Japanese robot probes the radioactive water at Fukushima’s nuclear reactor to find melted fuel — Daily Mail

” A Japanese robot has begun probing the radioactive water at Fukushima’s nuclear reactor.

The marine robot, nicknamed the ‘little sunfish’, is on a mission to study structural damage and find fuel inside the three reactors of the devastated plant.

Experts said remote-controlled bots are key to finding fuel at the dangerous site, which has likely melted and been submerged by highly radioactive water.

The probe – about the size of a loaf of bread – is equipped with lights, manoeuvres using tail propellers and collects data using two cameras and a dosimeter radiation detector.

Plant operators chose to send the robot inside the containment vessel of the No. 3 reactor because it has highest known water levels out of the the three reactors.

The robot entered the structure at 6.30am JST (10.30 BST, 5.30 ET) through a pipe connected to the containment vessel.

The marine machine, which was attached to cables, then swam to the area just below the reactor pressure vessel inside to take images.

New images taken by the robot show how parts of the system, including the control rod, have been damaged by radiation.

On Friday, the robot will continue its travels to the bottom of the containment vessels, where melted fuel deposits are believed to have accumulated.

In 2011, a 10-metre-high tsunami that killed nearly 19,000 people crashed into Japan’s Fukushima nuclear power plant, leading to several meltdowns.

Five years after the disaster, researchers are still struggling to clean up the highly dangerous radioactive materials in water of the wasting reactors.

It’s estimated that plant officials have only located 10 per cent of the waste fuel left behind after the nuclear meltdowns.

And the damaged plant is believed to be leaking small amounts of the radioactive waste into the Pacific Ocean, which could be travelling as far as the west cost of the US.

Researchers are now pinning their hopes on the remote-controlled sunfish robot to locate the lost fuel in order to work out the safest way to remove it.

During a demonstration of the device at a test facility near Tokyo last month, the probe slowly slid down from a rail and moved across the water.

A team operated it remotely, with one guiding the robot while another adjusted a cable that transmits data and serves as its lifeline.

Japan hopes to locate and start removing fuel from the reactors after Tokyo’s 2020 Olympics.

In earlier operations, snake and scorpion-shaped robots became stuck inside two reactors.

The scorpion robot’s crawling function failed and it was left inside the plant’s Unit 2 containment vessel.

The other, designed for cleaning debris for the ‘scorpion’ probe, was called back after two hours when two of its cameras stopped working after its total radiation exposure reached 1,000 Sievert – a level that would kill a human within seconds.

The plan had been to use the robot for 10 hours at an exposure level of 100 Sievert per hour.

The swimming robot shown was co-developed by electronics and energy giant Toshiba and the government’s International Research Institute for Nuclear Decommissioning. “

by Daisy Dunne, Mail Online and Associated Press

source with photos and video

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Fukushima’s ¥8 trillion cleanup leaves foreign firms in the cold — The Japan Times

” Cleaning up the Fukushima nuclear plant — a task predicted to cost 86 times the amount earmarked for decommissioning Japan’s first commercial reactor — is the mother of all salvage jobs. Still, foreign firms with decades of experience are seeing little of the spoils.

Safely dismantling the Japanese power plant, wrecked by the 2011 earthquake and tsunami, will cost about ¥8 trillion ($70 billion), the Ministry of Economy, Trade and Industry said on Dec. 9, quadrupling the previous estimate. While a contract to help clean up the facility would be a windfall for any firm with specialized technology, the lion’s share of the work has gone to local companies that designed and built most of Japan’s atomic infrastructure.

The bidding process for Fukushima contracts should be more open to foreigners, as Japan has never finished decommissioning a commercial nuclear plant, let alone one that experienced a triple meltdown, according to Lake Barrett, an independent adviser at Japan’s International Research Institute for Nuclear Decommissioning. While the Fukushima cleanup is unlike any nuclear disaster in history, foreign firms that have experience decommissioning regular facilities could provide much-needed support, according to Barrett, and even the plant’s operator, Tokyo Electric Power Co. Holdings Inc.

