The Finnish Government has granted environmental technology and waste management company Posiva Oy the operating licence for the encapsulation and final disposal facility for used nuclear fuel located in Olkiluoto, Eurajoki. This is the first time a deep geological repository for permanent nuclear waste storage has reached this level of regulatory clearance. The decision comes 22 years after construction began on the repository, ending over 40 years of systematic research and development.
The licence is valid until the end of 2070. The facility will process waste generated by Finland’s existing NPPs in Olkiluoto and Loviisa.
According to the licence, Posiva may also possess, produce, process, store and dispose of low-level and intermediate-level radioactive waste generated by the encapsulation plant and final disposal facility and by the operation and decommissioning of nuclear facilities owned by its shareholders provided that the total volume of the waste does not exceed 3,000 cubic metres, of which no more than 1,500 cubic metres may be designated for final disposal.
Posiva operates as a private joint venture owned entirely by Finland’s two commercial nuclear power producers. Teollisuuden Voima Oyj (TVO) owns a 60% share and Fortum Power and Heat Oy owns a 40% share. Legally, these two utilities are entirely responsible for the final disposal of the waste their reactors produce; they fund Posiva’s operations through advance contributions compiled into the Finnish State Nuclear Waste Management Fund.
The licence also permits the final disposal of certain other radioactive waste and nuclear materials generated in Finland to a limited extent. This includes certain radioactive waste generated in healthcare and research institutions.
Posiva is authorised to handle and permanently store a maximum of 6,500 tonnes of uranium. The amount of used nuclear fuel to be disposed of corresponds to approximately 3,300 disposal canisters. The plan is to dispose of a maximum of 60 canisters a year. The final disposal operations are estimated to continue until the 2120s, after which the repository will be backfilled and closed and responsibility for the used nuclear fuel will then be transferred to the State in accordance with the Nuclear Energy Act.
Posiva is required to submit a periodic safety assessment and an updated long-term safety justification to STUK within ten years of the granting of the licence. Periodic safety assessments will also be carried out during the operation.
STUK will conduct a final inspection to ensure that all conditions for safe operation have been met before the facility is commissioned after which Posiva may will start operating the facility.
The underground repository, known as Onkalo (meaning “cave” in Finnish), relies on a multi-barrier safety system. Used nuclear fuel is packed into corrosion-resistant copper canisters. These are lowered into disposal tunnels blasted more than 400 metres deep into 1.9bn-year-old stable bedrock. The holes are packed with bentonite clay and plugged with steel-reinforced concrete.
The repository is designed to safely isolate the toxic radioactive waste for at least 100,000 years, when radiation levels will finally return to that of natural uranium ore. Final disposal will not begin immediately. Posiva must first complete final operational commissioning tests and inspections. These remaining trials must be verified and approved by Finland’s Radiation and Nuclear Safety Authority (STUK – Säteilyturvakesku) before radioactive waste can be lowered underground.
Posiva will now transition towards production operation which will go on for over a hundred years. The safety assessment issued by STUK in August constituted the central rationale for the Government’s decision.
“This is a great and historic day for both Posiva and Finland,” said Posiva’s President & CEO Ilkka Poikolainen. “In addition to comprehensive expertise, the stability of the society and the predictability of the operational environment were prerequisites for the operating licence…. This solution has not been built because it was easy. It was built despite not being easy. Because it is the responsible thing to do. And because it is the right thing. Like we have said from the very start: only safe final disposal is possible. That is why we will take the time to complete also the final stages with care.”
Posiva has already attracted significant international attention, and the pioneering work of the company sets an example to countries developing their own final disposal solution. The unique expertise is already exported to 19 different countries by Posiva Solutions Oy.
“A total solution like this is not built by just one organisation, and not in just a few years,” said Poikolainen. “It has its background in the forward-looking decisions of the society, independent regulatory oversight, strong commitment from our owners, and the efforts of a wide-reaching group of experts. The thanks must go to everybody involved in this work.”
