Japan: Helicopters drop water on overheating reactors

Engineers rush against time to cool nuclear reactors; low radioactivity seen heading towards North America; Washington increasingly worried about Japan's nuclear crisis.

Japan nuclear explosion 311 (photo credit: REUTERS/NTV via Reuters TV)
Japan nuclear explosion 311
(photo credit: REUTERS/NTV via Reuters TV)
Operators of a quake-crippled nuclear plant in Japan dumped water on overheating reactors on Thursday while the United States expressed growing alarm about leaking radiation and said it was chartering aircraft to help Americans leave the country.
Engineers were rushing against time to run in a power line off the main grid to fire up the water pumps needed to cool two reactors and the spent fuel rods considered most at risk.
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Also on Thursday, a Swedish official said that low concentrations of radioactive particles are heading eastwards from Japan's disaster-hit nuclear power plant towards North America.
Lars-Erik De Geer, research director at the Swedish Defence Research Institute, a government agency, was citing data from a network of international monitoring stations.
He stressed that the levels were not dangerous for people.
While Japanese officials were scrambling with a patchwork of fixes at the facility, the top US nuclear regulator warned that reactor No.4's cooling pool for spent fuel rods may have run dry and another was leaking.
"There is no water in the spent fuel pool and we believe that radiation levels are extremely high, which could possibly impact the ability to take corrective measures," Gregory Jaczko, head of the Nuclear Regulatory Commission, told a US House Energy and Commerce subcommittee hearing.
"It would be very difficult for emergency workers to get near the reactors. The doses they could experience would potentially be lethal doses in a very short period of time."
The plant operator said it believed the No.4 reactor spent fuel pool still had water as of Wednesday.
US officials took pains not to criticize the Japanese government, which has shown signs of being overwhelmed by the crisis, but Washington's actions indicated a divide with the Japanese about the perilousness of the situation.
"The worst-case scenario doesn't bear mentioning and the best-case scenario keeps getting worse," Perpetual Investments said in a note on the crisis.
Japan said the United States would fly a high-altitude drone over the stricken complex to gauge the situation, and had offered to send nuclear experts.
A State Department official said flights would be laid on for Americans to leave and family of embassy staff had been authorised to leave if they wanted.
Markets swoon, G7 ministers to hold emergency call
A stream of gloomy warnings and reports on the Japan crisis from experts and officials around the world triggered a sharp fall in US financial markets, with all three major stock indexes slumping on fears of slower worldwide growth.
In a sign of the degree of concern among top policymakers, one G7 central banker, who asked not to be identified, said he was "extremely worried" about the wider effects of the crisis in Japan, the world's third-largest economy.
"I think the world economy is going to go right down and it has happened at a time when financial markets are still very fragile," he said.
G7 finance ministers will hold a conference call later on Thursday to discuss steps to help Japan cope with the financial and economic impact of the disaster, a source said.
Bid to get power restored to reactors
Japan's nuclear agency said radiation levels at the plant "continued to fall", but the government appealed to private companies to help deliver supplies to tens of thousands of people evacuated from a 30-km (18-mile) zone around the complex.
Tokyo Electric Power Co. (TEPCO) officials said bulldozers attempted to clear a route to the reactor so fire trucks could gain access and try to cool the facility using hoses.
High radiation levels on Wednesday prevented a helicopter from dropping water into No. 3 to try to cool its fuel rods after an earlier explosion damaged its roof and cooling system.
Another attempt on Thursday appeared to be partially successful, with two of four water drops over the site hitting their mark. The giant, twin-blade aircraft have to make precisely timed flyovers and drops to avoid the brunt of the radiation.
Embassies urge citizens to leave
Scores of flights to Japan have been halted or rerouted and air travelers are avoiding Tokyo for fear of radiation.
On Thursday, the US embassy in Tokyo urged citizens living within 50 miles (80 km) of the Daiichi plant to evacuate or remain indoors "as a precaution", while Britain's foreign office urged citizens "to consider leaving the area".
The warnings were not as strong as those issued earlier by France and Australia, which urged nationals in Japan to leave the country. Russia said it planned to evacuate families of diplomats on Friday.
At its worst, radiation in Tokyo has reached 0.809 microsieverts per hour this week, 10 times below what a person would receive if exposed to a dental x-ray. Early on Thursday, radiation levels were barely above average.
But many Tokyo residents stayed indoors, usually busy streets were nearly deserted and many shops and offices were closed.
One bank, Mizuho , said all its automatic teller machines in the country briefly crashed. It doubted the problem was connected to the earthquake or power cuts, but it triggered a rush to withdraw cash from machines in the capital.