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MessageSujet: Re: Les informations   Les informations - Page 36 EmptySam 26 Nov 2011 - 21:09

0.116 Bq par litre
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMar 29 Nov 2011 - 9:54

Hi,

"TEPCO says no explosion occurred at No.2 reactor

"The operator of the damaged Fukushima Daiichi nuclear power plant says there was no explosion at the No. 2 reactor, denying an earlier report that there was. But the company says it is still unable to determine how and why radioactive substances were released from the reactor.

NHK has obtained Tokyo Electric Power Company's interim report on the nuclear accident that was triggered by the earthquake and tsunami on March 11th.

The report includes findings from a study that the utility launched in June to analyze how the accident occurred and how workers responded to it.

The report says that almost all electricity sources for the reactors were lost at once following the tsunami.

As a result, multiple safety functions were also lost, causing meltdowns from the No. 1 to the No. 3 reactors.

TEPCO analyzed seismographic data recorded within the plant in the early morning of March 15th, 4 days after the disaster, when a large blast was reportedly heard near the containment vessel of the No. 2 reactor.

The company concluded in the report that there was no explosion at the No. 2 reactor, and that a blast at the No. 4 reactor was mistakenly believed to have occurred at the No. 2.

Later that day, pressure inside the No. 2 reactor vessel dropped sharply, and radiation levels near the plant's main gate rose above 10 millisieverts per hour, then the highest level so far.
The interim report fails to specify how the leakage occurred at the containment vessel, just saying that gas in the vessel was somehow released into the air.
Tuesday, November 29, 2011 09:58 +0900 (JST)"

http://www3.nhk.or.jp/daily/english/20111129_10.html

-----

Expert urges probe of No.2 reactor leak
The spike in radiation levels following unspecified trouble at the No.2 reactor on March 15th was much more prominent than on March 12th or 14th, when explosions hit the No.1 and No.3 reactors.

Shinichiro Kado, an associate professor at the University of Tokyo, calls the reactor containment vessel "a final fortress" for keeping radioactive substances trapped, and a "cornerstone" for the integrity of a nuclear plant.

Kado says a breach of the vessel is extremely grave.

He says TEPCO needs to clarify how radioactive substances were released, by cross-referencing data on reactor conditions and patterns of radioactive dispersion in the atmosphere.
Tuesday, November 29, 2011 09:58 +0900 (JST)

http://www3.nhk.or.jp/daily/english/20111129_11.html
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 14:28

Bonjour,
Selon NHK Wolrd, TEPCO a publié les résultats de l'analyse de l'état du combustible fondu dans les réacteurs.
Réacteur 1 : fuite en dehors du RPV avec érosion du béton à l'interieur du CPV sur 65 cm de profondeur. L'épaisseur de béton restante sur la section la plus faible serait de 37 cm avant d'atteindre l'enceinte du CPV.
Réacteur 2 : 57 % du combustible fondu avec fuite en dehors de RPV
Réacteur 3 : 63 % du combustible fondu avec fuite en dehors de RPV
http://www3.nhk.or.jp/daily/english/20111130_39.html
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 16:22

Bonjour
Allez TEPCO ! Encore un effort pour que l'analyse de l'état du combustible mentionne une petite sortie. Vous y êtes presque.
KLOUG
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 17:13

Tepco a donc annoncé qu'il n'y a pas eu d'explosion au réacteur n°2, et dans la foulée, que le coeur a fondu et qu'il y a eu fuite du combustible.
Le processus qui a amené à la fusion du coeur n'aurait-il pas dû provoquer une explosion? ou bien est-ce que ça signifierait que le RPV était déjà endommagé par le séisme?
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 17:20

Bonsoir
Il est possible que le séisme est fait plus des dégâts que prévu.
KLOUG
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 21:18