‘Cultural Resistance’

“Internationally, there is a lot more decontamination and decommissioning knowledge than you have in Japan,” Barrett, a former official at the U.S. Nuclear Regulatory Commission, said in an interview in Tokyo. “I hope the Japanese contracting system improves to get this job done safely. There is this cultural resistance — it is almost like there is an isolated nuclear village still.”

An opaque bidding process plays to the heart of criticisms put forward by independent investigators, who said in a 2012 report that collusion between the government, regulators and the plant’s operator contributed to the scale of the disaster.

Of 44 subsidized projects publicly awarded by the trade and economy ministry since 2014, about 80 percent went to the International Research Institute for Nuclear Decommissioning. The group, known as IRID, was established in the wake of the Fukushima disaster and is comprised entirely of Japanese corporations, according to the ministry’s website.

Japan’s trade and industry ministry awarded funds directly to only two foreign firms during the same period. Many of the contracts had only one or two bidders.

Of about 70 contracts awarded since the March 2011 disaster, nine have gone to foreign companies, according to an official in the ministry’s Agency of Natural Resources and Energy who asked not be named, citing internal policy.

To provide opportunities for foreign companies, the ministry has created an English website for bids and also provides English information sessions to explain the contracts, the official said.

Toshiba, Hitachi

IRID’s contracts are given to its members, including Toshiba Corp., Hitachi Ltd. and Mitsubishi Heavy Industries Ltd., which have partnerships and joint ventures with foreign firms, spokesman Yoshio Haruyama said by phone. While it doesn’t directly contract work to companies overseas, IRID taps foreign experts as advisers and participates in international collaborative projects, he said.

Mitsubishi Heavy has about five or six contracts through IRID, but can’t share how many partnerships it has with foreign firms, spokesman Shimon Ikeya said by phone. Hitachi has sub-contracts with foreign suppliers related to the Fukushima cleanup, but can’t provide details about these agreements because they aren’t public, a spokesperson said by email.

As of March, IRID had about ¥30 billion worth of ongoing contracts primarily related to research and development of fuel removal and waste treatment. IRID, which aims to “gather knowledge and ideas from around the world” for the purpose of nuclear decommissioning, doesn’t disclose how much of their money ultimately goes to foreign businesses, according to its spokesman. Barrett, its adviser, said he thinks it’s “very low,” but should ideally be 5 percent to 10 percent.

‘Nuclear Village’

Japan’s biggest nuclear disaster isn’t void of foreign technology. Toshiba, which owns Pennsylvania-based Westinghouse Electric Co., and Hitachi, which has a joint venture with General Electric Co., are tapping American expertise. A giant crane and pulley system supplied by Toshiba to remove spent fuel from the wrecked reactors employs technology developed by Westinghouse.

“We bring in knowledge from foreign companies, organizations and specialists in order to safely decommission the reactors,” Tatsuhiro Yamagishi, spokesman for Tepco, said by email. While the company can’t say the exact number of foreign firms involved in the Fukushima cleanup, companies including Paris-based Areva SA, California-based Kurion Inc. and Massachusetts-based Endeavor Robotics are engaged in work at the site, according to Yamagishi.

For foreign firms, however, independently securing contracts is still a tall order.

“When it comes to Japan’s nuclear industry, the bidding system is completely unclear,” Hiroaki Koide, a former assistant professor at Kyoto University Research Reactor Institute, said in an email. “The system is designed to strengthen the profits of Japan’s nuclear village,” he added, referring to the alliance of pro-nuclear politicians, bureaucrats and power companies that promote reactors.

Tepco’s annual cost to decommission its Fukushima plant may blow out to several hundred billion yen a year, up from the current estimate of ¥80 billion, the trade and industry ministry said in October. As of June, almost ¥1 trillion has been allocated for decommissioning and treating water at Fukushima, according to Tepco’s Yamagishi.

‘Ripe for Corruption’

With that much money at stake, Japan has become ground zero for a plethora of companies looking to benefit from the cleanup work. The structure of Japan’s nuclear industry and the closed procurement preferred by the utilities that operate atomic plants means that the most lucrative opportunities for foreign companies are in the area of subcontracting, according to a report by the EU-Japan Centre for Industrial Cooperation released in March.

