Quote:Thousands ordered to evacuate as nuclear emergency is declared

SONIA VERMA

Globe and Mail Update

Published Friday, Mar. 11, 2011 7:27AM EST

Last updated Friday, Mar. 11, 2011 10:11PM EST



Japan declared a nuclear emergency after Friday's earthquake compromised the cooling systems of at least two of its nuclear plants, forcing the evacuation of people living near both of them. Officials warned that small amounts of radioactive material were likely to leak from the plants, known as Daiichi and Daini and operated by Tokyo Electric Power.

The evacuation zone for the Daiichi plant was tripled to 10 kilometres after authorities detected eight times the normal radiation levels outside the facility. Inside the plant's control room, levels were a thousand times higher than normal. The evacuation of the second Daini plant was for a 1.6-kilometre radius because "there is no sign that radiation has been emitted outside," an official said.
As workers struggled to cool two of the plant's reactors, the cooling systems of three reactors at a second plant failed, fuelling fears of more widespread problems.
By Saturday morning Japan had declared states of emergency for five reactors at the two plants. The news capped a day fraught with confusion over the risk posed by possible radioactive leakage from Japan's 11 nuclear reactors, all of which automatically shut down during the earthquake.
While the shutdowns were successful, some of the reactors did not appear to be cooling properly, due to disruptions to the electrical supply that powers the cooling pumps. There were worries that a backup battery-operated system would not be robust enough to bring down the reactor's temperatures.
The Daiichi and Daini plants are 15 kilometres apart in Fukushima Prefecture, about 240 kilometres north of Tokyo and close to the quake's epicenter off the coast.
Meanwhile, the Japanese government seemed caught between competing impulses, wanting to ease public fear on the one hand, while taking measures against the risk of radioactive contamination on the other.
In a statement broadcast on the Japanese state television network NHK, nuclear safety officials said there was "no immediate health hazard" to the public from the leakage, which was characterized as "minute." Nuclear experts appeared on camera, using diagrams to explain how the elevated levels of radiation were caused by a breach in the containment building, not the reactor itself.
But as coolant pressure rose to one and a half times normal inside one of the plant's six reactors, the government announced it would release radioactive steam into the atmosphere, a measure meant to ease the pressure inside the reactor that it said would pose no significant threat to public safety.
Tokyo Electric said that by Saturday morning it had installed a mobile generator at Daiichi to ensure that the cooling system would continue operating even after reserve battery power was depleted. Even so, the company said it was considering a "controlled containment venting" in order to avoid an "uncontrolled rupture and damage" to the containment unit.
"With evacuation in place and the oceanbound wind, we can ensure the safety," a nuclear safety official, Yukio Edano, said at a news conference early Saturday.
While most experts continued to play down the risk of a Chernobyl-style meltdown, the scramble to contain the risk posed by the compromised reactor underscored some of the dangers associated with the nuclear power on which Japan relies to produce one-third of its electricity.
Japan's reactors are designed to hold up under the harsh punishment of an earthquake, but some analysts had expressed concern over the enforcement of safety standards at the facilities. The failure of the Fukushima plants' diesel generators, which ran for only a short time after starting up when the main power supply failed, leading to a crippling loss of cooling capacity, raised particular concern.
"Obviously everybody wants to know why the diesel generator stopped working. Because you don't just seismically qualify the reactor, you have to seismically qualify everything. This whole thing will become a huge case study," said Ian Wilson, president of the Canadian Nuclear Society.
The problems in each of the faulty reactor's cases appeared to stem from the cooling systems, which become especially crucial in the event of an automatic shutdown such as that triggered by the earthquake. Even after the nuclear fission process is stopped, the cooling system must continue to work to keep the reactor from melting down. Pumps operated by electricity, supplied through the national grid or by backup diesel generators, circulate water through the system. If they fail, the pumps operate on batteries, which eventually run out.
"You can't just say tools down and shut everything off. You get what you call heat decay," said William Garland, a professor in the department of engineering physics at McMaster University.
"So even when you shut off, you're generating 6 per cent heat. In the case of this reactor, that could be the equivalent of 30,000 toasters. If you don't take that heat away, then you're going to overheat and something's going to melt."
Two workers were reported missing at the Daiichi plant, but the company did not explain what might have happened to them.
During much of the early morning on Saturday, safety officials focused on getting emergency power supplies to the Daiichi plant to restore the normal cooling function. The International Atomic Energy Agency stated new electrical supplies had arrived at the site to prevent the situation from becoming more dangerous.
In the meantime, most observers said they would take a wait-and-see approach: "This is still playing out," Mr. Wilson said.
"So far it looks like all of the systems are kicking in. … There's this public perception that there's this green goo that's somehow going to burst out of these reactors, but that's simply not the case."

http://www.theglobeandmail.com/news/world/asia-pacific/thousands-ordered-to-evacuate-as-nuclear-emergency-is-declared/article1938199/

Magda Hassan Wrote:Well, it's happened. Earthquake, tsunami and now the nuclear reactor has exploded. Roof and walls gone. The 2nd reactor is about to meltdown as well.
http://www.msnbc.msn.com/id/42044156/ns/world_news-asia-pacific/
TOKYO An explosion was heard and smoke was seen at a quake-hit Japanese nuclear power plant on Saturday, officials said.
Several workers were injured by the blast at Fukushima Unit 1, Japanese TV station NHK reported. A trail of white smoke was seen at the site and shaking was felt, The Associated Press reported.
Britain's Sky News cited NHK as saying that the walls and roof of a building at the site had been destroyed.
Japan earlier warned of a meltdown after the nuclear reactor was damaged when a massive earthquake and tsunami struck the northeast coast.
Experts said any threat of widespread radiation leaks would be contained as long as the reactor's outer container is intact.
Authorities have been scrambling to reduce pressure at two nuclear power plants in Fukushima, 150 miles north of Tokyo, damaged by Friday's devastating quake .
Two reactors had lost cooling ability at the Fukushima Daiichi nuclear power plant. Because of the overheating, a meltdown was possible at one of the reactors, said Ryohei Shiomi, an official with Japan's nuclear safety commission.
But even if there was a meltdown, it wouldn't affect people outside a six-mile radius, he said. Most of the 51,000 residents living within the danger area had been evacuated, he said.
Before the blast, authorities detected eight times the normal radiation levels outside the facility and 1,000 times normal inside Unit 1's control room.

Magda Hassan Wrote:Dr Helen Caldicott
NHK: "The government's Nuclear and Industrial Safety Agency says nuclear material cesium has been detected near the Number One reactor at the Fukushima Number One nuclear power plant. The agency says the detection indicates that some of the nuclear fuel at the reactor may have started melting, because cesium is produced during a nuclear chain reaction." Very bad news.