Nuclear inspectors agree on early notification system
http://ajw.asahi.com/article/behind_news/politics/AJ201111300030
Japan, China and South Korea’s nuclear energy authorities agreed on Nov. 29 to establish an early notification system to share information on accidents at nuclear power plants.
The new system will be aimed at addressing criticism leveled in the wake of the accident at the Fukushima No. 1 nuclear power plant that Japan failed to keep other nations adequately informed.
Officials from Japan's Nuclear and Industrial Safety Agency (NISA) and their counterparts in China and South Korea have yet to decide what particular issues will be covered by the early warning system and how information will be transmitted.
The three nations already submit reports of accidents at nuclear power plants to the International Atomic Energy Agency (IAEA). While those reports can be obtained by other states through the IAEA, it can take about a month to get some information.
Diplomatic channels also proved inadequate for transmitting information during the crisis, increasing calls for a formal system with clear rules.
A particular concern of the Chinese authorities following the Fukushima disaster was Japan’s slowness in informing neighboring nations of Tokyo Electric Power Co.'s release of water contaminated with radiation into the sea after the nuclear accident.
According to officials at Japan’s Agency for Natural Resources and Energy, South Korea had 20 nuclear reactors and China had 11 as of 2010. Japan, South Korea and China account for about 77 percent of the nuclear plants in Asia. China is currently constructing a number of new reactors.
Japan has reported between 10 to 20 accidents and problems to the IAEA every year, including incidents with the lowest rating of 0 on the International Nuclear and Radiological Event Scale (INES), which are seen as carrying no safety significance. Japanese officials said the new early notification system would likely carry all such events.
By TAKASHI SUGIMOTO / Staff Writer
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 23:11

Bonsoir,
L'étude de Andreas Stohl a un peu conclu dans le sens dégâts dus au seisme ; puis j'ai retrouvé aussi cet article
http://www.letemps.ch/Facet/print/Uuid/6ed08616-5015-11e0-93ec-7b0ac0b11c86/Des_ex-cadres_nippons_accusent
Pour être honnêtes, la "sismicité" n'y est pour rien...
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyMer 30 Nov 2011 - 23:29

Hi,

Institute of Applied Energy: Corium Could Be 2 Meters Deep into Concrete
TEPCO's worst-case scenario (here and here) pales in comparison with the analysis by the Institute of Applied Energy, also presented on November 30 at the workshop held by the Nuclear and Industrial Safety Agency.

From what Yomiuri Shinbun reported (01:01AM JST 12/1/2011):

国の委託を受けて実施したエネルギー総研の解析では、1号機は燃料の85%、2、3号機は70%が格納容器に落下。炉心を取り囲むステンレス製の大型構造物「シュラウド」が損傷したり、格納容器の床のコンクリートも最大2メートル侵食したりしていると指摘した。そのため、コンクリートに支えられた圧力容器が傾いている可能性もあるとした。

The analysis done by the Institute of Applied Energy commissioned by the national government, 85% of fuel dropped to the Containment Vessel in Reactor 1, and 70% of fuel dropped to the Containment Vessels in Reactors 2 and 3. The researchers at the Institute pointed out the possibility of the damage to the stainless-steel shroud that surrounds the fuel core, and of the corium having eaten away the concrete floor of the Containment Vessel up to 2 meters deep. Because of that, they also said it was possible that the RPV got tilted.

Yomiuri doesn't specify which Reactor the Institute of Applied Energy was talking about, but my guess is Reactor 1.

Some nuclear experts have suggested that if the corium had escaped from the RPV it would spread out flat and evenly on the pedestal and be easily cooled by water. Well, even TEPCO admits that may not the case as far as the shape and the location of the corium is concerned (they do say the corium is cooled), and the Institute of Applied Energy says the corium could be 2 meters deep into the concrete.

