The No. 1 reactor building, left, and the No. 2 reactor building at the crippled Fukushima No. 1 nuclear plant
Plans to remove fuel rods from two spent fuel pools at the Fukushima No. 1 nuclear plant will be delayed by up to three years because of difficulties in clearing debris and reducing radiation levels.
The government and plant operator Tokyo Electric Power Co. originally expected to start emptying the storage pools at the No. 1 and No. 2 reactor buildings in fiscal 2020.
But they plan to move the starting time to fiscal 2023 in their first review in two years of the roadmap for decommissioning the stricken nuclear plant, sources said Sept. 20.
They are expected to announce the revised roadmap later this month.
A survey of the upper levels of the two reactor buildings, where the storage pools are located, found debris piled up in a much more complicated way than initially envisaged.
That will lengthen the time needed to clear the debris, thus delaying the removal of the fuel rods, the sources said.
In addition, radiation levels remain extremely high inside the buildings.
The No. 1 reactor’s storage pool holds 392 nuclear fuel assemblies, while the No. 2 reactor’s pool has 615 assemblies.
Work to remove the 566 assemblies from the No. 3 reactor’s pool is scheduled to begin in the middle of fiscal 2018 as originally planned.
The three reactors melted down in the 2011 disaster, triggered by the magnitude-9.0 Great East Japan Earthquake and tsunami.
The review of the decommissioning roadmap is also expected to revise the target of “starting the removal” of melted nuclear fuel and debris in the three reactors in 2021 to “aiming to start the removal” in 2021.
But the government and TEPCO will maintain the goal of completing the decommissioning in “30 to 40 years,” the sources said.
http://www.asahi.com/ajw/articles/AJ201709210034.html
September 22, 2017
Posted by dunrenard |
Fukushima 2017 | Fuel Removal, Fukushima Daiichi, Spent fuel Pools |
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A step in the decommissioning of Japan’s crippled Fukushima Daiichi nuclear plant could be delayed by 3 years.
Japan’s government and the plant operator say they need more time before they remove spent nuclear fuel rods in 2 of the reactors. The rods are in storage pools and now won’t be removed until fiscal 2023. They say they first need to remove rubble and radioactive substances.
The plan to remove molten fuel debris has not changed. This step is considered the biggest hurdle to decommissioning the plant.
The plant went into triple meltdown following the 2011 earthquake and tsunami. It’s expected to take 40 years to scrap the plant.
https://www3.nhk.or.jp/nhkworld/nhknewsline/nuclearwatch/nuclearfuelretrievaldelayed/
September 20, 2017
Posted by dunrenard |
Fukushima 2017 | Fuel Retrieval, Fukushima Daiichi |
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From Majia’s blog
Japan’s Nuclear Regulatory Authority has bowed to pressure and is allowing TEPCO, a company with a culture that has been berated by this same agency, to re-start reactors:
EDITORIAL: NRA too hasty in giving green light to TEPCO to restart reactors (2017, September 14). The Asahi Shimbun, http://www.asahi.com/ajw/articles/AJ201709140030.html
Although the Nuclear Regulation Authority has decided to give the green light to Tokyo Electric Power Co. to restart nuclear reactors, we question the fitness of the utility, which is responsible for the accident at the Fukushima No. 1 nuclear power plant, to manage nuclear facilities. The NRA has been screening TEPCO’s application to resume operations of the No. 6 and No. 7 boiling-water reactors at its Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture. The NRA on Sept. 13 acknowledged with conditions that TEPCO is eligible for operating nuclear plants after examining the company’s safety culture and other issues.
Meanwhile, Japan’s nuclear commission is calling not only for a return to nuclear (with at least 20% of its fuel mix targeted for nuclear), but has also endorsed MOX fuel in a move that defies reason, especially given the conditions of Fukushima reactor 3 (which was running MOX at the time of the accident):
Mari MARI YAMAGUCHI (2017, September 14 ) Japan commission supports nuclear power despite Fukushima. The Seattle Times, http://www.seattletimes.com/business/japan-commission-supports-nuclear-power-despite-fukushima/
TOKYO (AP) — Japan’s nuclear-policy-setting Atomic Energy Commission issued a report Thursday calling for nuclear energy to remain a key component of the country’s energy mix despite broad public support for a less nuclear-reliant society. The report approved by the commission calls for nuclear energy to make up at least 20 percent of Japan’s supply in 2030, citing the government energy plan. It says rising utility costs from expensive fossil fuel imports and slow reactor restarts have affected Japan’s economy. The resumption of the nuclear policy report is a sign Japan’s accelerating effort to restart more reactors. “The government should make clear the long-term benefit of nuclear power generation …
The report also endorsed Japan’s ambitious pursuit of a nuclear fuel cycle program using plutonium, despite a decision last year to scrap the Monju reactor, a centerpiece of the plutonium fuel program, following decades of poor safety records and technical problems. Japan faces growing international scrutiny over its plutonium stockpile because the element can be used to make atomic weapons.
