EUA planeiam novas restrições sobre tecnologia de chips na China

[Quimporta]

Robots Arrive at Fukushima Nuclear Site with Unclear Mission

Generally, bots have proved effective operating in high-radiation environments, but Japan's nuclear crisis poses new challenges
By Larry Greenemeier | March 24, 2011 |

(...)


TEPCo summoned a small corps of military-grade robots last week from iRobot Corp. in Bedford, Mass. Japan's Mitsui Engineering & Shipbuilding Co. last week sent its Disaster Monitoring Robot, or Moni-Robo, to the Daiichi site as well. Other robotics companies, including Canada's Inuktun Services, are also fielding inquiries about how their technology might be of use. Each of the robots of interest moves on tracks and features a mechanical hand that can be used to lift and manipulate objects.

The roles that robots might play in Japan will depend upon the emergency responders' priorities, whether this includes handling intensely hot or radioactive materials or, later removing sludge from the site or drilling core samples to determine how deeply radiation may have penetrated the facility's walls and floor, says William "Red" Whittaker, a Carnegie Mellon University robotics professor and director of the Field Robotics Center at the school's Robotics Institute in Pittsburgh. Whittaker and several Carnegie Mellon colleagues built robots in the late 1970s and early 1980s to inspect and perform repairs in the basement of Three Mile Island Nuclear Generating Station following the near meltdown there in 1979.

The robots

Mitsui's 600-kilogram Moni-Robo is reportedly on site at Daiichi. The one-armed robot is designed to be operated remotely—from as far as a kilometer away—and includes a camera that can take video as well as 3-D thermographic images. The 150-centimeter-tall Moni-Robo rolls along on tracks and also features sensors for measuring radioactivity and detecting combustible gases.

Inuktun, based in Nanaimo, British Columbia, specializes in making remote-controlled video cameras and "crawler" robots in a variety of sizes, ranging from the Versatrax 100 (which fits in a pipe 10 centimeters in diameter) to the Versatrax 450 TTC (which is 38 centimeters in diameter). These crawler bots are used primarily to inspect confined spaces such as pipes and sewers. "We have not sent any equipment to Japan specifically for the earthquake or Daiichi reactor site, but we do have a representative company in Tokyo that has some of our demonstration equipment," Inuktun president Colin Dobell says. "We believe it is being deployed, but we have not been able to confirm anything."

Four iRobot systems—two Packbots and two Warriors—reached Tokyo Monday night along with six of the company's engineers, who spent Tuesday unpacking the bots, installing batteries and running tests, says Tim Trainer, iRobot's vice president of operations. Given that the Packbot is designed primarily for explosive ordinance disposal and the Warrior is a prototype that will not be commercially available until this summer, iRobot's engineers still need to discuss the robots' capabilities, operation and limitations with TEPCo personnel, he adds.

The 68-kilogram iRobot Warriors were modified so they could carry a 6.4-centimeter fire hose should more water be needed somewhere. Each unit features an arm that can lift up to about 100 kilograms as well as an adjustable track system that allows it to climb stairs and travel up to 12.9 kilometers per hour.

(...)
http://www.scientificamerican.com/artic ... S_20110324

[atomez]

... mas já deviam ter "enterrado" aquilo.

O problema é que nem conseguem chegar lá perto...

A coisa não está nada bem no reator 3, o que tem plutónio.

Dangerous core breach suspected at Japan reactor

PM calls situation "very grave and serious" as emergency work is halted for radiation checks

OKYO (AP) — A suspected breach in the core of a reactor at the stricken Fukushima nuclear plant could mean more serious radioactive contamination, Japanese officials revealed Friday, as the prime minister called the country's ongoing fight to stabilize the plant "very grave and serious."

A somber Prime Minister Naoto Kan sounded a pessimistic note at a briefing hours after nuclear safety officials announced what could be a major setback in the urgent mission to stop the plant from leaking radiation, two weeks after a devastating earthquake and tsunami disabled it.

"The situation today at the Fukushima Dai-ichi power plant is still very grave and serious. We must remain vigilant," Kan said. "We are not in a position where we can be optimistic. We must treat every development with the utmost care."

The uncertain situation halted work at the nuclear complex, where dozens had been trying feverishly to stop the overheated plant from leaking dangerous radiation. The plant has leaked some low levels of radiation, but a breach could mean a much larger release of contaminants.

Suspicions of a possible breach were raised when two workers waded into water 10,000 times more radioactive than is typical and suffered skin burns, the Nuclear and Industrial Safety Agency said.