My totally amateur 2 cents are that the concrete foundation may have cracked in the earthquake, and that it is possible that the crack or cracks are there in the pedestal. So, even if the corium wanted to spread out thin and flat, it would find those cracks and go there. Once the core-concrete reaction starts, it would be a positive feedback loop; the temperature gets higher not just from the contact with the corium but from the core-concrete reaction, the hole in the concrete would get bigger, and more corium would go into the bigger hole.

http://ex-skf.blogspot.com/
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 16:51

<BLOCKQUOTE class="postcontent restore ">

Bon du nouveau.
Tepco lâche encore quelques infos qui confirment bien le percement des cuves par le corium et l'attaque de la drywell sans encore aller jusqu'à reconnaître son éventuel percement pour l'instant.
Tepco semble donc désormais donner raison à certains scientifiques qui avaient peut-être eu tord d'avoir raison avant eux.
De toutes façons Tepco précise qu'il ne s'agit que de résultats de simulation et qu'ils n'auront rien de visuel avant plusieurs années.

Autre info
L'hospitalisation d'urgence du directeur de la centrale

et pas de bol mais cela n'a probablement rien avoir d'après les " experts" sur d'autres forum

La nouvelle leucémie aigue du présentateur japonais qui se vantait de consommer de préférence les produits de Fukushima par solidarité.

http://www.africanouvelles.com/varietes/loisirs/1414-japon-celebre-presentateur-atteint-de-leucemie-apres-avoir-mange-en-direct-des-legumes-de-fukushima-a-la-tele.html

</BLOCKQUOTE>
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 17:20

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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 18:04

Bonjour,

À stefreggae, ce lien fonctionne :

https://www.youtube.com/watch?feature=player_embedded&v=24eGVuK4G4M

J'en profite pour poser cette petite question, qui est à la manœuvre sur le site ENENEWS ? http://enenews.com/

Aucune rubrique du genre : "qui sommes-nous ?" mais peut-être me trompé-je faute d'une observation incomplète de ce site ?

La caméra http://www.tepco.co.jp/en/nu/f1-np/camera/index-e.html ne fonctionne pas.
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 18:06

Bonsoir
Difficile de se prononcer.
Quant à dire qui est à la manœuvre sur le site ENENEWS, je ne sais pas ?
La caméra fonctionne (j'ai réussi à me connecter).
KLOUG
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 18:14

Cette caméra plus large fonctionne aussi: http://pon.bex.jp/all2.html
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http://cartoandco.eklablog.com/
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 18:16

Et ici http://enformable.com/fukushima-daiichi/ les archives vidéos sur Fukushima
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyJeu 1 Déc 2011 - 18:36

Sur le site de Kyodo News :

"TEPCO study shows water level in spent fuel pool was dangerously low" 02:11 2 December

http://english.kyodonews.jp/
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 13:53

Hi,

Fukushima's Reactor 1 Meltdown Was Worse Than We Realized

"A new simulation of the meltdowns at the Fukushima Dai-ichi nuclear power station found that the situation was even worse than previously thought. It now appears that nearly all the nuclear fuel in reactor 1 melted through the first line of defense, the steel reactor vessel, and made a serious dent in the next protective layer.
(The analysis is only available in Japanese at this time, but we'll update the post when/if it comes out in English. The source of the figures in this post is a brief summary from World Nuclear News.)
TEPCO, the utility that owns the Fukushima plant, ran new calculations of the rate at which the nuclear fuel melted in reactors 1, 2, and 3. These three reactors were in service at the time of the 11 March earthquake and tsunami, and although they automatically shut down following the earthquake, the tsunami knocked out all power at the facility and thus prevented cooling systems from removing the nuclear fuel's residual heat.
As extensively documented in our feature article, "24 Hours at Fukushima," reactor 1 suffered the greatest breakdown. That 40-year-old reactor lost all its emergency cooling systems immediately following the tsunami, while the backup cooling systems at reactors 2 and 3 functioned for a couple of days.
The new analysis from TEPCO suggests that almost all of reactor 1's fuel melted through the steel reactor vessel and dropped down into the primary containment vessel below. (In the image above, the fuel sludge is the brown blob.) The primary containment vessel, a steel structure in the shape of an upside-down light bulb, has concrete at the bottom of the bulb. TEPCO's analysis found that the fuel melted through 70 centimeters of that concrete. However, that still left 190 centimeters of intact concrete between the melted fuel and the steel boundary of the primary containment vessel. In addition, the secondary containment building has 760 centimeters of concrete that stand between the primary containment and the earth below.
At reactors 2 and 3, the simulation found that smaller amounts of fuel melted holes in the pressure vessels and dropped down to the concrete in the primary containment vessel.
It should be noted that this information comes from a computer model of the fuel's behavior, and it may be inaccurate. With the intense levels of radiation around the reactors, there's no way yet to measure the actual location of the fuel.
But it's also worth remembering that TEPCO's earliest announcements about the Fukushima Dai-ichi accident said that there had been no melting of the nuclear fuel. Later they admitted there had been significant melt, but said the fuel had all remained in the reactor vessels. While the company has no doubt been scrambling to get accurate information in an ever-changing and extremely dangerous disaster scene, I'm looking forward to results of the Japanese government's investigation into what TEPCO knew, and when they knew it."