And to top it all off, Japan is now setting up its first “restoration hub” in Futaba:
Noriyoshi Otsuki (2017, September 15). First ‘hub’ set up in Fukushima no-entry zone to speed rebuilding. The Asahi Shimbun, http://www.asahi.com/ajw/articles/AJ201709150058.html
An area in the no-entry zone of Futaba, a town that co-hosts the crippled Fukushima No. 1 nuclear power plant, became the first government-designated “rebuilding hub” after the 3/11 disaster. The designation on Sept. 15 means decontamination will speed up and infrastructure restored so the evacuation order in the town center can be lifted by spring 2022. Most of Futaba is currently located in a difficult-to-return zone because of high radiation levels. Rebuilding efforts have not started there yet, even six-and-a-half years since the nuclear accident unfolded.
As noted in the article, Futaba is located in the difficult to return zone. Here is a screenshot from TEPCO’s 2016 report on air monitoring in the Futaba evacuation zone:


The air dose in Futaba is very high, with the highest reading reported at 9.6 microsieverts an hour.
Locating the first restoration hub in Futaba, located in close proximity to the still-unstable plant, seems like a propaganda move, rather than a thoughtful risk decision.
Fukushima is still belching radioactivity (especially from unit 3), as illustrated in this screenshot from yesterday:

The plant is still at risk from earthquakes and lifequefaction.
I must conclude from this series of news reports that neither Japan nor the US are capable of learning when it comes to nuclear policy making.
http://majiasblog.blogspot.fr/2017/09/nuclear-lessons-learned-us-japan-none.html
September 20, 2017
Posted by dunrenard |
Fukushima 2017 | Fukushima, Fukushima Daiichi |
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Highlights
- • We present new data of 134Cs/137Cs around Fukushima Daiichi Nuclear Power Station.
- • The entire area of the low 134Cs/137Cs ratio anomaly around the FDNPS is revealed.
- • The low 134Cs/137Cs ratio anomaly is coincident with a plume trace.
- • The anomaly occurs in the area which had been contaminated before March 13, 2011.
Abstract
A low 134Cs/137Cs ratio anomaly in the north-northwest (NNW) direction from the Fukushima Dai-ichi Nuclear Power Station (FDNPS) is identified by a new analysis of the 134Cs/137Cs ratio dataset which we had obtained in 2011–2015 by a series of car-borne surveys that employed a germanium gamma-ray spectrometer.
We found that the 134Cs/137Cs ratio is slightly lower (0.95, decay-corrected to March 11, 2011) in an area with a length of about 15 km and a width of about 3 km in the NNW direction from the FDNPS than in other directions from the station.
Furthermore, the area of this lower 134Cs/137Cs ratio anomaly corresponds to a narrow contamination band that runs NNW from the FDNPS and it is nearly parallel with the major and heaviest contamination band in the west-northwest.
The plume trace with a low 134Cs/137Cs ratio previously found by other researchers within the 3-km radius of the FDNPS is in a part of the area with the lower 134Cs/137Cs ratio anomaly that we found.
Our result suggests that this lower 134Cs/137Cs ratio anomaly is the area which was contaminated before March 13, 2011 (UTC) in association with the hydrogen explosion of Unit 1 on March 12, 2011 at 06:36 (UTC) and it was less influenced by later subsequent plumes.
http://www.sciencedirect.com/science/article/pii/S0265931X17301947
September 20, 2017
Posted by dunrenard |
Fukushima 2017 | cesium 134, cesium 137, Fukushima, Fukushima Daiichi, Radioactive Plume |
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This drone will be used to measure radiation inside the reactor and turbine buildings at the meltdown-hit Fukushima No. 1 power plant.
Drone to measure radiation in tainted Fukushima No. 1 buildings
Tokyo Electric plans to measure radiation in heavily contaminated buildings at the Fukushima No. 1 power plant as it prepares to decommission its damaged reactors, officials at the utility said.
The data from the drone is expected to help Tokyo Electric Power Company Holdings Inc. create 3-D maps and identify areas of high radiation that workers should avoid.
The drone, 93 cm wide and 83 cm long, has four propellers and can fly for around 15 minutes. Tepco, as the struggling utility is known, expects to use it in the reactor buildings and the turbine buildings.
In February, Tepco tested a drone in the turbine building for the No. 3 reactor, one of three that experienced meltdowns after the March 2011 earthquake and tsunami.
After improving its performance, it decided to use the drone to gauge radiation but it is still deciding where to start, the officials said.
