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Highly radioactive water leak at Fukushima No. 1 nuke plant

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In the background, from left, the No. 1, 2, 3, and 4 reactor buildings of the Fukushima No. 1 Nuclear Power Plant are seen, in Okuma, Fukushima Prefecture, on Oct. 31, 2016. In front are tanks used to store contaminated water.
Highly radioactive water has leaked from the disaster-crippled Fukushima No. 1 nuclear plant, Tokyo Electric Power Co. (TEPCO) announced on Aug. 17.
The estimated 50 milliliters of contaminated water remained inside the station dike, and there was no leakage to the outer environment, plant operator TEPCO said. An analysis found that the tainted water contained 22 million becquerels per liter of beta-ray-emitting radioactive materials.
According to the utility, a worker from a company cooperating with TEPCO spotted water dripping from multi-nuclide removal equipment at the facility at around 2:15 p.m. on Aug. 16. After the worker mended the part with tape, the leakage stopped.

 

August 19, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

AIPRI Reports on 257 Tons of Corium and 180 Million Curies of Deadly Heavy Metal Poison and Radiation Released From Fukushima

From December 2011, reposting it today so that people won’t think that the March 2011 Fukushima Daiichi nuclear disaster is behind us.

After 280 days of decaying, the 257 tons of lost corium from three of Fukushima’s reactors, which one assumes to have a burn rate of 14GWJ/t (14 kg fissioned per tonne), have produced a probable level of radioactivity of 180.37 million Curies, or 6.674E18 Becquerels (6673.6 PBq). […]

92.17% of this radioactivity is being emitted by fission products, and constitutes 28.07% of overall radiotoxicity. 7.83% of this radioactivity is made by activation products, and constitutes 71.93% of overall radiotoxicity. That is to say that here the radiotoxicity, which according to the eminently official ICRP’s dose factors equals 73.47 Billion potential lethal doses via inhalation and 15.53 Billion lethal doses via ingestion, results chiefly from the activation products, which by and large are alpha emitters.

On the other hand, the radioactivity in this case is produced primarily by fission products, which most often are beta (β− ) emitters. At the end of these 280 days of decaying, the radiation arises primarily from the following elements: Strontium 89 at 2.265%, Strontium 90 at 4.713%, Yttrium 90 at 4.713%, Yttrium 91 at 4.852%, …

…Yttrium 91 at 4.852%, Zirconium 95 at 8.067%, Ruthenium 106 at 9.297%, Caesium 134 at 4.737%, Cesium 137 at 6.209%, Barium 137 at 6.209%, Cerium 144 at 23.744%, Promethium 147 at 13.728%, Plutonium 241 at 5.505%, Cobalt 60 at 1.410%.

Consistent with the rate of decay of these 280 days, in 15 years the fuel will have lost 80.20% of its radioactivity, bringing it to 35.71 Curies – but its long-lived toxicity will be elevated by 13.35%, contrarily, to 83.28 Billion lethal doses. Without question, the overall radioactivity falls but the persistent radiotoxicity increases until 60 years or so later, it commences to decline ever-so slowly after 350 years! (This irrefutable augmentation of toxicity over time is largely due to the increase of Americium-241 – alpha – a daughter product far more toxic than its beta-emitting parent, Plutonium-241. Ultimately, it will take around 350 years for the radiotoxicity to return to its original level…”

 http://www.aipri.blogspot.co.uk/2011/12/la-radioactivite-des-3-corium-de.html

August 18, 2017 Posted by | Fukushima 2017 | , , | 1 Comment

High-priced Fukushima ice wall nears completion, but effectiveness doubtful

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A subterranean ice wall surrounding the nuclear reactors at the stricken Fukushima No. 1 Nuclear Power Plant to block groundwater from flowing in and out of the plant buildings has approached completion.

Initially, the ice wall was lauded as a trump card in controlling radioactively contaminated water at the plant in Fukushima Prefecture, which was crippled by meltdowns in the wake of the March 2011 Great East Japan Earthquake and tsunami. But while 34.5 billion yen from government coffers has already been invested in the wall, doubts remain about its effectiveness. Meanwhile, the issue of water contamination looms over decommissioning work.

In a news conference at the end of July, Naohiro Masuda, president and chief decommissioning officer of Fukushima Daiichi Decontamination & Decommissioning Engineering Co., stated, “We feel that the ice wall is becoming quite effective.” However, he had no articulate answer when pressed for concrete details, stating, “I can’t say how effective.”

The ice wall is created by circulating a coolant with a temperature of minus 30 degrees Celsius through 1,568 pipes that extend to a depth of 30 meters below the surface around the plant’s reactors. The soil around the pipes freezes to form a wall, which is supposed to stop groundwater from flowing into the reactor buildings where it becomes contaminated. A total of 260,000 people have worked on creating the wall.

ice wall 16 august 2017 2.jpgThis photo shows pipes to freeze soil for the ice wall next to the No. 4 reactor at TEPCO’s Fukushima No. 1 Nuclear Power Plant, in Okuma, Fukushima Prefecture, on June 1, 2016. (Mainichi)

 

The plant’s operator, Tokyo Electric Power Co. (TEPCO) began freezing soil in March last year, and as of Aug. 15, at least 99 percent of the wall had been completed, leaving just a 7-meter section to be frozen.

Soon after the outbreak of the nuclear disaster, about 400 tons of contaminated water was being produced each day. That figure has now dropped to roughly 130 tons. This is largely due to the introduction of a subdrain system in which water is drawn from about 40 wells around the reactor buildings. As for the ice wall, TEPCO has not provided any concrete information on its effectiveness. An official of the Secretariat of the Nuclear Regulation Authority (NRA) commented, “The subdrain performs the primary role, and the ice wall will probably be effective enough to supplement that.” This indicates that officials have largely backtracked from their designation of the ice wall as an effective means of battling contaminated water, and suggests there is unlikely to be a dramatic decrease in the amount of decontaminated groundwater once the ice wall is fully operational.

TEPCO ordered construction of the ice wall in May 2013 as one of several plans proposed by major construction firms that was selected by the government’s Committee on Countermeasures for Contaminated Water Treatment. In autumn of that year Tokyo was bidding to host the 2020 Olympic and Paralympic Games, and the government sought to come to the fore and underscore its measures to deal with contaminated water on the global stage.

Using taxpayers’ money to cover an incident at a private company raised the possibility of a public backlash. But one official connected with the Committee on Countermeasures for Contaminated Water Treatment commented, “It was accepted that public funds could be spent if those funds were for the ice wall, which was a challenging project that had not been undertaken before.” Small-scale ice walls had been created in the past, but the scale of this one — extending 1.5 kilometers and taking years to complete — was unprecedented.