“Foreign firms have long argued that the Japanese bidding process is one that is ripe for corruption due to a lack of openness and transparency,” Daniel Aldrich, professor and director of the security and resilience studies program at Northeastern University in Boston, said in an email. For nuclear decommissioning “there is even less clarity and transparency due to security and proliferation concerns,” he said.

Rigging Bids

The Japan Fair Trade Commission raided the offices of five companies last year in relation to rigged bids for maintenance contracts from Tepco, according to Jiji Press. Eleven road-paving companies were fined in September on projects to repair roads following the March 2011 earthquake and tsunami, Jiji reported.

Andrew DeWit, a political economy professor at Rikkyo University in Tokyo, agrees that the contract-awarding process isn’t transparent. A lot of foreign companies seek Japanese partners to better their chances, he said.

Purolite Corp., a closely held water purifying company, spent millions of dollars developing and testing a system that could be used to treat radioactive water at Fukushima. Pennsylvania-based Purolite partnered with Hitachi to help win a contract to use its technology at the wrecked facility.

Those plans didn’t pan out. Purolite is suing Hitachi in New York and Tokyo, alleging that Hitachi is using its technology at Fukushima in breach of agreements made in 2011, shutting it out of more than $1 billion in contracts, according to court documents filed in September.

Hitachi doesn’t comment on ongoing legal matters, a spokesperson said by email.

“With a smaller pool of competitors, firms can expand their profit margins,” said Northeastern University’s Aldrich. “There are French and Russian firms that have the technical expertise to participate in nuclear decommissioning processes, but it is unclear if they will be able to compete on a level playing field with Japanese firms, which have far more experience with Japanese regulations and expectations.” ”

by Stephen Stapczynski, Bloomberg

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Five years after the meltdown, is it safe to live near Fukushima? — Science

” A  long, grinding struggle back to normal is underway at the Fukushima Daiichi Nuclear Power Plant in Japan. As workers make progress in cleaning up contaminated land surrounding its infamous reactor, evacuees are grappling with whether to return to homes sealed off since the accident there 5 years ago. The power plant itself remains a dangerous disaster zone, with workers just beginning the complex, risky job of locating the melted fuel and figuring out how to remove it.

The magnitude 9.0 earthquake that struck northeastern Japan on 11 March 2011 and the 40-meter tsunami that followed left 15,893 dead and 2572 missing, destroyed 127,290 buildings, and damaged more than a million more. It also triggered the meltdowns at Fukushima and the evacuation of 150,000 people from within 20 kilometers of the nuclear plant as well as from areas beyond that were hard hit by fallout.

Now, the nuclear refugees face a dilemma: How much radiation in their former homes is safe? In a herculean effort, authorities have so far scooped up some 9 million cubic meters of contaminated soil and leaves and washed down buildings and roadways with the goal of reducing outdoor radiation exposure to 0.23 microsieverts per hour. Last September, the government began lifting evacuation orders for the seven municipalities wholly or partly within 20 kilometers of the plant. As the work progresses, authorities expect that 70% of the evacuees will be allowed to return home by spring 2017.

But evacuees are torn over safety and compensation issues. Many claim they are being compelled to go home, even though radiation exposure levels, they feel, are still too high. “There has been no education regarding radiation,” says Katsunobu Sakurai, the mayor of Minamisoma, where 14,000 people were evacuated after the accident. “It’s difficult for many people to make the decision to return without knowing what these radiation levels mean and what is safe,” he says. Some citizen groups are suing the national government and Tokyo Electric Power Company (TEPCO), the Fukushima plant’s owner, over plans to end compensation payments for those who choose not to return home. Highly contaminated areas close to the nuclear plant will remain off limits indefinitely.

Conditions at the plant are “really stable,” the plant manager, Akira Ono, recently told reporters. Radioactivity and heat from the nuclear fuel have fallen substantially in the past 5 years, he says. But cleanup is off to a slow start, hampered by sketchy knowledge of where the nuclear fuel is located. Last year managers agreed to a road map for decommissioning the site over the next 30 to 40 years that calls for removing melted nuclear fuel masses and demolishing the plant’s four reactor halls at a cost that could top $9 billion. TEPCO intends to start removing nuclear debris from the reactors in 2021.

