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World Partial Meltdown 'highly Possible' At Japan N-plant

spnadmin

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Japanese officials were struggling on Sunday with a growing nuclear crisis and the threat of multiple meltdowns, as more than 170,000 people were evacuated from the quake- and tsunami-savaged northeastern coast where police fear more than 10,000 people may have already died.

A partial meltdown was already likely under way at one nuclear reactor, a top official said, and operators were frantically trying to keep temperatures down at the power plant’s other units and prevent the disaster from growing even worse.

Chief Cabinet Secretary Yukio Edano said on Sunday that a hydrogen explosion could occur at Unit 3 of the Fukushima Dai-ichi nuclear complex, the reactor that could be melting down. That would follow a blast the day before in the power plant’s Unit 1, as operators attempted to prevent a meltdown by injecting sea water into it.

“At the risk of raising further public concern, we cannot rule out the possibility of an explosion,” Mr. Edano said. “If there is an explosion, however, there would be no significant impact on human health.”

More than 170,000 people had been evacuated as a precaution, though Mr. Edano said the radioactivity released into the environment so far was so small it didn’t pose any health threats.

A complete meltdown — the collapse of a power plant’s systems and its ability to keep temperatures under control — could release uranium and dangerous contaminants into the environment and pose major, widespread health risks.

Up to 160 people, including 60 elderly patients and medial staff who had been waiting for evacuation in the nearby town of Futabe, and 100 others evacuating by bus, might have been exposed to radiation, said Ryo Miyake, a spokesman from Japan’s nuclear agency. The severity of their exposure, or if it had reached dangerous levels, was not clear. They were being taken to hospitals.

Mr. Edano told reporters that a partial meltdown in Unit 3 of the Fukushima Dai-ichi power plant was “highly possible.”

Asked whether a partial meltdown had occurred, Mr. Edano said that “because it’s inside the reactor, we cannot directly check it but we are taking measures on the assumption” that it had.

Japan struggled with the nuclear crisis as it tried to determine the scale of the Friday disasters, when an 8.9-magnitude earthquake, the most powerful in the country’s recorded history, was followed by a tsunami that savaged its northeastern coast with breathtaking speed and power.

At least 1,000 people were killed — including some 200 bodies discovered on Sunday along the coast — and 678 were missing, according to officials, but police in one of the worst-hit areas estimated the toll there alone could eventually top 10,000.

The scale of the multiple disasters appeared to be outpacing the efforts of Japanese authorities to bring the situation under control more than two days after the initial quake.

Rescue teams were struggling to search hundreds of kilometers of devastated coastline, and thousands of hungry survivors huddled in darkened emergency centers cut off from rescuers and aid. At least a million households had gone without water since the quake, and food and gasoline were quickly running out across the region. Large areas of the countryside were surrounded by water and unreachable. Some 2.5 million households were without electricity.

Japanese Trade Minister Banri Kaeda warned that the region was likely to face further blackouts, and power would be rationed to ensure supplies to essential facilities.

The government doubled the number of troops pressed into rescue and recovery operations to about 100,000 from 51,000, as powerful aftershocks continued to rock the country. Hundreds have hit since the initial temblor.

Unit 3 at the Fukushima plant is one of the three reactors that had automatically shut down and lost cooling functions necessary to keep fuel rods working properly due to power outage from the quake. The facility’s Unit 1 is also in trouble, but Unit 2 has been less affected.

On Saturday, an explosion destroyed the walls of Unit 1 as operators desperately tried to prevent it from overheating and melting down.

Without power, and with its pipes and pumps destroyed, authorities resorted to drawing seawater mixed with boron in an attempt to cool the unit’s overheated uranium fuel rods. Boron disrupts nuclear chain reactions.

The move likely renders the 40-year-old reactor unusable, said a foreign ministry official briefing reporters. Officials said the seawater will remain inside the unit, possibly for several months.

Robert Alvarez, senior scholar at the Institute for Policy Studies and former senior policy adviser to the U.S. secretary of energy, told reporters that the seawater was a desperate measure.

