As of 2023, Finland has five operating nuclear reactors in two power plants, all located on the shores of the Baltic Sea. Nuclear power provided about 34% of the country's electricity generation in 2020. The first research nuclear reactor in Finland was commissioned in 1962 and the first commercial reactor started operation in 1977. The fifth reactor started operation in April 2023. Finland's nuclear reactors are among the world's most productive, with an average capacity factor of 95% in the 2010s. List of commercial nuclear reactors#Finland Loviisa Nuclear Power Plant Located in Loviisa, on the south coast (Gulf of Finland), the plant comprises two VVER-440 pressurized water reactors built by Soviet Atomenergoexport, but fitted with Western instrumentation, containment structures and control systems. The plant is owned and operated by Fortum. Electrical production started in 1977 and 1980, with the reactors now producing 507 MWe each. On 26 July 2007 new licenses were granted to Fortum to operate the units until 2027 and 2030, conditional on safety reviews before 2015 and 2023. Olkiluoto Nuclear Power Plant The Olkiluoto plant is owned by Teollisuuden Voima (TVO), and is located in Eurajoki, on the west coast, near Rauma. It has two boiling water reactors currently producing 890 MWe each. They were built by the Swedish company Asea-Atom (nowadays ABB), and went online in 1978 and 1980. Areva has built a third reactor at the Olkiluoto site for a total cost of price of over €8.5 billion. It is a European Pressurized Reactor (EPR), and has a power output of 1,600 MWe. The reactor was originally scheduled to start production in 2009, but was delayed by 14 years. Regular electricity production started in April 2023. FiR 1 was a small research reactor located in Otaniemi, Espoo; a TRIGA Mark II, built for the Helsinki University of Technology in 1962. Owned by the VTT Technical Research Centre of Finland since 1971, it had a power output of 250 kW. It was mainly used in boron neutron capture therapy and research.