Archives de novembre 2011

japanese government underestimates radiation risks

From: http://nuclear-news.net/2011/11/30/japanese-government-underestimates-radiation-risks/

Fukushima Radiation Risks “Severely Underestimated“: Greenpeace, November 29, 2011 Tokyo- (PanOrient News)Greenpeace today renewed its demand for the Japanese government to keep its nuclear reactors offline as simulation maps of potential accidents at Japan’s nuclear plants – used in the development of nuclear emergency response efforts – “are completely inadequate, and have not been updated since the Fukushima disaster.”

Following a Greenpeace freedom of information request on November 25, the Ministry of Education, Culture, Sports, Science and Technology (MEXT) released SPEEDI simulations of the radioactive contamination spread from all nuclear plants in Japan. Greenpeace said these maps show only extremely low releases of radioactivity over a 10km area around the plants in the event of meltdown, making any emergency response plan based on them totally insufficient should another severe disaster like the Fukushima Daiichi crisis occur…..

“The simulation of radioactive releases from the Ohi reactor for example, is scandalously inadequate. It foresees a radiation release in the order of 10,000 times less severe than what could happen during a major incident,” said Jan Vande Putte, Greenpeace International Nuclear Campaigner. “Similar over-optimistic scenarios have been used for reactors all over Japan. Hoping for the best is absolutely the wrong way to devise an emergency response plan.”…

Greenpeace met with officials from MEXT and the SPEEDI programme today, and they confirmed that the current simulations are limited to low-level releases, and that the system needed upgrading to cover larger releases and wider areas beyond 10km from the plants.

“The Fukushima Daiichi emergency response effort was slow, chaotic and insufficient, and it appears the Government has learned nothing from it so far,” said Junichi Sato, Greenpeace Japan Executive Director.
“These maps show that there is a strong risk of reactor restarts being pushed through without a proper, science-based assessment on the real risks being conducted, and without proper precautions being taken to protect the communities around the plants.”

Greenpeace is demanding that the Japanese government uses SPEEDI for what it was developed for, and run worst-case scenario simulations for all nuclear plants in Japan so there is a clear understand what effect a Fukushima Daiichi-type incident at other plants around Japan could have http://www.panorientnews.com/en/news.php?k=1471

http://nuclear-news.net/

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Japan Nuclear Accident Plans Still ‘Inadequate,’ Greenpeace Says

Nov. 30 (Bloomberg) — Japan’s plans for containing nuclear accidents are “completely inadequate” and haven’t been updated nearly nine months after the disaster at Fukushima, Greenpeace International said.

Government maps simulating a reactor meltdown project a release of low-level radiation only as far as 10 kilometers (6.2 miles), the environmental group said in a statement yesterday. The bulk of radioactive contamination extends as far as 30 kilometers from the leaking Fukushima plant, according to Japan’s science ministry. Some areas may be uninhabitable for decades, government officials have said.

Japan should keep nuclear plants offline until adequate plans are in place, Greenpeace said. More than 80 percent of the country’s reactors are either damaged or idled for repairs and safety checks after the March tsunami and earthquake caused meltdowns of three reactors at Tokyo Electric Power Co.’s Fukushima Dai-Ichi station. Atomic power provided about 30 percent of Japan’s energy before the catastrophe.

The government’s maps are based on “a radiation release in the order of 10,000 times less severe than what could happen during a major incident,” Jan Vande Putte, a nuclear campaigner with a degree in radiation protection from the University of Utrecht, said in the statement. “Hoping for the best is absolutely the wrong way to devise an emergency response plan.”

Greenpeace cited documents obtained in a freedom of information request to the Ministry of Education, Culture, Sports, Science and Technology.

Mapping Radiation

Japan’s system for projecting the spread of radiation, called SPEEDI, is limited to low-level releases and needs upgrading to cover areas beyond 10 kilometers, Greenpeace said, citing interviews with government officials it didn’t identify.

Yu Sumikawa, an official in charge of disaster management for the science ministry agreed the government’s projections on how far radiation would spread from Fukushima were inadequate.

“SPEEDI can’t be 100 percent accurate, but we need to improve its accuracy,” he said. The science ministry is requesting funds to expand the scope of SPEEDI.