Ono puts the decommissioning at “around 10%” complete. One big hurdle was cleared in December 2014, when crews removed the last of 1535 fuel rods stored in the Unit 4 spent fuel pool. At the time of the accident, some feared that cooling water had drained out of the pool and exposed the fuel to air, which might have led to overheating and melting. It hadn’t, but the fuel remained a threat.

The biggest challenge at present, Ono says, is contaminated water. Cooling water is continuously poured over the melted cores of units 1, 2, and 3 to keep the fuel from overheating and melting again. The water drains into building basements, where it mixes with groundwater. To reduce the amount of contaminated water seeping into the ocean, TEPCO collects and stores it in 10-meter-tall steel tanks. They now fill nearly every corner of the grounds, holding some 750,000 tons of water. The government is evaluating experimental techniques for cleansing the water of a key radioisotope, tritium. Ono says a solution is sorely needed before the plant runs out of room for more tanks.

TEPCO has found ways to divert groundwater from the site, cutting infiltration to about 150 tons per day. Now it’s about to freeze out the rest. Borrowing a technique for making temporary subsurface barriers during tunnel construction, a contractor has driven 1500 pipes 30 meters down to bedrock, creating something akin to an underground picket fence encircling the four crippled reactor units. Brine chilled to –30°C circulating in the pipes will freeze the soil between the pipes; the frozen wall should keep groundwater out and contaminated water in. TEPCO was planning to start the operation shortly after Science went to press.

The most daunting task is recovering the fuel debris. TEPCO modeling and analyses suggest that most, if not all, of the fuel in the Unit 1 reactor melted, burned through the reactor pressure vessel, dropped to the bottom of the containment vessel, and perhaps ate into the concrete base. Units 2 and 3 suffered partial meltdowns, and some fuel may remain in the cores.

To try to confirm the location and condition of the melted fuel, the International Research Institute for Nuclear Decommissioning, set up by TEPCO and other entities, has been probing the reactors’ innards with muons. Wispy cousins of the electron, muons are generated by the trillions each minute when cosmic rays slam into the upper atmosphere. A few muons are absorbed or scattered, at a rate that depends on a material’s density. Because uranium is denser than steel or concrete, muon imaging can potentially locate the fuel debris.

In February 2015, a group at Japan’s High Energy Accelerator Research Organization in Tsukuba supplied two van-sized muon detectors, which TEPCO placed adjacent to the Unit 1 reactor at ground level. After a month of collecting muons, the detectors confirmed there was no fuel left in the core. Because they were positioned at ground level, the devices could not image the reactor building basements and so could not pin down where the fuel is or its condition. TEPCO plans to use robots to map the location of the fuel debris so it can develop a strategy for removing it (see story, right).

A second team has developed detectors that observe muons before and after they pass through an object of interest, promising a more precise picture of reactor interiors. For Fukushima, the researchers—from Los Alamos National Laboratory in New Mexico and Japan’s Toshiba Corp.—built mammoth detectors, 7 meters across, which they intended to place outside Unit 2. That work has been postponed because TEPCO decided to first send a robot into the containment vessel; high radiation levels have delayed that plan. “Our current task is to reduce that exposure,” Ono says, using robotic floor and wall scrubbers in the area workers need to access to deploy the robot.

While the authorities struggle to clean up the site and resettle residents, some locals are judging safety for themselves. In 2014, a group of enterprising high school students in Fukushima city, outside the evacuation zone, launched an international radiation-dosimetry project. Some 216 students and teachers at six schools in Fukushima Prefecture, six elsewhere in Japan, four in France, eight in Poland, and two in Belarus wore dosimeters for 2 weeks while keeping detailed diaries of their whereabouts and activities. “I wanted to know how high my exposure dose was and I wanted to compare that dose with people living in other places,” explains Haruka Onodera, a member of Fukushima High School’s Super Science Club, which conceived the project. The students published their findings last November in the Journal of Radiological Protection. Their conclusion: “High school students in Fukushima [Prefecture] do not suffer from significantly higher levels of radiation” than those living elsewhere, Onodera says.

