A Kyoto University team has developed a new camera to visualize radioactive hotspots
Extraordinary decontamination efforts are underway in areas affected by the 2011 nuclear accidents in Japan. The creation of total radioactivity maps is essential for thorough cleanup, but the most common methods, according to Kyoto University’s Toru Tanimori, do not ‘see’ enough ground-level radiation.
“The best methods we have currently are labor intensive, and to measure surface radiation accurately,” he says, “complex analysis is needed.”
In their latest work published in Scientific Reports, Tanimori and his group explain how gamma-ray imaging spectroscopy is more versatile and robust, resulting in a clearer image.
“We constructed an Electron Tracking Compton Camera (ETCC) to detect nuclear gamma rays quantitatively. Typically this is used to study radiation from space, but we have shown that it can also measure contamination, such as at Fukushima.”
The imaging revealed what Tanimori calls “micro hot spots” around the Fukushima Daiichi Nuclear Power Plant, even in regions that had already been considered decontaminated. In fact, the cleaning in some regions appeared to be far less than what could be measured by other means.
Current methods for measuring gamma rays do not reliably pinpoint the source of the radiation. According to Tanimori, “radiation sources including distant galaxies can disrupt the measurements.”
The key to creating a clear image is taking a color image including the direction and energy of all gamma rays emitted in the vicinity.
“Quantitative imaging produces a surface radioactivity distribution that can be converted to show dosage on the ground,” says Tanimori. “The ETCC makes true images of the gamma rays based on proper geometrical optics.”
This distribution can then be used to relatively easily measure ground dosage levels, showing that most gamma rays scatter and spread in the air, putting decontamination efforts at risk.
“Our ETCC will make it easier to respond to nuclear emergencies,” continues Tanimori. “Using it, we can detect where and how radiation is being released. This will not only help decontamination, but also the eventual dismantling of nuclear reactors.”
Fury sparked in Japan as companies found duping foreign refugees into decontamination work in Fukushima
TOKYO, March 17 (Xinhua)– “Such scams are a shame to Japan,” said a reporter from Tokyo Metropolitan Television Broadcasting Corp., referring to a recently-exposed scandal involving labor dispatch agencies duping foreign refugees into doing decontamination work in Fukushima.
Various local media have exposed recently that some Japanese companies have swindled foreign refugees into doing decontamination work in Fukushima with empty promises that such work might help extend their visas to stay in Japan.
Fifty-year-old Hosein Moni and 42-year-old Hosein Deroaru from Bangladesh were both caught in such a scam, according to a recent report by the Chunichi Shimbun, one of the largest newspapers in Japan.
The two came to Japan in 2013 seeking to be recognized as political refugees. In Japan, foreigners are given temporary permission to stay for up to six months at one application before they are recognized as refugees and given status as residents.
According to government data, the number of refugees actually afforded recognition as refugees in Japan is disproportionately low among developed nations, while the numbers of those applying for refugee status has been rapidly increasing in recent years in Japan.
The government received some 5,000 such applications in 2014, but only 11 were granted refugee status, according to the data.
Moni and Deroaru were told by a so-called labor dispatch agency in Nagoya that they could do decontamination work in exchange for an extension of their visa.
The two, knowing little Japanese and trying to seize every opportunity they could, accepted the job and worked in Fukushima for three months in 2015.
But when they finished their work and went to the local immigration bureau to extend their stay, they were told by officers there that they knew nothing about such a policy.
They later found out that the construction company that had hired them had changed its company name, and its Fukushima branch had closed.
Half of the 20 workers that they had worked with in Fukushima were foreigners, many of whom had been applying for refugee status in Japan, the pair later recalled.
Their work mainly involved clearing away contaminated soil with spades, and while they were at work might well have been affected by high levels of radiation. “The radiation detectors we brought with us kept sounding alarms, which was rather scary,” they were quoted as saying.
The incident, after been exposed by local media, also caused a splash on social network sites. Many Japanese netizens felt indignant that such scams were happening in their homeland.
“Earthquake, nuclear plant, poverty… there are always some people trying to cheat or hurt other people here just for money,” remarked Kojima on Twitter.
“Why has my home country degenerated to such a low place,” said “Hootoo,” another netizen here.
They also called on the Japanese government to strengthen regulations on the Japanese companies to prevent such scams from happening.
Japan’s immigration bureau, for its part, said that the incident was with “vile nature”, and it would conduct investigations soon.
In fact, however, for a long time, due to lack of manpower, many of Japan’s “three-K” (kiken, kitanai, kitsui, which means dangerous, dirty and tiring) jobs have been done by foreign immigrants, as the Japanese are reluctant to do such work.
“As Japanese people don’t want to do the work, it has to be done by foreigners,” said Ishikawa, a Brazil-born Japanese who was in charge of coordinating foreign workers in decommissioning work linked to the Fukushima Daiichi Nuclear Plant, according to a report published by the Mainichi Shimbun last year.
Most of the foreign workers could hardly speak Japanese. As anti-radiation brochures provided by the plant’s operator, Tokyo Electric Power Company Holdings Inc. (TEPCO), were only available in Japanese or English, many of the workers could not understand it, Ishikawa was quoted as saying.
The foreign workers, to some extent, saved the contractors and TEPCO by pushing forward the decommissioning work of the nuclear plant, remarked the report.
A magnitude-9.0 earthquake in 2011 triggered a massive tsunami which destroyed the emergency power and then the cooling system of the Fukushima Daiichi nuclear power plant, and caused a serious nuclear disaster, forcing some 300,000 people to evacuate.