The government and Tepco want to start debris extraction work in 2021 and are in the process of determining a specific approach for removing the molten fuel from each reactor and updating the decommissioning road map.
https://www.japantimes.co.jp/news/2017/09/09/national/drone-measure-radiation-tainted-fukushima-no-1-buildings/#.WbS8LxdLfrd
Drone to measure radiation inside tainted Fukushima plant buildings
TOKYO (Kyodo) — The operator of the crippled Fukushima Daiichi nuclear power plant is planning to use a drone to measure radiation inside heavily contaminated structures as it prepares to decommission damaged reactors there, according to officials of the operator.
Data obtained from its use is expected to help the operator, Tokyo Electric Power Company Holdings Inc., create 3-D maps and identify areas with high-level radiation inside buildings where workers cannot stay safely.
The drone envisioned for the task is 93 centimeters wide and 83 cm long, and, equipped with four propellers, can fly for around 15 minutes. The operator envisions its use inside buildings that house damaged reactors and inside those housing turbines.
In February Tepco, as it is known, tested a drone inside the turbine building for the No. 3 reactor, one of three reactors that experienced meltdowns in the March 2011 earthquake and tsunami.
After improving its performance, the plant operator has decided to put the drone into use for radiation measurement. But it is still considering where it should begin using the machine, according to the officials.
The government and Tepco are aiming to start debris extraction work from 2021, and are currently in the process of determining a specific approach to removing melted fuel from each damaged reactor and of updating their decommissioning road map.
http://mainichi.jp/english/articles/20170910/p2g/00m/0dm/008000c
September 10, 2017
Posted by dunrenard |
Fukushima 2017 | Drone, Fukushima Daiichi, Radiation Measuring, Reactor Buildings, Turbine Buildings |
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The Fukushima No. 1 nuclear power plant is shown on Feb. 22, 2016. A worker at the plant was found to have been exposed to a small amount of radiation during a routine safety check on Friday.
TEPCO: Worker exposed to small radiation dose at Fukushima
A worker dismantling tanks at Japan’s wrecked Fukushima No. 1 nuclear power plant was found to have been exposed to a small amount of radiation during a routine safety check on Friday, plant operator Tokyo Electric Power Co. (TEPCO) said.
Radiation was detected in nasal cavities of the worker, an unidentified man in his 30s, a TEPCO spokesman said on Friday. The company estimated the amount of radiation at up to 0.010 millisieverts–less than a typical chest X-ray of 0.05 millisieverts–and said it did not pose an immediate health risk.
Reported radiation exposure incidents have been rare during work to clean up the plant, devastated by the March 11, 2011, magnitude 9 earthquake and tsunami that left nearly 16,000 people confirmed dead, with more than 2,000 officially unaccounted for.
The TEPCO spokesman said the last Fukushima No. 1 radiation exposure incident in official records was for a worker exposed to at least 2 millisieverts in January 2012.
http://www.asahi.com/ajw/articles/AJ201709080046.html
Fukushima worker exposed to small amount of radiation, Tepco says
A worker dismantling tanks at the wrecked Fukushima No. 1 nuclear plant was found to have been exposed to a small amount of radiation during a routine safety check on Friday, plant operator Tokyo Electric said.
Radiation was detected in the nasal cavities of the worker, an unidentified man in his 30s, a spokesman for Tokyo Electric Power Company Holdings Inc. said on Friday.
The company estimated the amount of radiation at up to 0.010 millisieverts — less than a typical 0.05-millisievert chest X-ray — and said it did not pose an immediate health risk.
Reported radiation exposure incidents have been rare during work to clean up the plant, which was devastated by a magnitude-9 earthquake and tsunami on March 11, 2011, that left nearly 16,000 people confirmed dead and more than 2,000 officially unaccounted for.
The Tepco spokesman said the last Fukushima No. 1 radiation exposure incident in official records was for a worker who was exposed to at least 2 millisieverts in January 2012.
https://www.japantimes.co.jp/news/2017/09/08/national/fukushima-worker-exposed-small-amount-radiation-tepco-says/#.WbRVGBdLfrc
September 10, 2017
Posted by dunrenard |
Fukushima 2017 | Fukushima Daiichi, Radiation Exposure, Worker |
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Workers from Tokyo Electric Power Co. travel by bus toward the power plant in April 2011.
Ryuta Idogawa traces the onset of his battle with mental illness to a moment not long after his parents had been relocated to Saitama from their hometown of Futaba, Fukushima Prefecture, in the spring of 2011.
Idogawa recalls with almost claustrophobic clarity how, as he boarded a train to travel to Tokyo, a sense of panic set in when the carriage walls seemed to close in and fellow passengers in the rush-hour squash started to stare — piercing, even accusatory stares, he thought.
