Olkiluoto 3’s electricity production continues in February at mainly full power


The impellers of Olkiluoto 3’s (OL3) feedwater pumps will be replaced with impellers with more robust measurements during the ongoing production break. After this, electricity production will continue at mainly full power.

New impellers will be installed in all four of OL3’s feedwater pumps already during the ongoing production break. Electricity production continues immediately after the installations in the beginning of February.

Almost all significant tests of the test production phase were completed at the end of December and in January, prior to starting the production break. The plant unit worked well and according to plan in the tests. The latest of the significant tests, the so-called Fault Ride Through (FRT), was interrupted by transmission system operator Fingrid. After the installation of the new impellers, electricity production is continued with a demo phase, during which the plant unit produces electricity to the grid at mainly full power. Regular electricity production starts in March 2023.

Information on electricity production during the test production phase is published on TVO’s website at www.tvo.fi/ol3forecast. A market message is published in NordPool regarding any significant changes.

*In autumn 2022, cracks were identified in the impellers of the feedwater pumps located in OL3’s turbine island. Tests at full power were continued after extensive investigations with two cracked impellers and two spare impellers. The observations made during the feedwater pumps’ inspections were in accordance with the calculations and analyses performed earlier. To avoid the recurrence of similar damage, impellers with more robust measurements were designed for OL3. The plant unit’s electricity production will be continued after the installation of the new impellers.

For further information, please contact:
Johanna Aho, Head of Communications, tel. +358 40 729 0822