Electricity production at the Olkiluoto nuclear power plant's third unit was at a standstill on Monday as repairs continued.
Power plant owner TVO said on Monday that the unit would be back on line later in the day, but later backpedalled, saying that fixing it would take longer than expected.
"Repairing the fault will take more time, so according to current information, the plant will return to electricity production in approximately two days," the company said in a social media post on Monday afternoon.
The Olkiluoto 3 (OL3) reactor's electricity production was interrupted on Sunday evening due to a turbine malfunction. TVO blames a malfunction of the generator seal oil system.
According to the company, the incident has no impact on nuclear safety.
"This is the kind of fault that, of course, requires a few hours of repair time, but then we can get back to continuing production. It's not a serious fault," communications manager Johanna Aho said on Monday.
Olkiluoto's smaller 1 and 2 reactors are producing electricity normally.
Smooth autumn until now
According to Aho, OL3's operations have been steady in recent months.
"After the spring annual maintenance, there have been almost no malfunctions, with the exception of one, and this is expected to be only a short malfunction," she said.
Olkiluoto 3's first annual maintenance was completed in May, taking five weeks longer than expected.
The additional weeks were caused by issues such as a longer-than-expected time required to shut down the plant unit and technical problems discovered during maintenance.
Olkiluoto 3 accounts for about 14 percent of Finland’s electricity production.
Construction of the plant in Eurajoki on Finland's west coast began 50 years ago.
1.20pm: Updated with delay.
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