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The News That Matters about the Nuclear Industry

Lifting Fukushima evacuation orders

28 feb 2017

The lifting of evacuation orders in four municipalities around Tokyo Electric Power Co. Holding’s Fukushima No. 1 nuclear power plant over the weekend does not normalize the lives of former residents forced out of their hometowns due to the radioactive fallout from the March 2011 triple meltdowns at the plant. The government needs to keep up support for the residents — both those returning to their hometowns and those choosing to stay out for various reasons — to help them rebuild their lives, which were shattered by the nuclear disaster six years ago.

Since 2014, the government has been moving to lift its evacuation orders issued to areas once designated no-go zones around the Tepco plant where the level of radioactive pollution is deemed to have declined to acceptable levels through decontamination efforts. The lifting of the evacuation orders in parts of the Fukushima towns of Namie, Tomioka and Kawamata and Iitate village on Friday and Saturday paves the way for the return of about 32,000 former residents. The total areas designated as no-go zones have now been reduced to roughly one-third of their peak — although areas that used to be home to 24,000 people will continue to be off-limits to former residents due to still high radiation levels.

Last month, Prime Minister Shinzo Abe said reconstruction from the March 11, 2011, disasters — the Great East Japan Earthquake and tsunami and the nuclear fiasco — is making steady progress and is “entering a new stage” with the lifting of evacuation orders to the former no-go zones around the Tepco plant. Also at the end of March, public housing assistance was terminated for people who had voluntarily evacuated from areas located outside the no-go zones out of fear of radioactive pollution.

However, government decisions alone will not return evacuees’ lives to a state of normalcy. In areas where evacuation orders have earlier been lifted since 2014, only 13 percent of the former residents have returned to their hometowns. In Namie and Tomioka, where some parts of the towns will continue to remain off-limits due to high radiation levels, more than 50 percent of former residents told a Reconstruction Agency survey last year that they have no plans to return in the future.

Some of the former residents cite continuing concerns over the effects of radioactive contamination, while others point to the slow recovery of infrastructure crucial to daily life such as medical services and shopping establishments in their hometowns. Other former residents have started life anew in the places to which they have evacuated.

The prospect is also bleak for businesses that used to operate in the areas. According to a survey by the association of Fukushima Prefecture chambers of commerce and industry, about half of the companies located in the no-go zones were unable as of last September to reopen their businesses as they lost their customers and business partners in the years since the 2011 disaster. Many of the busineses that have reopened after the evacuation orders were lifted said they have not been able to earn the same level fo profits as before the nuclear crisis.

Reconstruction from the March 2011 disasters continues to lag in Fukushima compared with the other devastated prefectures of Miyagi and Iwate, because of the additional woes caused by the Tepco plant disaster. Nearly 80,000 Fukushima residents remain displaced from their homes six years on — roughly half the peak figure of 165,000 but still accounting for a bulk of the national total of 123,000 as of February.

With the lifting of the evacuation orders, monthly payments of consolation money from Tepco to the residents of former no-go zones will be terminated in a year. Fukushima Prefecture’s housing aid, essentially funded by the national government, to more than 20,000 Fukushima people who voluntarily evacuated from their homes outside the no-go zones was cut off at the end of last month — although substitute assistance programs will be continued on a limited scope.

Officials say that decontamination and restoration of social infrastructure have progressed in the former no-go zones around the Tepco plant. However, administrative decisions such as the lifting of evacuation orders alone will not compel evacuees to return to their hometowns or rebuild their communities shattered by the nuclear disaster. The government must keep monitoring the real-life conditions of residents in affected areas and extend them the support they need, as well as continue to improve crucial infrastructure so more evacuees feel they can return home.

http://www.japantimes.co.jp/opinion/2017/04/03/editorials/lifting-fukushima-evacuation-orders/

April 3, 2017 Posted by | Fukushima 2017 | , , , , , | Leave a comment

As I See It: Flawed gov’t policies betraying Fukushima disaster victims

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A demonstration takes place at Hibiya Park in Tokyo in March 2016, at which protesters express their distrust of the government which has failed to listen to the voices of Fukushima nuclear disaster victims.

Six years have passed since the disaster at Tokyo Electric Power Co. (TEPCO)’s Fukushima No. 1 Nuclear Power Plant, and the government’s policies for helping affected people are reaching the end of a chapter.

