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Total tally for Fukushima decommission is $75 billion

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April 2, 2018
The decommissioning of the Fukushima nuclear power plant will cost an annual $2 billion (220 billion yen) until 2021, an unnamed source told the Japan Times.
 
Half of the money will be used to tackle the radioactive water buildup at the site of the plant and for removing radioactive fuel from the fuel pools. A small amount of funds will be used to research ways of retreating melted fuel from the reactors that got damaged during the 2011 tsunami disaster.
 
The $6 billion for the three years is only part of the total estimated cost for taking Fukushima out of operation.
 
The total decommissioning tally came in at $75 billion (8 trillion yen), as estimated by the specially set up Nuclear Damage Compensation and Decommissioning Facilitation Corp (NDF). That’s four times more than the initial estimate of the costs around the NPP’s decommissioning.
 
Now the operator of Fukushima, Tepco, and the NDF are due to submit their financial plan for the facility to the government for approval by the energy industry minister.
 
In addition to the $6 billion allocated for the cleanup, Tepco will spend another $1.88 billion (200 billion yen) on preparing to start extracting the melted fuel from the three damaged reactors. This seems to be the biggest challenge for the cleanup efforts because of the still high radiation levels as well as technical difficulties.
 
Tepco is still reeling from the effects of the 2011 tsunami and resulting nuclear meltdown. Around 15,000 people died in March 2011, when a magnitude-9 quake caused a deadly tsunami and erased the coastline in the area of the nuclear power plant.
 
At the end of 2016, the Japanese government revised upwards the total costs of the disaster to $192 billion (21.5 trillion yen), stepping up pressure on Tepco to clean up its act and implement urgent reforms to its safety procedures.
 
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April 7, 2018 Posted by | Fukushima 2018 | , | 2 Comments

TEPCO’s priority is, and will be, to decommission crippled reactors

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March 14, 2018
Toyoshi Fuketa, chairman of the Nuclear Regulation Authority (NRA), told a news conference last week that the Fukushima nuclear accident is far from over, and that it would be a mistake to think of it solely as something that occurred seven years ago.
 
On the surface, it appears as if a semblance of order has been restored at the Fukushima No. 1 nuclear power plant, the site of one of the most catastrophic nuclear accidents in history. Except for in and around the crippled reactor buildings, workers can now go almost anywhere on the premises without protective clothing.
 
Measures have been set in place to cool debris from the reactor cores and spent nuclear fuel in storage pools.
 
The NRA has considerably downgraded the risk of the plant spewing massive amounts of radioactive substances again.
 
In reality, however, the road to reactor decommissioning is long and arduous.
 
“We are still in no state to see the peak of the mountain,” Fuketa said. “We don’t even know what sort of uphill slope awaits us.”
 
The government last year revised its timetable for reactor decommissioning. The basic target of “decommissioning in 30 to 40 years” has not changed, but the removal of spent fuel from the No. 1 and No. 2 reactor pools will not begin until fiscal 2023, three years later than initially projected.
 
With the state of the immediate surroundings of the reactor cores still being understood only vaguely, any decision on concrete steps for the removal of debris has been postponed by one year to fiscal 2019.
 
The volume of water containing radioactive substances, stored in 850 tanks, has reached 1 million tons, and it will only keep growing with the passage of time. The bloating costs of reactor decommissioning will translate into a heavier taxpayer burden. But trying to rush the job will raise the risk of exposing workers to radiation and inviting accidents.
 
Tokyo Electric Power Co. (TEPCO), the operator of the Fukushima No. 1 plant, started last summer to publicly announce troubles encountered by cleanup crews as “deviations from the norm.”
 
Such issues include injuries or acute illnesses suffered by workers, vehicular collisions while multiple operations are being simultaneously run, and the deterioration of machinery used in emergencies. While most of these cases do not constitute legal violations, they are being reported almost daily.
 
Ensuring the safety of workers is TEPCO’s top priority. The utility must also pay close attention to other factors while proceeding steadily with reactor decommissioning, such as reducing the risks of environmental pollution. It is also crucial for the company to explain the situation to local residents as well as the general public and heed their voices.
 
However, some within the NRA, as well as the Nuclear Reform Monitoring Committee, a group of domestic and overseas experts who advise TEPCO’s board of directors, have frequently expressed concern that TEPCO may start prioritizing its corporate profitability.
 
For TEPCO, which has been bailed out effectively under government control, decommissioning the reactors at the Fukushima No. 1 plant should be its foremost task. As the very party that allowed the nuclear disaster to occur, it is obviously its responsibility to invest sufficient capital and manpower in this undertaking.
 
In 2013, when Tokyo was bidding for the 2020 Olympics, Prime Minister Shinzo Abe declared in his speech that the issue of contaminated water at the Fukushima plant was “under control.”
 
But such optimism was hardly warranted, given the difficulty that became clear in disposing of the radioactive water.
 
This must be firmly borne in mind by TEPCO, as well as the Ministry of Economy, Trade and Industry, which oversees the utility, and the NRA.
 