The operator of the crippled Fukushima Daiichi nuclear plant, has said it plans to decommission the crippled reactors in about four decades.
However, the difficult tasks such as processing contaminated water, cooling the reactors and removing nuclear fuel and debris, continue to pose serious challenges to the power company as well as the government.
Six years after it suffered a nuclear meltdown, Fukushima appears to have returned to a semblance of normalcy. But there is still a long way to go in terms of cleaning up the site. Martin Fritz reports.
A filter mask covering the mouth and nose, a headscarf, a helmet, gloves and two layers of socks – they constitute the protective gear that must be worn by any ordinary visitor to the Fukushima nuclear power station.
Only a few workers now have to wear face masks and hazmat suits, since most of the ground at the site has been sealed with concrete.
“The radiation is now as low as in the Tokyo’s Ginza shopping district,” Tokyo Electric Power Co. (TEPCO) manager Yuichi Okamura assured a group of journalists during their recent visit to the plant.
But the illusion of normality evaporates as soon as the visitors get off their bus and stand within sight of the reactors, with dosimeters indicating radiation levels of around 160 to 170 microsieverts per hour – nearly 2,000 times above what is considered safe.
“We cannot stay here for long,” warns Okamura.
On the surface, it appears that much has changed in Fukushima since the disaster struck six years ago. The clean-up work has evidently made progress.
But the sight of skeletal steel frames, torn walls and broken pipes immediately reminds one of the 17-meter-high tsunami which flooded the facility six years ago and brought its reactors to a complete standstill.
It’s expected to take 30 to 40 years to completely clean up the Fukushima Daiichi plant, which was hit by the world’s worst nuclear disaster since Chernobyl following a magnitude-9 earthquake and the subsequent tsunami. The operation is likely to carry a hefty price tag, with Japanese officials recently estimating it to cost around $189 billion in total.
Today, with 6,000 workers employed, the nuclear power plant is Japan’s largest and most expensive construction site – and it will remain so for decades. “We’re struggling with four problems,” says TEPCO manager Okamura: “Reducing the radiation at the site, stopping the influx of groundwater, retrieving the spent fuel rods and removing the molten nuclear fuel.”
Black lumps in the reactor containment
Progress in these areas, however, is slow. For instance, workers are erecting scaffolding around the collapsed roof of reactor No 1, but it will likely take four more years for the debris there to be cleared away. Only then can the almost 400 old fuel rods be retrieved from the reactor’s holding basin.
In the adjacent reactor No 2, the blue exterior still remains intact. Workers in hazmat suits can be seen walking on a new metal platform halfway up the reactor building. But behind the wall lies a nuclear nightmare. A robot sent into the reactor in January found highly dangerous black lumps of leaked fuel on a platform in the outer reactor containment.
“There is now fatally high radiation in that part,” says Okamura.
The engineer quickly turns to reactor No 3, where the progress is more obvious. A hydrogen explosion had turned the reactor’s roof into a tangle of bent metal. It took years of work to dismantle this steel scrap and remove the rubble. “Now we’re building a new roof with an integrated hoisting crane,” says Okamura proudly.
“From next year, we would finally be able to close in on the nearly 600 burnt fuel rods,” he noted. But unlike in reactor No 4, the clean-up must be undertaken remotely as the radiation is so strong that people can only stay there for a few minutes. As a result, the construction of the lifting device has already been delayed by several years.
The situation at the reactors raises doubts about the optimism shared by Japanese officials with regard to the orderly decommissioning of the plant. At the next stop, Okamura shows the control center of the underground ice wall that was built to prevent groundwater from leaking into the reactor basements and mixing with radioactive coolant water.
Since its construction, it has managed to reduce the amount of groundwater flowing into the reactor basements. But five sections of the wall have had to be kept open to prevent water inside the reactor basements from rising and flowing out too rapidly.
Despite all these adversities, the Japanese government and TEPCO are planning to decide as early as this summer how to remove the molten nuclear fuel from the reactors.
Even Shunji Uchida, the Fukushima Daiichi plant manager, couldn’t hide his skepticism from the visiting journalists. “Robots and cameras have already provided us with valuable pictures,” says Uchida, adding: “But it is still unclear what is really going on inside.”
FUKUSHIMA — With six years having passed since the onset of the nuclear disaster at Tokyo Electric Power Co. (TEPCO)’s Fukushima No. 1 nuclear plant, the government’s decontamination plan in this prefecture is fast approaching the end of its first phase at the end of March.
As a consequence of the decontamination project — and the fact that radioactive material decays over time — radiation levels in Fukushima Prefecture have declined to some extent.
However, in certain areas of the prefecture, radiation levels continue to be high, and the issue of what to do with decontamination waste still needs to be tackled. The government does plan to carry out decontamination work in the neglected “difficult-to-return” evacuation zones in fiscal 2017, but local residents are skeptical that the end is near.
To date, the Environment Ministry has carried out decontamination work in 11 municipalities across the prefecture subject to evacuation orders. However, no decontamination has been done yet in the “difficult-to-return” zones. In other municipalities, where the radiation dose is 0.23 microsieverts per hour or higher, decontamination work has been performed by the relevant local government office.
Initially, the central government-led decontamination was supposed to finish in March 2014, but this was pushed back to March 2017, owing to delays related to makeshift storage sites for contaminated soil. The Environment Ministry plans to finish its decontamination work by the end of March 2017, after which it plans to move the contaminated soil to interim storage facilities.
