"There is no doubt that unlike in the past, the figures are the level at which human health can be affected," said chief government spokesman Yukio Edano.

Tens of thousands have already been evacuated from a zone within a radius of 20 km from the Fukushima No.1 plant, 250 kilometres (155 miles) northeast of Tokyo.

But Prime Minister Naoto Kan urged people living within 10 km of the exclusion zone around the plant to stay indoors.

Early Tuesday a blast hit the number-two reactor there. And Edano later said there was also an explosion which started a fire at the number-four reactor.

Although the number-four reactor was shut for maintenance when the quake and tsunami struck last Friday, "spent nuclear fuel in the reactor heated up, creating hydrogen and triggered a hydrogen explosion".

He said radioactive substances were leaked along with the hydrogen.

"Please keep in mind that what is burning is not nuclear fuel itself," Edano said. "We'll do our best to put out or control the fire as soon as possible." Similar hydrogen blasts had hit the number-one and number-three reactors on Saturday and Monday. Buildings housing four of the six reactors at the plant, which opened in 1971, have now been hit by explosions.

Edano said radioactive substances might spread outside the 20-30 km area but would dissipate the farther they spread.

It was still unclear whether the container sealing the number-two reactor had been breached.

The plant operator initially told the nuclear safety agency that it had not been holed, but later told AFP it was still checking for any breach.

Japan is frantically battling a nuclear emergency after Friday's massive earthquake and tsunami cut power to the 40-year-old plant and knocked out cooling systems.

Officials have struggled to prevent meltdowns at the damaged reactors, saying fuel rods may have been critically damaged by overheating.

But they have not reported the kind of radiation leakage that would accompany a major meltdown.

The continuing nuclear crisis has unnerved regional residents already struggling with the aftermath of the quake and tsunami.

"There are very few people out in the streets", said Mako Sato, a cafe waitress in the town of Miharumachi just outside the evacuation zone. "They are either staying at home or in the evacuation centres.

"Since conditions surrounding the nuclear plant are so uncertain, I am worried. Food supplies are low and all that customers talk about is the quake and how scary it is, because we still feel aftershocks."

An employee at the Hotel Chisun in Koriyama said there were no visible signs of panic despite the nuclear crisis.

"Everyone is reacting calmly. But due to safety concerns after the quake we aren't accepting new business," the employee said. "

"There is very little food and convenience stores nearby are all closed. We are doing the best we can with our reserves."

earlier related report
New blast, fire at nuke plant in disaster-hit Japan
Sendai, Japan (AFP) March 15, 2011 - Japan's nuclear crisis deepened Tuesday as a third blast and a fire rocked a stricken atomic power plant, sending radiation up to alarming levels, after a quake-tsunami catastrophe.

Radiation levels around the Fukushima No.1 plant on the eastern coast have "risen considerably", Prime Minister Naoto Kan said, and his chief spokesman said the level was now considered high enough to endanger human health.

Kan told people living up to 10 kilometres (six miles) beyond a 20km (12-mile) exclusion zone around the nuclear plant to stay indoors.

The fire was burning in the plant's number-four reactor, he said, meaning that four out of six reactors at the site 250 kilometres (155 miles) northeast of Tokyo are now in trouble.

As well as the atomic emergency, Japan is struggling to cope with the enormity of the damage from Friday's record-breaking quake and the tsunami which raced across vast tracts of its northeast, destroying all before it.

The official death toll has risen to 2,414, police said Tuesday, but officials say at least 10,000 are likely to have perished.

A huge explosion rocked the ageing Fukushima facility shortly after dawn Tuesday, the third since Friday as engineers struggle to control overheating reactors.

Japan's nuclear safety agency said the operator of the stricken plant believed the seal around the reactor, which is critical for preventing a major radiation leak, had not been holed and was doing further checks.

But Kan's top spokesman Yukio Edano said there appeared to be damage to the structure around the number-two reactor, the third to be hit by an explosion since Friday's disaster which knocked out cooling systems.

Edano, who is the chief cabinet secretary, told reporters there could be damage to the suppression pool of the reactor, which forms the base of the container vessel that seals the fuel rods.

