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Japan undecided on what to do with 1 million tonnes of radioactive water at Fukushima plant

February 2, 2018
Key points:
The rate of contaminated water reaching the facility has slowed, but is still increasing
There are now more than 1,000 tanks of contaminated water at the site
One controversial option for dealing with the water includes decontaminating it as much as possible and then gradually releasing it into the ocean
 
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Storage tanks for contaminated water at Fukushima nuclear plant
The water is being stored in hundreds of large and densely packed tanks at the plant.
 
Japanese Government officials have not figured out what to do with more than 1 million tonnes of radioactive water sitting at the site of the crippled Fukushima nuclear power plant.
Just days shy of the seventh anniversary of the nuclear disaster, Tokyo Electric Power Company (TEPCO) revealed it successfully slowed the rate of contaminated water reaching the reactor facilities, but the amount was still increasing.
“A few years a go [the radioactive water was increasing by] 400 tonnes per day, but the increase per day has now gone down to around 100 tonnes per day,” said Naohiro Masuda, TEPCO’s chief decommissioning officer.
“A few years ago we had to create one new tank every two or three days but now we need to increase one new tank every seven to 10 days, so in that sense we think it is progress, to a certain degree, in the sense it is a more stabilised situation,” he said.
There are more than 1,000 tanks of contaminated water now at the site — and Government authorities have still not decided what to do with the water.
 
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Aerial view of tanks of contaminated water at the Fukushima nuclear plant
Experts want a gradual release, but if the tanks break the water would slosh out.
 
Ice wall of limited effect
TEPCO revealed earlier this week that its underground frozen soil wall — what was expected to be the main defence against groundwater contamination — had only had a limited effect.
The 1.5-kilometre-long barrier is designed to keep groundwater from flowing into reactor buildings that were damaged by the disaster.
The wall cost more than $US300 million to build and costs $US10 million to operate.
Mr Masuda said it was important to note that the combination of the company’s measures to prevent contamination meant that the situation was less volatile overall.
So while the level of contaminated water is still increasing — albeit at a slower rate — the Japanese Government is yet to agree on what to do with it.
One controversial option includes decontaminating the water as much as possible and then gradually release it into the ocean.
Experts advising the Government have urged a gradual release of the water to the nearby Pacific Ocean.
Treatment can remove all the radioactive elements except tritium, which they say is safe in small amounts.
But local fishermen have balked at the idea, fearing a devastating impact to the reputation of their produce.
Satoru Toyomoto from the Japanese Ministry of Economy, Trade and Industry said a Government sub-committee was still considering its options.
“You may think after as many as seven years [this should be decided], but we have done our utmost and we have done all possible things and we have finally come to a stage where we can consider this,” he said.
“After the accident occurred [in 2011] it was like a field hospital on a battlefield — but finally we have reached a situation where we can calmly think about the long-term future.
“A taskforce two years ago considered various options including geological disposal, vaporisation, burial underground, hydrogen release or release into the sea.
“Of those five options, we are trying to make a comprehensive assessment looking at options, but also reputational measures.”
http://www.abc.net.au/news/2018-03-02/fukushimas-radioactive-water-still-a-dilemma-for-japanese-gov/9504072

March 2, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

TEPCO defends Fukushima ‘ice wall,’ but it is still too porous

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Rows of tanks holding contaminated groundwater are seen at the Fukushima No. 1 nuclear power plant in February.
 
The “frozen soil wall” erected around the crippled reactor buildings at the Fukushima No. 1 nuclear power plant at huge taxpayer expense appears limited in keeping groundwater from flowing in.
Tokyo Electric Power Co., which operates the plant, said March 1 that 95 tons of radioactive water has been reduced a day on average between December and early February because of the underground barrier.
“Contaminated groundwater was cut in half due to the wall,” a TEPCO official said.
TEPCO estimated that the volume of polluted groundwater would have amounted to about 189 tons if the ice wall had not been in place during that period.
The utility also said the amount of polluted groundwater was reduced by about 400 tons a day now due to combined measures, such as the wall and wells pumping up water, compared with before such measures were taken.
But Toyoshi Fuketa, chairman of the Nuclear Regulation Authority, has insisted that the wells, not the wall, are the “key” to controlling the groundwater, voicing skepticism about the role of the ice wall.
The utility is proceeding with work to reinforce the wells.
The 34.5 billion yen ($322 million) frozen soil wall project began in 2014 to lay out the 1,500-meter-long underground wall around the No. 1-4 reactor buildings.
A large number of pipes were inserted to a depth of 30 meters to circulate liquid with a temperature of minus 30 degrees through them to freeze the surrounding soil.
It was designed to prevent groundwater from flowing into the plant and mixing with highly radioactive water in the basements of the buildings.
TEPCO’s recent assessment of the effectiveness of the frozen soil wall came after temperatures around the structure dropped to below zero following work that began last August to freeze the remaining final section of the wall.
But experts pointed out that the utility’s assessment is based on figures only when there was little rain.
The water volume rose to 1,000 tons or so a day in late October when two typhoons struck the area.
TEPCO believes that the surge at that time is largely attributable to the downpours from the typhoons.
Heavy rain accumulated in the basement after flowing down holes in the ceilings caused by hydrogen explosions during the 2011 triple meltdown.
It costs more than 1 billion yen a year in electricity fees to keep the wall frozen.
The company plans to remove all the groundwater from the buildings by 2020 so that it can begin work to decontaminate the facilities later.

March 2, 2018 Posted by | Fukushima 2018 | , | Leave a comment

TEPCO asked subsidiary to underestimate tsunami threat at Fukushima nuke plant: worker

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Tokyo Electric Power Co. (TEPCO) asked a subsidiary in 2008 to underestimate the scale of tsunami that could hit the Fukushima No. 1 Nuclear Power Plant before tsunami devastated the facility in March 2011, a subsidiary employee told a court.
 
The worker at Tokyo Electric Power Services Co. (TEPSCO) appeared as a witness at the hearing of three former TEPCO executives under indictment on charges of professional negligence resulting in death and injury at the Tokyo District Court on Feb. 28.
 
The man played a key role in TEPSCO’s estimate of the scale of possible tsunami, which could hit the premises of the plant, between 2007 and 2008.
 
Based on a long-term evaluation by the government’s Headquarters for Earthquake Research Promotion, the employee estimated that tsunami up to 15.7 meters high could hit the atomic power station. In its evaluation, the quake research headquarters had warned that a massive tsunami could occur off the Sanriku region including Fukushima Prefecture. The area was later devastated by a massive tsunami triggered by the March 11, 2011 Great East Japan Earthquake, causing the Fukushima nuclear crisis.
 