In areas where the central government is in charge of decontamination, “follow-up” decontamination will also take place in the event that radiation levels do not drop enough, in the hope that residents will eventually be able to return home. Conversely, there will be no follow-up in cases where decontamination is being handled by a local authority, making local residents anxious.
Nevertheless, there are a few spots where follow-up decontamination has taken place in addition to the work in the 11 municipalities overseen by the government. There are nine such spots in total, and they are all in the city of Soma. The Soma Municipal Government initially intended to conduct decontamination in about 30 locations across the city, but this was eventually reduced to nine locations, owing to radiation level-related criteria for follow-up decontamination as instructed by the Environment Ministry.
A Soma Municipal Government representative stated, “Radiation levels are particularly high in forests here, and it is unknown what the future impact of this might be. I want to have a system set up whereby decontamination can be easily conducted again in the future, as necessary.” (By Hanayo Kuno, Science & Environment News Department, Kazuhisa Soneda, Fukushima Bureau, Makoto Ogawa, News Layout Center, and Yohei Kanno, Visual Group)
Two Bangladeshi asylum seekers in Japan cleared up radioactive contamination from one of the world’s worst nuclear disasters on the false promise doing so would win them permission to stay in the country longer, media reported yesterday.
The Fukushima nuclear plant suffered multiple meltdowns after being hit by a tsunami triggered by a big earthquake on March 11, 2011. Companies decontaminating areas around the plant, which usually involves removing radioactive top soil, have struggled to find workers willing to do the job.
The two men, who arrived in Japan in 2013 saying they were escaping political persecution, said they were told by brokers and construction companies that their visas would be extended if they did decontamination work, the Chunichi newspaper reported.
“We believed the visa story because they said it’s a job Japanese people don’t want to do,” Chunichi quoted one of the men, Monir Hossain, as saying.
Reuters was not able to reach the two men.
The men did the decontamination work in Iitate village, about 50 km (30 miles) south of the plant, from January to March 2015, Chunichi said.
Japan maintains tight controls on the entry of foreign workers but asylum seekers are allowed to work while their applications are reviewed. Many have permits allowing them to stay and work that have to be renewed every six months.
Mitsushi Uragami, a justice ministry official who oversees refugee recognition, said there were no residence permits on offer for people doing decontamination.
“The length of asylum seekers’ residence permits and them doing decontamination work are unrelated. If anyone is giving inaccurate explanations about this, it’s problematic,” Uragami told Reuters.
The department was investigating the case, he said.
Takuya Nomoto, an environment ministry official overseeing decontamination, said the Chunichi report did not give the names of the companies or labour brokers involved, and as such the ministry was not able to confirm it.
“The ministry expects all contractors involved in decontamination to comply with the law,” he said.
The Fukushima Labour Bureau said this month more than half of the 1,020 companies involved in decontamination violated labour and safety laws last year.
Reuters revealed in 2013 that homeless men were put to work clearing radioactive soil and debris in Fukushima for less than the minimum wage.
Reuters also found the clean-up depended on a little scrutinised network of subcontractors – many of them inexperienced with nuclear work and some with ties to organised crime.
Masaaki Sakai faces his home, which remains standing in the Fukushima Prefecture village of Iitate, on Feb. 15, 2017. In some spots the level of radiation exceeds 1 microsievert per hour, and Sakai has decided to have the structure demolished. (Mainichi)
FUKUSHIMA — As decontamination planned in the wake of the Fukushima nuclear disaster nears an end this fiscal year, focus is shifting to the massive amount of radioactively tainted soil that has piled up during decontamination work. But the construction of interim storage facilities that are supposed to hold this waste within Fukushima Prefecture for up to 30 years before it is finally disposed of has been delayed.
As of the end of February, only about 20 percent of the 16,000 hectares earmarked for interim storage has been acquired through land contracts. It thus appears inevitable that provisional and onsite storage that was only supposed to last for three years will drag on for a long time. The situation casts doubt on the prospects of finding a final resting place for the waste outside Fukushima Prefecture within 30 years.
Six years after the disaster at the Fukushima No. 1 Nuclear Power Plant, the Fukushima Prefecture village of Iitate remains completely evacuated. With the exception of a so-called “difficult to return zone” in the south of the village, the central government plans to lift the evacuation order upon completion of decontamination work at the end of March.
Masaaki Sakai, 39, who now resides in the city of Fukushima, has a home in the Komiya district of Iitate, right next to the village’s “difficult to return” zone. A dosimeter during a recent visit showed the area around the 60-year-old, snow-covered farmhouse stood at more than 1 microsievert per hour. The level equates to more than 5 millisieverts per year — five times the 1 millisievert exposure limit for a regular person.
Sakai points out that level of radiation is sometimes higher. “Today the level is low because there is snow,” he says. In the near future he plans to have his home pulled down, as the deadline for applying for the government to cover the cost of doing so is approaching.
“Even if I want to return to Iitate, if they say, ‘Decide now’ then the only thing I can do is decide not to return,” he murmurs.
One of the reasons behind Sakai’s decision not to return is the radioactively contaminated soil that remains in the village. Walking around the village, one can see mounds with green covers over them, concealing flexible containers that hold contaminated soil. According to the Ministry of the Environment, the amount of tainted soil stored temporarily like this, as of the end of January, totals roughly 2.4 million cubic meters for the village of Iitate alone, or enough to fill the Tokyo Dome baseball stadium twice.
