Japonya’da hâlihazırda 54 tane nükleer santral var.
Kullanılmış yakıtlar hakkındaki genel politika, yeniden işlenen kadar depolanması (santralde) şeklinde
Japonya’da nükleer tehdit seviyesi 5ten 7’ye çıkarıldı. Otoritelerin gerçekleri gizlemesi bir yere kadar olabiliyor. Ekte, TEPCO tarafından hazırlanmış bir sunum var, esas tehlikeyi gösteren “spent fuel rods” ile ilgili rakamlara göz atmanızı tavsiye ederim. Mühendis arkadaşlardan özellikle yorum yapmalarını rica edebilir miyiz?
Globalresearch sitesinden aşağıdaki haberi aldım:
Geçen hafta TEPCO ve Japon hükümeti, hasarlı Fukishima reaktörlerindeki sızıntının artçı depremlerden etkilenmediğini söylemişlerdi. NHK haberlerine göre ise durum farklı:
Fabrika sorumlusu, Perşembe akşamını gerçekleşen depremin tesise zarar vermediğini fakat bir numaralı reaktörün ısısının gece yarısı öncesi çok yükseldiğini söyledi. Dün saat 7 sularında (Amerika) reaktör ısısı 223 derecedeydi, deprem sonrası 40 derece yükseldi. Cumartesi sabahı ısı 240 dereceye gerilemişti. Bunlara ilave olarak Japon hükümeti, bir numaralı reaktördeki radyasyon düzeyinin 100 sievert/saat olduğunu söyledi. Radyasyon seviyesi gelişimi aşağıdaki grafikte gösterildi:
Çernobil patladıktan sonra bu oran saatte 300 sievert olarak ölçülmüştü. Bir numaralı reaktör, bunlara rağmen tesisteki diğer reaktörlerden daha kötü durumda olmayabilir, ekteki sunumda da göreceğiniz üzere fukushima’daki nükleer materyalin yanında Çernobil cüce kalıyor. ZeroHedge sitesinden Tyler Durden (İsim tanıdık mı?) Japon hükümetinin 100 sievert sonrasında raporlamayı sansürlediğini yazıyor. Bu beklenmedik bir durum değil. NYtimes’daki haberlere göre: Yetkililer, kötü durumun bir panik yaratmaması için detayları açıklamıyorlar. 1993-99 yılları arasında bölgede çalışan Robert Alvarez’e göre kimse bölgeye gitmek istemiyor. Gizli raporlar ise durumun vahametinin üst düzeye tırmandığını gösteriyor.
07 Nisan tarihli yazı, washingtos blog sitesinden :
Ongoing Cover Up of Nuclear Crisis By Governments and Nuclear Power Companies
I’ve previously documented that Japanese seismologists and nuclear engineers warned years ago that the risks of a large-scale nuclear accident in Japan were high, with one Japanese seismologist warning in 2004 that the risk of a nuclear accident was:
Like a kamikaze terrorist wrapped in bombs just waiting to explode.
I also showed that whistleblowers have been ignored:
Years before Fukushima engineer Mitsuhiko Tanaka blew the whistle on the fact that Tepco covered up a defective containment vessel, the above-quoted Japan Times article blew the whistle:
Yoichi Kikuchi, a Japanese nuclear engineer who also became a whistle-blower, has told me personally of many safety problems at Japan’s nuclear power plants, such as cracks in pipes in the cooling system from vibrations in the reactor. He said the electric companies are “gambling in a dangerous game to increase profits and decrease government oversight.”
[Kei Sugaoka, a Japanese-American senior field engineer who worked for General Electric in the United States, who previously blew the whistle on Tepco’s failure to inform the government of defects at the reactors] agreed, saying, “The scariest thing, on top of all the other problems, is that all nuclear power plants are aging, causing a deterioration of piping and joints which are always exposed to strong radiation and heat.”
Kikuchi and Sugaoka were ignored. Just like American whistle-blowers are being ignored.
And after the March 11th disaster, the Japanese government has been covering up information.
Indeed, nuclear engineer Arnie Gundersen points out that American and Japanese governments and nuclear companies are covering up many core facts concerning the Japanese nuclear crisis.