That’s good news for Fukushima city residents, perhaps, but cold comfort to displaced people now weighing the prospect of moving back to homes closer to the shattered nuclear plant. ”

by Dennis Normile

source

New robot to map Fukushima reactors — BBC News

” A new robot designed to help decommission reactors at the Fukushima nuclear plant is to undergo tests before entering the harsh radioactive environment, it’s been reported.

Developed by the Universities of Tokyo and Tsukuba, and the International Research Institute for Nuclear Decommissioning (IRID), the remotely-controlled robot will use 360-degree cameras and lasers to create a three-dimensional map of the inside of the reactor buildings. It will help plant operator Tepco to know how much wreckage needs to be cleared before decontamination work can begin, Japanese newspaper The Mainichi reports.

The cameras, which are mounted on top of the robot, will give a panoramic view to scientists who have so far been hampered by a lack of clear information. “We’ve expanded the field of vision, so it should give the workers operating the robot a bird’s-eye view of what they’re doing,” an unnamed project official tells The Mainichi.

The Fukushima plant suffered a meltdown after a massive earthquake and subsequent tsunami in March 2011. Efforts to clean up the site have been repeatedly held up by obstacles blocking remotely-controlled devices, as well as high levels of radiation inside the power plant. In April, a robot failed after three hours inside the reactor building, and while a flying drone has been tested for use at the site, it has not entered the most badly damaged buildings. It’s estimated that decontaminating the Fukushima site will take up to 40 years and cost tens of billions of dollars. ”

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Updated 4/13/15: Survey robot breaks down inside Fukushima No. 1 reactor in under three hours — The Japan Times

Updated April 13, 2015, The Japan Times: ” A remote-controlled robot inserted to survey the inside of the No. 1 reactor at the damaged Fukushima No. 1 nuclear power plant has stopped functioning, Tokyo Electric Power Co. said.

As a first step in the utility’s effort to remove melted nuclear fuel from the bottom of the unit’s primary containment vessel, the shape-shifting robot was sent in Friday morning to find the exact location of the highly radioactive debris.

Set to cover some 20 meters of the first floor on the first day, the robot began its trip at around 11:20 a.m. but halted at around 2:10 p.m. after completing two-thirds of the route, Tepco said.

The utility said footage from the robot’s camera shows it passed an opening leading to the vessel’s basement, where the molten fuel is believed to have ended up after the core meltdowns occurred after the March 2011 quake and tsunami. ”

source

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Posted April 10, 2015, The Japan Times, “Robot enters primary containment vessel of reactor 1 in Fukushima”:

” A robot on Friday crept into the deadly primary containment vessel of reactor 1 of the Fukushima No. 1 power plant to surveil its damaged interior, Tokyo Electric Power Co. said.

It is the first time a robot has entered the PCV of any of the three stricken reactors at the meltdown-hit plant, and the snake-like contraption might give the utility a better idea of what happened to the pressure vessel and its core in the disaster.

Tepco plans to have the robot check half of the first floor of the bulbous PCV on Friday and examine the other half on Monday.

Ultimately, the utility plans to explore the underground portion of the vessel, where the melted fuel rods are believed to have puddled. But that is not yet feasible because the robot isn’t waterproof. A waterproof version is expected to be developed by the end of next March.

The snake-like robot, about 9.5 cm high and 60 cm long, entered the vessel through a pipe 10 cm in diameter. After going down to the first floor, it was to assume a U shape and measure temperature and radiation levels. It was also to photograph the interior and check for obstacles in the area leading to the underground portion.

When a measuring device was snaked into the same vessel in October 2012, the radiation peaked at a deadly 11 sieverts per hour.

The fuel in reactor Nos. 1 to 3 is believed to have melted through their reactor pressure vessels and spread to the primary or other containment vessels. But the exact details are still a mystery more than four years after the crisis began because the site is too hostile to explore.

Developed by Hitachi-GE Nuclear Energy Ltd. and the International Research Institute for Nuclear Decommissioning, the robot is equipped with a camera, a thermometer and dosimeter.