The government provision of housing to voluntary evacuees is coming to an end, and with the exception of a few selected areas, evacuation orders have been lifted or scheduled to be lifted soon. Compensation payments for such evacuees are scheduled to end, too — as these were given out in tandem with the evacuation orders.

With this kind of reality in mind, the “accelerated recovery” that was promoted by the government now just appears to be a hasty attempt to draw a curtain over the issue of evacuation from Fukushima. Government policies related to evacuation are seemingly one-way, and given that these policies have failed to gain the acceptance of affected residents, it can be said that they are corroding away at the core of democracy.

Over the past few years, I have continued to cover the situation in Fukushima using data such as health surveys, polls of voluntary evacuees, housing policies, and decontamination — with the aim of chasing after the real intentions of the creators of government policies. And yet, even though the government organizations and bureaucrats that are in charge differ depending on the issue, discussions go on behind closed doors, after which decisions are forced on the public that are completely out of touch with the needs of those affected. These kinds of policymaking procedures are all too common.

There are also cases of double standards. For example, the government had set the maximum annual limit of radiation exposure at 1 millisievert per year for regular people but immediately after the 2011 Fukushima nuclear disaster, the figure was raised to 20 millisieverts per year as the yardstick for evacuation “because it was a time of emergency.”

Later, in December 2011, a “convergence statement” was released by then Prime Minister Yoshihiko Noda in which he announced that the “emergency period” was over. Restructuring of the evacuation orders was subsequently carried out, and then the new criteria for relaxing such instructions were discussed in private.

From April 2013 onward, closed-door discussions continued to take place among section chiefs and other officials from organizations such as the Ministry of Economy, Trade and Industry and the Reconstruction Agency. They then waited until after the House of Councillors election in July 2013 to announce that areas where the annual radiation exposure was less than 20 millisieverts per year would be exempted from the evacuation orders. A source told me that the timing of the announcement was set as “not to trouble the government.” In other words, the level of 20 millisieverts per year had switched from “the time of emergency level” to “the ordinary level,” and it was as though the previous 1 millisievert annual level for ordinary situations had been banished from history.

Nearly four years have passed since then. At an explanatory meeting for evacuees from the Fukushima Prefecture towns of Namie and Tomioka, hardly anyone agreed with the lifting of the evacuation order this coming spring. It’s clear in the term “unnecessary exposure to radiation,” often used by the Fukushima evacuees, that there is absolutely no reason for local residents to endure radiation exposure caused by the nuclear disaster. And it’s understandable that they have difficulties accepting policies that ignore the voices of those from the affected areas.

Another problem is government bodies’ practice of blurring responsibilities by deleting inconvenient elements in records of the closed-door decision making process, thereby making it impossible for third parties to review the process afterwards.

The government was planning to complete the majority of the decontamination work by the end of fiscal 2016. In June 2016, the Environment Ministry devised a plan for reusing the contaminated soil whose volume has ballooned due to the cleaning work. In a closed-door meeting with specialists, the ministry also set the upper contamination level limit for reusing the soil at 8,000 becquerels per kilogram. However, with regard to the reuse of waste generated from decommissioning work such as iron, the upper limit is set at 100 becquerels. What officials talked about in that closed-door meeting was how to make that kind of double standard appear consistent.

In June 2016, the Mainichi Shimbun reported this matter, and as a number of freedom-of-information requests were filed, the Environment Ministry decided to release the relevant records. Ministry officials claimed that they were making all the information public. However, they had deleted statements by the bureaucrats in charge; statements that suggested the entire discussion had been undertaken with the 8,000 becquerel limit as a given.

Speaking on the issue of helping affected people, politicians and bureaucrats have repeatedly spouted rhetoric such as “staying beside disaster victims.” Despite this, however, there have been cases where senior officials from organizations such as the Reconstruction Agency have shown their true feelings through abusive statements via social media such as Twitter. In August 2015, Masayoshi Hamada, the then state minister for reconstruction, stated in private about the housing provision for Fukushima evacuees, “Basically, we are accepting residents based on the assumption that we don’t support those who evacuated voluntarily.”

