IAEA chief: Japan nuclear incident 'grave, serious'

Yukiya Amano says Japan racing against clock to cool overheating reactors; US says it could take weeks to cool Tokyo facility's fuel rods.

Japan Nuclear Plant 311 (R) (photo credit: REUTERS)
Japan Nuclear Plant 311 (R)
(photo credit: REUTERS)
The crisis at Japan's Fukushima Daiichi nuclear power plant is "grave and serious", Yukiya Amano, head of the UN's nuclear watchdog, said on Friday. He went on to say that Japan is racing against the clock to cool overheating nuclear reactors.
Amano returned to his native Japan and said he will not visit the plant, but that a team of scientists will go in its general direction.
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Japanese engineers toiled frantically to avert a catastrophic release of radiation from a crippled nuclear power plant north of Tokyo on Friday, but the United States said it could take weeks to cool the facility's overheating fuel rods.
Officials said they hoped to fix a power cable to at least two of the six reactors in the hope of restarting water pumps and were preparing to douse them in the afternoon with water from fire trucks.
However, no one was holding out hope that the crisis -- about to enter its second week after last Friday's 9.0-magnitude earthquake and tsunami -- could be overcome anytime soon.
Japan's nuclear agency spokesman conceded that a "Chernobyl solution" of burying the reactors in sand and concrete was in the back of the authorities' minds.
Millions in Tokyo remained indoors on Friday, fearing a blast of radioactive material from the complex 240 km (150 miles) to the north, though prevailing winds would likely carry contaminated smoke or steam away from the densely populated city to dissipate over the Pacific Ocean.
Japan's nuclear disaster, the world's worst since Chernobyl in Ukraine 25 years ago, has triggered alarm and reviews of safety at atomic power plants around the globe.
The United States' top nuclear regulator said it could take weeks to reverse the overheating of fuel rods at the Fukushima Daiichi plant.
"This is something that will take some time to work through, possibly weeks, as you eventually remove the majority of the heat from the reactors and then the spent-fuel pools," Nuclear Regulatory Commission Chairman Gregory Jaczko told a news conference at the White House.
Cooling pumps may not work
Even if the engineers manage to connect the power at the Fukushima Daiichi plant, it is not clear the pumps will work as they may have been damaged in the earthquake or subsequent explosions and there are real fears of the electricity shorting and causing another explosion.
Nuclear agency spokesman Hidehiko Nishiyama said it was unclear how effective spraying water on the reactors from helicopters had been on Thursday, but the priority now was to get water into the spent-fuel pools.
"We have to reduce the heat somehow and may use seawater," he told a news conference. "We need to get the reactors back online as soon as possible and that's why we're trying to restore power to them."
Jaczko said the cooling pool for spent-fuel rods at the complex's reactor No.4 may have run dry and another was leaking.