March 16, 2018 Posted by | Fukushima 2018 | , | Leave a comment

Seven years on, no end in sight for Fukushima’s long recovery

March 11, 2018
Japan faces myriad challenges to decommissioning and decontamination
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Removing nuclear fuel from the Fukushima Daiichi power plant will take 30 to 40 years, ‘Tepco says’.
 
TOKYO — After helping shape nuclear policy in post-Fukushima Japan, Shunichi Tanaka, a former chief of the country’s nuclear watchdog, took on another tough assignment — moving to a village still struggling from the 2011 nuclear disaster to help with its recovery effort.
 
In February, Tanaka, who chaired the Nuclear Regulation Authority until last September, became a reconstruction adviser in the tiny village of Iitate, Fukushima Prefecture. Like many in surrounding localities, Iitate residents were ordered to evacuate after a powerful earthquake and tsunami on March 11, 2011, led to meltdowns at Tokyo Electric Power Co. Holdings’ Fukushima Daiichi nuclear power plant. To date, only around 10% of residents have returned.
 
“It won’t be easy to make life like it was before the disaster,” Tanaka said. Nonetheless he will help the village move forward by offering advice on nuclear decontamination and the ongoing dangers of radiation. He also acts as a go-between for the village and the national government.
 
“I’m a jack of all trades,” he says.
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Shunichi Tanaka, former chairman of the Nuclear Regulation Authority.
In his former role at the NRA, Tanaka spearheaded an overhaul of Japan’s nuclear regulatory scheme, setting tough new standards for nuclear power operations intended to prevent another Fukushima-like accident. To date, 12 reactors have cleared the new standards. And yet the public remains largely distrustful of nuclear power — a problem Tanaka believes he can address by building up trust in the areas directly affected by the Fukushima disaster.
 
Challenges in that region, however, remain immense, none more so than decommissioning the damaged power plant. This involves the unprecedented feat of removing and safely storing the plant’s nuclear fuel, part of which has melted and escaped from the reactors it originally powered.
 
Back in September, Tepco and the national government reaffirmed their previous timeline for the cleanup, estimating the decommissioning process would take 30 to 40 years to complete. But the herculean nature of this task is becoming increasingly apparent. Nuclear fuel is too radioactive for humans to approach even when wearing protective gear, and must be handled by remotely controlled robots. But precision machinery is sensitive to radiation, and developing technology able to withstand conditions at the Fukushima site has proved intensely challenging.
 
“I truly cannot say” whether decommissioning can be wrapped up on a 30- to 40-year timeline, and “it is important to be honest,” said Hajimu Yamana, head of the government-backed Nuclear Damage Compensation and Decommissioning Facilitation Corporation.
 
The process is also extremely costly. The Ministry of Economy, Trade and Industry in 2016 pegged costs such as decommissioning and victims’ compensation related to the disaster at 21.5 trillion yen ($202 billion at current rates), nearly double its initial estimate of 11 trillion yen.
 
Work to remove and store melted fuel, set to begin as soon as 2021, and assorted other decontamination tasks could pile on additional expenses, depending on how they progress. The Japan Center for Economic Research believes the real cost could be as high as 70 trillion yen. Much of this would be borne by taxpayers, who require a convincing explanation of why costs are so high.
 
Decontaminating the soil poses another thorny problem. Roughly 640,000 cu. meters of contaminated soil, divided into 1-cu.-meter packages, has been delivered to an interim government storage facility between October and January. Yet up to 22 million cu. meters of contaminated earth remains to be treated in Fukushima Prefecture alone, a far larger amount than can be adequately handled at the current pace of work.
 
The government has not even locked down the roughly 1,600 hectares of land needed to complete the facility, which is itself only a temporary solution. Tokyo has pledged that Fukushima Prefecture will not be the final resting place for any of this soil, and looks to move it to a more permanent home elsewhere within 30 years. But even initial steps toward choosing such a site remain to be taken.
 
“It would be difficult and unrealistic to ask other prefectures to shoulder the burden,” Tanaka said. He has proposed decontaminating the soil and using it to fill in wetlands, turning them into farmland or meadowland that would provide a living for residents returning to evacuated areas. An influx of foreign engineers working on decommissioning the Fukushima plant could also give rise to new industry. But whatever plans emerge, the highest and most important hurdle could be simply getting started.
 

March 15, 2018 Posted by | Fukushima 2018 | , , , | Leave a comment

Decommissioning Fukushima reactors will take time but progress continues

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In this July 27, 2017 file photo, contaminated water storage tanks are seen on the Fukushima No. 1 nuclear plant grounds, in Okuma, Fukushima Prefecture
 
March 11, 2018
Over the past year, clumps appearing to be melted fuel debris have been found inside three reactors at Tokyo Electric Power Co. (TEPCO)’s Fukushima No. 1 Nuclear Power Plant — which will soon mark seven years since being struck by disaster, on March 11.
 
However, the specific properties of the fuel debris remain unclear, and the decision on how to go about extracting the material has been delayed. The mammoth task of decommissioning the nuclear power plant, which is expected to take 40 years, is moving at a sluggish pace.
 