Hamada was promoted to the position of state minister in December 2012 — at the same time as the launch of the second Cabinet of Prime Minister Shinzo Abe — and he was put in charge of supporting voluntary evacuees. For these evacuees, the housing provision policy was anticipated the most. Hamada’s irresponsible remarks, however, were almost equal to saying that the agency had no real intention of helping those who had evacuated of their own accord. I cannot help but wonder if politicians such as Hamada do in fact want to “stay beside disaster victims.”

The victims of the Fukushima nuclear disaster have always been kept on the other side of the mosquito net. The majority of policy discussions among the state and local governments concerning the affected people have taken place behind closed doors, and the records that have been released afterward have often been censored in order to conceal certain elements, with excuses such as “making these documents public could cause confusion.” In some of those closed door meetings, officials even talked about “how not to leak information.”

It might be stating the obvious, but unless information concerning policies is made public and there is transparency surrounding the decision making process, democracy cannot function. The way that the government has one-sidedly carried out its national policies by ignoring the voices of the Fukushima disaster victims, as well as people across Japan, poses risks to the very foundation of democracy. In some ways, this is one major part of the damage caused by the nuclear disaster.

http://mainichi.jp/english/articles/20170401/p2a/00m/0na/002000c

April 1, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Chinese parents seek refunds for Japan trip, citing radiation concerns

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Families of 40 choir members cancel Tokyo trip after travel advisory from Chinese embassy

Parents of a children’s choir in southern China are seeking refunds for a trip to a singing competition in Japan that they cancelled over concerns of radiation leaks.

Their requests to refund the training, travel and accommodation fees, which add up to 19,800 yuan (US$2.900)for each child, have been denied by the singing training centre of the Guangzhou Opera House, with which the choir is affiliated, Television Southern of Guangdong reported.

The concerned parents said each family paid fees to the training centre in January for training, visas, insurance and accommodation for the trip to Japan for an international choir competition in August.

Forty students signed up for the trip, the report said.

Many parents became worried a month later when the Chinese embassy in Tokyo issued a reminder of record-high radiation from the Fukushima nuclear plant, which has been leaking radioactivity since being badly damaged by an earthquake and tsunami in 2011.

The embassy statement cited a spokesperson from the Chinese Foreign Ministry in Beijing and urged Chinese tourists in Japan to make appropriate arrangements. The request for refunds was denied by the training centre, who insisted that parents would have to pay 20 per cent of costs, or about 4,000 yuan, to cancel the trip.

Many parents said that was unacceptable as health concerns should be of priority to the training centre as well as the families.

Some parents rallied in front of the training centre to raise attention to the issue, the report said.

The head of the choir said in a statement that the group was non-profit and he would personally ask for a full refund from the Opera House.

He said he had arranged a meeting to negotiate for the parents on Thursday.

Japan has become a popular travel destination for Chinese tourists in recent years after it eased visa rules for mainland tourists, who have flooded to their near neighbour where they spend up large on items that range from luxury watches to toilet seats.

http://www.scmp.com/news/china/society/article/2083086/chinese-parents-seek-refunds-japan-trip-citing-radiation-concerns

March 31, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Columban missionary backs bishops against nuclear industry after harrowing visit to Fukushima clean-up

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Evacuated: An evacuee rests in a gymnasium serving as an evacuation centre in Yamagata, Japan, in March 2011. Residents from the vicinity of Fukushima Dai-ichi nuclear power plant were sheltered at the gym, as officials and workers struggled to contain the situation at the badly damaged nuclear facility.

 

A COLUMBAN missionary has witnessed a massive contamination clean-up in the Japanese region surrounding Fukushima, where a 2011 earthquake and tsunami triggered a nuclear power plant meltdown.

Fr Paul McCartin, recently visited the Fukushima region, six years after the nuclear disaster, and ahead of a government evacuation order being lifted at the end of this month, which will allow people to return home.

Arriving by bullet train at the town of Kouriyama, 60km west of Fukushima Number One Nuclear Power Plant, Fr McCartin said the first surprise was the large radiation monitor in front of the station.

Over the next three days I saw similar monitors in cities, beside country roads and along expressways,” Fr McCartin, the Columban Justice, Peace and the Integrity of Creation co-ordinator in Japan, said.

He has worked in Japan since 1979 and visited the Fukushima last September.

I had taken face masks but our guides gave us better ones,” he said.

We were told to make sure we washed our hands and around our mouths before eating.

