A new investigative robot, equipped with a censoring unit hanging through metal grating, is scheduled to be send into the No. 1 reactor at the Fukushima No. 1 nuclear power plant in the coming months. (Kohei Tomida)
HITACHI, Ibaraki Prefecture–Another robot has been developed for the elusive goal of locating melted fuel and surveying the interior of the No. 1 reactor at the Fukushima No. 1 nuclear plant.
A team of engineers and researchers from Hitachi-GE Nuclear Energy Ltd. and the International Research Institute for Nuclear Decommissioning revealed the robot on Feb. 3.
Tokyo Electric Power Co., operator of the plant, plans to deploy the robot into the No. 1 reactor before the end of March.
The robot will be fitted with a censoring unit mounted with a camera, dosimeter and lighting. Its purpose is to give TEPCO an idea of the location and condition of the melted nuclear fuel in the reactor.
Most of the melted fuel is believed to have fallen through the reactor’s pressure vessel, landed on the bottom of the surrounding containment vessel, and is soaking in cooling water about 2 meters deep.
The new robot will maneuver around metal grating originally set up for maintenance work about 3.5 meters above the bottom of the containment vessel.
At each of five survey points, the robot will lower the censoring unit through the grating. The unit can operate in water.
In April 2015, TEPCO sent two robots into the No. 1 reactor, but they could not locate the melted fuel.
One of them became stuck, and high radiation levels disabled the camera on the other. TEPCO abandoned the machines in the reactor.
On Jan. 30, a remote controlled video camera sent into the No. 2 reactor took what are believed to be the first images of melted fuel at the plant.
In Mali Martha Lightfoot’s own words: ” The measuring capacity is just getting better and they are reaching parts of the containment they were unable to monitor before. I think it’s important not to confuse more accurate readings with the misconception that they indicate that the levels are rising. It is shocking enough to get an indication of how high the levels still are. And we may find, as technology improves, that parts of the containment are higher still. But, that still does not indicate that the levels are rising, just that our ability to design monitoring devices is getting better. “
As Majia Nadesan is saying in her own blog article : “A separate article published in The Asahi Shimbun notes that radiation levels in units 1 and 3 remain so high (higher than unit 2) that TEPCO is unable to investigate conditions in there: If confirmed, the first images of melted nuclear fuel at the Fukushima No. 1 nuclear plant show that Tokyo Electric Power Co. will have a much more difficult time decommissioning the battered facility. The condition of what is believed to be melted fuel inside the No. 2 reactor at the plant appears far worse than previously thought. …High radiation levels have prevented workers from entering the No. 2 reactor, as well as the No. 1 and No. 3 reactors at the plant. MASANOBU HIGASHIYAMA (January 31, 2017) Images indicate bigger challenge for TEPCO at Fukushima plant. The Asahi Shimbun, http://www.asahi.com/ajw/articles/AJ201701310073.html
If radiation levels are at 530 sieverts an hour inside unit 2, I wonder what conditions are like in the 1 and 3 reactors, which are described as even hotter? I can tell you from watching the reactors on the webcams for 5 plus years that atmospheric emissions from unit 3 have never ceased (as illustrated below far right side of screenshot)”. http://majiasblog.blogspot.fr/2017/02/fukushima-daiichi-unit-2-measures-530.html
Anyway in the meantime those 3 reactors are still belly button opened up spitting high radiation into our skies and environment, the reactor 1 and 3 even higher radiation than reactor 2.
TEPCO is reporting measuring radiation levels of 530 SIEVERTS AN HOUR (10 will kill you dead pretty quickly) and has discovered a 2-meter hole in the grating beneath the reactor pressure vessel (1 meter-square hole found in grating):
TOKYO (Kyodo) — The radiation level inside the containment vessel of the No. 2 reactor at the crippled Fukushima Daiichi nuclear complex stood at 530 sieverts per hour at a maximum, the highest since the 2011 disaster, the plant operator said Thursday.
Tokyo Electric Power Company Holdings Inc. also announced that based on image analysis, a hole measuring 2 meters in diameter has been found on a metal grating beneath the pressure vessel inside the containment vessel and a portion of the grating was distorted.
…The hole could have been caused by nuclear fuel that penetrated the reactor vessel as it overheated and melted due to the loss of reactor cooling functions in the days after a powerful earthquake and tsunami on March 11, 2011 hit northeastern Japan.
According to the image analysis, about 1 square meter of the grating was missing.
