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Air duct corrosion and holes found at seven nuclear plants

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Corrosion is seen in a ventilation duct at the No. 3 unit of the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture. | NUCLEAR REGULATION AUTHORITY
 
Corrosion and holes have been found in ventilation ducts at 12 reactors at seven nuclear plants across the country, the Nuclear Regulation Authority said Wednesday, raising concerns that workers could be exposed to radiation in the event of an accident.
The governmental nuclear watchdog released the results of a nationwide survey it had ordered following a revelation in December 2016 that corrosion had left multiple holes in the air ducts of the No. 2 reactor at Chugoku Electric Power Co.’s Shimane plant in western Japan. That reactor was not included in the survey.
Serious corrosion was found at the No. 3 unit of the Kashiwazaki-Kariwa plant in Niigata Prefecture operated by Tokyo Electric Power Company Holdings Inc. and may have abnormally affected ventilation of the central control room, the watchdog said.
Although the No. 7 unit at the same plant has passed a test to resume operation, the NRA said it will inspect the impact of any corrosion found at the reactor. No abnormality associated with corrosion has been found at the remaining 10 units, it said.
Corrosion or holes were found in steel or galvanized steel ducts at Tohoku Electric Power Co.’s Onagawa nuclear plant, Japan Atomic Power Co.’s Tokai No. 2 nuclear plant, Tepco’s Fukushima No. 1 nuclear plant and Kashiwazaki-Kariwa nuclear plant, Chubu Electric Power Co.’s Hamaoka plant, Hokuriku Electric Power Co.’s Shiga nuclear plant and Chugoku Electric’s Shimane plant.
If an accident occurs, radioactive materials could flow into a plant’s central control room through such holes, putting workers in danger of radiation exposure.
At the No. 3 reactor at the Kashiwazaki-Kariwa plant, a crack as large as 13 centimeters in length and 5 cm in width was found. A total of nine holes and cracks have been discovered at the Nos. 3 and 7 units at the plant.
All the reactors with corrosion were boiling-water reactors, the same type used at the Fukushima No. 1 plant, which spewed a massive amount of radioactive material into the atmosphere following the March 2011 earthquake and tsunami.
No problems have been detected at pressurized-water nuclear reactors, as filtering and other measures take place near air inlets.
The holes at the No. 2 unit at the Shimane plant were discovered when insulation materials covering the ducts were removed for inspection.
The holes, the largest of which measured about 100 centimeters wide and about 30 centimeters long, are believed to have been caused by dew condensation and rainwater that seeped inside the building, as well as salt deposits on the ducts, given that the corrosion extended about 50 meters from the air inlet and spread from the inner surface of the ducts.
Chugoku Electric has decided to increase the number of inspection points at sections near fresh-air inlets and bolster anti-corrosion measures, including the installation of a dehumidifier.
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May 24, 2018 Posted by | Japan | , , | Leave a comment

Fukushima Daiichi reactors internal estimates by Tepco

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In dismantling the Fukushima Daiichi nuclear power plant, it is essential to grasp the state of nuclear fuel melted its nuclear reactors, but the radiation is very high and it is difficult to see inside. Under these circumstances, TEPCO announced a new estimate chart for the interior of the three nuclear reactors.
TEPCO announced the estimate inside the nuclear reactors at the International Forum on Waste Plant on the July 3rd, 2017. In the inside of the nuclear reactor of Unit 3, a part of the nuclear fuel collapsed to the bottom of the pressure vessel and is stacked like a garbage while keeping its shape. Meanwhile, it seems that molten nuclear fuel has fallen to the bottom of the storage container beneath, but when analyzing the data at the time of the accident again, it is said that there is a possibility that it is eroding the concrete on the floor of the containment vessel .
Estimates were obtained reflecting computer simulations and recent internal surveys, etc. Based on these estimates, the government decided how to remove “fuel debris”.

https://headlines.yahoo.co.jp/videonews/nnn?a=20170703-00000081-nnn-soci

July 5, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Where to put all the radioactive waste is now the burning issue

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The call might have been made to decommission five over-the-hill nuclear reactors, but the problem remains of where to dispose of their total 26,820 tons of radioactive waste.

The plant operators have yet to find disposal sites, and few local governments are expected to volunteer to store the waste on their properties.

The decommissioning plans for the five reactors that first went into service more than 40 years ago was green-lighted by the Nuclear Regulation Authority on April 19.

It is the first NRA approval for decommissioning since the 2011 Fukushima nuclear disaster triggered by the Great East Japan earthquake and tsunami.

That disaster led to a new regulation putting a 40-year cap, in principle, on the operating life span of reactors.

The reactors to be decommissioned are the No. 1 reactor at Japan Atomic Power Co.’s Tsuruga plant in Fukui Prefecture; the No. 1 reactor at Kyushu Electric Power Co.’s Genkai plant in Saga Prefecture; the No. 1 and No. 2 reactors at Kansai Electric Power Co.’s Mihama plant in Fukui Prefecture; and the No. 1 reactor at Chugoku Electric Power Co.’s Shimane plant in Shimane Prefecture.

The decommissioning will be completed between fiscal 2039 and fiscal 2045 at a total cost of 178.9 billion yen ($1.64 billion), according to the utilities.

In the process, the projects are expected to produce 26,820 tons of radioactive waste–reactors and pipes included.

An additional 40,300 tons of waste, such as scrap construction material, will be handled as nonradioactive waste due to radiation doses deemed lower than the government safety limit.

Securing disposal sites for radioactive waste has proved a big headache for utilities.

About 110 tons of relatively high-level in potency radioactive waste, including control rods, are projected to pile up from the decommissioning of the No. 1 reactor at the Mihama plant.

Such waste needs to be buried underground deeper than 70 meters from the surface and managed for 100,000 years, according to the NRA’s guidelines.

In addition, the decommissioning of the same reactor will generate 2,230 tons of less toxic waste as well, including pipes and steam generators.

Under the current setup, utilities must secure disposal sites on their own.

Kansai Electric, the operator of the Mihama plant, has pledged to find a disposal site “by the time the decommissioning is completed.”

