More than a decade later than planned, the third nuclear reactor in the Finnish nuclear power plant Olkiluoto was put into operation.
The operating company Teollisuuden Voima Oyj announced that the Olkiluoto 3 reactor (OL3 for short) was started up on Tuesday at 3.22 a.m.
The power level is now to be gradually increased before OL3 is connected to the national power grid as planned at the end of January.
The reactor is expected to reach full capacity in June, when it is estimated to cover 14 percent of Finland's total electricity demand.
The radio station Yle spoke of a "historic day for Finnish nuclear power".
Finland gets almost a third of its electricity from nuclear energy.
Therefore, not far from the power plant on the island of Olkiluoto, a repository for nuclear waste is to be built.
The first used fuel rods should be put into storage in just a few years.
The operating company expects to have the world's first functional repository for highly radioactive waste in the mid-twenties.
The waste is said to be enclosed in copper capsules and stored 450 meters below the surface in granite rocks that are almost two billion years old.
The Finnish population is more open to nuclear power than the German, said Janne Mokka, the head of the operator, told the FAZ last year Nuclear power plants used up, also had to take care of the waste and build a repository. "
Olkiluoto is one of the two nuclear power plants in Finland.
The plant is located around 250 kilometers northwest of Helsinki.
The OL3 reactor should actually have gone into operation in 2009, but there were repeated delays and increased construction costs.