…Images captured using a camera attached to a telescopic arm on Monday also showed part of the grating has gone. A further analysis of the images found a 2-meter hole in an area beyond the missing section on the structure.
A separate article published in The Asahi Shimbun notes that radiation levels in units 1 and 3 remain so high (higher than unit 2) that TEPCO is unable to investigate conditions in there:
If confirmed, the first images of melted nuclear fuel at the Fukushima No. 1 nuclear plant show that Tokyo Electric Power Co. will have a much more difficult time decommissioning the battered facility.
The condition of what is believed to be melted fuel inside the No. 2 reactor at the plant appears far worse than previously thought.
…High radiation levels have prevented workers from entering the No. 2 reactor, as well as the No. 1 and No. 3 reactors at the plant.
If radiation levels are at 530 sieverts an hour inside unit 2, I wonder what conditions are like in the 1 and 3 reactors, which are described as even hotter?
I can tell you from watching the reactors on the webcams for 5 plus years that atmospheric emissions from unit 3 have never ceased (as illustrated below far right side of screenshot):
There is some dispute about the recent high level of radiation measured inside the Fukushima Daiichi reactor 2, thanks to the Japan Times unprecise english translation of the Kyodo News Japanese language article.
They have been able to measure these highest radiation levels only now because they couldn’t get as close to where they think the melted fuel may be with monitors before. Not the highest levels ever present at the site. That would have been around the time of the accident, or soon after. The radiation levels at the site do not appear to be rising, they are just now able to get deeper inside the reactor containment before the monitors fail, and so they get better readings.
The Japan Times article’s title is ok: “Highest radiation reading since 3/11 detected at Fukushima No. 1 reactor”. Yes, it is the highest radiation reading found since 3/11 because since 3/11 Tepco had not been able to reach such deep place to measure the radiation there. So this recent reading is the highest found since 3/11.
The Japan Times article in itself does not mention directly any radiation increase or “spike. But their wording “has reached” in “The radiation level in the containment vessel of reactor 2 at the crippled Fukushima No. 1 power plant has reached a maximum of 530 sieverts per hour, the highest since the triple core meltdown in March 2011, Tokyo Electric Power Co. Holdings Inc. said” could be misconstrued as meaning that the high level recently found is resulting from an increase of radiation, when compared to the lower level previously found . Which is not the case. Their previous reading was lower because they had not been able to go that deep before to monitor radiation there.
The Japan Times article then misled some western media, such as the Guardian, Popular Mechanic and others to themselves publish misconstrued articles based on the Japan Times article as their source.
The Popular Mechanics article’s title was ok: “Highest Radiation Levels Since Meltdown Recorded at Fukushima” but their subtitle is entirely wrong and misleading: “Levels haven’t been this high since the actual meltdown in 2011.” That subtitle is wrong, the levels were maybe that high or even higher, but Tepco had not been able to reach there before to find out, to take such measure in that place, at that deep level. That subtitle is wrong, suggesting that there is an increase. Popular Mechanics misconstrued the article of Japan Times and drawed the wrong conclusion. http://www.popularmechanics.com/technology/infrastructure/a25034/radiation-spikes-fukushima-possible-breach/
The Guardian ‘s article title is in itself misleading: ” Fukushima nuclear reactor radiation at highest level since 2011 meltdown”. A title such as “Fukushima nuclear reactor radiation highest level to date found since 2011 meltdown” would have been better and more accurate. The added words “to date found” would clarify that it was maybe already there before but that it had not been found yet, because they had not been able to reach that place and that deep before to take such measure. In its text it fails to mention the real reason why the measure recently found is higher than the previous measure. This all results in the Guardian article saying that this highest recent measure compared to the lower previous one is due to an increase of radiation. This is absolutely wrong, a complete misconstruction of the real facts. https://www.theguardian.com/environment/2017/feb/03/fukushima-daiichi-radiation-levels-highest-since-2011-meltdown?CMP=share_btn_fb
And many other western media and websites went along and repeated the same blind misconstruction.
Thanks heavens there were two websites who noticed the error made by those mainstream media and many other websites. They stepped in trying to correct that misconstruction and to re-establish the true facts. The Simply Info Fukuleaks website and the Safecast website, thanks to both websites’ bloggers team for their vigilance and their efforts in keeping the facts straight.
We can’t say that there has been an increase in radiation because we do not know that. To know that we would need to have a previous measure at the same deep at the same place to compare both measures. But such previous measure that deep at that place we do not have, so it is impossible to draw any conclusion at this stage, only that it is very high.