I was given a small radiation monitor to wear around my neck.

Over the two-and-a-half days I was exposed to 8.1 micro Sieverts, an ‘acceptable’ amount.”

The Sievert is a measure of the health effect of low levels of ionising radiation on the human body.

As Fr McCartin drove through the Fukushima countryside, he found houses barricaded, roads closed and warnings from officials amidst a massive clean-up.

I was restricted. There were roadblocks with security personnel,” he said.

I was advised not to hike in Fukushima as there is a lot of radiation in the mountains, especially at the base of mountains as rain washes it down.

Buildings and roads are being washed down, and contaminated soil and vegetation being removed.”

He said topsoil to a depth of five centimetres was being removed and replaced with soil from unaffected areas.

There are large collections of industrial waste bags all over the place. There must be hundreds of thousands, if not millions,” he said.

At the end of March, Japan is set to lift evacuation orders for parts of Namie, located 4km from the wrecked Fukushima Daiichi nuclear plant, as well as three other towns.

More than half of Namie’s former 21,500 residents have decided not to return.

Namie, and other nearby centres are now ghost towns, dilapidated, and for many, they conjure horrific memories.

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Tsunami damage: Facilities near the seawater heat exchanger building at Tokyo Electric Power Company’s Fukushima Daini nuclear power plant Unit 3 reactor on April 2, 2011, days after an earthquake and tsunami hit the area in north-east Japan.

A government survey showed last year, there were lingering concerns over radiation and the safety of the nuclear plant, which is being decommissioned.

Beyond radiation risks, an unexpected nuisance looms – hundreds of wild boars have descended from surrounding hills and forests into the deserted towns.

The creatures have roamed across the radioactive contaminated region.

In Namie, wild boars occupy the empty streets and overgrown backyards foraging for food.

In the nearby town of Tomioka, local hunters have captured an estimated 300 boars.

Following his visit last September, Fr McCartin is concerned about the spread of contaminated material.

Low-level waste is being recycled,” he said.

Highly contaminated waste is being burned.

So far only one per cent of high-level waste has been burned.

More incinerators are being constructed.

Contaminated waste is being used in the wall being built along the shore to prevent another tsunami hitting the area.

In fact, there is so much radioactively contaminated waste that local facilities can’t handle it, so ‘low-level waste’ is being transported to many distant places for disposal.

Contaminated fishing gear and nets are being disposed of in the town where I live.

In this way, radiation is being spread to many parts of the country.

It would seem to make sense to keep it where it is and avoid unnecessarily contaminating the rest of the country.”

Fr McCartin said the Japanese media was muzzled from challenging the government on Fukushima and the hazards of nuclear power.

The efforts of individual journalists reporting on the issue were often dismissed.

A Catholic in Yokohama told me last year that after his daughter wrote a piece on Fukushima for the newspaper she works for, her boss told her, ‘No more on Fukushima’,” he said.

The government has threatened to shut down any media organisation that publishes something the government doesn’t like.

In the last year or so three forthright and prominent media personalities have been sacked or not had their contracts renewed.”

Fr McCartin said he supported a call by Japanese Catholic bishops to abandon the nuclear power industry.

I believe that if the government transferred a small fraction of the trillions of dollars it throws at the nuclear industry to the renewable energy industry, the country would be awash in safe energy in a very short time,” he said.

http://catholicleader.com.au/news/columban-missionary-backs-bishops-against-nuclear-industry-after-harrowing-visit-to-fukushima-clean-up

March 28, 2017 Posted by | Fukushima 2017 | , , , | 2 Comments

The Robot Probe Cannot Confirm Where is the Melted Fuel of Unit 1

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Tokyo Electric Power Company announced on February 23 that it had completed a robot probe survey lasting five days in the reactor containment vessel of Fukushima Daiichi nuclear power plant Unit 1.

Its goal was to confirm the whereabout of the melted nuclear fuel, but it was blocked by piping and could not put the camera in athe place where nuclear fuel could be seen.

Information necessary for taking out the nuclear fuel to decommission the reactor remains inadequate, and some voices began to question the robot conducted investigation method.

During the 5-day survey, there was also a point where the measuring instrument with an camera and a radiation dosimeter integrated together was hung up in a range from 0 to 3 meters from the bottom of the containment vessel, pipes and debris blocking its path in many points. The radiation dose in the water is from 3.0 to 11 Sv. Per hour. It was not possible to directly check the melted nuclear fuel.

