New video from Fukushima Daiichi
New video from inside a crippled Fukushima Daiichi nuclear reactor shows possible melted fuel.
http://www.ntv.co.jp/englishnews/society/new_video_from_fukushima_daiichi/
Oceanic dispersion of Fukushima-derived radioactive cesium: a review
This paper focuses on the radioactive Cs in seawater and summarizes estimates of the total amount of released radioactive Cs from the FNPP site, spatio–temporal changes in the concentrations of 134Cs and 137Cs not only off the coast of Fukushima and adjacent prefectures, but also in the North Pacific, and adjacent seas such as Japan Sea, East China Sea, based on measurement results and simulation models published during 4 years since the FNPP accident.
14 decembre 2016
Oceanic dispersion of Fukushima-derived radioactive cesium: a review
Abstract
This review summarizes the more than 70 papers published during the 4 years since the Fukushima Dai-ichi nuclear power plant accident that occurred on 11 March 2011, and details the radioactive cesium dispersion pattern in the North Pacific and adjacent seas. The total amount of Fukushima-derived radioactive cesium released into the North Pacific via atmospheric deposition and direct release, spatial and temporal changes in the Pacific coast around the accident site, and the concentration levels of radioactive cesium around the Japanese Islands, not only the Pacific coast but also in adjacent seas, such as Japan Sea, East China Sea are summarized. Based on observational data mostly obtained during 2 years since the accident, and simulation results, oceanic dispersion of radioactive cesium in the entire area of the North Pacific is described. The Fukushima-derived radioactive cesium dispersed eastward as surface water and extended to the eastern side of the North Pacific in 2014, and was also observed via a southward intrusion to subsurface waters as Subtropical Mode Water and Central Mode Water. The radioactive cesium movement related to mode water is important in terms of the circulation of cesium into the ocean interior. Some new technologies and techniques concerning emergency monitoring of radioactivity in the ocean environment are also reported, the effectiveness of which has been demonstrated by use in relation to the Fukushima accident.
Introduction
On 11 March 2011, the Great East Japan Earthquake (Mw 9.0) occurred at the plate boundary off the coast of Tohoku, northeastern Japan. A huge tsunami was generated and caused 15 729 fatalities and 4539 missing in the Hokkaido, Tohoku and Kanto regions (The National Police Agency, as of 24 August 2011). Preliminary surveys reported tsunami waves with run-up heights exceeding 30 m (Mori et al., 2011). The tsunami also hit the Fukushima Dai-ichi Nuclear Power Plant (FNPP) sites located at 37˚25’N, 141˚02’E, and a loss of electric power at FNPP resulted in overheated reactors and hydrogen explosions. Radioactive materials were then released into the ocean through atmospheric fallout (such as aerosols and precipitation) and as direct releases (controlled releases related to safety issues at FNPP) as well as uncontrolled leaking of the heavily contaminated coolant water (Buesseler et al., 2011; Chino et al., 2011; Takemura et al., 2011). This accidental release of anthropogenic radionuclides (mostly iodine-131, cesium-134 and -137; 131I, 134Cs and 137Cs) resulted in severe elevations of these radionuclides in fisheries products in the coastal areas of Fukushima and adjacent prefectures (Buesseler, 2012; Yoshida and Kanda, 2012; Wada et al., 2013; Nakata and Sugisaki, 2015). Owing to its relatively long half-life (2.07 years for 134Cs and 30.07 years for 137Cs), the evaluation of these radioactive Cs isotopes in the marine environment is important for addressing risks to both marine ecosystems and public health through consumption of fisheries products. Generally, cesium is a conservative element and mostly occurs in the dissolved phase in the marine environment. The concentration of radioactive cesium in marine organisms is strongly affected by its concentration in the surrounding seawater. Actually, temporal changes in radioactive Cs concentrations of many pelagic fish species in the near coastal area off Fukushima and adjacent prefectures were associated with those in seawater after the FNPP accident (e.g., Wada et al., 2013; Takagi et al., 2015; Morita et al., unpublished data). Kaeriyama et al. (2015) and Morita et al. unpublished data revealed the time-lagged temporal changes in radioactive Cs in organisms (zooplankton and Pacific saury) and seawater under non-steady-state conditions after the FNPP accident, and showed that the concentration ratios in these organisms had been elevated when compared with those before the FNPP accident. With regard to zooplankton, Baumann et al. (2015) discussed the possible uptake of Fukushima-derived radioactive Cs from phytoplankton dominated suspended particles. As a consequence, radioactive Cs would be transferred to the higher trophic level not only via surrounding seawater but also by prey-predator interactions in the pelagic ecosystem. Shigenobu et al. (2014) reported the radioactive Cs concentrations of fat greenling (Hexagrammos otakii) caught off the coast of Fukushima Prefecture, and reported two outlier specimens caught in August 2012 and May 2013 which had ambiguously high 137Cs concentrations of more than 1000 Bq/kg-wet. Probability analysis indicated that the two outlier fat greenlings had migrated from the port of FNPP. In the port of FNPP, extremely high 137Cs concentrations were reported from Japanese rockfish (Sebastes cheni), brown hakeling (Physiculus maximowiczi) and fat greenling (H. otakii) caught during January and February 2013 (Fujimoto et al., 2015). The maximum concentration of 137Cs (129 kBq/kg-wet) was detected from fat greenlings. Wada et al. (2013) with the corrigendum (Wada et al., 2014) summarized the monitoring results of radioactive Cs concentrations in fisheries products from Fukushima Prefecture and revealed time-series trends. Clear trends include a slower decrease of radioactive Cs in demersal fish compared to pelagic fish as well as spatial heterogeneity; specimens sampled in the area south of FNPP tended to have higher concentrations of radioactive Cs than those caught in the area north of FNPP. Sohtome et al. (2014) reported the time-course trends in concentration of radioactive Cs in invertebrates in the coastal benthic food web near the FNPP. The difference in decreasing trends observed within the organisms and the concentrations of radioactive Cs in some of the sea urchins (Echinocardium cordatum and Glyptocidaris crenularis) were clearly affected by the contaminated sediments taken into their digestive tract.
