The Olkiluoto 3 EPR has started electricity production (Photo: TVO)The EPR reactor at unit 3 of Finland’s Olkiluoto nuclear power plant, which was commissioned in December 2021, was finally connected to the national grid with a capacity of 103MWe on 12 March following a series of delays.

Plant operator/owner Teollisuuden Voima Oyj (TVO) said that, during a trial period of approximately four months, the capacity of OL3 will be gradually increased to 1600MWe.

“This is a large production volume, about 3-4TWh during the trial period, which corresponds to about 10% of Finland's electricity needs, TVO noted, adding that power levels vary significantly during test operation.

“The start of electricity production has been carefully prepared and this is a great demonstration of our expertise. OL3 is a significant addition to domestic clean electricity production, which accounts for more than 90%. At the same time, the need for electricity imports will be reduced by less than half,” said production director Marjo Mustonen.

OL3 project manager Jouni Silvennoinen noted: “The start of electricity generation is a key milestone in our joint project with plant supplier Areva-Siemens. I would like to thank all the nuclear professionals who have worked on the project over the years. Now we are continuing the trial operation by gradually increasing the plant's capacity and preparing for the start of regular electricity production.”

OL3's regular electricity production will begin in July 2022 after which it will account for about 14% of Finland's total electricity consumption. The reactor was initially expected to start electricity generation by the end of January but this was then delayed until the first half of February and then to the end of February. The main reason for the delay was an unplanned reactor shutdown that occurred on 14 January.  

The OL3 EPR plant supplier consortium constructed the plant under a fixed-price turnkey contract. The consortium of plant suppliers includes AREVA GmbH, AREVA NP SAS and Siemens AG, which are jointly and severally liable for the obligations under the plant supply contract until the end of the plant unit's warranty period.

Construction of OL3 began in 2005. Completion of the reactor was originally scheduled for 2009.

The Olkiluoto 3 EPR has started electricity production (Photo credit: TVO)