Europe's largest nuclear reactor, Olkiluoto 3 (OL3) began generating electricity again early Thursday after scheduled annual maintenance dragged on more than a month longer than expected, pushing electricity prices up in Finland.
The unit was plugged back into the main grid at 1.15am Thursday after 74 days of maintenance.
OL3 began full commercial production just over a year ago, some 14 years behind schedule. The project was first launched in 2005.
The schedule for its first annual maintenance was changed several times and eventually extended by more than a month. The maintenance, which started at the beginning of March, was originally supposed to be completed on 8 April.
In a press release on Thursday, plant owner Teollisuuden Voima (TVO) blamed the delays on issues such as a longer-than-expected time required to shut down the unit and the technical problems detected during the maintenance.
According to TVO, valuable lessons were learned regarding the planning and implementation of future maintenance.
Despite the delays, electricity production director Marjo Mustonen expressed satisfaction with the end result.
"The planned work was carried out safely. The main goal of annual maintenance is always safe implementation. The pressure was intense, but our organisation was able to react well to unexpected situations," she said in a press release on Thursday.
Olkiluoto 3 accounts for about 14 percent of Finland’s electricity production.
The 45-year-old Olkiluoto 1 reactor nuclear power plant is still undergoing annual maintenance, which should be completed in two weeks.
Users with an Yle ID can leave comments on our news stories. You can create your Yle ID via this link. Our guidelines on commenting and moderation are explained here.