http://spectrum.ieee.org/tech-talk/energy/nuclear/fukushimas-reactor-1-meltdown-was-worse-than-we-realized
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 13:54

All N-fuel may have fallen to outer vessel / TEPCO: Up to 68 tons likely melted in No. 1 reactor, eroding concrete of containment unit
The Yomiuri Shimbun

Almost all the nuclear fuel inside the No. 1 reactor of the crippled Fukushima No. 1 nuclear power plant has melted, damaging the pressure vessel and eroding the concrete bottom of the containment vessel by up to 65 centimeters, the plant's operator has found.

Tokyo Electric Power Co. released its latest analysis Wednesday on the cores of the plant's Nos. 1 to 3 reactors, based on temperature, water levels and other data. TEPCO said the fuel inside the reactors has melted to various degrees following the March 11 earthquake and tsunami.

The No. 2 reactor's fuel is up to 57 percent melted, while that of the No. 3 reactor is up to 63 percent melted, TEPCO's analysis has shown.

TEPCO has made the latest analysis to judge to what degree the fuel has cooled, as well as to ascertain if it can achieve its year-end target of a cold shutdown of the reactors, as stipulated in the timetable the utility company and the government have compiled to bring the nuclear crisis under control.

Following the March 11 earthquake and tsunami, water injection at the No. 1 reactor was suspended for about 14 hours, resulting in damage more serious than in the Nos. 2 and 3 reactors, which had water injection suspended for six to seven hours, according to TEPCO.

The nuclear fuel at the No. 1 reactor melted as its temperature reached nearly 3,000 C at one time, TEPCO estimated. In the No. 1 reactor, TEPCO believes, almost all of the about 68 tons of fuel melted. This has not only seriously damaged the bottom of the steel pressure vessel enough to create holes, but the fuel has also fallen to the concrete bottom of the containment vessel, eroding it by up to 65 centimeters.

Only 37 centimeters of concrete remains between the fuel and the vessel's outermost steel wall in the most damaged area, TEPCO said.

Without water, the No. 1 reactor's fuel temperature was more than high enough to have melted everything inside the pressure vessel, not only the fuel itself but also the fuel control rods, the utility said.

TEPCO currently maintains a steady supply of water to the three reactors, enabling the No. 1 reactor to always have about 40 centimeters of cool water at the bottom of the containment vessel, enough to cover the melted fuel, according to the utility.

Both the government and the utility said the three reactors are experiencing no problems in maintaining cooling functions.

However, the melted fuel likely will be a major hurdle in removing fuel from the troubled reactors in the decommissioning process, which is expected to take more than 30 years.

