Cleaner robot pulled from Fukushima reactor due to radiation — Beloit Daily News

” TOKYO (AP) — A remote-controlled cleaning robot sent into a damaged reactor at Japan’s Fukushima nuclear plant had to be removed Thursday before it completed its work because of camera problems most likely caused by high radiation levels.

It was the first time a robot has entered the chamber inside the Unit 2 reactor since a March 2011 earthquake and tsunami critically damaged the Fukushima Da-ichi nuclear plant.

Tokyo Electric Power Co. said it was trying to inspect and clean a passage before another robot does a fuller examination to assess damage to the structure and its fuel. The second robot, known as the “scorpion,” will also measure radiation and temperatures.

Thursday’s problem underscores the challenges in decommissioning the wrecked nuclear plant. Inadequate cleaning, high radiation and structural damage could limit subsequent probes, and may require more radiation-resistant cameras and other equipment, TEPCO spokesman Takahiro Kimoto said.

“We will further study (Thursday’s) outcome before deciding on the deployment of the scorpion,” he said.

TEPCO needs to know the melted fuel’s exact location and condition and other structural damage in each of the three wrecked reactors to figure out the best and safest ways to remove the fuel. It is part of the decommissioning work, which is expected to take decades.

During Thursday’s cleaning mission, the robot went only part way into a space under the core that TEPCO wants to inspect closely. It crawled down the passage while peeling debris with a scraper and using water spray to blow some debris away. The dark brown deposits grew thicker and harder to remove as the robot went further.

After about two hours, the two cameras on the robot suddenly developed a lot of noise and their images quickly darkened — a sign of a problem caused by high radiation. Operators of the robot pulled it out of the chamber before completely losing control of it.

The outcome means the second robot will encounter more obstacles and have less time than expected for examination on its mission, currently planned for later this month, though Thursday’s results may cause a delay.

Both of the robots are designed to withstand up to 1,000 Sieverts of radiation. The cleaner’s two-hour endurance roughly matches an estimated radiation of 650 Sieverts per hour based on noise analysis of the images transmitted by the robot-mounted cameras. That’s less than one-tenth of the radiation levels inside a running reactor, but still would kill a person almost instantly.

Kimoto said the noise-based radiation analysis of the Unit 2’s condition showed a spike in radioactivity along a connecting bridge used to slide control rods in and out, a sign of a nearby source of high radioactivity, while levels were much lower in areas underneath the core, the opposite of what would normally be the case. He said the results are puzzling and require further analysis.

TEPCO officials said that despite the dangerously high figures, radiation is not leaking outside of the reactor.

Images recently captured from inside the chamber showed damage and structures coated with molten material, possibly mixed with melted nuclear fuel, and part of a disc platform hanging below the core that had been melted through. ”

by Mari Yamaguchi

source with photos

Fukushima frozen wall status 2017; Unit 3 cover building installation — SimplyInfo.org

SimlyInfo.org shows a map of the current status of the frozen ice wall at Fukushima No. 1.

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Read SimplyInfo.org’s article on the current construction of a cover building for Fukushima Daiichi’s Unit 3, which will hopefully allow for robotic removal of spent fuel.

 

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

source

Underwater robots to assist with Fukushima cleanup — Engineering and Technology Magazine

” Radiation-sensing amphibious robots will help speed up decommissioning of the damaged Fukushima nuclear power plant.

Currently under development by an international research team, the technology will finally provide means for assessing radiation in the submerged parts of the reactor.

“Our research will focus on developing a remote-operated submersible vehicle with detection instruments that will be able to identify the radioactive sources,” said Malcolm Joyce, Professor of Nuclear Engineering at Lancaster University, who leads the team.

“This capability does not currently exist and it would enable clean-up of the stricken Fukushima reactors to continue.”

Focusing particularly on dangerous neutron and gamma radiation, the robots will be able to assess how stable the situation is in the submerged parts of the nuclear power plant. For safe decommissioning, debris as well as fuel needs to be removed from the reactor, but the high risk is that some accidental reaction could be triggered by the manipulation.

“A key challenge with the remote-operated vehicle will be to design it so that it can fit through the small access ports typically available in nuclear facilities,” explained Barry Lennox, Professor of Applied Control at the University of Manchester. “These ports can be less than 100 mm in diameter, which will create significant challenges.”

Scientists from universities in Lancaster and Manchester are working on the project, which is funded by the Engineering and Physical Sciences Research Council, together with partners from Japan and private company Hybrid Instruments.

The remotely controlled vehicle that will come out of the project could also be used in decommissioning of undamaged nuclear sites, such as the Sellafield Reprocessing facility in Cumbria, or it could serve the oil and gas industry in assessing natural deposits of radioactive materials.

The reactors of the Fukushima Daiichi nuclear power plant, damaged during the 9.0-magnitude earthquake in 2011, had to be flooded with sea water to cool them down.

“A key task is the removal of the nuclear fuel from the reactors,” Joyce said. “Once this is removed and stored safely elsewhere, radiation levels fall significantly making the plant much more safer, and cheaper, to decommission.” ”

source

Fuel rod casings found damaged by debris — NHK World

” Workers at the crippled Fukushima Daiichi nuclear plant have been preparing to remove hundreds of fuel rod assemblies from a pool of the facility’s No. 3 reactor building.

The workers have found damaged fuel rod containers after removing a device that had fallen on them during the 2011 disaster. They’re now checking whether the damage will affect their plan to remove fuel from the pool.

A 20-ton device for moving fuel rods in and out of the pool on the building’s top floor was removed on Sunday, more than 4 years after the nuclear accident. High radioactivity prevented workers from carrying out the removal smoothly.

The plant’s operator, Tokyo Electric Power Company, checked the condition of 566 fuel rod assemblies in the pool.

Workers found that the metal casings of 4 assemblies had been distorted and have twisted handles. This is evident in images released by the operator. It says the fuel rods appear undamaged, as radiation levels in the pool have shown no irregularities.

The utility is checking for other damage and studying how to remove the distorted casings from the pool.

Removing fuel rod assemblies from spent fuel pools is an important part of decommissioning work at the plant. More than 1,500 assemblies are still in pools at 3 of the facility’s reactor buildings. ”

source

Fukushima compensation increased to ¥7 trillion — The Japan Times

” The government has approved an increase in compensation payments for the Fukushima nuclear crisis to ¥7.07 trillion as tens of thousands of evacuees remain in temporary housing more than four years after the disaster.

Tokyo Electric Power Co will receive ¥950 billion more in public funds on top of the ¥6.125 trillion agreed earlier, the utility and the government said Tuesday.

The increase, agreed after a request by Tepco, adds to the bill for taxpayers for the disaster.

Tepco has face a stream of legal cases seeking compensation over the disaster at its Fukushima No. 1 nuclear plant.

Electricity bills for households have also risen 25 percent since the catastrophe as the country resorted to importing more fossils fuels with the gradual shutdown of all reactors for safety checks and upgrades.

Prime Minister Shinzo Abe’s government and Tepco, which was bailed out by taxpayers in 2012, are undertaking an unprecedented cleanup to lower radiation levels in towns closest to the plant, although some areas will likely remain off-limits for decades.

Inside the plant, Tepco has struggled to bring the situation under control and it is estimated removing the melted fuel from the wrecked reactors and cleaning up the site will cost trillions of yen and take decades to complete.

The government plans to revoke evacuation orders for most people forced from their homes by the disaster within two years as part of a plan to cap compensation payouts and speed up reconstruction. ”

source