Sunday, March 13, 2011

Nuclear Cloud, Acid Rain, Nuclear Fall Out, What To Do In Case?

Japanese Scramble to Avert Meltdowns as Nuclear Crisis Deepens After Quake

Kim Kyung-Hoon/Reuters
Officials checked for signs of radiation on children from the evacuation area near the Fukushima Daini nuclear plant in Koriyama.

TOKYO — Japanese officials struggled on Sunday to contain a widening nuclear crisis in the aftermath of a devastating earthquake and tsunami, saying they presumed that partial meltdowns had occurred at two crippled reactors and that they were facing serious cooling problems at three more.
Source: International Nuclear Safety Center
An explosion occurred at the Daiichi nuclear power plant in northern Japan after the earthquake.
The emergency appeared to be the worst involving a nuclear plant since the Chernobyl disaster 25 years ago. The developments at two separate nuclear plants prompted the evacuation of more than 200,000 people. Japanese officials said they had also ordered up the largest mobilization of their Self-Defense Forces since World War II to assist in the relief effort.
On Saturday, Japanese officials took the extraordinary step of flooding the crippled No. 1 reactor at Fukushima Daiichi Nuclear Power Station, 170 miles north of Tokyo, with seawater in a last-ditch effort to avoid a nuclear meltdown.
Then on Sunday, cooling failed at a second reactor — No. 3 — and core melting was presumed at both, said the top government spokesman, Chief Cabinet Secretary Yukio Edano. Cooling had failed at three reactors at a nuclear complex nearby, Fukushima Daini, although he said conditions there were considered less dire for now.
With high pressure inside the reactors at Daiichi hampering efforts to pump in cooling water, plant operators had to release radioactive vapor into the atmosphere. Radiation levels outside the plant, which had retreated overnight, shot up to 1,204 microsieverts per hour, or over twice Japan’s legal limit, Mr. Edano said.
NHK, Japan’s public broadcaster, flashed instructions to evacuees: close doors and windows; place a wet towel over the nose and mouth; cover up as much as possible. At a news conference, Mr. Edano called for calm. “If measures can be taken, we will be able to ensure the safety of the reactor,” he said.
One result of the venting may have been setting off an explosion, caused by either steam or hydrogen, that tore the outer wall and roof off the building housing reactor No. 1, although the steel containment of the reactor remained in place, officials said.
Even before the statement on Sunday by Mr. Edano, it was clear form radioactive materials turning up in trace amounts outside the reactors that fuel damage had occurred. The existence or extent of melting might not be clear until workers can open up the reactors and examine the fuel, which could be months.
A meltdown occurs when there is insufficient cooling of the reactor core, and it is the most dangerous kind of a nuclear power accident because of the risk of radiation releases. The radiation levels reported so far by the Japanese authorities are far above normal but still too small to pose a hazard to human health if the exposure continued for a brief period. The fear was that more core damage would bring bigger releases.
The Japanese Nuclear and Industrial Safety Agency said that as many as 160 people may have been exposed to radiation around the plant, and Japanese news media said that three workers at the facility were suffering from full-on radiation sickness.
Even before the explosion on Saturday, officials said they had detected radioactive cesium, which is created when uranium fuel is split, an indication that some of the nuclear fuel in the reactor was already damaged.
How much damage the fuel suffered remained uncertain, though safety officials insisted repeatedly through the day that radiation leaks outside the plant remained small and did not pose a major health risk.
However, they also told the International Atomic Energy Agency that they were making preparations to distribute iodine, which helps protect the thyroid gland from radiation exposure, to people living near Daiichi and Daini.

California 'closely monitoring' Japan nuclear leak

California 'closely monitoring' Japan nuclear leakAFP/JIJI PRESS – An aerial view shows the quake-damaged Fukushima nuclear power plant in the Japanese town of Futaba, …
LOS ANGELES (AFP) – California is closely monitoring efforts to contain leaks from a quake-damaged Japanese nuclear plant, a spokesman said Saturday, as experts said radiation could be blown out across the Pacific.
While officials downplayed any immediate danger, the US Nuclear Regulatory Commission deployed two experts to Japan, where the Fukushima plant, which was rocked by a large explosion earlier in the day in the aftermath of Japan's strongest-ever earthquake.
"At present there is no danger to California. However we are monitoring the situation closely in conjunction with our federal partners," Michael Sicilia, spokesman for California Department of Public Health, told AFP.
"California does have radioactivity monitoring systems in place for air, water and the food supply and can enhance that monitoring if a danger exists," he added.
He was speaking as Japanese authorities moved to calm fears of a meltdown and said a huge explosion Saturday had not ruptured the container surrounding the reactor, although there had already been some radiation leakage prior to the explosion.
Experts have suggested that, if there were a reactor meltdown or major leak at Fukushima, the radioactive cloud would likely be blown out east across the Pacific, towards the US West Coast.
"The wind direction for the time being seems to point the (nuclear) pollution towards the Pacific," said Andre-Claude Lacoste of the French Nuclear Safety Authority, briefing journalists in Paris on the Japanese crisis.
The Nuclear Regulatory Commission meanwhile said it has sent two experts to Japan, and has been in regular contact with Japanese officials about the crisis.
"We have some of the most expert people in this field in the world working for the NRC and we stand ready to assist in any way possible," commission chairman Gregory Jaczko said in a statement announcing the deployment.
He said the pair were experts in boiling water nuclear reactors and are part of a broader US aid team sent to the disaster zone.