Now what we really need is a second probe at the same deep at the same place, to confirm the first probe readings, but also to compare the recent readings and the next readings so as to assess if the radiation levels there are stable or not, if there will be an increase of radiation between the two probes or not…Until such second probing takes place, at this stage no one can say anything about any occuring increase…
Fukushima radiation levels at highest level since 2011 meltdown
Cranes over the Fukushima Daiichi plant in February 2016. The decommissioning process is expected to take about four decades
Extraordinary readings pile pressure on operator Tepco in its efforts to decommission nuclear power station
Radiation levels inside a damaged reactor at the Fukushima Daiichi nuclear power station are at their highest since the plant suffered a triple meltdown almost six years ago.
The facility’s operator, Tokyo Electric Power (Tepco), said atmospheric readings as high as 530 sieverts an hour had been recorded inside the containment vessel of reactor No 2, one of three reactors that experienced a meltdown when the plant was crippled by a huge tsunami that struck the north-east coast of Japan in March 2011.
The extraordinary radiation readings highlight the scale of the task confronting thousands of workers, as pressure builds on Tepco to begin decommissioning the plant – a process that is expected to take about four decades.
The recent reading, described by some experts as “unimaginable”, is far higher than the previous record of 73 sieverts an hour in that part of the reactor.
A single dose of one sievert is enough to cause radiation sickness and nausea; 5 sieverts would kill half those exposed to it within a month, and a single dose of 10 sieverts would prove fatal within weeks.
Tepco also said image analysis had revealed a hole in metal grating beneath the same reactor’s pressure vessel. The one-metre-wide hole was probably created by nuclear fuel that melted and then penetrated the vessel after the tsunami knocked out Fukushima Daiichi’s back-up cooling system.
“It may have been caused by nuclear fuel that would have melted and made a hole in the vessel, but it is only a hypothesis at this stage,” Tepco’s spokesman Tatsuhiro Yamagishi told AFP.
“We believe the captured images offer very useful information, but we still need to investigate given that it is very difficult to assume the actual condition inside.”
The presence of dangerously high radiation will complicate efforts to safely dismantle the plant.
A remote-controlled robot that Tepco intends to send into the No 2 reactor’s containment vessel is designed to withstand exposure to a total of 1,000 sieverts, meaning it would survive for less than two hours before malfunctioning.
The firm said radiation was not leaking outside the reactor, adding that the robot would still prove useful since it would move from one spot to the other and encounter radiation of varying levels.
Tepco and its network of partner companies at Fukushima Daiichi have yet to identify the location and condition of melted fuel in the three most seriously damaged reactors. Removing it safely represents a challenge unprecedented in the history of nuclear power.
Quantities of melted fuel are believed to have accumulated at the bottom of the damaged reactors’ containment vessels, but dangerously high radiation has prevented engineers from accurately gauging the state of the fuel deposits.
Earlier this week, the utility released images of dark lumps found beneath reactor No 2 that it believes could be melted uranium fuel rods – the first such discovery since the disaster.
In December, the government said the estimated cost of decommissioning the plant and decontaminating the surrounding area, as well as paying compensation and storing radioactive waste, had risen to 21.5tn yen (£150bn), nearly double an estimate released in 2013.
Radiation level in Fukushima reactor could kill within a minute
Images show black lumps on grating for maintenance work below the No. 2 reactor’s pressure vessel at the Fukushima No. 1 nuclear power plant. TEPCO says melted fuel likely caused at least two holes in the metal grating, including an opening measuring 1 meter by 1 meter. (Provided by Tokyo Electric Power Co.)
Radiation levels that can kill a person in a minute and holes created by melted nuclear fuel could further delay decommissioning operations at the No. 2 reactor of the Fukushima No. 1 nuclear plant.
Tokyo Electric Power Co., operator of the crippled plant, said Feb. 2 that the maximum estimated radiation level near what is believed to be melted fuel in the reactor was 530 sieverts per hour, the highest so far since the triple meltdown in 2011.
In its investigation into the interior of the No. 2 reactor, TEPCO also confirmed at least two holes on grating for maintenance work below the bottom of the reactor’s pressure vessel.
The images show the area at the bottom of the No. 2 reactor’s pressure vessel to the metal grating below.
“The holes were likely made when the melted nuclear fuel fell from the pressure vessel and melted the grating,” a TEPCO official said.
The findings were made by studying images taken from a video camera attached to a pipe that was inserted into the reactor on Jan. 30.