In his testimony, the employee told the court that he briefed TEPCO headquarters of the outcome of TEPSCO’s estimate of possible tsunami in March 2008. An employee at TEPCO headquarters subsequently asked the witness whether the estimated scale of possible tsunami could be lowered by changing the calculation method.
 
In response, the employee recalculated the possible tsunami based on different movements of tsunami waves he assumed, but he obtained an all but identical figure, the employee told the court hearing. He added that in the end, the prediction was not accepted as the utility’s estimate of possible tsunami hitting the power plant.
 
The man testified that his estimation of up to 15.7-meter-high tsunami hitting the power plant was “within the scope of his assumption because the calculation was based on the 1896 Sanriku earthquake that triggered over 30-meter-high tsunami.”
 
During the hearing, court-appointed lawyers, acting as prosecutors to indict the three former TEPCO executives, said that TEPCO headquarters considered measures to protect the Fukushima No. 1 nuclear complex from tsunami after being briefed of the outcome of TEPSCO’s tsunami estimate.
 
Nevertheless, the lawyers asserted that those who were on the company’s board at the time postponed drawing up tsunami countermeasures by deciding to commission the Japan Society of Civil Engineers to look into the matter, eventually opening the door to the nuclear crisis.
 
Public prosecutors had decided not to indict the three former TEPCO executives. However, under the Act on Committee for Inquest of Prosecution, court-appointed lawyers prosecuted them after a prosecution inquest panel comprising members selected from among the public concluded twice that the three deserved indictment.
 

March 2, 2018 Posted by | Fukushima 2018 | , , , | Leave a comment

TEPCO: Frozen soil wall effect limited

 

2018/03/01
Tokyo Electric Power Company, or TEPCO, says an underground frozen soil wall around its Fukushima Daiichi nuclear plant has had a limited effect in reducing groundwater contamination.
 
The 1.5-kilometer-long barrier is designed to keep groundwater from flowing into reactor buildings that were damaged by the March 2011 earthquake, tsunami and nuclear meltdowns.
 
The wall was expected to be the main defense against groundwater contamination, as about 500 tons of water was being tainted daily by radioactive substances.
 
TEPCO officials on Thursday estimated the amount of new contaminated water to have decreased by about 95 tons a day from before the wall was built.
They said the estimate is based on 3 months of data including that from before and after the wall was almost completed last November.
 
TEPCO had introduced a so-called sub-drain system for pumping up water from wells dug around the buildings.
 
The officials estimated that the 2 measures resulted in a decrease of 380 tons of tainted groundwater a day, suggesting the wall’s effectiveness is limited and lower than that of the drain method.
 
The government plans to ask experts to look into whether the utility’s estimate is accurate.
 
Public funds worth over 300 million dollars have been used to build the wall. Its annual operating cost exceeds ten million dollars.
https://www3.nhk.or.jp/nhkworld/en/news/20180301_26/
icewall march 1 2018.jpg

March 1, 2018 Posted by | Fukushima 2018 | , , , | Leave a comment

Radiation levels in Fukushima zones higher in 2017 than 2016, and still above government target despite cleanup: Greenpeace Japan

Look how the Japanese media are routinely censoring the news about the Fukushima situation.
In the first article  about the Greenpeace recent report, a short article published in Australia, are clearly stated:
1. Fukushima still has radiation 100 times higher than normal.
2. Greenpeace warned all areas surveyed, including those where people have been allowed to return, had levels of radiation similar to an active nuclear facility “requiring strict controls”, despite the fact that residents had lifted restrictions on access after years of decontamination efforts.
3. “This is public land. Citizens, including children and pregnant women returning to their contaminated homes, are at risk of receiving radiation doses equivalent to one chest X-ray every week.
4. This is unacceptable and a clear violation of their human rights,” Jan Vande Putte with Greenpeace Belgium, and leader of the survey, said.
In the second article about the Greenpeace recent report, a longer article published by the Japan Times in Japan, all those clearly stated 4 points have now disappeared, vanished, having been censored and left out, or spinned down, reduced, minimized such as:
1. “radiation 100 times higher than normal” becomes ” radiation levels higher than the government-set target of 0.23 microsieverts per hour, ranging from 0.2 to 0.8 microsieverts per hour” , meaning 4 times higher than the Japanese government-set target.
This is a typical example that shows you how the Japanese media, unfree from the Japanese government heavy censorship, have been for the past 7 years lying, hiding the true facts of the ongoing yet unsettled nuclear disaster in Fukushima, to the majority of the Japanese population.
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A member of Greenpeace checks radiation levels in the village of Iitate in Fukushima Prefecture last October. | GREENPEACE / VIA KYODO
March 1, 2018
Fukushima radiation still high: Greenpeace
A new report by Greenpeace says Fukushima, the sight of 2011’s nuclear accident after an earthquake, still has radiation 100 times higher than normal.
Greenpeace says towns in Japan’s Fukushima prefecture, close to the disaster-hit Fukushima Daiichi nuclear power plant, are exposed to excessive levels of radiation.
In a report published on Thursday, Greenpeace warned all areas surveyed, including those where people have been allowed to return, had levels of radiation similar to an active nuclear facility “requiring strict controls”, despite the fact that residents had lifted restrictions on access after years of decontamination efforts.
“This is public land. Citizens, including children and pregnant women returning to their contaminated homes, are at risk of receiving radiation doses equivalent to one chest X-ray every week. This is unacceptable and a clear violation of their human rights,” Jan Vande Putte with Greenpeace Belgium, and leader of the survey, said.
Japanese authorities have said these areas are progressively returning to normality after the massive 9.1-magnitude earthquake and resulting tsunami which struck on March 11, 2011, triggering the nuclear disaster at Fukushima.
The survey said that in the towns of Namie and Iitate, located between 10 and 40 kilometres from the Fukushima Daiichi plant and where evacuation orders were partially lifted in March 2017, radiation levels continue to be “up to 100 times higher than the international limit for public exposure”.
Greenpeace also noted the “ineffectiveness of decontamination work” in these areas, saying there remained a “significant risk to health and safety for any returning evacuee”, adding that Tokyo’s policy of “effectively forcing people to return by ending housing and other financial support is not working”.
The Japanese government had said radiation levels in the reopened zones posed no risk to human health, noting that its data was corroborated by the country’s medical experts and organisations such as the United Nations Scientific Committee on the Effects of Atomic Radiation.
Considered the worst nuclear disaster since the 1986 Chernobyl disaster in Ukraine, the accident at Fukushima displaced tens of thousands of people, caused serious damage to the local economy.
http://www.news.com.au/world/breaking-news/fukushima-radiation-still-high-greenpeace/news-story/9e0eb100271bcf45113160eef181dc0c
Radiation levels in Fukushima zones higher in 2017 than 2016, and still above government target despite cleanup: Greenpeace Japan
Following the 2011 nuclear crisis, radiation levels at houses and areas nearby in a Fukushima village remain around three times higher than the government target despite cleanup work having been performed, an environmental group has said.
In some areas of the village of Iitate and the town of Namie, levels of radioactivity detected at some points among tens of thousands checked in surveys last September and October were higher than they had been the previous year, Greenpeace Japan said in a report released Thursday.
Most of the six houses surveyed in Iitate, located around 40 kilometers northwest of the crippled Fukushima No. 1 complex, logged radiation levels higher than the government-set target of 0.23 microsieverts per hour, ranging from 0.2 to 0.8 microsieverts per hour.
Some areas in the village had seen radiation levels rise from 2016, Greenpeace said. “There is a possibility (the environment) was contaminated again as radioactive materials that had accumulated in nearby forests may have moved around,” it said.
One house, located near a municipal office with slightly wooded areas nearby, marked lower radiation levels compared with the previous 2016 survey but levels at another five houses — which are near forests that have yet to be cleaned up — have remained almost the same.
The points surveyed covered areas in Iitate and Namie where evacuation orders have been lifted as well as some parts of Namie that remain designated as “difficult to return” zones following the Fukushima nuclear disaster, which was triggered by the massive March 2011 earthquake and tsunami.
The survey also showed that the effects of cleanup work conducted in 2011 and 2012 in the Tsushima district of Namie, located 40 km northwest of the Fukushima plant, had been limited, with one house there logging radiation levels of 5.8 microsieverts per hour at the highest readings and 1.3 microsieverts per hour on average.
The district is among areas designated as special reconstruction zones by the government. The state plans to carry out cleanup work and promote infrastructure development intensively at its expense to make such areas livable again.
https://www.japantimes.co.jp/news/2018/03/01/national/radiation-levels-fukushima-zones-higher-2017-2016-still-government-target-despite-cleanup-greenpeace-japan/

