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

Advertisements

Tepco mandated to create fund for scrapping Fukushima plant — The Japan Times

” The Diet passed a bill Wednesday requiring Tokyo Electric Power Company Holdings Inc. to put aside extra funds to decommission its crisis-hit Fukushima nuclear power plant, as the state seeks to gain more financial control over the utility.

Under the revised law, the state-backed Nuclear Damage Compensation and Decommissioning Facilitation Corp. will also be involved in the decommissioning process.

Currently, Tepco has been using profits to pay for scrapping the Fukushima No. 1 plant, which was destroyed after a 2011 earthquake and tsunami triggered a triple meltdown.

The revised law is expected to take effect later this year. With the estimated cost of the decommissioning work already surging to ¥8 trillion from the previously forecast ¥2 trillion, a government panel has called for setting up a funding system that is not dependent on the company’s financial health.

The government projects the total cost to deal with the Fukushima nuclear disaster will reach ¥21.5 trillion, including decommissioning costs, compensation and decontamination work.

Under the new program, the state-backed organization will decide on the amount Tepco should store away each business year and the industry minister must approve it.

The utility must also formulate a financial plan and obtain the minister’s approval when it uses the reserve fund for its decommissioning work.

The new law will strengthen the monitoring power of authorities as well, enabling the industry ministry and the organization to conduct on-site inspections to check whether Tepco is putting aside the money.

The government has a major say in the utility’s operations after acquiring 50.1 percent of the company’s voting rights. Tepco faces huge compensation payments and decommissioning costs among other problems due to the 2011 disaster.

The industry ministry has projected roughly ¥300 billion will be needed annually for the next 30 years to complete the scrapping of the power plant, which involves the difficult procedure of extracting nuclear debris.

The costs could grow further. A study by a Tokyo-based private think tank has shown the bill for the decommissioning could balloon to between ¥11 trillion and ¥32 trillion assuming materials from the No. 1 to 3 reactors, which suffered core meltdowns, need to be specially treated for radioactive waste.

The Japan Center for Economic Research estimated the total cost of managing the disaster could reach ¥70 trillion, more than three times the government calculation. ”

by Kyodo, The Japan Times

source

Plans to remove nuclear fuel at Fukushima delayed again — Reuters via Channel NewsAsia

” A plan to remove spent nuclear fuel from Tokyo Electric Power Co Holdings Inc’s Fukushima Daiichi nuclear plant hit by the March 2011 tsunami has been postponed again due to delays in preparation, the Nikkei business daily reported on Thursday.

Work is now set to begin in fiscal 2018 at the earliest, the Nikkei said.

Removal of the spent fuel from the No. 3 reactor was originally scheduled in the first half of fiscal 2015, and later revised to fiscal 2017 due to high levels of radioactivity around the facilities, the Japanese business daily reported.

The timeline has been changed again as it was taking longer than expected to decontaminate buildings and clean up debris, the news agency reported.

The report comes a few months after the Japanese government said in October the cost of cleaning up the Fukushima plant may rise to several billion dollars a year, adding that it would look into a possible separation of the nuclear business from the utility. ”

Reporting by Krishna V Kurup in Bengaluru, editing by Shounak Dasgupta, REUTERS

source

Last cover removed from crippled reactor in Fukushima — The Asahi Shimbun; Crippled Fukushima reactor fully exposed for first time since meltdown — RT

The Asahi Shimbun:

” The No. 1 reactor at the Fukushima No. 1 nuclear power plant is completely exposed for the first time in five years after the last of the temporary protective covers for the crippled structure was removed Nov. 10.

The next step will be to extract nuclear fuel inside the reactor building, which was wrecked by a hydrogen explosion in the early stages of the March 2011 nuclear disaster.

The covers were installed the following October as a temporary measure against the spread of radioactive substances after the triple meltdown triggered by the Great East Japan Earthquake and tsunami.

