Finnish utility Teollisuuden Voima Oyj (TVO) has handed over an acknowledgment of receipt to the Areva-Siemens consortium for the EPR at unit 3 of the Olkiluoto NPP (OL3). The trial operation of OL3 ended on 16 April 16, when the regular electricity production of the plant unit began. TVO said the final steps of the trial operation have been analysed and the project has been completed. The final receipt of the plant unit takes place after the end of the two-year warranty period. However, plant supplier warranty liabilities will continue in certain respects for a maximum of eight years.

TVO confirmed that commercial operation of the plant unit would start on 1 May, which means, among other things, that the activation of project costs would be stopped and depreciation would begin. The shareholders' right to the electricity generated by OL3 and the obligation to bear the annual costs of electricity generation are determined in accordance with TVO's articles of association. OL3 will produce about 15% of Finland's total electricity consumption, while the Olkiluoto plant overall (units1-3) will generate about 30%.

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 began in 2005, with completion of the reactor originally scheduled for 2009, but the project has had various delays and setbacks.

Construction of OL3 began in 2005 and various setbacks and delays mean the plant is some 14 years behind the original schedule and significantly over budget. OL3’s final price tag is put at some $11bn ($12bn), some three times what was initially estimated. OL3 attained first criticality in December 2021 and was connected to the grid on in March 2022. The 1600 MWe EPR was operated at full capacity for the first time in late September 2022. However, cracks were identified in the impellers of the feedwater pumps located in the turbine island.

Tests at full power were continued after extensive investigations with two cracked impellers and two spare impellers. To avoid the recurrence of similar damage, impellers with more robust measurements were designed for OL3. New impellers were installed in all four of OL3’s feedwater pumps during a recent scheduled outage and the plant supplier carried out inspections in preparation for resumed trial operation. The reactor was briefly back in test mode in late December and early January before being closed again for maintenance.

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). The private owners are mostly heavy industry with a high demand for base-load power, which makes low costs essential. The owners take their shares of electricity at cost and sell any unused electricity into the Nordic market. Output is therefore effectively contracted to each owner over the life of the plant.

Image: Olkiluoto 3 (courtesy of TVO)

Date: Wednesday, 26 April 2023
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