At first, the government and TEPCO explained that an ice wall could be created more quickly than a wall of clay and other barriers, and that if anything went wrong, the wall could be melted, returning the soil to its original state. However, fears emerged that if the level of groundwater around the reactor buildings drops as a result of the ice wall blocking the groundwater, then tainted water inside the reactor buildings could end up at a higher level, causing it to leak outside the building. Officials decided to freeze the soil in stages to measure the effects and effectiveness of the ice wall. As a result, full-scale operation of the wall — originally slated for fiscal 2015 — has been significantly delayed.

ice wall 16 august 2017.jpgA worker makes checks with a hammer on an impermeable wall near TEPCO’s No. 4 reactor in the town of Okuma in Fukushima Prefecture on Feb. 24, 2017. (Mainichi)

 

Furthermore, during screening by the NRA, which had approved the project, experts raised doubts about how effective the ice wall would be in blocking groundwater. The ironic reason for approving its full-scale operation, in the words of NRA acting head Toyoshi Fuketa, was that, “It has not been effective in blocking water, so we can go ahead with freezing with peace of mind” — without worrying that the level of groundwater surrounding the reactor buildings will increase, causing the contaminated water inside to flow out.

Maintaining the ice wall will cost over a billion yen a year, and the radiation exposure of workers involved in its maintenance is high. Meanwhile, there are no immediate prospects of being able to repair the basement damage in the reactor buildings at the crippled nuclear plant.

Nagoya University professor emeritus Akira Asaoka commented, “The way things stand, we’ll have to keep maintaining an ice wall that isn’t very effective. We should consider a different type of wall.”

In the meantime, TEPCO continues to be plagued over what to do with treated water at the plant. Tainted water is treated using TEPCO’s multi-nuclide removal equipment to remove 62 types of radioactive substances, but in principle, tritium cannot be removed during this process. Tritium is produced in nature through cosmic rays, and nuclear facilities around the world release it into the sea. The NRA takes the view that there is no problem with releasing treated water into the sea, but there is strong resistance to such a move, mainly from local fishing workers who are concerned about consumer fears that could damage their businesses. TEPCO has built tanks on the grounds of the Fukushima No. 1 plant to hold treated water, and the amount they hold is approaching 800,000 metric tons.

In mid-July, TEPCO Chairman Takashi Kawamura said in an interview with several news organizations that a decision to release the treated water into the sea had “already been made.” A Kyodo News report on his comment stirred a backlash from members of the fishing industry. TEPCO responded with an explanation that the chairman was not stating a course of action, but was merely agreeing with the view of the NRA that there were no problems scientifically with releasing the treated water. However, the anger from his comment has not subsided.

Critical opinions emerged in a subsequent meeting that the Ministry of Economy, Trade and Industry held in the Fukushima Prefecture city of Iwaki at the end of July regarding the decontamination of reactors and the handling of contaminated water. It was pointed out that prefectural residents had united to combat consumer fears and that they wanted officials to act with care. One participant asked whether the TEPCO chairman really knew about Fukushima.

The ministry has been considering ways to handle the treated water, setting up a committee in November last year that includes experts on risk evaluation and sociology. As of Aug. 15, five meetings had been held, but officials have yet to converge on a single opinion. “It’s not that easy for us to say, ‘Please let us release it.’ It will probably take some time to reach a conclusion,” a government official commented.

https://mainichi.jp/english/articles/20170816/p2a/00m/0na/016000c

 

August 17, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Japanese Nuclear Regulator Permits Completion of ‘Ice Wall’ Beneath Fukushima

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Japan’s Nuclear Regulation Authority has approved the completion of the remaining parts of the Fukushima nuclear power plant’s “ice wall” ground freeze beneath the station in order to prevent groundwater from entering the damaged reactor’s facilities, local media reported Tuesday.

MOSCOW (Sputnik) – The plan stipulates creating a 0.9 mile long barrier by circulating coolant of 30 degrees below zero in pipes buried around the building. The “ice wall” is expected to keep groundwater from entering the station and therefore prevent an increase in amounts of water contaminated by radioactive substances. Initially, the Nuclear Regulation Authority was concerned with the fact that if the whole wall was created, it would probably lead to a drastic decrease in water in the area around the station and cause leakages of contaminated water outside the damaged reactor’s building. Experts thus previously ruled to leave a 23-foot section of the wall unfrozen.

According to the NHK broadcaster, the Tokyo Electric Power Company (TEPCO), responsible for the project, claimed that the completion of the wall would not result in a sudden decrease of water levels, and even if it would, the company promised to take immediate measures. After considering the company’s position, experts allowed to complete the “ice wall.”

The broadcaster said that TEPCO will begin the remaining work on August 22, completing the soil freeze that first began in March 2016. It was also reported that after the works are completed, the Nuclear Regulation Authority would carefully assess the results and examine whether there have been any positive improvements in water contamination.

In 2011, a major earthquake triggered a tsunami that hit Japan’s Fukushima NPP and led to the leakage of radioactive materials and the shutdown of the plant. Following the incident, Tokyo shut down all the NPPs in Japan and began to restart them after introducing new security standards.

https://sputniknews.com/asia/201708151056482387-japan-fukushima-ice-wall/

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August 17, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Fukushima nuke plant decommissioning still has long way to go

 

Mainichi Shimbun reporters visited the Fukushima No. 1 Nuclear Power Plant on July 27. While the working environment at the station has improved, plant operator Tokyo Electric Power Co. (TEPCO) still has a mountain of problems to tackle, such as removing melted nuclear fuel from the No. 1 to No. 3 reactors and treating contaminated water.

https://mainichi.jp/english/articles/20170811/p2a/00m/0na/025000c

August 14, 2017 Posted by | Fukushima 2017 | , | Leave a comment

The comic strip journalist who reports on the fallout from Fukushima

On the eve of his appearance at a Victoria University event in Wellington, comic book author Fumio Obata talks to Guy Somerset about his ongoing project chronicling the aftermath of the Fukushima tsunami and nuclear disaster.

At art school, Fumio Obata was taught the importance of “the theme, having something of your own, something only you can do”. The theme that has preoccupied Obata for the past five years is one he has truly made his own. He has been chronicling, through striking comic book reportage, the devastating consequences of the magnitude 9.1 earthquake that struck off the northeast Pacific coast of Japan in March 2011, causing a tsunami and meltdowns and radioactive contamination at the Fukushima Daiichi nuclear plant.

