The Olkiluoto 3 EPR plant unit started up

OL3’s reactor started up today on Tuesday, December 21 at 3.22 a.m. The moment of the startup* was historical. A new nuclear power plant unit was last commissioned in Finland over 40 years ago, and even in Europe this event last occurred about 15 years ago. OL3 will produce approximately 14 percent of Finland’s electricity once regular electricity production has started.

- This moment will forever be remembered as a demonstration of persistent work for the commissioning of our new plant unit. It reflects strong nuclear professionalism and a will to make Finland’s greatest act for the climate a reality, says Senior Vice President for Electricity Production, Marjo Mustonen.

- A wonderful highlight of the project was completed together with the plant supplier. Something even better is in store in January, when OL3 will be connected to the national grid, i.e., electricity production starts, says OL3 Project Director, Jouni Silvennoinen.

After the startup, the power level will be increased gradually, and commissioning tests will be implemented at every power level. Electricity production starts at a 25 percent power level, which is approximately 300-400 MW**, at the end of January 2022. OL3’s regular electricity production starts in June 2022. Output during the test production phase is communicated on TVO’s website at www.tvo.fi/ol3forecast.

*In order to launch the reactor, so-called primary neutron sources are needed, which have been placed into three fuel assemblies in the reactor. These sources release neutrons, which start the splitting of atomic nuclei. This chain reaction keeps the nuclear reactor running.

** Updated 21.12.2021 at 19.40

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