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The greatest single climate act in Finland, the Olkiluoto 3 (OL3) plant unit, has been taken into use in Olkiluoto. With the commissioning of the third most powerful nuclear power unit in the world, approximately 30% of Finland’s electricity come from one island, where the entire lifecycle of nuclear power is managed.

OL3’s fuel loading into the reactor was completed in April 2021, and the nuclear reaction was initiated for the first time in December of the same year. The plant unit was connected to the national grid in March 2022. The test production program was completed in April 2023. The plant unit's regular electricity production has started.

With the regular electricity production of OL3, 30% of Finland's electricity will soon come from one island.

OL3 is an EPR (European Pressurized Water Reactor) plant unit with a net electrical output of approximately 1,600 MW. OL3 includes modern proven technology and advanced new safety features. Particular attention has been paid to factors that further increase the safety of the plant, such as the prevention and management of severe accidents, as well as to the efficiency, including cost-efficiency, of production.

OL3 was ordered as a turnkey delivery from a consortium (plant supplier) formed by AREVA GmbH, AREVA NP SAS, and Siemens AG. OL3 has been a major international project. At its busiest, the project employed around 4,500 people.

Finland's greatest climate act

With the regular electricity production of OL3, Finland’s self-sufficiency in clean electricity grows – the share of carbon-free electricity production will rise from 89% to about 93%. The electricity production OL3 also reduces Finland's import of electricity by about 60%.

‍OL3's electricity production covers approximately 14% of Finland's electricity demand. The electricity produced by the plant unit during one year, 12 TWh, is enough to heat 5,2 million apartments or charge 3,6 million electric cars, for example.