OKG AB is a Swedish corporation that owns and operates the Oskarshamn Nuclear Power Plant. Founded in 1965, OKG is located on the Simpevarp peninsula, approximately thirty kilometers north of Oskarshamn. The plant's 3 three boiling water reactors (BWR), O1, O2, and O3, have a combined installed gross power output of 2,603 MW and at maximum power, the reactors accounted for 10% of the electricity generation in Sweden.
A decision to shut down units O1 and O2 was made in 2015. The decision entails that there will be no future investments at unit O2 and the reactor will not be restarted. On 17 June 2017, unit O1 delivered its final kilowatt-hours of electricity. OKG is still one of the major suppliers of baseload to the Nordic power supply system. Unit O3 is with the installed capacity of 1,450 MW one of the largest boiling water reactors in the world
OKG is part of the international energy group Uniper's Swedish operations. The Uniper Group owns 54.5% and the Fortum Group owns the other 45.5%.
Unit O1 was Sweden's first commercial nuclear power unit commissioned in 1972. O2 and O3 have been in operation since 1974 and 1985 respectively. Unit O3 is one of the largest boiling water reactors in the world with a gross capacity of 1,450 megawatts.
The total plant investment at Oskarshamn is approximately SEK 20 billion.