“The Fukushima Daiichi emergency response effort was slow, chaotic and insufficient, and it appears the government has learned nothing from it,” Junichi Sato, Greenpeace Japan Executive Director, said in the statement. “There is a strong risk of reactor restarts being pushed through without a proper, science-based assessment on the real risks being conducted.”

http://www.businessweek.com/news/2011-11-30/japan-nuclear-accident-plans-still-inadequate-greenpeace-says.html

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Fukushima-STOP-Radioactivity

http://blogs.mediapart.fr/blog/uncas/261111/fukushima-radioactivity-long-time

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Inside Fukushima

http://ngm.nationalgeographic.com/2011/12/japan-nuclear-zone/inside-fukushima#/1

Japan’s nuclear disaster towns hold remote local elections

okuma japan

Workers arrive at the Fukushima Daiichi nuclear power station in Okuma, Japan. Local elections are being remotely held for the area, although it remains largely deserted. Photograph: David Guttenfelder/AP

They have been deserted for eight months, and could stay that way for years, their former inhabitants now scattered around north-east Japan.

But the towns of Okuma and Futaba, located in the shadow of the Fukushima Daiichi nuclear power plant, have shown that civic life must go on, even in the wake of a major nuclear accident. In one of the more surreal episodes of world democracy, tens of thousands were eligible to vote on Sunday for regional assemblies and mayors in towns that have all but ceased to exist.

Fukushima is the last of the three hardest-hit prefectures to go have gone to the polls since elections were postponed after the 11 March tsunami. Elections in Japan are usually characterised by early-morning speeches outside railway stations and last-ditch appeals for support from candidates perched atop campaign vehicles. Their faces, accompanied by pithy slogans, stare out from numerous billboards.

But none of that was evident in the 11 cities, towns and villages that lie inside the 12-mile exclusion zone imposed around Fukushima Daiichi in March.

Residents of Futaba and Okuma, which were electing mayors and assembly members on Sunday, have only been permitted brief visits home since the disaster to survey the damage and retrieve valuables and heirlooms.

Of the 80,000 people evacuated from the no-go zone, 58,000 are reportedly living in other prefectures, creating a logistical nightmare for officials who have had to oversee candidacy applications in temporary offices far from the election battlegrounds.

The absence of polling stations created a spike in the number of absentee ballots, forcing officials to extend the official campaign period by several days to give displaced residents time to size up the candidates and submit their ballot papers.

The campaign has been dominated by the slow pace of decontamination efforts and financial aid for the tens of thousands of people whose lives have been put on hold since March.

All of the parties and groups involved in the Fukushima assembly election said last month that they wanted nuclear power to be phased out. That degree of consensus may have kept voters away, however. As of 11am, the turnout was below 13%, according to Kyodo news agency.

For as long as they remain uninhabitable and their residents dispersed, the future of the contaminated areas will be clouded by uncertainty. According to a recent poll by Fukushima University, 27% of people living in the Futaba district said they had no intention of returning home. More than half of those aged below 35 said they planned to stay away.

That bodes ill for the area’s survival, the Mainichi Shimbun said in a recent editorial: « The results have demonstrated that many younger residents, who are supposed to play a key role in restoring their disaster-ravaged communities, have given up on returning to their neighbourhoods for fear of radiation contamination. »

http://www.guardian.co.uk/world/2011/nov/20/japan-nuclear-disaster-towns-elections?fb=optOut

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Future cancers from Fukushima plant may be hidden

Future cancers from Fukushima plant may be hidden

http://www.cbc.ca/news/health/story/2011/11/21/japan-nuclear-cancer-risk.html

Even if the Fukushima nuclear plant disaster, the worst accident in 25 years, leads to many people developing cancer, we may never find out.

Looking back on those early days of radiation horror, that may sound implausible.

But the ordinary rate of cancer is so high, and our understanding of theeffects of radiation exposure so limited, that any increase in cases from the Fukushima nuclear plant disaster may be undetectable.

Several experts inside and outside Japan told The Associated Press that cancers caused by the radiation may be too few to show up in large population studies, like the long-term survey just getting under way in Fukushima.