Published in Italian magazine Internazionale and on his website, Obata’s comic strips capture the long-term effects of Fukushima and explore some of the knotty social, political and environmental issues raised by the disaster and its aftermath. The strips are destined to become his second book, his first being 2014’s internationally successful graphic novel Just So Happens, for which The Observer reviewer Rachel Cooke praised his “crazily accomplished” storytelling and described him as “a talent to watch”.

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Reviews like that – and there were plenty more where it came from – can bring a writer a lot of opportunities and Obata was no exception, but he laughs: “I haven’t used them very well. Terrible, isn’t it? The good guys who had their debuts the same time as me, they are already on to their third or fourth book. Whereas me, I’m just caught up in this massive theme. Strategy-wise, I’m not very good!”

Obata is at Victoria University of Wellington this week as a visiting scholar in its School of Design. While he’s there, he’s taking part in a four-day international symposium on cultural sustainability, including a free public event with fellow writers Australian Ellen van Neerven and New Zealander Pip Adam.

His trip from the UK, where he has lived since 1991, when his Anglophile parents sent him to boarding school there from Japan, was broken with a stop-off in Tokyo and more reporting from the region around Fukushima, where 19,416 people died as a result of the 2011 earthquake and tsunami. There are still 2553 people listed as missing and 123,000 evacuees scattered around the country.

A YouTube video on Obata’s website gives a sense of what such reporting can entail. In it, dressed in a white protective suit, he walks through an eerily desolate ghost town that is about two kilometres from Fukushima and part of the designated exclusion zone.

 

If you become friends with a resident, they have a pass and you can go there with them,” he says. He and his friend wore protective suits, but clear-up and other workers don’t. “They don’t become ill. They say it is fine. Even in the exclusion zone, it’s not all equally radioactive. Because particles are not going to be evenly dispersed. When you walk around with the Geiger counter, you notice that sometimes the figure is very low, then you go several feet away from that spot and the figure jumps up. Even outside the exclusion zone, if you go to the bits closest to the zone you find the figures are very high.”

Obata’s reporting, which he describes as “a kind of journalism, but I’m more doing my philosophical take on it”, begins with him taking photographs and recording interviews.

Because I’m trying to structure a narrative, usually it’s the words I start with. I listen to the interviews I did and write down as much as I can. Then I take out the key words, the phrases I think are important, simplifying it. It’s very important simplifying the information. Because what I’m making is a comic strip. It’s not an article, which allows you to have I don’t know how many words: 2000, 3000. I need the space for pictures so I can’t have 3000 words.

After that, I look at the photographs. Again, I may have about 200 photographs. I have to go through them and use about 10 out of 200. Those photographs are going to be my visual sources. Then I start sketching. All those sketches and rough pictures, they are like pieces of the puzzle. I’ve got a dozen pieces of puzzle with words and phrases and I’ve got the other side of the puzzle with the photographs, and I basically put them together.”

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One of the most affecting stories Obata tells is that of Norio Kimura, whose father, wife and seven-year-old youngest daughter Yūna were lost in the tsunami. While the bodies of his father and wife were found in April 2011, Yūna’s remained missing. After the official search for her ended, Kimura continued looking, taking 1000km round trips to do so. After five years and nine months, a piece of bone was discovered that DNA testing proved was one of Yūna’s.

Yūna was torn apart into small pieces, taken away with contaminated debris, now stored around anonymously,” reads one of the story’s panels. “Had they done the search longer and more carefully from the start, she could have been found a lot earlier, with her body almost intact too.”

The story ends with a panel reading: “A child has been left out alone in the shadow of the reconstruction. And her presence now poses a lot of questions to us.”

This is emotionally momentous material, very different to some of Obata’s other work, be it his 2004 anime of Duran Duran’s song Careless Memories for their then stage show or the short comic about the art of pencil sharpening you’ll find on his website.

Getting it right must weigh upon him, one imagines: these are hugely significant events and he’s almost certainly the only person who’s going to approach them in this form.

Yeah, big pressure,” he says. “It’s very difficult to do. I appreciate people allow me to talk to them. Some say no, of course. I’ve heard tragic stories but they’ve asked me not to write about it. It’s interesting because they wanted to share that with somebody, somebody who’s not shared the same experience they have.

The father I met is very vocal because he’s angry. He’s just full of anger. He’s trying to change something about the law, for the love of his daughter. It’s very moving. That’s why he basically opened up to me. His story is still developing and he’s still searching for the remains of his daughter.”

Another panel in the same story is of a city skyline at night and reads: “The nuclear plant was built to provide electricity to the capital region. By knowing Fukushima today, Tokyo could look arrogant, with all the excess of lights and luxury.”

It’s a point elegantly distilled – even poetically so.

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But Obata is not one to cast simplistic blame. “It is something I have to tell people, especially my students [at the University of Gloucester and other universities around the UK where he teaches as a guest lecturer] when they try to do something about the world. They are angry young men, angry young people, but there are layers to things. There’s no right or wrong; the people are goodies and the people are baddies as well.

When a tragedy happens, we tend to think there’s a victim and there’s an offender. There’s going to be people who get accused and there are victims who get all the sympathy from the public. But sometimes it’s not like that. Sometimes you can’t make things black and white.

What’s happening with nuclear is one of these things. If you start reading just a short history of the nuclear industry, or nuclear technology, you see a lot of people believe in the technology and I can’t blame them, because I can’t prove them wrong. They get accused and the people who accuse them have right things to say and I can’t blame them either.

So basically there are no answers to it and it’s very uncomfortable for the human mind not to have answers. You need a bit of patience and courage to accept that. This is one of the things I am going to say at the end, I think: it’s difficult to accept an open ending but you’ve got to have the courage.”

As for Tokyo: “The consumption of energy really helped to establish today’s Japan’s reputation. And I’m part of it. I can’t really criticise it. I just have to take in the contradiction and try to respond.”

Responding to this and the other contradictions he’s encountered in the past five years still has a way to run for Obata. Asked if he’s going to make the 2018 publication date his website gives for his book, he laughs: “Nah, of course not. I just have to put a lot of energy into it and hope the pictures can deliver the intensity of what I’ve seen.”

https://thespinoff.co.nz/media/09-08-2017/the-comic-strip-journalist-who-reports-on-the-fallout-from-fukushima/

 

August 14, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

1,700 Contaminated Vehicles Removed from Fukushima Daiichi Plant Site

Excessive radiation detected in vehicles removed from Fukushima nuke plant

Some of the cars were sold on the used-car market while two others remain unaccounted for, according to plant operator Tokyo Electric Power Co.

