2011年4月11日星期一

Japanese nuclear operator scrambles to avoid meltdowns

Tokyo - Japanese authorities said Sunday that efforts to the cooling system on one of the reactors from Friday damaged restart earthquake failure even as officials fought to several other damaged reactors under control to bring.

Workers Fukushima Daiichi nuclear power station have not found a way to stabilize to overheated reactors and the possibility of the partial nuclear meltdown, that could possibly cause another version of radioactive material, Japan's top Government spokesman said Sunday feared. Engineers had difficulties, in particular with two units of the nuclear facilities – from which their lost outer containment wall Saturday in an explosion.

Meanwhile, State of emergency at a nuclear power plant in Onagawa, where excessive radiation levels were reported said officials.

Chief Cabinet Secretary Yukio Edano said that a similar explosion soon in Fukushima Daiichi unit 3, the result of hydrogen levels could occur within the unit reactor vessel in the middle of last desperate efforts fuel immersed in the water rise to keep. Already, said trace amounts of radioactive material from the reactor No. 3 to have leaked Edano.

"At the risk of sensitisation of further concern to the public, we can not exclude the possibility of an explosion,", Edano said.

But Edano out that an explosion would have no impact on human health. Based on first results of the Government and Japan's nuclear agency, the Saturday explosion in unit 1 reactor not damaged the ship, and the Government said that reactor vessel would withstand the unit 3 also an explosion. The reactor, which flooded ships of no. 3 and no. 1 with sea water and boron in an emergency attempt to keep the units the main power supply and a backup system failed cool after the system lost.

Although the third unit is filled with water is, registered his gauge within the rising levels, not Edano said. He had no explanation.

"If the cooling system is not maintained, it is a good chance, begin the core could meltdown," said Masashi gota, a former Toshiba engineer, the design of the vessel containment for these nuclear reactors was involved.

Richard Lester, co-Chair of the Department of nuclear science and engineering at MIT, said: "The most important task, which have the operators - and have for last 36 hours - is the fuel in the reactor covered submerged in the water to keep." If they do, the fuel rods in the water keep covered succeeds, the likelihood of significant damage to the fuel is low. "If they can keep the fuel covered with water, then you have the option, melt."

To a 12-mile radius of the plant have about 170,000 people were evacuated. You join more than 450,000 other evacuated from other Quake and tsunami affected regions. A spokesman for Japan's nuclear agency said more than 160 people may have been exposed to radiation and is in a hospital to determine whether levels were dangerous tested.

"Only the greatest danger an evacuation in such a moment, would justify", said Peter Bradford, a former Commissioner at the nuclear regulatory Commission U.S..

Edano, said a meltdown officials acted on the assumption could be under way in Fukushima Daiichi unit 3, and that "high" could a meltdown was in progress to his unit 1 reactor, where an explosion a day earlier destroyed a building.


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