TOKYO - Firefighters postponed spraying Japan's badly damaged nuclear reactor No. 3 with seawater on Monday after a plume of grey smoke was seen over the structure, the government said.
Smoke began to rise from the plant's No.2 and No.3 reactors on Monday, just as authorities had begun to show signs of progress in its efforts to avert nuclear disaster at the site. Japan's nuclear safety agency later said the smoke had stopped rising over the reactor.
The plant operator said it did know what caused the smoke.