Removing the debris is the most difficult part of the decommissioning process. During an internal probe of nuclear containment vessels at the site, which involved robots, debris-like clumps were discovered in the No. 2 and No. 3 reactors, and sand-like sediment was found spread across the bottom of the No. 1 reactor. However, the specific properties and distribution of the debris has not yet been ascertained.
 
In September 2017, the government and TEPCO re-examined its decommissioning operation schedule. Initially, it was planned that the reactor which would undergo decommissioning first, as well as the method, would be decided by the end of the first half of fiscal 2018. However, the decision was delayed until the end of fiscal 2019 due to a lack of information concerning the situation inside the reactors, as well as the debris.
 
Meanwhile, as part of countermeasures against contaminated water, an ice wall designed to block the flow of underground water has almost been completed. In addition, a sub-drain well that pumps away subterranean water has been reinforced. As a result, the volume of underground water flowing into the buildings housing the reactors has been reduced from roughly 400 metric tons per day, which was the figure immediately after the outbreak of the disaster, to about 80 tons per day — indicating that there has been some progress regarding the “entrance” policy designed to reduce the volume of contaminated water generated at the site.
 
However, the “exit” policy, designed to dispose of treated water after most of the radioactive materials have been removed from the contaminated water, is still up in the air. The major issue concerning this policy is that the radioactive material tritium (tritiated hydrogen) cannot be removed, in principle, from treated water.
 
Tritium is something that appears in the natural world. Based on the fact that it has been flowing out into the sea from nuclear facilities across the globe, the Nuclear Regulation Authority stresses that Fukushima’s treated water containing tritium should be diluted and flushed out into the sea. However, due to fears that this could damage the reputation of the local fishing industry, the government and TEPCO continue to keep the treated water stored in tanks.
 
As a result, the amount of radioactive water stored at the site, including the treated water, has risen to about 1.05 million tons, and the number of tanks has increased to roughly 850. The government has set up a committee looking into how to dispose of the treated water, but consensus has not yet been reached.
 
Meanwhile, with regard to the extraction of fuel from pools of spent nuclear fuel, removal is planned from the No. 1 and No. 2 reactors in fiscal 2023, three years later than initially scheduled, and from the No. 3 reactor sometime around mid-FY2018. Special cranes are being installed to prepare for the job.
 

March 15, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Debris to be removed from side of Fukushima reactors

_w850.jpgWorkers wearing protective suits and masks work on the No. 2 reactor building at the Fukushima Daiichi nuclear power plant.

 

TOKYO – A state-backed entity tasked with supporting the decommissioning of the Fukushima nuclear power station proposed Thursday that melted fuel be removed from the side of three of the crippled reactors as part of the process to scrap the complex.

Based on a formal proposal, the government and the plant operator Tokyo Electric Power Company Holdings Inc (TEPCO) will determine specific approaches to carry out the process on each reactor next month and update the plant decommissioning road map.

Under its strategic plan for 2017, the Nuclear Damage Compensation and Decommissioning Facilitation Corp called for the removal of the fuel by partially filling the three reactors with water to cover some of the nuclear debris while allowing access to carry out the work.

The entity also pointed out that the decommissioning work requires phased efforts while maintaining flexibility, as the project still faces many uncertainties.

The extraction work from the Nos. 1-3 reactors at the Fukushima Daiichi nuclear complex, which suffered meltdowns following the massive 2011 earthquake and tsunami disaster, is seen as the most difficult step toward the ultimate goal of decommissioning the entire complex, set to take at least 30 to 40 years to complete.

The government and TEPCO are currently aiming to start the extraction work from 2021.

Under the plan, the Nuclear Damage Compensation and Decommissioning Facilitation body proposed using a remotely controlled apparatus to shave debris from the underside of the lower section of the reactors’ containment vessel while controlling the level of water.

Debris remains not only in the reactors’ pressure vessel but also piled and scattered at the bottom of the containment vessel that houses the reactor vessel.

As for debris left in the reactors’ pressure vessel, the entity will consider removing it from the upper part of the reactors, it said.

The decommissioning body had previously considered a strategy to fill the containment vessel with water as water is effective in containing radiation, but it has shelved the idea as the reactor containers are believed to have been damaged and would leak.

Following a magnitude-9.0 earthquake in March 2011, tsunami inundated the six-reactor plant, located on ground 10 meters above sea level, and flooded power supply facilities.

Reactor cooling systems were crippled and the three reactors suffered fuel meltdowns, while hydrogen explosions damaged the buildings housing the Nos. 1, 3 and 4 reactors.