NYTimes Haberi (5 Nisan)
U.S. Sees Array of New Threats at Japan’s Nuclear Plant
By JAMES GLANZ and WILLIAM J. BROAD
United States government engineers sent to help with the crisis in Japan are warning that the troubled nuclear plant there is facing a wide array of fresh threats that could persist indefinitely, and that in some cases are expected to increase as a result of the very measures being taken to keep the plant stable, according to a confidential assessment prepared by the Nuclear Regulatory Commission.
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Workers at the Fukushima Daiichi nuclear station are dealing with new challenges.
Japan Earthquake and Tsunami Multimedia
· Company Says Radioactive Water Leak at Japan Plant Is Plugged (April 6, 2011)
· Crisis Saddles Village With Unwanted Notoriety (April 6, 2011)
· Radiation Errors Erode Confidence in Power Company (April 6, 2011)
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Among the new threats that were cited in the assessment, dated March 26, are the mounting stresses placed on the containment structures as they fill with radioactive cooling water, making them more vulnerable to rupture in one of the aftershocks rattling the site after the earthquake and tsunami of March 11. The document also cites the possibility of explosions inside the containment structures due to the release of hydrogen and oxygen from seawater pumped into the reactors, and offers new details on how semimolten fuel rods and salt buildup are impeding the flow of fresh water meant to cool the nuclear cores.
In recent days, workers have grappled with several side effects of the emergency measures taken to keep nuclear fuel at the plant from overheating, including leaks of radioactive water at the site and radiation burns to workers who step into the water. The assessment, as well as interviews with officials familiar with it, points to a new panoply of complex challenges that water creates for the safety of workers and the recovery and long-term stability of the reactors.
While the assessment does not speculate on the likelihood of new explosions or damage from an aftershock, either could lead to a breach of the containment structures in one or more of the crippled reactors, the last barriers that prevent a much more serious release of radiation from the nuclear core. If the fuel continues to heat and melt because of ineffective cooling, some nuclear experts say, that could also leave a radioactive mass that could stay molten for an extended period.
The document, which was obtained by The New York Times, provides a more detailed technical assessment than Japanese officials have provided of the conundrum facing the Japanese as they struggle to prevent more fuel from melting at the Fukushima Daiichi plant. But it appears to rely largely on data shared with American experts by the Japanese.
Among other problems, the document raises new questions about whether pouring water on nuclear fuel in the absence of functioning cooling systems can be sustained indefinitely. Experts have said the Japanese need to continue to keep the fuel cool for many months until the plant can be stabilized, but there is growing awareness that the risks of pumping water on the fuel present a whole new category of challenges that the nuclear industry is only beginning to comprehend.
The document also suggests that fragments or particles of nuclear fuel from spent fuel pools above the reactors were blown “up to one mile from the units,” and that pieces of highly radioactive material fell between two units and had to be “bulldozed over,” presumably to protect workers at the site. The ejection of nuclear material, which may have occurred during one of the earlier hydrogen explosions, may indicate more extensive damage to the extremely radioactive pools than previously disclosed.
David A. Lochbaum, a nuclear engineer who worked on the kinds of General Electric reactors used in Japan and now directs the nuclear safety project at the Union of Concerned Scientists, said that the welter of problems revealed in the document at three separate reactors made a successful outcome even more uncertain.
“I thought they were, not out of the woods, but at least at the edge of the woods,” said Mr. Lochbaum, who was not involved in preparing the document. “This paints a very different picture, and suggests that things are a lot worse. They could still have more damage in a big way if some of these things don’t work out for them.”
The steps recommended by the nuclear commission include injecting nitrogen, an inert gas, into the containment structures in an attempt to purge them of hydrogen and oxygen, which could combine to produce explosions. On Wednesday, the Tokyo Electric Power Company, which owns the plant, said it was preparing to take such a step and to inject nitrogen into one of the reactor containment vessels.
The document also recommends that engineers continue adding boron to cooling water to help prevent the cores from restarting the nuclear reaction, a process known as criticality.
Even so, the engineers who prepared the document do not believe that a resumption of criticality is an immediate likelihood, Neil Wilmshurst, vice president of the nuclear sector at the Electric Power Research Institute, said when contacted about the document. “I have seen no data to suggest that there is criticality ongoing,” said Mr. Wilmshurst, who was involved in the assessment.
