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

” 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. 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.

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 decrease, 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. “

by The Mainichi

source

The comic strip journalist who reports on the fallout from Fukushima — The Spinoff

” 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”.

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.”

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.

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.” “

by Guy Somerset, The Spinoff

source with comic strip photos

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

” 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.” “

by The Mainichi

source

Radioactively-hot particles detected in dusts and soils from Northern Japan by combination of gamma spectrometry, autoradiography, and SEM/EDS analysis — Marco Kaltofen, Arnie Gundersen, ScienceDirect

“Abstract

After the March 11, 2011, nuclear reactor meltdowns at Fukushima Dai-ichi, 180 samples of Japanese particulate matter (dusts and surface soils) and 235 similar U.S. and Canadian samples were collected and analyzed sequentially by gamma spectrometry, autoradiography, and scanning electron microscopy with energy dispersive X-ray analysis. Samples were collected and analyzed over a five-year period, from 2011 to 2016. Detectable levels of 134Cs and 137Cs were found in 142 of 180 (80%) Japanese particulate matter samples. The median radio-cesium specific activity of Japanese particulate samples was 3.2 kBq kg− 1 ± 1.8 kBq kg− 1, and the mean was 25.7 kBq kg− 1(σ = 72 kBq kg− 1). The U.S. and Canadian mean and median radio‑cesium activity levels were < 0.03 kBq kg− 1. U.S. and Canadian samples had detectable 134Cs and 137Cs in one dust sample out of 32 collected, and four soils out of 74. The maximum US/Canada radio-cesium particulate matter activity was 0.30 ± 0.10 kBq kg− 1. The mean in Japan was skewed upward due to nine of the 180 (5%) samples with activities > 250 kBq kg− 1. This skewness was present in both the 2011 and 2016 sample sets.

300 individual radioactively-hot particles were identified in samples from Japan; composed of 1% or more of the elements cesium, americium, radium, polonium, thorium, tellurium, or strontium. Some particles reached specific activities in the MBq μg− 1 level and higher. No cesium-containing hot particles were found in the U.S. sample set. Only naturally-occurring radionuclides were found in particles from the U.S. background samples. Some of the hot particles detected in this study could cause significant radiation exposures to individuals if inhaled. Exposure models ignoring these isolated hot particles would potentially understate human radiation dose. ”

source to purchase whole study

Japan pictures likely show melted Fukushima fuel for first time — Bloomberg

” New images show what is likely to be melted nuclear fuel hanging from inside one of Japan’s wrecked Fukushima reactors, a potential milestone in the cleanup of one of the worst atomic disasters in history.

Tokyo Electric Power Co. Holdings Inc., Japan’s biggest utility, released images on Friday showing a hardened black, grey and orange substance that dripped from the bottom of the No. 3 reactor pressure vessel at Fukushima, which is likely to contain melted fuel, according to Takahiro Kimoto, an official at the company. The company sent a Toshiba-designed robot, which can swim and resembles a submarine, to explore the inside of the reactor for the first time on July 19.

“Never before have we taken such clear pictures of what could be melted fuel,” Kimoto said at a press briefing that began at 9 p.m. Friday in Tokyo, noting that it would take time to analyze and confirm whether it is actually fuel. “We believe that the fuel melted and mixed with the metal directly underneath it. And it is highly likely that we have filmed that on Friday.”

If confirmed, the substance — which has the appearance of icicles — would be the first discovery of the fuel that melted during the triple reactor accident at Fukushima six years ago. For Tokyo Electric, which bears most of the clean-up costs, the discovery would help the utility design a way to remove the highly-radioactive material.

The robot, which is about 30 centimeters (12 inches) long, will search for melted fuel at the bottom of the reactor on Saturday. It is possible that the company will take more pictures of what could be melted fuel spread across the floor and lower levels, according to Tokyo Electric’s Kimoto. Fuel from a nuclear meltdown is known as corium, which is a mixture of the atomic fuel rods and other structural materials.

Early Signs

“It is important to know the exact locations and the physical, chemical, radiological forms of the corium to develop the necessary engineering defueling plans for the safe removal of the radioactive materials,” said Lake Barrett, a former official at the U.S. Nuclear Regulatory Commission who was involved with the cleanup at the Three Mile Island nuclear power plant in the U.S. “The recent investigation results are significant early signs of progress on the long road ahead.”