This paper focuses on the radioactive Cs in seawater and summarizes estimates of the total amount of released radioactive Cs from the FNPP site, spatio–temporal changes in the concentrations of 134Cs and 137Cs not only off the coast of Fukushima and adjacent prefectures, but also in the North Pacific, and adjacent seas such as Japan Sea, East China Sea, based on measurement results and simulation models published during 4 years since the FNPP accident.
Total Amount of FNPP–Released Radioactive Cesium
Information on the total amount of the FNPP-released radioactive Cs into the North Pacific is critical information to enable effective monitoring and resource management. However, despite its importance, estimation of atmospheric deposition is complex due to lack of the observational data in the oceanic environment. The activity ratios of 134Cs/137Cs, decay corrected to March–April 2011, were reported to be almost 1.0 for the entire North Pacific (e.g., Buesseler et al., 2011, 2012; Kaeriyama et al., 2014). This ratio means an equivalent amount of 134Cs and 137Cs was released into the ocean. Under the limitation of data concerning not only the amount of radioactive Cs in aerosols but also on precipitation in the North Pacific, estimation of atmospheric deposition remains a source of considerable uncertainty (5–15 PBq of 134Cs and 137Cs; 1 PBq = 1015 Bq, Table 1). In contrast, the direct release of radioactive Cs (134Cs and 137Cs) into the ocean as uncontrolled leaking of the heavily contaminated coolant water is well estimated as approximating the value of 3.5 PBq, with the exception of Bailly du Bois et al. (2012) and Charette et al. (2013) (Table 1). Dietze and Kriest (2012) discussed the possible overestimates by Bailly du Bois et al. (2012) as a result of methodological issues. Charette et al. (2013) estimated the direct release inventory from the observational data of radioactive Cs with radium isotopes in May–June 2011, and no atmospheric deposition was assumed. Their estimates of direct releases may be included in the atmospheric deposition. Tsumune et al. (2012) clearly showed that direct releases started on 26 March 2011 using 131I/137Cs activity ratios, which varied much more before 26 March 2011 when the atmospheric deposition was the major source. The most recent estimations have revealed that 3–4 PBq of 134Cs and 137Cs were directly released into the ocean and 12–15 PBq of 134Cs and 137Cs were deposited on the surface seawater in the North Pacific (Aoyama et al., 2015a).
Table 1. Estimated total inventory of 137Cs (PBq) in the North Pacific in 2011
Figure 1.
Schematic view of current system: (a) in the North Pacific and (b) around the Japanese Islands. Solid lines indicate surface current and dashed lines indicate the movement of mode waters. FNPP: Fukushima Dai-ichi Nuclear Power Plant; STMW: Subtropical Mode Water; CMW: Central Mode Water. Based on Kumamoto et al. (2014); Oka et al. (2011, 2015); Talley (1993) and Yasuda (2003) [Colour figure can be viewed at wileyonlinelibrary.com].
Read more : http://onlinelibrary.wiley.com/doi/10.1111/fog.12177/full
Columban missionary backs bishops against nuclear industry after harrowing visit to Fukushima clean-up
Evacuated: An evacuee rests in a gymnasium serving as an evacuation centre in Yamagata, Japan, in March 2011. Residents from the vicinity of Fukushima Dai-ichi nuclear power plant were sheltered at the gym, as officials and workers struggled to contain the situation at the badly damaged nuclear facility.
A COLUMBAN missionary has witnessed a massive contamination clean-up in the Japanese region surrounding Fukushima, where a 2011 earthquake and tsunami triggered a nuclear power plant meltdown.
Fr Paul McCartin, recently visited the Fukushima region, six years after the nuclear disaster, and ahead of a government evacuation order being lifted at the end of this month, which will allow people to return home.
Arriving by bullet train at the town of Kouriyama, 60km west of Fukushima Number One Nuclear Power Plant, Fr McCartin said the first surprise was the large radiation monitor in front of the station.
“Over the next three days I saw similar monitors in cities, beside country roads and along expressways,” Fr McCartin, the Columban Justice, Peace and the Integrity of Creation co-ordinator in Japan, said.
He has worked in Japan since 1979 and visited the Fukushima last September.
“I had taken face masks but our guides gave us better ones,” he said.
“We were told to make sure we washed our hands and around our mouths before eating.
“I was given a small radiation monitor to wear around my neck.