However, though damage cannot be ruled out, the cause remained unclear, spokesman Hidehiko Nishiyama told reporters.

"It is possible there may be damage somewhere in the reactor," he said, adding that a leak in the plumbing or the vents could also be to blame.

Nuclear expert James Acton told CBS' "The Early Show" that if the reactor core has in fact been breached, "this creates the possibility of a much larger release of radiation into the environment than we have seen to date. But I think it's still worth emphasizing that the chance of a catastrophic release of radiation on the scale of Chernobyl is still very low, even at this point."

[tava3]

Segundo a rtpn, o Japão pode vir a subir o nivil do acidente em fukushima para 6, principalmente por causa do reator 3, que pode estar pior do que imaginavam. Não sei se é por orgulho nacional ou se é para tirar peças, mas já deviam ter "enterrado" aquilo.

[MarcoAntonio]

Os últimos desenvolvimentos incluem:

> Três trabalhadores na central nuclear afectados pela radiação, por contacto com água contaminada no reactor 3 (dois transportados ao Hospital).

> A sugestão das autoridades Japonesas a evacuação voluntária aos que se situam entre os 20 e 30Km de distância da central nuclear, em virtude do prolongamento da situação.

[habanero04]

Já ouvi falar que os sismos se vão propagar através da cintura de fogo do pacífico. Parece que também já houve qualquer coisa em Myanmar, mas ainda não encontrei a notícia para aqui meter.

[superimpecavel]

E agora houve mais um sismo de 7.0 na Tailandia...

[habanero04]

[MarcoAntonio]

Resumo dos últimos desenvolvimentos:

Latest developments:

* Nuclear plant still emitting radiation but source unclear, says IAEA. The UN atomic watchdog says Japan has not given some information relating to one reactor.

* Smoke and steam seen rising from two of the most threatening reactors, No.2 and No.3, denting hopes of immediate progress in bringing them under control.

* Core of reactor No. 1 also a worry with temperature touching 380-390 Celsius (715-735 Fahrenheit), plant operator says. Reactor built to run at a temperature of 302 C (575 F).

* Engineers have re-established power cables to all six reactors and have started a pump at one of them to cool overheating fuel rods. Lighting had been restored at one of the control rooms, local media said.

(REUTERS)

As mesmas matérias também aqui:

http://www.reuters.com/article/2011/03/ ... SS20110322

[sombrio]

Pequenas partículas radioactivas foram detectadas na Islândia.

árias fontes diplomáticas afirmaram hoje que foram detectadas na Islândia quantidades minúsculas de partículas radioactivas. Estas podem ser provenientes da central nuclear japonesa de Fukushima, danificada pelo terramoto e posterior tsunami de 11 de Março, de acordo com o “El Mundo”.

Fontes esclareceram que os pequenos resíduos de iodo, detectados por uma rede de estações de observação internacional, atravessaram o Oceano Pacífico e chegaram ao Atlântico através do norte da América. Porém, as partículas são demasiado insignificantes para causar prejuízos na saúde humana.

A Organização do Tratado de Proibição Completa dos Ensaios Nucleares, organismo da ONU com sede em Viena, possui 63 estações em todo o mundo para observar essas partículas, uma das quais se situa em Reiquiavique.

O Departamento de Energia e a Agência de Protecção do Meio Ambiente dos Estados Unidos confirmou que na semana passada foram encontradas também na Califórnia partículas de radioactividade minúsculas. Em Washington, no Alaska e no Canadá também.

[MarcoAntonio]

Resumo dos últimos desenvolvimentos:

Latest developments:

* Nuclear plant still emitting radiation but source unclear, says IAEA. The UN atomic watchdog says Japan has not given some information relating to one reactor.

* Smoke and steam seen rising from two of the most threatening reactors, No.2 and No.3, denting hopes of immediate progress in bringing them under control.

* Core of reactor No. 1 also a worry with temperature touching 380-390 Celsius (715-735 Fahrenheit), plant operator says. Reactor built to run at a temperature of 302 C (575 F).* Engineers have re-established power cables to all six reactors and have started a pump at one of them to cool overheating fuel rods. Lighting had been restored at one of the control rooms, local media said.

(REUTERS)

As mesmas matérias também aqui:

http://www.reuters.com/article/2011/03/ ... SS20110322

[Quico]

Caro LTCM: como sempre, directo e incisivo!

Pena estas coisas simples serem sempre demasiadamente "complexas" para serem compreendidas (quanto mais explicadas) pelos media.

Abraço.