Because of the high radioactivity levels inside the reactor, only specially designed robots can probe the unit. And the unprecedented nature of the Fukushima disaster means that Tepco, as the utility is known, is pinning its efforts on technology not yet invented to get the melted fuel out of the reactors.

Removal Plans

The company aims to decide on the procedure to remove the melted fuel from each unit as soon as this summer. And it will confirm the procedure for the first reactor during the fiscal year ending March 2019, with fuel removal slated to begin in 2021.

Decommissioning the reactors will cost 8 trillion yen ($72 billion), according to an estimate in December from the Ministry of Economy, Trade and Industry. Removing the fuel is one of the most important steps in a cleanup that may take as long as 40 years.

Similar to the latest findings on Friday, Tepco took photographs in January of what appeared to be black residue covering a grate under the Fukushima Dai-Ichi No. 2 reactor, which was speculated to have been melted fuel. However, a follow-up survey by another Toshiba-designed robot in February failed to confirm the location of any melted fuel in the reactor after it got stuck in debris.

A robot designed by Hitachi-GE Nuclear Energy Ltd. also failed to find any melted fuel during its probe of the No. 1 reactor in March.

The significance of Friday’s finding “might be evidence that the robots used by Tepco can now deal with the higher radiation levels, at least for periods of time that allow them to search parts of the reactor that are more likely to contain fuel debris,” M.V. Ramana, professor at the Liu Institute for Global Issues at the University of British Columbia, said by email.

“If some of these fragments can be brought out of the reactor and studied, it would allow nuclear engineers and scientists to better model what happened during the accident.” ”

by Stephen Stapczynski, Bloomberg

source

Japanese robot probes the radioactive water at Fukushima’s nuclear reactor to find melted fuel — Daily Mail

” A Japanese robot has begun probing the radioactive water at Fukushima’s nuclear reactor.

The marine robot, nicknamed the ‘little sunfish’, is on a mission to study structural damage and find fuel inside the three reactors of the devastated plant.

Experts said remote-controlled bots are key to finding fuel at the dangerous site, which has likely melted and been submerged by highly radioactive water.

The probe – about the size of a loaf of bread – is equipped with lights, manoeuvres using tail propellers and collects data using two cameras and a dosimeter radiation detector.

Plant operators chose to send the robot inside the containment vessel of the No. 3 reactor because it has highest known water levels out of the the three reactors.

The robot entered the structure at 6.30am JST (10.30 BST, 5.30 ET) through a pipe connected to the containment vessel.

The marine machine, which was attached to cables, then swam to the area just below the reactor pressure vessel inside to take images.

New images taken by the robot show how parts of the system, including the control rod, have been damaged by radiation.

On Friday, the robot will continue its travels to the bottom of the containment vessels, where melted fuel deposits are believed to have accumulated.

In 2011, a 10-metre-high tsunami that killed nearly 19,000 people crashed into Japan’s Fukushima nuclear power plant, leading to several meltdowns.

Five years after the disaster, researchers are still struggling to clean up the highly dangerous radioactive materials in water of the wasting reactors.

It’s estimated that plant officials have only located 10 per cent of the waste fuel left behind after the nuclear meltdowns.

And the damaged plant is believed to be leaking small amounts of the radioactive waste into the Pacific Ocean, which could be travelling as far as the west cost of the US.

Researchers are now pinning their hopes on the remote-controlled sunfish robot to locate the lost fuel in order to work out the safest way to remove it.

During a demonstration of the device at a test facility near Tokyo last month, the probe slowly slid down from a rail and moved across the water.

A team operated it remotely, with one guiding the robot while another adjusted a cable that transmits data and serves as its lifeline.

Japan hopes to locate and start removing fuel from the reactors after Tokyo’s 2020 Olympics.

In earlier operations, snake and scorpion-shaped robots became stuck inside two reactors.

The scorpion robot’s crawling function failed and it was left inside the plant’s Unit 2 containment vessel.

The other, designed for cleaning debris for the ‘scorpion’ probe, was called back after two hours when two of its cameras stopped working after its total radiation exposure reached 1,000 Sievert – a level that would kill a human within seconds.

The plan had been to use the robot for 10 hours at an exposure level of 100 Sievert per hour.

The swimming robot shown was co-developed by electronics and energy giant Toshiba and the government’s International Research Institute for Nuclear Decommissioning. “

by Daisy Dunne, Mail Online and Associated Press

source with photos and video