A large crane lifted off the 20-ton cover, the last of the 18 panels installed, around 6 a.m. on Nov. 10.

Plant operator Tokyo Electric Power Co. began removing the covers one by one in September.

The 392 fuel assemblies are stored in the spent nuclear fuel pool inside the building. Melted fuel also remains inside the reactor.

TEPCO will assess the state of the reactor building’s interior in efforts to remove debris from the collapse of a roof over the spent nuclear fuel pool.

It will take precautions to prevent dust containing radioactive substances from being stirred up by shrouding the reactor building with tarpaulins. ”

by Kohei Tomida

source with aerial view video of uncovered Unit 1 reactor

* * *

RT:

” Fukushima’s Nuclear Plant reactor No. 1 has been fully exposed for the first time since the March 2011 tragedy, after the utility company safely removed the last cover sheet of the temporary protective construction.

Tokyo Electric Power Co. (TEPCO) used an industrial crane to lift the last of its 18 protective panels Thursday. Each of the panels weighs around 20 tons and measure 23 by 17 meters.

The protective cover was erected in October 2011 as a temporary measure to halt a radiation leak following a meltdown caused by a powerful earthquake and tsunami in March 2011. The dismantling of the panels started in July 2015 and was concluded on Thursday.

At Unit 1, rubble from the damaged building caused by the hydrogen explosion remains scattered and needs to be removed. The entire site is highly contaminated and will now be covered with tarpaulins to avoid the spread of radioactive waste. TEPCO is using anti-scattering agents to keep the dust down. Small pieces of rubble that can create dust are being vacuumed up while mist sprinklers are being used inside the building to keep radiation under control.

TEPCO next plans to remove 392 fuel assemblies from the spent pool and clean out the melted nuclear fuel from inside the building, NHK news reported. The utility company is assessing the level of radiation before continuing the cleanup process.

Scientists are also installing the necessary equipment to complete fuel extraction which will only start in four years. Fuel removal from Unit 1’s depleted fuel pool is scheduled to begin around March 2021, according to TEPCO’s Mid- and Long-Term Roadmap that was revised in June 2015.

In March 2011, a tsunami destroyed emergency generators at the plant. They had been cooling the reactors. The tsunami led to three nuclear meltdowns and the release of radioactive material. In Reactor 1, overheating caused the creation of hydrogen gas. On March 12, an explosion in Unit 1 destroyed the upper part of the building.

TEPCO’s decommission plan for the Fukushima nuclear power plant implies at least a 30-40 year period before the consequences of the meltdown are fully eliminated. So far the clean-up efforts have already cost Japan in excess of $21 billion. According to the latest estimates from the Ministry of Economy, Trade and Industry, the decommissioning costs will top $105 billion. ”

source

Fukushima cleanup talks put Tepco survival risk in focus — Bloomberg

” Tokyo Electric Power Co. is still struggling to put the Fukushima nuclear disaster behind it, admitting this week that paying for decommissioning the plant in one go risks leaving it insolvent.

The cost to insure debt in Japan’s biggest utility climbed to a seven-month high of 89 basis points on Oct. 5 after President Naomi Hirose said after a meeting in Tokyo with a government commission that the company is asking for help in avoiding financial ruin. Tepco has already received state aid for compensation and decontamination.

The March 2011 nuclear accident and its fallout will ultimately cost more than 11 trillion yen ($106 billion), according to a study by academics including Kenichi Oshima, a professor of economics at Ritsumeikan University. Tepco has estimated that decommissioning alone will cost about 2 trillion yen. Investors should hold off buying bonds of other utilities until there is more clarity on how the government will close the Fukushima plant, according to BNP Paribas SA.

“Now is not the best time to be investing in electricity utility bonds, with discussions going on about nuclear plant decommissioning, and the potential for spreads to widen,” said Mana Nakazora, chief credit analyst at BNP Paribas in Tokyo. Even so, she added, “the government has little choice but to take measures to avoid a default by Tokyo Electric.”

