Fears mount as second reactor overheats

Japan battled a nuclear emergency today in which the government said two partial meltdowns may have taken place and radiation had escaped from reactors at a quake-damaged atomic power plant.About 200,000 people have been evacuated from residential areas around the Fukushima No 1 plant, 250km north of Tokyo, as global concern grows over the threat of a major disaster.Japan's top government spokesman Yukio Edano said it was highly likely that a partial meltdown had occurred in one reactor of the Fukushima plant, and that authorities were working on the assumption that one may occur in another.

Edano added that the radiation released into the air so far had not reached levels high enough to affect human health.The crisis began with Friday's massive quake and tsunami disaster, the worst on record in Japan, which caused electricity blackouts and led to malfunctions of the cooling systems of the plant's reactors. Authorities immediately declared a nuclear emergency and have since scrambled to prevent reactors at two plants from overheating by pumping in water and releasing steam to depressurise them.Operator Tokyo Electric Power (TEPCO) took the drastic measure of using sea water to cool reactor one - where a huge explosion yesterday tore away the outer concrete housing while leaving the steel reactor intact.

The use of freely available, but corrosive seawater is seen as a desperate step and an admission that the reactor will never again be operational.On Sunday, the operator warned that another reactor, No 3, was also overheating and that so much water had evaporated at one stage that the top three metres of mixed oxide (MOX) fuel rods were exposed to the air.A Tepco spokesman later told AFP that the rods were covered again.Edano said the pressure build-up at reactor No 3 had forced another release of vapour to depressurise the facility and that "we assume that a minute amount of radioactivity was released".

Nuclear plant operators must alert the government when the hourly level of radioactivity reaches 500 micro sievert - and Edano said the level had topped 1,200 this morning.Edano later warned of the risk that the building around reactor No 3 could also explode, but voiced confidence that the reactor would also survive and that there would be no adverse effect on the health of nearby residents.The government has evacuated people from a 20km radius around the facility - while also moving people out of areas surrounding a second nearby plant, Fukushima No 2, which has four reactors.

22 hospitalised for exposure to radiation

A total of 22 people have been hospitalised after being exposed to radioactivity, although it was not immediately clear to what degree they were exposed and what condition they were in.In the city of Fukushima, set amid mountains some 80km northwest of the seaside plants, fears of a greater emergency grew, and people rushed to stock up on supplies. Petrol stations had already run dry.Hundreds joined orderly queues outside a co-op market where shop assistants wore surgical masks and overalls, and shoppers came out carrying as many bottles of water, groceries and other supplies as they could.

Naruki Ono, 40, who had travelled for 40 minutes to reach the town, said: "People are nervous. People are not panicked, but nuclear plants are scary. The bottom line is: I will pray that the nuclear plant doesn't explode."Early today the country's nuclear safety agency rated the accident at four on an international scale from 0 to 7. The 1979 Three Mile Island accident in the United States was rated five while the 1986 Chernobyl disaster was a seven.But an official warned the rating might change as the situation developed.

Japan's centre-left Prime Minister Naoto Kan, who was battling opinion poll ratings below 20 percent before the disaster struck, faced media criticism on Sunday over his government's response to the nuclear crisis. The Yomiuri Shimbun daily noted that it took five hours for the government to publicly address fears about a nuclear meltdown after the blast yesterday, while an Asahi Shimbun headline charged: "Crisis management all mixed up".


Source : http://www.malaysiakini.com/news/158514