The Olkiluoto 3 EPR plant unit’s electricity production has started


The electricity production of Olkiluoto’s third nuclear power plant unit started today on Saturday, 12 March 2022, at 12.01 p.m. Olkiluoto 3 EPR (OL3) significantly increases domestic electricity production.

The startup of OL3’s reactor took place on 21 December 2021, after which the power output has been gradually increased to approximately 27 percent. Today on Saturday, 12 March 2022, at 12.01 p.m., the plant unit has been connected to the national grid at a power output of 103 MW. The moment was long-awaited; OL3 significantly improves Finland’s electricity self-sufficiency and helps in achieving carbon neutrality goals. A new nuclear power plant was previously commissioned in Finland over four decades ago.

During the approximately four-month test production phase, the OL3 plant unit’s power output will be gradually increased to 1,600 MW. This output is considerable; approximately 3-4 terawatt hours during the test production phase, which corresponds with approximately 10 percent of Finland’s electricity demand. The power output varies considerably during test production.

– The start of electricity production has been carefully prepared for, and this is a great demonstration of our expertise. OL3 is a significant addition to clean electricity production in Finland, the share of which will rise to over 90 percent. At the same time, the need for the import of electricity will decrease to below half, says Senior Vice President of Electricity Production, Marjo Mustonen.

– The start of electricity production is a central milestone in our joint project with the plant supplier Areva-Siemens. I want to thank all the nuclear professionals who have worked in this project during the years. Now, we will continue the test production by gradually increasing the plant unit’s power output and prepare for the start of regular electricity production, says OL3 Project Director, Jouni Silvennoinen.

OL3’s regular electricity production starts in July 2022. Output during the test production phase is communicated on TVO’s website at Once regular electricity production has started, OL3 will produce about 14 percent of Finland’s total electricity consumption.

For further information and interview requests, please contact:
Johanna Aho, Head of Communications, Tel. +358 (0)40 729 0822