[LTCM]

[MarcoAntonio]

Alguem comenta esta energia ?

http://energyfromthorium.com/

É uma área de investigação com vários países a estudar e tentar explorar essa hipótese, incluindo aqueles dois que têm dos planos nucleares mais ambiciosos presentemente: a China e a Índia.

Supostamente o Thorium oferece várias vantagens sobre o Uranio nomeadamente a sua grande abundância, maior eficiência na produção de energia e a menor produção de resíduos radioactivos.

[Batmax]

Alguem comenta esta energia ?

http://energyfromthorium.com/

[MarcoAntonio]

Plutonium... a nova paranóia.

Circulam na internet informações e até artigos bastante extravagantes sobre o Plutonio, utilizadas em diversas centrais nucleares na mistura conhecida por MOX, basicamente uma mistura de uranio e plutonio (isótopo 239), ao ponto de existirem referências a tratar-se da mais perigosa substância conhecida pelo homem.

Um exemplo neste artigo:

http://www.businessinsider.com/japan-nu ... mox-2011-3

Contudo, uma rápida pesquisa permite descobrir que o artigo e outras afirmações de semelhante teor que correm a net como "um só atomo de plutónio pode matar", alertando para o perigo obscuro do plutonio estão bastante incorrectas ou francamente exageradas.

Uma fonte que se poderá considerar neutra:

http://en.wikipedia.org/wiki/Plutonium#Precautions

Toxicity

Isotopes and compounds of plutonium are dangerous due to their radioactivity. Contamination by plutonium oxide (spontaneously oxidized plutonium) has resulted from a number of military nuclear accidents where nuclear weapons have burned.[85]

The alpha radiation plutonium emits does not penetrate the skin but can irradiate internal organs when plutonium is inhaled or ingested.[32] The skeleton, where plutonium is absorbed by the bone surface, and the liver, where it collects and becomes concentrated, are at risk.[31] Plutonium is not absorbed into the body efficiently when ingested; only 0.04% of plutonium oxide is absorbed after ingestion.[32] What plutonium is absorbed into the body is excreted very slowly, with a biological half-life of 200 years.[86] Plutonium passes only slowly through cell membranes and intestinal boundaries, so absorption by ingestion and incorporation into bone structure proceeds very slowly.[87][88]

Plutonium is more dangerous when inhaled than when ingested. The risk of lung cancer increases once the total dose equivalent of inhaled radiation exceeds 400 mSv.[89] The U.S. Department of Energy estimates that the lifetime cancer risk for inhaling 5,000 plutonium particles, each about 3 microns wide, to be 1% over the background U.S. average.[90] Ingestion or inhalation of large amounts may cause acute radiation poisoning and death; no human is known to have died because of inhaling or ingesting plutonium, and many people have measurable amounts of plutonium in their bodies.[76]

The "hot particle" theory in which a particle of plutonium dust radiates a localized spot of lung tissue has been tested and found false – such particles are more mobile than originally thought and toxicity is not measurably increased due to particulate form.[87]

However, when inhaled, plutonium can pass into the bloodstream. Once in the bloodstream, plutonium moves throughout the body and into the bones, liver, or other body organs. Plutonium that reaches body organs generally stays in the body for decades and continues to expose the surrounding tissue to radiation and thus may cause cancer.[91]

Several populations of people who have been exposed to plutonium dust (e.g. people living down-wind of Nevada test sites, Hiroshima survivors, nuclear facility workers, and "terminally ill" patients injected with Pu in 1945–46 to study Pu metabolism) have been carefully followed and analyzed.

These studies generally do not show especially high plutonium toxicity or plutonium-induced cancer results.[87]

"There were about 25 workers from Los Alamos National Laboratory who inhaled a considerable amount of plutonium dust during the 1940's; according to the hot-particle theory, each of them has a 99.5% chance of being dead from lung cancer by now, but there has not been a single lung cancer among them."[92][93]

Plutonium has a metallic taste.[94]

Deixo também um paper sobre a toxicidade do plutónio:

http://muller.lbl.gov/pages/PlutoniumToxicity.pdf


.

[MarcoAntonio]

Da reuters:

Main developments:

- The World Health Organization says the detection of radiation in food is a more serious problem than first expected, and food contamination is not a localized problem. It says, however, there is no evidence of contaminated food from Fukushima reaching other countries.

The operator of the stricken Fukushima plant said a small trace of radiation had been found in the Pacific sea waters nearby, but officials stressed the levels were minute and posed no immediate danger.

China and South Korea say they will toughen radioactivity tests on imports of Japanese food, and Japan tells four prefectures near the nuclear plant to halt shipments of spinach.