But Fukui Prefecture, which hosts that plant and others, is demanding the waste from the Mihama facility be disposed of outside its borders.

The project to dismantle the reactor and other facilities has been postponed at Japan Atomic Power’s Tokai plant in Ibaraki Prefecture because the company could not find a disposal site for the relatively high-level waste.

The decommissioning of the reactor had been under way there since before the Fukushima disaster.

The expected difficulty of securing disposal sites could jeopardize the decommissioning timetable, experts say.

Even finding a disposal site for waste that will be handled as nonradioactive has made little headway.

What is more daunting is the hunt for a place to store high-level radioactive waste that will be generated during the reprocessing of spent fuel, they said.

http://www.asahi.com/ajw/articles/AJ201704200039.html

April 20, 2017 Posted by | Japan | , , | Leave a comment

Japan to scrap 5 more nuclear reactors

String of facilities approaching maximum life span

0420N-Decommissioning-Business_article_main_image.jpgWorkers take apart a pump at Chubu Electric Power’s Hamaoka nuclear plant.

TOKYO — Five nuclear reactors in Japan were approved for decommissioning on Wednesday, pushing utilities and other companies to join hands to tackle both the great business opportunities and daunting technical problems involved with the process.

Two reactors at Kansai Electric Power‘s Mihama plant, as well as one each at Japan Atomic Power’s Tsuruga plant, Chugoku Electric Power‘s Shimane plant and Kyushu Electric Power‘s Genkai facility received the green light from Japan’s Nuclear Regulation Authority. The safety updates needed to keep them running beyond their mandated 40-year life span were deemed too costly.

Japan had 54 nuclear reactors before the 2011 meltdown at the Fukushima Daiichi nuclear plant. A total of 15, including the six at Fukushima Daiichi, are now set to be taken out of service. Another one or two will be brushing up against the 40-year limit every year, unless one-time, 20-year extensions are sought and granted.

Companies now face a pressing need to acquire expertise on dismantling reactors and disposing of radioactive materials. No commercial nuclear reactor has ever been decommissioned in Japan before, and utilities are looking for partners with the necessary capabilities.

Kansai Electric is seeking help from France’s Areva and Japan’s Mitsubishi Heavy Industries in decommissioning the Nos. 1 and 2 reactors at Mihama, particularly in decontaminating pipes and equipment. Japan Atomic Power and U.S.-based EnergySolutions signed an agreement last spring to cooperate on the former’s Tsuruga plant.

Japanese utilities are also beginning to work with each other. Kansai Electric entered a partnership last year with Kyushu Electric, Chugoku Electric and Shikoku Electric Power. The four plan to cut decommissioning costs by jointly procuring materials and sharing technology and staffers. 

Other players are also angling for a piece of the pie. Two years ago, Mitsubishi Heavy set up a department specializing in dismantling nuclear reactors. The company was a key player in building the Mihama and Genkai reactors, and wants a lead role in taking them apart. Japanese general contractor Shimizu also signed a technical cooperation agreement with U.K.-based Cavendish Nuclear.

Utilities have increased their rates in order to raise the necessary funds to decommission the five newly approved reactors. They have already come up with about 160 billion yen ($1.47 billion) of the estimated 180 billion yen total. But the process will likely take two or three decades, and costs could easily grow.

The utilities may also face significant challenges to disposing of the roughly 27,000 tons of contaminated waste the five reactors are expected to generate. For example, Japan Atomic Power wants to bury less radioactive materials at the site of the Tokai nuclear plant, one of the earlier plants approved for decommissioning, but faces strong local opposition.

Relevant legislation has not been finalized either. Highly contaminated materials are supposed to be buried more than 70 meters below ground. But the Nuclear Regulation Authority has only just begun debating exactly how they should be buried.

http://asia.nikkei.com/Politics-Economy/Policy-Politics/Japan-to-scrap-5-more-nuclear-reactors

April 20, 2017 Posted by | Japan | , | Leave a comment

5 Reactors Decommissioning Approved

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Decommissioning plans for 5 reactors approved

Japan’s nuclear regulator has approved plans submitted by operators of 4 power plants to decommission 5 aging nuclear reactors. The reactors are to be scrapped in a process lasting up to nearly 30 years.

The Nuclear Regulation Authority approved the plans at a meeting on Wednesday.

Under a government policy introduced after the 2011 nuclear accident at the Fukushima Daiichi plant, reactor lifespan was limited to 40 years in principle.

In 2015, utility companies decided to dismantle the 5 reactors. The 5 include 2 reactors at the Mihama plant and one at the Tsuruga plant, both in Fukui Prefecture, one at the Shimane plant in Shimane Prefecture and one at the Genkai plant in Saga Prefecture.

The plans call for first decontaminating pipes and dismantling facilities that are free of radioactive contamination.

The operators assume that the reactors and their buildings will be taken down and removed by fiscal 2045 at the latest.

At issue is where to put control rods, reactor parts and other radioactive waste. No site for a final disposal facility has been designated.

The regulator is checking another decommissioning plan for a reactor at the Ikata plant in Ehime Prefecture. The facility’s operator decided last year to dismantle it.

https://www3.nhk.or.jp/nhkworld/en/news/20170419_18/

 

Nuclear authority approves decommissioning plans for 5 aging reactors

TOKYO (Kyodo) — Japan’s nuclear authority approved decommissioning plans for five aging reactors at four power plants on Wednesday, the first such approvals since a government regulation was implemented after the 2011 Fukushima disaster to stop the operation of reactors beyond 40 years.

The five reactors are the Nos. 1 and 2 units at Kansai Electric Power Co.’s Mihama plant in Fukui Prefecture, the No. 1 unit at Japan Atomic Power Co.’s Tsuruga plant in Fukui Prefecture, the No. 1 unit at Chugoku Electric Power Co.’s Shimane plant in Shimane Prefecture and the No. 1 unit at Kyushu Electric Power Co.’s Genkai plant in Saga Prefecture.

While the utilities indicated it will take about 30 years to complete the decommissioning of each reactor, the disposal sites for the radioactive waste from the facilities have yet to be determined.

