Friday, 23 May 2025
Radioactive waste management company Posiva submitted its application, together with related information, to the Ministry of Economic Affairs and Employment on 30 December 2021 for an operating licence for the used fuel encapsulation plant and final disposal facility currently under construction at Olkiluoto. The repository is expected to begin operations in the mid-2020s. Posiva is applying for an operating licence for a period from March 2024 to the end of 2070.
The government will make the final decision on Posiva’s application, but a positive opinion by the Radiation and Nuclear Safety Authority (STUK) is required beforehand. The regulator began its review in May 2022 after concluding Posiva had provided sufficient material. The ministry had requested STUK’s opinion on the application by the end of 2023. However, in January last year, STUK requested the deadline for its opinion be extended until the end of 2024. In December, the ministry extended the deadline for the regulator’s opinion to 31 December 2025.
STUK has now said that there are still deficiencies in the materials submitted for review by Posiva, “which the company must correct”. The regulator also noted that Posiva has made changes to its original plans, which has required updating the materials. “The updates have delayed STUK’s work more than expected in the early part of the year,” it said.
Although STUK’s assessment of the application is in the final stages, the statement and safety assessment cannot be completed until it has assessed and approved all of Posiva’s operating licence application materials.
“As soon as we receive the remaining materials we need and the supplements we requested, the assessment can be made and the statement can be completed,” said STUK Project Manager Antti Tynkkynen.
“If future Posiva data updates do not cause further clarification, it is possible that the review of the licence application data will be completed well before the end of this year,” STUK said.
At the repository, used fuel will be placed in the bedrock, at a depth of about 430 metres. The disposal system consists of a tightly sealed iron-copper canister, a bentonite buffer enclosing the canister, a tunnel backfilling material made of swellable clay, the seal structures of the tunnels and premises, and the enclosing rock.
Posiva announced in late August the start of a trial run – expected to take several months – of the operation of the final disposal facility, albeit still without the used fuel.
“One of the time-consuming issues has been the supervision of the test runs of the disposal facility,” STUK said. “During the first quarter of 2025, STUK required Posiva to investigate the status of the systems used in the encapsulation and disposal facility and the test runs for the entire facility. STUK has not yet received most of the test run reports for the safety-classified systems and has not been able to assess the test runs as a whole.”
STUK is also assessing the readiness of Posiva’s organisation to start operating the final disposal facility. In the autumn of 2024, STUK began enhanced supervision of Posiva’s organisation. In parallel, STUK introduced incident investigation methods at the beginning of the year in order to deepen its understanding regarding the observations it has made concerning Posiva’s organisation as well as the factors underlying them. At the same time, STUK is looking for ways to plan, target and develop its own supervision.
“I find it positive that, in addition to our own estimates, the authority is taking steps to independently ensure that our operations meet all the set safety requirements,” said Ilkka Poikolainen, President and CEO for Posiva.
The government granted Posiva a construction licence for the project in November 2015 and construction work on the repository started in December 2016. Once it receives the operating licence, Posiva can start the final disposal of the used fuel generated from the operation of TVO’s Olkiluoto and Fortum’s Loviisa nuclear power plants. The operation will last for about 100 years before the repository is closed.
Article researched and written by WNN’s
