The blast in reactor No. 3 at the Fukushima Dai-ichi plant injured 11 workers and was so large it could be felt 25 miles away.
Experts said the thick steel container protecting the reactor core was undamaged, and the plant’s operator said radiation levels outside facility remained within legal limits.
But the U.S. Navy’s 7th Fleet, stationed more than 100 miles away to help the earthquake victims, sailed further away from the stricken plant after detecting unusual levels of radioactivity in the air.
Seventeen chopper crewmen who flew through the radioactive plume generated by the plant were found to have been contaminated and had to be scrubbed down.
He said the NRC sent two nuclear experts to Tokyo to help deal with the damaged reactors.
“It is a serious situation and we continue to provide whatever assistance is requested,” he said.
Jaczko said American plants are built to withstand tornadoes, earthquakes and tidal waves, but ducked a question about whether they could survive an 8.9-magnitude quake like the one that devastated northeastern Japan Friday.
Fukushima Dai-ichi’s three reactors were damaged by the monster quake, and then the plant’s cooling systems and backup generators were wiped out by the tsunami.
A partial meltdown is already believed to have taken place inside reactor No. 1, which blew up Saturday, but radiation has been contained.
Scientists have been flooding the reactors with seawater to try to cool them – a last-ditch effort because salt water corrodes the equipment.
A third reactor – No. 2 – is also now experiencing severe problems after its uranium fuel rods became fully exposed, which is likely to lead to overheating and yet another explosion, officials said.
A fire pump that was injecting seawater into the reactor ran out of fuel, reports said.
More than 180,000 people have been evacuated from areas around the plant and 160 were reported to have suffered radiation exposure.
Japan’s Chief Cabinet Secretary Yukio Edano said “the possibility of a large amount of radioactive material being dispersed from there is low.”
In Vienna, International Atomic Energy Agency head Yukiya Amano sought to reassure the word. “The possibility that the development of this accident into one like Chernobyl is very unlikely,” Amano said.
President Obama said the U.S. is prepared to offer all necessary aid. “We will stand with Japan in the difficult days ahead,” he said.
Meanwhile, a tide of bodies washed up along the coast of Miyagi Prefecture, one of the hardest hit by the towering tsunami wave.
The official death toll has risen tenfold to 10,000 and is expected to climb.
Officials in one town said they were running out of body bags.
“We have requested funeral homes across the nation to send us many body bags and coffins. But we simply don’t have enough,” said Hajime Sato, an official in Iwate Prefecture, which was also heavily hit.
In the city of Soma, the crematorium was unable to handle the crush of bodies being brought for funerals.
“We have already begun cremations, but we can only handle 18 a day. We are overwhelmed and are asking other cities to help us deal with bodies,” said Katsuhiko Abe.
Millions of survivors were forced to cope without water, food or heating in near freezing temperatures, as rescue crews struggled with the scope of the disaster.
“People are surviving on little food and water. Things are simply not coming,” said Sato.
Aftershocks continued to rock the country, with a 6.2-magnitude quake Monday triggering a second tsunami scare.
The Japanese stock market plunged a dramatic 6% Monday, its first day opening since the disaster, on the likelihood of huge losses at Japanese industrial giants.