Japan - High levels of radiation leaked from a crippled nuclear plant in tsunami-ravaged northeastern Japan after a third reactor was rocked by an explosion Tuesday and a fourth caught fire in a dramatic escalation of the 4-day-old catastrophe. The government warned 140,000 people nearby to stay indoors to avoid exposure.
Japan’s nuclear crisis verged toward catastrophe on Tuesday after an explosion damaged the vessel containing the nuclear core at one reactor and a fire at another spewed large amounts of radioactive material into the air, according to the statements of Japanese government and industry officials.
In a brief address to the nation at 11 a.m. Tokyo time, Prime Minister Naoto Kan pleaded for calm, but warned that radiation had already spread from the crippled reactors and there was “a very high risk” of further leakage. Fortunately, the prevailing winds were sweeping most of the plume of radioactivity out into the Pacific Ocean, rather than over populated areas.
Readings reported on Tuesday showed a spike of radioactivity around the plant that made the leakage categorically worse than in had been, with radiation levels measured at one point as high as 400 millisieverts an hour.
Even 7 minutes of exposure at that level will reach the maximum annual dose that a worker at an American nuclear plant is allowed. And exposure for 75 minutes would likely lead to acute radiation sickness.
The cascade of problems at Daiichi was initially difficult to interpret — with confusion compounded by incomplete and inconsistent information provided by government officials and executives of the plant’s operator, Tokyo Electric Power.
But industry executives in close contact with officials in Japan said that the chain of events at Daiichi suggested that the authorities had come close to losing control of the situation, and that it would be difficult to maintain emergency seawater cooling operations at stricken reactors if a fire at a fourth reactor nearby was releasing large amounts of radioactive material — at least without threatening the health of emergency workers onsite.
The problem at the fourth reactor had not been reported before late Tuesday morning. According to officials, a fire broke out at that reactor, which had been offline at the time of the earthquake but was storing spent nuclear fuel.
“Tokyo Electric has not been able to cool” the spent fuel pools at its two troubled nuclear plants, Daiichi and Daini, because power has been knocked out, said Johei Shiomi, a spokesman for the company.
“There may be some heating up,” he said.He also said water had spilled out from the pools, which lie close to the main reactors.Spent fuel can be as dangerous as active fuel if left uncovered for too long, experts say, though time-to-boil depends on how much fuel is present, and how old it is.
Still, Mr. Shiomi said that the company felt that there “was relatively little danger that temperatures would rise,” Mr. Shiomi said. “If you compare this to everything that’s been going on, it’s not serious,” he said. He made those comments before fire broke out at the No. 4 reactor.
Japan - The second hydrogen explosion in three days rocked Japan's stricken Fukushima Dai-ichi nuclear plant Monday, sending a massive column of smoke into the air and wounding 6 workers. The plant's operator said radiation levels at the reactor were still within legal limits.
"First I was worried about the quake," said Kenji Koshiba, a construction worker who lives near the plant. "Now I'm worried about radiation." He spoke at an emergency center in Koriyama, about 40 miles (60 kilometers) from the most troubled reactors and 125 miles (190 kilometers) north of Tokyo.
At the makeshift center set up in a gym, a steady flow of people — mostly the elderly, schoolchildren and families with babies — were met by officials wearing helmets, surgical masks and goggles.
A huge column of smoke billowed from Fukushima Daiichi's reactor 3, two days after a blast hit reactor 1.The latest explosion, said to have been caused by a hydrogen build-up, injured 11 people, one of them seriously.
Soon afterwards, the government said a third reactor at the plant had lost its cooling system.Water levels were now falling at reactor 2, which is to be doused with sea water, said government spokesman Yukio Edano.
The No 3 reactor building at the plant exploded on Monday, destroying the walls and sending a plume of white smoke into the air.But officials said the reactor remained intact, adding that there was a low possibility the blast had released radioactive material.A powerful explosion has hit a nuclear power station in north-eastern Japan which was badly damaged in Friday's devastating earthquake and tsunami.
Experts say a disaster on the scale of Chernobyl in the 1980s is highly unlikely because the reactors are built to a much higher standard and have much more rigorous safety measures.
Earlier, the prime minister said the situation at the nuclear plant was alarming, and the earthquake had thrown Japan into "the most severe crisis since World War II".The government advised people not to go to work or school on Monday because the transport network would not be able to cope with demand.
The capital Tokyo is also still experiencing regular aftershocks, amid warnings that another powerful earthquake is likely to strike very soon.
Hidehiko Nishiyama, a senior official of the Economy, Trade and Industry Ministry, indicated the reactor core in Unit 3 had melted partially, telling a news conference, "I don't think the fuel rods themselves have been spared damage," according to the Kyodo News agency.
A complete meltdown — the melting of the radioactive core — could release uranium and dangerous contaminants into the environment and pose major, widespread health risks.
Japan’s nuclear crisis verged toward catastrophe on Tuesday after an explosion damaged the vessel containing the nuclear core at one reactor and a fire at another spewed large amounts of radioactive material into the air, according to the statements of Japanese government and industry officials.
In a brief address to the nation at 11 a.m. Tokyo time, Prime Minister Naoto Kan pleaded for calm, but warned that radiation had already spread from the crippled reactors and there was “a very high risk” of further leakage. Fortunately, the prevailing winds were sweeping most of the plume of radioactivity out into the Pacific Ocean, rather than over populated areas.