That could mean thousands of cancers under the radar in a study of millions of people, or it could be virtually none. Some of the dozen experts the AP interviewed said they believe radiation doses most Japanese people have gotten fall in a « low-dose » range, where the effect on cancer remains unclear.

The cancer risk may be absent, or just too small to detect, said Dr. Fred Mettler, a radiologist who led an international study of health effects from the 1986 Chernobyl disaster.

That’s partly because cancer is one of the top killers of people in industrialized nations. Odds are high that if you live long enough, you will die of cancer. The average lifetime cancer risk is about 40 percent.

In any case, the 2 million residents of Fukushima Prefecture, targeted in the new, 30-year survey, probably got too little radiation to have a noticeable effect on cancer rates, said Seiji Yasumura of the state-run Fukushima Medical University.

Yasumura is helping run the project.

« I think he’s right, » as long as authorities limit children’s future exposure to the radiation, said Richard Wakeford, a visiting epidemiology professor at the Dalton Nuclear Institute at the University of Manchester in England. Wakeford, who’s also editor of the Journal of Radiological Protection, said he’s assuming that the encouraging data he’s seen on the risk for thyroid cancer is correct.

The idea that Fukushima-related cancers may go undetected gives no comfort to Edwin Lyman, a physicist and senior scientist with the Union of Concerned Scientists, a group that advocates for nuclear safety. He said that even if cancers don’t turn up in population studies, that « doesn’t mean the cancers aren’t there, and it doesn’t mean it doesn’t matter. »

« I think that a prediction of thousands of cancer deaths as a result of the radiation from Fukushima is not out of line, » Lyman said. But he stressed that authorities can do a lot to limit the toll by reducing future exposure to the radiation. That could mean expensive decontamination projects, large areas of condemned land and people never returning home, he said. « There’s some difficult choices ahead. »

Japan’s Cabinet this month endorsed a plan to cut contamination levels in half within the next two years.

The plant was damaged March 11 by a tsunami triggered by a magnitude-9 earthquake. Japanese authorities estimate it leaked about one-sixth as much radiation as the Chernobyl accident. It spewed radioactive materials like iodine-131, cesium-137 and 29 others contaminating the water, soil, forests and crops for miles around.

So far, no radiation-linked death or sickness has been reported in either citizens or workers who are shutting down the plant.

But while the Fukushima disaster has faded from world headlines, many Japanese remain concerned about their long-term health. And many don’t trust reassurances from government scientists like Yasumura, of the Fukushima survey.

Many consumers worry about the safety of food from Fukushima and surrounding prefectures, although produce and fish found to be above government-set limits for contamination have been barred from the market.

Fukushima has distributed radiation monitors to 280,000 children at its elementary and junior high schools. Many children are allowed to play outside only two or three hours a day. Schools have removed topsoil on the playgrounds to reduce the dose, and the Education Ministry provided radiation handbooks for teachers.

Thousands of children have been moved out of Fukushima since the March disasters, mainly due to radiation fears.

Many parents and concerned citizens in and around Fukushima, some even as far as Tokyo, carry Geiger counters for daily measurement of radiation levels in their neighborhoods, especially near schools and kindergartens. The devices are probably one of the most popular electronics gadgets across Japan these days. People can rent them at DVD shops or drug stores in Fukushima.

Nuclear Regulator Dismissed Seismologist on Japan Quake Threat

Nov. 22 (Bloomberg) — Dismissed as a “nobody” by Japan’s nuclear industry, seismologist Katsuhiko Ishibashi spent two decades watching his predictions of disaster come true: First in the 1995 Kobe earthquake and then at Fukushima. He says the government still doesn’t get it.

The 67-year-old scientist recalled in an interview how his boss marched him to the Construction Ministry to apologize for writing a 1994 book suggesting Japan’s building codes put its cities at risk. Five months later, thousands were killed when a quake devastated Kobe city. The book, “A Seismologist Warns,” became a bestseller.

That didn’t stop Haruki Madarame, now head of Japan’s Nuclear Safety Commission, from dismissing Ishibashi as an amateur when he warned of a “nuclear earthquake disaster,” a phrase the Kobe University professor coined in 1997. Ishibashi says Japan still underestimates the risk of operating reactors in a country that has about 10 percent of the world’s quakes.

