JOIN USJapan N-crisis critical
Japanese officials struggled on Sunday to contain a widening nuclear crisis in the aftermath of a devastating earthquake and tsunami, saying they presumed that partial meltdowns had occurred at two crippled reactors and that they were bracing for a second explosion, even as they faced serious cooling problems at four more reactors.
The emergency appeared to be the worst involving a nuclear plant since the Chernobyl disaster 25 years ago.
More than 2,00,000 people were evacuated from danger zones around two atomic facilities in Fukushima, about 240 km north of Tokyo.
Japanese officials reported that 19 people showed signs of radiation exposure and as many as another 141 were feared to have been exposed, including some who had been outside the plant waiting to be evacuated. Three workers are suffering from full-on radiation sickness.
Officials said they had also ordered up the largest mobilisation of their Self-Defence Forces since World War II to assist in the relief effort
Prime Minister Naoto Kan told a press conference late Sunday: “I think that the earthquake, tsunami and the situation at our nuclear reactors makes up the worst crisis in the 65 years since the war. If the nation works together, we will overcome.”
On Saturday, Japanese officials took the extraordinary step of flooding the crippled No. 1 reactor at Fukushima Daiichi Nuclear Power Station with seawater in a last-ditch effort to avoid a nuclear meltdown. That came after an explosion caused by hydrogen that tore the outer wall and roof off the building housing the reactor, although the steel containment of the reactor remained in place. Then on Sunday, cooling failed at a second reactor - No. 3 - and core melting was presumed at both, said the top government spokesman, Chief Cabinet Secretary Yukio Edano. An explosion could also rock the No 3 reactor, Edano warned, because of a build-up of hydrogen within the reactor.
“The possibility that hydrogen is building up in the upper parts of the reactor building cannot be denied. There is a possibility of a hydrogen explosion,” Edano said. He stressed that as in the No 1 unit, the reactor’s steel containment would withstand the explosion. “It is designed to withstand shocks,” he said.
NHK, Japan’s public broadcaster, flashed instructions to evacuees: close doors and windows; place a wet towel over the nose and mouth; cover up as much as possible. At a news conference, Edano called for calm. “If measures can be taken, we will be able to ensure the safety of the reactor,” he said.
Even before Edano’s statement on Sunday, it was clear from the radioactive materials turning up in trace amounts outside the reactors that fuel damage had occurred. The existence or extent of melting might not be clear until workers can open the reactors and examine the fuel, which could be months from now. The Japanese Nuclear and Industrial Safety Agency said that as many as 160 people may have been exposed to radiation around the plant.
Officials also said they would release steam and inject water into a third reactor at the Fukushima Daiichi plant after temperatures rose and water levels fell around the fuel rods.
Cooling had failed at three reactors at a nuclear complex nearby, Fukushima Daini, although he said conditions there were considered less dire. With high pressure inside the reactors at Daiichi hampering efforts to pump in cooling water, plant operators had to release radioactive vapor into the atmosphere. Radiation levels outside the plant, which had retreated overnight, shot up to 1,204 microsieverts per hour, or over twice Japan's legal limit, Edano said.
On Saturday, officials said they had detected radioactive cesium, which is created when uranium fuel is split, a sign that the fuel in the reactor was already damaged.
How much damage the fuel suffered remained uncertain, though safety officials insisted repeatedly through the day that radiation leaks outside the plant remained small and did not pose a major health risk.
However, they also told the IAEA that they were making preparations to distribute iodine, which helps protect the thyroid gland from radiation, to people living near Daiichi and Daini.
Northern Japan relies heavily on nuclear power for its electricity, and the government said it was instituting a series of rolling blackouts across the country starting Monday.