December 16, 2011

Japan PM declares 'cold shutdown' at Fukushima

Engineers have brought the crippled Fukushima nuclear plant to a "cold shutdown condition", nine months after the earthquake and tsunami, Japan has confirmed.
Prime Minister Yoshihiko Noda made the announcement at a nuclear task-force meeting.
Declaring a cold shutdown condition is seen as a key milestone in efforts to bring the plant under control.
But the government says it will take decades to dismantle it completely.
The six-reactor Fukushima Daiichi nuclear plant was badly damaged by the 11 March earthquake and tsunami. Blasts occurred at four of the reactors after waves knocked out vital cooling systems.
Workers at the plant, which is operated by Tokyo Electric Power Company (Tepco), have been using sea water to cool the reactors. Waste water has built up and some contaminated liquid has been released into the sea.
A 20km (12m) exclusion zone remains in place around the plant.
Leaks ongoing
The Japanese government said earlier this year that it was aiming to reach a "cold shutdown condition" at the plant by the end of the year.


Retired teachers Yuji and Tetsuko Takahashi are among the tens of thousands of people forced to abandon their homes around the Fukushima plant. They were planning to watch the prime minister's announcement on the television. The set was donated to them by wellwishers like everything else in their government-provided Tokyo apartment - even the clothes on their backs.
"Even when we are told it has been shut down I can't believe it," says Tetsuko. "From the start the government officials have lied to us. One of the top officials said on TV that there was no meltdown, but it happened. The actual situation is much, much worse than we were told from the beginning."
The couple's main goal now is to return home, to get out of the 26th floor apartment and back to the garden they love. The exclusion zone could remain in force for years, but they are willing to brave the contamination. "We are old, 67 and 61," says Tetsuko . "So maybe the radiation would make the risk of getting cancer higher, but it would take five or 10 years. We are going to die before we get seriously ill."
This is where water that cools nuclear fuel rods remains below boiling point, meaning that the fuel cannot reheat.
Tepco has also defined it as bringing the release of radioactive materials under control and reducing public radiation exposure to a level that does not exceed 1mSv/year at the site boundary.
Attending a meeting of the nuclear disaster task force, Mr Noda said that conditions for a cold shut-down had been met.
"Even if unforeseeable incidents happen, the situation is such that radiation levels on the boundary of the plant can now be maintained at a low level," he said.
The prime minister is due to address a news conference later in the day.
With the reactors stable, the government will review evacuation zones established in the immediate aftermath of the incident, it reports.
More than 80,000 people had to leave the area, but radiation levels in some places remain too high for them to return home.
Earlier this week, the government said it could take up to 40 years to fully decommission the plant and clean up surrounding areas.
Spent fuel rods and melted fuel inside the reactors must be removed. Waste water must also be safely stored.
Contamination has been found in foodstuffs from the region including rice, beef and fish, while radioactive soil has also been found in some areas.
Some experts have also warned that the plant could be further damaged if a powerful aftershock were to strike.
Engineers are also continuing to encounter new problems - last week Tepco officials confirmed that 45 cubic metres (1,590 cubic feet) of water had leaked into the sea from a crack in the foundation of a water treatment facility.
Fukushima cold shutdown graphic

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