Finland's Largest Nuclear Plant Undergoes Extended Repairs
Olkiluoto 3 is Finland’s most powerful individual electricity generator and the largest nuclear power plant unit in Europe.
Annual maintenance on Olkiluoto 3 will last more than two months because of pipe stress discovered during testing.
Olkiluoto 3, Finland’s largest nuclear power plant unit, will not resume electricity production on Saturday, November 7, as previously stated by Teollisuuden Voima (TVO). The company now estimates that maintenance work will not be completed until November 18.
In September, TVO announced that maintenance on the nuclear power plant would last approximately 50 days, until late October. The outage has now been extended to more than two months.
Marko Kesti, director of maintenance at TVO, explains that the maintenance period was extended because of issues discovered during the power plant’s testing phase. “During these tests, the piping in the condenser system was subjected to greater-than-normal stress. Due to this exceptional strain, the piping cannot be put into service immediately; it requires further repairs and inspections before electricity production can safely resume,” Kesti explains.
Kesti notes that Olkiluoto 3 is expected to be connected to the electricity grid on Wednesday, November 18, before beginning a controlled ramp-up to full power.
“The plan is to generate electricity without interruption for another 18 months, lasting until the spring of 2028,” says Kesti.
Olkiluoto 3 has an electrical output of 1,600 megawatts, accounting for approximately 10–15 percent of Finland’s total electricity production.
Olkiluoto 2 is also currently operating at a lower-than-normal power level. Consequently, 1,755 megawatts of nuclear generating capacity are currently unavailable.
Situation Concerns Electricity Users
Pasi Kuokkanen, managing director of Elfi (Finnish Electricity Users)—an organization representing major electricity consumers—describes the delays as highly unfortunate. “From the perspective of an electricity consumer, we are extremely concerned about this situation. We hope that the matter is resolved as soon as possible and that Olkiluoto 3 returns to long-term, reliable operation,” Kuokkanen says.
In recent days, spot-market electricity prices have reached as high as 50 cents per kilowatt-hour. According to Kuokkanen, the absence of Olkiluoto 3 has contributed significantly to the price spikes seen at this time of year.
Maarit Uusitalo, head of market solutions at the transmission system operator Fingrid, told Kauppalehti in October that a lack of production capacity typically drives up electricity prices by reducing supply.
She explained that while wind power can, at best, compensate for the shortfall in stable generation, its inherent variability—combined with the outage at Olkiluoto 3—makes the electricity market more sensitive to wind conditions.
“This can manifest as more pronounced price volatility,” Uusitalo said.
On Thursday, spot-market electricity was very inexpensive thanks to a high volume of wind power. At around 2:00 PM, electricity cost just 0.6 cents per kilowatt-hour. On Friday, however, the price is set to rise, reaching 22.7 cents per kilowatt-hour by 9:00 AM. Weather forecasts predict windy conditions for the weekend. However, the wind is expected to die down early next week, and temperatures are set to drop across the country.
Source: Kauppalehti (in Finnish)