The decommissioning work will involve removing spent fuel from pools, dismantling reactors and demolishing surrounding facilities.

The regulation brought in following the 2011 disaster at Tokyo Electric Power Co.’s Fukushima Daiichi plant prohibits nuclear reactors from operating for over 40 years in principle, but the Nuclear Regulation Authority can approve the operation of a unit for up to 20 more years if the operator makes safety upgrades and the unit passes screening.

It was decided in March 2015 to scrap the five reactors, mainly due to profitability, as huge amounts of additional investment would be needed to meet the new safety requirements to keep the reactors operating beyond 40 years.

Meanwhile, the authority has given approval for the extended operation of the No. 3 unit at Kansai Electric’s Mihama plant as well as the Nos. 1 and 2 units at its Takahama plant in Fukui Prefecture, which are also around 40 years old.

The authority is currently examining Shikoku Electric Power Co.’s decommissioning plan for the No. 1 unit at the Ikata plant in Ehime Prefecture, after the utility decided in March 2016 to scrap the reactor.

In Wednesday’s meeting, the authority also decided that Japan Nuclear Fuel Ltd.’s uranium enrichment facility in the village of Rokkasho, Aomori Prefecture, satisfies regulatory requirements, virtually giving a green light for its operation. The decision will become official after consultation with the industry minister.

It will become the second fuel plant to clear new regulatory requirements after Global Nuclear Fuel-Japan Co.’s plant in Kanagawa Prefecture.

http://mainichi.jp/english/articles/20170419/p2g/00m/0dm/079000c

April 20, 2017 Posted by | Japan | , | Leave a comment

Nuclear Reactor Design Chosen – Not Because It Was Safe – But Because It Worked On Navy Submarines

From June 20, 2011

Virtually all of the nuclear reactors in the U.S. are of the same archaic design as those at Fukushima (Indeed, MSNBC notes that there are 23 U.S. reactors which are more or less identical to those at Fukushima.)

Called “light-water reactors”, this design was not chosen for safety reasons. Rather, it was chosen because it worked in Navy submarines.

Specifically, as the Atlantic reported in March:

In the early years of atomic power, as recounted by Alvin Weinberg, head of Oak Ridge National Laboratory in his book The First Nuclear Era, there was intense competition to come up with the cheapest, safest, best nuclear reactor design.

Every variable in building an immensely complex industrial plant was up for grabs: the nature of the radioactive fuel and other substances that form the reactor’s core, the safety systems, the containment buildings, the construction substances, and everything else that might go into building an immensely complex industrial plant. The light water reactor became the technological victor, but no one is quite sure whether that was a good idea.

Few of these alternatives were seriously investigated after light water reactors were selected for Navy submarines by Admiral Hyman Rickover. Once light water reactors gained government backing and the many advantages that conferred, other designs could not break into the market, even though commercial nuclear power wouldn’t explode for years after Rickover’s decision. “There were lots and lots of ideas floating around, and they essentially lost when light water came to dominate,” University of Strasbourg professor Robin Cowan told the Boston Globe in an excellent article on “technological lock-in” in the nuclear industry.

As it turned out, there were real political and corporate imperatives to commercialize nuclear power with whatever designs were already to hand. It was geopolitically useful for the United States to show they could offer civilian nuclear facilities to its allies and the companies who built the plants (mainly GE and Westinghouse) did not want to lose the competitive advantage they’d gained as the contractors on the Manhattan Project. Those companies stood to make much more money on nuclear plants than traditional fossil fuel-based plants, and they had less competitors. The invention and use of the atomic bomb weighed heavily on the minds of nuclear scientists. Widespread nuclear power was about the only thing that could redeem their role in the creation of the first weapon with which it was possible to destroy life on earth. In other words, the most powerful interest groups surrounding the nuclear question all wanted to settle on a power plant design and start building.

***

President Lyndon Johnson and his administration sent the message that we were going to use nuclear power, and it would be largely through the reactor designs that already existed, regardless of whether they had the best safety characteristics that could be imagined. [Nixon also fired the main government scientist developing safer types of reactors, because he was focused on safety instead of sticking with Nixon’s favored reactors.] We learned in later years that boiling water reactors like Fukushima are subject to certain types of failure under very unusual circumstances, but we probably would have discovered such problems if we’d explored the technical designs for longer before trying to start building large numbers of nuclear plants.

The Atomic Energy Commission’s first general manager – MIT professor Carroll Wilson – confirmed in 1979:

The pressurized water reactor was peculiarly suitable and necessary for a submarine power plant where limitations of space and wieght were extreme. So as interest in the civilian use of nuclear power began to grow, it was natural to consider a system that had already proven reliable in submarines. This was further encouraged by the fact that the Atomic Energy Commission provided funds to build the first civilian nuclear power plant … using essentially the same system as the submarine power plant. Thus it was that a pressurized light water system became the standard model for the world. Although other kinds of reactors were under development in different countries, there was a rapid scale-up of of the pressurized water reactor and a variant called the boiling water reactor developed by General Electric. These became the standard types for civilian power plants. in the United States and were licensed to be built in France, Germany, Japan and elsewhere.

If one had started to design a civilian electric power plant without the constraints of weight and space as required by the submarine, quite different criteria would apply.

(Wilson also notes that the engineers who built the original reactors didn’t really think about the waste or other basic parts of the plants’ life cycle.)

Ambrose Evans-Pritchard argues that there was another reason why all safer alternative designs – including thorium reactors – were abandoned:

The plans were shelved because thorium does not produce plutonium for bombs.

As Boing Boing notes:

Reactors like this [are] flawed in some ways that would be almost comical, were it not for the risk those flaws impart. Maybe you’ve wondered over the past couple of weeks why anyone would design a nuclear reactor that relied on external generators to power the pumps for it’s emergency cooling system. In a real emergency, isn’t there a decent chance that the backup generators would be compromised, as well?

