Last week, TVO submitted an application to Stuk asking for green light to proceed towards first criticality at the 1,600-MW Generation III pressurised water reactor unit. First criticality at a nuclear plant means achieving a controlled, self-sustaining nuclear fission chain reaction in the reactor core for the first time
Stuk said Olkiluoto-3 has met the preconditions for criticality and low power tests, but before the reactor is made critical the regulator will still verify the startup preparedness of the plant.
The regulator also said that it will monitor power ascension testing onsite while TVO will still need a permission to increase output levels by more than 5%, followed by 30% and 60%.
TVO said Olkiluoto-3 is still scheduled to become critical in December, while electricity production, and hence grid connection, is expected at the end of January 2022. Commercial operation remains on schedule for June 2022.
First fuel loading at Olkiluoto-3 was completed in March. First criticality was scheduled for January 2022, according to the latest timeframe from this summer.
Construction of the plant, supplied by an Areva-Siemens consortium, began in August 2005, but was later delayed several times by the supplier and suffered consequent cost overruns.