Radiation levels were estimated at 20 sieverts per hour, 50 sieverts per hour and 530 sieverts per hour at three spots inside the reactor’s containment vessel.
The company estimated the doses from the extent of disturbances in the images caused by radiation.
Although a TEPCO official said “there is a margin of error because radiation levels were not measured directly,” the company believes the scattered melted nuclear fuel inside the containment vessel was emitting high levels of radiation.
After a number of failed attempts, the remote-controlled camera took the first pictures of possible melted fuel at the plant.
However, closer inspection of the images have revealed additional problems for TEPCO, which had believed most of the melted fuel had remained inside the reactor’s pressure vessel.
TEPCO plans to send an investigative robot, called Sasori (scorpion), into the containment vessel this month to more accurately measure radiation doses at various spots and take additional footage of the scattered nuclear fuel.
The utility plans to use the data to determine a fuel-removal method.
But the robot was expected to use the circular grating, measuring 5 meters in diameter, to move around. One of the holes is 1 meter by 1 meter, a potential pitfall for the robot, which is 59 centimeters long and 9 cm high.
TEPCO said it will consider a different route for the robot in its survey.
Fumiya Tanabe, an expert on nuclear safety who analyzed the 1979 Three Mile Island nuclear accident in the United States, said the findings show that both the preparation for and the actual decommissioning process at the plant will likely prove much more difficult than expected.
“We have few clues on the exact locations, the sizes and the shapes of the nuclear fuel debris,” he said. “The planned investigation by the robot needs a rethink. Work to decommission the plant will require even more time.”
TEPCO said it will need 30 to 40 years to complete the decommissioning process. The utility plans to start work to remove the melted nuclear fuel at the No. 2 and two other stricken reactors in 2021 after deciding on a removal method in fiscal 2018.
TEPCO has yet to determine the location and the condition of the melted fuel in the other two reactors.
An executive of the operator of the crippled Fukushima Daiichi nuclear complex said Friday the company plans to probe inside the plant’s No. 2 reactor by the end of February to confirm whether the black mass spotted in a recent survey was nuclear debris.
Naohiro Masuda, the chief decommissioning officer at Tokyo Electric Power Company Holdings Inc. told Kyodo News it is “possible” to conduct the probe using a robot, the day after the operator announced it had detected extraordinarily high radiation levels inside the reactor.
The operator will be able to tell whether the deposits are nuclear debris from the March 2011 meltdown if new images and data such as the radiation levels and temperatures are obtained in the upcoming robot survey, he said.
Radiation inside the containment vessel of the No. 2 reactor at the Fukushima No. 1 nuclear plant measures as high as a deadly 530 sieverts per hour, the highest since the 2011 disaster, plant operator Tokyo Electric Power Co. (TEPCO) announced on Feb. 2.
TEPCO calculated the radiation dose from video noise on footage it took inside the containment vessel in late January, when a camera was inserted to examine conditions inside and scout a route for a scorpion-like observation robot scheduled to go into the vessel later this month.
Deployment of the robot is also being reconsidered after two gaping holes were found along the robot’s planned path over a 5-meter-wide circular walkway inside the containment vessel, close to where the 530-sievert radiation dose was detected.
A scorpion-like observation robot scheduled to go into the containment vessel of the No. 2 reactor at the Fukushima No. 1 nuclear plant.
The holes in the metal grate walkway — one of unknown size and the other measuring about 1 meter square — make both routes considered for the robot impassable.
“We will consider re-evaluating what observations we can take with the robot,” Yuichi Okamura, an acting general manager with TEPCO’s on-site nuclear power division, told reporters at a Feb. 2 news conference.
Piles of a black and dark brown substance several centimeters thick and thought to be melted nuclear fuel were also observed on the walkway, creating a further possible obstruction to the robot. Meanwhile, examination of the 1-meter-square hole suggests the walkway was struck with tremendous force, hinting that there may be a large amount of melted fuel below.
“It is possible that the nuclear fuel rods melted onto the control rods and then dripped down,” Tokyo Institute of Technology professor of nuclear engineering Yoshinao Kobayashi told the Mainichi Shimbun. “It’s highly likely that part of the bottom of the pressure vessel broke and the melted fuel flowed down (onto the walkway), and then the grating warped and gave way due to the fuel’s heat.”
The plaintiff helped build scaffolding to repair the damaged No 4 reactor at the Fukushima plant
A Japanese court has begun hearing the case of a man who developed leukaemia after working as a welder at the damaged Fukushima nuclear site.