March 1, 2018 Posted by | Fukushima 2018 | , , , , , , | 1 Comment

Court told ex-Tepco Execs were informed barriers could prevent tsunami flooding at Fukushima plant

Feb 28, 2018
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The devastated Fukushima No. 1 nuclear power plant is seen in this April 2011 file photo
 
An employee with a subsidiary of Tokyo Electric Power Company Holdings Inc. testified in court Wednesday that the unit reported a need to install tide barriers to prevent flooding from a tsunami well before the March 2011 nuclear accident at Tepco’s Fukushima No. 1 nuclear plant.
According to the worker, the Tepco unit produced an estimate in March 2008 on the basis of long-term assessments released by a government organization, saying that a tsunami could occur with a height of 15.7 meters, which is above ground level at the nuclear plant site.
The estimate was presented at a meeting in June the same year that was attended by Sakae Muto, a former Tepco vice president.
The worker testified during a hearing at the Tokyo District Court that the Tepco unit estimated the tsunami height to reflect the latest information on a possible massive earthquake off Fukushima Prefecture, home to the now-devastated nuclear plant.
After finding that the nuclear plant site was vulnerable to flooding, the subsidiary reported at the meeting that installing 10-meter tide barriers would provide protection from a tsunami, the worker said.
The worker gave the testimony as a witness in the trial of three former Tepco executives, including Muto, 67, who were indicted in February 2016 for allegedly neglecting to take measures against massive tsunami. A prosecution inquest panel comprising ordinary citizens has overruled decisions by public prosecutors twice not to charge the executives. In the indictment, they were charged with professional negligence resulting in death and injury over the accident.
Lawyers appointed by the district court to act as prosecutors have said that former Tepco Chairman Tsunehisa Katsumata, 77, and former Vice President Ichiro Takekuro, 67, were also informed of the tsunami estimates on separate occasions. The lawyers claimed that the three former Tepco executives could have foreseen that a massive tsunami might hit the nuclear power plant.
The former executives denied the claim during the first hearing in their trial in June 2017, saying that the company would have been unable to prevent the accident even if measures were taken based on the estimate.

February 28, 2018 Posted by | Fukushima 2018 | , , , , | Leave a comment

Fukushima Daiichi groundwater inflow increased 4 times as much as normal

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2018/2/26
Tokyo Electric Power Company announced on 26th that the amount of groundwater flowing into the basement of the Fukushima Daiichi reactors buildings 1 and 2 began to increase in February and temporarily nearly quadrupled. There is a possibility that the influx may have increased due to the repair work of the drainage passage passing through the vicinity.
According to TEPCO, the inflow from January 1 to February 8 this year is about 48 tons per day on average. However, despite the fact that it did not rain from February 8 to 15, it increased to an average of about 131 tons. It peaked at about 179 tons on the 19th and started to decline from 20th.
In the Fukushima Daiichi nuclear plant, groundwater flows into the basements of the buildings and mixes with contaminated water, leading to an increase in new contaminated water.
https://this.kiji.is/340825547233838177

February 27, 2018 Posted by | Fukushima 2018 | , | Leave a comment

Drone to map radiation within Fukushima plant

27 February 2018
A small drone is to be deployed to measure radiation levels at the damaged reactors at Japan’s Fukushima Daiichi nuclear power plant. The UK-developed RISER – Remote Intelligence Survey Equipment for Radiation – has already been used successfully at Sellafield, in England.
 
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The RISER drone undergoing trials at Sellafield (Image: NDA)
 
The lightweight RISER drone uses lasers to self-navigate deep inside hazardous facilities where GPS signals cannot reach. It combines two separate pieces of technology: drones and radiation-mapping software. Each received research and development funding through the Nuclear Decommissioning Authority (NDA) and fellow government agency, Innovate UK.
Cockermouth, Cumbria-based computing and electronics engineering firm Createc’s N-Visage radiation mapping software project was boosted during its early stages in 2009 by a GBP50,000 (USD70,000) investment from the NDA’s R&D portfolio.
Three years later, the NDA joined other government organisations to invest further funds in a wide range of innovative nuclear projects. This led to the collaboration between Createc and Bedford-based aerial systems specialist Blue Bear Systems Research. This collaboration led to RISER.
The drone is less than one metre in diameter and navigates using its own internal ‘collision avoidance’ capability. Able to manoeuvre accurately inside complex industrial spaces, data is transmitted to the mapping system and clearly displayed, highlighting areas of contamination, its developers say.
The N-Visage tailor-made technology maps radiation with “pinpoint accuracy, producing a high-definition 3D picture of contamination, quickly and safely”.
After a series of on-site trials at Sellafield, RISER was put into decommissioning action. The drone has been used to collect vital information about conditions in the highly-contaminated Windscale Pile chimney. This data will be used to establish how the chimney can be cleaned out and finally dismantled.
RISER was first used inside one of the reactor buildings at Japan’s Fukushima-Daiichi plant several years ago, and is now set to return, mounted on the drone.

