× This site uses cookies. By continuing to browse the site, you are agreeing to our use of cookies. Read more from here
Home  /  PRODUCTION  /  Plant units  /  OL3


Olkiluoto 3 (OL3) is an EPR (European Pressurized Water Reactor) plant unit that 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.

The development is based on plants commissioned in France (N4) and Germany (Konvoi). Once complete, the unit will be one of the best in the world in terms of operation, safety, and reliability.

The new plant unit is located at the western end of the Olkiluoto island, next to the OL1 and OL2 units. The net electrical output of the unit will be approximately 1,600 MW.

Olkiluoto 3 EPR was ordered as a turnkey delivery from a consortium (plant supplier) formed by AREVA GmbH, AREVA NP SAS, and Siemens AG.

The commercial electricity production of the plant unit was originally supposed to commence at the end of April 2009. According to the latest schedule update by the plant supplier, regular production at the plant unit will begin in January 2020.

OL3 EPR is a major international project, and approximately 1,500 people worked at the Olkiluoto construction site at the end of 2018. An uncompromising safety culture is a basic requirement at the site, and occupational safety indicators remained at a good level.

Construction engineering work mostly completed

Construction work have in most parts been completed at the plant units, and installation works are being finalised. The operating personnel were granted operator licences by Radiation and Nuclear Safety Authority (STUK) in December 2018. The hot functional testing (HFT) was completed in May 2018. In HFT, the nuclear and turbine island operated for the first time together as an entity without nuclear fuel. The Finnish government granted an operating licence for OL3 EPR on 7 March 2019.

First commissioning stage of the turbine island was completed. Some of the systems and components will remain in operation, while others have been stored in accordance with a separate plan.

TVO allows no exceptions from legal obligations in its own operations, and requires the same from all companies with operations at Olkiluoto. TVO requires the plant supplier and subcontractors to observe, among other things, the laws and regulations governing taxation and working hours, as well as union contracts. TVO has worked systematically to eradicate the gray economy and to promote related legislation.

Compliance is continuously monitored. There are several alternative channels available onsite for reporting any deficiencies or for expressing concerns to TVO. TVO reports any compliance non-conformance to the plant supplier and requires the plant supplier to investigate the situation and take the necessary corrective action.  TVO also reports any suspected non-conformance to public authorities, when necessary. Authorities can be granted permanent access permits to the OL3 site to facilitate and streamline unannounced inspections.

TVO is involved in a cooperation team established at the initiative of the Employment and Economic Development Office of Rauma, processing current issues related to the OL3 project and discussing possible methods of advancing official procedures. The team includes representatives from the Ministry of Economic Affairs and Employment, the Regional State Administrative Agency, the Finnish Centre for Pensions, the tax administration, the police, the local parish, STUK, TVO, the plant supplier consortium, AREVA-Siemens, and the key trade unions.