The plaintiff, 42, is the first person to be recognised by labour authorities as having an illness linked to clean-up work at the plant.
He is suing Tokyo Electric Power Company, which operates the complex.
The nuclear site was hit by the earthquake and tsunami in 2011, causing a triple meltdown.
It was the world’s worst nuclear disaster since Chernobyl in 1986. An exclusion zone remains in place around the site as thousands of workers continue clean-up efforts.
‘Expendable labourer’
The man, from Japan’s Fukuoka prefecture, was a welder for a sub-contractor.
He spent six months working at Genkai and Fukushima No 2 nuclear plants before moving to the quake-hit Fukushima No 1 plant, where he build scaffolding for repair work at the No 4 reactor building. His cumulative radiation exposure was 19.78 millisieverts.
This is lower than official limits – Japan currently allows workers at the damaged plant to accumulate a maximum of 100 millisieverts over five years. A dose of 100 millisieverts over a year is seen as enough to raise the risk of cancer.
But in October 2015, a health ministry panel ruled that the man’s illness was workplace-related and that he was eligible for compensation.
“While the causal link between his exposure to radiation and his illness is unclear, we certified him from the standpoint of worker compensation,” a health ministry official said at the time.
There has been heated debate about the dangers of radiation from the plant
The man is now suing Tepco and the Kyushu Electric Power Company, which operated the Genkai plant, for JPY59m ($526,000, £417,000).
“I worked there [Fukushima No 1 plant] because of my ardent desire to help bring the disaster under control but I was treated as if I was a mere expendable labourer,” Kyodo news agency quoted him as saying.
“I want Tokyo Electric to thoroughly face up to its responsibility.”
When he filed the suit late last year, his lawyers said he had been “forced to undergo unnecessary radiation exposure because of the utilities’ slipshod on-site radiation management”.
Tepco and Kyushu Electric have asked the court to reject the suit, questioning the link between his radiation exposure and leukaemia, Kyodo reported.
Tens of thousands of workers have been employed at the Fukushima site since the disaster in March 2011. Late last year the government said estimates of clean-up costs had doubled to JPY21.5 trillion ($188bn, £150bn).
Ex-worker during Fukushima disaster sues Tepco, Kyushu Electric over leukemia
A former nuclear worker who developed leukemia after combating the 2011 Fukushima nuclear crisis demanded ¥59 million (around $524,000) in damages from two utilities Thursday at his first trial hearing at the Tokyo District Court.
The 42-year-old man from Fukuoka Prefecture is the first person to be recognized by labor authorities as having an illness linked to workplace radiation exposure since the triple core meltdown at the Fukushima No. 1 nuclear power plant.
The man-made disaster was triggered by the huge earthquake and tsunami on March 11, 2011.
“I worked there because of my ardent desire to help bring the disaster under control but I was treated as if I was a mere expendable laborer,” the plaintiff said.
“I want Tokyo Electric to thoroughly face up to its responsibility,” he said.
The defendants, Tokyo Electric Power Company Holdings Inc., which runs Fukushima No. 1, and Kyushu Electric Power Co., whose Genkai nuclear plant also employed the plaintiff, asked the court to reject the claim, questioning the connection between his radiation exposure and leukemia.
The man was engaged in welding operations at the Fukushima Nos. 1 and 2 plants and the Genkai complex in Saga Prefecture from October 2011 to December 2013. His exposure in operations subcontracted by the utilities consisted of at least 19.8 millisieverts, according to his written complaint.
The man was diagnosed with acute myeloid leukemia in January 2014 and later went into depression. Both ailments are recognized as work-related illnesses by the Health, Labor and Welfare Ministry.
He said he has been unable to go back to work and is therefore seeking compensation from the utilities.
The operator of the crippled Fukushima Daiichi nuclear plant says its latest estimation of the radiation level inside one of the reactors was extremely high and had the potential to be lethal to a human within a short period of time.
Tokyo Electric Power Company conducted an inspection inside the containment vessel of the plant’s No.2 reactor last month using a remote-controlled camera, as part of a survey to scrap the reactor.
An analysis of the images found that the radiation was up to 530 sieverts per hour at a concrete cylinder supporting the reactor.
The level is enough to be lethal to a human within a short period of time, despite a possible error margin of up to 30 percent.
A survey conducted 1 year after the nuclear accident at a different part inside the same containment vessel logged 73 sieverts per hour.
In the latest estimation inside the vessel, the area near its opening logged 50 sieverts per hour at maximum.