Government also bans milk shipments from Fukushima province.

Government says Japanese food produced outside the nuclear crisis zone is safe.

Official death toll from earthquake and tsunami 8,450 with 12,931 missing. Police say more than 15,000 feared dead in Miyagi prefecture alone.

The U.N. atomic agency chief said that Japan's nuclear situation remained very serious but that he had no doubt the country would "effectively overcome" the crisis.

Também existe uma referência anterior a que o operador teria começado a bombear água para um reactor, mas a informação é vaga e não é claro de que reactor estão a falar.


Este é ainda o último update e resumo conforme é apresentado pela IAEA:

"1. Current Situation

We are seeing some steady improvements, but the overall situation at the Fukushima Daiichi nuclear power plant remains very serious. High levels of contamination have been measured in the locality of the plant.

The restoration of electrical power to Unit 2, which we reported yesterday, is good news. AC power is available and an electrical load check to pumps, etc. is currently on-going. Work on the restoration of off-site power to Units 3 and 4 is also underway.

Seawater is still being injected into the reactor pressure vessels of Units 1, 2 and 3.

Pressure in the reactor pressure vessel and the containment vessel drywell at Unit 3, which had been rising yesterday, has again fallen.

Water is being sprayed periodically into the spent fuel pools at Units 2, 3 and 4. The Agency still lacks data on water levels and temperatures in the spent fuel pools at Units 1, 2, 3 and 4.

Following the restoration of cooling at Units 5 and 6, temperatures in the spent fuel pools continue to decline.

2. Radiation Monitoring

As I reported yesterday, the IAEA radiation monitoring team took measurements at distances from 56 to 200 km from the Fukushima nuclear power plant. At two locations in Fukushima Prefecture gamma dose rate and beta-gamma contamination measurements have been repeated. These measurements showed high beta-gamma contamination levels. Measurements by the IAEA and the Japanese authorities were taken at the same time and locations. The Japanese and independent IAEA measurements gave comparable results.

Measurement of gamma dose rate and beta-gamma contamination were taken on 20 March at more locations. The dose-rate results ranged from 2-160 microsieverts per hour, which compares to a typical natural background level of around 0.1 microsieverts per hour. High levels of beta-gamma contamination have been measured between 16-58 km from the plant. Available results show contamination ranging from 0.2-0.9 MBq per square metre.

Further measurements are needed to assess possible contamination beyond the area currently monitored - both closer to the facility and further way. We have no contamination measurements showing that that contamination levels are high at greater distances than 58 km from the plant, but this cannot be excluded.

I have no further information available regarding the measurement of alpha radiation. As I reported yesterday, from the measurements taken within the evacuation zone (20 km), no significant alpha radiation had been detected at that time.

In the coming days, the IAEA monitoring team will continue to take measurements in the Fukushima prefecture. We are seeking data from Japan on radioactivity contamination measurements for the rest of Japan.

Some results on the monitoring of foodstuffs have been made available by Japan to the IAEA and FAO. Results provided recently by the Japanese authorities range up to 55 000 Bq per kg of I-131 in samples of Spinach taken in in the Ibaraki Prefecture. These high values are significantly above Japanese limits for restricting food consumption (i.e. 2 000 Bq/kg). I understand that the Japanese Government is actively considering relevant precautionary measures and has instructed four Prefectures (Ibaraki, Totigi, Gunma, Fukushima) to refrain, for the time being, from distributing two types of vegetables (spinach and kakina) from these Prefectures and milk from Fukshima.

3. Agency Activities

The Director General briefed the Board of Governors today on the outcome of his visit to Tokyo."

[MarcoAntonio]

A situação continua a evoluir de forma muito lenta, sem grandes progressos (avanços ou retrocessos). À parte dos reactores 5 e 6, a situação nos edifícios dos restantes reactores de Daiichi não se pode considerar estabilizada...


Resumo dos mais recentes desenvolvimentos:

> Durante o dia de hoje detectou-se fumo cinzento de dois reactores, o que levou à evacuação temporária da central por precaução. Não se detectou porém subida de radiação.

> Nos depósitos de combustível nuclear gasto do reactor 4 foi bombeado betão para protecção contra emissão de radiação.

> Todos os reactores já têm alimentação novamente. Mas como já sublinhei várias vezes, é incerto o resultado prático uma vez que tudo está dependente do estado do restante equipamento como tubagem, dispositivos de controlo, etc.

> Vão-se detectando níveis de radiação em diversas situações mas, como problema ou ameaça à saúde pública, é ainda muito localizado em torno da central. No que diz respeito a produtos alimentares, começaram a ser implementadas restrições na zona em torno da central de Daiichi.