It’s a good question. In fact, modern reactor designs have solved that very problem, by feeding water through the emergency cooling system using gravity, rather than powered pumps. Newer designs are much safer, and more reliable. But we haven’t built any of them in the United States …

Not the Navy’s Fault

This is in no way a criticism of the U.S. Navy or its submarine reactors. As a reader comments:

There are some things to know about Navy reactors:

  1. They don’t store thirty years worth of used, spent fuel rods next to the reactor.

  2. They don’t continue to operate a reactor that had a design life of 25 years for 60 years.

  3. The spent fuel pool is back on land on a base somewhere.

(In addition, the reactors on subs are much smaller than commercial reactors, and so have almost no consequences for the civilian population if they meltdown. And if an accident were to happen on a nuclear sub, the sub would likely sink or at least flood, presumably keeping the reactor from melting down in the first place.)

There Are No Independent Regulators and No Real Safety Standards

But at least the government compensates for the inherently unsafe design of these reactors by requiring high safety and maintenance standards.

Unfortunately, no …

As AP notes today:

Federal regulators have been working closely with the nuclear power industry to keep the nation’s aging reactors operating within safety standards by repeatedly weakening those standards or simply failing to enforce them.

***

Examples abound. When valves leaked, more leakage was allowed — up to 20 times the original limit. When rampant cracking caused radioactive leaks from steam generator tubing, an easier test of the tubes was devised so plants could meet standards.

***

Records show a recurring pattern: reactor parts or systems fall out of compliance with the rules; studies are conducted by the industry and government; and all agree that existing standards are “unnecessarily conservative.’’

Regulations are loosened, and the reactors are back in compliance.

Of course, the Nuclear Regulatory Commission – like all nuclear “agencies” worldwide – is 100% captured and not an independent agency, and the NRC has never denied a request for relicensing old, unsafe nuclear plants.

Indeed, Senator Sanders says that the NRC pressured the Department of Justice to sue the state of Vermont after the state and its people rejected relicensing of the Vermont Yankee plant, siding with the nuclear operator instead. The Nation notes:

Aileen Mioko Smith, director of Green Action Kyoto, met Fukushima plant and government officials in August 2010. “At the plant they seemed to dismiss our concerns about spent fuel pools,” said Mioko Smith. “At the prefecture, they were very worried but had no plan for how to deal with it.”

Remarkably, that is the norm—both in Japan and in the United States. Spent fuel pools at Fukushima are not equipped with backup water-circulation systems or backup generators for the water-circulation system they do have.

The exact same design flaw is in place at Vermont Yankee, a nuclear plant of the same GE design as the Fukushima reactors. At Fukushima each reactor has between 60 and 83 tons of spent fuel rods stored next to them. Vermont Yankee has a staggering 690 tons of spent fuel rods on site.

Nuclear safety activists in the United States have long known of these problems and have sought repeatedly to have them addressed. At least get backup generators for the pools, they implored. But at every turn the industry has pushed back, and the Nuclear Regulatory Commission (NRC) has consistently ruled in favor of plant owners over local communities.

After 9/11 the issue of spent fuel rods again had momentary traction. Numerous citizen groups petitioned and pressured the NRC for enhanced protections of the pools. But the NRC deemed “the possibility of a terrorist attack…speculative and simply too far removed from the natural or expected consequences of agency action.” So nothing was done—not even the provision of backup water-circulation systems or emergency power-generation systems.

As an example of how dangerous American nuclear reactors are, AP noted in a report Friday that 75 percent of all U.S. nuclear sites have leaked radioactive tritium.

Indeed, because of poor design, horrible safety practices, and no real regulation, a U.S. nuclear accident could be a lot worse than Fukushima.

http://www.washingtonsblog.com/2011/06/nuclear-reactor-design-chosen-not-because-it-was-safe-but-because-it-worked-on-navy-submarines.html

 

April 9, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Deadly nuclear radiation levels detected in Fukushima

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Extremely high radiation levels were detected using cameras and robots in tainted water inside a reactor containment vessel at the Fukushima No. 1 nuclear power plant, Japan Times reported Tuesday, citing Tokyo Electric Power Company Holdings Inc. (Tepco).

The latest readings, taken six years after the Fukushima nuclear meltdown, showed 11 sieverts per hour, according to Japan Times. It is the highest radiation level detected in water inside the containment vessel and is extremely dangerous. Sievert is a unit measurement for a dose of radiation. One sievert is enough to cause illness if absorbed all at once, and 8 sieverts will result in death despite treatment, according to PBS who relied on data from multiple sources including United States Nuclear Regulatory Commission and MIT’s Nuclear Science and Engineering department.

Following a major earthquake on March 11, 2011, a 15-metre tsunami disabled the power supply and cooling of three Fukushima reactors, causing a nuclear accident. Tepco, who operated the plant and has been tasked with cleaning up the worst nuclear incident, since the 1986 Chernobyl disaster in the former Soviet Union, has been some problems of late in its cleanup operation.

Recently, an exploratory robot malfunctioned and died after being sent inside reactor 2, in mid-February, due to exposure to “unimaginable” levels of radiation, close to 650 sieverts per hour. The previous highest recorded level was 73 sieverts per hour. Following the incident, Naohiro Masuda, president of Tepco’s Fukushima Daiichi Decommissioning project, told reporters the company had to rethink its methods in order to examine and extract the hazardous material stuck in the plant’s second reactor.

We should think out of the box so we can examine the bottom of the core and how melted fuel debris spread out,” Masuda said, according to the Japan Times.

Tepco has been attempting to locate melted fuel which leaked from the reactor’s pressure vessel and is believed to have settled at the bottom of the containment vessel that holds the contaminated water. So far, no such debris has been found, and Tepco decided to extend the survey by one day through Wednesday.

A robot sent by the company on March 20 reached the bottom but was unable to locate the melted fuel due to some pipes that blocked its view.  But it was able to take pictures of what appeared to be sand piling up near the pipes. The radiation readings near them were 6.3 sieverts per hour.