The operator officials say that there are no leaks of gas with radioactive substances from the containment vessel.
Officials suspect that fuel debris; a mixture of nuclear fuel and melted parts of the reactor’s facility, may be emitting strong radiation inside the vessel.
Some molten fuel penetrated the reactor’s bottom and has reached the containment vessel as fuel debris.
The company plans conduct further inspections with a robot. There is a risk that some parts of the grating where the robot will be moving may be damaged by the high heat of the molten fuel.
Record high fatal radiation levels, hole in reactor detected at crippled Fukushima nuclear facility
Record high radiation levels that’s lethal even after brief exposure have been detected at a damaged reactor at the Fukushima power plant in Japan. Specialists also found a hole, likely caused by melted nuclear fuel.
Radiation levels of up to 530 Sieverts per hour were detected inside an inactive Reactor 2 at the Fukushima Daiichi nuclear complex damaged during the 2011 earthquake and tsunami catastrophe, Japanese media reported on Thursday citing the plant operator, Tokyo Electric Power Company (TEPCO).
A dose of about 8 Sieverts is considered incurable and fatal.
A hole of no less than one square meter in size has also been discovered beneath the reactor’s pressure vessel, TEPCO said. According to researchers, the apparent opening in the metal grating of one of three reactors that had melted down in 2011, is believed to be have been caused by melted nuclear fuel that fell through the vessel.
The iron scaffolding has a melting point of 1500 degrees, TEPCO said, explaining that there is a possibility the fuel debris has fallen onto it and burnt the hole. Such fuel debris have been discovered on equipment at the bottom of the pressure vessel just above the hole, it added.
The latest findings were released after a recent camera probe inside the reactor, TEPCO said. Using a remote-controlled camera fitted on a long pipe, scientists managed to get images of hard-to-reach places where residual nuclear material remained. The substance there is so toxic that even specially-made robots designed to probe the underwater depths beneath the power plant have previously crumbled and shut down.
However, TEPCO still plans to launch further more detailed assessments at the damaged nuclear facility with the help of self-propelled robots.
Earlier this week, hopes for a more efficient cleanup at Fukushima were high, as the plant operator announced a portion of nuclear fuel debris responsible for a lot of the lingering contamination from six years ago may have finally been found.
TOKYO (Kyodo) — The radiation level inside the containment vessel of the No. 2 reactor at the crippled Fukushima Daiichi nuclear complex stood at 530 sieverts per hour at a maximum, the highest since the 2011 disaster, the plant operator said Thursday.
Tokyo Electric Power Company Holdings Inc. also announced that based on image analysis, a hole measuring 2 meters in diameter has been found on a metal grating beneath the pressure vessel inside the containment vessel and a portion of the grating was distorted.
According to TEPCO, the extremely high radiation level was found near the entrance area in the space just below the pressure vessel. The previously highest radiation level monitored in the interior of the reactor was 73 sieverts per hour.
The hole could have been caused by nuclear fuel that penetrated the reactor vessel as it overheated and melted due to the loss of reactor cooling functions in the days after a powerful earthquake and tsunami on March 11, 2011 hit northeastern Japan.
According to the image analysis, about 1 square meter of the grating was missing.
The plant operator plans to deploy a robot at the bottom of the reactor containment vessel, which houses the reactor pressure vessel, to check the conditions there.
The analysis follows TEPCO’s discovery Monday of a black mass deposited on the grating directly beneath the pressure vessel, possibly melted fuel after the unit suffered a meltdown along with two other Fukushima Daiichi reactors.
Images captured using a camera attached to a telescopic arm on Monday also showed part of the grating has gone. A further analysis of the images found a 2-meter hole in an area beyond the missing section on the structure.
If the deposits are confirmed as fuel debris, it would be the first time the utility has found any at the three units that suffered meltdowns.
Following one of the world’s worst nuclear disasters since the 1986 Chernobyl catastrophe, the No. 1 to 3 reactors suffered fuel meltdowns.
Portions of the fuel in the reactors are believed to have melted through the pressure vessels and accumulated at the bottom of the containment vessels.
The actual condition of the melted fuel has remained unknown due to high radiation levels.
A video taken on Jan. 30 shows the bottom of the No. 2 reactor’s pressure vessel at the Fukushima No. 1 nuclear power plant. Water used to cool the nuclear fuel is dripping, and possible melted fuel is seen strewn on grating for maintenance work. (Provided by Tokyo Electric Power Co.)