Aqui fica a ultima notícia da reuters cobrindo a situação no Japão:

Radiation fears grow in disaster-struck Japan

By Shinichi Saoshiro and Kiyoshi Takenaka
TOKYO | Mon Mar 21, 2011 12:51pm EDT


(Reuters) - Global anxiety rose over radiation from Japan's earthquake damaged nuclear plant even as engineers had some success in the battle to avert disaster from the world's worst atomic crisis since Chernobyl.


The high-stakes drama at the battered Fukushima nuclear power complex is playing out while the Asian nation grapples with the rising death toll from the March 11 double disaster of an earthquake and tsunami. Officials estimate at least 21,000 people are dead or missing.

Technicians working inside an evacuation zone round the stricken plant on Japan's northeast Pacific coast have finally managed to attach power cables to all six reactors and started a water pump at one of them to cool overheating nuclear fuel rods.

"We see a light for getting out of the crisis," an official quoted Prime Minister Naoto Kan as saying, allowing himself some rare optimism in Japan's toughest moment since World War II.

Underlining the dangers, however, smoke rose briefly from two damaged reactors, forcing workers to evacuate for a while.

Away from the plant, mounting evidence of radiation in vegetables, water and milk spread jitters among Japanese and abroad despite officials' assurances levels were not dangerous.

The operator of the stricken plant, Tokyo Electric Power Company, said a small trace of radiation had been found in the Pacific sea waters nearby, but said levels were very low and posed no immediate danger.

"It's a lot more serious than anybody thought in the early days when we thought that this kind of problem can be limited to 20 to 30 kilometers," Peter Cordingley, spokesman for the World Health Organisation's (WHO) regional office, told Reuters.

"It's safe to suppose that some contaminated produce got out of the contamination zone."

However, Cordingley said there was no evidence of contaminated food reaching other countries from the Fukushima complex, which lies 240 km (150 miles) north of Tokyo.

Japan has urged some residents near the plant to stop drinking tap water after high levels of radioactive iodine were detected. It has also stopped shipments of milk, spinach and another local vegetable called kakina from the area.

"Radiation levels exceeding provisional standards have been found (in some products)," Chief Cabinet Secretary Yukio Edano said. "What I want the people to understand is that their levels are not high enough to affect humans. Eating these products just a couple of times would not affect people's health."

Experts say readings are much lower than around Chernobyl after the 1986 accident in Ukraine. Some warned against panic.

"You would have to eat or drink an awful lot to get any level of radiation that would be harmful," said Laurence Williams, professor of nuclear safety at the John Tyndall Institute in Britain.

"We live in a radioactive world -- we get radiation from the earth, from the food we eat. It's an emotive subject and the nuclear industry and governments have got to do a lot more to educate people."


There were no major reports of contaminated food in Tokyo, a city of about 13 million where many are staying indoors or wearing face masks. Some expatriates and locals left last week right after the accident.

Japan is a net importer of food, but has substantial exports -- mainly fruit, vegetables, dairy products and seafood -- with its biggest markets in Hong Kong, China and the United States.

JITTERS ABROAD

China said it is monitoring food imports from Japan but also took a swipe against panic by jailing a man for 10 days for spreading rumors about contamination of its waters.

State media said the computer company worker, who had urged people to avoid sea products for a year, was also fined 500 yuan ($76.13) and had confessed to "deep awareness of his mistake."

South Korea is expanding inspection to processed and dried agricultural Japanese food, from just fresh produce.

And in Taiwan, a top Japanese restaurant is offering diners a radiation gauge in case they are nervous about the food.

The United States is distributing potassium iodide to American personnel in Japan as a precaution against radiation exposure and "out of an abundance of caution" should the treatment be needed, a travel warning said.

The prospects of a nuclear meltdown in the world's third-biggest economy - and its key position in global supply chains especially for the automobile and technology sectors - rattled investors worldwide last week and prompted rare joint currency intervention by the G7 group of rich nations.

Damage is estimated at around $250 billion, making it the world's costliest ever natural disaster.

Japan's economic growth is expected to depress in the first half before reconstruction kicks in.

Tokyo's markets were closed for a holiday on Monday, but global stocks rose as risk appetite returned following progress in resolving the nuclear crisis. The yen slid on speculation of more Group of Seven intervention.

In a symbolic boost for Japan, billionaire investor Warren Buffett said the earthquake and tsunami were an "enormous blow" but in fact presented a "buying opportunity."