February 27, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Roof completed for removal of spent fuel rods at Fukushima plant

February 21, 2018
Work was completed Feb. 21 on a half-cylinder roof designed to trap radioactive substances emitted when spent fuel rods are removed from the No. 3 reactor building at the Fukushima No. 1 nuclear plant.
Tokyo Electric Power Co., the plant’s operator, plans to remove the spent fuel from the building’s storage pool as early as this autumn.
Construction work on the roof–23 meters wide and 57 meters long–started in July 2017.
The final piece, weighing about 55 tons, was lifted by a crane and put into place on Feb. 21. The roof is located directly above the storage pool.
A hydrogen explosion severely damaged the original roof of the No. 3 reactor building days after the March 2011 Great East Japan Earthquake and tsunami triggered the meltdowns at the plant.
The 566 fuel assemblies in the storage pool pose a serious risk in the event of another disaster striking the plant.
Completion of the roof should advance TEPCO’s plans to remove the fuel rods as soon as possible.
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The final part of a roof is put in place on the top of the No. 3 reactor building at the Fukushima No. 1 nuclear power plant on Feb. 21.
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A photo taken from an Asahi Shimbun helicopter on Feb. 21 shows the completion of work for a roof at the No. 3 reactor building of the Fukushima No. 1 nuclear power plant on Feb. 21.
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The half-cylinder roof is designed to prevent radioactive substances from escaping during fuel-rod removal work in the No. 3 reactor building at the Fukushima No. 1 nuclear plant.

 

February 25, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Fukushima plant reactor #3 gets new roof cover

 

 
Workers at the crippled Fukushima Daiichi nuclear power plant have finished installing a new roof covering for the No.3 reactor building.
The work started last August to set up a dome-shaped cover. It is part of preparations for removing nuclear fuel from the reactor’s storage pool. A total of 566 spent and unused fuel units remain in the storage pool of the No. 3 reactor.
On Wednesday, workers installed the last part of the cover, which is 17 meters high and 22 meters wide, and weighs 55 tons.
The cover will prevent radioactive materials from spreading, and shield the building from winds.
Reactors at the Fukushima plant suffered meltdowns after a quake-triggered tsunami hit the plant on March 11th, 2011. The fuel units left in storage pools need to be removed as part of decommission work at the plant.
The plant’s operator, Tokyo Electric Power Company, will clear the pool of rubble and provide workers with training on remotely handling devices for the fuel removal.
Then, it plans to start removing nuclear fuel units from the No.3 reactor’s storage pool in autumn this year, ahead of those of other damaged reactors.

February 22, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Key figures for the seventh anniversary

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February 17, 2018

Translation by Herve Courtois from the ACRO article

http://fukushima.eu.org/chiffres-cles-septieme-anniversaire/

All the figures quoted in this article are from TEPCO and the Japanese government. We can safely assume the true figures to be somehow higher, as we know from the past 7 years that TEPCO and the Japanese government have never been straightforward with their figures.

 

As we approach the seventh anniversary of the nuclear disaster at the Fukushima Daiichi nuclear power plant, here are some key figures as they appear in the media and official websites. This article will be updated as they appear.

Situation of the reactors

The work is aimed primarily at securing the damaged reactors that are still threatening. Nearby, the dose rates are such that the work time of the workers must be very limited, which complicates the work.

Reactor # 4

The reactor vessel was empty on March 11, 2011 so there was no core melting, but a hydrogen explosion destroyed the reactor building. Since December 2014, the reactor fuel pool has been emptied and work is stopped because it is no longer threatening. http://www.tepco.co.jp/en/press/corp-com/release/2014/1246703_5892.html

The few dose rates available inside the reactor building are here expressed in mSv / h, knowing that the limits are in mSv / year. They date from 2016. www.tepco.co.jp/en/nu/fukushima-np/f1/surveymap/images/sv-u4-20160630-e.pdf

Reactor # 3

There was a core meltdown and a hydrogen explosion destroyed the reactor building. All top debris were removed using remotely controlled gear. A new building is being finished. Fuel removal is expected to begin this year and end in 2019.

The first images taken inside the containment led to a revision of the core fusion scenario.

http://photo.tepco.co.jp/en/date/2017/201707-e/170721-01e.html

http://photo.tepco.co.jp/en/date/2017/201707-e/170722-01e.html

www.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170722_01-e.pdf

The few dose rates available inside the reactor building are here expressed in mSv / h, knowing that the limits are in mSv / year. They date from 2016.

www.tepco.co.jp/en/nu/fukushima-np/f1/surveymap/images/sv-u3-20160630-e.pdf

There would be between 188 and 394 tonnes of corium in this reactor, with a nominal value of 364 tonnes for reactor No. 3. The latter contains MOx fuel, which contains plutonium. To know more:

http://www.fukushimaminponews.com/news.html?id=739

Reactor # 2

There was a melting of the core, but the reactor building is whole. TEPCO has not started removing used fuel from the pool. The company sent several robots into the containment to locate the corium, the mixture of molten fuel and debris.

Several series of images have been put online by the company. Those taken in January 2017 were analyzed and put back online in December 2017. There is a gaping hole just below the vessel, most likely due to the passage of molten fuel.

www.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_171130_01-e.pdf

Those obtained in January 2018 at the bottom of the containment enclosure show what TEPCO thinks is corium and fragments of fuel assembly.

http://photo.tepco.co.jp/en/date/2018-e/201801-e/180119-01e.html

http://www.tepco.co.jp/en/news/library/archive-e.html?video_uuid=uikti9fd&catid=61785

www.tepco.co.jp/en/nu/fukushima-np/handouts/2018/images/handouts_180119_01-e.pdf

Dose rates inside the containment enclosure are lethal within minutes. The latest results published following the January 2018 exploration are quite surprising: not higher near what TEPCO thinks is corium, but higher outside.

www.tepco.co.jp/en/nu/fukushima-np/handouts/2018/images/handouts_180201_01-e.pdf

The few dose rates available inside the reactor building are here expressed in mSv / h, knowing that the limits are in mSv / year. They date from 2016.

www.tepco.co.jp/en/nu/fukushima-np/f1/surveymap/images/sv-u2-20160630-e.pdf

There would be between 189 and 390 tonnes of corium in this reactor, with a nominal value of 237 tonnes. To know more:

http://www.fukushimaminponews.com/news.html?id=739

Reactor # 1

There was a core meltdown and a hydrogen explosion destroyed the reactor building. This building was covered by a new structure in 2011, which was completely dismantled in November 2016. TEPCO began removing the debris from the upper part of the reactor, then rebuilding a new structure to empty the pool. fuels.