Given the high radiation, it can only function for about 10 hours before the electronics fail, the institute said.

The robot will be remotely guided from a plant building where radiation is lower. About 40 workers will be involved and radiation exposure will be limited to 2.5 millisieverts or lower per person per day. ”

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Updated 2/9/15: Robotic snake set to examine innards of melted Fukushima reactor — The Japan Times; New ‘transformer’ robot changes shape to access deadly Fukushima nuclear facilities — The Asahi Shimbun

Updated Feb. 9, 2015, The Japan Times: ” A snakelike robot designed to examine the interior of one of the three meltdown-hit reactors at the Fukushima No. 1 nuclear power plant is ready to begin its expedition.

Assessing the damage in the reactors is a crucial step in decommissioning the poorly protected plant, which was crippled by core meltdowns triggered by the Great East Japan Earthquake and tsunami in March 2011.

Remote-controlled robots are essential for the job because the radiation in the reactors chambers is so high it would kill any person who got close.

Using information gathered by the robot, Tokyo Electric Power Co., the plant operator, plans to repair the damaged chambers enough so they can be filled with water in preparation to remove the melted radioactive debris, an operation planned to begin in about a decade.

The 60-cm-long robot, developed by electronics giant Hitachi and its nuclear affiliate Hitachi-GE Nuclear Energy, was demonstrated this week at a Hitachi-GE facility northeast of Tokyo. It is expected to enter the No. 1 reactor as early as April, officials said.

It has a lamp at the front and is designed to crawl like a snake through a 10-cm-wide pipe into the containment vessel. From there it must dangle and descend onto a platform just below the reactor core’s bottom, an area known as the pedestal.

There, the robot is to transform into a U-shaped crawler and capture live images and temperature and radiation levels and transmit them to a control station outside the building.

Expectations for the robot probe are high after earlier efforts at assessment met with limited success.

“Depending on how much data we can collect from this area, I believe (the probe) will give us a clearer vision for future decommissioning,” Hitachi-GE engineer Yoshitomo Takahashi said.

After its exploratory trip, which will make the robot extremely radioactive, technicians plan to store it in a shielded box. They have no plans to reuse it.

Different robots must be designed for each reactor, since each is slightly different.

According to computer simulations, all of the fuel rods in unit 1 probably melted and pooled at the bottom of the containment chamber, but there had been no way of confirming that until now.

A brief fiberscope observation conducted in 2012 produced images that were scratchy and of limited use.

To assess the debris at the bottom of the damaged reactor chambers, which are usually filled with water, an amphibious robot is being developed for deployment next year.

The damage from the melted fuel burned holes in the reactors, thwarting efforts to fill them with cooling water. As a result, water must be pumped into them continuously, producing an endless stream of radiation-contaminated water that is hampering the plant’s cleanup process. ”

source

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Posted Feb. 6, 2015, The Asahi Shimbun: ” HITACHI, Ibaraki Prefecture–A new shape-changing robot has been rolled out that can chart previously inaccessible areas of the damaged containment vessels at the crippled Fukushima No. 1 nuclear power plant.

The new device was demonstrated Feb. 5 at a plant owned by Hitachi-GE Nuclear Energy Ltd., one of the firms involved in its development. The International Research Institute for Nuclear Decommissioning, an organization made up of electric power companies and nuclear power plant manufacturers, developed it with a government subsidy.

The probe was conceived as a way to examine the containment vessels, which are too radioactive for humans to enter. It is scheduled for deployment at the No. 1 reactor building, which contains melted fuel, this spring.

The tubular-shaped robot, measuring 60 centimeters long in its normal state, can transform itself depending on the space it is trying to enter and the task to perform.

In the demonstration at the factory, the robot, in its tubular form, made its way through a pipe with a diameter of 10 cm. On the other side of the pipe, it changed shape to crawl around and capture images of the area.

The plan is to have the probe access the containment vessels through the holes in the wall through which electrical power lines pass.

Because strong radiation is harmful to electronic machines as well, the robot’s camera is only guaranteed to function for 10 hours. The device can also take radiation and temperature readings. ”

source with short clip of the new robot