Restoration work at Fukushima nuke plant disrupted again

Work to restore power and key cooling functions was disrupted at Fukushima Daiichi nuclear plant as smoke caused workers to evacuate.

According to Kyodo News, Tokyo Electric Power Co. said it learned at around 4:20 p.m. that black smoke was seen rising at the No. 3 reactor building, leading to evacuation of workers from the four troubled reactors. An hour later the black smoke receded.

The radiation level was unchanged shortly afterward, meaning the smoke caused no massive release of radioactive materials. Smoke was also seen billowing from the No. 3 building on Monday.

It also turned out that the surface temperatures of the No. 1 and No. 3 reactor vessels have topped the maximum levels set by their designers. The rise of the temperatures came to light after data measuring instruments became available with the power restored Tuesday, the agency said.

At the plant run by the utility known as TEPCO, all six reactors were reconnected to external power as of Tuesday night and workers scrambled to check each piece of equipment, such as data measuring tools and feed-water pumps, before transmitting power to them.