This follows five months of improvements at the plant located some 300 kilometres south of Stockholm. The 487-megawatt unit was shut down in August after Sweden’s Nuclear Power Inspectorate demanded all nuclear plants inspect and improve their electricity systems after two backup reactors malfunctioned during a power failure at the Forsmark nuclear power plant.
A spokesman for the nuclear watchdog said the Oskarshamn unit had shown similar defects to those at Forsmark, but that precautionary measures have now been completed.
In 1980, the government pledged to end the country’s reliance on nuclear power and 17 years later started closing down the country’s 12 reactors. Nuclear power still produces 50 percent of Sweden’s electricity.