“Over the two-and-a-half days I was exposed to 8.1 micro Sieverts, an ‘acceptable’ amount.”
The Sievert is a measure of the health effect of low levels of ionising radiation on the human body.
As Fr McCartin drove through the Fukushima countryside, he found houses barricaded, roads closed and warnings from officials amidst a massive clean-up.
“I was restricted. There were roadblocks with security personnel,” he said.
“I was advised not to hike in Fukushima as there is a lot of radiation in the mountains, especially at the base of mountains as rain washes it down.
“Buildings and roads are being washed down, and contaminated soil and vegetation being removed.”
He said topsoil to a depth of five centimetres was being removed and replaced with soil from unaffected areas.
“There are large collections of industrial waste bags all over the place. There must be hundreds of thousands, if not millions,” he said.
At the end of March, Japan is set to lift evacuation orders for parts of Namie, located 4km from the wrecked Fukushima Daiichi nuclear plant, as well as three other towns.
More than half of Namie’s former 21,500 residents have decided not to return.
Namie, and other nearby centres are now ghost towns, dilapidated, and for many, they conjure horrific memories.
Tsunami damage: Facilities near the seawater heat exchanger building at Tokyo Electric Power Company’s Fukushima Daini nuclear power plant Unit 3 reactor on April 2, 2011, days after an earthquake and tsunami hit the area in north-east Japan.
A government survey showed last year, there were lingering concerns over radiation and the safety of the nuclear plant, which is being decommissioned.
Beyond radiation risks, an unexpected nuisance looms – hundreds of wild boars have descended from surrounding hills and forests into the deserted towns.
The creatures have roamed across the radioactive contaminated region.
In Namie, wild boars occupy the empty streets and overgrown backyards foraging for food.
In the nearby town of Tomioka, local hunters have captured an estimated 300 boars.
Following his visit last September, Fr McCartin is concerned about the spread of contaminated material.
“Low-level waste is being recycled,” he said.
“Highly contaminated waste is being burned.
“So far only one per cent of high-level waste has been burned.
“More incinerators are being constructed.
“Contaminated waste is being used in the wall being built along the shore to prevent another tsunami hitting the area.
“In fact, there is so much radioactively contaminated waste that local facilities can’t handle it, so ‘low-level waste’ is being transported to many distant places for disposal.
“Contaminated fishing gear and nets are being disposed of in the town where I live.
“In this way, radiation is being spread to many parts of the country.
“It would seem to make sense to keep it where it is and avoid unnecessarily contaminating the rest of the country.”
Fr McCartin said the Japanese media was muzzled from challenging the government on Fukushima and the hazards of nuclear power.
The efforts of individual journalists reporting on the issue were often dismissed.
“A Catholic in Yokohama told me last year that after his daughter wrote a piece on Fukushima for the newspaper she works for, her boss told her, ‘No more on Fukushima’,” he said.
“The government has threatened to shut down any media organisation that publishes something the government doesn’t like.
“In the last year or so three forthright and prominent media personalities have been sacked or not had their contracts renewed.”
Fr McCartin said he supported a call by Japanese Catholic bishops to abandon the nuclear power industry.
“I believe that if the government transferred a small fraction of the trillions of dollars it throws at the nuclear industry to the renewable energy industry, the country would be awash in safe energy in a very short time,” he said.
State to appoint Tepco’s new president
TEPCO to reshuffle top managers
Some big changes are in store for the boardroom of the company that operates the Fukushima Daiichi nuclear plant. A planned reshuffle at Tokyo Electric Power Company Holdings is aimed at speeding up work at the crippled plant and moving ahead with business reforms.
The government owns a majority of the shares in TEPCO Holdings, giving it effective control. The company faces a decades-long task of decommissioning the melted down reactors and paying compensation.
Sources say government officials are now putting the finishing touches on a plan to replace Chairman Fumio Sudo. Taking his place will be Takashi Kawamura, chairman emeritus of electronics-maker Hitachi.
TEPCO Holdings President Naomi Hirose will become vice chairman and he’s going to focus on efforts to help revitalize Fukushima Prefecture.
Tomoaki Kobayakawa, who heads the group’s retail unit, will be taking over his job.
TEPCO plans to hold a board meeting as early as Friday to formally approve the new lineup.
https://www3.nhk.or.jp/nhkworld/en/news/20170327_13/
State taps director Kobayakawa to become Tepco’s next president
The government plans to appoint Tomoaki Kobayakawa, a director on the board of Tokyo Electric Power Company Holdings Inc., as president of the nationalized utility, it was learned Sunday.
Kobayakawa, 53, is president of Tepco Energy Partner Inc., a retail subsidiary.
The government plans to have Tepco President Naomi Hirose, 64, step aside to take the post of vice chairman so he can concentrate on decommissioning the disaster-stricken Fukushima No. 1 nuclear plant and compensating the people and businesses affected by the March 2011 triple core meltdown, informed sources said.
To replace Tepco Chairman Fumio Sudo, 76, the government has already asked Takashi Kawamura, 77, honorary chairman of Hitachi Ltd.
Tepco plans to adopt the appointments this month. The new management team is expected to be launched after a shareholders meeting in June.