The Nuclear Damage Compensation and Decommissioning Facilitation entity was established after the Fukushima crisis, the worst nuclear disaster since Chernobyl, to help the utility pay damages. The state-backed entity holds a majority stake in the operator.

https://japantoday.com/category/national/Debris-to-be-removed-from-side-of-Fukushima-reactors

September 2, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Muscle robots’ being developed to remove debris from Fukushima reactors

Hitachi-GE testing variety of simply structured, radiation-resistant equipment

20170818_Fukushima-reactor_article_main_image.jpgThe Unit 1 reactor building at the Fukushima Dai-ichi nuclear power plant of the Tokyo Electric Power Co. (TEPCO) in Okuma town, Fukushima prefecture, June 21, 2017.

 

TOKYO — A joint venture between Japanese and American high-technology power houses Hitachi and General Electric is developing special robots for removing nuclear debris from the Fukushima Daiichi nuclear power plant, the most difficult task in decommissioning the plant’s six reactors, three of which suffered core meltdowns in the March 2011 accident.

The machines under development by Hitachi-GE Nuclear Energy are called “muscle robots,” as their hydraulic springs operate like human muscles. The company, based in Hitachi, Ibaraki Prefecture, is stepping up efforts to complete the development project in time for the start of debris removal in 2021.

Hitachi-GE is testing the arms of the robots at a plant of Chugai Technos, a Hiroshima-based engineering service company, located a 30-minute drive from the center of the city. The testing is taking place in a structure with a life-size model of the primary containment vessel of the No. 1 reactor at the Fukushima plant. The robots awkwardly move about, picking up concrete lumps standing in for fuel debris.

“The robots are based on a concept completely different from those of conventional robots,” said Koichi Kurosawa, a senior Hitachi-GE engineer heading the development project. Hydraulics are being used because electronics cannot survive in the extreme environment inside the reactors.

“Asked if the robots are applicable to other nuclear power plants, I would say the possibility is low,” Kurosawa said, noting that the robots are designed to work amid intense radiation.

New challenges

While Hitachi-GE has built many nuclear reactors, it is encountering a variety of new challenges in developing the muscle robots simply because of the tough work required to retrieve fuel debris.

In the nuclear accident caused by the March 2011 earthquake and tsunami, cooling the fuel rods became impossible, and melted uranium fuel dropped from them. Some of the fuel broke through nuclear reactor pressure vessels and solidified as fuel debris containing uranium and plutonium.

The debris is estimated to weigh more than 800 tons in total. The insides of the PCVs at the Fukushima plant are directly exposed to the debris and are emitting radioactivity strong enough to kill a human within a few minutes.

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The International Research Institute for Nuclear Decommissioning, a Tokyo-based research institute for decommissioning nuclear plants, and three reactor makers — Hitachi-GE, Toshiba and Mitsubishi Heavy Industries — have been attempting to ascertain conditions inside the reactor buildings at the Fukushima plant by means of camera- and dosimeter-equipped equipment.

https://asia.nikkei.com/Tech-Science/Science/Muscle-robots-being-developed-to-remove-debris-from-Fukushima-reactors

September 2, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Fukushima nuke plant decommissioning still has long way to go

 

Mainichi Shimbun reporters visited the Fukushima No. 1 Nuclear Power Plant on July 27. While the working environment at the station has improved, plant operator Tokyo Electric Power Co. (TEPCO) still has a mountain of problems to tackle, such as removing melted nuclear fuel from the No. 1 to No. 3 reactors and treating contaminated water.

https://mainichi.jp/english/articles/20170811/p2a/00m/0na/025000c

August 14, 2017 Posted by | Fukushima 2017 | , | Leave a comment

Japan’s nuclear safety chief raps Tepco’s attitude on Fukushima No. 1 crisis, restarting other reactors

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The head of the Nuclear Regulation Authority told Tepco’s top management he questions their attitude toward decommissioning the Fukushima No. 1 nuclear power plant and the company’s ability to resume operating its other reactors.

I feel a sense of danger,” NRA Chairman Shunichi Tanaka said during a special meeting Monday with the top management of Tokyo Electric Power Company Holdings Inc.

Tanaka also said Tepco does “not seem to have the will to take the initiative” toward decommissioning the crippled nuclear power station that suffered three reactor meltdowns in March 2011.

Tepco Chairman Takashi Kawamura and President Tomoaki Kobayakawa attended the meeting. The authority felt it is necessary to hear from the top executives before it could make a decision on whether to approve Tepco’s plan to resume operation of reactors 6 and 7 at its massive Kashiwazaki-Kariwa plant in Niigata Prefecture.

Tepco filed for a safety assessment of the two reactors in September 2013 to reactivate them, hoping to restore its financial condition as it needed massive funds to pay compensation related to the Fukushima disaster and to scrap the plant.

The NRA’s safety screening found that Tepco failed to report insufficient earthquake resistance for an emergency response center at the Niigata complex even though it knew about the insufficiency for three years.

In June, Tepco submitted to the watchdog its revised safety measures for the Kashiwazaki-Kariwa complex.

An operator lacking the will to take the initiative does not have the right to resume operation of nuclear reactors,” Tanaka said.

Tepco’s chairman responded by saying: “There are citizens who believe nuclear power is necessary. Operating reactors is our responsibility.”

But Kawamura also admitted there is room for only two more years’ worth of space in the tanks to accommodate the contaminated water building up at Fukushima No. 1.