Radiation topping the government-set limit has been detected in about 190 vehicles removed from the premises of the Fukushima No. 1 Nuclear Power Plant after the outbreak of the nuclear crisis, it has been learned.

Some of the cars were sold on the used-car market while two others remain unaccounted for, according to plant operator Tokyo Electric Power Co. (TEPCO).

Approximately 1,700 vehicles were parked on the premises of the power station when the nuclear crisis broke out after it was hit by the powerful earthquake and tsunami on March 11, 2011, TEPCO officials said. Of those, about 600 were owned by employees of TEPCO or companies contracted by the utility. Over a 12-day period until radiation screenings began on March 23 of that year, people could drive the vehicles out of the premises of the plant without checks.

The Economy, Trade and Industry Ministry instructed TEPCO in February 2012 to conduct a follow-up probe into the use of these vehicles for fear that next owners of those cars could be exposed to radiation without knowing that the vehicles were contaminated.

The power company conducted a survey on employees and contracted companies that parked their cars on the plant’s premises at the time of the accident, and confirmed that about 460 vehicles were brought out of the plant by April 2015. It was learned that radiation levels for around 190 of the vehicles exceeded government-set safety standards, and some of them were found contaminated with radiation nearly 10 times over the limit. All the vehicles whose radiation levels exceeded the limit were collected from their owners and are now stored on TEPCO’s premises situated in a Fukushima Prefecture area designated as a highly contaminated “difficult-to-return zone.”

TEPCO is considering how to dispose of these heavily contaminated vehicles, with an official saying, “We’d like to continue searching for two vehicles that remain unaccounted for and respond to the situation in an appropriate manner.”

http://mainichi.jp/english/articles/20170809/p2a/00m/0na/013000c

Tainted cars left Fukushima compound unchecked

The operator of the Fukushima Daiichi nuclear power plant says hundreds of vehicles contaminated with radioactive substances left the compound unchecked in the immediate aftermath of the 2011 accident.
Tokyo Electric Power Company says that in 2012 it began investigating what had happened to privately owned vehicles at the plant, and found that about 460 had left the compound.
TEPCO officials located most of them by 2015. About 190 registered radiation levels that were higher than the government standards. They managed to track down all 190, but some of them had been sold to new owners.
Some of the cars were so contaminated that the radiation couldn’t be measured by equipment capable of detecting levels nearly 10 times greater than the official limits.
Two vehicles remain unaccounted for.
TEPCO says it did not conduct radiation checks of cars leaving the compound for 12 days after the accident started on March 11th, 2011.
The company has apologized for causing concern and says it will keep trying to locate the 2 vehicles.

https://www3.nhk.or.jp/nhkworld/en/news/20170809_01/

August 10, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Tritium in Us All

From Majia ‘s Blog:

Life on earth is becoming “tritiated” as the stable hydrogen in our water is replaced by an unstable isotope of hydrogen called Tritium:

Biello, David. (2014, February 7). Is Radioactive Hydrogen in Drinking Water a Cancer Threat? The EPA plans to reevaluate standards for tritium in water. Scientific American,

http://www.scientificamerican.com/article/is-radioactive-hydrogen-in-drinking-water-a-cancer-threat/

Such leaks have prompted the EPA to announce on February 4 plans to revisit standards for tritium that has found its way into water—so-called tritiated water, or HTO—along with risk limits for individual exposure to radiation and nuclear waste storage, among other issues surrounding nuclear power.

The agency’s recent announcement in the Federal Register notes that tritium levels as high as 3.2 million picocuries per liter (pCi/L) in ground water have been reported to the U.S. Nuclear Regulatory Commission (NRC) at some nuclear facilities. (A curie is a unit of radiation emission; a picocurie is one trillionth of a curie.) That is 160 times higher than the standard set back in 1977 by the fledgling EPA—and the NRC has made measurements even higher at some nuclear facilities. “Because of these releases to groundwater at these sites, and related investigations, the agency considers it prudent to reexamine its initial assumption in 1977 that the water pathway is not a pathway of concern,” the EPA stated in its filing.

Tritium bioaccumulates in phytoplankton (which is composed of algae, protists and cyanobacteria) and has been consequently evaluated as posing a persistent and toxic contaminant with intergenerational effects. See the following source:

Jaeschke, B. C., & Bradshaw, C. (2013). Bioaccumulation of tritiated water in phytoplankton and trophic transfer of organically bound tritium to the blue mussel, mytilus edulis. Journal of Environmental Radioactivity, 115, 28-33. 

TEPCO is going to dump into the ocean 770,000 tons or so of highly tritiated water stored at Fukushima because the site has reached storage limits and yet still cannot filter tritium, among other elusive radionuclides, contaminating the 400 tons or so of radioactive water that is produced anew at the site every single day. 

Tepco has been struggling to de-contaminating the water it captures from injections and ground water influx. A wastewater treatment facility was built early in the disaster, but the various decontamination systems implemented have been unable to eliminate all radionuclides, especially tritium.[i] 

In 2013, TEPCO reported that filtered water measured 710 million Becquerels per liter while unfiltered water was reported as twice as radioactive.[ii] Tritium was believed to the major source of residual contamination in the filtered water.[iii] The filtration system has also accidentally dumped unfiltered water, contaminated with Cesium-134, Cesium-137, and Iodine-131, into the sea.[iv]

TEPCO admits it cannot manage the tritiated water stored at the site. No one talks at all about the tritiated fog produced every single night at Fukushima Daiichi:

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Japan and US nuclear “authorities” are saying there is no alternative to dumping tritiated water in the ocean:

Nagata, Kazuaki (2015, March 31) Ex-U.S. nuclear chief says tritium water at Fukushima No. 1 can be dumped safely. Japan Times, http://www.japantimes.co.jp/news/2015/03/31/national/former-u-s-nuclear-chief-says-tritium-water-at-fukushima-no-1-can-safely-be-dumped-in-sea/#.VRqyleHWyDk

A former chief U.S. nuclear regulator asserted Tuesday that the massive volumes of tritium-tainted water stored at the Fukushima No. 1 nuclear plant can be “safely” dumped into the sea after it is diluted to reduce the levels of radioactive tritium below the legal limit….   Tepco has said the level of tritium in the water is between 1 million and 5 million becquerels per liter. The legal limit for release to the sea is 60,000 becquerels.

Tritium has a half life of 12.3 years, so it would take decades to die down to permitted levels if left undiluted. The element is about one-thousandth as radioactive as the isotopes cesium-134 and cesium-137, according to Tepco.

