OKG's Oskarshamn 3 has reached its new maximum thermal capacity, two years later than originally anticipated. Solutions still have to be found for some of the turbine problems that contributed to the delay.
The boiling water reactor (BWR) reached its new maximum thermal capacity on 23 September, according to OKG managing director Ingemar Engkvist, and is now operating at 1450 MWe. This makes it the largest-capacity BWR in the world.
Initial approval was granted for the €313 million ($455 million) modernization program, including improvements to the reactor and turbines, in 2005. The plan saw the unit's capacity increase from 1200 MWe to 1450 MWe. It received regulatory approval for one year's trial operation at 1450 MWe in October 2009. The path to full capacity, however, has not been smooth thanks to problems with turbine equipment. These have not all been fully solved yet, the company says.
One of the issues highlighted by OKG is the plant's sensitivity to variations in the temperature of sea water used for cooling, which will be addressed during the plant's next maintenance outage. However in the meantime, the operator's focus is to complete the current program of testing so that the plant can maintain operations at full capacity, then to ensure that the plant can deliver a stable supply at the highest possible capacity through the coming winter. Last winter, OKG elected to operate the plant at only 1100 MWe rather than pushing ahead with trial operations for the sake of guaranteeing a stable electricity supply.