Tepco is expected to invite Shoei Utsuda, 74, who advises trading house Mitsui & Co., and Kazuhiko Toyama, 56-year-old chief executive officer of Industrial Growth Platform Inc., as outside board members.
By revamping Tepco’s top management, the government hopes to speed up its reform mainly through operational realignment that may involve other companies. This is aimed at improving its competitiveness and raising funds to finance the enormous costs of dealing with the man-made nuclear accident triggered by the March 2011 earthquake and tsunami, according to the sources.
The leaders of Tepco’s subsidiaries are also expected to be replaced.
With Kobayakawa at the helm, the holding company plans to rejuvenate its management team and promote rehabilitation under the leadership of Kawamura, who engineered the drastic recovery of Hitachi’s earnings.
The new Tepco team will face the challenge of balancing work to address the consequences of the world’s worst nuclear disaster since Chernobyl and boosting its earnings capacity.
Tepco plans to draw up soon a new business reconstruction program calling for, among other steps, the integration of its electricity transmission and nuclear businesses with other companies.
Japan Political Pulse: The truth about Fukushima nuclear disaster compensation
Of the unknown number of children who have been bullied for being from Fukushima Prefecture, where a nuclear disaster is still ongoing at a power station six years since its outbreak, one boy who evacuated to Yokohama was bullied and extorted by his classmates of 1.5 million yen in total.
Now in his first year of junior high school, the boy wrote when he was in sixth grade, “My classmates said, ‘You get compensation, right?’ That annoyed me, but I was frustrated with myself for not standing up against them.”
Ironically, news reports say that because the family voluntarily evacuated from Fukushima Prefecture, they are not eligible for the high levels of compensation from the operator of the stricken nuclear plant, Tokyo Electric Power Co. (TEPCO), that some victims are entitled to receive.
Those who evacuated from Fukushima Prefecture due to the nuclear crisis can be largely categorized into two groups. The first are those who were forced to leave their homes under evacuation orders from the central government, because they lived in areas where annual cumulative radiation levels exceeded 20 millisieverts, or otherwise faced extenuating circumstances as determined by the state. Such people receive a certain lump sum from TEPCO as compensation.
The second group comprises people who lived in areas with radiation levels that did not prompt government evacuation orders, but who evacuated voluntarily out of concern for the health of themselves and their children. As a general rule, these people are not eligible for compensation from TEPCO.
In the case of forced evacuations, TEPCO conducts individual interviews with evacuees to assess the value of their property and homes. But this is strictly to compensate for the assets that people have lost.
What has often attracted attention but remains commonly misunderstood, is the monthly 100,000 yen per person that evacuees are said to be receiving as compensation for emotional suffering. Those who evacuated without orders to do so from the government are not eligible for this, either.
Meanwhile, the provision of compensation for emotional suffering to state-ordered evacuees whose homes are in areas where evacuation orders are set to be lifted will be stopped in March 2018. Whether or not such evacuees will return to their homes in Fukushima Prefecture once the no-go orders are lifted, they face the harsh reality that they will be cut off from government assistance. The government is rushing to rebuild infrastructure, and appeal to the world that they are lifting evacuation orders. But whether to return or to relocate is a difficult decision, especially for families with children.
People who evacuated from Fukushima Prefecture have not only been exposed to radiation, but to prejudice and misunderstanding regarding compensation that they may or may not have received.
The false rumor that compensation recipients are enjoying the high life from compensation payments has spread. We can’t deny that some probably indulged in the momentary influx of money and bought property or a fancy car. But because of that, the internet has been teeming with rumors that compensation recipients are tax thieves or calls for them to go back where they came from. And there’s no doubt that such a backdrop of online defamation and scandalmongering emboldened the children who bullied the boy in Yokohama.
The truth is, the family of the boy in Yokohama had evacuated Fukushima Prefecture voluntarily. They received a little over 1 million yen from TEPCO, but the parents said in an interview with an NHK new program, Close Up Gendai, that the money was put toward rebuilding their lives. Voluntary evacuees are exempt from paying rent due to the Disaster Relief Act, but many must restart new lives amid unstable finances.
The abovementioned boy moved to Yokohama with his family when he was in second grade. Shortly thereafter, classmates called him by his name, with the word for “germs” added on to the end. He soon found himself the victim of physical abuse such as hitting and kicking, and once he reached fifth grade, classmates demanded he give them money.
“I was so scared I didn’t know what to do,” the boy wrote. He stole from his parents and gave away a total of 1.5 million yen.
His parents, and other parents of children at the school who realized that something was going on, alerted the school. The school conducted an investigation, but took the bullies’ claims that the boy had given them money willingly at face value, and did nothing to remedy the situation for two years.
I, too, only learned the truth about the case just recently, but I believe the school’s misguided judgment was likely based on ignorance and prejudice toward compensation given to Fukushima Prefecture evacuees.
The boy’s mother had been traveling back and forth between Yokohama and Fukushima. He knew how much his parents were struggling, so he remained silent about the bullying.
What moved the case into a new direction were notes the victim had written in the summer of sixth grade. A message calling on bullying victims not to kill themselves also written by the now first-year junior high school student who attends an alternative school, was also released to the public.
