Sunday, March 27, 2011

A highly radioactive pollution detected off Fukushima

Work is continuing at the center of Fukushima, Saturday, March 26, but they were further hampered by the discovery of radioactive spills in three of the six reactors. Three technicians have suffered burns after being exposed to the reactor No. 3 at a level of radioactivity 10 000 times higher than normally measured in such a place, according to the agency which manages the plant, TEPCO.

In total, nearly 700 people took turns to try to stabilize the reactor of the plant for several weeks in vain. The discovery of radioactive spills, which should be lifted as soon as possible according to the Nuclear Safety Agency of Japan, is just the latest incident in a long series since the earthquake that hit north of the island, 11 March, killing at least 10,151 dead and 17,053 missing.

Japanese Prime Minister, Naoto Kan, acknowledged this weekend that the evolution of the situation remained "unpredictable". TEPCO, which connected the reactors to power cables, believes that the operations will last at least another month. Two of the six reactors are not a priori more danger but the other four are not yet stabilized and occasionally emit steam and smoke.

Still, the Japanese Nuclear Safety Agency said the temperature and pressure had stabilized in all reactors. In Vienna, the International Atomic Energy Agency (IAEA) held that the situation had barely changed over the last 24 hours and "there are still uncertainties, highly disturbing." U.S.

experts have, however, wanted reassurance against fears of a rupture of the seal of one or more reactors at the plant, saying that the worst scenario is perhaps not as bad as you might expect. "If rupture of the reactor vessel (No. 3) and the containment may be delayed much longer, the radioactivity of the nuclear fuel will be reduced accordingly," said Friday during a press conference Edwin Lyman , a physicist at the Union for Concerned Scientists, an independent body.

Ian Hutchinson, professor of nuclear science at the Massachusetts Institute of Technology (MIT), it is not surprising to find highly radioactive water at the site since the reactors at the plant is watered thoroughly, since the earthquake and tsunami March 11, pending the restart of the cooling system.

"I'm not particularly worried," he said on CNN. "The difference between the pressure inside the reactor and that in the containment suggests that the reactor vessel is still intact," noted Dave Lochbaum, another specialist in the Union of Concerned Scientists. "The source of this radioactivity is not clear since normally the building housing the turbine is isolated from both the reactor core and the pool containing spent nuclear fuel," he added however.

"There is no evidence that radioactivity could come from the reactor core or spent fuel damage found in the pool at the reactor," he said. "We're not sure so far with the only data" provided by the Japanese authorities. Thus, the Japanese government has measured levels of radioactive iodine 1 250 times the legal limit in the sea off Fukushima, reinforcing fears of breaking the seal of one or more reactors.

Tuesday, tighter controls on fish and seafood caught along the coast had been introduced. "If you drink 50 ounces of water everyday with this concentration of iodine of a sudden you reach the annual limit that you can absorb. It is a relatively high level," said a spokesman for the Agency security.

The Japanese authorities state, however, that the radioactivity released into the ocean could be diluted with the tides and the amount of iodine absorbed by algae and marine animals could be less. There remains the fear of diffusion of cesium 137, a radioactive substance whose concentration can not be reduced by half every 30 years.

TEPCO said he measured a concentration almost 80 times the legal limit of that substance. The environmental organization Greenpeace said it would take measurements of radioactivity outside the exclusion zone of 20 km around the plant, saying that "the authorities have always given the impression of underestimating the both the risks and extent of radioactive contamination.

" See "The answers to your questions about the terms of the Nuclear See our graphics on the scenario of catastropheSuivre special bulletins of the Japanese channel NHK, with simultaneous translation into English

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