TEPCO and the country are facing the decommissioning of a furnace …

http://www.asahi.com/articles/photo/AS20170323005483.html

March 24, 2017 Posted by | Fukushima 2017 | , , , , | Leave a comment

Deadly nuclear radiation levels detected in Fukushima

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Extremely high radiation levels were detected using cameras and robots in tainted water inside a reactor containment vessel at the Fukushima No. 1 nuclear power plant, Japan Times reported Tuesday, citing Tokyo Electric Power Company Holdings Inc. (Tepco).

The latest readings, taken six years after the Fukushima nuclear meltdown, showed 11 sieverts per hour, according to Japan Times. It is the highest radiation level detected in water inside the containment vessel and is extremely dangerous. Sievert is a unit measurement for a dose of radiation. One sievert is enough to cause illness if absorbed all at once, and 8 sieverts will result in death despite treatment, according to PBS who relied on data from multiple sources including United States Nuclear Regulatory Commission and MIT’s Nuclear Science and Engineering department.

Following a major earthquake on March 11, 2011, a 15-metre tsunami disabled the power supply and cooling of three Fukushima reactors, causing a nuclear accident. Tepco, who operated the plant and has been tasked with cleaning up the worst nuclear incident, since the 1986 Chernobyl disaster in the former Soviet Union, has been some problems of late in its cleanup operation.

Recently, an exploratory robot malfunctioned and died after being sent inside reactor 2, in mid-February, due to exposure to “unimaginable” levels of radiation, close to 650 sieverts per hour. The previous highest recorded level was 73 sieverts per hour. Following the incident, Naohiro Masuda, president of Tepco’s Fukushima Daiichi Decommissioning project, told reporters the company had to rethink its methods in order to examine and extract the hazardous material stuck in the plant’s second reactor.

We should think out of the box so we can examine the bottom of the core and how melted fuel debris spread out,” Masuda said, according to the Japan Times.

Tepco has been attempting to locate melted fuel which leaked from the reactor’s pressure vessel and is believed to have settled at the bottom of the containment vessel that holds the contaminated water. So far, no such debris has been found, and Tepco decided to extend the survey by one day through Wednesday.

A robot sent by the company on March 20 reached the bottom but was unable to locate the melted fuel due to some pipes that blocked its view.  But it was able to take pictures of what appeared to be sand piling up near the pipes. The radiation readings near them were 6.3 sieverts per hour.

Judging from the radiation level, there is a high possibility that what is piling up on the pipes is not nuclear fuel,” a Tepco official said, according to the Asahi Shimbun

Cleaning up the plant may take an estimated 40 years and cost an estimated 21.5 trillion yen ($189 billion), according to the Guardian.

https://www.rawstory.com/2017/03/deadly-nuclear-radiation-levels-detected-in-fukushima/

March 23, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Lethal radiation levels but no melted fuel found in Fukushima reactor water

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The Unit 2 reactor building at Tokyo Electric Power Co.’s Fukushima Daiichi nuclear power plant.

The level of radiation was measured by a special robot on Sunday at a point about 30cm (one foot) from the bottom of the containment vessel of Reactor 1, the Japan Times reported on Tuesday.

The current radiation level is 11 sieverts per hour, the highest detected in water inside the containment vessel. A person exposed to this amount of radiation would likely die in about 40 minutes, the Japan Times reports.

Sunday’s probe also revealed sandy substances building up at the bottom of the vessel. Tokyo Electric Power Company Holdings (TEPCO) officials, however, dismissed the idea that it might be melted nuclear fuel.

Experts have been looking for the melted fuel, which they believe has been accumulating in tainted water.

In March 2011, a 9.1 earthquake and the 15-meter tsunami that followed disabled the cooling system of Fukushima’s three reactors, causing the worst nuclear incident since the 1986 Chernobyl incident in Ukraine.

TEPCO, which operates the crippled power plant, has been obliged to deal with the consequences of the incident.

In February, a robot sent to explore Reactor 2 broke down because of the “unimaginable” levels of radiation, close to 650 sieverts per hour. This was the first time a robot entered this reactor since the plant’s meltdown in 2011.