Compensation is given to some victims of the Fukushima nuclear disaster. But there is still too little compassion toward and understanding of the various misunderstandings, discrimination and divisions that disaster victims face.
http://mainichi.jp/english/articles/20170326/p2a/00m/0na/003000c
TEPCO to delay seeking end to state control by 2 years to FY 2019
Tokyo Electric Power Company Holdings Inc. will delay a decision on whether to seek an end to its state control by about two years to fiscal 2019 amid ballooning costs stemming from the 2011 Fukushima nuclear disaster, an outline of its new business plan showed Wednesday.
The move is another sign the utility is struggling to revive its business even after receiving a capital injection of 1 trillion yen ($9 billion) from the government in 2012 to bolster its financial standing. But disaster cleanup costs have continued to rise, with the latest estimate reaching 22 trillion yen.
Under its latest business turnaround plan, which will be the third major revision since the first one was formulated in 2011, TEPCO aims to realign or integrate its nuclear and power transmission and distribution businesses with other utilities to improve its profitability. But it is uncertain whether business will get back on track as planned, with other utilities cautious about such tie-ups.
Nuke watchdog critical as robot failures mount at Fukushima plant
Some Nuclear Regulation Authority members are skeptical of continuing to send robots into reactors in the crippled Fukushima No. 1 nuclear plant to collect vital data on the locations of melted nuclear fuel and radiation levels.
These regulators are increasingly calling for a new survey methodology after recent investigations utilizing robots controlled remotely generated few findings and were quickly terminated.
“We should come up with a method that will allow us to investigate in a short period of time and in a more sensible way,” said a senior member of the NRA, the government watchdog.
The suggestion followed the failure of the latest probe from March 18 to March 22 in which a robot was sent in the No. 1 reactor to ascertain the location of fuel debris, information crucial to preparing for the decommissioning.
Tokyo Electric Power Co., the operator of the plant, said on March 23 the robot was unable to deliver a camera to planned spots from where images of nuclear fuel debris could be taken.
The utility cited the piping and deposits of what looked like sand accumulating on the piping as impediments that hindered the robot surveyor’s path.
The survey was designed for the robot to reach numerous locations inside the No. 1 reactor to determine the location of nuclear fuel debris and their radiation levels.
The lower part of the reactor’s containment vessel is submerged in water where deposits of fuel debris are believed to reside below the surface after melting through in the 2011 nuclear disaster, triggered by the Great East Japan Earthquake and tsunami.
At one location, the robot succeeded in placing a camera, which is combined with a dosimeter, to a depth 0.3 meter from the containment vessel floor.
The probe measured underwater radiation levels from 3.0 to 11 sieverts per hour during the five-day survey. But it was unable to take images of the debris in the water.
TEPCO and the government hope to start removing molten nuclear fuel from 2021. But they have yet to collect information on the location, amount and condition of the melted fuel.
In a survey of the No. 2 reactor in February, a robot became stuck in deposits and other debris after traveling only 2 meters inside.
Surveyor robots for the No. 1 through No. 3 reactors have been developed by the International Research Institute for Nuclear Decommissioning since 2014, a project costing 7 billion yen ($62 million) by the end of March 2018.
It takes time to develop such multifunctional robots, but the surveys centering around the robots so far have failed to produce meaningful results.
No survey has been conducted at the No. 3 reactor.
Japan’s TEPCO looking for international help to clean up Fukushima nuclear plant
The call for partners follows two robotic failures during cleanup efforts at the plant last month
TOKYO—The Tokyo Electric Power Co. has issued a call for partners to help it decontaminate and decommission the Fukushima Daiichi Nuclear Power Station.
The nuclear power plant was seriously damaged in 2011 by a tsunami triggered by a powerful offshore earthquake. The subsequent reactor meltdowns led to the release of radioactive material, which remains at high levels inside the plant six years after the accident.
The call for international collaboration follows two robotic failures inside Fukushima’s Unit 2 reactor last month. One cleaning robot was pulled out of the plant prematurely due to higher-than-expected radiation, while another had to be abandoned inside after its crawling function failed.
Earlier this month, Naohiro Masuda, the head of decommissioning at the plant said engineers will need to think ‘out of the box’ to develop robots capable of surveilling the plant.
TEPCO said it is particularly interested in consultants with on-site recycling methods that could reduce the amount of radioactive waste being generated—though it noted there are many other areas of expertise it’s interested in as well.
More details about the collaboration program are available here.
TEPCO is looking for partners that would realize innovative values and solutions to critical social issues.
Through challenging ourselves with new technology, dealing with various businesses, and making even greater use of the big data stored and created by TEPCO, we contribute to society’s development by creating new value for the lives and businesses of consumers and business people.
Co-creation will open new doors.
By partnering with you, we will be able to tackle issues we could not before. It is our mission to create better future by openly cooperating with everyone as we move forward.
The Robot Probe Cannot Confirm Where is the Melted Fuel of Unit 1
Tokyo Electric Power Company announced on February 23 that it had completed a robot probe survey lasting five days in the reactor containment vessel of Fukushima Daiichi nuclear power plant Unit 1.
Its goal was to confirm the whereabout of the melted nuclear fuel, but it was blocked by piping and could not put the camera in athe place where nuclear fuel could be seen.
Information necessary for taking out the nuclear fuel to decommission the reactor remains inadequate, and some voices began to question the robot conducted investigation method.