“What was missing — and is still missing — is a recognition of the danger,” Ishibashi said, seated in a dining room stacked with books in his house in a Kobe suburb. “I understand we’re not going to shut all of the nuclear plants, but we should rank them by risk and phase out the worst.”

Among Japan’s most vulnerable reactors are some of its oldest, built without the insights of modern earthquake science, Ishibashi said. It was only in the last four years that Japan Atomic Power Co. recognized an active fault line running under its reactor in Tsuruga, which opened in 1970 about 120 kilometers (75 miles) northeast of Osaka and close to a lake that supplies water to millions of people in the region.

New Fault Lines

Japan Atomic is reinforcing the plant to improve quake tolerance and believes it’s safe despite the discovery of new active faults lines in 2008, Masao Urakami, a Tokyo-based spokesman for the utility, said.

“We can’t respond to every claim by every scientist,” he said. “Standards for seismic ground motion are not decided arbitrarily, but are based on findings by experts assigned by the government.”

Reactor 1 at the Tsuruga plant, which had its license extended for 10 years in 2009, is one of 13 on Wakasa bay, a stretch of Sea of Japan coast that is home to the world’s heaviest concentration of nuclear reactors. The area is riddled with fault lines found in the last three or four years, according to Ishibashi.

Energy Review

In the first annual review of energy policy since the Fukushima disaster, the government on Oct. 28 approved a white paper calling for reduced reliance on nuclear power. The report also omitted a section on nuclear power expansion that was in last year’s review.

The government “regrets its past energy policy and will review it with no sacred cows,” the report said.

The white paper needs to be followed with action, Ishibashi said. “Changing the energy policy is a good thing, but I really do wonder if there will be follow-through,” he said.

Opinion polls show the Fukushima disaster has turned the majority of Japanese against nuclear power. Companies, meantime, are worried about higher costs and unstable electricity supply. The country has no oil reserves and 30 percent of Japan’s electricity supply came from atomic energy before March 11.

Japan without nuclear energy may add as much as 1.7 trillion yen ($22 billion) a year to the power bill for industry, the Japan Iron and Steel Federation said in July.

Threat to Move

Komatsu Ltd., the world’s No. 2 maker of construction machinery, has said it will move overseas if stable electricity supply isn’t guaranteed. Prime Minister Yoshihiko Noda said on Sept. 2 that some reactors shut down after the March disaster will have to restart to keep the economy going.

“These plants are a calculated risk,” says Tom Jordan, director of the Southern California Earthquake Center in Los Angeles. “Japan has been reasonably thoughtful but they obviously have problems with earthquakes and they have underestimated the risks. Still you have to ask the question: what is the risk of depending on other sources of power?”

Flipping through binders of press clippings in a black T- shirt and grey slacks, Ishibashi said he still remembers his fear of quakes when he was a boy. He slept with a flashlight next to his pillow in case he had to escape in the night.

While in college, a magnitude 7.5 earthquake off Japan’s coast killed dozens in the city of Niigata and sent shock waves through Ishibashi’s apartment in Tokyo.

Experts Needed

“There was a radio broadcast that night saying Japan didn’t have enough earthquake experts,” he said, adjusting his steel-rimmed glasses. “I decided I’d do that.”

It was 1964. Modern seismology was getting started and Japan was halfway through building its first nuclear reactor. By the time Ishibashi got his doctorate in seismology from the University of Tokyo 12 years later, there were 24 reactors running or under construction, including six at Tokyo Electric Power Co.’s Fukushima Dai-Ichi power station.

Seismologists at the time still focused on written records, rather than geological history, for clues about where and when quakes struck. And it wasn’t until 1977 that mainstream scientists had the tools to measure the size of quakes like the magnitude-9 that triggered the Fukushima disaster.

The Richter scale used before then went only to 8.5, or about 6 times less energy than the March 11 quake.

Significant Damage

“So all of a sudden everyone knew that, hey, there are magnitude-9 earthquakes in the world,” said Robert Geller, a professor of geophysics at the University of Tokyo. “They didn’t know that when they built the nuclear power plants at Fukushima or other plants from that era. But when that became known they should have done some rethinking.”