Previously, the highest radiation level was recorded one year after the disaster and went up to 73 sieverts per hour.

TEPCO has promised extract the hazardous material stuck in the plant’s second reactor, its president Naohiro Masuda said, according to the Japan Times.

In December, TEPCO nearly doubled the estimated cost for the Fukushima clean-up to $188 billion.

A zone of more than 300 square miles around the plant is currently uninhabitable due to the continuing radiation.

https://www.rt.com/news/381879-fukushima-reactor-radiation-lethal/

 

March 23, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Robots Go Into The Fukushima Nuclear Plant Site, But Don’t Come Out

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In 2011, a 9.0 magnitude earthquake off the coast of Japan caused a massive tsunami, which in turn led to the meltdown of three nuclear reactors at the Fukushima Nuclear Power Plant in Fukushima, Japan. As a result, the site went on to release radioactive material for the next three days, becoming only the second such disaster in history–after Chernobyl in 1986–to be classified a Level 7 event on the Nuclear Event Scale.

So perhaps it should come as no surprise that, just past the tragedy’s six year anniversary, Tokyo Electric Power Co. (Tepco) has made little progress in cleaning up the disaster site. 

While Tepco has spent much of its time containing radiation and attempting to minimize groundwater contamination, its current mission is to locate and retrieve 600 tons of melted nuclear fuel rods lost somewhere in the radioactive wreckage. As the levels of radiation are still too high for human exposure, this task has fallen to robots. Yet so far, even the robots have failed repeatedly to locate the melted fuel rods; instead, they are dying within the reactors they were sent in to survey. 

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The latest device to meet its end was a scorpion-shaped robot built by Toshiba, which entered one of the reactors last month but stalled just 10 feet short of its target in a matter of hours. While it was ultimately undone by the failure of its left roller-belt, the robot was exposed to far higher than expected levels of radiation, which likely interfered with its electronics and prevented it from sending photos that could have shed some light on the location of the melted fuel rods.

Despite being manufactured using special radiation-hardened materials to protect its circuits from exposure, the levels of radiation it encountered within the reactor far exceeded the robot’s tolerance. Two prior robot missions had to be aborted as well after one got stuck and another failed to locate any melted fuel for several days.

Despite the setbacks, Tepco believes it is getting closer to locating the melted fuel, and hopes to begin removal by 2021, but admits it is a long-term project. The Japanese government estimates that it will take upwards of 40 years and $70.6 billion to complete the clean-up.

According to MIT nuclear science professor Jacopo Buongiorno, “the roadmap for removing the fuel is going to be long, 2020 and beyond. The re-solidified fuel is likely stuck to the vessel wall and vessel internal structures. So the debris have to be cut, scooped, put into a sealed and shielded container and then extracted from the containment vessel. All done by robots.”

But that begs the question: what robots? 

None of those they’ve sent in so far has done the trick. What if the technology required to create the chips and robots that are radiation-hardened yet not too weighed down by protective shielding hasn’t even been invented yet? Bloomberg reports that Toshiba intends to send a new robot into Reactor 3 next year at this time to continue the search, but it is still in the development phase, and Toshiba has not yet made design details public.

The good news is that with a 40 year time horizon, the likelihood of technology catching up with Tepco’s needs is fairly good. But when will the site be clean enough so that more people may return to their homes? In the meantime, radioactive boars have been making themselves quite at home there.

http://secondnexus.com/technology-and-innovation/fukushima-robots-keep-dying/

March 21, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

The illusion of normality at Fukushima

Six years after it suffered a nuclear meltdown, Fukushima appears to have returned to a semblance of normalcy. But there is still a long way to go in terms of cleaning up the site. Martin Fritz reports.

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A filter mask covering the mouth and nose, a headscarf, a helmet, gloves and two layers of socks – they constitute the protective gear that must be worn by any ordinary visitor to the Fukushima nuclear power station. 

Only a few workers now have to wear face masks and hazmat suits, since most of the ground at the site has been sealed with concrete.

“The radiation is now as low as in the Tokyo’s Ginza shopping district,” Tokyo Electric Power Co. (TEPCO) manager Yuichi Okamura assured a group of journalists during their recent visit to the plant.

But the illusion of normality evaporates as soon as the visitors get off their bus and stand within sight of the reactors, with dosimeters indicating radiation levels of around 160 to 170 microsieverts per hour – nearly 2,000 times above what is considered safe.

