Explosion in Japan nuke plant, meltdown feared

Radiation leaked from an unstable Japanese nuclear reactor north of Tokyo today after an explosion blew the roof off the facility in the wake of a massive earthquake.

The developments raised fears of a disastrous meltdown at the plant, which was damaged by yesterday's 8.9-magnitude earthquake, the strongest ever recorded in Japan.

While the government has declared an atomic emergency, it insisted radiation levels were low because although the explosion severely damaged the main building of the plant, it had not affected the reactor core container.

Television footage showed smoke billowing from the quake-hit atomic plant Fukushima No 1, about 250km northeast of Tokyo, at about 4pm Malaysian time.

State TV station NHK reported that several workers were injured in the blast and that the walls and roof of the quake-damaged nuclear plant had been destroyed.

Premier Naoto Kan has urged calm among people living around the affected power plant.

The government said the Tokyo Fire Department has sent its 'hyper rescue team' to the damaged nuclear plant. It has expanded the evacuation area around the nuclear reactor to a 20km radius from 10km.

According to NHK, at least three residents evacuated from a town near the quake-hit nuclear plant had been exposed to radiation. 

Iodine to be distributed

Meanwhile, Japanese authorities have told the UN atomic watchdog they are making preparations to distribute iodine to people living near nuclear power plants.

Iodine can be used to help protect the body from radioactive exposure. However, the government insisted that radiation levels were low.

Japan's Jiji news agency later said three workers suffered radiation exposure near the Fukushima nuclear plant.

The International Atomic Energy Agency (IAEA), the UN nuclear body, said Japanese authorities had informed it of the explosion and that they were "assessing the condition of the reactor core".

Japan expanded the evacuation zone around the plant, Fukushima Daiichi, and also that of the nearby Fukushima Daini nuclear power plant.

"The authorities also say they are making preparations to distribute iodine to residents in the area of both the plants," the IAEA said in a statement.

Desperate attempt to cool down reactor 

The blast came as plant operator Tokyo Electric Power Co (Tepco) worked desperately to reduce pressures in the core of the reactor that - if not contained - could lead to a release of radiation into the atmosphere.

"An unchecked rise in temperature could cause the core to essentially turn into a molten mass that could burn through the reactor vessel," risk information service Stratfor said in a report.

"This may lead to a release of an unchecked amount of radiation into the containment building that surrounds the reactor."

According to experts, nuclear reactors remain tremendously hot for at least two days even after they have been shut down.

"Reactors are not like your car that you can turn off and walk away. They're going to continue generating a great amount of heat until the core is disassembled.

"Without cooling water, then you stand a real chance of a meltdown of core that could result in a large release of radiation, potentially," said Ron Chesser, director for the Center of Environmental Radiation Studies at Texas Tech University.

Chesser was the first American scientist allowed inside the exclusion zone in 1992 in Ukraine following the Chernobyl disaster.

Nuclear fuel rods briefly exposed

Officials at the plant had earlier reported that part of the reactor core was exposed to air for a brief moment and that they were attempting to raise the water level to continue cooling the reactor with the help from a fire engine's pump.

Reactor cooling systems failed at two plants after yesterday's record 8.9-magnitude earthquake hit, unleashing a terrifying 10-metre high wave that tore through coastal towns and cities, destroying all in its path.

Kyodo News agency said radioactive caesium had been detected near Fukushima No 1, one of the quake-hit plants.

The cooling system of the plant was damaged in the massive earthquake that struck the region 24 hours earlier, leaving authorities scrambling to fix the problem and evacuate more than 45,000 residents within a 10-kilometre radius.

Thousands were also evacuated from near a second plant, Fukushima No 2, which also suffered damage to its cooling system.

The atomic emergency came as the country struggled to assess the full extent of the devastation wreaked by the massive tsunami, which was unleashed by the strongest quake ever recorded in Japan.

The towering wall of water pulverised the northeastern city of Sendai, where police reportedly said 200-300 bodies had been found on the coast.

Many shops are closed

Along Japan's northeast coast, rescue workers searched through the rubble of destroyed buildings, cars and boats, looking for survivors in hardest-hit areas such as the city of Sendai, 300km northeast of Tokyo.

Dazed residents hoarded water and huddled in makeshift shelters in near-freezing temperatures. Aerial footage showed buildings and trains strewn over mudflats like children's toys.

"All the shops are closed, this is one of the few still open. I came to buy and stock up on diapers, drinking water and food," Kunio Iwatsuki, 68, told Reuters in Mito city, where residents queued outside a damaged supermarket for supplies.

Across the coastline, survivors clambered over nearly impassable roads. In Iwanuma, not far from Sendai, people spelled S.O.S. out on the roof of a hospital surrounded by water, one of many desperate scenes.

The earthquake and tsunami, and now the radiation leak, present Japan's government with its biggest challenge in a generation.

The explosion at Chernobyl's nuclear plant's fourth reactor in 1986 sent thousands of tonnes of toxic nuclear dust billowing across the Ukraine, Russia and Belarus. It was the worst civil
nuclear disaster. 

Nuclear power company has rocky past  

The blast at the Japanese nuclear facility came as plant operator Tepco worked desperately to reduce pressures in the core of the reactor.

The company has had a rocky past in an industry plagued by scandal. In 2002, the president of the country's largest power utility was forced to resign along with four other senior executives, taking responsibility for suspected falsification of nuclear plant safety records.

NHK television and Jiji news agency said the outer structure of the reactor building that houses the reactor appeared to have blown off, but nuclear experts said this did not necessarily mean the nuclear reactor had been breached.

Earlier the operator released what it said was a tiny amount of radioactive steam to reduce the pressure and the danger was minimal because tens of thousands of people had already been
evacuated from the vicinity.

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