Plant operator Tokyo Electric Power Co. (TEPCO) "said it believes the container vessel has not sustained damage such as a hole, judging from the fact that the radiation level has not jumped", a safety agency spokesman told AFP.

TEPCO said some workers had been evacuated from the number-two reactor at the plant, but those pumping water to cool the reactor were still at work.

Higher radiation levels were earlier recorded in Ibaraki prefecture north of Tokyo after the the blast, Kyodo News reported, but it quoted the safety agency as saying that the level did not pose health risks.

On Saturday an explosion blew apart the building surrounding the plant's number-one reactor but the seal around the reactor itself remained intact, officials said.

On Monday, a blast at its number-three reactor shook the facility, injuring 11 people and sending plumes of smoke billowing into the sky.

Late Monday TEPCO said fuel rods at the number-two reactor were almost fully exposed after a cooling pump there temporarily failed.

The UN's nuclear watchdog, the International Atomic Energy Agency, said Tokyo had asked for expert assistance in the aftermath of the quake which US seismologists are now measuring at 9.0-magnitude, revised up from 8.9.

But the IAEA's Japanese chief Yukiya Amano moved to calm global fears that the situation could escalate to rival the world's worst nuclear crisis at Chernobyl in the Ukraine in 1986.

"Let me say that the possibility that the development of this accident into one like Chernobyl is very unlikely," he said.

Officials had already declared the exclusion zone within a 20-km radius of the plant and evacuated 210,000 people.

At one shelter, a young woman holding her baby told public broadcaster NHK: "I didn't want this baby to be exposed to radiation. I wanted to avoid that, no matter what."

Further north in the region of Miyagi, which took the full brunt of Friday's terrifying wall of water, rescue teams searching through the shattered debris of towns and villages have found 2,000 bodies.

And the Miyagi police chief has said he is certain more than 10,000 people perished in his prefecture.

Millions have been left without water, electricity, fuel or enough food and hundreds of thousands more are homeless and facing harsh conditions with sub-zero temperatures overnight, and snow and rain forecast.

Tokyo stocks, which were punished Monday when the markets reopened, sending indexes around the world sliding, plummeted another 6.45 percent by Tuesday's lunch break.

Panic selling saw stocks close more than six percent lower in Tokyo Monday on fears for the world's third-biggest economy, as power shortages prompted rolling blackouts and factory shutdowns in quake-hit areas.

Kaori Ohashi, 39, a mother-of-two working in a nursing home for the elderly near the city of Sendai, spent two nights trapped in the building after its first floor was submerged by the tsunami.

"Snow started to fall and it became dark. We lost power. I thought 'This is a nightmare'," Ohashi told AFP after she was rescued.

At least 1.4 million people in Japan were temporarily without running water and more than 500,000 were taking shelter in evacuation centres, said the UN's Office for the Coordination of Humanitarian Affairs.

At a hospital in the fishing town of Kesennuma hit by the tsunami, an official said basic supplies were desperately needed.

"We are critically short of water," he said. "Water is very important here. To save it, we need a lot of disposable dishes. We need blankets as well."

Aid workers and search teams from across the world joined 100,000 Japanese soldiers in a massive relief push as the country suffers a wave of major aftershocks.

The foreign ministry expressed its "heartfelt appreciation" for offers of help pouring in from around the world, and said rescue teams from 11 countries including China -- Japan's traditional rival -- were now on the ground.

With ports, airports, highways and manufacturing plants shut down, the government has predicted "considerable impact on a wide range of our country's economic activities".

Leading risk analysis firm AIR Worldwide said the quake alone would exact an economic toll estimated at between $14.5 billion and $34.6 billion (10 billion to 25 billion euros) -- even leaving aside the effects of the tsunami.

burs-lb/jit

del.icio.us	Digg	Reddit
YahooMyWeb	Google	Facebook

Memory Foam Mattress Review

SPACE MEDIA NETWORK PROMOTIONS Solar Energy Solutions Tempur-Pedic Mattress Comparison ... Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News