During the 5-day survey, there was also a point where the measuring instrument with an camera and a radiation dosimeter integrated together was hung up in a range from 0 to 3 meters from the bottom of the containment vessel, pipes and debris blocking its path in many points. The radiation dose in the water is from 3.0 to 11 Sv. Per hour. It was not possible to directly check the melted nuclear fuel.
TEPCO and the country are facing the decommissioning of a furnace …
Tepco robot failed to capture images of melted fuel in reactor 1
A photo taken by a robot on Wednesday shows an underwater image of water pool on the bottom of the containment vessel of the reactor 1 at the Fukushima No. 1 plant
Tokyo Electric said Thursday that it failed to get any photos of potential fuel debris during a five-day probe of the primary containment vessel at reactor 1 of the Fukushima No. 1 power plant.
Tokyo Electric Power Company Holdings Inc., however, stressed that the investigation was worthwhile because its robot was able to take underwater images in the pool of water at its bottom and gauge its radiation level, which will help it estimate where the melted fuel lies.
The monstrous tsunami of March 11, 2011, tipped reactors 1, 2 and 3 into core meltdowns. The molten fuel rods then penetrated their pressure vessels before apparently dropping to the bottom of the giant containment vessels.
There is about a 2.5-meter deep water pool at the bottom of the primary containment vessel of reactor 1, and Tepco believes most of its melted fuel rods fell into it. Thus the main mission of the robot investigation this time was to capture underwater images.
The robot traversed gratings set up several meters above the vessel’s bottom and lowered a wire with a camera and dosimeter on its tip at 10 locations in the water.
Yet none of the images disclosed by Tepco showed anything resembling fuel debris, while parts of machinery, such as a valve, were captured.
When the robot dangled the camera on spots where Tepco thought there was a higher probability of locating the fuel, it instead found a 90-cm pile of sediment.
Tepco spokesman Yuichi Okamura said the sediment is probably not fuel debris, given the relatively low radiation readings, which ranged from 5.9 to 9.4 sieverts per hour.
Although the readings indicate extreme danger to people, Okamura said the readings would have been much higher had they been melted fuel rods. He said Tepco had no idea what the sediment is but added that there was a possibility it was covering the fuel.
According to Okamura, radiation readings get weaker by a hundredth if blocked by a meter of water. Since the robot detected readings from 5.9 to 9.4 sieverts per hour about 90 cm above the pool’s bottom, there might be something down there emitting strong radiation.
Tepco plans another investigation this month to pick up samples of the sediment.
While no fuel debris was recognized, Okamura said Tepco would review the data and analyze it further. By comparing radiation readings from various locations, the utility might be able to roughly pinpoint where the melted rods lay, he said.
He added that it was an achievement that the robot lasted for five days in the deadly radiation and that Tepco was able to retrieve it.
Yakuza hide IDs to secretly thrive in Tohoku’s disaster zones
A gang leader says he effectively controls several companies involved in rebuilding projects in the Tohoku region.
A company has been busy dispatching temporary workers for the Herculean task of rebuilding lives in the disaster-hit Tohoku region. But the company’s most important job for survival is to conceal any evidence of its true, sinister nature.
“This is a company I established,” said the leader of a gang affiliated with an organized crime syndicate based in western Japan. “I made sure that no signs of any possible association with yakuza organizations were left.”
Although the National Police Agency has tried to prevent gangsters from cashing in on the triple disaster that struck in March 2011, yakuza groups appear to be thriving in the Tohoku region and extending their reach.
Their companies not only dispatch workers and lease heavy machinery, but they are also involved in more traditional services, such as providing prostitutes and dealing drugs, with workers at the stricken Fukushima No. 1 nuclear power plant and other sites as potential targets.
Police say there is little they can do to shut down the yakuza activities.
The gang leader’s company, which was set up in a city in the Kanto region last December with a start-up cost of 5 million yen ($45,000), appears innocent on the surface.
The president named on company’s registry has no ties with organized crime, and the true leader and members of his family and group are not listed as directors.
The gang leader said he also has effective control over other companies that send workers to contractors involved in an array of projects, including decontaminating areas or dismantling abandoned houses.
“I make millions of yen a month, including about 100,000 yen per contractor and siphoning from workers’ daily allowances,” the gang leader proudly said.
Twenty days after the Great East Japan Earthquake and tsunami struck on March 11, 2011, triggering the nuclear disaster, the NPA directed all prefectural police departments to keep gangsters away from the reconstruction projects.
Similar requests were made to the construction industry, Tokyo Electric Power Co., operator of the nuclear plant, government ministries and agencies and local authorities.
But a number of yakuza organizations are now behind the companies involved in the rebuilding projects.
In some cases, they gain control of legitimate but cash-strapped companies by providing funds.
One crime syndicate reportedly advises umbrella groups on “how to set up a company by keeping others from becoming suspicious.”
Police officials dealing with crime syndicates acknowledge that it is “practically impossible” to thoroughly check for possible ties between subcontractors and gangster organizations.
In some cases, a single project is outsourced to more than 10 subcontractors.
“All we can do is check whether individuals connected to underground groups are listed in the registration papers,” a police official said.