TEPCO may have to dump because the tritiated water isn’t simply taking up space. Its also producing Bremsstrahlung Radiation. https://en.wikipedia.org/wiki/Bremsstrahlung

Here is what the US Dept. of Health and Human Services has to say about this type of electro-magnetic radiation, which according to nuclear engineer Arnie Gundersen, among others, is being produced in Fukushima’s water tanks (see here http://podcast.gcnlive.com/podcast/power_hr/0116143.mp3:

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service Agency for Toxic Substances and Disease Registry (1999, September). TOXICOLOGICAL PROFILE FOR IONIZING RADIATION U.S. Division of Toxicology/Toxicology Information Branch 1600 Clifton Road NE, E-29 Atlanta, Georgia 30333 

Gamma radiation and x rays are types of electromagnetic radiations that behave identically but differ in their origin; gamma emissions originate in the nucleus while x rays originate in the orbital electron structure, or from the slowing down or stopping of highly energetic beta particles or electrons. The x rays that originate in the orbital structure are called characteristic x rays, and are useful in chemical analysis while those due to stopping high speed electrons are called bremsstrahlung. Page 41. 

GLOSSARY P. 337: Bremsstrahlung—Electromagnetic radiation (photons) produced by the acceleration that a fast charged particle (usually an electron) undergoes from the effect of an electric or magnetic field, for instance, from the field of another charged particle (usually a nucleus). Bremsstrahlung is emitted when beta particles or electrons are stopped by a shield.

Tritium is a beta emitter. The highly tritiated water stored at Fukushima Daiichi is decaying high energy electrons, or beta particles, whose interactions with shielding is producing a form of X-rays known as “breaking radiation” when translated from the German Bremsstrahlung.

The ocean and the atmosphere are becoming increasingly tritiated. Tritium was rare on earth before the atomic age according to Wikipedia, although found in the upper atmosphere.

What does it mean for the earth’s lower atmosphere and hydrology to become tritiated?

Tritium is entering the earth’s hydrological cycle according to this report by Canada’s Nuclear Regulator:

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Source: Minister of Public Works and Government Services Canada (2009, December). Investigation of the Environmental Fate of Tritium in the Atmosphere: Part of the Tritium Studies Project INFO-0792. Canadian Nuclear Safety Commission (CNSC). ISBN 978-1-100-13928-9

LET US LEARN ABOUT TRITIUM FROM THE US Environmental Protection Agency http://www.epa.gov/radiation/radionuclides/tritium.html

How are people exposed to tritium?

People are exposed to small amounts of tritium every day, since it is widely dispersed in the environment and in the food chain. People who live near or work in federal weapons facilities or nuclear fuel cycle facilities may have increased exposure. People working in research laboratories may also come in contact with tritium.

How does tritium get into the body?

Tritium primarily enters the body when people swallow tritiated water. People may also inhale tritium as a gas in the air, and absorb it through their skin.

What does tritium do once it gets into the body?

Tritium is almost always found as water, or “tritiated” water. Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the body. Tritium is excreted through the urine within a month or so after ingestion. Organically bound tritium (tritium that is incorporated in organic compounds) can remain in the body for a longer period.

Tritium atoms can exchange with any hydrogen atoms. If the hydrogen atom is part of an organic molecule, the tritium becomes ‘organically bound’ and is transported with the molecule rather than moving freely like water.

 

Health Effects of Tritium

 

As with all ionizing radiation, exposure to tritium increases the risk of developing cancer. However, because it emits very low energy radiation and leaves the body relatively quickly, for a given amount of activity ingested, tritium is one of the least dangerous radionuclides. Since tritium is almost always found as water, it goes directly into soft tissues and organs. The associated dose to these tissues are generally uniform and dependent on the tissues’ water content.

Tritium in us all….

RESOURCES

[i] Yoshida ‘Fukushima No. 1 Can’t Keep its Head Above Tainted Water.’ Japan Times, http://www.japantimes.co.jp/news/2013/05/21/reference/fukushima-no-1-cant-keep-its-head-above-tainted-water/#.UZpke8oQNX9, date accessed 21 May 2013

[ii] S. Kimura (6 April 2013) ‘120 Tons of Contaminated Water Leaks at Fukushima Nuclear Plant’, The Asahi Shimbun, http://ajw.asahi.com/article/0311disaster/fukushima/AJ201304060038, date accessed 7 April 2013.

[iii] Yoshida ‘Fukushima No. 1 Can’t Keep its Head Above Tainted Water.’

[iv] R. Mackey and R. Somaiya (1 November 2011) ‘Japanese Official Drinks Water From Fukushima Reactor Buildings’, The New York Times, http://thelede.blogs.nytimes.com/2011/11/01/japanese-official-drinks-water-from-fukushima-reactor-buildings/, date accessed 3 November 2011.

Source : http://majiasblog.blogspot.fr/2017/08/tritium-in-us-all.html

August 10, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Groundwater level plunges near Fukushima reactor

The reason they didn’t divert the groundwater around Daiichi is because they need it to keep all the missing stuff cool & contained, relatively speaking …

“A sharp fall in the groundwater level just outside reactor buildings could cause contaminated water to leak from inside the buildings.”

 

20170804_06_361779_L

 

The operator of the Fukushima Daiichi nuclear power plant says the groundwater level briefly plummeted near a building that houses one of the crippled reactors.

Tokyo Electric Power Company, or TEPCO, says the fall was observed in a monitoring well about 11 meters southwest of the No.4 reactor building on Wednesday.

The utility says the groundwater level temporarily sank roughly 1 meter below the level of contaminated water inside the reactor building.

The firm says the groundwater rose above the usual level 23 minutes later.

A sharp fall in the groundwater level just outside reactor buildings could cause contaminated water to leak from inside the buildings.

TEPCO says it assessed the density of radioactive substances in the well water on Thursday and has confirmed no leak of contaminated water took place.

TEPCO stopped pumping out water from the well and reported the case to relevant local governments and the Nuclear Regulation Authority.

The company says it is conducting an investigation, suspecting that improvement work on another well 6 meters away may have caused the drop.

The utility publicized the drop on Thursday, one day after the phenomenon was recorded. The firm apologized for the delay in disclosure, saying it initially decided a problem had developed with the well’s water gauge as the water level in a nearby well remained unchanged.