The dose rates inside the reactor building are here expressed in mSv / h, knowing that the limits are in mSv / year. They date from 2016.

www.tepco.co.jp/en/nu/fukushima-np/f1/surveymap/images/sv-u1-20160630-e.pdf

There would be between 232 and 357 tons of corium in this reactor, with a nominal value of 279 tons. To know more:

http://www.fukushimaminponews.com/news.html?id=739

Reactors 5 and 6

Reactors 5 and 6 were partially unloaded on March 11, 2011, and a backup diesel generator was still functional, which prevented the core from melting. These reactors are now fully unloaded and will be dismantled.

Contamination of the plant

The last dose rates on the plant site published by TEPCO are from February 2017:

Groundwater also remains contaminated. Figures to come.

 

 

Contaminated water

The fuel that has melted and drilled the vessels must always be cooled. To this end, TEPCO injects 72 m3 of water per day into each of the reactors 1, 2 and 3 for this purpose. This makes a total of 216 m3 per day. This water is highly contaminated by contact with the molten fuel and infiltrates the basements of the reactor and turbine buildings where it mixes with the groundwater that infiltrates it.

www.tepco.co.jp/en/press/corp-com/release/betu18_e/images/180205e0101.pdf

At the beginning of the disaster, the infiltration amounted to about 400 m3 per day, which became contaminated and had to be stored in tanks. Inversely, the water of the basements, highly contaminated, leaked towards the groundwater then the ocean.

To reduce groundwater seepage, TEPCO pumps upstream of reactors before this water is contaminated and releases it directly into the ocean. It has also built a barrier all along the shoreline and pumps groundwater at the foot of the reactors. Part of this is partially decontaminated and released into the ocean. Another part, too contaminated, is mixed with the pumped water in the basements of the reactors to be put in tanks after treatment, waiting for a better solution.

The last barrier put in place is the freezing of the ground all around the 4 accidented reactors, on 1.4 km in order to stop the infiltrations. After many setbacks, the ice wall is finished since November 2017, but the effect remains limited. Even the Nuclear Regulatory Authority, the NRA, seriously doubts the effectiveness of this technique, which it now considers secondary.

A year ago, during our previous assessment, TEPCO pumped 135 m3 of contaminated water daily in the basements of reactor and turbine buildings, in addition to the one it injected for cooling and 62 m3 of groundwater, which made a total of 197 m3 which accumulated daily in tanks after treatment. It’s more in case of rain, or even more during typhoons.

www.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170213_01-e.pdf

Now that the soil freeze is over, these flows have been reduced. According to the latest report published by the company, 75 m3 of groundwater infiltrate daily in the basements of reactors to which must be added 15 m3 per pumped groundwater too contaminated to be treated directly before discharge to sea. therefore makes a total of 90 m3 per day. These values correspond to a week without rain. In case of heavy rainfall, it is much more, even if TEPCO has paved and concreted all soils to limit infiltration.

www.tepco.co.jp/en/nu/fukushima-np/handouts/2018/images/handouts_180205_01-e.pdf

The water pumped into the basements is treated and stored in tanks at the plant site. TEPCO removes 62 radioelements, but it remains notably tritium, radioactive hydrogen, which is difficult to separate. The company announces that it has already treated 1,891,070 m3 of contaminated water, which generated 9,219 m3 of highly radioactive liquid waste and 597 m3 of radioactive sludge. Part of this is used for cooling and the rest is stored in tanks. According to the company, the stock of treated or partially treated water amounts to 1,037,148 m3 plus 35,010 m3 of water in the basements of the reactor and turbine buildings. There are nearly a thousand tanks to keep this water that occupy almost the entire site of the plant.

www.tepco.co.jp/en/press/corp-com/release/betu18_e/images/180205e0101.pdf

What to do with this treated water? After considering several unrealistic solutions, there remains only the rejection at sea. The concentration in tritium would be one to five million becquerels per liter, which is more than the authorized limit, set at 60 000 Bq / L. But, just dilute, as is done in normal operation. The problem is rather on the side of the total stock, estimated at 3.4 PBq (3.4 billion million becquerels), which represents about 150 years of rejection to the authorized limit.

www.meti.go.jp/earthquake/nuclear/pdf/140424/140424_02_003.pdf

By way of comparison, the discharge authorization at the Areva plant in La Hague is 18.5 PBq for tritium and the actual releases in recent years ranged from 11.6 to 13.4 PBq per year. The Fukushima tritium stock therefore represents 3 ½ months of discards at La Hague. What make the Japanese authorities jealous!

https://apnews.com/5d0932a5a57a4c94821d7e8b5b3f8d4b/japan-prepares-release-tritium-fukushima-plant

On the other hand, we do not know the concentration of other radioelements after filtering. This is important for an impact study before rejection. Toyoshi Fuketa, the president of the Nuclear Regulatory Authority, has asked for a decision to be made this year, saying that the rejection at sea is the only solution. The preparation of the rejection should take two to three years, according to him, and TEPCO will quickly run out of space.

https://www.japantimes.co.jp/news/2018/01/11/national/regulator-urges-tepco-release-treated-radioactive-water-damaged-fukushima-no-1-nuclear-plant-sea/

Workers

At the Fukushima daiichi nuclear power plant

• From March 11, 2011 to March 31, 2016, 46,956 workers were exposed to ionizing radiation at the site of the Fukushima daï-ichi power station, including 42,244 subcontractors. It is the subcontractors who take the highest doses, with an average that varies from 0.51 to 0.56 mSv per month between January and February 2016. It is between 0.18 and 0.22 for employees of TEPCO.
There are also 1,203 people who have a higher limit to continue to enter the site. Their average cumulative dose since the beginning of the accident is 36.49 mSv and the maximum value of 102.69 mSv.

www.mhlw.go.jp/english/topics/2011eq/workers/irpw/ede_160430.pdf

• On April 1, 2016, TEPCO reset all meters. For example, 174 workers who exceeded the dose limit of 100 mSv over 5 years may return. Since then, until December 31, 2017, 18,348 people have worked in controlled areas, including 16,456 subcontractors (90%). It is impossible to know how many of them have been exposed in the first five years. During this period, subcontractors took a cumulative average dose of 4.29 mSv, with a maximum of 60.36 mSv, while TEPCO employees took a cumulative average dose of 1.79 mSv with a maximum of 22.85 mSv. Subcontractors thus took 95.4% of the cumulative collective dose of 74 men.sieverts.

