Tokyo - Japan raced to avert a catastrophe on Wednesday after an explosion at an earthquake-crippled nuclear power plant sent radiation wafting into Tokyo, prompting some people to flee the capital and others to stock up on essential supplies.
The crisis escalated late on Tuesday when operators of the facility said one of two blasts had blown a hole in the building housing a reactor, which meant spent nuclear fuel was exposed to the atmosphere.
Prime Minister Naoto Kan urged people within 30km of the facility - a population of 140 000 - to remain indoors, as Japan grappled with the world's most serious nuclear accident since the Chernobyl disaster in Ukraine in 1986.
Officials in Tokyo - 240km to the south of the plant - said radiation in the capital was 10 times normal at one point but not a threat to human health in the sprawling high-tech city of 13 million people.
Toxicologist Lee Tin-lap at the Chinese University of Hong Kong said such a radiation level was not an immediate threat to people but the long-term consequences were unknown.
“You are still breathing this into your lungs, and there is passive absorption in the skin, eyes and mouth and we really do not know what long-term impact that would have,” Lee told Reuters by telephone.
Around eight hours after the explosions, the United Nations weather agency said winds were dispersing radioactive material over the Pacific Ocean, away from Japan and other Asian countries.
As concern about the crippling economic impact of the nuclear and earthquake disasters mounted, Japan's Nikkei index fell as much as 14 percent before ending down 10.6 percent, compounding a slide of 6.2 percent the day before. The two-day fall has wiped $620-billion off the market.
On Wall Street, stock in General Electric, the largest US conglomerate, fell nearly four percent on concern the crisis will cost it tens of billions of dollars in lost sales and potential legal costs or even liability over its nuclear technology.
Authorities have spent days desperately trying to prevent the water which is designed to cool the radioactive cores of the reactors from running dry, which would lead to overheating and the release of dangerous radioactive material into the atmosphere.
They said they may use helicopters to pour water on the most critical reactor, No. 4, within two or three days, but did not say why they would have to wait to do this.
“The possibility of further radioactive leakage is heightening,” a grim-faced Kan said in an address to the nation.
“We are making every effort to prevent the leak from spreading. I know that people are very worried but I would like to ask you to act calmly.” - Reuters