The No.4 reactor building experienced a hydrogen explosion, but not a meltdown, during the 2011 accident.

https://www3.nhk.or.jp/nhkworld/en/news/20170804_06/

August 7, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Nuclear fuel debris to be collected from 2021

31 july 2017.jpg

 

A government advisory body has compiled a draft blueprint for recovering nuclear fuel debris from the No. 1 to 3 reactors that melted down at Tokyo Electric Power Company Holdings Inc.’s Fukushima No. 1 power plant, it has been learned.

According to the draft from the Nuclear Damage Compensation and Decommissioning Facilitation Corporation, the recovery project will prioritize collection of debris that has piled up at the bottom of the reactors, installing a robot arm into the reactor containment vessels from the side and controlling it remotely as its main operation.

The aim is to start the project in 2021. All the decommissioning work is expected to be completed sometime from 30 to 40 years after the disaster occurred.

The draft was presented Monday at an expert panel meeting held by the Economy, Trade and Industry Ministry in Iwaki, Fukushima Prefecture, to discuss ways to decommission reactors and get rid of contaminated water. The government will decide sometime in September, based on the blueprint, on a means to remove debris from each reactor.

Fuel penetrated pressure vessels that contain reactor cores, causing debris to form at different levels on the bottom of the containment vessels of the Nos. 1 to 3 reactors.

It was decided to recover the fuel from the side because that will allow work to retrieve fuel from spent pools located in the upper part of the reactor buildings to be conducted at the same time. If recovery was attempted from above, the robot arm would have to reach down to the bottom of the containment vessels, about 30 meters away. The distance would be only about 10 meters if the arm is installed from the side, making it easier to work on the project. The draft deems it feasible to recover debris from the side to get things started.

Details will be discussed in the future, but the draft suggests making use of holes in the containment vessels’ wall or boring new ones, from which the robot arm can be installed to be operated remotely.

Fuel debris

A substance created when atomic fuel such as uranium reaches high heat, begins to melt with metal fuel cladding and the material of the reactor’s structure, and then consolidates. The shape, hardness and content of debris vary depending on how it was formed, so it can resemble rocks, pebbles or sand. When recovering it, care must be taken not to trigger recriticality.

http://the-japan-news.com/news/article/0003852307

August 7, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Radioactive Contamination of Oceans: Sellafield, La Hague, Fukushima

Frankly speaking, I find it amazing that the people and the media talk so much about Fukushima Daiichi having leaked contaminated water into the Pacific Ocean since March 2011, and about Tepco possible future release of the tritiated water accumulated on site into the Pacific Ocean.

Whereas nobody ever talks about how much contaminated water the Sellafield nuclear fuel reprocessing site on England’s west coast has been releasing into the Irish Sea (then from there flowing into the Atlantic Ocean), and how much contaminated water the La Hague nuclear fuel reprocessing site on France west coast has been releasing into the English Channel (then from there flowing into the Atlantic Ocean.

If you think that Fukushima Daiichi is contaminating the Pacific Ocean since 2011, why are aren’t you aware that Sellafield and La Hague have been contaminating the Atlantic Ocean for decades already?

Both sites having large pipes underwater going far from the land into the sea, both releasing their contaminated water at sea now for decades, with the gracious authorization of the IAEA.

https://en.wikipedia.org/wiki/Sellafield
https://en.wikipedia.org/wiki/La_Hague_site

It might be because few people actually know about it, or because it is easier to point the finger to somebody else far away than at home. Of course it also serves the political and economic interests of both England and France to make their people mindful of what’s happening over there in Fukushima while keeping them blind about what’s happening in their own backyards, their media editors knowing very well what issues are to be avoided as too sensitive to be handled.

Of course I am not saying that the radioactive contamination of the Pacific Ocean by Fukushima Daiichi should not be published, not looked into, not adressed.

What I am saying is that the radioactive contamination of the Atlantic by Sellafield and La Hague in parallel should be also published, looked into, as much adressed, not swept under the carpet, and the people well informed about it, especially as this has been going on for decades authorized by the IAEA.

 

A few related articles about Sellafield :

There is more radioactive plutonium in the sediments off the Sellafield plant in the Irish Sea than at the underwater Russian Novaya Zemlya nuclear weapons test site, according to Greenpeace.

The environmental group yesterday released further data arising from its ongoing survey of the Irish Sea. It has been measuring radioactive contamination in sediments and seaweed along British and Irish coasts for several weeks. Last week it visited Dundalk bay, retrieving seaweed as part of this activity. The data released yesterday related to the plutonium and caesium content of sediment taken adjacent to a Sellafield waste-discharge pipe two kilometres off the Cumbrian coast.”

June 1988 : Irish Sea radioactivity `worse than at nuclear site’ https://www.irishtimes.com/news/irish-sea-radioactivity-worse-than-at-nuclear-site-1.161463

 

“A record number of radioactive hotspots have been found contaminating public beaches near the Sellafield nuclear complex in Cumbria, according to a report by the site’s operator.

As many as 383 radioactive particles and stones were detected and removed from seven beaches in 2010-11, bringing the total retrieved since 2006 to 1,233. Although Sellafield insists that the health risks for beach users are “very low”, there are concerns that some potentially dangerous particles may remain undetected and that contamination keeps being found.”

July 2012 : Record number of radioactive particles found on beaches near Sellafield https://www.theguardian.com/environment/2012/jul/04/radioactive-particles-beaches-sellafield

 

“Greenpeace has warned that the dumping of the reprocessing plant’s liquid waste has made the Irish Sea among the most contaminated waters in the world, even though Ireland itself produces no nuclear energy. Irish fishermen have been angered by catches of unsaleable mutated fish and by findings that they have been exposed to low-level radiation.”

Jan 2014 : Irish free to sue British nuclear operators over contamination http://www.independent.co.uk/news/uk/home-news/irish-free-to-sue-british-nuclear-operators-over-contamination-9039178.html

 

“Radioactive waste from the Sellafield nuclear plant in Cumbria is contaminating shellfish hundreds of kilometres away on the west coast of Scotland, according to a new scientific study.

Scottish researchers discovered traces of radioactive carbon discharged from Sellafield in the shells of mussels, cockles and winkles as far north as Port Appin in Argyll, 160 miles from the notorious nuclear plant.”