"It will take some time to rebuild. But it will not change the economic future of Japan. If I owned Japanese stocks, I would certainly not be selling them," Buffett said.

DEVASTATION

The official death toll - 8,805 by Tuesday morning - is certain to keep rising, with another 12,654 reported missing.


Police say more than 15,000 people probably died in Miyagi prefecture, one of four that took the brunt of the tsunami.

The 9.0-magnitude quake and ensuing 10-meter (32-ft) tsunami obliterated towns, which are now wastelands of mud and debris, leaving more than 350,000 people homeless.

Japanese are famed for their resilience, though, and there is little of the social chaos or looting that often accompany major global disasters.

In one devastated northern town, Rikuzentakata, rebuilding has even begun to help families living on mats in cramped shelters, separated from neighbors only by cardboard.

Steel structures, with walls and wood floors, have been erected at a hilltop school, to provide temporary housing.

Nearly 9.5 million foreigners visited Japan last year.

But, like Korean housewife Jin Hye-ryun who canceled a planned visit in May, many tourists are re-thinking.

"Safety is not guaranteed," she said. "Besides, think about people dying there. No one wants to go there to have fun."

(Additional reporting by Paul Eckert and James Topham in Tokyo; Yoko Kubota and Chang-ran Kim in Rikuzentakata; Jon Herskovitz and Chisa Fujioka in Kamaishi; Sui-Lee Wee in Beijing; Jungyoun Park in Seoul; Alister Doyle in Oslo; Writing by Andrew Cawthorne and Jason Szep, editing by Miral Fahmy)

[atomez]

Fumo a sair dos reatores 2 e 3, e é fumo escuro.

Isto são más notícias, quer dizer que não é vapor de água e pode tratar-se de um meltdown...

[atomez]

[atomez]

Na prefeitura de Ibaraki, a sul de Fukushima, detectam-se radiações "bastante" acima do normal, entre 2 a 3 microSv/h em alguns pontos, não o suficiente para causar danos relevantes à saúde pública.

Entretanto, noticia da Reuters acerca dos níveis de radiação detectados em produtos alimentares na zona de Fukushima:

O problema com a radiação nos alimentos é que com a sua propagação na cadeia alimentar as concentrações de radiação vão aumentando.

[sombrio]

<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/OdhfV-8dbCE" frameborder="0" allowfullscreen></iframe>

[MarcoAntonio]

Leituras mais actualizadas de níveis de radiação na zona em torno da central de Fukushima Daiichi (mas fora dos 20Km de exclusão):

http://www.mext.go.jp/component/english ... 2_2019.pdf


Aqui também é possivel seguir a radiação em diversas prefeituras:

http://www.bousai.ne.jp/eng/

Na prefeitura de Ibaraki, a sul de Fukushima, detectam-se radiações "bastante" acima do normal, entre 2 a 3 microSv/h em alguns pontos, não o suficiente para causar danos relevantes à saúde pública.


Entretanto, noticia da Reuters acerca dos níveis de radiação detectados em produtos alimentares na zona de Fukushima:

IAEA concerned about Fukushima food radiation

By Michael Shields and Fredrik Dahl
VIENNA | Sun Mar 20, 2011 4:13pm EDT

(Reuters) - The radioactive contamination of some food near Japan's stricken nuclear plant has become a concern even as authorities report progress in their battle to prevent a meltdown at the site, U.N. officials said on Sunday.

"There have been some positive developments in the last 24 hours but overall the situation remains very serious," said Graham Andrew, a senior official of the International Atomic Energy Agency (IAEA).

He was speaking at a news conference after Japan restored power to some units at the crippled nuclear reactor in a race to avert disaster at the plant wrecked by an earthquake and tsunami that hit Japan on March 11, killing thousands of people.

In addition, workers have successfully placed two other reactor units into "cold shutdown," with cooling systems stable and under control, the IAEA said.

"Japanese authorities have notified the IAEA of progress at the Fukushima Daiichi nuclear power plant," the Vienna-based nuclear agency said in a statement on its website.

But cases of contaminated vegetables, dust and water have raised new fears in Japan. The government has prohibited the sale of raw milk from Fukushima prefecture and spinach from a nearby area. It is considering further restrictions on food.

The IAEA confirmed that in some areas iodine 131 -- a radioactive isotope -- had been found in milk and freshly grown vegetables "significantly above the levels set by Japan for restricting consumption of these food products," Andrew said.

LOCAL PROBLEM

"The contamination of food and water is a concern," another IAEA official, Gerhard Proehl, told the news conference. He said the situation must be monitored carefully.