https://www.japantimes.co.jp/news/2016/04/01/national/150-fukushima-no-1-workers-got-maximum-radiation-dose-start-crisis-can-now-return-plant/#.VwAt8quVSiu

www.tepco.co.jp/en/press/corp-com/release/betu18_e/images/180131e0101.pdf

TEPCO has put online many other data on the doses taken, with distributions by age, year …

http://www.tepco.co.jp/en/press/corp-com/release/2018/1475822_15409.html

TEPCO reduced the risk premiums paid to workers because dose rates decreased on the site. This subject would be one of the main complaints of the staff engaged on the site. It could reach 20,000 yen (150 €) per day, even if, for the subcontractors, this premium was punctuated at each level of subcontracting, to be reduced, sometimes, to less than half. In March 2016, TEPCO divided the site of the accident site into 3 zones, red, yellow and green, depending on the level of risk. But for many workers, this zoning is meaningless: debris from the red zone is transferred to the green zone. The dust raised by the machines does not respect the boundaries … Thus, subcontractors wear protective equipment such as masks in the green zone, even if TEPCO does not require it.

https://www.japantimes.co.jp/news/2018/02/17/national/media-national/media-reports-de-romanticize-cleanup-work-fukushima-nuclear-power-plant/

About the decontamination sites

In the evacuated areas, it is the government that is prime contractor for the decontamination sites and in the areas not evacuated, it is the communes. The monthly report of the Ministry of the Environment (source, page 16) states:

13 million decontaminators in the evacuated areas and

17 million decontaminators in the areas not evacuated according to the data transmitted by the communes.

josen.env.go.jp/en/pdf/progressseet_progress_on_cleanup_efforts.pdf

These numbers are completely unrealistic. This is probably the number of contracts signed. This means that the authorities do not know the number of decontaminators and therefore do not know the individual doses.

An individual dosimetric follow-up was introduced in November 2013 for the decontaminators (source in Japanese) who work in the evacuated zone and who are subject to the same dose limits as the nuclear workers. Data for 2016 show 36,000 decontaminators. We are far from the millions of decontaminators reported by the Ministry of the Environment. The majority (87%) received a dose of less than 1 mSv / yr and the highest dose was 7.5 and 10 mSv. There is also data by number of sites or by zone.

http://www.rea.or.jp/chutou/koukai_jyosen/H28nen/English/honbun_jyosen-h28-English.html

www.rea.or.jp/chutou/koukai_jyosen/H28nen/English/1zuhyo_jyosen-H28-English.pdf

The most recent data in English, dated January 8, 2018, covers the period October 2016 – September 2017. Doses are reported by period of 3 months while the limits are annual. It is difficult to interpret these numbers. If it appears that the vast majority of decontaminators received less than 1 mSv over 3 months, it is not known how much below this limit over one year. The average annual dose is 0.5 mSv.

www.rea.or.jp/chutou/koukai_jyosen/shihanki/English/From%20October%202016%20to%20September%202017.pdf

Other people exposed

I did not find any official data on the doses taken by those who continued to work in the evacuated area or the many police officers who guard and patrol the restricted areas.

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Mapping of radioactive pollution

• The latest aerial mapping of radioactive pollution around the Fukushima daiichi nuclear power station was made in November 2016 and is available online at the dedicated site.
The immediate vicinity of the nuclear power plant has not been recontrolled, it seems.

https://ramap.jmc.or.jp/map/eng/

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Decontamination

Decontamination of evacuated areas is the responsibility of the government. Elsewhere, where the external exposure could exceed 1 mSv / year, it is the municipalities that have to deal with it. See the latest report published by the Ministry of the Environment:

josen.env.go.jp/en/pdf/progressseet_progress_on_cleanup_efforts.pdf

In the evacuated zone, decontamination is complete, except in the parts classified as “difficult return zones” where the external exposure could exceed 50 mSv / year. Decontamination took place only in populated and agricultural areas, not in forests. The ministry announces 22,000 decontaminated homes, 1,600 ha of roads, streets, lanes …, 8,500 ha of agricultural land and 5,800 ha of forest near residential areas.

In the non-evacuated areas, 104 communes were initially concerned, in Fukushima, Iwate, Miyagi, Ibaraki, Tochigi, Gunma, Saïtama and Chiba prefectures and it went down to 92 by simple radioactive decay. The decontamination work is completed in 89 of them and remains to be done in 3 others. The ministry announces 418,582 homes decontaminated in Fukushima and 147,656 in other provinces, 11,958 public facilities in Fukushima and 11,803 in other provinces. There are also 18,403 km of roads, streets, roads in Fukushima and 5,399 in other provinces, 31,043 ha of agricultural land in Fukushima and 1,588 ha in other provinces.

For so-called difficult return zones, the government will decontaminate a center in Futaba and Okuma in order to be able to affirm that it has not abandoned any commune. The end of the work is scheduled for 2022. Who will come back after 11 years of evacuation? This work in a highly contaminated zone will generate exposure of the decontaminators to ionizing radiation. As there is no threshold of safety, the first principle of radiation protection requires the justification of these exposures and this has not been done.

http://www.asahi.com/ajw/articles/AJ201708010034.html

http://www.asahi.com/ajw/articles/AJ201701300051.html

The Ministry of the Environment has budgeted 2.6 trillion yen (24.79 billion dollars) until 2016 to finance the decontamination work. Half is for evacuated areas, without taking into account the so-called difficult return zone and the other half for non-evacuated areas.

Radioactive waste from decontamination

• See our summer 2016 report on the problem of waste from decontamination. Organic waste is incinerated and ash must be stored as industrial waste. Soils, for their part, must be stored for 30 years on a site of 16 km2 around the Fukushima daï-ichi plant, the time to find a final solution.

fukushimaontheglobe.com/wp-content/uploads/6-Stories-Facts-from-Fukushima_1228_2_Optimized.pdf

• According to the Ministry of the Environment, the decontamination of the evacuated areas has generated 8,400,000 m3 of waste containing radioactive soils to which are added approximately 7,200,000 m3 in the areas not evacuated (6,800,000 m3 in Fukushima and 400,000 m3 in the other provinces concerned).

josen.env.go.jp/en/pdf/progressseet_progress_on_cleanup_efforts.pdf

• Regarding the 16-square-kilometer (1,600-hectare) contaminated soil storage site with a capacity of 22 million cubic meters, the government has only been able to lease or purchase 48.4% of the surface area , knowing that 21% of the land already belonged to the government or municipalities. That was 18% a year ago.

josen.env.go.jp/en/pdf/progressseet_progress_on_cleanup_efforts.pdf

This site will only accept Fukushima waste. The ministry announces that it has transferred 404,773 bags of about one cubic meter to this site in 2017. It is still far from the millions of cubic meters, but it required 67,146 truckings. And it will take as much transport to resume in 30 years … The total volume stored for the moment is 633 889 m3.

