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[cnn-photo-caption image=http://i2.cdn.turner.com/cnn/2011/images/03/16/t1larg.japan.woman.afp.gi.jpg caption="A woman makes her way through earthquake and tsunami rubble Wednesday in Kamaishi, Japan." width=300 height=169]
Editor's note: Tune in to AC360° tonight beginning at 10pm ET to get the latest from Anderson Cooper and CNN's team of correspondents and producers on the ground in Japan.
A dire warning on the Japanese nuclear crisis is not coming from Tokyo, instead from Washington. Spent fuel rods in the No. 4 reactor of Japan's Fukuskima Daiichi nuclear plant have been exposed, leading to "very high radiation levels" near the facility, the head of the U.S. Nuclear Regulatory Commission said.
"What we believe at this time is that there has been a hydrogen explosion in this unit due to an uncovering of the fuel in the fuel pool," Gregory Jackzo told a House committee today.
But the Japanese government said radiation levels detected in the surrounding neighborhoods don't pose an immediate health risk. Only residents within 12 miles of the plant were evacuated as precaution. The U.S. is taking a more cautious approach, recommending Americans living within 50 miles to evacuate or stay indoors.
Just moments ago, a helicopter dumped water on one of the reactors, as crews try to lower the temperatures at the site. The rare tactic was aborted today when a chopper would have had to fly into steam rising from the plant.
Meanwhile, a freezing temperatures and snow are hampering search efforts in northeast Japan, where thousands remain missing.
For the survivors, in some areas, the food is running out. The U.S. military is helping the hungry by delivering more than 7,000 pounds of food and water in the disaster zone.
So far, $25 million has been donated to nonprofit organizations in Japan, according to the Chronicle of Philanthropy. To see how you can help the Japan go to our Impact Your World web page.
Richard Roth, Joe Vaccarello and Kiran Khalid
United Nations (CNN) - The U.N. Security Council showed unity by sharing in a moment of silence for the people of Japan, but then went behind closed doors divided over a no-fly zone to protect rebels fighting Moammar Gaddafi in Libya.
After Wednesday's deliberations ended, the U.S. ambassador to the United Nations told reporters that diplomats were looking at a "broad range of actions that would protect civilians," not just a no-fly zone. Envoys are keenly aware of the "urgency and gravity of the situation on the ground," Susan Rice said. They are discussing range of "serious" actions, she continued, including but not limited to a cease-fire or a no-fly zone, which "has inherent limitations in terms of protecting civilians."
Rice said she hoped diplomats would be in a position to vote on a "serious resolution" as early as Thursday.
CNN Wire Staff
Tokyo (CNN) - Spent fuel rods in Unit 4 of Japan's stricken Fukushima Daiichi nuclear plant have been exposed, resulting in the emission of "extremely high" levels of radiation, the head of the U.S. Nuclear Regulatory Commission said Wednesday.
"What we believe at this time is that there has been a hydrogen explosion in this unit due to an uncovering of the fuel in the fuel pool," Gregory Jaczko told a House energy and commerce subcommittee hearing. "We believe that secondary containment has been destroyed and 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."
The water served to both cool the uranium fuel and shield it. But once the uranium fuel was no longer covered by water, its zirconium cladding that encases the fuel rods heated, generating hydrogen, said Robert Alvarez, senior scholar at the Institute for Policy Studies and a former official with the Department of Energy.
That caught fire, resulting in a situation that is "very, very serious," he told CNN. He said the next solution may involve nuclear plant workers having to take heroic acts. Asked to be more specific, he said, "This is a situation where people may be called in to sacrifice their lives. ... It's very difficult for me to contemplate that but it's, it may have reached that point."
Photographs of the building released Wednesday by the power company showed a hole in a wall and deterioration of the roof.
A Japanese Self-Defense Force helicopter aborted its mission to drop water over the reactor because of the high radiation levels in the area, Japanese public broadcaster NHK reported.
Officials have been working to resolve cooling problems at four of Fukushima Daiichi's six reactors in the wake of the 9.0-magnitude earthquake and tsunami that devastated northeast Japan Friday.
Ready for today's Beat 360°? Everyday we post a picture you provide the caption and our staff will join in too. Tune in tonight at 10pm to see if you are our favorite! Here is the 'Beat 360°' pic:
Justin Beiber unveils his wax likeness at Madame Tussauds on March 15, 2011 in London, England. (Photo credit: Gareth Cattermole/Getty Images)
Update: Beat 360° Winners:
"No, I'm the real Justin Bieber!"
Kalon, Guelph CANADA
"One is still too young to shave and the other just waxes."
(CNN) - As the rest of the world waits to see if Japan can avert a nuclear catastrophe, a small band of experts is putting their lives at risk to prevent the disaster.
Thousands of people living near the troubled Fukushima Daiichi nuclear power plant have been evacuated from their homes because of the risk of radiation leaks from reactors damaged by last week's devastating earthquake and tsunami.
But while most hurry in the opposite direction, about 180 plant workers are staying put - despite the fact that doing so could result in serious illness or even death - to battle the meltdown threat.
"The workers at this site are involved in a heroic endeavor," former U.S. Department of Energy Official Robert Alvarez told CNN.
"There is at least fragmentary evidence that in some places on this site there are life-threatening doses of radiation. I think they are doing enormously heroic work."
The workers left at the site are said to be highly trained and experienced nuclear operators, engineers and safety staff with highly specialized knowledge.
Richard Wakeford, of the Dalton Nuclear Institute at the University of Manchester, said for many of them - despite the highly unusual and potentially dangerous circumstances - it will be just another day at the office.
CNN Wire Staff
Manama, Bahrain (CNN) - Security forces in Bahrain stormed the main hospital, beating doctors, and attacked demonstrators in Manama's Pearl Roundabout on Wednesday, witnesses in the Bahraini capital said. Bahraini officials deny these accounts.
Demonstrators reported hearing steady rounds of ammunition being fired while thick smoke rose from the Pearl Roundabout area. At least five helicopters whirred above the historic landmark, which has been a rallying spot for anti-government demonstrators in recent weeks.
In a statement Wednesday, Bahrain's government said that as police approached the roundabout, they were attacked by protesters - whom they call "saboteurs" - who threw Molotov cocktails at them. Police dispersed the protesters with tear gas, as protesters set fire to tents and trash cans on their way out, the government said.
According to the government, no live ammunition was used, and the only fatalities were two police officers who were repeatedly run over by three vehicles driven by protesters. Three arrests were made, an interior ministry spokesman said.
The crackdown comes a day after Bahrain's King Hamad imposed a three-month state of emergency and two days after Saudi Arabia and the United Arab Emirates dispatched troops to the Persian Gulf island nation to "protect the safety of citizens," the Bahraini government said.