Measurements at a location about 46 km from the plant showed iodine 131 levels in milk up to 15 times above the level suitable for infants, he said. For spinach, detected levels were also many times above the limit.

Proel said Iodine 131 decays quickly and is not a long-term concern, but another radioactive element called caesium 137 "could stay in the soil for quite a long time" and could potentially be absorbed by plants.

Andrew described the food contamination as "a very localized phenomenon at the moment as far as we know" and also said that food produced in other countries had not been affected.

Asked whether there may be any trade implications, U.N. food agency official David Byron said national authorities were responsible for food production, distribution and sale.

"That doesn't mean the importing countries aren't doing anything as well," said Byron, who is currently seconded to the IAEA. "One way or another it is either being controlled by the Japanese, which I assume aren't shipping anything at this point, or being monitored ... by the importing control authority."

Last week, Japanese authorities recommended that people who have evacuated the area near the Fukushima plant should take stable iodine as a precaution, the IAEA said on Saturday.

Taken as pills or syrup, stable (non-radioactive) iodine can be used to help protect against thyroid cancer in the event of radiation exposure in a nuclear accident.

(Editing by Kate Kelland)

[MarcoAntonio]

Radiação em perspectiva:



Fontes:
http://xkcd.com/radiation/sources.html

[MarcoAntonio]

Food samples show raised radiation
19 March 2011
ORIGINALLY PUBLISHED: 12.52pm GMT

Radiation levels exceeding the Japanese government-set level have been detected in samples of milk and spinach collected in the region of the Fukushima nuclear power plant. However, the levels measured are said to pose no immediate threat to health.

Higher than limit levels of radiation were detected in samples of milk by authorities yesterday evening, chief cabinet secretary Yukiyo Edano reported. The milk samples had been collected within Fukushima Prefecture at a location more than 30 kilometres from the damaged Fukushima Daiichi plant.

This morning, six samples of spinach collected in Ibaraki Prefecture, neighbouring to the south of Fukushima Prefecture, were found to have higher levels of radiation. The prefectural boundary is some 65 km from the nuclear power plant.

Edano said that the levels of radiation detected exceed the limits stipulated as provisional regulation values under the national Food Sanitation Law. These limits have been set in accordance with International Committee on Radiation Protection's recommendations.

The limits are based on the amount of food concerned assuming that these amounts would be consumed throughout one’s entire life, Edano said. He stressed that the radiation measured from the samples poses no immediate threat to health. In the case of the milk samples, even if consumed for one year, the radiation dose would be equivalent to that a person would receive in a single CT scan. The levels found in the spinach were much lower, equivalent to one-fifth of a single CT scan.

The Ministry of Health, Labour and Welfare, as well as the prefectural governments, will continue to monitor and analyse food samples and determine the exact location where contaminated samples are found. Edano said that, assuming the higher radiation levels found in food are associated with emissions from the Fukushima plant, the Japanese government will consider taking necessary actions. These could include a ban on the shipment of foodstuffs or setting limits to the intake of such foods.

Researched and written
by World Nuclear News

Último report, reactor a reactor:

http://www.jaif.or.jp/english/aij/11031 ... us-15e.pdf

Desenvolvimentos:

> Abertura de buracos no topo dos edifícios dos reactores 5 e 6 para evitar explosões de hidrogénio;

> Níveis de radiação no exterior da central sobem um pouco (364.5 microSv/h);

> Continuam as operações para restabelecer energia em vários reactores.



E o último update da Reuters:

Japan nuclear rescue advances

(Reuters) - Engineers enjoyed some success in their mission to stop disaster at Japan's tsunami-damaged power plant, though evidence of small radiation leaks highlighted perils from the world's worst nuclear crisis since Chernobyl 25 years ago.


Three hundred technicians have been battling inside a danger zone to salvage the six-reactor Fukushima plant since it was hit by an earthquake and tsunami that also killed 7,508 people and left 11,700 more missing in northeast Japan.

The unprecedented multiple crisis will cost the world's third largest economy nearly $200 billion in Japan's biggest reconstruction push since post-World War II.

It has also set back nuclear power plans the world over.

Encouragingly for Japanese transfixed on the work at Fukushima, the situation at the most critical reactor -- No. 3 which contains highly toxic plutonium -- appeared to come back from the brink after fire trucks doused it for hours.

Work also advanced on bringing power back to water pumps used to cool overheating nuclear fuel.

"We are making progress ... (but) we shouldn't be too optimistic," said Hidehiko Nishiyama, deputy-generalat Japan's Nuclear Safety Agency.