“I was sweating, but I felt really cold and my heart was racing, faster and faster,” says Idogawa, 33. “I could hardly breathe. I thought, ‘Oh My God! I’m going to die.’”
Today, Idogawa continues to suffer from such panic attacks, although their frequency has decreased. To mitigate the problem, he has found a job near to his apartment and avoids trains whenever possible. On occasions when rail travel is unavoidable, he steers clear of express trains, as there are fewer opportunities to “escape” should panic set in, he explains. Medication, too, has sometimes helped.
One likely cause of this continuing condition, he believes, is guilt — guilt that in the aftermath of the March 11, 2011, disasters that struck northeastern Japan and claimed 18,455 lives (including 2,561 still listed as missing), he was powerless to prevent the accident that occurred at his place of work, the Fukushima No. 1 nuclear power plant.
“At the beginning I wasn’t even aware of my condition, or I felt somehow separate from it and from what was happening,” says Idogawa, a former employee at plant operator Tokyo Electric Power Co. “Looking back, maybe I was hiding it or hiding from it.”
Such mental afflictions are not unusual among Tepco’s Fukushima plant workers, especially in the aftermath of the disasters, experts say. According to a study of some 1,500 workers compiled by Jun Shigemura and others, all had experienced a variety of stressors (see table on page 12) relating to their direct experiences of the disasters, losses of loved ones and the backlash from a disgruntled public, in particular the 160,000 Fukushima residents who were evacuated due to the contamination of their homes and land that resulted from the multiple reactor meltdowns at Fukushima No. 1.
Jun Shigemura, an associate professor at the National Defense Medical College’s department of psychiatry, sits at his office in Tokorozawa, Saitama Prefecture, on Aug. 15.

According to lead researcher Shigemura, 29.5 percent of workers at the plant subsequently displayed symptoms of high post-traumatic stress responses (PTSR), including flashbacks and avoidance of reminders of the terrifying events they went through.
Around 1 in 5 Tepco workers at neighboring Fukushima No. 2 plant also showed similarly high levels of PSTR, even though there was no serious damage to the four reactors there.
Continued surveys of the workers by Shigemura, an associate professor at the National Defense Medical University’s Department of Psychiatry, and other experts say that while the overall influence of disaster-related experiences on PTSR of workers had decreased since 2011, it remains high.
“For some workers, this is going to continue for a long time, probably years and decades,” says Shigemura, who specializes in the mental health of disaster workers.
This is consistent with previous findings following the Chernobyl nuclear accident in 1986, he says. While scientists then had assumed that cancers and other malignant disorders would be the biggest health risk, mental health issues turned out to be far more prevalent, he says.
Indeed, studies have shown that mental health problems, including post-traumatic stress disorder (PTSD), depression and suicide ideation, were still high and remained the most prevalent problem for the Chernobyl cleanup workers even 20 years after the disaster, Shigemura says. “So I think we can say with some confidence that the Fukushima workers also carry a very high risk of developing long-term mental health issues.”
Furthermore, while PTSD is often thought of as the main persisting illness in such disasters, Shigemura says factors such as depression, anxiety and alcohol abuse are also likely to linger for some time.
More than 6½ years on from the Fukushima disasters, former Tepco employee Idogawa knows all about these problems, although how he got there was a gradual, but nonetheless alarming, process.
A graduate of Toden Gakuen, Tepco’s now-defunct training academy, Idogawa had lived and breathed the utility’s doctrine since he was just 15 years old. It centered as much around technical excellence as it did corporate group identity and loyalty, and those who followed it were rewarded with the kind of mouthwatering salaries that placed them very much among the elite of their communities.
Ryuta Idogawa believes that guilt over the nuclear accident that occurred at the Fukushima No. 1 power plant on March 11, 2011, has been a contributor to his continuing struggles with mental illness.
On the day of the disasters, Idogawa was on leave, having worked a night shift the previous day. Even before the Earth’s violent convulsions had subsided, however, he was heading toward the plant from his nearby home, arriving there just before the black waves of the 15-meter mega-tsunami engulfed the facility.
As one of the plant’s operators, his day-to-day duties took place inside the central control room for reactors 1 and 2, where he was charged with scrutinizing the instruments that monitored the plant’s oldest reactor, the outmoded unit 1. By the time he joined the on-duty team of 14 operators, the tsunami had extinguished all available power sources, plunging the control room into complete darkness and disarray.
With monitoring apparatus also dependent on power, there was no way of knowing for certain if coolants were still reaching the reactor cores. Believing that this was unlikely, by midnight Idogawa calculated that the first reactor, and probably the second, were already in meltdown.