So far, however, only about 6,000 cubic meters of soil have been transported to interim storage facilities, while the amount due to be transported next fiscal year stands at about 22,000 cubic meters. At this pace, under a simple calculation, it would take over 100 years to transport all of the waste to interim storage facilities.
“There’s no way I’m going to live surrounded by mountains of contaminated soil,” Sakai says.
Makeshift storage of radioactive soil in areas that have not been evacuated also looks likely to be prolonged. In areas that aren’t under evacuation orders, it is the local municipalities, not the government, that handle the decontamination work. In five municipalities including the cities of Fukushima and Koriyama, the contaminated soil left after decontamination work is mostly buried onsite.
Six years have passed since the outbreak of the Fukushima nuclear disaster, and in many cases people have asked for the waste to be removed so they can extend or rebuild their homes or resume farming activities, but the delay in building interim storage facilities means the only solution for the time being is to change the spot where the waste is buried.
It costs several hundred thousand yen to rebury waste in a single case, but until now the Ministry of the Environment has not allowed funds to be used for the reburying of such waste, on the premise that it is supposed to be stored for only a short period of time. Local bodies have still billed the central government by quietly tacking on the cost to the fee for other decontamination work, but this will become more difficult to do next fiscal year when decontamination work is completed.
In January, the Ministry of the Environment adopted a new policy of granting funds for the reburying of waste if the original location hindered the construction of a new home. An official at one local body commented that the move was a relief, but there are outstanding issues. As a rule, the government collectively bills Tokyo Electric Power Co. (TEPCO), operator of the Fukushima No. 1 Nuclear Power Plant, for the cost of decontamination work, but it is unclear whether TEPCO has to pay for the reburial of tainted soil.
Separately, decontamination work has also been carried out in prefectures besides Fukushima — extending to 57 municipalities in seven prefectures, including Tochigi and Miyagi. The amount of contaminated soil in these cases stands at about 320,000 cubic meters. In about 95 percent of cases, the soil is stored onsite. But since interim storage facilities are designed for contaminated soil from Fukushima Prefecture alone, it has not even been decided what should be done with this waste.
Decontamination work is conducted on March 2 in Namie, Fukushima Prefecture, which will no longer be designated an evacuation zone on March 31.
Half of Fukushima Prefecture residents believe it will take at least another 20 years for them to return to the lives they enjoyed before the 3/11 disaster, according to a new poll.
The Asahi Shimbun and Fukushima Broadcasting Co. contacted prefectural residents on Feb. 25-26 to ask about life after the triple nuclear meltdown crisis following the 2011 Great East Japan Earthquake and tsunami. It was the seventh in the annual series of polls on the issue.
In the survey, 50 percent of respondents said “more than 20 years” when asked their outlook on the timescale to restore their previous lifestyle. Twenty-one percent said “about 20 years,” followed by 16 percent who thought “about 10 years,” and 7 percent who responded “about five years.”
In the 2013 poll, those who thought it would take more than two decades for them to regain their pre-disaster life totaled 60 percent. The numbers cannot simply be cross-referenced since 18 and 19 years olds have been included in the latest survey for the first time, but while the results suggest some improvement, they also paint a picture of many residents of the prefecture still unable to have an optimistic outlook on their future.
Thirty percent of respondents of the latest survey said there are times they feel discriminated against for being Fukushima Prefecture residents.
The central government plans to cover part of the costs on the Fukushima nuclear crisis that is estimated to rise to 21.5 trillion yen ($188 billion) by including the expenses in electricity rates on regular households.
It is a plan that has been criticized to be nothing more than a scheme to bail out Tokyo Electric Power Co., operator of the Fukushima No. 1 nuclear power plant, and 76 percent of respondents said they could not accept such a measure.
With the evacuation order for the town of Tomioka scheduled to be lifted on April 1, most residents of the prefecture who were displaced from their homes due to the nuclear disaster will be able to go back, excluding those who lived in areas still designated as “difficult-to-return zones.”
But opinions over the issue varied among respondents, suggesting skepticism over decontamination work and concerns over radiation still linger among many residents.
When asked about the timing of lifting the evacuation order, the most popular answer, from 40 percent, was that it was an appropriate decision. However, 19 percent said it was “too soon,” while 22 percent said the order “should not be lifted in the first place.” Nine percent said it was “too late.”
Respondents were also divided over their evaluation of decontamination work in the prefecture conducted by the central and local governments.
Those who applauded the effort, which comprised the 3 percent who “highly” praised it and the 48 percent who “somewhat” did, was at just over half. But an almost equal amount of respondents, 46 percent, expressed criticism, with 39 percent saying they “did not really” think enough was being done and 7 percent saying they were not at all satisfied.
When asked whether they had any concerns of the effects of radiation on themselves or their family, most residents, at 63 percent, said yes. This comprised the 19 percent who said they were very concerned and the 44 percent who responded they were worried to some extent.
Those who were more critical of the decontamination efforts, as well as respondents who expressed concern over the effects of radiation, tended to reply that the evacuation order “should not be lifted in the first place.”
Regarding “difficult-to-return zones,” the central government plans to concentrate their decontamination work on specific areas to allow residents to live there.
Respondents were divided over this decision as well, with 43 percent for and 42 percent against.
However, when asked about how the central government and TEPCO were handling the buildup of contaminated groundwater at the crippled nuclear plant, the majority of respondents expressed criticism. A total of 71 percent said they were dissatisfied, compared with the 14 percent who thought enough was being done.
The poll targeted eligible voters aged 18 or older living in the prefecture. Valid responses were received from 934 individuals out of the 1,739 randomly generated landline numbers contacted, or 54 percent.