There are rumors circulating via text messages that “acid rain” may fall on the Philippines due to Japan’s quake-hit nuclear power plant (Fukushima Daiichi nuclear plant). However, PAGASA denied the said rumors saying that there’s no basis for such claims.
According to PAGASA forecaster Aldczar Aurelio, the winds from Japan are moving away from us (Philippines). It’s not true that these winds contain acid rain.
Also, according to DOST secretary Mario Montejo, the “Chernobyl scenario’ of radioactive clouds from Fukushima Daiichi nuclear plant may be gone in few days’ time. There’s nothing to worry about because Philippines’ nuclear scientists are monitoring the situation along with the Philippine Nuclear Research Institure (PNRI).  Montejo also added that nuclear power plants have redundant safety precautions in place which include containment vessels that would keep radiation from getting out of the plant.

Read more: Effect of Nuclear Reaction/Radioactive Clouds from Japan to Philippines

Military Crew Said to Be Exposed to Radiation, but Officials Call Risk in U.S. Slight

The Pentagon was expected to announce that the aircraft carrierRonald Reagan, which is sailing in the Pacific, passed through a radioactive cloud from stricken nuclear reactors in Japan, causing crew members on deck to receive a month’s worth of radiation in about an hour, government officials said Sunday.
The officials added that American helicopters flying missions about 60 miles north of the damaged reactors became coated with particulate radiation that had to be washed off.
There was no indication that any of the military personnel had experienced ill effects from the exposure. (Everyone is exposed to a small amount of natural background radiation.)
But the episodes showed that the prevailing winds were picking up radioactive material from crippled reactors in northeastern Japan. Ever since an earthquake struck Japan on Friday, the authorities worldwide have been laying plans to map where radioactive plumes might blow and determine what, if any, danger they could pose to people.
Blogs were churning with alarm. But officials insisted that unless the quake-damaged nuclear plants deteriorated into full meltdown, any radiation that reached the United States would be too weak to do any harm.
Washington had “hypothetical plots” for worst-case plume dispersal within hours of the start of the crisis, a senior official said Sunday. The aim, the official added, was “more to help Japan” than the United States, since few experts foresaw high levels of radiation reaching the West Coast.
For now, the prevailing winds over Japan were blowing eastward across the Pacific. If they continue to do so, international stations for radioactive tracking at Wake or Midway Islands might detect radiation later this week, said Annika Thunborg, a spokeswoman for an arm of the United Nations in Vienna that monitors the planet for spikes in radioactivity.
“At this point, we have not picked up anything” in detectors midway between Japan and Hawaii, Ms. Thunborg said in an interview on Sunday. “We’re talking a couple of days — nothing before Tuesday — in terms of picking something up.”
Agencies involved in the tracking efforts include the World Meteorological Organization, the International Atomic Energy Agency and the Comprehensive Test Ban Treaty Organization, which runs a global network of more than 60 stations that sniff the air for radiation spikes.
In the United States, the Departments of Defense and Energy maintain large facilities and cadres of specialists for tracking airborne releases of radiation, both civilian and military.
On Sunday, the Nuclear Regulatory Commission said it expected no “harmful levels of radioactivity” to move on the winds to Hawaii, Alaska or the West Coast from the reactors in Japan, “given the thousands of miles between the two countries.”

Nuclear contamination: The options

Nuclear contamination: The optionsAFP/JIJI PRESS – Elderly people, evacuated from the area near the Fukushima nuclear plant, read a newspaper, with reports …
PARIS (AFP) – Evacuation, temporary shelter and iodine pills are the chief weapons for protecting civilians against nuclear fallout, experts say.
A blast on Saturday that wrecked the concrete shell surrounding the No. 1 reactor at Japan's Fukushima nuclear plant released radioactive vapour but not at levels dangerous for human health, according to Japanese officials.
Specialists say the authorities have a several-pronged strategy for shielding civilians if there is an explosive breach of the reactor, as in the April 26 1986 Chernobyl disaster.
In that event, a cloud of radioactive dust spread over parts of Ukraine and Belarus, triggering a surge in cancer and birth defects. The death toll ranges from a UN 2005 estimate of 4,000 to tens or even hundreds of thousands, proposed by non-governmental groups.
"There are three weapons against contamination -- evacuation, confinement and iodine," said Patrick Gourmelon, director of radioprotection at a French nuclear watchdog, the Institute for Radioprotection and Nuclear Safety (IRSN).
About 200,000 people have already been evacuated from residential areas around Fukushima, located 250 kilometres (120 miles) north of Tokyo.
Confinement is a highly effective tool pending evacuation to a safer area.
It consists of taking shelter in an enclosed space, preferably a basement room, whose doors and windows are then sealed tight with plastic sheets and adhesive tape.
"The point is to prevent radioactive dust from entering the lungs and the digestive tract," said Gourmelon.
"You take a good shower to remove any contact between the fallout and the skin, but you shouldn't scrub, because this helps particles to penetrate," he said. Nail-biting, smoking and sucking or licking one's fingers are also out.
In a nuclear alert, the authorities also hand out iodine pills to prevent cancers of the thyroid, which is a particular risk for babies, young children, teenagers and expectant or breast-feeding mothers.
The goal is to saturate the thyroid with "healthy iodine," shielding it from radioactive iodine, said Gourmelon.
Timing, though, is essential. Preferably, the iodine is taken an hour before a known fallout incident. Japanese guidelines say the pills should be distributed when the likely absorbed dose of radioactivity is 100 milligray, a unit named after a British physicist.

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