“It’s a Hail Mary pass,” he said.

He said that the success of using seawater and boron to cool the reactor will depend on the volume and rate of their distribution. He said the dousing would need to continue nonstop for days.

Another key, he said, was the restoration of electrical power, so that normal cooling systems can operate.

Mr. Edano said the cooling operation at Unit 1 was going smoothly after the sea water was pumped in.

Operators released slightly radioactive air from Unit 3 on Sunday, while injecting water into it hoping to reduce pressure and temperature to prevent a possible meltdown, Edano said.

He said radiation levels just outside the plant briefly rose above legal limits, but since had declined significantly. Also, fuel rods were exposed briefly, he said, indicating that coolant water didn’t cover the rods for some time. That would have contributed further to raising the temperature in the reactor vessel.

At an evacuation center in Koriyama, about 60 km from the troubled reactors and 190 km north of Tokyo, medical experts had checked about 1,500 people for radiation exposure in an emergency testing center, an official said.

On Sunday, a few dozen people waited to be checked in a collection of blue tents set up in a parking lot outside a local gymnasium. Fire engines surrounded the scene, with their lights flashing.

Many of the gym’s windows were shattered by the quake, and glass shards littered the ground.

“The situation there is very bad,” said Takehito Akimoto, a 39-year-old high school teacher. “We are still trying to confirm the safety of our children, many of them scattered with their families or friends, so we don’t know where they are or if they are OK.”

A steady flow of people — the elderly, schoolchildren and families with babies — arrived at the center, where they were checked by officials wearing helmets, surgical masks and goggles.

Officials placed Dai-ichi Unit 1, and four other reactors, under states of emergency Friday after operators lost the ability to cool the reactors using usual procedures.

An additional reactor was added to the list early Sunday, for a total of six — three at the Dai-ichi complex and three at another nearby complex. Local evacuations have been ordered at each location. Japan has a total of 55 reactors spread across 17 complexes nationwide.

Officials began venting radioactive steam at Fukushima Dai-ichi’s Unit 1 to relieve pressure inside the reactor vessel, which houses the overheated uranium fuel.

Concerns escalated dramatically on Saturday when that unit’s containment building exploded.

Officials were aware that the steam contained hydrogen and were risking an explosion by venting it, acknowledged Shinji Kinjo, spokesman for the government’s Nuclear and Industrial Safety Agency, but chose to do so because they needed to keep circulating cool water on the fuel rods to prevent a meltdown.

To cool the reactor fuel, operators needed to keep circulating more and more cool water on the fuel rods. But the temperature in the reactor vessel apparently kept rising, heating the zirconium cladding that makes up the fuel rod casings.

If the temperature inside the Fukushima reactor vessel rose further, to roughly 4,000°F (2,200°C), then the uranium fuel pellets would start to melt. But once the zirconium reached 2,200°F (1,200°C), it reacted with the water, becoming zirconium oxide and hydrogen.

When the hydrogen-filled steam was vented from the reactor vessel, the hydrogen reacted with oxygen, either in the air or water outside the vessel, and exploded.

A similar “hydrogen bubble” problem concerned officials at the 1979 Three Mile Island nuclear disaster in Pennsylvania, until it dissipated.

According to experts interviewed by The Associated Press, any melted fuel would eat through the bottom of the reactor vessel. Next, it would eat through the floor of the already-damaged containment building. At that point, the uranium and dangerous byproducts would start escaping into the environment.

At some point in the process, the walls of the reactor vessel — 15 cm of stainless steel — would melt into a lava-like pile, slump into any remaining water on the floor, and potentially cause an explosion much bigger than the one caused by the hydrogen. Such an explosion would enhance the spread of radioactive contaminants.

If the reactor core became exposed to the external environment, officials would likely began pouring cement and sand over the entire facility, as was done at the 1986 Chernobyl nuclear accident in the Ukraine, Peter Bradford, a former commissioner of the U.S. Nuclear Regulatory Commission, said in a briefing for reporters.