Minutes of a June 2009 trade ministry meeting on safety at the Fukushima Dai-Ichi plant show Tokyo Electric and the regulator ignored scientific findings that emerged after the power station was built.

“We didn’t think the damage would be that significant,” said Isao Nishimura, a manager at the utility’s nuclear earthquake resistance technology center, when asked at the meeting why its safety review omitted studies showing the area had a history of major earthquakes and tsunami.

Debate was cut short by an official from the Nuclear and Industrial Safety Agency, according to minutes of the meeting obtained by Bloomberg News. The regulator approved Fukushima Dai-Ichi’s safety report a month later, despite studies by Tohoku University geologist Koji Minoura in the 1990s that showed giant tsunami had hit Japan’s northeast coast three times in the last 3,000 years.

Russian Roulette

“That’s about one every 1,000 years on average,” said Geller. “If you’ve got a plant that runs 50 years, you have a 5 percent chance. You’re talking about Russian roulette.”

Disregard for the science extended to a government panel started in 2001 to revise seismic engineering standards for Japan’s nuclear plants, said Ishibashi. He quit the panel after five years of debate that he called rigged and unscientific.

The revised seismic standards didn’t reflect evidence that earthquakes could occur in areas where there were no signs of active faults. The omission allowed the utilities to carry on without undertaking expensive retrofits, Ishibashi says.

“The point I was trying to make was that if you’re going to have nuclear plants here in Japan, they should be built to withstand the most severe shaking that’s been observed,” he said, recalling the date he resigned from the panel in exasperation on Aug. 28, 2006. “They tried to chip away at that as much as they could,” he said.

Worst Case Scenario

Masanori Hamada, a Waseda University engineering professor who also served on the panel, said there were reasons for not adopting Ishibashi’s views.

“I understood what Ishibashi was saying, but if we engineered factoring in every possible worst case scenario, nothing would get built,” Hamada said. “What engineers look for is consensus from the seismologists and we don’t get that.”

The Fukushima disaster is forcing a rethink in the U.S. nuclear industry. A task force for the Nuclear Regulatory Commission on the disaster recommended in July that U.S. utilities re-evaluate earthquake hazards every 10 years.

“At this point there is no requirement to re-review basic seismic design information,” NRC spokesman Scott Burnell said by e-mail.

In June, Japan’s Nuclear Safety Commission instructed its experts to review guidelines for earthquake and tsunami defenses at nuclear plants.

License to Operate

There are no plans to introduce regular seismic reviews as the U.S. proposes, said a commission official, who was not authorized to speak to the media and declined to be identified.

“The nuclear industry has tended to give you a license and then once you have that license you are deemed safe,” said Norm Abrahamson, a seismologist at the University of California at Berkeley and an adviser at Pacific Gas & Electric Co., the state’s biggest utility.

“Nuclear plants are such huge investments that operators need some assurance of getting their money back,” Abrahamson said. “They’re looking for what they would call regulatory stability, but regulatory stability and scientific change don’t go hand in hand.”

Ishibashi says he didn’t start out as a critic of Japan’s nuclear industry. In 1976, when the then 31-year-old researcher at Tokyo University made his first important discovery — that a fault line west of Tokyo was much bigger than assumed — the risk to Chubu Electric Power Co.’s Hamaoka nuclear plant in Shizuoka prefecture didn’t occur to him. The plant had opened that year above the fault.

Fukushima Foretold

His view changed after a magnitude-6.9 quake killed more than 5,500 people on Jan. 17, 1995, and toppled sections of elevated expressway.

After a disaster that Japanese engineers had said couldn’t happen, the nuclear regulator didn’t immediately re-evaluate its construction standards. It said the plants were “safe from the ground up,” as the title of a 1995 Science Ministry pamphlet put it. Ishibashi decided to investigate.

The result was an article on Hamaoka published in the October 1997 issue of Japan’s Science Journal that reads like a post-mortem of the Fukushima disaster: A major quake could knock out external power to the plant’s reactors and unleash a tsunami that could overrun its 6-meter defenses, swamping backup diesel generators and leading to loss of cooling and meltdowns.

When the local prefecture questioned industry experts about Ishibashi’s paper, the response was that he didn’t need to be taken seriously.