Bribery scandal over Fukushima decontamination
Police in Japan have arrested an environment ministry official for alleged bribery over decontamination work following the Fukushima Daiichi nuclear disaster.
Fifty-six-year-old Yuji Suzuki, who works at a ministry sub-branch in the prefecture, is suspected of helping a construction company land such work in exchange for wining and dining.
The work is aimed at removing radioactive material from houses, soil and woods near the crippled plant.
Fukushima and Tokyo police found that Suzuki was provided entertainment at hostess bars and a free trip worth about 1,750 US dollars from the construction firm in Toyama Prefecture.
Police also arrested a former president of the firm, Mikio Kosugi over the suspected bribery. The 2 have reportedly admitted to the allegations.
Suzuki is among experts hired on a temporary basis by the ministry to deal with reconstruction work including cleaning up widespread fallout from the accident. Police say he was in charge of overseeing decontamination.
Environment Minister Koichi Yamamoto on Thursday expressed regret, saying the scandal could undermine Fukushima people’s trust in the cleanup effort.
He said his ministry will try to win back public trust by tightening discipline and carrying out work properly.
Bureaucrat held for allegedly taking bribe for Fukushima cleanup work
TOKYO (Kyodo) — Police arrested an Environment Ministry employee Thursday on suspicion of receiving a bribe in exchange for favorable treatment in the allocation of cleanup work in Fukushima Prefecture following the 2011 nuclear disaster.
The police alleged that Yuji Suzuki, 56, who handles radiation decontamination work at a local branch of the ministry, was offered nightclub entertainment several times over a period between 2015 and 2016 by a former company manager, the police said.
The police also arrested Mikio Kosugi, 63, for allegedly wining and dining Suzuki in hopes of getting the public servant to give his Toyama Prefecture company work to remove radioactive materials from near the crippled Fukushima Daiichi plant, the police said.
Both Suzuki and Kosugi admitted the allegation, according to police. Sources close to the matter said the estimated value of the inducements Suzuki received is several hundred thousand yen.
The allegation surfaced as the Ministry of Economy, Trade and Industry has estimated the cost of decontamination work, including soil and tree removals, will surge to 4 trillion yen ($35 billion) from an earlier projection of 2.5 trillion yen.
Doped carbon could partially treat contaminated water from Fukushima Daiichi removing nearly 93 percent of cesium and 92 percent of strontium in a single pass
Nothing new here. There are lots of ways of pulling radionuclides out of water : activated carbon, ion exchange, chemical affinity, sunflowers (phytoremediation). But still can’t deal with tritium. All costs money, and results in just shifting the contamination to a different material. Radionuclides cannot be simply destroyed, they can only be shifted from one location/ source to another.
Doped carbon could treat water from Fukushima
US and Russian scientists have discovered a new way to remove radioactivity from water, which could be used to treat contaminated water at Japan’s Fukushima nuclear plant.
The researchers, from Rice University and Kazan Federal University, used oxidatively modified carbon (OMC) material to remove caesium and strontium from samples of water. Published in the journal Carbon, their work details how over 90 per cent of the radioactive elements were extracted using OMC column filtration.
“Just passing contaminated water through OMC filters will extract the radioactive elements and permit safe discharge to the ocean,” said Rice chemist James Tour, who led the project with Ayrat Dimiev, a former postdoctoral researcher in his lab and fuknow a research professor at Kazan Federal University. “This could be a major advance for the cleanup effort at Fukushima.”
According to Tour, OMC makes good use of the porous nature of two specific sources of carbon. One is an inexpensive, coke-derived powder known as C-seal F, used by the oil industry as an additive to drilling fluids. The other is a naturally occurring, carbon-heavy mineral called shungite, which is found mainly in Russia.
The team found that the two types of OMC were efficient at extracting cesium, which has been the hardest element to remove from radioactive water stored at Fukushima. The OMC was also much easier and less expensive than previously used filtration materials such as graphene oxide.
“We know we can use graphene oxide to trap the light radioactive elements of relevance to the Fukushima cleanup, namely caesium and strontium,” Tour said. “We learned we can move from graphene oxide, which remains more expensive and harder to make, to really cheap oxidised coke and related carbons to trap these elements.”
As well as being cheaper than other materials, OMC has the added advantage of not having to be stored alongside the radioactive waste it is used to treat.
“Carbon that has captured the elements can be burned in a nuclear incinerator, leaving only a very small amount of radioactive ash that’s much easier to store,” said Tour.
Treated carbon pulls radioactive elements from water
Researchers at Rice, Kazan universities develop unique sorbents, target Fukushima accident site
Researchers at Rice University and Kazan Federal University in Russia have found a way to extract radioactivity from water and said their discovery could help purify the hundreds of millions of gallons of contaminated water stored after the Fukushima nuclear plant accident.
They reported that their oxidatively modified carbon (OMC) material is inexpensive and highly efficient at absorbing radioactive metal cations, including cesium and strontium, toxic elements released into the environment when the Fukushima plant melted down after an earthquake and tsunami in March 2011.
C-seal F, a source used to synthesize oxidatively modified carbon, is seen magnified 20 times by a scanning electron microscope. The material is highly effective at removing radionuclides from water, according to researchers at Rice University and Kazan Federal University. Click on image for a larger version. Courtesy of Kazan Federal University
OMC can easily trap common radioactive elements found in water floods from oil extraction, such as uranium, thorium and radium, said Rice chemist James Tour, who led the project with Ayrat Dimiev, a former postdoctoral researcher in his lab and now a research professor at Kazan Federal University.