This was supported by readings on portable monitoring devices that showed radiation levels inside the control room were climbing. Idogawa joined all the other operators on the reactor 2 side of the windowless room, only venturing over toward the opposite first reactor side, where radiation levels were considerably higher, to make occasional, but futile, checks of the lifeless instruments.
Over the next two days, he remained inside the control room, still in the dark about the safety of his family and friends as meltdowns and explosions began to take their toll.
On March 14, he was ordered aboard a company bus bound for the Fukushima No. 2 nuclear power plant, which had fared far better than its older neighbor and had been designated an off-duty recuperation and medical center for workers at Fukushima No. 1. It was during that 10-kilometer journey that his focus slowly shifted to the outside world, which had a distinctly fishbowl appearance through his full-face mask.
“At one point, just past the entrance to Fukushima No. 1 plant, I looked out of the window and saw a man walking his dog like it was just another ordinary day,” Idogawa says. The scene seemed all the more bizarre because while most workers aboard the bus were wearing masks, the man went about his morning stroll completely unprotected. “I wondered, ‘What is he doing out there’ and wanted to shout out to him to get inside away from the high radiation.”
At the Fukushima No. 2 plant there was a noticeably subdued air. There was little food, no cigarettes and no heat to stay warm amid the snowy, wintery cold.
Idogawa had originally tried to make the trip to the Fukushima No. 2 plant via his own car, which was parked near the newly built quake-proof center at Fukushima No. 1 and was highly contaminated, but he couldn’t get it started.
“I wanted to take the car to give me an escape should things get worse. That’s what I was expecting,” he says. “I actually think that’s what (plant chief Masao) Yoshida was thinking, too — that everyone, himself included, should get out of there and go to the Fukushima No. 2 plant.”
Over the following months, the cumulation of these events began to take their toll. Idogawa became part of a team that the foreign media nicknamed the “Fukushima 50,” groups of workers on rotating shifts that split their time between battling the reactor meltdowns and recuperating at the Fukushima No. 2 plant, or at residences to which they had been evacuated.
With his home now off limits inside the 20-kilometer no-go zone, Idogawa had evacuated to an apartment in Koriyama, where time proved to be anything but a healer. With nothing to do but await his next shift, his mind wandered, among other things, to the man walking his dog and the tens of thousands of residents like him who had been forced to flee their homes as invisible radioactive substances fell on their land.
He began to suffer stomach cramps, chronic insomnia and depression, and turned to the only thing he could think of that would help him sleep and wash away the unwelcome images in his head: whisky — and lots of it.
“I felt bad for those people, like it was my fault,” he says. “I couldn’t do anything (to prevent the accident) and as a member of Tepco, I thought I was to blame.”
Takeshi Tanigawa, a professor of public health at Jutendo University’s graduate school of medicine, has been involved in mental health surveys of Fukushima plant workers.

Such self-criticism and guilt have been major contributors to enduring mental illnesses among plant workers, according to Takeshi Tanigawa, a professor of public health at Jutendo University’s graduate school of medicine, who has also been involved in the mental health surveys of Fukushima plant workers.
“We found that those who have experienced such criticism and discrimination have a high degree of psychological distress or PTSR, more than two times higher than control subjects,” he says, adding that with 80 percent of workers being local hires, the bashing, sometimes at the hands of friends and relatives, was even more difficult to take.
Of all the stressors — including the life-threatening experiences, the loss of loved ones and possessions, and so on — this was the “most influential” among those workers with persisting mental health issues, says Tanigawa, who also has worked as a part-time occupational physician at the nuclear plants in Fukushima Prefecture since 1991.
“One thing we can be grateful for is that nobody has committed suicide at the plant,” Tanigawa says. “However, alcohol abuse, increased smoking and obesity are prevalent, and can lead to life-threatening diseases and early mortality.”
However, both Tanigawa and Shigemura believe that the enduring impact of the various “complex stressors” is the main reason why other contract workers and early respondents to the disasters will not display similar long-term mental health problems. This includes personnel from Tepco’s various subcontracting companies and members of Tokyo Fire Department’s Hyper Rescue brigade, who entered the plant on March 17, 2011, in an attempt to pump water onto the overheating reactor 3.
Yukio Takayama, former deputy superintendent and chief of the 8th district Hyper Rescue battalion, revisits his former workplace in Tachikawa on July 13.

One of the leaders of that Tokyo Fire Department team, Yukio Takayama, who was at the time deputy superintendent of the 8th district Hyper Rescue battalion based in the city of Tachikawa, says a number of firefighters had been deeply affected by the thought of entering such a highly irradiated part of the plant, which offered an invisible fear factor quite different from that to which they were accustomed.
Indeed, Takayama fell sick during the operations and while they left an indelible impression, the 48-hour encounter with the radiation-spewing plant was unlikely to leave any long-term mental scars, he says. “It was stressful, but there were others who were up there for much, much longer,” he says.