Judging from the radiation level, there is a high possibility that what is piling up on the pipes is not nuclear fuel,” a Tepco official said, according to the Asahi Shimbun

Cleaning up the plant may take an estimated 40 years and cost an estimated 21.5 trillion yen ($189 billion), according to the Guardian.

https://www.rawstory.com/2017/03/deadly-nuclear-radiation-levels-detected-in-fukushima/

March 23, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Lethal radiation levels but no melted fuel found in Fukushima reactor water

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The Unit 2 reactor building at Tokyo Electric Power Co.’s Fukushima Daiichi nuclear power plant.

The level of radiation was measured by a special robot on Sunday at a point about 30cm (one foot) from the bottom of the containment vessel of Reactor 1, the Japan Times reported on Tuesday.

The current radiation level is 11 sieverts per hour, the highest detected in water inside the containment vessel. A person exposed to this amount of radiation would likely die in about 40 minutes, the Japan Times reports.

Sunday’s probe also revealed sandy substances building up at the bottom of the vessel. Tokyo Electric Power Company Holdings (TEPCO) officials, however, dismissed the idea that it might be melted nuclear fuel.

Experts have been looking for the melted fuel, which they believe has been accumulating in tainted water.

In March 2011, a 9.1 earthquake and the 15-meter tsunami that followed disabled the cooling system of Fukushima’s three reactors, causing the worst nuclear incident since the 1986 Chernobyl incident in Ukraine.

TEPCO, which operates the crippled power plant, has been obliged to deal with the consequences of the incident.

In February, a robot sent to explore Reactor 2 broke down because of the “unimaginable” levels of radiation, close to 650 sieverts per hour. This was the first time a robot entered this reactor since the plant’s meltdown in 2011.

Previously, the highest radiation level was recorded one year after the disaster and went up to 73 sieverts per hour.

TEPCO has promised extract the hazardous material stuck in the plant’s second reactor, its president Naohiro Masuda said, according to the Japan Times.

In December, TEPCO nearly doubled the estimated cost for the Fukushima clean-up to $188 billion.

A zone of more than 300 square miles around the plant is currently uninhabitable due to the continuing radiation.

https://www.rt.com/news/381879-fukushima-reactor-radiation-lethal/

 

March 23, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Plan to tunnel under the reactor buildings to remove melted fuel

Buried in technical reports was this interesting plan. Researchers have developed a method to tunnel under the reactor buildings to remove melted fuel.

The plan itself bases itself in existing concepts for sealed underground tunnel systems similar to the BART train system in the US or the Channel in the UK. Japan has a similar tunnel system used for rail lines that run between the main island of Honshu and Hokkaido.

TEPCO has attempted to continue presenting a narrative that the melted fuel remained in the reactor vessels or at least remained in the containment vessels, making it more straightforward to remove. This new plan assumes fuel to have melted deeply down into the reactor building basement concrete or potentially through the ground below.

The plan doesn’t clarify how much human entry to the underground base unit would be allowed or required. Seeing broader planning for potential scenarios would seem a wise move after early work found unexpected surprises causing designers to go back and rework plans. For such a plan to be under development means there is some thought among the decommissioning research teams that a worst case scenario could exist. These would include further inspections inside the containment structures and horizontal drilling below the reactor buildings to obtain soil samples.

The divergence between the work of the parties that have to actually plan the decommissioning work vs. the parties that have a stake in comforting public relations is quite clear. The very notion of such a plan raises questions about the true nature of the meltdowns.

A complex system of drilling equipment, debris retrieval, and nuclear waste casks would be included in the system. Additional inspection work will be required to determine if this new method will be needed.

The same report also includes the controversial sarcophagus plan.

March 15, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Radiation levels in units 1 and 3 remain much higher than in unit 2, TEPCO unable to investigate conditions in there

As I wrote in my previous blog article, we cannot talk or know if there is an actual increase at this time, because it is the first measure they took at that place at this deep. To know if radiation is increasing we would need Tepco to make a 2nd measure at that place and that deep, and then to compare both measures. https://dunrenard.wordpress.com/2017/02/05/recently-found-fukushima-daiichis-reactor-2-high-level-of-radiation-does-not-mean-radiation-increase/

In Mali Martha Lightfoot’s own words: ” The measuring capacity is just getting better and they are reaching parts of the containment they were unable to monitor before. I think it’s important not to confuse more accurate readings with the misconception that they indicate that the levels are rising. It is shocking enough to get an indication of how high the levels still are. And we may find, as technology improves, that parts of the containment are higher still. But, that still does not indicate that the levels are rising, just that our ability to design monitoring devices is getting better. “

As Majia Nadesan is saying in her own blog article : “A separate article published in The Asahi Shimbun notes that radiation levels in units 1 and 3 remain so high (higher than unit 2) that TEPCO is unable to investigate conditions in there: If confirmed, the first images of melted nuclear fuel at the Fukushima No. 1 nuclear plant show that Tokyo Electric Power Co. will have a much more difficult time decommissioning the battered facility. The condition of what is believed to be melted fuel inside the No. 2 reactor at the plant appears far worse than previously thought. …High radiation levels have prevented workers from entering the No. 2 reactor, as well as the No. 1 and No. 3 reactors at the plant. MASANOBU HIGASHIYAMA (January 31, 2017) Images indicate bigger challenge for TEPCO at Fukushima plant. The Asahi Shimbun, http://www.asahi.com/ajw/articles/AJ201701310073.html

If radiation levels are at 530 sieverts an hour inside unit 2, I wonder what conditions are like in the 1 and 3 reactors, which are described as even hotter? I can tell you from watching the reactors on the webcams for 5 plus years that atmospheric emissions from unit 3 have never ceased (as illustrated below far right side of screenshot)”. http://majiasblog.blogspot.fr/2017/02/fukushima-daiichi-unit-2-measures-530.html

feb-2-2017-23-20

 

Anyway in the meantime those 3 reactors are still belly button opened up spitting high radiation into our skies and environment, the reactor 1 and 3 even higher radiation than reactor 2.