Ishibashi a ‘Nobody’

“In the field of nuclear engineering, Mr. Ishibashi is a nobody,” Madarame said in a 1997 letter to the Shizuoka Legislature. Madarame, then a professor at the University of Tokyo school of engineering, is now in charge of nuclear safety in the country.

Requests made to Madarame’s office in October for an interview on his current views of Ishibashi’s work were declined.

On Oct. 24, Madarame was asked after a regular press briefing for the commission if he’d changed his opinion about Ishibashi.

“Because of the accident there’s a need to take another look at things, including the earthquake engineering guidelines, and we’re doing that,” he said. “Ishibashi contributed a lot to the revisions to the earthquake guidelines and his comments there are important.” He declined to comment further.

Hamaoka’s reactors, the subject of Ishibashi’s 1997 report, were shut in May after then-Prime Minister Naoto Kan went on television to publicly plead with Chubu Electric to close the plant. The utility estimates it will cost 100 billion yen and 18 months to build a seawall around the reactors.

Speaking Engagements

Now Professor Emeritus at Kobe University, Ishibashi said he hasn’t much time for hiking or other hobbies as his schedule is packed with speaking engagements.

The message he gives to business leaders and politicians is the focus on tsunami risk after Fukushima has deflected attention from the fundamental issue: The danger of having more than 50 nuclear reactors in one of the world’s most earthquake- prone countries.

At a private meeting with the Kobe Chamber of Commerce at a Chinese restaurant on July 31, Ishibashi planned to talk through a slide presentation on the risk associated with the 13 nuclear reactors on Wakasa Bay up the coast, nine of which are more than 30 years old.

The reactors, which keep factories running for companies including Panasonic Corp. and Kawasaki Heavy Industries Ltd. as well as powering the cities of Osaka, Kyoto and Kobe, are in an area that has had at least five magnitude-7 and magnitude-8 quakes over the last 500 years.

Ishibashi said he got through only a few of his 36 Power Point slides before his time was up and dinner started. He was seated at a round table next to the chairman of one of Japan’s biggest companies, who Ishibashi asked not be identified because the meeting was private.

“‘I know you want the reactors shut,’” he said the chairman told him. “‘But it can’t happen. We need the electricity.’”

http://www.businessweek.com/news/2011-11-22/nuclear-regulator-dismissed-seismologist-on-japan-quake-threat.html

Utility Reform Eluding Japan After Nuclear Plant Disaster

http://www.nytimes.com/2011/11/18/world/asia/after-fukushima-fighting-the-power-of-tepco.html?_r=2&smid=tw-nytimes&seid=auto

Architect of Fukushima’s Reactor 3 warns of massive hydrovolcanic explosion

November 21, 2011– TOKYO – Architect of Fukushima Daiichi Reactor 3, Uehara Haruo, the former president of Saga University had an interview on 11/17/2011. In this interview, he admitted Tepco’s explanation does not make sense, and that the China syndrome is inevitable. He stated that considering 8 months have passed since 311 without any improvement, it is inevitable that melted fuel went out of the container vessel and sank underground, which is called China syndrome. He added, if fuel has reaches a underground water vein, it will cause contamination of underground water, soil contamination and sea contamination. Moreover, if the underground water vein keeps being heated for long time, a massive hydrovolcanic explosion will be caused. He also warned radioactive debris is spreading in Pacific Ocean. Tons of the debris has reached the Marshall Islands as of 11/15/2011. –Fukushima Diary

http://theextinctionprotocol.wordpress.com/2011/11/21/architect-of-fukushimas-reactor-3-warns-of-massive-hydrovolcanic-explosion/

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TEPCO: Fukushima plant close to cold shutdown state

By TATSUYUKI KOBORI / Staff Writer http://ajw.asahi.com/article/0311disaster/fukushima/AJ201111180020

Tokyo Electric Power Co. said cold shutdown conditions have been achieved at the Fukushima No. 1 nuclear power plant, and is awaiting government confirmation on what would be a huge step toward ending the crisis.

However, nuclear experts continue to raise doubts that such conditions accurately reflect the state of the damaged reactors at the crippled nuclear plant.

