(Reuters) - The wind near a quake-hit nuclear complex in northeast Japan that has released radiation into the atmosphere is forecast to blow from the northwest on Thursday, moving toward the Pacific Ocean, the weather agency said.
Operators of the quake-crippled nuclear plant said they would try again on Thursday to use military helicopters to douse overheating reactors, as U.S. officials warned of a rising risk of a catastrophic radiation leak from spent fuel rods.
The wind near the plant, which is on the coast, will blow as fast as at 12 meters (39 ft) per second, the Japan Meteorological Agency in Fukushima prefecture said.
The Fukushima Daiichi plant, run by Tokyo Electric Power Co. (TEPCO), is about 240 km (150 miles) north of Tokyo on the country's northeast coast.
The plant has sent low levels of radiation wafting into Tokyo earlier this week, triggering both fear in the capital and international alarm.
Officials said radiation in Tokyo was 10 times normal at one point on Tuesday, but not a threat to human health in the sprawling high-tech city of 13 million people.
Early Thursday, radiation levels were barely above average.
But many Tokyo residents stayed indoors. Usually busy streets were nearly deserted. Many shops and offices were closed.
A massive earthquake and tsunami on Friday crippled the plant's cooling functions, forcing operator Tokyo Electric Power Co to pour sea water into the reactors, releasing radioactive air into atmosphere.
(Reporting by Yoko Nishikawa, editing by Jonathan Thatcher)