During the meeting the NRA asked Tepco’s management about the company’s safety measures for the Niigata complex — the biggest nuclear power station in the world — as well as its safety awareness.

Tanaka said the NRA does consider Tepco’s responses at the meeting as sufficient and requested that it submit further explanations on its plan to decommission Fukushima No. 1 and resume operation of the two reactors at Kashiwazaki-Kariwa.

Tanaka plans to conduct on-site checkups at the two reactors, saying, “Tepco, which caused the (Fukushima) accident, is not an ordinary operator.”

The two boiling water reactors at the Niigata plant are the same type that suffered core meltdowns at Fukushima No. 1, and no such reactors have cleared the authority’s safety screening since the 2011 crisis.

http://www.japantimes.co.jp/news/2017/07/10/national/japans-nuclear-safety-chief-raps-tepcos-attitude-fukushima-no-1-crisis-restarting-reactors/

July 10, 2017 Posted by | Fukushima 2017 | , , , , | Leave a comment

TEPCO vows decommissioning of Fukushima N-plant

A TEPCO logo is pictured on a sign showing the way to the venue of the company's annual shareholders' meeting in Tokyo

FUKUSHIMA (Jiji Press) — The new leaders of Tokyo Electric Power Company Holdings Inc. told Fukushima Gov. Masao Uchibori on Monday of their resolve to promote the decommissioning of the company’s disaster-crippled Fukushima No. 1 nuclear power plant.

There is no change at all that Fukushima is our basic focus,” TEPCO Chairman Takashi Kawamura said to Uchibori at a meeting in the prefectural government office, after explaining that TEPCO’s new management team was launched after approval at a general meeting of its shareholders on Friday.

Kawamura said, “We will proceed safely and steadily with the decommissioning work for the Fukushima No. 1 plant,” where a serious nuclear accident occurred after the March 2011 major earthquake and tsunami in northeastern Japan. The prefecture hosts the plant.

Meanwhile, Uchibori said the people of Fukushima Prefecture strongly want all reactors at TEPCO’s Fukushima No. 2 nuclear power plant, also located in the prefecture, to be decommissioned, the same as they want the decommissioning of the Fukushima No. 1 plant and the implementation of accident compensation plans.

Since the 2011 disaster, TEPCO has halted all four reactors at the No. 2 plant. The Fukushima prefectural assembly and the assemblies of all 59 municipalities in Fukushima have adopted resolutions calling on the company to decommission the No. 2 plant or taken similar steps.

http://the-japan-news.com/news/article/0003784590

June 26, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Decommissioning of Monju Fast-Breeder Reactor Accepted by Fukui Governor

Capture du 2017-06-07 23-03-30.pngThe Monju prototype fast-breeder reactor in Tsuruga, Fukui Prefecture

 

Fukui governor accepts decision to decommission Monju reactor

Fukui Governor Issei Nishikawa has ditched his opposition to the central government’s plans to decommission the Monju prototype fast-breeder reactor in his prefecture.

Nishikawa had criticized Tokyo for deciding to decommission the reactor in Tsuruga without offering adequate assurances to local residents about such a massive project.

But during a meeting held at the prime minister’s office in Tokyo early June 7, he said, “Decommissioning of the Monju fast-breeder reactor is inevitable.”

At the meeting, attended by relevant Cabinet ministers, the government presented Nishikawa with a basic policy to remove spent nuclear fuel from the reactor in five and a half years and complete decommissioning in 30 years.

Hirokazu Matsuno, the science and technology minister, explained that the basic policy includes a plan to transfer spent nuclear fuel outside the prefecture as demanded by Fukui prefectural authorities.

The government will soon formally adopt the basic policy on decommissioning. The Japan Atomic Energy Agency, which operates the Monju reactor, will then draft its own plan for the project.

The government decided to decommission Monju at the end of last year and was initially expected to present the basic plan in April. However, Nishikawa had been airing concerns about the decommissioning.

http://www.asahi.com/ajw/articles/AJ201706070036.html

Fukui governor approves scrapping of Monju reactor

The governor of Fukui in central Japan has consented to dismantling the prototype fast-breeder nuclear reactor in the prefecture.
The Japanese government decided in December to scrap the Monju reactor over a period of 30 years, following a series of safety management problems. It cited rising costs.
Governor Issei Nishikawa had opposed the plan, expressing concerns about the safety of the dismantling process.
Nishikawa met with Chief Cabinet Secretary Yoshihide Suga and science minister Hirokazu Matsuno on Wednesday in Tokyo.
Matsuno explained the basic plan for scrapping the reactor. The science minister said spent nuclear fuel and sodium coolant would be moved out of the prefecture in future.
He also said the government will come up with a development plan for the host city of Tsuruga by the next fiscal year. He said this would make the city a hub of nuclear research and personnel training.
Governor Nishikawa said he confirmed the government’s basic plan for decommissioning and revitalizing the community. He said he had no choice but to accept the decommissioning. He emphasized that the process be carried out safely.

https://www3.nhk.or.jp/nhkworld/en/news/20170607_15/

June 9, 2017 Posted by | Japan | , , | Leave a comment

Submersible Crawling Robot to Examine Interior of Fukushima Daiichi-3 PCV before Fuel Debris Is Removed

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On May 25, the Tokyo Electric Power Co. (TEPCO) released a status report on the ongoing decommissioning work at the Fukushima Daiichi Nuclear Power Plants, which suffered a tsunami-caused meltdown in March 2011.