“We cannot stay here for long,” warns Okamura.

On the surface, it appears that much has changed in Fukushima since the disaster struck six years ago. The clean-up work has evidently made progress.

But the sight of skeletal steel frames, torn walls and broken pipes immediately reminds one of the 17-meter-high tsunami which flooded the facility six years ago and brought its reactors to a complete standstill.

It’s expected to take 30 to 40 years to completely clean up the Fukushima Daiichi plant, which was hit by the world’s worst nuclear disaster since Chernobyl following a magnitude-9 earthquake and the subsequent tsunami. The operation is likely to carry a hefty price tag, with Japanese officials recently estimating it to cost around $189 billion in total.

Today, with 6,000 workers employed, the nuclear power plant is Japan’s largest and most expensive construction site – and it will remain so for decades. “We’re struggling with four problems,” says TEPCO manager Okamura: “Reducing the radiation at the site, stopping the influx of groundwater, retrieving the spent fuel rods and removing the molten nuclear fuel.”

Black lumps in the reactor containment

Progress in these areas, however, is slow. For instance, workers are erecting scaffolding around the collapsed roof of reactor No 1, but it will likely take four more years for the debris there to be cleared away. Only then can the almost 400 old fuel rods be retrieved from the reactor’s holding basin.

In the adjacent reactor No 2, the blue exterior still remains intact. Workers in hazmat suits can be seen walking on a new metal platform halfway up the reactor building.  But behind the wall lies a nuclear nightmare. A robot sent into the reactor in January found highly dangerous black lumps of leaked fuel on a platform in the outer reactor containment.

“There is now fatally high radiation in that part,” says Okamura.

The engineer quickly turns to reactor No 3, where the progress is more obvious. A hydrogen explosion had turned the reactor’s roof into a tangle of bent metal. It took years of work to dismantle this steel scrap and remove the rubble. “Now we’re building a new roof with an integrated hoisting crane,” says Okamura proudly.

“From next year, we would finally be able to close in on the nearly 600 burnt fuel rods,” he noted. But unlike in reactor No 4, the clean-up must be undertaken remotely as the radiation is so strong that people can only stay there for a few minutes. As a result, the construction of the lifting device has already been delayed by several years. 

Unclear conditions

The situation at the reactors raises doubts about the optimism shared by Japanese officials with regard to the orderly decommissioning of the plant. At the next stop, Okamura shows the control center of the underground ice wall that was built to prevent groundwater from leaking into the reactor basements and mixing with radioactive coolant water.

Since its construction, it has managed to reduce the amount of groundwater flowing into the reactor basements. But five sections of the wall have had to be kept open to prevent water inside the reactor basements from rising and flowing out too rapidly.

Despite all these adversities, the Japanese government and TEPCO are planning to decide as early as this summer how to remove the molten nuclear fuel from the reactors.

Even Shunji Uchida, the Fukushima Daiichi plant manager, couldn’t hide his skepticism from the visiting journalists. “Robots and cameras have already provided us with valuable pictures,” says Uchida, adding: “But it is still unclear what is really going on inside.”

http://www.dw.com/en/the-illusion-of-normality-at-fukushima/a-37885120

March 15, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Six years on, Fukushima rests its hopes on fearless robots

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As the struggle continues to bring the six-year-old triple nuclear meltdown at Fukushima Daiichi under control, robots are providing a first, albeit expendable, line of assault.

The robots are on a high-tech suicide mission into the nooks and crannies beneath the stricken plant’s three melted-down reactor cores to discover and map an estimated yet elusive 600 tons of molten nuclear fuel.

Radiation levels in these corridors can reach up to 650 sieverts and hour, higher by nine times than the previous highs measured at the plant, which plateaued at a mere 73 sieverts in 2012.

A whole human body dose of 10 sieverts is enough to cause immediate illness and death within a few weeks at most, 650 within a minute.

Levels like those recently found in the snarls and wreckage beneath Fukushima’s reactor No 2, where radiation is more concentrated because, unlike reactor No 1 and 3, it didn’t suffer a hydrogen explosion, are lethal not just to humans but, as it turns out, to robots as well.

