Finland's Olkiluoto 3 unit reduces power output due to main coolant pump fault

Finnish utility Teollisuuden Voima (TVO) said on August 17 that Unit 3 of the Olkiluoto nuclear power plant (OL3) will continue to operate at a stable power output of approximately 1,300 MW, about 84% of full capacity, for the coming weeks due to technical faults in two main coolant pumps in the nuclear island. The unit's rated generating capacity is approximately 1,600 MW.

TVO stated that the faults were discovered during this summer. Since then, the unit has reduced its output power and investigations have been conducted into the causes of the faults and corrective measures. Under the latest arrangement, OL3 will continue operating at a reduced power level to monitor the effectiveness of corrective actions until the unit begins its scheduled annual outage on September 10, 2026.

TVO stated that the technical issue will not affect nuclear safety.

Unit 1 of the Olkiluoto nuclear power plant (OL1) is currently operating normally. Regarding Unit 2 (OL2), TVO previously disclosed that the unit is operating at reduced power due to rotor-related arrangements, with a new improved rotor expected to arrive at Olkiluoto by the end of 2027.