Japan faced the growing possibility of serious radiation leaks - maybe even a catastrophic meltdown - after two more explosions rocked a nuclear power plant and workers were forced to abandon the most dangerous reactor, which suffered damage to its containment structure.
The government warned Tuesday of an alarming radiation leak from the stricken nuclear power plant and told people nearby to stay indoors to avoid becoming sick in a rapidly escalating national crisis following last week's earthquake and tsunami.
Tokyo also reported slightly elevated radiation levels, but officials said the increase was too small to threaten the 39 million people in and around the capital, about 270 kilometres away.
In a nationally televised statement, Prime Minister Naoto Kan said radiation has spread from the three reactors of the Fukushima Dai-ichi nuclear plant in one of the hardest-hit provinces in Friday's 9.0-magnitude earthquake and the ensuing tsunami.
"The level seems very high, and there is still a very high risk of more radiation coming out," Mr. Kan said.
He warned there are dangers of more leaks and told people living within 30 kilometres of the Fukushima Dai-ichi complex to stay indoors to avoid radiation sickness.
Chief Cabinet Secretary Yukio Edano said a fourth reactor at the complex was on fire and more radiation had been released.
"Now we are talking about levels that can damage human health. These are readings taken near the area where we believe the releases are happening. Far away, the levels should be lower," he said.
The death toll from last week's earthquake and tsunami jumped Tuesday as police confirmed the number killed had topped 2,400, though that grim news was overshadowed by a deepening nuclear crisis. Officials have said previously that at least 10,000 people may have died in Miyagi province alone.
The rapidly deteriorating crisis raised the likelihood of more mass evacuations from the area around the plant, which sits 260 kilometres northeast of Tokyo and its metropolitan population of 30 million. Already, some 200,000 people living within 30 kilometres of the plant have been ordered to leave, although 600 people were known to be trapped in the area closest to the plant, having not heard the initial evacuation order after the earthquake and aftershocks apparently left them without communications. They were told Monday to stay inside, though some of their homes were damaged by the quake.
"It's like a horror movie," said 49-year-old Kyoko Nambu told the Associated Press as she stood on a hillside overlooking her ruined hometown of Soma, 40 kilometres from the plant. "Our house is gone and now they are telling us to stay indoors.
"We can see the damage to our houses, but radiation? ... We have no idea what is happening. I am so scared."
The explosion Tuesday morning at Fukushima No. 2 reactor occurred near a suppression pool that removes heat under a reactor vessel, plant owner Tokyo Electric Power Co. said. But it initially didn't appear the containment vessel had been breached and there were conflicting reports on whether radiation levels had increased. Only workers essential to efforts to cool the reactor were kept at the No. 2 site.
That came after hydrogen explosions Monday at the No. 3 reactor and Saturday at No. 1 destroyed the outer concrete structure, but reportedly did not damage the inner radiation containment shell or the reactor itself. On Tuesday, officials acknowledged that the containment shell of one of the nuclear reactors appeared to be damaged, indicating possible serious radiation leaks.
A top Japanese official said the fuel rods in all three of the stricken reactors at the Fukushima Daiichi plant appeared to be melting.
"Although we cannot directly check it, it's highly likely happening,"Mr. Edano told reporters.
News was coming so fast as dawn broke on Tuesday in Japan, that news anchors on state-run NHK television were frequently interrupted by colleagues handing them updates on pieces of paper.
The rods at all three reactors in the Fukushim Daiichi plant, normally kept cool by water, have been at risk of overheating since Friday's massive 9.0-magnitude earthquake and tsunami, the plant's operator, Tokyo Electric Power Co, and the Japanese government have acknowledged.
When troubles first started at Fukushima, sea water was injected into the reactor and the exposed rods were cooled. But water levels fell again Monday at the No. 2 reactor after the water pump temporarily ran out of fuel and workers failed to notice it quickly enough. It was unclear how long the reactor's volatile core lay fully exposed or to what extent it heated up in that time.
Sea water was again injected, but water levels had fallen dramatically and only one out of five fire pumps in the facility was functioning, the official Kyodo news agency reported.
Separately, the outer building encasing the No. 3 reactor went up in a small mushroom cloud Monday after a hydrogen explosion blew the roof off in a blast almost identical to the one that struck Fukushima's Reactor No. 1 in Saturday. The explosion Monday had been predicted by officials, who said afterwards that the inner building had not breached, making a complete meltdown very unlikely.
The three reactors at Fukushima Daiichi are among nine reactors in the northeast of Japan that have been in crisis. Six of the reactors are in the Fukushima area - 260 kilometres northeast of Tokyo - and three are located at the Onagawa plant, 50 kilometres north of Sendai in the area worst-affected by the tsunami.
The reactors at Fukushima Daini and the Onagawa facility have emitted higher than legal levels of radiation, but have thus far not experienced the kind of troubles suffered by Fukushima Daiichi.
"The Japanese authorities are working as hard as they can, under extremely difficult circumstances, to stabilize the nuclear power plants and ensure safety," read a statement from Yukiya Amano, head of the International Atomic Energy Agency. "The nuclear plants have been shaken, flooded and cut off from electricity. Operators have suffered personal tragedies," he said.
The expression of confidence from Mr. Amano, a former senior Japanese diplomat, echoes the line taken by the government, which has maintained throughout the four-day old crisis that a Chernobyl-style meltdown is very unlikely at any of the troubled reactors.
Nonetheless, concern over what may be taking place at Fukushima Daiichi, in particular, has sparked a quiet panic in Tokyo, where normally stoic citizens began to stock up on staples such as noodles, bread and rice. Some convenience stores opened to lineups of 40 or 50 people Monday morning, and exhausted their stores of some goods within an hour.
Fuel lineups, already commonplace in the tsunami-stricken north of the country, were seen in Tokyo Monday as well. Many commuter and long-distance train routes were out of service even as the country returned to work for the first time since the multiple crises began.
Those who live closest to Fukushima are the most concerned. "Our feeling is the government is hiding some things, that the information is not fully transparent," said Hiroko Okazaki, a 60-year-old housewife in Koriyama, the city closest to the crisis-stricken plant. "Even if some experts explain [that it is safe] they might not know the reality on the ground."
Thousands of residents of the Fukushima area have been brought to radiation clinic set up in the parking lot of a Koriyama to be tested for levels of radiation exposure. Those with high levels are given on-the-spot showers and scrubs inside an insulated tent or taken directly to hospital.
- WIth a report from the Associated Press