Starting two months ago, in March, a self-propelled robot has been used to investigate the interior of the primary containment vessel (PCV) of Unit 1 at Fukushima Daiichi—a necessary step before fuel debris can be removed. As of April 6, the robot had sampled deposits twice.

Fluorescent X-ray spectroscopy has now confirmed the presence of elements that had originally existed in the PCV, such as iron and nickel within the reactor core internals, stainless steel in the heat-insulating materials, zinc in the paint, and lead in the shielding materials.

Although uranium was confirmed as the primary radioactive nuclide within Unit 1, it is not necessarily part of the fuel debris there, given that that element exists naturally. TEPCO said that it would carry out more detailed analyses to confirm the uranium’s source.

As the water level in the PCV of Unit 3 is higher than that in Units 1 and 2, its so-called “X-6 penetration”—which would give easier access to the inside of the pedestal (under the reactor pressure vessel)—is submerged. TEPCO plans to investigate the interior of that unit’s PCV at an undetermined date this summer using a submersible robot that can both crawl and swim. Earlier this month, the power utility began taking measurements using muon observation technology to determine the location of fuel debris.

Under the “Mid-and-Long-Term Roadmap” toward decommissioning, TEPCO will determine policies on fuel debris removal at each Fukushima Daiichi unit this summer. According to its May 22 report to an expert panel of the Nuclear Regulation Authority (NRA), the power company has already made investigations to determine general conditions inside the individual PCVs.

TEPCO will continue to focus on gathering information during the current fiscal year (ended March 31, 2018), including that on the forms and distribution of fuel debris—necessary to determine the means to remove it—and safety measures for the actual removal work.

http://www.jaif.or.jp/en/submersible-crawling-robot-to-examine-interior-of-fukushima-daiichi-3-pcv-before-fuel-debris-is-removed/

 

June 5, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Where to put all the radioactive waste is now the burning issue

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The call might have been made to decommission five over-the-hill nuclear reactors, but the problem remains of where to dispose of their total 26,820 tons of radioactive waste.

The plant operators have yet to find disposal sites, and few local governments are expected to volunteer to store the waste on their properties.

The decommissioning plans for the five reactors that first went into service more than 40 years ago was green-lighted by the Nuclear Regulation Authority on April 19.

It is the first NRA approval for decommissioning since the 2011 Fukushima nuclear disaster triggered by the Great East Japan earthquake and tsunami.

That disaster led to a new regulation putting a 40-year cap, in principle, on the operating life span of reactors.

The reactors to be decommissioned are the No. 1 reactor at Japan Atomic Power Co.’s Tsuruga plant in Fukui Prefecture; the No. 1 reactor at Kyushu Electric Power Co.’s Genkai plant in Saga Prefecture; the No. 1 and No. 2 reactors at Kansai Electric Power Co.’s Mihama plant in Fukui Prefecture; and the No. 1 reactor at Chugoku Electric Power Co.’s Shimane plant in Shimane Prefecture.

The decommissioning will be completed between fiscal 2039 and fiscal 2045 at a total cost of 178.9 billion yen ($1.64 billion), according to the utilities.

In the process, the projects are expected to produce 26,820 tons of radioactive waste–reactors and pipes included.

An additional 40,300 tons of waste, such as scrap construction material, will be handled as nonradioactive waste due to radiation doses deemed lower than the government safety limit.

Securing disposal sites for radioactive waste has proved a big headache for utilities.

About 110 tons of relatively high-level in potency radioactive waste, including control rods, are projected to pile up from the decommissioning of the No. 1 reactor at the Mihama plant.

Such waste needs to be buried underground deeper than 70 meters from the surface and managed for 100,000 years, according to the NRA’s guidelines.

In addition, the decommissioning of the same reactor will generate 2,230 tons of less toxic waste as well, including pipes and steam generators.

Under the current setup, utilities must secure disposal sites on their own.

Kansai Electric, the operator of the Mihama plant, has pledged to find a disposal site “by the time the decommissioning is completed.”

But Fukui Prefecture, which hosts that plant and others, is demanding the waste from the Mihama facility be disposed of outside its borders.

The project to dismantle the reactor and other facilities has been postponed at Japan Atomic Power’s Tokai plant in Ibaraki Prefecture because the company could not find a disposal site for the relatively high-level waste.

The decommissioning of the reactor had been under way there since before the Fukushima disaster.

The expected difficulty of securing disposal sites could jeopardize the decommissioning timetable, experts say.

Even finding a disposal site for waste that will be handled as nonradioactive has made little headway.