TEPCO and government officials on Nov. 17 released a revised road map for bringing the situation at the Fukushima plant under control. The document said a state close to cold shutdown had been achieved since the reactor cores were being cooled stably and the amount of radioactive materials released into the outer environment had also decreased substantially.

The revised road map reiterated earlier objectives of achieving cold shutdown before the end of the year.

« Cooling is proceeding in a stable manner, » Goshi Hosono, the state minister in charge of the Fukushima nuclear accident, said. « We will carefully confirm over the next six weeks or so if this condition can be maintained. »

Officials of the Nuclear and Industrial Safety Agency are continuing their appraisal by hearing the opinions of experts, although they have informed their U.S. counterparts that a situation equivalent to cold shutdown had been achieved, sources said.

The final decision on whether cold shutdown has been reached will be up to Japan’s political leaders.

Through cooling of the No. 1 to No. 3 reactors that were hit by explosions and other accidents, the temperatures at the bottom of the pressure vessels were between 37 and 68 degrees, according to the document. Even if an error up to 20 degrees was included, the reactor temperatures still would be below 100 degrees, which is one of TEPCO’s conditions for a cold shutdown state.

The temperatures of gases within the containment vessel, into which some melted nuclear fuel is believed to have leaked, were also between 39 and 70 degrees, the document said.

The release of new radioactive materials was measured at levels of 60 million becquerels per hour at the gates to the Fukushima plant facility. That was lower than the provisional level of 100 million becquerels per hour detected about one month ago.

The level of additional radiation exposure caused by the nuclear accident was at a level of 0.1 millisievert over the course of a year, lower than the government standard of 1 millisievert, the document said.

But some nuclear experts have cast doubts on using the 100-degree temperature at the bottom of the pressure vessel as a condition for cold shutdown.

That temperature level is used for reactors operating under normal conditions. At the Fukushima plant, the control rods and nuclear fuel in the reactors have melted, and some may have leaked into the containment vessels.

Even at a meeting in October held by NISA officials, experts questioned the use of the temperature condition. Akira Yamaguchi, a professor of reactor core engineering at Osaka University, warned against focusing excessively on the 100-degree condition.

One reason the bottom of the pressure vessel is being used for the temperature condition is that it is relatively close to where the nuclear fuel is likely located. Moreover, few other locations are available where temperatures can be measured.

TEPCO officials can only estimate the temperatures of the fuel in the containment vessel because it is unclear where it is located.

Kazuhiko Kudo, a nuclear engineering professor at Kyushu University, said the situation at the Fukushima plant should not be described as cold shutdown. Instead, he said, a more accurate description would be a shutdown achieved through a complicated cooling system.

Normal cooling equipment was rendered inoperable by the March 11 quake and tsunami, forcing TEPCO to install temporary equipment connected by about 4 kilometers of hoses to cool the reactors.

When TEPCO first compiled the road map on April 17, there was no clear definition of what would constitute cold shutdown.

Soon thereafter, the central government and TEPCO finally acknowledged that meltdowns had occurred in the No. 1 to No. 3 reactors.

Other nuclear plants achieved cold shutdown at their reactors following the March 11 disaster. The focus on the three damaged reactors at the Fukushima No. 1 plant moved to when cold shutdown would be achieved rather than understanding the actual conditions of the reactors.

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More Radiation In Food In Japan

More Radiation In Food In Japan

http://www.simplyinfo.org/?p=4080

Japanese media announced yesterday that Fukushima rice that was previously declared “all safe” is now found to be not all safe. Harvest from farms around Fukushima City was found to be over the government limit of 500 bq/kg. The rice had not shipped. The government is now considering banning rice sales from Fukushima. This was almost expected when the government rushed to declare all Fukushima rice to be safe as they tested rice from areas far from the plant yet still in Fukushima prefecture. It smelled more like a publicity stunt than food testing and now has shown it was just that.

Grains in eastern Japan were tested by the  government. Wheat in Fukushima was found to be contaminated. Beef in Iwaki prefecture is showing with cesium contamination that is below the government limit.  The food situation in Japan is still tense. Some relief has been found as citizen groups and certain retailers do their own testing and bar the sale of items with contamination, even those well below the government limit.

 

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