Finnish utility Teollisuuden Voima Oyj (TVO) has issued an acceptance certificate to the Areva-Siemens consortium for the Olkiluoto 3 (OL3) EPR, which began regular electricity production on 16 April. It said the 1600 MWe reactor is scheduled to enter commercial operation on 1 May.

Olkiluoto 3 (Image: TVO)

The Areva-Siemens consortium constructed the OL3 plant under a fixed-price turnkey contract. They have joint liability for the contractual obligations until the end of the guarantee period of the unit. Construction of Olkiluoto 3 began in 2005, with completion of the reactor originally scheduled for 2009, but the project has had various delays and setbacks.

OL3 attained first criticality on 21 December 2021 and was connected to the grid on 12 March 2022. The EPR, a 1600 MWe pressurised water reactor, then entered a phase of test production during which some 3300 tests were conducted and more than 9000 test reports collated.

"The last phases of trial operation have been analysed and the project has been completed," TVO declared.

"The plant unit ordered with a turnkey contract has been accepted as received today," TVO said. "The final acceptance of the plant unit takes place after the end of the two-year warranty period. Even after that, the plant supplier's warranty responsibilities continue in certain parts for a maximum of eight years."

TVO said OL3 will enter commercial operation on 1 May, "which means, among other things, that the capitalisation of project costs will be stopped and the recording of depreciation will begin".

"The shareholders' right to electricity produced by OL3 and the obligation to bear the annual costs arising from electricity production are determined in accordance with TVO's articles of association," the company noted.

TVO is 27% owned by Fortum and 57% owned by Pohjolan Voima Oy (the major shareholders of which are pulp and paper manufacturers UPM Oyj and Stora Enso Oyj). Owners take their shares of electricity at cost, any unwanted portion being sold by them into the Nordic market. This means that output is effectively contracted to each owner over the life of the plant. The private owners are mostly heavy industry with a high demand for base-load power, and hence low costs are critical for them.

OL3 will produce about 15% of Finland's total electricity consumption, while the Olkiluoto plant as a whole will generate about 30% of the country's electricity.