To learn more about this storage site.
• For radioactive waste from other provinces, the authorities prefer landfill even if they are struggling to find sites (source).

http://josen.env.go.jp/en/storage/ josen.env.go.jp/en/pdf/progressseet_progress_on_cleanup_efforts.pdf

• In the meantime, there is waste everywhere, as far as the eye can see. See the Greenpeace videos.

https://www.youtube.com/watch?v=5sgixr-SC4g

https://www.youtube.com/watch?v=fveJc_cMsKM

https://www.greenpeace.de/sites/www.greenpeace.de/files/publications/fukushima-bericht-oktober_2017_v2.pdf

Evacuated areas

• The last evacuation orders were lifted on April 1, 2017 and it remains mostly so-called back difficult areas where access is prohibited.

3.png

Cost of the disaster

Official figures for the cost of the disaster were revised upwards in December 2016 to 21.5 trillion yen (216.88 billion dollars) and have not changed since. This includes the dismantling of the Fukushima daï-ichi reactors, worth 8 trillion yen (80.56 billion dollars), 7.9 trillion yen (79.32 billion dollars) for compensation, nearly 4 trillion yen (40.28 billion dollars) for decontamination and 1.6 trillion yen (16.11 billion dollars) for the temporary radioactive waste storage center.

This sum does not include the cost of storing the waste resulting from the dismantling of the damaged power station nor the creation of a decontaminated island in the so-called “difficult return” zones whose sole purpose is the non-disappearance of the villages concerned.

The bill for the nuclear disaster could be 50,000 to 70 trillion yen (520.67 to 719.02 billion dollars), which is 3 times higher than the government estimate, according to a study by the Japan Center for Economic Research.

TEPCo has already received a total of 8,032.1 billion yen (73.76 billion dollars at the current rate) in advance for compensation. This money is loaned without interest.

http://www.tepco.co.jp/en/press/corp-com/release/2018/1474320_15409.html

The government still holds a 50.1% stake in TEPCO.

Source: http://fukushima.eu.org/chiffres-cles-septieme-anniversaire/

February 19, 2018 Posted by | Fukushima 2018 | , , | 1 Comment

Media reports de-romanticize the cleanup work on the Fukushima nuclear power plant

p17-brasor-fukushima-a-20180218-870x579.jpgFront-line fight: Workers remove protective clothing after a shift at the Fukushima No. 1 nuclear plant in November 2011.

 
Most of the reliable reporting about the clean-up of the Fukushima No. 1 nuclear power plant since it suffered three meltdowns in March 2011 has been from on-site workers. Even when articles appear in major media outlets about the situation at the crippled reactor, it’s usually presented through the anonymous or pseudonymous firsthand experiences of the men on the front lines.
Some have become famous. The public would not know much about the situation without Kazuto Tatsuta’s manga series, “Ichiefu” (or “1F” — shorthand for “Fukushima No. 1”), the writings of former letter carrier and cleanup worker Minoru Ikeda, or the books and tweets of a man known as “Happy” who has been working as an employee at the plant.
Because these individuals directly address what they and their colleagues have gone through on a daily basis, the work they do has been de-romanticized. It’s not as heroic as initial foreign media reports made it out to be. If anything, it’s tedious and uncomplicated.
Workers are concerned about those matters that all blue-collar laborers worry about — pay and benefits — which isn’t to suggest they don’t think about the possible health risks of radiation exposure. Last October, Ikeda talked to the comedy duo-cum-nuclear power reporters Oshidori Mako & Ken on the web channel Jiyu-na Radio about potential false reports on radiation levels around Fukushima, although also touching on health issues that have not been reported by the mainstream media. His main point was that serious illnesses may not manifest themselves until years after workers quit the site and thus no longer qualify for worker’s compensation. In other words, the workers understand the risk. They just want to be fairly compensated for it.
In that regard, one of the most common gripes from on-site reporters is the “hazard compensation” (kiken teate) workers are supposed to receive. Recently, Tokyo Electric Power Company Holdings Inc. (Tepco), which is both responsible for the accident and in charge of the cleanup, announced a reduction in outlay associated with the hazard compensation, which is paid as a supplement to wages. This compensation can add as much as ¥20,000 a day to a worker’s pay, but now that Tepco says radiation levels have dropped, they will no longer provide the compensation, or, at least, not as much as they have been paying.
A special report in the Jan. 22 Tokyo Shimbun attempted to explain how this change will affect workers and the work itself. In March 2016, Tepco divided the work area into three zones: red, for high radiation levels; yellow, for some radioactivity; and green, for areas that had no appreciable radioactivity. Workers interviewed by Tokyo Shimbun say they’ve never liked this system because they feel it “has no meaning.” Rubble from the red zone is routinely transferred to the green zone, where heavy machinery kicks up a lot of dust, so there’s no physical delineation between zones when it comes to radiation levels. On the ground, this reality is addressed by subcontractors who make their employees in the green zone — which constitutes 95 percent of the work site — wear extra protective gear, even though Tepco doesn’t require it.
But the workers’ main gripe about the zone system is that most of them ended up being paid less and, as on-site workers have often explained, they weren’t getting paid as much as people thought they were. Contractors advertise high wages to attract workers, but then subtract things like room and board, utility fees, clothing and equipment. And it’s been known for years that the hazard compensation was more or less a racket gamed by the contractors standing between Tepco, which distributes the compensation, and the workers, who are supposed to be the beneficiaries. There can be up to six layers of contractors between Tepco and a worker, and each layer may take a cut of the compensation. In 2014, four workers sued Tepco for ¥62 million, saying they worked at the site but received none of the promised hazard compensation.
That situation still seems to be in play, according to Tokyo Shimbun. Several subcontractors told the newspaper they receive the compensation for their workers not from Tepco directly but from the contractor that hired them, and in most cases the compensation has been reduced, sometimes by more than half. One subcontractor said that a company above them actually apologized for the paucity of the compensation they were handing down because their “revenues had decreased.” The man known as Happy told Tokyo Shimbun that Tepco is ordering less work at the site, which means existing subcontractors may cut wages in order to compete for these dwindling jobs. Some contractors have even invested in the robots that are used to inspect the reactor, because they want the work to continue without interruption.
It was common practice to rotate out workers toiling in the highly radioactive areas regularly and quickly and then re-assign them to low-radiation areas. After some time they may have been rotated back into the high-radiation area, where pay is more. The man known as Happy says this sort of system now seems to be on the way out, and that makes sense if radiation is actually decreasing. However, he’s afraid that if there is another emergency that requires a sudden influx of workers, they won’t be available.
Tepco is obviously thinking of its bottom line, and the man known as Happy thinks the work should be managed by the government, which is contributing tax money to the cleanup. However, it seems only the Japan Communist Party is reading the dispatches from the plant. Last May, Japanese Communist Party lawmaker Taku Yamazoe questioned Tepco President Naomi Hirose about the hazard compensation in the Diet, and why the structure of payments to workers wasn’t clear.
Hirose said that while his company intends that the money goes to workers, he cannot say for sure that is the case because of the circumstances surrounding Tepco’s relationships with contractors. With work on the wane, it seems unlikely that those workers will see any of the money that’s owed to them, retroactively or otherwise.
https://www.japantimes.co.jp/news/2018/02/17/national/media-national/media-reports-de-romanticize-cleanup-work-fukushima-nuclear-power-plant/