While Prime Minister Shinzo Abe’s government has committed to provide up to 9 trillion yen for compensation to individuals and business hurt by the Fukushima disaster and for decontaminating areas affected, that figure doesn’t include decommissioning of the nuclear plant itself, according to a report by Moody’s Investors Service last month.

Scrapping the Fukushima reactors may take 30 years to 40 years, and Tokyo Electric will only start removing debris from the plant from in 2021, a decade after the incident, according to the utility’s road map for dealing with the remnants of the disaster.

In speaking to reporters, Tepco President Hirose was probably making a public case for more government support, according to Yutaka Ban, the chief credit analyst at SMBC Nikko Securities Inc. in Tokyo. Ban said he saw little probability that support will be withheld.

“Things will likely settle down” after the government adopts the new measures, said Ban. “Without government support, the costs would be extremely high.” …

Tepco’s credit-default swaps have come down from as high as 1,762 basis points in October 2011, according to data provider CMA. The utility has said it plans to return to the bond market by the end of the fiscal year to March 2017. Jun Oshima, a spokesman for Tokyo Electric, said that plan is still in place. It stopped issuing notes after the Fukushima disaster.

The extra yield on Tepco’s 1.155 percent bonds due in 2020 was 64 basis points more than sovereign debt, the lowest since before the Fukushima disaster, according to Bloomberg-compiled prices. The spread on Osaka-based Kansai Electric Power Co.’s 0.976 percent notes due in 2020 was 39 basis points.

Tokyo Electric has a Ba3 rating from Moody’s and BB- score from S&P Global Ratings, both three levels below investment grade.

“Decommissioning is currently the biggest unknown, and clarity matters in terms of credit,” said Mariko Semetko, a Moody’s analyst in Tokyo. “The lack of clarity there has been holding back the credit quality.” ”

by Finbarr Flynn, Tesun Oh, and Emi Urabe

source

Test run for Fukushima Daiichi 3 cover installation — World Nuclear News

” In preparation for the installation of a fuel removal machine and a protective cover over unit 3 of the damaged Fukushima Daiichi plant in Japan, workers have carried out a practice run of installing roof modules onto the base of the fuel handling machine.

Plans were announced in November 2012 for a cover to be constructed to encase the unit’s damaged reactor building, protecting it from the weather and preventing any release of radioactive particles during decommissioning work.

The section of the reactor building that sheltered the service floor of unit 3 was wrecked by a hydrogen explosion three days after the tsunami of March 2011 – leaving the fuel pond exposed and covered by debris including many twisted steel beams.

The fabrication of the cover has been under way since November 2013 at the Onahama works in Iwaki city. It has been made in sections so that once it is transported to Fukushima Daiichi, the time to assemble it can be shortened and the radiation exposure to the workers on site can be significantly reduced, Tokyo Electric Power Company (Tepco) said.

A separate structure will be built to facilitate the removal by crane of used fuel from the storage pool. This 54-metre-tall structure will include a steel frame, filtered ventilation and an arched section at its top to accommodate the crane. Measuring 57 metres long and 19 metres wide, it will not be fixed to the reactor building itself, but will be supported on the ground on one side, and against the turbine building on the other.

A detailed replica of a portion of the Fukushima Daiichi site has been created at Onahama to enable workers to train in highly realistic conditions, Tepco said. Training began in May and will continue through June.

On 10 June, workers at Onahama assembled sections of the cover on the base of the specially-made fuel removal machine and slid them into place to make a roof, Tepco announced.

Although the largest pieces of rubble have already been removed, once installed the remotely-operated fuel removal machine will be used to clear the remaining rubble and the 566 fuel assemblies from the unit’s storage pool. The removal of debris and fuel using the system is scheduled to begin in fiscal 2017.

The fuel removed from unit 3 will be packaged for transport the short distance to the site’s communal fuel storage pool, although it will need to be inspected and flushed clean of dust and debris. ”

source