Japan says stricken nuclear power plant in cold shutdown
A cold shutdown occurs when water used to cool nuclear fuel rods remains below the boiling point, preventing the fuel from reheating.
Fri, Dec 16, 2011 at 03:09 AM
NUCLEAR DISASTER: The Fukushima Daiichi plant was wrecked on March 11 by a huge earthquake and a towering tsunami that knocked out its cooling systems, triggering meltdowns, radiation leaks and mass evacuations. (Photo: ZUMA Press)
TOKYO - Japan declared its tsunami-stricken Fukushima nuclear power plant to be in cold shutdown on Friday in a major step toward resolving the world's worst nuclear crisis in 25 years.
The Fukushima Daiichi plant, 150 miles northeast of Tokyo, was wrecked on March 11, 2011, by a huge earthquake and a towering tsunami which knocked out its cooling systems, triggering meltdowns, radiation leaks and mass evacuations.
In making the much-anticipated announcement, Prime Minister Yoshihiko Noda sought to draw a line under the crisis phase of the emergency at the plant, though experts say it could be 40 years before the site is finally cleaned up.
"The reactors have reached a state of cold shutdown," he told a government nuclear emergency response meeting.
"A stable condition has been achieved. It is judged that the accident at the plant itself has ceased," he added, noting radiation levels at the boundary of the plant could now be kept at low levels, even in the event of "unforeseeable incidents."
A cold shutdown is when water used to cool nuclear fuel rods remains below boiling point, preventing the fuel from reheating. One of the chief aims of the plant's operator, Tokyo Electric Power, had been to bring the reactors to cold shutdown by the year-end.
After months of efforts, the water temperature in all three of the affected reactors fell below boiling point by September, but Tepco has been cautious about declaring a cold shutdown, saying it had to see if temperatures and the amount of radiation emitted from the plant remained stable.
The declaration of a cold shutdown could have repercussions well beyond the plant: it is a government pre-condition before it allows about 80,000 residents evacuated from within a 12 mile radius of the plant to return home.
But Kazuhiko Kudo, professor of nuclear engineering at Kyushu University, said authorities still needed to determine exactly the status of melted fuel inside the reactors and stabilize a makeshift cooling system, which handles the tens of thousands of tons of contaminated water accumulated on-site.
"What is more important is the next steps the government and Tepco decide to take," Kudo said.
Huge costs, anxiety
The government and Tepco will aim to begin removing the undamaged nuclear rods from Daiichi's spent fuel pools next year. However, retrieval of fuel that melted down in their reactors may not begin for another decade.
The enormous cost of the cleanup and compensating the victims of the disaster has drained Tepco financially. The government may inject about $13 billion into the company as early as next summer in a de facto nationalization, sources told Reuters last week.
An official advisory panel estimates Tepco may have to pay about $57 billion in compensation in the first two years after the nuclear crisis, and that it will cost 1.15 trillion yen to decommission the plant although experts say the figure could be as high as $51 billion.
Japan also faces a massive cleanup task outside the plant if residents are to be allowed to go home. The Environment Ministry says about 930 square miles of land around the plant may need to be decontaminated, an area roughly the size of Luxembourg.
The crisis shook the public's faith in nuclear energy and Japan is now reviewing an earlier plan to raise the proportion of electricity generated from nuclear power to 50 percent by 2030 from 30 percent in 2010.
Japan may not immediately walk away from nuclear power, but few doubt that nuclear power will play a lesser role in future.
Living in fear of radiation is part of life for residents both near and far from the plant. Cases of excessive radiation in vegetables, tea, milk, seafood and water have stoked anxiety despite assurances from public officials that the levels detected are not dangerous.
Chernobyl's experience shows that anxiety is likely to persist for years, with residents living near the former Soviet plant still regularly checking produce for radiation before consuming it 25 years after the disaster.
(Editing by Tomasz Janowski, Mark Bendeich and Robert Birsel)
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