December 2015 : Scottish shellfish are contaminated by radioactive waste from Sellafield http://www.heraldscotland.com/news/14157272.Scottish_shellfish_are_contaminated_by_radioactive_waste_from_Sellafield/

 

A few related articles about La Hague :

According to the ACRO, in general, “there is more tritium in the Channel than in the Pacific waters near the Fukushima power station”. (They certainly should know as they regualarly monitor and analyze the contamination near La Hague, and they have repeatedly traveled to Fukushima to cooperate with the Iwaki Mother’s Radiation Lab to measure contamination there). http://www.lemonde.fr/planete/article/2013/03/28/concentration-anormale-en-tritium-relevee-dans-la-mer-a-proximite-de-la-hague_3149613_3244.html#UGUVieKghcxVdjVv.99

The tritium rejected at La Hague is 1,000 times higher than what is allowed at the nearby Flamanville nuclear plant.” https://www.franceculture.fr/emissions/lsd-la-serie-documentaire/lombre-des-centrales-nucleaires-44-des-poubelles-radioactives

 

Conclusion from my friend Pierre Fetet (Fukushima’s blog) :

“There are several differences between La Hague and Fukushima (for Sellafield, I do not know enough):

At La Hague, for example, there is an authorization to reject 50,000 billion Bq of Tritium per day.

While in Fukushima, it is not known at all how much is continuously discharged into the sea in terms of radioactivity, except that it is 300 tons per day of contaminated water and that is not authorized by anyone.

The big difference is that in France that crime is allowed but confidential and that in Fukushima that crime is suffered and mediatized.

But you’re right Hervé, people are not aware and remain uninformed of what is really going on.”

 

For information: Releases by La Hague

20637872_10214212853938087_5602193404803544621_n.jpgAnnual Radionuclide Releases Report in terabecquerel (1 terabecquerel = 1 000 000 000 000 becquerels )

 

Special credits to Pierre Fetet and Javale Gola

August 3, 2017 Posted by | radiation | , , , , , | 1 Comment

Installation of Unit 3 fuel removal cover dome roof at Fukushima Daiichi

Tokyo Electric Power Co. shows its installation work to cover the upper part of the No. 3 nuclear reactor building that was blown off by the March 2011 hydrogen explosion at the Fukushima No. 1 nuclear power plant.

 

OKUMA, Fukushima Prefecture–Tokyo Electric Power Co. showed reporters its progress in installing a new roof above Fukushima No. 1 nuclear plant’s No. 3 reactor building on Aug. 2, ahead of work to remove spent nuclear fuel from a storage pool.

The company demonstrated how it is carrying out the work, which is necessary because the upper section of the reactor building was blown off in a hydrogen explosion in the nuclear disaster at the plant in March 2011.

The roof project marks a step toward removing nuclear fuel assemblies in the spent nuclear fuel storage pool in the building.

august 2 2017 new roof reactor 3.jpgA photograph taken from an Asahi Shimbun helicopter shows a section of the half-tubular shaped roof being installed over the No. 3 reactor building at the Fukushima No. 1 nuclear power plant on Aug. 2.

 

To prevent the spread of radioactive material, TEPCO started to set up the half-tubular shaped cover to shield the damaged reactor building at the end of last month.

new roof for reactor 3 august 2 2017 2.jpgA section of the roof is lifted by a crane to place it on top of the No. 3 nuclear reactor building at the Fukushima No. 1 nuclear power plant on Aug. 2.

 

new roof for reactor 3 august 2 2017 3An artist’s rendition of the completed roof that will shield the upper part of the No. 3 nuclear reactor building that was blown off in the March 2011 hydrogen explosion at the Fukushima No. 1 nuclear power plant.

 

The 566 nuclear fuel assemblies currently lying in the pool will become a significant risk if another major disaster strikes the area.

TEPCO is expected to start removing the fuel from around mid-fiscal 2018.

Early on Aug. 2, part of the roof measuring around 17 meters high and weighing 37 tons was lifted to the top floor of the reactor building with a large crane.

Workers connected the new part of the cover to another section that had been installed at the end of July, completing one eighth of the roof. When finished, it will be about 60 meters long.

Dedicated removal machines are needed to retrieve the fuel from the storage pool. The machines that had been used at the plant prior to the accident were removed because they were severely damaged by the hydrogen explosion.

http://www.asahi.com/ajw/articles/AJ201708020046.html

Source : Tepco

2017.7.31 Installation of Unit 3 fuel removal cover dome roof at Fukushima Daiichi Nuclear Power Station

http://www.tepco.co.jp/en/news/library/archive-e.html?video_uuid=z2v3h93c&catid=61785

Installation of Unit 3 spent fuel removal cover dome roof at Fukushima Daiichi Nuclear Power Station (On-site demonstration) Photos taken on: Aug 2, 2017

http://www.tepco.co.jp/en/news/library/archive-e.html?video_uuid=w8a3j0h4&catid=69631

August 3, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Tritium at Fukushima: A Primer

There is much to be said about Tritium and Fukushima. I strongly recommend watching this interview with Kevin Kamps on Fukushima conditions, including and especially the huge volumes of tritiated water stored at the site:

 

Tritium is quite devious because its difficult to detect internally.
I’ve been thinking quite a bit about tritium. My friend Clyde Stagner introduced me to the ubiquity and dangers of tritium in the environment. You can read his book (Hidden Tritium at Amazon) and my blog description of his work here.

Today I had lunch with a friend who is an atmospheric chemist and we discussed how tritium in fog, or tritiated fog, might differ from ordinary fog.

We had a great discussion that I will follow up on later with implications drawn for webcam watching.

Living downwind from the Palo Verde Nuclear Power plant, and swimming quite often in open water, I imagine that I bear a certain number of hydrogen atoms with two neutrons, an isotope of hydrogen called Tritium, found rarely on earth before the twentieth century, but common in the upper atmosphere. On earth, tritium finds oxygen and binds to create tritiated water.

How radioactive am I compared to my ancestors who lived before the nineteenth century?

Related posts:

LTR-13-0077 – Clyde Stagner Ltr. re: Concerns regarding tritium in …

https://www.nrc.gov/docs/ML1303/ML13030A330.pdf

Jan 29, 2013 – Clyde Stagner … Subject: Tritium in Phoenix & People of Phoenix … an AMERSHAM PLANT in Cardiff, Wales (Ref: Figure 3,”Hidden Tritium“.

Majia’s Blog: Tritium in Swimming Pools

majiasblog.blogspot.com/2012/05/tritium-in-swimming-pools.html

May 13, 2012 – Stagner has calculated the probable concentration of tritium in swimming … Clyde Stagner’s book, Hidden Tritium, can be found at Amazon.com.

Majia’s Blog: Tritium and Nuclear Power Plants: “Blowdown” Worsens …

majiasblog.blogspot.com/2013/01/tritium-and-nuclear-power-plants.html

Jan 22, 2013 – My friend Clyde Stagner studied tritium emissions and … Stagner is author of Hidden Tritium and has had a long, distinguished career, .