A former subcontractor employee, who was working at the Fukushima No. 1 plant at the time of the 2011 disasters, says he had not heard of any mental health issues among subcontractor workers. However, as they made up almost 90 percent of the total plant workforce, he couldn’t discount the possibility.
“One thing that was different for us was that we were never forced, or obliged, to return to the plant,” the worker says in an interview, speaking on condition of anonymity. “Like many others, I evacuated from the plant and never went back, but if I had, I suppose it’s perfectly possible I may have succumbed to mental illness.”
One other group that reportedly has been afflicted by mental health problems comes from an unusual quarter, and one that has not been a factor in previous nuclear accidents. American sailors who were taking part in the U.S. military’s “Operation Tomodachi” relief mission at the time of the Tohoku disasters were inadvertently exposed to a plume of radiation that passed over their ships, which were anchored off the Pacific coast north of Fukushima.
Several hundred have since developed life-changing illnesses, including leukemia and other cancers — a result, they claim, of the radioactive plume. Many have also suffered persisting mental health issues, either due to concerns of physical illnesses that have resulted from the exposure or extreme stress brought about by concerns for potential future illnesses, including cancers.
Sailors aboard the aircraft carrier USS Ronald Reagan scrub the flight deck to decontaminate it while the ship is operating off the coast of Japan providing humanitarian assistance on March 23, 2011.
“Unlike the nuclear plant workers, these sailors had no protective clothing. In fact, some of them literally had no shirts on their backs because they had given all their clothing away to people they saved from the tsunami waves,” says Charles Bonner, a lawyer representing some 400 sailors who have filed a lawsuit against Tepco and U.S. nuclear reactor manufacturer General Electric. “And because they had given away all their bottled water to tsunami survivors, they were drinking desalinated water that had also been contaminated. I do not doubt the psychological impact of the disasters on the plant workers, but at least they had masks and other protective clothing, as required by law. The sailors, however, knew nothing of their exposure and were literally marinated in the radiation.”
Idogawa’s exposure levels were also in excess of acceptable levels by the time he quit Tepco in January 2012 to protest the utility’s poor treatment of workers — who were, in most cases, also victims — and the government’s announcement the previous month that the plant had been brought “under control,” which was completely at odds with what he saw.
“Whether you take the viewpoint of a Tepco employee or a local resident, the outcome was far from satisfactory,” Idogawa says. “As a plant operator we caused a huge accident — the worst kind. Technicians train over and over, and are charged with ensuring this kind of thing doesn’t happen. That the accident did happen makes us the lowest of the low. From the viewpoint of a resident, the disaster meant they couldn’t go home. That we destroyed entire communities was bad enough. However, they were our communities as well.”
Despite his disgruntlement, Idogawa is hopeful that his former employer will implement measures to monitor and treat mental health issues that he believes continue to persist among many workers.
When asked to comment on post-accident care of its workers for this article, Tepco says it was unable to provide details due to privacy issues. It did, however, continue to hand out “health check” questionnaires, the nationalized utility says. The utility also would not comment on its policy regarding on-site care, which came into question following rumors that an on-site psychiatrist fled the Fukushima No. 1 plant following the 2011 disasters.
An employee from Tepco apologizes to a Tomioka resident during a meeting in the city of Koriyama, Fukushima Prefecture, on Feb. 11, 2013.
Shigemura, whose surveys and subsequent treatment of plant workers was brought to an abrupt halt by Tepco in 2015, believes continued “surveillance” of workers is imperative. One reason is due to the possibility of “delayed onset” mental illnesses, which sometimes occur among “survivors” following a variety of situations, from disasters and conflicts to car accidents and familial loss. Some Vietnam War veterans, for example, only developed mental illnesses following the start of the Gulf War 20 years later, he explains.
During his research, Shigemura came across one plant worker, who was also an evacuee, who had experienced such a phenomenon. Three years later, after the evacuation order had been lifted, he re-visited his hometown, which was overgrown and deserted.
“When he evacuated, he hadn’t fully accepted the burden of the disaster,” Shigemura says. “It was only when he returned home that he felt the gravity of the disaster and was forced to confront it. And that’s when he experienced late-onset PTSD.”
Shigemura also believes there is a need for a major reconsideration of disaster management measures, especially those that can mitigate the psychological havoc a nuclear accident can wreak.
“We need multiple layers of support in preparation for these disasters because when they happen people tend to act in ways they might not usually act, especially following a disaster you cannot easily perceive, such as a nuclear accident,” he said. “They might run away and you can’t blame them for that, because they also have roles as fathers, mothers and so on. There needs to be measures to respond effectively to such eventualities and to provide effective care for those most affected.”