The document was prepared for the commission’s Reactor Safety Team, which is assisting the Japanese government and the Tokyo Electric Power Company. It says it is based on the “most recent available data” from numerous Japanese and American organizations, including the electric power company, the Japan Atomic Industrial Forum, the United States Department of Energy, General Electric and the Electric Power Research Institute, an independent, nonprofit group.
Başka bir yazı:
Extremely High Radiation Levels in Japan: University Researchers Challenge Official Data
An independent assessment by university researchers from Kyoto University and Hiroshima University finds that the radiation levels are not being correctly reported by the Japanese government nor TEPCO.
Anti-nuclear protesters holding placards shout slogans as they march in Tokyo April 10, 2011. The placard read, “No Need Nuclear Power Plant” and “Change Energy Policies”. Japan is struggling to regain control of the Fukushima Daiichi nuclear plant after a massive earthquake and tsunami devastated its northeast on March 11, and is facing a major humanitarian and economic crisis.
The Fukushima nuclear disaster is often touted as being of less concern than the Chernobyl disaster. We are reserving judgement on that, but generally feel the situation is far worse. We base this on facts, not opinion. This latest article only increases our awareness of how much has been hidden from us, and how the officials are spinning the story. Of great concern are their findings that outside of the recommended 30 kilometer zone, extremely high radiation has been detected. They are 400 times normal radiation levels and exceed what normal evacuation procedures would consider dangerous.
Protesters hold placards against nuclear power plant as they took to the streets in a rally against nuclear power and its development, in Tokyo, on Sunday, April 10, 2011, after a devastative earthquake and tsunami crippled the Fukushima Daiichi nuclear complex in northeastern Japan last month. The placards held by the protesters show leaders of countries of the three major nuclear power industries, from left, U.S. President Barack Obama, French President Nicolas Sarkozy and Japanese Prime Minister Naoto Kan.
Although the American government suggested a 80 km evacuation zone after the March 11 radiation leak, the Japanese only mandated a 20 km zone, with a recommendation that people leave within the 30 km zone. Yesterday was Sunday in Japan, and the American government downgraded their recommendation to 40km. This is quite remarkable considering that high levels were known to be occuring at Iitake village, which is outside the 30km evacuation zone, and given this latest disclosure from the Asahi news agency.
A worker wearing protective suit points at his rubber boots to show the level of water being submerged at the second basement floor of the crippled Fukushima Daiichi Nuclear Power Plant in Fukushima prefecture, northern Japan in this handout photo taken April 8, 2011, and released by Japan’s Nuclear and Industrial Safety Agency. Japan will pump radioactive water into the sea from the crippled nuclear plant until Sunday, a day later than previously planned, its nuclear safety agency said. Picture taken April 8, 2011. Mandatory Credit.
Radiation was detected in ranges from “590,000 to 2.19 million becquerels/cubic meter outside the 30km range.” These numbers far exceed the levels at Chernobyl which ranged below 550,000 becquerels/cubic meter. Of most concern is that both measurements were of the same radioactive isotope: Cesium-137, which has a half-life of 30 years. To this day, wide areas of the area surrounding Chernobyl are ghost towns. No humans can live there without causing extremely strong health affects and birth defects. Numerous documentaries have been made concerning children born with deformities and mentally incapacitated during this period, and people who suffered from the effects of the Cesium poisoning.
The Japanese government is considering revising their radiation limits on agricultural products, fishing, water, soil, and even human exposure given the increase in radiation. With no hope in sight of alleviating the tragedy, and with only the news that this will continue for months or years, we can expect further increases in radiation readings and accumulation in the food chain.
While Chernobyl was an enormous unprecedented disaster, it only occurred at one reactor and rapidly melted down. Once cooled, it was able to be covered with a concrete sarcophagus that was constructed with 100,000 workers. There are a staggering 4400 tons of nuclear fuel rods at Fukushima, which greatly dwarfs the total size of radiation sources at Chernobyl. The Daiichi plant has a total of six reactors. As yet there are no plans to concrete the structures since they are not cool yet, nor has TEPCO announced plans to do so. One can imagine the enormous manpower needed to construct and support six concrete sarcophagi: 600,000 workers? I doubt the Fukushima 50 can do it alone. It should be noted that today the government revised worker exposure from 100 milliSeverts to 250 milliSieverts. Outside contractors working on the facility refused the higher standard.
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