Majia’s Blog: Encanto Park and Radioactive Tritium

majiasblog.blogspot.com/2012/08/encanto-park-and-radioactive-tritium.html

Aug 14, 2012 – Capt Stagner is petitioning the NRC to resume tritium monitoring in …. Clyde Stagner’s book, Hidden Tritium, can be found at Amazon.com.

Majia’s Blog: Tritium Contaminating Our Environment: A Letter …

majiasblog.blogspot.com/2012/07/tritium-contaminating-our-environment.html

Jul 17, 2012 – Monitoring of tritium in the area stopped after 2010 despite rising levels …. Clyde Stagner’s book, Hidden Tritium, can be found at Amazon.com.

Related article:

Impact of low doses of tritium on the marine mussel, Mytilus edulis: genotoxic effects and tissue-specific bioconcentration.

https://www.ncbi.nlm.nih.gov/pubmed/16039156

Source :

http://majiasblog.blogspot.fr/2017/08/tritium-at-fukushima-primer.html

 

 

 

 

August 3, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Inside Fukushima Daiichi Unit 3 Robot Probe Inspections

TEPCO released three videos of its robot probe inspections inside unit 3. The videos provided some interesting information, showing some unexplained “blobs”, thick adhered substances, concrete spalling seen in fires, possible melted fuel formations, and thought to be solidified melted fuel around the lower end of a control rod.

TEPCO think the graphite gaskets sealing the control rod holes in bottom of the reactor vessel melted allowing molten fuel to flow through these holes to drip down into the reactor pedestal. Structures in the pedestal show some of the patterns created by the thick substances that appear to have splattered around the containment structures.

TEPCO cites 364 tons of fuel debris (melted fuel, internal reactor parts and control rods) to be expected at unit 3. The videos only show very small views of the damage found making it difficult to determine how much fuel debris was actually found inside unit 3’s pedestal.

 

 

 

Source : Tepco

http://www.tepco.co.jp/en/news/library/archive-e.html?video_uuid=qf64ne97&catid=61785

http://www.tepco.co.jp/en/news/library/archive-e.html?video_uuid=o6lm23vu&catid=61785

http://www.tepco.co.jp/en/news/library/archive-e.html?video_uuid=u10b97j8&catid=61785

August 3, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

How to Clean Up Hundreds of Tons of Melted Nuclear Fuel

In more than 6 years they have not been able to really find yet the melted fuel, despite their beautiful PR stunt last week, and now they talk about which techniques to use to remove it. Maybe they should better find it first before talking how to remove it, that is if most of it has not been already vented and projected into our skies.

gghjkl.jpg

 

How to Clean Up Hundreds of Tons of Melted Nuclear Fuel

More than six years after three nuclear reactors melted down in Japan, the country is homing in on the lost fuel inside one of them. Japan’s biggest utility and owner of the wrecked Fukushima Dai-Ichi plant, Tokyo Electric Power Co. Holdings Inc., last week released images that for the first time showed what’s likely melted fuel inside the No. 3 reactor.

If confirmed, the nation will have to devise a way to remove the highly radioactive material, a mixture of melted nuclear fuel and reactor debris known as corium. The cleanup process that may last 40 years and cost 8 trillion yen ($72 billion) will require technology not yet invented.

Here are a few ways the removal could be done, including the government’s preferred approach by taking it out the side:

-1x-1.png

 

Special tools and techniques will have to be developed to undertake such a task that has never been attempted before anywhere in the world,” said Dale Klein, an adviser to Tepco, as the utility is known, and a former chairman of the U.S. Nuclear Regulatory Commission. “Once Tepco has identified the characteristics of this material, then they can develop a plan to remove this material in a safe manner.”

-1x-1 2.png

 

The search for the fuel has left a trail of dead experimental robots specifically designed to find and photograph the estimated combined 600 metric tons of fuel and debris in the three melted reactors. While the No. 3 reactor was the last unit to be probed, its the first to produce a strong indication of where the fuel came to rest. The removal process is slated to begin in 2021.

-1x-13.png

 

Long-handled devices guided by a television monitor system were developed to remove fuel core debris at Three Mile Island in the U.S. after its 1979 meltdown. The so-called defueling process took from 1985 to 1990 and involved removing the partially melted fuel core from inside the pressure vessel of the No. 2 reactor, which remained intact. Fukushima offers a more complex challenge since three reactors suffered total meltdowns, with melted fuel rupturing pressure vessels and falling to the bottom of the units.

No such effort is being made at Chernobyl, where a concrete sarcophagus was used to entomb the wrecked plant that melted down in 1986.

Technology research and development should focus on removing fuel through the side, the Nuclear Damage Compensation & Decommissioning Facilitation Corp., Tepco’s top government shareholder, said Monday. That method is safer for workers than flooding the reactor, which would also require the management of radioactive water.

Japan will decide how it will remove the fuel by September, Industry Minister Hiroshige Seko said after the discovery last week, according to national broadcaster NHK.

https://www.bloomberg.com/news/articles/2017-07-31/how-japan-could-remove-melted-nuclear-fuel-it-hunted-for-6-years

 

31 july 2017 fuel removal technique.jpg

New proposal suggests removing Fukushima plant’s melted nuclear fuel from side

A method to remove melted nuclear fuel debris on the bottom of the containment vessels of Fukushima No. 1 Nuclear Power Plant’s first, second and third reactors from the side was proposed by the Nuclear Damage Compensation and Decommissioning Facilitation Corporation (NDF) on July 31.

Hajimu Yamana, head of the NDF, which is tasked with considering how to remove fuel debris from the reactors, for the first time explained the organization’s specific method proposal to the heads of local governments at a countermeasures for the decommissioning and handling of the contaminated water council meeting held in Iwaki, Fukushima Prefecture.

The method would focus on prioritizing the removal of debris from the bottom of the vessels from the side, using robotic arms and other remote devices while flushing water over the debris.

However, ways to block radiation and countermeasures against the scattering of airborne radioactive dust still remain unsolved. The central government and Tokyo Electric Power Co. (TEPCO) plan to finalize their policy to remove the debris and amend the decommission schedule in September.

In all three of the reactors, contaminated water has collected at the bottom of the containment vessels. The NDF had previously considered a “flooding method” that would fill the containment vessels completely with water to block radiation from leaking. However, measures to repair the containment vessels and prevent leakage of the radioactive water would be difficult, so the plan was put aside for having “too many issues.”

https://mainichi.jp/english/articles/20170801/p2a/00m/0na/014000c

August 3, 2017 Posted by | Fukushima 2017 | , , | Leave a comment