What is more daunting is the hunt for a place to store high-level radioactive waste that will be generated during the reprocessing of spent fuel, they said.

http://www.asahi.com/ajw/articles/AJ201704200039.html

April 20, 2017 Posted by | Japan | , , | Leave a comment

Japan to scrap 5 more nuclear reactors

String of facilities approaching maximum life span

0420N-Decommissioning-Business_article_main_image.jpgWorkers take apart a pump at Chubu Electric Power’s Hamaoka nuclear plant.

TOKYO — Five nuclear reactors in Japan were approved for decommissioning on Wednesday, pushing utilities and other companies to join hands to tackle both the great business opportunities and daunting technical problems involved with the process.

Two reactors at Kansai Electric Power‘s Mihama plant, as well as one each at Japan Atomic Power’s Tsuruga plant, Chugoku Electric Power‘s Shimane plant and Kyushu Electric Power‘s Genkai facility received the green light from Japan’s Nuclear Regulation Authority. The safety updates needed to keep them running beyond their mandated 40-year life span were deemed too costly.

Japan had 54 nuclear reactors before the 2011 meltdown at the Fukushima Daiichi nuclear plant. A total of 15, including the six at Fukushima Daiichi, are now set to be taken out of service. Another one or two will be brushing up against the 40-year limit every year, unless one-time, 20-year extensions are sought and granted.

Companies now face a pressing need to acquire expertise on dismantling reactors and disposing of radioactive materials. No commercial nuclear reactor has ever been decommissioned in Japan before, and utilities are looking for partners with the necessary capabilities.

Kansai Electric is seeking help from France’s Areva and Japan’s Mitsubishi Heavy Industries in decommissioning the Nos. 1 and 2 reactors at Mihama, particularly in decontaminating pipes and equipment. Japan Atomic Power and U.S.-based EnergySolutions signed an agreement last spring to cooperate on the former’s Tsuruga plant.

Japanese utilities are also beginning to work with each other. Kansai Electric entered a partnership last year with Kyushu Electric, Chugoku Electric and Shikoku Electric Power. The four plan to cut decommissioning costs by jointly procuring materials and sharing technology and staffers. 

Other players are also angling for a piece of the pie. Two years ago, Mitsubishi Heavy set up a department specializing in dismantling nuclear reactors. The company was a key player in building the Mihama and Genkai reactors, and wants a lead role in taking them apart. Japanese general contractor Shimizu also signed a technical cooperation agreement with U.K.-based Cavendish Nuclear.

Utilities have increased their rates in order to raise the necessary funds to decommission the five newly approved reactors. They have already come up with about 160 billion yen ($1.47 billion) of the estimated 180 billion yen total. But the process will likely take two or three decades, and costs could easily grow.

The utilities may also face significant challenges to disposing of the roughly 27,000 tons of contaminated waste the five reactors are expected to generate. For example, Japan Atomic Power wants to bury less radioactive materials at the site of the Tokai nuclear plant, one of the earlier plants approved for decommissioning, but faces strong local opposition.

Relevant legislation has not been finalized either. Highly contaminated materials are supposed to be buried more than 70 meters below ground. But the Nuclear Regulation Authority has only just begun debating exactly how they should be buried.

http://asia.nikkei.com/Politics-Economy/Policy-Politics/Japan-to-scrap-5-more-nuclear-reactors

April 20, 2017 Posted by | Japan | , | Leave a comment

Robots expected to play key role in Fukushima decommissioning, but challenges remain

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As decommissioning work at Tokyo Electric Power Co. (TEPCO)’s Fukushima No. 1 Nuclear Power Plant continues, remote control robots are expected to play an important role in the decommissioning process. However, it is impossible to ignore the fact that the development of these robots faces huge challenges, such as high levels of radiation within the nuclear reactors, as well as a lack of information.

Among the robots that have been designed to carry out decommissioning work is the “muscle robot.” Developed by Hitachi-GE Nuclear Energy, Ltd., the body and limbs of the muscle robot can be controlled with a device that one might typically find attached to a video game console. Another type of robot acts like a crab with claws that can be used to grasp metallic pipes and snap them using a blade positioned on one of its claws. These robots are also able to smash concrete, using a special drill that can be placed at the end of the arm — like something out of a Hollywood movie.

Looking ahead, the government and TEPCO are aiming to start removing the melted nuclear fuel inside the No. 1 to No. 3 reactors at the Fukushima No. 1 nuclear plant in 2021, after announcing exactly how they plan to do so over the summer. Although knowledge regarding the matter is limited, it seems that the melted nuclear fuel in the reactors has cooled and solidified, and the prototypes of the robots have been produced based on the assumption that the devices need to break down and remove such hardened fuel.

The robots’ parts are connected together with springs, and are driven using hydraulic power. One of the main advantages of this system is that they are hardly affected by radiation. There are six types of robot in total, such as the “spider-style” robot which has six arms and legs (length 2.8 meters, width 2 meters, weight 50 kilograms), as well as a “tank-style” robot (length 4.35 meters, width 63 centimeters, weight 700 kilograms), which runs on a conveyor belt. The tank-style robot is capable of lifting objects weighing up to 50 kilograms. A representative from Hitachi-GE Nuclear Energy states determinedly, “I want the muscle robots to remove the melted nuclear fuel.”

