STOCKHOLM, July 30 (Xinhua) -- Unusually high sea water temperature has forced Swedish nuclear power plant to close, the Swedish Television SVT reported on Monday.

The sea water's temperature outside one of Sweden's nuclear plants has forced the plant to close down temporarily. As the sea water reached a temperature of 25 degrees Celsius, it can no longer be used for a cooling effect.

"In order for us to secure the needed cooling capacity, we have decided to take Ringhals 2 nuclear power plant out of operation," Ringhals' Production Manager Sven-Anders Andersson said in a press release quoted by SVT.

Two other nuclear power plants, Ringhals 3 and 4, are still working normally. Meanwhile, Ringhals 1 is on its annual planned maintenance.

Sea temperatures as high as this are unusual in Sweden. During the 21st century, this is the second time a nuclear power plant is closed for the same reason.