 

February 6, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Fukushima Daiichi Unit 2 Measures 530 Sieverts an hour but Units 1 and 3 Hotter Still

TEPCO is reporting measuring radiation levels of 530 SIEVERTS AN HOUR (10 will kill you dead pretty quickly) and has discovered a 2-meter hole in the grating beneath the reactor pressure vessel (1 meter-square hole found in grating):

Radiation level at Fukushima reactor highest since 2011 disaster; grating hole found. The Mainichi, February 2, 2017, http://mainichi.jp/english/articles/20170202/p2g/00m/0dm/087000c

TOKYO (Kyodo) — The radiation level inside the containment vessel of the No. 2 reactor at the crippled Fukushima Daiichi nuclear complex stood at 530 sieverts per hour at a maximum, the highest since the 2011 disaster, the plant operator said Thursday.

Tokyo Electric Power Company Holdings Inc. also announced that based on image analysis, a hole measuring 2 meters in diameter has been found on a metal grating beneath the pressure vessel inside the containment vessel and a portion of the grating was distorted.

…The hole could have been caused by nuclear fuel that penetrated the reactor vessel as it overheated and melted due to the loss of reactor cooling functions in the days after a powerful earthquake and tsunami on March 11, 2011 hit northeastern Japan.

According to the image analysis, about 1 square meter of the grating was missing.

…Images captured using a camera attached to a telescopic arm on Monday also showed part of the grating has gone. A further analysis of the images found a 2-meter hole in an area beyond the missing section on the structure.

A separate article published in The Asahi Shimbun notes that radiation levels in units 1 and 3 remain so high (higher than unit 2) that TEPCO is unable to investigate conditions in there:

MASANOBU HIGASHIYAMA (January 31, 2017) Images indicate bigger challenge for TEPCO at Fukushima plant. The Asahi Shimbun,http://www.asahi.com/ajw/articles/AJ201701310073.html

If confirmed, the first images of melted nuclear fuel at the Fukushima No. 1 nuclear plant show that Tokyo Electric Power Co. will have a much more difficult time decommissioning the battered facility.

The condition of what is believed to be melted fuel inside the No. 2 reactor at the plant appears far worse than previously thought.

…High radiation levels have prevented workers from entering the No. 2 reactor, as well as the No. 1 and No. 3 reactors at the plant.

If radiation levels are at 530 sieverts an hour inside unit 2, I wonder what conditions are like in the 1 and 3 reactors, which are described as even hotter?

I can tell you from watching the reactors on the webcams for 5 plus years that atmospheric emissions from unit 3 have never ceased (as illustrated below far right side of screenshot):

Feb 2, 2017 23:20
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http://majiasblog.blogspot.fr/2017/02/fukushima-daiichi-unit-2-measures-530.html

February 5, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Footage points to difficulty in removing possible melted fuel at Fukushima plant

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The footage released on Jan. 30 by Tokyo Electric Power Co. (TEPCO) showing what could be melted fuel inside the No. 2 reactor at the disaster-stricken Fukushima No. 1 Nuclear Power Plant has highlighted the difficulty of salvaging the object, which is apparently stuck to footholds and other equipment at the facility.
TEPCO took the footage as part of its in-house probe into the No. 2 reactor and found that black and brown sediments — possible melted fuel — are stuck inside the reactor’s containment vessel over an extensive area.

“If what was captured in the footage was melted fuel, that would provide a major step forward toward trying our hand at unprecedented decommissioning work,” said Yoshiyuki Ishizaki, head of TEPCO’s Fukushima Revitalization Headquarters, during a press conference in the city of Fukushima on Jan. 30. “The finding may provide a major clue to future work to retrieve the object,” he added.

At the time of the March 2011 meltdowns at the plant, there were 548 nuclear fuel rods totaling some 164 metric tons inside the No. 2 reactor, but they apparently melted down after the loss of power sources for the core cooling system, with part of the melted fuel penetrating through the pressure vessel before cooling down at the bottom of the containment vessel. The temperature of the reactor core topped 2,000 degrees Celsius at the time of the accident, melting metals including nuclear fuel inside the reactor.

The melted fuel has since come in contact with underground water flowing from the mountain side, generating radioactively contaminated water every day. In order to dismantle the reactor, it is necessary to take out the melted fuel, but high radiation levels inside the reactor had hampered work to locate the melted debris.

On Jan. 30, apart from the footage, TEPCO also released 11 pictures taken inside the No. 2 reactor. The images show the sediments in question stuck to metal grate footholds and water is dripping from the ceiling. Further analysis of those images may provide information on the current status of the disaster and positional clues to decommissioning work.

The in-house probe, however, has only focused on the No. 2 reactor, and there is no prospect of similar probes into the No. 1 and No. 3 reactors starting anytime soon as they were severely damaged by hydrogen explosions following the 2011 meltdowns.

In April 2015, TEPCO introduced a remote-controlled robot into the No. 1 reactor by way of a through hole in its containment vessel, but the device failed to locate melted fuel inside due to high radiation levels. While the utility is planning to send a different type of robot into the No. 1 reactor this coming spring, it would be difficult to carry out a survey similar to that conducted at the No. 2 reactor, as radiation levels are high around the through hole in the No. 1 reactor’s containment vessel, from which a device could access to right below the No. 1 reactor.

The No. 3 reactor, meanwhile, holds roughly 6.5-meter-deep contaminated water inside its containment vessel, a far larger volume than that accumulated at the No. 1 and No. 2 reactors. TEPCO has thus been developing a robot that can wade through water.

http://mainichi.jp/english/articles/20170131/p2a/00m/0na/007000c

 

January 31, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Japanese Flawed steel Components at the Center of French Nuclear Crisis – Major Questions & Implications for Japanese Reactors Safety

25 October 2016, Tokyo – The safety and regulation of the Japanese nuclear fleet is called into serious question by the discovery of Japanese-manufactured flawed steel components installed in operating French nuclear reactors forced to shut down last week by the French nuclear safety regulator ASN, according to a new Greenpeace report. The threat to nuclear reactor safety in Japan is due to the supply of steel components to the nuclear industry from both Japan Casting and Forging Company (JCFC) and the Japan Steel Works (JSW), according to the technical report (http://bit.ly/2eMqJMm) released today by Greenpeace Japan, by the nuclear engineering consultancy, Large&Associates of London. Evidence of astonishingly high levels of excess carbon far outside regulatory limits with the associated loss of steel toughness and significant increase in the risk of catastrophic failure of primary containment components, have been discovered in JCFC-manufactured components installed in steam generators in 12 reactors owned by the French state-utility, EdF. The independent French nuclear agency, IRSN, recently warned that due to the excess carbon content, there was an increased risk of failure of the affected steam generator leading to a potential reactor core meltdown.(1)