At that point, Mr. Bradford added, “many first responders would die.

http://www.thehindu.com/news/international/article1534185.ece?homepage=true
 

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spnadmin

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Upadate to this story at

Japan Earthquake: State Of Emergency Declared At Onagawa Nuclear Power Plant

KORIYAMA, Japan (AP) — The U.N. nuclear agency says Japan has declared a state of emergency at another earthquake-affected nuclear plant where higher-than-permitted levels of radioactivity were measured.

The International Atomic Energy Agency says Japan informed it that the source of the radioactivity at the Onagawa power plant is being investigated. It said all three reactors at the plant are under control.

http://www.huffingtonpost.com/2011/...uclear-plant-state-of-emergency_n_835059.html
 

spnadmin

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Further developments

Anxiety in Japan grows as rescue workers find more bodies

Sendai, Japan (CNN) -- Rescue workers scoured tangled and displaced piles of debris Tuesday, searching for survivors, as crews struggled to keep control at a damaged nuclear plant on the fifth day of the developing disaster in Japan.

Friday's 9.0-magnitude earthquake and the ensuing tsunami killed thousands, based on official and Japanese media reports, but an exact accounting of the disaster remains hidden beneath widespread damage that rescuers are only beginning to unearth.

The confirmed death toll, growing every few hours, reached 2,414 on Tuesday. But that didn't account for the thousands of bodies Japan's Kyodo News Agency said had been found in the Miyagi Prefecture on Japan's northeast coast. The number of dead is expected to rise as rescuers reach more hard-hit areas.

At least 3,118 people were still missing Tuesday, the National Police Agency said. Public broadcaster NHK reported that 450,000 people were living in shelters.

At the same time, officials are fighting to contain a nuclear emergency. The earthquake and tsunami led to problems at three of the country's nuclear power plants.

An "explosive impact" occurred Tuesday morning at the No. 2 reactor at the Fukushima Daiichi nuclear power plant in northeastern Japan, a day after a hydrogen explosion rocked another reactor, the plant's owner said. Pressure readings indicated some damage to the No. 2 reactor's suppression pool, a donut-shaped reservoir at the base of the reactor containment vessel.

An explosion in a building housing the No. 3 reactor at the Fukushima Daiichi plant injured 11 workers Monday. A similar explosion over the weekend occurred in the No. 1 reactor.

Yukio Edano, Japan's chief Cabinet secretary, said he could not rule out the possibility of a meltdown at all three troubled reactors. While sea water was being pumped into the reactors in an effort to prevent further damage, "It cannot necessarily be called a stable situation," Edano said early Tuesday.

In Tokyo, where many trains were not running or were severely delayed because of power outages, residents worried about the threat of more aftershocks as they started their workweek Monday.

"It didn't really feel safe going to an empty office," said Tokyo resident Mia Moore, citing the ongoing tremors that continue to rattle the city every few hours. "People want to stay with their families at this time to recover, really. It's quite exhausting feeling so nervous all the time. I think people want to get back to normality as soon as they can."

But normalcy seems a distant memory across the hardest-hit region of Japan. NHK, citing police and disaster management officials, reported that 63,000 buildings had been damaged, more than 6,000 of them obliterated.

In Miyagi Prefecture, rescue workers sifted through mountains of debris, and hope for survivors appeared to dim.

In the Sendai area, where buildings were disintegrated by rushing water within seconds during the tsunami, a bizarre mix of sport-utility vehicles, cabinets, sofas, a taxi and a doll were heaped in a pile outside the remnants of a house.

Solemn residents waited in lines that stretched blocks for food, water and gas. Despite the devastation surrounding them, the crowds appeared calm and orderly, even as stores rationed what they would sell to individual people.

At a shelter in Sendai, a shell-shocked man who fled the tsunami would not let go of his 3-week-old infant. "I have to protect my children. I have to protect my children," he said.

Another survivor wiped away tears after someone she barely knew gave her food and water.