February 18, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Inside a meltdown-hit Fukushima reactor building

February 17, 2018
Seven years on, Tepco aims to pull fuel out of Unit 3’s rubble-strewn pool
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A crane and dome-shaped roof have been erected on the top floor of Fukushima Daiichi’s No. 3 building, in preparation for removing rods and rubble from the spent fuel pool
 
FUKUSHIMA, Japan — As the Fukushima Daiichi nuclear disaster unfolded in March 2011, a hydrogen explosion ripped through the No. 3 reactor unit. Nearly seven years on, steel framing and other debris still litter the spent fuel pool, along with 566 fuel rods.
The painstaking process of removing the rods is expected to begin sometime in the fiscal year that starts in April. The fuel extraction will be a first for reactor Nos. 1-3 at the Tokyo Electric Power Co. Holdings facility, which was crippled by the earthquake and tsunami that hit northeastern Japan.
On Feb. 8, reporters from The Nikkei were allowed into the No. 3 building to get a sense of the work that awaits. 
A 20-minute bus ride from the town of Tomioka took us to Fukushima Daiichi. After donning masks and protective clothing, we walked toward Unit 3. An elevator slowly lifted us to the top floor of the building, about 36 meters up. There, a crane for moving the spent rods stood ready, wrapped in plastic sheeting. We peered down into the pool but could not see the fuel, which lies under 4 to 5 meters of water.
Large slabs of rubble that fell into the pool have been removed, but smaller pieces remain.
Other decontamination work is proceeding gradually. Radiation on the top floor was measured as high as 2,000 millisieverts per hour in the disaster’s immediate aftermath, but now it is less than 1 millisievert.
Still, caution is a must. Near the pool, our dosimeters displayed relatively high readings of up to 0.7 of a millisievert per hour. “The reading has climbed, so let’s leave for now,” a Tepco supervisor said. As we moved on, we frequently checked to ensure our exposure would not exceed 0.1 of a millisievert a day. 
 
Spent fuel has been removed from reactor No. 4, which was not operating when the tsunami hit the plant. But the job will be a challenge at the meltdown-stricken Unit 3. The rods and rubble will be extracted with heavy equipment operated remotely, from a separate administrative building. 
While it normally takes about two weeks to remove spent fuel, Tepco intends to proceed carefully over the course of two years.
https://asia.nikkei.com/Japan-Update/Inside-a-meltdown-hit-Fukushima-reactor-building

February 18, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

NOAA research plane flying over Alaska has detected enriched U-235

1-s2.0-S0265931X17308111-gr4.sml.gif

An aerosol particle containing enriched uranium encountered in the remote upper troposphere
 
Highlights
• We describe a highly unusual aerosol particle containing a very small amount of enriched uranium.
• The bulk of the particle probably came from combustion of heavy fuel oil.
• The particle was encountered when we were making no special attempt to sample radioactive material.
• We don’t know the source for this particle. It may indicate a novel source where enriched uranium was dispersed.
 
Abstract
We describe a submicron aerosol particle sampled at an altitude of 7 km near the Aleutian Islands that contained a small percentage of enriched uranium oxide. 235U was 3.1 ± 0.5% of 238U. During twenty years of aircraft sampling of millions of particles in the global atmosphere, we have rarely encountered a particle with a similarly high content of 238U and never a particle with enriched 235U. The bulk of the particle consisted of material consistent with combustion of heavy fuel oil. Analysis of wind trajectories and particle dispersion model results show that the particle could have originated from a variety of areas across Asia. The source of such a particle is unclear, and the particle is described here in case it indicates a novel source where enriched uranium was dispersed.
 

February 18, 2018 Posted by | Fukushima 2018 | , | Leave a comment

Mysterious and ‘HIGHLY UNUSUAL’ radioactive substance detected in Alaska

Feb 15, 2018
Alaska-919396.jpg
SCIENTISTS have discovered an atmospheric aerosol particle enriched with uranium in Alaska which is used in nuclear fuel and bombs – and no-one can explain why the substance is there or how it arrived.
Experts from the US National Oceanic and Atmospheric Administration said they have found a “highly unusual aerosol particle containing a very small amount of enriched uranium” .
The substance with the uranium-235 have been found for the first time in 20 years of searches, say experts.
This particle can fuel nuclear reactions, are used in nuclear power plants, can damage organic material and cause mutations that lead to cancer.
The scientists said: “The bulk of the particle probably came from combustion of heavy fuel oil.
“The particle was encountered when we were making no special attempt to sample radioactive material.
“We don’t know the source for this particle. It may indicate a novel source where enriched uranium was dispersed.”
They believe the particle could have come from across Asia and was brought to the spot by the winds.
The researchers say the the sample was “definitely not from a natural source” but could have come from burnt nuclear fuel.
The scientists made the findings when their research plane was flying over the Aleutian Islands in 2016 and detected the uranium floating about four miles above Alaska’s far-western island chain.
Leader of the study, Dan Murphy, said to Gizmodo: “It’s not a significant amount of radioactive debris by itself. “But it’s the implication that there’s some very small source of uranium that we don’t understand.
One of the main motivations of this paper is to see if somebody who knows more about uranium than any of us would understand the source of the particle.”
The full findings have been published in the Journal of Environmental Radioactivity.
After the disaster at the Fukushima nuclear power plant in 2011 in Japan, experts became concerned about radiation impacts in Alaska as three reactors melted down. However, as the particle was found in 2016, the two are unlikely to be linked.

February 18, 2018 Posted by | Fukushima 2018 | , | Leave a comment

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