If confirmed, the first images of melted nuclear fuel at the Fukushima No. 1 nuclear plant show that Tokyo Electric Power Co. will have a much more difficult time decommissioning the battered facility.
The condition of what is believed to be melted fuel inside the No. 2 reactor at the plant appears far worse than previously thought.
Before the pictures were taken by a remote-controlled video camera on Jan. 30, TEPCO presumed that most of the nuclear fuel at the No. 2 reactor had remained within the reactor’s pressure vessel. That presumption was based on findings of a study conducted last year involving cosmic rays.
As a result, TEPCO did not expect the camera to detect possible nuclear fuel debris below the pressure vessel.
But the images showed black lumps scattered on a wire-mesh grating in the lower part of the containment vessel, which encloses the pressure vessel. This indicates that the fuel melted through bottom of the pressure vessel, spilled through the grating and fell on the floor of the containment vessel.
This image of the area below the No. 2 reactor’s pressure vessel at the Fukushima No. 1 nuclear power plant was taken on Jan. 30. Experts believe nuclear fuel melted the paint and components of equipment nearby and has hardened. (Provided by Tokyo Electric Power Co.)
The grating, which was used by maintenance workers before the disaster, was partially bent.
The images could show only part of the melted fuel in the No. 2 reactor. And there is still no indication on how widespread the black lumps were strewn, their volume and state.
TEPCO and government authorities in fiscal 2018 plan to decide on a method to retrieve the melted fuel from each of the three crippled reactors and start the removal work in 2021.
But a number questions remain unanswered, such as how to reduce workers’ radiation exposure, where the removed fuel will be kept, and when it will be disposed of.
The pictures raise another question: How will workers cut out the wire-mesh grating embedded with lumps of melted fuel?
The images were the first of possible nuclear fuel debris at the nuclear plant since the Great East Japan Earthquake and tsunami caused the triple meltdown there in March 2011.
Sasori (Scorpion), an investigative robot, is expected to be sent in the containment vessel of the No. 2 reactor of the Fukushima No. 1 nuclear power plant in February.
High radiation levels have prevented workers from entering the No. 2 reactor, as well as the No. 1 and No. 3 reactors at the plant.
A number of problems have hampered investigations by robots into the location of melted fuel at the No. 1 and No. 3 reactors.
From December 20, 2013, but this video made by Arnie Gundersen and his Fairwinds team gives us useful info for decades to come.
I completely agree with my friend Kitty, I could not have said it better that in her own words:
“I remember when Arnie started publishing and appearing on TV about Fukushima. Arnie Gundersen quickly won me over with his objective and detailed description of the situation. We would be very in the dark if it were not for Arnie Gundersen, Maggie Gundersen and others.
Many nuclear power plants are shutting down because of their and others, primary reporting of the ongoing Fukushima Catastrophe. Many nuclear projects discontinued. More time on earth for us and our children. Maybe some help and solace to nuclear victims and refugees everywhere.
What Arnie said in the video about why Fukushima is so hard to cleanup, is because of the groundwater. there must be enough of the groundwater and debris out of reactor two, to get a good picture now. Tepco should be doing everything it can to keep groundwater put. this includes building a dike and wall as Arnie says.”
Thank you Arnie Gundersen, thank you Maggie Gundersen, thank you Fairwinds for all the good work you did over the past years and still are doing, very much appreciated by many people in many countries.
In this, the fourth installment in their short film series, from December 2013, Fairewinds Energy Education’s Arnie Gundersen responds to questions they have received about cleanup at Fukushima Daiichi. Please consider supporting their work, so they can continue to bring us the truth about nuclear power.
The footage released on Jan. 30 by Tokyo Electric Power Co. (TEPCO) showing what could be melted fuel inside the No. 2 reactor at the disaster-stricken Fukushima No. 1 Nuclear Power Plant has highlighted the difficulty of salvaging the object, which is apparently stuck to footholds and other equipment at the facility.
TEPCO took the footage as part of its in-house probe into the No. 2 reactor and found that black and brown sediments — possible melted fuel — are stuck inside the reactor’s containment vessel over an extensive area.
“If what was captured in the footage was melted fuel, that would provide a major step forward toward trying our hand at unprecedented decommissioning work,” said Yoshiyuki Ishizaki, head of TEPCO’s Fukushima Revitalization Headquarters, during a press conference in the city of Fukushima on Jan. 30. “The finding may provide a major clue to future work to retrieve the object,” he added.