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These components are so fundamental to reactor safety, and consequences so potentially severe, that in every country with nuclear reactors across the planet, nuclear regulators require that these components must not have any possibility of failure under any operating circumstance over the lifetime of the reactor – so-called “break-preclusion” for the reactor safety case. For this reason the French regulator warned its worldwide counterparts, including the Nuclear Regulation Authority (NRA) in Japan, of the potential enormity of the situation should their nuclear power plants have similarly flawed components installed.

During the period 1994-2006, JCFC supplied flawed components to France, which somehow managed to pass through the quality assurance controls of JCFC, the supplier Areva, and the French regulator to be installed in operating reactors. How the defects were not detected along the supply chain has not yet been disclosed. A commissioner from the NRA is visiting France this week to discuss the crisis.

From 1984-1993, JCFC also supplied steam generator components to the following Japanese reactors: Takahama 3&4, Sendai 2, Tomari 1&2 and Tsuruga 2; JCFC steam generator and reactor pressure vessel components are installed in a total of 14 Japanese reactors (not including two reactors at Fukushima Daiini).

As a result of substandard manufacturing in Japan, citizens in France have been unknowingly exposed to the risk of catastrophic failure of critical reactor components which could result in a reactor core meltdown. Japanese-supplied steel is now at the center of France’s unprecedented nuclear crisis the scale of which has never been seen in any country. All 12 reactors supplied by JCFC are either in forced shutdown or about to be. It lacks all credibility that the Japanese nuclear industry would claim that there are no implications for the safety of their own nuclear reactors. The steel production records released in France did not reveal the scale of excess carbon, which was only found after physical testing. There are currently no plans for such tests in Japan. That is wholly unacceptable. There are many urgent questions that need to be answered by the industry and the NRA, and with full public disclosure and transparency,” said Shaun Burnie, senior nuclear specialist at Greenpeace Germany.

The French nuclear safety regulator has been investigating components supplied by both JCFC and the Japan Steel Works (JSW). Test results obtained by Greenpeace in June 2016 indicated that there was a possibility of excess carbon problem in JSW-manufactured components in the steam generator boiler pods – there are 3 or 4 steam generators in each pressurized water reactor PWR nuclear power plant, each weighs upwards of 300 to 400 tonnes and, typically, the cost of replacement is around US$130 to 150 million.

Since the French publication of the JCFC and JSW component test results, it has been claimed that JSW components are free of excess carbon. However, no tests results proving this have been disclosed and Large&Associates research raises questions over the credibility of this claim. The non destructive testing that has been conducted in France is incapable of identifying the scale of excess carbon. Large&Associatess recommends destructive testing as the only guaranteed method for proving carbon concentration.

The fact that French nuclear reactors have been operating with flawed Japanese-supplied critical components is astounding. This is an utter failure of both nuclear regulation and on the part of the Japanese steel suppliers to meet quality control requirements. The implications for Japan may be even greater, as JSW is also implicated in this scandal because it supplies the forged steel parts that make up the reactor pressure vessel, which is the very heart of both PWR and boiling water reactors (BWR) used in Japan. Every reactor in Japan has critical components from these two suppliers and they must all undergo non destructive testing, with the priority being the two reactors currently in operation, Ikata-3 and Sendai 2, which must be immediately shutdown and tested, in addition reactors slated for decommissioning must have their components destructively tested, ” said John Large, head of Large&Associates.

The Japanese utilities are required to submit documentation to the NRA by 31 October 2016 detailing the quality of the steel components supplied by Japanese companies, JCFC, JSW and the other steel supplier, JFE. This is however only a paper exercise and not the result of actual physical testing of components installed in reactors.

Greenpeace has today sent a copy of the Large&Associates report to the NRA. A series of urgent questions will be submitted, via a member of the Japanese Diet, to the NRA in the coming days.

Priority reactors to be assessed and tested in Japan due to their status: operating, possibility of early operation or approval by the NRA for restart are: Ikata 3, Sendai 2, Takahama 2, Takahama 3&4 (under appeal by Kansai Electric); and next in line for approval by NRA – Genkai 3&4 and  Kashiwazaki-kariwa 6&7.

Notes:
(1)  The Japanese supplied components under investigation in France are designated Class 1, by which they are not permitted under any circumstances to fail during operation due to the potentially severe consequences. Specifically the components are Steam Generator tube support plates, elliptical domes, and bottom channel heads; as well as Reactor Pressure Vessel upper and lower heads, rings and pressurizers. The French governments Institute for Radiological and Nuclear Safety (IRSN) warned in August that there was a risk of reactor fuel melt down if steam generators with excess carbon operated. A maximum carbon limit is set by regulation to prevent a reduction in the toughness of the steel in the steam generators and Reactor Pressure Vessel, reduced toughness can lead to thermal shock induced fast fracture, where the steel shatters like glass. See, IRSN, 2016 2016-00275 Objet: EDF – REP – Paliers CP0, CPY et N4 – Ségrégations en carbone des fonds primaires de générateurs de vapeur – Analyse de sûreté et mesures compensatoires, 5th August 2016.

