Finland's Olkiluoto 3 nuclear reactor reduces output by 450 MW due to fault

Finland's largest nuclear reactor, Olkiluoto 3 (OL3), is currently operating at a reduced power level of approximately 300 MW. The unit's normal net power output is around 1,600 MW, and its generation accounts for about 14% of Finland's total electricity demand. According to Teollisuuden Voima (TVO), as reported by Tekniikka & Talous, the power reduction is due to a fault in one of the reactor-side circulation pumps. The damaged circulation pump has been repaired and is under monitoring, and the power level of Unit 3 is expected to return to normal on August 18. The circulation pump's function is to circulate cooling water through the reactor core.

Meanwhile, Olkiluoto 2 has also been operating at a reduced power level of approximately 155 MW since mid-July to mitigate the risk of faults. The unit's low-power generation state will continue until the end of 2027. Currently, the combined output of the two Olkiluoto nuclear reactors is approximately 455 MW below normal levels.

Olkiluoto 3 is Finland's largest nuclear reactor, with a normal net power output of approximately 1,600 MW, meeting about 14% of Finland's electricity demand. The three units at the entire Olkiluoto nuclear power plant together supply approximately 30% of Finland's electricity generation.