, the safety requirements required for granting the operating licence are met. This is the first time in the world that the geological final disposal facility for spent nuclear fuel has progressed to the operating licence phase.<br>In its statement, the Radiation and Nuclear Safety Authority (STUK) states that the encapsulation and final disposal facility for spent nuclear fuel Posiva built in Olkiluoto, Eurajoki meets the safety requirements set for it in the Nuclear Energy Act and Decree. Therefore, there is no obstacle to granting the facility an operating licence with regard to radiation and nuclear safety.<br>"This is a significant step in the final disposal of spent nuclear fuel that has been prepared for more than 40 years. STUK has been assessing and overseeing the safety of final disposal over several decades. Based on the overall assessment we have now made, we can conclude that the safety requirements for granting the operating permit are met," says Petteri Tiippana , STUK’s Director General.<br>The Government decides on whether to grant the operating licence for the final disposal facility based on preparatory work by the Ministry of Economic Affairs and Employment. STUK’s favourable statement is a prerequisite for granting the operating licence. Even if the Government was to grant the operating licence, final disposal cannot yet be started. Before commencing operations, STUK shall confirm in a separate decision that the encapsulation and final disposal facility meets all safety requirements set for the start of operation.<br>In the final disposal solution selected by Posiva, the high-level spent nuclear fuel is enclosed in final disposal canisters in an above-ground encapsulation plant. The canisters will then be permanently placed in a final disposal facility built in the bedrock at a depth of 400–450 metres. The spent nuclear fuel is thus isolated from people and the living environment by several complementary release barriers. These include the final disposal canister made of iron and copper, the surrounding bentonite clay and the bedrock itself.<br>"The safety of final disposal is not dependent on a single structure or material. The safety is based on a combination of a canister, bentonite clay and bedrock, which prevents and slows down the release and migration of radioactive substances into the environment," says Jaakko Leino , Director of Nuclear Waste and Regulation.<br>Posiva is currently applying for an operating licence until the end of 2070. STUK will also monitor Posiva’s operations during the facility’s operation pursuant to the Nuclear Energy Act.<br>The safety assessment also covers long-term safety<br>In the safety assessment, STUK has examined both the safety of the encapsulation and final disposal facility during the operation phase and the long-term safety of the final disposal. The long-term safety assessment examines the development of the final disposal system and its environment over very long periods of time and how the release and transmission of radioactive substances into the environment is prevented and slowed down. In addition, STUK has assessed the readiness of Posiva’s organisation to start operation of the encapsulation and final disposal facility.<br>STUK’s statement is based on a long and thorough safety assessment. "Demonstrating safety has been the starting point for the assessment throughout. We have reviewed a great amount of technical data and safety analyses and monitored Posiva’s operations in many ways," says Antti Tynkkynen , Project Manager for the Posiva regulatory control project. Since 2000, STUK and its external experts have contributed a total of more than 250 man-years to project supervision and safety licence assessment.<br>Safety assessment and development continues<br>STUK proposes conditions for the operating licence to ensure the continuation of safety assessment and development also during the facility's operation.<br>STUK proposes that Posiva must carry out the first periodic safety assessment within ten years of granting the operating licence. At the same time, Posiva must update the long-term safety justification to correspond to the final disposal system to be deployed. In addition, Posiva must provide STUK with detailed plans for the final disposal facility for low- and intermediate-level waste and a safety justification for long-term safety based on them before the construction of the...