OKG was founded in 1965 and today owns and operates three nuclear reactor units – Oskarshamn 1, 2 and 3 – which together account for ten per cent of the total electricity generation in Sweden. OKG presently has approximately 850 employees and an annual turnover of around SEK 3 billion. The plant is located on the Swedish east coast, 30 kms north of Oskarshamn. Oskarshamn 1, also Sweden's first commercial nuclear power unit, was commissioned in 1972. Oskarshamn 2 has been in operation since 1974 and Oskarshamn 3 was put into commercial operation in 1985. Each reactor is shut down every year for three to six weeks for maintenance, safety system control and replacement of 20 per cent of the fuel elements. These planned outages normally occur between May and September. The total plant investment at Oskarshamn is approximately SEK 20 billion. The village of Simpevarp is situated at the centre of the industrial site. Some of the 18th century houses in the village have been reverentially restored by OKG. The buildings and houses are now used as accommodation for visitors, for conferences, for education, company health care and information purposes.