Fukushima plant worker stressors
Work-related experience
- Earthquakes and tsunami
- Plant explosions
- Radiation exposure
- Extreme overwork
- Worker shortage
Survivor experience
- Mandatory evacuation
- Property loss
- Family dispersion
Grief — loss of:
- Colleagues
- Family members
- Friends
Social backlash
- Public criticism
- Discrimination
- Harassment
- Guilt as “perpetrators” of a nuclear accident
https://www.japantimes.co.jp/news/2017/09/02/national/science-health/battling-nuclear-demons-mental-health-issues-haunt-first-line-defense-311/#.WasAzxdLfrc
September 3, 2017
Posted by dunrenard |
Fukushima 2017 | Fukushima Daiichi, Post-Trauma |
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Workers wearing protective suits and masks work on the No. 2 reactor building at the Fukushima Daiichi nuclear power plant.
TOKYO – A state-backed entity tasked with supporting the decommissioning of the Fukushima nuclear power station proposed Thursday that melted fuel be removed from the side of three of the crippled reactors as part of the process to scrap the complex.
Based on a formal proposal, the government and the plant operator Tokyo Electric Power Company Holdings Inc (TEPCO) will determine specific approaches to carry out the process on each reactor next month and update the plant decommissioning road map.
Under its strategic plan for 2017, the Nuclear Damage Compensation and Decommissioning Facilitation Corp called for the removal of the fuel by partially filling the three reactors with water to cover some of the nuclear debris while allowing access to carry out the work.
The entity also pointed out that the decommissioning work requires phased efforts while maintaining flexibility, as the project still faces many uncertainties.
The extraction work from the Nos. 1-3 reactors at the Fukushima Daiichi nuclear complex, which suffered meltdowns following the massive 2011 earthquake and tsunami disaster, is seen as the most difficult step toward the ultimate goal of decommissioning the entire complex, set to take at least 30 to 40 years to complete.
The government and TEPCO are currently aiming to start the extraction work from 2021.
Under the plan, the Nuclear Damage Compensation and Decommissioning Facilitation body proposed using a remotely controlled apparatus to shave debris from the underside of the lower section of the reactors’ containment vessel while controlling the level of water.
Debris remains not only in the reactors’ pressure vessel but also piled and scattered at the bottom of the containment vessel that houses the reactor vessel.
As for debris left in the reactors’ pressure vessel, the entity will consider removing it from the upper part of the reactors, it said.
The decommissioning body had previously considered a strategy to fill the containment vessel with water as water is effective in containing radiation, but it has shelved the idea as the reactor containers are believed to have been damaged and would leak.
Following a magnitude-9.0 earthquake in March 2011, tsunami inundated the six-reactor plant, located on ground 10 meters above sea level, and flooded power supply facilities.
Reactor cooling systems were crippled and the three reactors suffered fuel meltdowns, while hydrogen explosions damaged the buildings housing the Nos. 1, 3 and 4 reactors.
The Nuclear Damage Compensation and Decommissioning Facilitation entity was established after the Fukushima crisis, the worst nuclear disaster since Chernobyl, to help the utility pay damages. The state-backed entity holds a majority stake in the operator.
https://japantoday.com/category/national/Debris-to-be-removed-from-side-of-Fukushima-reactors
September 2, 2017
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Fukushima 2017 | decommissioning, Fukushima Daiichi |
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Hitachi-GE testing variety of simply structured, radiation-resistant equipment
The Unit 1 reactor building at the Fukushima Dai-ichi nuclear power plant of the Tokyo Electric Power Co. (TEPCO) in Okuma town, Fukushima prefecture, June 21, 2017.
TOKYO — A joint venture between Japanese and American high-technology power houses Hitachi and General Electric is developing special robots for removing nuclear debris from the Fukushima Daiichi nuclear power plant, the most difficult task in decommissioning the plant’s six reactors, three of which suffered core meltdowns in the March 2011 accident.
The machines under development by Hitachi-GE Nuclear Energy are called “muscle robots,” as their hydraulic springs operate like human muscles. The company, based in Hitachi, Ibaraki Prefecture, is stepping up efforts to complete the development project in time for the start of debris removal in 2021.
Hitachi-GE is testing the arms of the robots at a plant of Chugai Technos, a Hiroshima-based engineering service company, located a 30-minute drive from the center of the city. The testing is taking place in a structure with a life-size model of the primary containment vessel of the No. 1 reactor at the Fukushima plant. The robots awkwardly move about, picking up concrete lumps standing in for fuel debris.
“The robots are based on a concept completely different from those of conventional robots,” said Koichi Kurosawa, a senior Hitachi-GE engineer heading the development project. Hydraulics are being used because electronics cannot survive in the extreme environment inside the reactors.