(Dec. 2, 2011)

http://www.yomiuri.co.jp/dy/national/T111201006092.htm
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 13:59

Sur le site du New York Times cette fois :

http://www.nytimes.com/2011/12/01/world/asia/meltdown-in-japan-may-have-been-worse-than-thought.html?_r=1

Study Shows Worse Picture of Meltdown in Japan
By HIROKO TABUCHI
Published: November 30, 2011

"TOKYO — Molten nuclear fuel may have bored into the floor of at least one of the reactors at the stricken Fukushima Daiichi nuclear power plant, the complex’s operator said Wednesday, citing a new simulation of the accident that crippled the plant in March.

The simulation suggested that the meltdown may have been more severe than had previously been thought.

Soon after an earthquake and a tsunami on March 11 knocked out cooling systems at the power plant, nuclear fuel rods in three of its six reactors overheated and slumped, the operator, the Tokyo Electric Power Company, has said.

In the No. 1 reactor, the overheated fuel may have eroded the primary containment vessel’s thick concrete floor, and it may have gotten almost within a foot of a crucial steel barrier, the utility said the new simulation suggested. Beneath that steel layer is a concrete basement, which is the last barrier before the fuel would have begun to penetrate the earth.

Some nuclear experts have warned that water from a makeshift cooling system now in place at the plant may not be able to properly cool any nuclear fuel that may have seeped into the concrete. The new simulation may call into question the efforts to cool and stabilize the reactor, but the Tokyo Electric Power Company, or Tepco, says it is not worried more than eight months after the accident.

The findings are the latest in a series of increasingly grave scenarios presented by Tepco about the state of the reactors. The company initially insisted that there was no breach at any of the three most-damaged reactors; it later said that there might have been a breach, but that most of the nuclear fuel had remained within the containment vessels.

“This is still an overly optimistic simulation,” said Hiroaki Koide, an assistant professor of physics at the Kyoto University Research Reactor Institute, who has been a vocal critic of Tepco’s lack of disclosure of details of the disaster. Tepco would very much like to say that the outermost containment is not completely compromised and that the meltdown stopped before the outer steel barrier, he said, “but even by their own simulation, it’s very borderline.”

“I have always argued that the containment is broken, and that there is the danger of a wider radiation leak,” Mr. Koide said. “In reality, it’s impossible to look inside the reactor, and most measurement instruments have been knocked out. So nobody really knows how bad it is.”

Still, a spokesman for Tepco, Junichi Matsumoto, said Wednesday that the nuclear fuel was no longer eating into the concrete, and that the new simulation would not affect efforts to bring the reactors to a stable state known as a “cold shutdown” by the end of the year.

“The containment vessel as a whole is being cooled, so there is no change to our outlook,” Mr. Matsumoto said at a news conference.

The nuclear accident at the Fukushima Daiichi plant, the worst since Chernobyl, triggered fuel meltdowns at three of its six reactors and a huge radiation leak that has displaced as many as 100,000 people. The Japanese government has said some areas around the plant will be uninhabitable for decades.

Tepco based the simulation on projections of decay heat released by the nuclear fuel and other estimates. The results suggest that the uranium fuel rods at the No. 1 reactor were most badly damaged, Mr. Matsumoto said, because it lost cooling water before the other two reactors did. The fuel rods were exposed for several hours before fire trucks could pump in emergency seawater.

Because the simulation suggests that heat released as a result of radioactive decay “far overwhelmed” the effect of the cooling water, he said, and because temperatures in the inner pressure vessel that originally housed the fuel are thought to have dropped quickly, Tepco now assumes that “100 percent of the fuel at Unit 1 has slumped” into the outer primary containment vessel.

In addition, the simulation suggests that the fuel bored more than two feet into the concrete, Mr. Matsumoto said.

At Units 2 and 3, the initial cooling efforts were more successful, he said, and a smaller amount of fuel is thought to have escaped the pressure vessels and into the primary containment vessels."