Cold weather has increased the hardship for disaster victims and rescuers. Rescuers report that some victims have been exposed to cold weather and water, in some cases for days. Conditions are expected to worsen, with temperatures forecast to drop below freezing by Wednesday across portions of the earthquake zone, accompanied by snow, heavy rain and the threat of mudslides.

About 15,000 people have been rescued, Kyodo News reported Monday, citing Japanese Prime Minister Naoto Kan. On Sunday, he called on people to pull together and face sacrifices during what he called the "toughest and most difficult crisis for Japan" since the end of World War II.

Among the residents rescued was a woman carried into a shelter by a civil defense solider, NHK reported. After he gingerly set her down, the woman rose to her feet with some difficulty and bowed to the soldier, told him she was all right, bowed again and then collected herself to briefly tell her story, paraphrased by an NHK interpreter:

"She had been waiting for help all night, outside. She had been washed away by the wave. ... The moment she opened the door of the house, the water flooded in. ... She grabbed hold of a tree and hung on, hung on for dear life with the water all around her. A ... floor mat floated by, and she grabbed it and held on to that."

As the woman spoke in Japanese, the interpreter's voice trembled in English: "Her daughter was washed away. She was washed away, and she has not found her."

The problem of trying to keep Japan's large, modern industrial economy running added to the difficulties facing the nation.

With the imperiled Fukushima plant offline, Tokyo Electric Power said it was expecting a shortfall of about 25 percent capacity, which necessitated blackouts. Up to 45 million people will be affected by the rolling outages, which will last until April 8.

Experts predict that the earthquake and tsunami will rank among the costliest natural disasters on record.

Japan's central bank announced plans Monday to inject 15 trillion yen ($186 billion) into the economy to reassure global investors of the stability of Japanese financial markets and banks.

Still, Japanese markets dropped sharply Tuesday for a second day, falling nearly 6% in the first hour of trading. The Nikkei-225 index, the most prominent measure of Tokyo market stocks, dropped 566 points, or 5.9%, within the first 60 minutes of the session.

That was on top of a 6.2% drop Monday, the first full trading day after the quake, which also marked the largest single-day fall since September 2008 after the collapse of Lehman Brothers during the financial crisis.

A massive emergency response operation is under way in northern Japan, with world governments and international aid groups coming together to bring relief to the beleaguered island nation. Ninety-one countries and regions and six international organizations have offered assistance, according to the Japanese Foreign Affairs Ministry.

Friday's quake was the strongest in recorded history to hit Japan, according to U.S. Geological Survey records that date to 1900. The USGS revised the magnitude of the quake upward to 9.0 on Monday, from 8.9. The world's largest recorded quake took place in Chile on May 22, 1960, with a magnitude of 9.5, the agency said.

http://www.cnn.com/2011/WORLD/asiapcf/03/14/japan.disaster/index.html?hpt=T1
 

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Radiation fears after Japan blast



Radiation from Japan's quake-stricken Fukushima Daiichi nuclear plant has reached harmful levels, the government says.

The warning comes after the plant was rocked by a third blast, which appears to have damaged one of the reactors' containment systems for the first time.

If it is breached, there are fears of more serious radioactive leaks.

Officials have extended the danger zone, warning residents within 30km (18 miles) to evacuate or stay indoors.

Analysis


It appears that for the first time, the containment system around one of the Fukushima Daiichi reactors has been breached.

Officials have referred to a possible crack in the suppression chamber of reactor 2 - a large doughnut-shaped structure below the reactor housing. That would allow steam, containing radioactive substances, to escape continuously.

This is the most likely source of the high radioactivity readings seen near the site. Another possible source is the fire in reactor 4 building - believed to have started when a pool storing old fuel rods dried up.

The readings at the site rose beyond safe limits - 400 millisieverts per hour (mSv/hr), when the average person's exposure is 3mSv in a year.

A key question is whether this is just a transient spike, which might be expected if number 2 is the source, or whether the high levels are sustained.

In the meantime, the key task for workers at the plant remains to get enough water into the reactors - and, now, into the spent fuel pools - with the poor resources at their disposal.