The material makes good use of the porous nature of two specific sources of carbon, Tour said. One is an inexpensive, coke-derived powder known as C-seal F, used by the oil industry as an additive to drilling fluids. The other is a naturally occurring, carbon-heavy mineral called shungite found mainly in Russia.
The results appear this month in Carbon.
Tour and researchers at Lomonosov Moscow State University had already demonstrated a method to remove radionuclides from water using graphene oxide as a sorbent, as reported in Solvent Extraction and Ion Exchange late last year, but the new research suggests OMC is easier and far less expensive to process.
Treating the carbon particles with oxidizing chemicals increased their surface areas and “decorated” them with the oxygen molecules needed to adsorb the toxic metals. The particles were between 10 and 80 microns wide.
While graphene oxide excelled at removing strontium, Tour said, the two types of OMC were better at extracting cesium, which he said has been the hardest element to remove from water stored at Fukushima. The OMC was also much easier and less expensive to synthesize and to use in a standard filtration system, he said.
“We know we can use graphene oxide to trap the light radioactive elements of relevance to the Fukushima cleanup, namely cesium and strontium,” Tour said. “But in the second study, we learned we can move from graphene oxide, which remains more expensive and harder to make, to really cheap oxidized coke and related carbons to trap these elements.”
While other materials used for remediation of radioactive waste need to be stored with the waste they capture, carbon presents a distinct advantage, he said. “Carbon that has captured the elements can be burned in a nuclear incinerator, leaving only a very small amount of radioactive ash that’s much easier to store,” Tour said.
C-seal F, a carbon source, magnified 200 times reveals its high surface area of 12.5 square meters per grams. Processing it into oxidatively modified carbon raises its surface area to 16.9 square meters per gram while enhancing its ability to remove radioactive cesium and strontium from water, according to researchers at Rice University and Kazan Federal University. Click on image for a larger version. Courtesy of Kazan Federal University
“Just passing contaminated water through OMC filters will extract the radioactive elements and permit safe discharge to the ocean,” he said. “This could be a major advance for the cleanup effort at Fukushima.”
The two flavors of OMC particles – one from coke-derived carbon and the other from shungite — look like balls of crumpled paper, or roses with highly irregular petals. The researchers tested them by mixing the sorbents with contaminated water as well as through column filtration, a standard process in which fluid is pumped or pulled by gravity through a filter to remove contaminants.
In the mixing test, the labs dispersed nonradioactive isotopes of strontium and cesium in spring water, added OMC and stirred for two hours. After filtering out the sorbent, they measured the particles left in the water.
OMC1 (from coke) proved best at removing both cesium and strontium from contaminated water, getting significantly better as the sorbent was increased. A maximum 800 milligrams of OMC1 removed about 83 percent of cesium and 68 percent of strontium from 100 milliliters of water, they reported.
OMC2 (from shungite) in the same concentrations adsorbed 70 percent of cesium and 47 percent of strontium.
The researchers were surprised to see that plain shungite particles extracted almost as much cesium as its oxidized counterpart. “Interestingly, plain shungite was used by local people for water purification from ancient times,” Dimiev said. “But we have increased its efficiency many times, as well as revealed the factors behind its effectiveness.”
In column filtration tests, which involved flowing 1,400 milliliters of contaminated water through an OMC filter in 100-milliliter amounts, the filter removed nearly 93 percent of cesium and 92 percent of strontium in a single pass. The researchers were able to contain and isolate contaminants trapped in the filter material.
Co-authors of the paper are Artur Khannanov, Vadim Nekljudov, Bulat Gareev and Airat Kiiamov, all of Kazan Federal University. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice. The Russian Government Program of Competitive Growth of Kazan Federal University supported the research.
In Yamada, Futaba District, Fukushima, trucks carrying waste after decontamination work, go by spreading unmeasurable amount of radiation.
The Geiger counter hits 9.99 microSv/h which is its limit!
Recovery effort? Is n’t it better to relocate the entire residents elsewhere safe? In Japan, there are many villages and small towns where they suffer with depopulation.
What they do now is just to keep feeding big contractors, not helping affected people…..
Source: Oz Yo
Certificates of training in radioactive decontamination work were issued by a company in Nihonmatsu, Fukushima Prefecture, to workers who had received no such training.
NIHONMATSU, Fukushima Prefecture–A company has admitted to not giving the required special training to workers before dispatching them to carry out decontamination work in radiation-hit Fukushima city.
A subcontractor called “Zerutech Tohoku” issued at least 100 bogus certificates to its workers showing they had completed the training, when, in fact, they had done nothing, according to the Fukushima Labor Standards Inspection Office.
The office had warned the subcontractor, which is based in Nihonmatsu and decontaminates parts of nearby Fukushima city, which was affected by the 2011 nuclear disaster, that it should give special training to workers to prepare them for the task.
The Ministry of Health, Labor and Welfare requires decontamination operators be given at least 5.5 hours of special training to each individual in accordance with the Industrial Safety and Health Law.
The training includes a lecture on potential health hazards and how to operate decontamination equipment as their job involves handling soil polluted by radioactive materials.
The 52-year-old representative of the company admitted wrongdoing in an interview with The Asahi Shimbun.
“We had to hire a large number of workers over a short period of time since we received a contract involving a vast swath of land,” he said of the false certificates, of which between 100 and 150 have been discovered.