Euh ... quelque chose dans la presse française ?
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 14:19

on peut trouver 3 articles récents sur le blog scientifique de Libé : http://sciences.blogs.liberation.fr/
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 14:24

Se pourrait-il que les variations de radioactivité visibles sur l'instrument défectueux http://atmc.jp/plant/rad/?n=1 soient en réalité liées à des successions de phases ou le corium est sous eau et de phases ou celui-ci est découvert ? TEPCO venant semble-t-il de certifier qu'il y avait en permanence 40cm d'eau dans l'enceinte de confinement (ce qui est peu).
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 14:56

si tu relis le fil d'informations sur le corium, certains membres du forum apportaient des débuts d'explication... j'ai en mémoire la métaphore de la pâte à pain.
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 17:33

Bonsoir
Ce qui m'amuse un peu, c'est la précision des chiffres.
On sait bien qu'ils sont issus d'une simulation mais du coup le sens physique (au sens de l'analyse critique en physique) disparait. On repompe directement la valeur. 37 et pourquoi pas 38,543 ou 36...
KLOUG
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptyVen 2 Déc 2011 - 20:48

Tepco Says Fukushima Reactors Withstood Earthquake Jolt

"Updates with comment from company in sixth paragraph.)

Dec. 2 (Bloomberg) -- Tokyo Electric Power Co. said critical units of its Fukushima nuclear plant withstood shaking from the March 11 earthquake, Japan’s strongest on record, before being swamped by the tsunami that followed.

The surge knocked out cooling systems that led to meltdowns in three reactors at the Fukushima Dai-Ichi plant and the worst radiation release since Chernobyl in 1986, Tepco concluded in a report on the disaster. About 160,000 people were forced to flee the contamination and many areas near the plant may be uninhabitable for decades, government officials have said.

“This isn’t the end of the story. Tepco’s analysis needs to be reviewed by independent experts,” Tadashi Narabayashi, a former reactor safety researcher at Toshiba Corp. and now a nuclear engineering professor at Hokkaido University, said by phone before the release of the report. “The utility has often made mistakes in simulations that analyzed what happened.”

The company’s findings will be followed at the end of the month by the release of a government report on its probe into the catastrophe, which is being led by engineering professor Yotaro Hatamura.

Tepco set up an internal committee headed by Vice President Masao Yamazaki in June to investigate the nuclear accident. The 130-page interim report is accompanied by a 314-page attached book on plant data, a 69-page chronology of events and other documents. It was released today in Tokyo.

Radiation Release

“We don’t know what the government committee will conclude in its investigation,” Yamazaki told reporters in Tokyo. “Even if it reaches a different conclusion, we will insist on the validity of our report.”

Tepco’s investigation concluded critical units of the station north of Tokyo weren’t significantly damaged by the quake because no unusual changes in the plant gauges were detected before the tsunami hit.

“The direct cause of the nuclear accident was the unprecedented tsunami,” an advisory body that reviewed the interim report said in a statement. Tepco’s lack of preparation made the crisis worse, the body led by Genki Yagawa, an honorary professor of Tokyo University, said.

A report in October from the Norwegian Institute for Air Research suggested there was “some structural damage to the reactor” during the earthquake that caused radiation to start leaking before the tsunami. The study was led by Andreas Stohl, an atmospheric scientist at the institute.

The Tepco committee probing the failures also found there was no explosion in the building of the No. 2 reactor. Three other reactor buildings were severely damaged by hydrogen explosions resulting from the melting of nuclear fuel.