The government later said that radiation levels at the plant's main gate had fallen sharply.

The crisis has been prompted by last Friday's 9.0-magnitude quake and tsunami in north-eastern Japan.

On Tuesday morning, reactor 2 became the third to explode in four days at the Fukushima Daiichi plant.

A fire also briefly broke out at reactor 4, and is believed to have caused radioactive leaks.

Reactor 4 had been shut down before the quake for maintenance, but its spent nuclear fuel rods are still stored on the site.

Chief Cabinet Secretary Yukio Edano said they were closely watching the remaining two reactors at the plant, five and six, as they had begun overheating slightly.

He said cooling seawater was being pumped into reactors one and three - which were returning to normal - and into reactor two, which remained unstable.

There was a hydrogen blast in reactor 3 on Monday, following another in reactor 1 on Saturday.

Radiation levels in the Japanese capital - 250km (155 miles) away - were reported to be higher than normal, but officials said there were no health dangers.
Flights cancelled

Tokyo residents have been stocking up on supplies, with some stores selling out of items such as food, water, face masks and candles.

"Do not go outside”

Housewife Mariko Kawase, 34, told AFP news agency: "I am shopping now because we may not be able to go out due to the radiation."

Radiation levels in Chiba prefecture, next to Tokyo, were 10 times above normal levels, Kyodo News reports.

In a televised address, Prime Minister Naoto Kan said: "There is still a very high risk of more radiation coming out."

Homes sealed

He said that 140,000 people living within between 20km (12 mile) and 30km of the plant were at risk and should not leave their homes.

Some 70,000 residents within 20km have already been evacuated, and the premier urged anyone left in that exclusion zone to leave.

"Now we are talking about levels that can impact human health," said the chief cabinet secretary.

He told residents: "Please do not go outside. Please stay indoors. Please close windows and make your homes airtight.

"Don't turn on ventilators. Please hang your laundry indoors."

Japan also announced a 30-km no-fly zone around the plant to prevent planes spreading the radiation further afield.

After Tuesday's blast, radiation dosages of up to 400 millisieverts per hour were recorded at the site.

Rolling blackouts

A single dose of 1,000 millisieverts causes temporary radiation sickness such as nausea and vomiting.

RADIATION AND CANCER

* Experts say even small radiation doses, as low as 100 millisieverts, can slightly raise cancer risk
* Exposure to 1,000 millisieverts is estimated to increase risk of fatal cancer by about 5%
* Leukaemia, a bone marrow cancer, is the most common radiation-induced cancer
* Others include cancer of lung, skin, thyroid, breast and stomach; can take years to develop
* Half of those exposed to between 4,000-5,000 millisiverts die in a month

* Q&A: Health effects of radiation
Rolling blackouts would affect five million households on Tuesday, said Tokyo Electric Power Co (Tepco), which runs the 40-year-old plant.

Japan's nuclear safety agency said earlier it suspected Tuesday's blast may have damaged reactor 2's suppression chamber.

The BBC's Chris Hogg in Tokyo says that would make it a more serious incident than the previous explosions, which were thought just to have damaged the buildings housing the reactors.

The latest official death toll from the quake and tsunami stands at about 2,400 - but some estimates suggest at least 10,000 may have been killed.

Thousands are still unaccounted for - including hundreds of tourists - while many remote towns and villages have not been reached.

More than 500,000 people have been made homeless.

The government has deployed 100,000 troops to lead the aid effort.

The UK Foreign Office has updated its travel advice to warn against all non-essential travel to Tokyo and north-eastern Japan. British nationals and friends and relatives of those in Japan can contact the Foreign Office on +44(0) 20 7008 0000.

http://www.bbc.co.uk/news/world-12740843
 

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Ambarsaria

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My soul tells me that the wrath of the "Fukushima Daiichi nuclear plant" is subsiding. It will lead to great learning and many fold benefits into the future.


  • Don't tell me how bad it is, tell me how bad it could have been so I can be thankful!

Sat Sri Akal.
 

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