At the time of the March 2011 meltdowns at the plant, there were 548 nuclear fuel rods totaling some 164 metric tons inside the No. 2 reactor, but they apparently melted down after the loss of power sources for the core cooling system, with part of the melted fuel penetrating through the pressure vessel before cooling down at the bottom of the containment vessel. The temperature of the reactor core topped 2,000 degrees Celsius at the time of the accident, melting metals including nuclear fuel inside the reactor.
The melted fuel has since come in contact with underground water flowing from the mountain side, generating radioactively contaminated water every day. In order to dismantle the reactor, it is necessary to take out the melted fuel, but high radiation levels inside the reactor had hampered work to locate the melted debris.
On Jan. 30, apart from the footage, TEPCO also released 11 pictures taken inside the No. 2 reactor. The images show the sediments in question stuck to metal grate footholds and water is dripping from the ceiling. Further analysis of those images may provide information on the current status of the disaster and positional clues to decommissioning work.
The in-house probe, however, has only focused on the No. 2 reactor, and there is no prospect of similar probes into the No. 1 and No. 3 reactors starting anytime soon as they were severely damaged by hydrogen explosions following the 2011 meltdowns.
In April 2015, TEPCO introduced a remote-controlled robot into the No. 1 reactor by way of a through hole in its containment vessel, but the device failed to locate melted fuel inside due to high radiation levels. While the utility is planning to send a different type of robot into the No. 1 reactor this coming spring, it would be difficult to carry out a survey similar to that conducted at the No. 2 reactor, as radiation levels are high around the through hole in the No. 1 reactor’s containment vessel, from which a device could access to right below the No. 1 reactor.
The No. 3 reactor, meanwhile, holds roughly 6.5-meter-deep contaminated water inside its containment vessel, a far larger volume than that accumulated at the No. 1 and No. 2 reactors. TEPCO has thus been developing a robot that can wade through water.
Material found below the damaged No 2 reactor at Fukushima nuclear plant, believed to be melted fuel, from footage taken on 30 January.
Operator says it has seen what may be fuel debris beneath badly damaged No 2 reactor, destroyed six years ago in triple meltdown
Hopes have been raised for a breakthrough in the decommissioning of the wrecked Fukushima Daiichi nuclear plant after its operator said it may have discovered melted fuel beneath a reactor, almost six years after the plant suffered a triple meltdown.
Tokyo Electric Power (Tepco) said on Monday that a remote camera appeared to have found the debris beneath the badly damaged No 2 reactor, where radiation levels remain dangerously high. Locating the fuel is the first step towards removing it.
The operator said more analysis would be needed before it could confirm that the images were of melted uranium fuel rods, but confirmed that the lumps were not there before Fukushima Daiichi was hit by a powerful earthquake and tsunami on 11 March 2011.
The tsunami, triggered by a 9.0-magnitude quake, killed more than 18,500 people along the coast of north-east Japan and destroyed the backup power supply at Fukushima Daiichi, triggering the world’s worst nuclear accident since Chernobyl 25 years earlier.
If Tepco can confirm that the black mass comprises melted fuel, it would represent a significant breakthrough in a recovery effort that has been hit by mishaps, the buildup of huge quantities of contaminated water, and soaring costs.
“This is a big step forward as we have got some precious data for the decommissioning process, including removing the fuel debris,” a Tepco official said.
Using a remotely controlled camera attached to the end of a 10.5-metre-long telescopic arm, Tepco technicians located black lumps on wire-mesh grating just below the reactor’s pressure vessel, local media reported.
The company plans to send a scorpion-like robot equipped with cameras, radiation measuring equipment and a temperature gauge into the No 2 reactor containment vessel next month, according to the Asahi Shimbun.
Three previous attempts to use robots to locate melted fuel inside the same reactor ended in failure when the devices were rendered useless by radiation.
Developing the means to remove the fuel – a task Tepco has said will become easier once it can gauge its condition – would be the biggest step forward in the mission to clean up Fukushima Daiichi since the removal of hundreds of spent fuel rods from a damaged reactor building in late 2013.
The delicate, potentially dangerous task of decommissioning the plant has barely begun, however.
Japanese media said last week that plans to remove spent fuel from the No 3 reactor building had been delayed, while decommissioning the entire plant was expected to take at least 40 years.
In December, the government said the estimated cost of decommissioning the plant and decontaminating the surrounding area, as well as paying compensation and storing radioactive waste, had risen to 21.5 trillion yen ($187bn), nearly double an estimate released in 2013.
A government committee estimated that 2.4 trillion yen of the total cost would be passed on to consumers through higher electricity bills.
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