Download the report

For further information:
Shaun Burnie, senior nuclear specialist, Greenpeace Germany (Tokyo): shaun.burnie@greenpeace.org, +81 (0)80 3694 2843

Kendra Ulrich, senior global nuclear campaigner, Greenpeace Japan: kendra.ulrich@greenpeace.org, +81 (0) 90 6478 5408

Chisato Jono, communications officer, Greenpeace Japan: chisato.jono@greenpeace.org, +81 (0)80-6558-4446

http://www.greenpeace.org/japan/ja/news/press/2016/pr201610251/

 

October 27, 2016 Posted by | Japan | , , , | Leave a comment

Five French nuclear reactors with Japan-made parts ordered to undergo safety tests ahead of schedule

Some Japanese reactors also used steel from JCFC, according to statements from the companies:

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France’s Nuclear Safety Authority has ordered the country’s EDF utility to conduct checkups at five nuclear reactors ahead of their scheduled maintenance tests, citing potential weakness in critical parts manufactured by a Japanese company, French media reported Tuesday.

All five nuclear reactors are using parts made by Kitakyushu-based Japan Casting & Forging Corp. (JCFC), which is now under scrutiny by Japan’s Nuclear Regulation Authority.

The NRA discussed the matter at its regular meeting on Wednesday as it has also found the company manufactured reactor pressure vessels in 13 Japanese nuclear reactors including the Sendai Nos. 1 and 2 reactors operated by Kyushu Electric Power Co. in Kagoshima Prefecture.

The Sendai No. 1 reactor is undergoing a regular checkup while the No. 2 reactor is in operation.

In addition, the NRA said JCFC had been manufacturing important components at the No. 2 unit at Kansai Electric Power Co.’s Mihama plant in Fukui Prefecture and No. 1 unit at Kyushu Electric Power Co.’s Genkai nuclear plant in Saga Prefecture, which have already been decommissioned.

The French nuclear watchdog ASN said earlier in June that parts manufactured by JCFC using a method called “forging,” in which metals are hammered and extended, contained a high carbon concentration that could lead to lower-than-expected mechanical strength.

In the documents submitted to the NRA meeting, JCFC admitted there is a possibility that the parts used in nuclear power plants in France contain carbon higher than the regulated limits, but parts used in Japan are manufactured after removing high-carbon concentration from steel.

According to the media reports, safety tests have already been carried out at seven of a total of 12 reactors in France that used parts manufactured by JCFC. Parts at four of the seven reactors are believed to contain a higher carbon concentration than permitted by standards.

Following these findings, ASN told EDF to test the remaining five reactors within three months.

France has 58 commercial nuclear reactors. At the No. 3 reactor at Flamanville nuclear plant, which is under construction, parts made in 2014 by Creusot Forge, a subsidiary of France’s Areva SA, were found to be lacking in strength. ASN later discovered that the parts manufactured by JCFC also had problems.

http://www.japantimes.co.jp/news/2016/10/19/national/five-french-nuclear-reactors-japan-made-parts-ordered-undergo-safety-tests/#.WAendSTKO-d

http://english.kyodonews.jp/news/2016/10/439407.html

Read also the related articles from September 3 & 5, 2016 :

https://dunrenard.wordpress.com/2016/09/03/steel-in-troubled-french-nuclear-reactor-used-in-13-japanese-reactors/

https://dunrenard.wordpress.com/2016/09/05/jcfc-steel-in-troubled-french-reactor-also-used-in-13-japanese-nuclear-power-plants/

 

October 19, 2016 Posted by | Japan | , , , , | Leave a comment

Public to get new $83-billion bill for Fukushima, reactor expenses

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The crippled Fukushima No. 1 nuclear power plant is located in the towns of Okuma and Futaba in Fukushima Prefecture.

The government plans to make the public pay an additional 8.3 trillion yen (about $83 billion) to decommission reactors at the crippled Fukushima nuclear plant and provide compensation for evacuees of the 2011 disaster, sources said.

The public’s money will also be used for the future decommissioning of reactors at other nuclear plants, they said on Sept. 20.

The burden will also affect families that switched from nuclear power generating utilities to new electric power companies after the liberalization of the electricity retail market for families in April this year.

Major utilities that operate nuclear plants are, in principle, required to secure funds through electricity charges to decommission their reactors. Tokyo Electric Power Co., operator of the stricken Fukushima No. 1 nuclear plant, is no exception.

Under the reforms of the power industry, the new electric power companies, which do not operate nuclear plants, were exempt from shouldering any burden related to nuclear power.

But the industry ministry wants to change that arrangement.

Even people in the ruling coalition and the government are criticizing the plan as an attempt to ease the burden of utilities that had long held regional monopolies.

The plan will damage the basic idea of the reforms,” said Taro Kono, former chairman of the National Public Safety Commission and a lawmaker of the ruling Liberal Democratic Party.

To realize the plan, the Ministry of Economy, Trade and Industry aims to submit revisions to the Electricity Business Law to the next year’s ordinary Diet session.

A government-approved organization is procuring funds from major electric power companies to assist in the eventual decommissioning of the reactors at the Fukushima No. 1 plant.

However, TEPCO has asked the government for additional support because more money will be needed for the lengthy operation.

The costs to decommission the reactors at the Fukushima plant are expected to soar to 6 trillion yen from the current estimate of 2 trillion yen, according to in-house documents of the industry ministry.

The ministry also needs an additional 3 trillion yen to cover compensation payments for evacuees from the 2011 nuclear disaster and 1.3 trillion yen to decommission reactors of other nuclear plants in the future, according to the documents.

To get the new electric power companies to pay part of the 8.3 trillion yen, the ministry plans to increase power grid “usage fees,” which are paid to major electric power companies.

It is necessary to collect costs from all of the people fairly,” said a high-ranking official of the ministry.

Some of the consumers switched to new electric power companies because they did not want to continue using electricity produced by nuclear power plants.

But the ministry official pointed out that those consumers had been using nuclear-generated electricity until March.

New electric power companies, which do not have their own power grids, have concluded contracts with only 2 percent of all households in Japan.

The ministry is concerned that if more families switch from nuclear plant operators to the new companies, it could become difficult to secure sufficient funds to cover reactor decommissioning costs.

Under the ministry’s plan, a standard family of three in areas covered by TEPCO will be required to pay an additional 180 yen every month. In areas covered by other major electric power companies, the corresponding figure will be about 60 yen.

http://www.asahi.com/ajw/articles/AJ201609210045.html

September 23, 2016 Posted by | Fukushima 2016 | , , , | Leave a comment