However, the process will not be plain sailing. While the bodies of these robots are resistant to radiation, their cameras are somewhat vulnerable. It has been found that the electronic hardware in the cameras breaks easily after being exposed to radiation. For example, when a “cleaning robot” was sent into the No. 2 reactor on Feb. 9, 2017, the camera broke after about two hours after being exposed up to an estimated 650 sieverts per hour of radiation. The camera part of the robot is essential because without it, images cannot be transmitted back to the control room.

To solve this problem, ideas such as placing a metallic plate near the camera that would block out radiation have been discussed, but it is feared that this would make the robot heavier and interfere with its operations. As a Hitachi representative states, “If one were to use an analogy to describe the current development stage in human terms, then we have entered elementary school. We’d like to continue our work, believing we can develop usable robots.” It is clear that a trial-and-error process is very much underway, as the robot developers try their best to achieve perfection.

It will not be an easy road though. Hajime Asama, professor at the University of Tokyo and a member of the Technology Advisory Committee of the International Research Institute for Nuclear Decommissioning (IRID), states, “Robots are usually developed based on confirmation of what exactly lies in the reactors. However, in the case of the No. 1 power plant, no matter how hard you try to predict what is in there, there are often unexpected elements waiting.”

In the No. 2 reactor, a “scorpion-style robot” was sent in on Feb. 16, as a follow-up to the cleaning robot but it got trapped by deposits on the conveyor belt, and came to a halt. The presence of these kinds of deposits was unexpected at the stage when the robot was being designed. Too much is still unknown about the situation inside the reactors, making robot design difficult. Later this month, a “wakasagi ice fishing-type robot” is expected to be placed inside the No. 1 reactor, but it is feared that the same problems that were experienced in the No. 2 reactor will emerge once again.

In recent years, the use of artificial intelligence has been expected to play a key role but a number of unexpected problems have made progress in this area difficult. What is needed is technology that can be controlled remotely by people with flexible judgment. However, professor Asama believes that, “The reactors inside the No. 1 plant are full of unknown challenges. We have no choice but to use our available knowledge to create robots that can deal with these problems.”

https://mainichi.jp/english/articles/20170408/p2a/00m/0na/023000c

April 9, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

TEPCO to decommission 1 reactor at Fukushima No. 2 plant, mulling fate of 3 others

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Tokyo Electric Power Company Holdings Inc. (TEPCO) has informally decided to decommission the No. 1 reactor at its Fukushima No. 2 Nuclear Power Plant, it has been learned.

In the wake of the March 2011 Great East Japan Earthquake and tsunami and ensuing meltdowns at the Fukushima No. 1 plant in Fukushima Prefecture, local bodies and residents of the area who suffered extensive damage requested that all four reactors at the No. 2 plant also be decommissioned.

TEPCO had avoided stating a clear position on the No. 2 plant’s reactors, but there had been pressure from the government and ruling coalition for it to make a decision. The company accordingly decided to decommission the plant’s No. 1 reactor, which suffered the most damage, and will consider what to do with the other three reactors in the future.

The No. 1 reactor of the Fukushima No. 2 plant began operating in 1982. It was flooded by tsunami on March 11, 2011, and all four reactors at the plant remain idled. The No. 2 plant suffered less damage than the No. 1 plant, and if it passed screening by the Nuclear Regulation Authority, its reactors could be restarted. But the Fukushima Prefectural Government and all 59 local assemblies have asked TEPCO and the government to decommission all reactors in the prefecture.

TEPCO has remained busy handling compensation claims relating to the Fukushima nuclear disaster and the disaster cleanup. If it were to decommission all of the No. 2 plant’s reactors, they would lose value and it would have to write down huge losses. Company president Naomi Hirose has therefore avoided taking a clear position on the issue, saying, “I would like to consider it and make a decision as a business operator.”

Last year, however, officials decided to create a fund to cover the huge cost of handling the nuclear disaster, which is expected to reach 21.5 trillion yen, nearly double the original prediction. There was accordingly pressure from the government for TEPCO to reach an early decision on the fate of the No. 2 plant’s reactors.

The No. 1 reactor at the No. 2 plant is the oldest of the plant’s four reactors. It temporarily lost its cooling functions in the March 2011 disaster, and suffered the most damage among the four reactors. TEPCO believes that by limiting decommissioning to one reactor for the time being, it will be able to hold the decommissioning cost below 100 billion yen, minimizing the impact on company finances and on decommissioning work at the Fukushima No. 1 plant. However, a decision to decommission only one reactor at the No. 2 plant is unlikely to win public approval.

http://mainichi.jp/english/articles/20170317/p2a/00m/0na/024000c

March 20, 2017 Posted by | Fukushima 2017 | , , | Leave a comment