“Asked if the robots are applicable to other nuclear power plants, I would say the possibility is low,” Kurosawa said, noting that the robots are designed to work amid intense radiation.
New challenges
While Hitachi-GE has built many nuclear reactors, it is encountering a variety of new challenges in developing the muscle robots simply because of the tough work required to retrieve fuel debris.
In the nuclear accident caused by the March 2011 earthquake and tsunami, cooling the fuel rods became impossible, and melted uranium fuel dropped from them. Some of the fuel broke through nuclear reactor pressure vessels and solidified as fuel debris containing uranium and plutonium.
The debris is estimated to weigh more than 800 tons in total. The insides of the PCVs at the Fukushima plant are directly exposed to the debris and are emitting radioactivity strong enough to kill a human within a few minutes.

The International Research Institute for Nuclear Decommissioning, a Tokyo-based research institute for decommissioning nuclear plants, and three reactor makers — Hitachi-GE, Toshiba and Mitsubishi Heavy Industries — have been attempting to ascertain conditions inside the reactor buildings at the Fukushima plant by means of camera- and dosimeter-equipped equipment.
https://asia.nikkei.com/Tech-Science/Science/Muscle-robots-being-developed-to-remove-debris-from-Fukushima-reactors
September 2, 2017
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Fukushima 2017 | decommissioning, Fukushima Daiichi, Robots |
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Barrier will block only a fraction of groundwater contamination

Work has begun on the final 7 meters of an “ice wall” at the Fukushima Dai-ichi nuclear power plant.
TOKYO — Tokyo Electric Power Co. Holdings began Tuesday the final phase of an underground “ice wall” around the crippled Fukushima Daiichi nuclear power plant intended to reduce groundwater contamination, though experts warn the bold project could be much less effective than once hoped.
At 9 a.m., workers began activating a refrigeration system that will create the last 7 meters of a roughly 1.5km barrier of frozen earth around the plant’s reactor buildings, which were devastated by the earthquake, tsunami and nuclear meltdowns of March 2011. Masato Kino, an official from the Ministry of Economy, Trade and Industry supervising the cleanup, spoke cautiously at the occasion, noting that “producing results is more important than the simple act of freezing” that particular segment of soil.
Tepco estimates that roughly 580 tons of water now pass through the ice wall on the reactor buildings’ landward side each day, down from some 760 tons before freezing of soil commenced in March 2016. About 130 tons daily enter the reactor buildings themselves, and Tepco hopes completing the wall will bring that figure below 100 tons.
By this math, the near-complete wall blocks only a little over 20% of groundwater coming toward it. But, as Japan’s Nuclear Regulation Authority said Aug. 15 when approving the wall’s final stage, the barrier is “ultimately only a supporting measure” to other systems preventing contamination. The main line of defense is a so-called subdrain system of 41 wells around the reactor buildings that pump up 400 to 500 tons of water daily, preventing clean water from entering the site and contaminated water from leaving it.
Slow going
Freezing of earth around the facility has been conducted gradually, amid concerns that highly contaminated water inside could rush out should the water level inside the reactor buildings drop. “Working carefully while keeping control of the water level is a must,” said Yuzuru Ito, a professor of civil and environmental engineering at Setsunan University.
It is unclear precisely when the wall will be complete. The plan is to freeze soil 30 meters deep over the course of two or three months, completing the barrier as soon as this fall. But as the gap in the wall narrows, water flows through it more quickly, making soil there more difficult to freeze. “Water is flowing quickly now, and so it is difficult to proceed as we have so far,” a Tepco representative said.
Japan has spent some 34.5 billion yen ($315 million) in taxpayer funds on the wall, expecting the icy barrier to put a decisive end to groundwater contamination at the Fukushima plant. It now appears that a dramatic improvement is not likely, though the wall will still require more than 1 billion yen per year in upkeep. “The frozen-earth barrier is a temporary measure,” said Kunio Watanabe, a professor of resource science at Mie University. “Some other type of wall should be considered as well.”
https://asia.nikkei.com/Tech-Science/Tech/Fukushima-ice-wall-facing-doubts-as-project-nears-completion
August 23, 2017
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Fukushima 2017 | Contaminated Water, Fukushima Daiichi, Ice wall |
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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 dunrenard |
Fukushima 2017 | ALPS System, Contaminated Water, Fukushima Daiichi, Leak |
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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 dunrenard |
Fukushima 2017 | Fukushima Daiichi, Nuclear Disaster, Radiotoxicity |
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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.
This 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.
A 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
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Fukushima 2017 | Fukushima Daiichi, Ice wall |
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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/

August 17, 2017
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Fukushima 2017 | Fukushima Daiichi, Ice wall |
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