Finland has moved a step closer to becoming the first country to begin the permanent geological nuclear fuel disposal after the country’s radiation safety regulator concluded that Posiva Oy’s final disposal facility meets the required safety standards.
The Radiation and Nuclear Safety Authority (STUK) has issued a favourable statement to Finland’s Ministry of Economic Affairs and Employment, confirming that Posiva’s encapsulation and final nuclear fuel disposal facility at Olkiluoto, Eurajoki, complies with the country’s nuclear safety legislation.
The decision removes the principal regulatory barrier to granting an operating licence. If approved by the Finnish Government, the project would mark a global first, as no other geological repository for spent nuclear fuel has yet reached the operating licence stage.
However, STUK stressed that nuclear waste disposal cannot begin immediately, with a separate regulatory approval still required before operations can commence.
Petteri Tiippana, STUK’s Director General, highlighted the magnitude of the facility: “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.”
Regulator confirms safety requirements have been met
STUK’s assessment found that the facility satisfies the safety requirements set out under Finland’s Nuclear Energy Act and associated regulations. The regulator concluded there are no radiation or nuclear safety obstacles preventing the Government from issuing an operating licence.
The Ministry of Economic Affairs and Employment will now prepare the case for the Finnish Government, which will make the final licensing decision. A positive opinion from STUK is a mandatory prerequisite for that process.
Even if the operating licence is granted, Posiva must still demonstrate that every safety requirement for the start of operations has been fulfilled. STUK will make that determination through a separate approval process before any spent nuclear fuel is placed underground.
How Finland’s nuclear fuel disposal system works
Posiva’s disposal concept is designed to isolate high-level radioactive waste deep underground for extremely long timescales.
Spent nuclear fuel will first be sealed inside robust disposal canisters at an above-ground encapsulation plant. The canisters will then be transported to a repository excavated approximately 400 to 450 metres below ground in stable bedrock.
The safety strategy relies on multiple engineered and natural barriers working together. The fuel is protected by iron and copper canisters, which are surrounded by bentonite clay before being emplaced within the surrounding rock formation.
Together, these barriers are intended to prevent or significantly delay the movement of radioactive materials into the environment.
Long-term safety remains central to oversight
A key part of STUK’s review focused on the repository’s long-term performance, examining how the disposal system and surrounding geology are expected to evolve over thousands of years.
The regulator evaluated how effectively the engineered barriers and bedrock would continue to contain radioactive substances and limit any potential releases into the environment. Alongside the technical assessment, STUK also reviewed Posiva’s organisational readiness to begin operating the facility.
The regulator concluded that additional oversight will be required throughout the repository’s operational lifetime and has proposed several licence conditions to ensure safety assessments continue as the project progresses.
Ongoing monitoring planned throughout operation
Posiva has applied for an operating licence that would remain valid until the end of 2070.
During that period, STUK will continue supervising the facility under the nation’s Nuclear Energy Act and has recommended that Posiva complete its first periodic safety review within 10 years of receiving an operating licence.
The company will also be required to update its long-term safety case to reflect the final disposal system as it is ultimately deployed.
In addition, before constructing a separate repository for low- and intermediate-level radioactive waste, Posiva must submit detailed design plans and a long-term safety justification for regulatory approval.
If the Finnish Government grants the operating licence and subsequent operational approvals are secured, Finland will become the first nation to transition geological nuclear fuel disposal from decades of planning and construction into licensed operation, setting a significant precedent for radioactive waste management programmes worldwide.