In addition, the company, a fourth-tier subcontractor, issued seven other kinds of certificates needed to operate an aerial vehicle or chain saw, which were required to land the cleanup contract.
For issuing false certificates, offenders could be imprisoned for up to six months or fined 500,000 yen ($4,800).
But the law has been criticized for having numerous loopholes.
One is that there is not test of workers’ knowledge after they have received the training.
The operators are also not required to register the certificates with municipal authorities.
And it is not specified what qualifications are required for the person who conducts the training.
The Labor Standards office, a regional arm of the health ministry, has been inspecting the company for breaches of the law and regulations on decontamination work since Oct. 19.
The Zerutech Tohoku representative founded the company in March last year.
In Fukushima Prefecture, large quantities of contaminated soil and waste have been generated from decontamination activities. Currently, it is difficult to clarify methods of final disposal of such soil and waste. Until final disposal becomes available, it is necessary to establish an Interim Storage Facility (ISF) in order to manage and store soil and waste safely.
The only solution proposed is a storage facility of 16 km2 around the Fukushima plant for a period of 30 years. After that, time will tell, because the problems are endless.
The following materials generated in Fukushima Prefecture will be stored in the ISF.
1. Soil and waste (such as fallen leaves and branches) generated from decontamination activities, which have been stored at the Temporary Storage Sites.
2. Incineration ash with radioactive concentration more than 100,000 Bq/kg.
It is estimated that generated soil from decontamination will be approx. 16 ~22 mil. m3 after the volume reduction incineration, estimated value based on the decontamination implementation plan of July 2013. (Ref: approximately 13~18 times as much as the volume of Tokyo Dome (1.24 mil. m3) .
Transportation to Stock Yards
In order to confirm safe and secure delivery towards the transportation of a large amount of decontamination soil, MOE implemented the transportation approx. 1,000m3 each from 43 municipalities in Fukushima Prefecture from 2015-2016.
Actual achievement in 2016 as of July 30, 2016
Stored volume: 13,384m3 (58,766m3 in total)
Stock yards in Okuma: 4,883m3; stock yards in Futaba: 8,501m3
* Calculated on the assumption that the volume of a large bag is 1m3
Total number of trucks used: 2,279 (9,808 in total)
Stock yards in Okuma: 815 trucks; stock yards in Futaba:1,464 trucks
To construct facilities, it will need comprehensive area and 2/3 will be assumed to be used for facilitation. The possible volume for installation is to be 10,000m3/ha and 140,000m3/5ha for a storage facility, and will be installed from TSS to ISF sequentially.
Approximate period from contract with operators to ISF operation: 3months for TSS, 6months for delivery & classification, 12months for storage, 18months for incineration.
On the premise that infrastructure construction on roads for Okuma and Futaba IC would proceed as planned, the maximum volume of possible transportation is estimated: 2millions m3 /y before the operation of both IC, 4millions m3/y after Okuma IC & before Futaba IC, 6 millions m3/y after the both ICs operation.
Landowners are still reluctant to sell their land to put the waste. In late September 2016, according to the official data of the Ministry of Environment, only 379 owners out of 2360 had signed a contract. This represents an area of 144 ha, or about 9% of the total project.
The town of Okuma, is almost entirely classified as “difficult to return”zone, therefore it intends to offer all its municipal land to put the waste. This represents 95 hectares, or about 10% of land considered in the town. This includes schools, the Fureai Park with some sports grounds … The town has not yet decided whether it would sell or would lease its land.
Meanwhile, it is an abandoned village:
The Joban railway line was partially destroyed by the tsunami, as here in Tomioka:
Destroyed Tomioka train station and sorting facility for radioactive waste
Some parts have reopened, but not in the most contaminated areas; between Tatsuta and Namie. Japan Railway wants to fully reopen the railway before 2020, avoiding the coast. Decontamination should produce 300,000 m3 of radioactive waste. The radioactive waste bags are along the railway, but they will need to be take them away. The Environment Ministry is negotiating with landowners owning the land beside the railway, but this is not enough because few responded favorably. So it’s a game of musical chairs that is planned: use the lands where some waste is right now after they’ll freed by the transfer of the waste to the storage center located around the Fukushima Dai-ichi.
Meanwhile, the waste is piling up everywhere:
Radioactive waste in Iitate
Valley of radioactive waste in Iitate mura
This storage was not expected to last as long, which is not without causing problems because the bags do not hold. Here in Tomioka, weeds grow back:
The equivalent of the Court of Accounts of Japan went to inspect some of these sites and found other problems, according to the Asahi. Those who receive contaminated soil, are elevated in the center so that the water flows over the edges where it can be harvested and controlled because the bags are not waterproof. There are up to 5 levels. With time and the weight of waste, a hollow that may appear in the center, and contaminated water accumulates there. Monitoring is difficult or impossible. See diagram of Asahi:
It is not normal that the Nuclear Regulatory Authority, the NRA does not control these storage sites for radioactive waste.
Regarding the waste from the decommissioning of nuclear power plants, the NRA wants to bury the most contaminated within 70 meters for 100 000 years. This is essentially reactor control rods. Utilities would bear responsibility for 300 to 400 years. They have not yet found where to have the sites … Read Asahi for more. http://www.asahi.com/ajw/articles/AJ201609020034.html
The government relies on the radioactive decay for these wastes to pass below the 8000 Bq / kg to be downgraded and utilized …
The Mainichi Shimbun answers some common questions readers may have about the decontamination of areas that were heavily exposed to radiation in the nuclear crisis at the Fukushima No. 1 Nuclear Power Plant.