Engineers attached a power cable to the No.1 and No. 2 reactors, hoping to restore electricity later in the day. They also hope to reach No. 3 and 4 soon to test turning the pumps on.

If successful, that could be a turning point in a crisis already rated as bad as America's Three Mile Island accident in 1979. If not, drastic measures may be required such as burying the plant in sand and concrete as happened at Chernobyl after the world's worst nuclear reactor disaster in 1986.

Cooling systems have been restored at the least critical of the six reactors, No. 5 and 6, using diesel generators.

"It appears that the situation has somewhat stabilized but it is still very severe," said Bo Stromberg, an analyst at the Swedish Radiation Safety Authority.

On the negative side, evidence has begun emerging of radiation leaks from the plant, including into food and water.

Though public fear of radiation runs deep, and anxiety has spread as far as the Pacific-facing side of the United States, health officials say levels so far are not alarming.

Traces exceeding national safety standards were, though found in milk from a farm about 30 km (18 miles) from the plant and spinach grown in neighboring Ibaraki prefecture.

TAP WATER AFFECTED

Tiny levels of radioactive iodine have also been found in tap water in Tokyo, one of the world's largest cities about 240 km (150 miles) to south. Many tourists and expatriates have already left and residents are generally staying indoors.

The sample contained 1.5 becquerals per kg of iodine 131, well below the tolerable limit for food and drink of 300 becquerals per kg, the government said.

Japan said the traces so far found posed no risks.

Yet U.N. atomic watchdog the International Atomic Energy Agency said Japan was considering whether to halt all food product sales from Fukushima prefecture.

The first discovery of contaminated food since the March 11 disaster is likely to heighten scrutiny of Japanese food exports, especially in Asia, their biggest market.

Prime Minister Naoto Kan, who has kept a low profile during the crisis except for shouting at plant operator Tokyo Electric Power Co (TEPCO), sounded out the opposition about forming a government of national unity to deal with the crisis.

But the largest opposition party rejected that.

MOVING EARTH

Showing the incredible power of the 9.0 magnitude earthquake, the largest in tremor-prone Japan's recorded history, Oshika peninsula in Miyagi prefecture shifted a whole 5.3 metres (17 ft) east and its land sank 1.2 metres (4 ft).

In contrast to the generally negative images so far, one video emerged showing the crew of a Japanese coastguard vessel successfully riding a massive wave by turning the bow directly at the wall of waters.

The quake and ensuing 10-meter high tsunami devastated Japan's north east coastal region, wiping towns off the map and making some 360,000 people homeless in a test for the Asian nation's reputation for resilience and social cohesion.

Food, water, medicine and fuel are in short supply in some parts, and near-freezing temperatures are not helping.

The grim search for bodies continues.

"This morning my next door neighbor came crying to me that she still can't find her husband. All I could tell her was, 'We'll do our best, so just hold on a little longer,'" said fire brigade officer Takao Sato in the disaster zone.

About 257,000 households in the north still have no electricity and at least one million lack running water.

In the face of mounting criticism, plant operator TEPCO's president issued a public apology for "causing such great concern and nuisance."

The crisis has been an unwelcome reminder for Japanese of their previous nuclear nightmare, the 1945 atomic bombs in Hiroshima and Nagasaki.

(Additional reporting by Nathan Layne, Kiyoshi Takenaka, Ealine Lies Mayumi Negishi, Tomasz Janowski in Tokyo, and Yoko Kubota and Chang-ran Kim in Rikuzentakata; Alister Doyle in Oslo; Writing by Andrew Cawthorne and Jason Szep. Editing by Jeremy Laurence.)

[MarcoAntonio]

O pior dos cenários eles nunca o vão anticipar por causa do pânico, (...)

Isso é uma questão política, os engenheiros e cientistas de outros países nada têm que ver com isso e a função deles seria precisamente avisar para antecipar...

(...) é impraticavél uma evacuação em massa em tempo util.

Portanto, o correcto era antecipar, prevenir. Como? Alargando já a área de evacuação.

Mas vamos supor um dos piores cenários, imaginem que o nucleo do reator 3, cujo o edificio é o que está em pior estado e o que tem o plutónio, explode e lança para atmosfera uma nuvem de radiação com valores do tipo chernobyl, na casa das centenas de sieverts.

Aquilo não está em condições de explodir.

A calor contido nos reactores é já uma parcela muito pequena. É possivel fundir, arder material, etc mas explodir só se for explosões de hidrogénio como as que já ocorreram, não uma explosão do reactor (nem tão pouco dos depósitos de combustível gasto)...