Police say they can confirm a yakuza connection only after they scrutinize the company directors’ circle of friends and acquaintances and other relevant data.
Although anti-yakuza ordinances are believed to be depleting the finances of mobsters around Japan, the crime syndicates are systematically running operations in the Tohoku region as if it’s business as usual.
One leader of an underground group said he was ordered by its parent organization “not to lag behind others” in exploiting potentially lucrative projects.
After the 1995 Great Hanshin Earthquake, the parent organization began asking all groups under its umbrella to give “regular reports” about rental agents of heavy machinery, dump trucks and other equipment indispensable in rebuilding projects on their turfs.
The move was apparently designed to prepare for the day when they needed to quickly obtain as much machinery as possible.
That day arrived on March 11, 2011.
“There is a huge demand for such equipment in a disaster,” a former senior member of a gang group said. “We can lease it at our asking price.”
Crime organizations have also seen a potentially lucrative market in the predominantly male work force at the Fukushima nuclear plant and other reconstruction projects in the Tohoku region.
“I came to Fukushima to have fun as an adult,” said an entry, presumably by a female, on a dating site for men. “I am looking for somebody I can meet in Nihonmatsu,” said another, referring to a city in Fukushima Prefecture.
The website, set up by the head of a gangster organization in the Kanto region, targets workers at the stricken nuclear plant and elsewhere.
The gang leader said he takes women who have experience in the sex industry to disaster-stricken areas in his car and stays there for several days.
He sends the women to love hotels or the clients’ vehicles, depending on the customers’ requests. One encounter costs about 30,000 yen, he said, adding that 60 percent goes to the woman while he pockets the remainder.
“I am in fierce competition with other underground groups in this line of business,” he said. “But I can earn at least 3 million yen a month.”
Drug deals are also said to be at play in the disaster zone.
“I have seen and heard about the use and deals in stimulant drugs at the plant,” recalled the leader of a gang group based in eastern Japan who works at the Fukushima nuclear complex.
He was assigned to the plant just after a hydrogen explosion took place there.
TEPCO and Fukushima prefectural police said they are not aware of any drug use at the plant.
However, a plant worker in his 30s died at a hospital in August 2015 after he complained of sickness on a bus taking him from the nuclear plant.
He turned out to be a gang member, according to police. His urine sample showed possible signs of stimulant drug use, but his cause of death was not determined.
Between 2011 and 2016, police have busted underground groups involved in rebuilding projects in 101 cases.
Fraud accounted for 54 cases. They were primarily gangsters pretending to collect donations for disaster victims or mobsters involved in illicit borrowing.
Twenty-five cases concerned dispatches of workers to assignments that they were not allowed to perform.
In one case, a senior member of a group affiliated with the Sumiyoshi-kai, one of the largest crime syndicates in the nation, was arrested in May 2012 on suspicion of illegally sending workers to the Fukushima plant. Police uncovered that the mobster received about 40 million yen between 2009 and 2011 by sending workers to nuclear plants and thermal power plants across the country.
Visualizing nuclear radiation: Team images gamma rays to help decontaminate Fukushima
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.”
https://phys.org/news/2017-03-visualizing-nuclear-team-images-gamma.html#jCp
Deadly nuclear radiation levels detected in Fukushima
Extremely high radiation levels were detected using cameras and robots in tainted water inside a reactor containment vessel at the Fukushima No. 1 nuclear power plant, Japan Times reported Tuesday, citing Tokyo Electric Power Company Holdings Inc. (Tepco).
The latest readings, taken six years after the Fukushima nuclear meltdown, showed 11 sieverts per hour, according to Japan Times. It is the highest radiation level detected in water inside the containment vessel and is extremely dangerous. Sievert is a unit measurement for a dose of radiation. One sievert is enough to cause illness if absorbed all at once, and 8 sieverts will result in death despite treatment, according to PBS who relied on data from multiple sources including United States Nuclear Regulatory Commission and MIT’s Nuclear Science and Engineering department.
Following a major earthquake on March 11, 2011, a 15-metre tsunami disabled the power supply and cooling of three Fukushima reactors, causing a nuclear accident. Tepco, who operated the plant and has been tasked with cleaning up the worst nuclear incident, since the 1986 Chernobyl disaster in the former Soviet Union, has been some problems of late in its cleanup operation.
Recently, an exploratory robot malfunctioned and died after being sent inside reactor 2, in mid-February, due to exposure to “unimaginable” levels of radiation, close to 650 sieverts per hour. The previous highest recorded level was 73 sieverts per hour. Following the incident, Naohiro Masuda, president of Tepco’s Fukushima Daiichi Decommissioning project, told reporters the company had to rethink its methods in order to examine and extract the hazardous material stuck in the plant’s second reactor.
“We should think out of the box so we can examine the bottom of the core and how melted fuel debris spread out,” Masuda said, according to the Japan Times.
Tepco has been attempting to locate melted fuel which leaked from the reactor’s pressure vessel and is believed to have settled at the bottom of the containment vessel that holds the contaminated water. So far, no such debris has been found, and Tepco decided to extend the survey by one day through Wednesday.
A robot sent by the company on March 20 reached the bottom but was unable to locate the melted fuel due to some pipes that blocked its view. But it was able to take pictures of what appeared to be sand piling up near the pipes. The radiation readings near them were 6.3 sieverts per hour.