--Editors: Aaron Sheldrick, Peter Langan"

http://www.businessweek.com/news/2011-12-02/tepco-says-fukushima-reactors-withstood-earthquake-jolt.html
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptySam 3 Déc 2011 - 11:37

Bonjour
Pour ceux qui veulent suivre les événements concernant les différents points lumineux enregistrés par les caméras :
http://fukushima.over-blog.fr/
Avec plein de questions : la taille des "feux", le floutage voire arrêt des caméras (ah la transparence de TEPCO !), présences de véhicules d'interventions, des signaux d'alarmes en haut des grues (?)...
Plutôt que réécrire le tout je vous conseille la lecture.
KLOUG
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MessageSujet: Re: Les informations   Les informations - Page 36 EmptySam 3 Déc 2011 - 12:44

Hi,

Workers at Japan nuclear plant recall tsunami desperation
By Harumi Ozawa (AFP) – 4 hours ago

TOKYO — The embattled operator of Japan's Fukushima Daiichi nuclear plant has released workers' accounts of the desperate moments surrounding the huge earthquake and tsunami that triggered an atomic crisis.
At a hearing into the March disaster, a chief operator described how he realised disaster had hit when lights flickered and went out, including those on the control panels, according to an interim report released Friday by the Tokyo Electric Power Co. (TEPCO).
"I came to realise a tsunami had hit the site as one of the workers rushed into the room, shouting 'Sea water is gushing in!'", the unnamed chief operator was quoted as saying.
"I felt totally at a loss after losing power sources," he said. "Other workers appeared anxious. They argued, and one asked: 'Is there any reason for us to be here when there is nothing we can do to control (the reactors)?'"
"I bowed and begged them to stay."
The 9.0-magnitude earthquake and subsequent tsunami on March 11 paralysed electrical and cooling systems at the nuclear power plant, triggering the world's worst nuclear crisis since Chernobyl 25 years ago.
Friday's interim report was the first to detail testimonies from workers, who were hailed as heroes in the weeks following the accident as they took extreme health risks to try to prevent a worse nuclear disaster.
They described attempts to release pressure from a reactor container by manually opening a ventilation valve.
"We put on the full protection gear but couldn't possibly let young workers do the task, as we had to go into an area where the radiation levels were high," one worker recalled.
"When I got to the place to open the valve, I heard eerie, deep popping noise from the torus (a donut-shaped structure at the bottom of the reactor)," he said.
"When I put one of my feet on the torus to reach the valve, my black rubber boot melted and slipped (due to the heat)."
The operators also spoke of dismal working conditions as they battled to stabilise the crippled plant.
"We experienced big aftershocks, and many times we had to run up a hill in desperation (fearing a tsunami) with the full-face mask still on," one worker said.
Another worker spoke of the race to lay power cables and bring back the supply of electricity, saying: "We finished the work (in one section) in several hours, although it usually requires one month or two."
"It was an operation we had to do in puddles, fearing electrification," the worker said.
Explosions and fires at the plant unleashed dangerous levels of radiation, forcing TEPCO to pull out hundreds of workers, leaving just a few dozen behind.
Those workers earned the nickname "the Fukushima Fifty", but that number eventually swelled again by thousands, including technicians sent from partners such as Toshiba and Hitachi.
They were tasked with keeping cooling water flowing into the six reactors at the plant, three of which eventually overheated and experienced meltdowns.
Despite a series of setbacks in the past nine months, the Japanese government and TEPCO say they remain on track to declare a cold shutdown later this month, about a month earlier than initially planned.
The atomic accident has not directly claimed any lives but has left tens of thousands of people displaced and rendered whole towns uninhabitable because of radiation, possibly for decades. The quake-tsunami killed about 20,000 people.
In a recent interview with AFP, Goshi Hosono, state minister in charge of nuclear accident settlement and prevention, hailed the plant workers for their battle to tame the crippled reactors.
"It was the emergency workers at the plant who have contributed to it the most," he said. "We are finally seeing the goal of cold shutdown in sight. The workers' efforts must be highly applauded."
But Hosono, when he visited the plant last month, also cautioned that 30 years' work remained to be done to dismantle the machinery.
Last month, then Fukushima Daiichi plant chief Masao Yoshida told state broadcaster NHK: "In the first week immediately after the accident I thought a few times 'I'm going to die.'"
Referring to a hydrogen explosion that tore apart the buildings around rectors 1 and 3, he said: "I thought it was all over."

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