শনিবার, ২৪ ডিসেম্বর, ২০১১

Skeptics cast doubt on Fukushima status, even as Japan declares nuclear reactors 'stable'

Japan's government declared that the damaged reactors from the Fukushima disaster were 'stable.' Not everyone is convinced.

The Japanese government announced that the Fukushima nuclear complex, heavily damaged by the March 11 tsunami in the world's worst nuclear disaster since Chernobyl, is now stable.? But serious doubts remain about Fukushima's status, as officials remain unable to confirm the status of the reactors' fuel and an undercover report impugns the clean-up efforts' efficacy.

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Prime Minister Yoshihiko Noda told a government nuclear emergency meeting that "The reactors have reached a state of cold shutdown" and are "stable," reports Reuters.? Mr. Noda and his environment and nuclear crisis minister, Goshi Hosono, both said that the situation at the plant is under control, though the clean-up may still take decades.? The Tokyo Electric Power Co. (TEPCO), which operates the reactor and has been leading the clean-up, had been attempting to achieve cold shutdown before the end of the year.

The state of "cold shutdown" means that the water used to cool the nuclear fuel rods in the reactors is at a temperature below boiling, thereby preventing the fuel rods from overheating and emitting excessive radiation. The Japan Times reports that government officials said that the temperatures of the lower portions of the rods' containment vessels measure 38.9 degrees C in reactor 1, 67.5 degrees in reactor 2, and 57.4 degrees in reactor 3.? "If the authorities are correct and cooling of the reactors is stable, it would be an important milestone in ending the world's worst nuclear accident since the 1986 Chernobyl crisis," writes the Times.

But the Times adds that skeptics worry that the readings would be inaccurate if the melted fuel rods punctured their containment vessels and fell to the bottoms of the outer containment tanks.? TEPCO has not been able to take direct measurements of the temperatures at the bottoms of the containment vessels, and the site is still too radioactive for the fuel rods' status to be visually confirmed.

Even if the reactor is under control, the cleanup could still take 30 years, and the problems remain "immense," writes The Wall Street Journal.

Indeed, there can be few firm declarations about the plant's status. Daiichi's reactors are littered with debris. Many measurement and control systems are on the blink. Radiation levels are too high for people to get close to the reactors, leaving engineers and scientists to make important judgments using computer simulations, scattered bits of data and guesses.

And whether the cleanup effort is moving ahead is dubious, according to an undercover report by freelance reporter Tomohiko Suzuki. Mr. Suzuki worked at the Fukushima No. 1 site for a month as a general laborer while documenting a long list of substandard practices and unsafe behavior by companies involved in cleanup at the plant. He charges that "absolutely no progress is being made" toward resolving the Fukushima crisis, reports the Mainichi Daily News.

Source: http://rss.csmonitor.com/~r/csmonitor/globalnews/~3/OU-e5RzwBpg/Skeptics-cast-doubt-on-Fukushima-status-even-as-Japan-declares-nuclear-reactors-stable

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