“Judging from the radiation level, there is a high possibility that what is piling up on the pipes is not nuclear fuel,” a Tepco official said, according to the Asahi Shimbun.
Cleaning up the plant may take an estimated 40 years and cost an estimated 21.5 trillion yen ($189 billion), according to the Guardian.
https://www.rawstory.com/2017/03/deadly-nuclear-radiation-levels-detected-in-fukushima/
Lethal radiation levels but no melted fuel found in Fukushima reactor water
The Unit 2 reactor building at Tokyo Electric Power Co.’s Fukushima Daiichi nuclear power plant.
The level of radiation was measured by a special robot on Sunday at a point about 30cm (one foot) from the bottom of the containment vessel of Reactor 1, the Japan Times reported on Tuesday.
The current radiation level is 11 sieverts per hour, the highest detected in water inside the containment vessel. A person exposed to this amount of radiation would likely die in about 40 minutes, the Japan Times reports.
Sunday’s probe also revealed sandy substances building up at the bottom of the vessel. Tokyo Electric Power Company Holdings (TEPCO) officials, however, dismissed the idea that it might be melted nuclear fuel.
Experts have been looking for the melted fuel, which they believe has been accumulating in tainted water.
In March 2011, a 9.1 earthquake and the 15-meter tsunami that followed disabled the cooling system of Fukushima’s three reactors, causing the worst nuclear incident since the 1986 Chernobyl incident in Ukraine.
TEPCO, which operates the crippled power plant, has been obliged to deal with the consequences of the incident.
In February, a robot sent to explore Reactor 2 broke down because of the “unimaginable” levels of radiation, close to 650 sieverts per hour. This was the first time a robot entered this reactor since the plant’s meltdown in 2011.
Previously, the highest radiation level was recorded one year after the disaster and went up to 73 sieverts per hour.
TEPCO has promised extract the hazardous material stuck in the plant’s second reactor, its president Naohiro Masuda said, according to the Japan Times.
In December, TEPCO nearly doubled the estimated cost for the Fukushima clean-up to $188 billion.
A zone of more than 300 square miles around the plant is currently uninhabitable due to the continuing radiation.
https://www.rt.com/news/381879-fukushima-reactor-radiation-lethal/
Survey under way of Fukushima Daiichi 1 vessel
The PMORPH robot within unit 1’s PCV
A robot has entered into the primary containment vessel of the damaged unit 1 of the Fukushima Daiichi plant and provided Tokyo Electric Power Company (Tepco) with radiation and temperature measurements within it. The company hopes the data, together with video footage, will enable it to locate the molten fuel in the unit.
On 18 March, Tepco inserted the PMORPH robot into unit 1 in the first of a series of four planned robot explorations of the basement area of its primary containment vessel (PCV) around the pedestal, on which the reactor pressure vessel sits. The investigation is part of preparatory work for the eventual removal of fuel debris.
The PMORPH robot was developed by Hitachi-GE Nuclear Energy and the International Research Institute for Nuclear Decommissioning (IRID). It can assume a long, straight shape for passing through narrow spaces, such as pipes. Alternatively, it can rotate its crawlers by 90 degrees in relation to its central body to assume a U-shape, with the crawlers providing better stability when travelling over flat surfaces.
The robot features a combined total of five cameras and also includes a winch used for lowering and raising a sensor unit that incorporates an underwater radiation-resistant camera, LED and a dosimeter.
In the latest investigation, the robot travelled along a section of the first floor grating, on which it measured a radiation dose of 7.8 Sieverts per hour. The robot also lowered its sensor unit into the water that has collected at the bottom of the primary containment vessel. At a height of about 1 metre above the PCV basement floor, Tepco recorded a dose level of 1.5 Sv/h. The robot also recorded temperature measurements within the PCV of 14-23°C.
Last month a “scorpion-shaped” robot developed by Toshiba and IRID was sent into the primary containment vessel of unit 2 of the Fukushima Daiichi plant. “In that case,” Tepco said, “although the robot was obstructed from reaching all the way into the pedestal area, important information was obtained about the conditions at the base of the reactor.” Readings indicate the temperature within the area of the containment vessel where the robot stopped was around 16.5°C and the dose rate was about 210 Sv/h, significantly higher than those measured in unit 1.
Tepco said the latest reading and images obtained from unit 1 will now be examined in greater detail. “The conditions of the PCV basement floor will be examined later,” it noted.
The insertion of the PMORPH robot follows an investigation of the unit’s containment vessel by another shape-changing robot in April 2015. That was the first time a robot had entered the containment vessel of any of the damaged units. However, after taking several images and measurements, that robot got stuck in the grating and stopped working.
Tepco is preparing to conduct similar investigations using a robot in unit 3 at the plant.
http://www.world-nuclear-news.org/RS-Survey-under-way-of-unit-1-vessel-2003174.html
1 This Month
of the week – Shut Down Drone Warfare!
Tell the Ukrainian Government to Drop Prosecution of Peace Activist Yurii Sheliazhenko
Petition to revoke the licensing of the Near Surface Nuclear Disposal Facility (NSDF) at Chalk River. https://www.ourcommons.ca/petitions/en/Petition/Details?Petition=e-7247
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