Question: What is the situation right now with the decontamination of areas that were exposed to radioactive materials in the Fukushima nuclear incident, where residents were ordered to evacuate?
Answer: In April 2012, areas that were under evacuation orders were separated into three categories based on annual radiation exposure dosages. Decontamination work has not been carried out in areas of the Fukushima Prefecture towns of Okuma, Futaba, Namie, Tomioka, and the prefectural villages of Iitate and Katsurao and the city of Minamisoma — classified as “difficult-to-return zones” with annual radiation exposure dosages topping 50 millisieverts — save for a few areas that were decontaminated on a trial basis.
Meanwhile, in “restricted residence zones,” where the annual radiation exposure dosage is between 20 and 50 millisieverts, and in “preparing for lifting of evacuation order zones,” which have annual radiation exposure dosages of 20 millisieverts or lower, the government is aiming to have decontamination completed by March 2017.
Q: Why haven’t “difficult-to-return zones” been decontaminated?
A: In addition to the fact that all residents had evacuated, it was determined immediately after the disaster broke out that decontamination efforts would be ineffective because of the high levels of radiation there. However, radiation has the property of decreasing as time passes. Indeed, according to measurements taken by an airplane that was released by the Nuclear Regulation Authority in February this year, radiation levels had gone down significantly. And in some areas, where decontamination was attempted on a trial basis, there was some success.
Q: How much does radiation go down through the decontamination process?
A: According to the Environment Ministry, in a trial decontamination of the Akougi district in Namie, Fukushima Prefecture — designated a “difficult-to-return zone” — radiation levels went down by half. However, a ministry official explains that radiation levels there cannot be brought down to zero because even if the area is decontaminated, radiation seeps in via rain and other means.
Q: What is done with the waste that results from decontamination?
A: The Environment Ministry estimates that 16 million to 22 million cubic meters of radioactively contaminated waste will result from decontamination work. That waste will be stored temporarily in municipalities in Fukushima Prefecture, then transported to interim storage facilities in the prefectural towns of Okuma and Futaba. However, only 5 percent of the entire land area needed for storing radioactive waste had been secured as of late July. (Answers by Hanayo Kuno, Science and Environment News Department)
Meanwhile, problems still persist at the nuclear plant, most notably with the ‘highly contaminated’ water being stored in tanks at the site
That includes costs for radioactive decontamination and compensation payments, the Japan Times reported.
The public cost of cleaning up the 2011 Fukushima Daiichi nuclear plant disaster topped ¥4.2 trillion (roughly $628 billion) as of March, and is expected to keep climbing, the Japan Times reported on Sunday.
That includes costs for radioactive decontamination and compensation payments. Tokyo Electric Power Company (TEPCO) will sell off its shares to eventually pay back the cost of decontamination and waste disposal, but the Environment Ministry expects that the overall price of those activities could exceed what TEPCO would get for its shares.
Meanwhile, the taxpayer burden is expected to increase and TEPCO is asking for additional help from the government.
The Times reports:
The government estimates the proceeds from TEPCO share sale at ¥2.5 trillion, but to generate the estimated gain, the TEPCO stock price needs to trade at around ¥1,050, up sharply from current market levels of some ¥360.
In addition, the Environment Ministry expects that the cumulative total of decontamination and related costs could surpass the estimated share proceeds by the March 2017 end of the current fiscal year.
[….] TEPCO and six other power utilities charged their customers at least ¥327 billion in electricity rate hikes after Japan’s worst-ever nuclear accident. Moreover, consumers paid ¥219.3 billion or more for TEPCO, chiefly to finance the maintenance of equipment to clean up radioactive water at the plant and the operation of call centers to deal with inquiries about compensation payments.
Moreover, as Deutsche Welle noted on Monday, problems still persist at the nuclear plant, most notably with the “highly contaminated” water being stored in tanks at the site.
“There are numerous problems that are all interconnected, but one of the biggest that we are facing at the moment is the highly contaminated water that is being stored in huge steel tanks at the site,” Aileen Mioko-Smith, an anti-nuclear activist with the group Green Action Japan, told DW. “They are running out of space at the site to put these tanks, the water that is being generated on a daily basis means they have to keep constructing more, and the ones that are not welded have a history of leaking.”
“The situation with contaminated water at the site is a ticking time bomb and they don’t seem to know what they can do—other than to construct more tanks,” she said.
Tokyo, Aug. 17 (Jiji Press)–Reconstruction footholds should be set up in the no-go zone heavily contaminated by the 2011 nuclear accident in Fukushima Prefecture in northeastern Japan, a Liberal Democratic Party team proposed Wednesday.
The footholds should be used for decontamination work and infrastructure development so that evacuation orders for residents of the zone will be lifted in around five years, said the ruling party’s Headquarters for Accelerating Reconstruction after the Great East Japan Earthquake.
At a general meeting, the headquarters broadly agreed on a draft outline of the party’s planned sixth reconstruction proposal for areas damaged by the March 2011 earthquake and tsunami and the subsequent reactor meltdowns at Tokyo Electric Power Company Holdings Inc.’s Fukushima No. 1 nuclear power plant.
The government plans to remove all evacuation advisories in municipalities affected by the nuclear accident by the end of March 2017, excluding in the no-go zone where radiation levels are still too high for local residents to return home anytime soon.
The LDP will submit the proposal to Prime Minister Shinzo Abe later this month, after finalizing it through discussions with its coalition partner, Komeito.
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