The most recent robot that Tokyo Electric Power Co., the owner of the Fukushima plant, sent into the breach of reactor No 2 died in less than a day. The two before that got stuck in narrow passages and were given up for dead, and a third was abandoned after it spent six days searching for the reactor’s melted fuel. Yet one more robot was sacrificed in action while trying to locate one of its lost compatriots.

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Scientists are trying to develop robots better suited to the high radiation intensity. Yet they say the metallic body count is producing results by giving technicians a view of where the melted down fuel is located and helping them produce 3-D models of what it looks like.

The hope is that robots will be doing the heavy lifting when it comes time to dig out the fuel on a decommissioning job now expected to last another 30 to 40 years at a new cost of $189 billion – nearly double estimates released three years ago.

But on behalf of the 6,000 human workers at the site: Better the robots than them.

Six years ago, on March 11, 2011 a 9.0 magnitude earthquake 72 kilometers out to sea slammed a 39-meter tsunami into the Fukushima Daiichi nuclear power plant, causing a triple meltdown. In the days that followed, uranium fuel melted down in three of the six reactors. Explosions in three of the reactor buildings belched radioactive iodine, cesium and other fission by-products into the environment.

In the immediate aftermath, Japan shut down its 42 remaining nuclear reactors. Up to 160,000 people who lived within a 20-kilometer radius of the plant were forced to evacuate homes where they had lived for generations with their families in agricultural Fukushima.

Six years later, the lemming-like march of robots into the still chaotic cleanup of the plant has become a hopeful metaphor for technology accomplishing what is beyond humanity’s grasp, and their deaths are getting a lot of attention.

Tepco is still hewing to its vow of securing the plant by 2050 to 2060, and says that for the first time since the accident it has succeeded in reeling in the threat the wrecked plant poses to the surrounding area. A visual example of that, noted by reporters who took their annual tour of the plant, is that the thousands of workers on site can now work in ordinary work clothes and surgical masks rather than protective gear. And there are fewer workers to count. Where 8,000 were working at the site last year, 2000 fewer are needed now.

Damaged reactor buildings have been reinforced and 1,300 precariously perched spent fuel assemblies at reactor No. 4 that were a potential disaster all their own have been safely removed. The ground has also been covered with a special coating to prevent rainwater from added to Tepco’s water management struggles.

The company’s projection that it will finish the cleanup in the next four decades, however, is viewed skeptically by Japan’s Nuclear Regulatory Authority, which recently told the Guardian newspaper that the effort was still groping in the dark. And many are suspicious that the Tepco’s optimism is just public relations to assure the international community ahead of the 2020 Tokyo Olympics.

Can you go home again?

Another looming nightmare for many thousands of people is the prospect of loosing government financial support if they don’t move back to villages and towns they evacuated, which many environmental groups say are still highly contaminated.

The evacuation orders enacted by Prime Minister Shinzo Abe’s government after the disaster will be stripped later this month, forcing the evacuees back to live in areas that where in the direct path of the disaster.

Abe’s government says it’s safe for people to return to areas where radiation is 20 millisieverts per year or lower. The globally-accepted limit for radiation absorption is 1 millisievert per year, though the IAEA says anything up to 20 millisieverts per year poses no immediate danger to humans. That has been disputed by numerous studies.

Water hazards

At the plant, contaminated water still poses one of the biggest threats to the wider environment. Nearly one million tons of it stored across 1,000 tanks that were collected after the reactors were blasted with seawater to cool them down. More water has poured in as technicians continue to circulate it through the destroyed reactors to keep them cool.

Leaks from these tanks have often contaminated groundwater, and Tepco has struggled to divert the radioactive deluge from spilling into the Pacific Ocean with an underground wall of frozen soil.

The wall looks a bit like the piping behind a refrigerator and sinks 30 meters into the ground. Over the last year, Tepco pumped water into it to begin the freezing process. But some reports say the wall is having less success in another of its tasks – holding back groundwater from leaking into the basements of reactor buildings, which creates yet more contaminated water.

At their six-year anniversary briefing to reporters, Tepco admitted it was conflicted over what to do with the sea it has amassed. The company says it will be able to cleanse much of the water of cesium, strontium and 50 other radionuclides. But they’re still stumped by how to get rid of tritium, a radioactive isotope of hydrogen, which is still in that water.

Tepco is studying two options. One is to simply dilute the water further and dump it into the sea, as tritium naturally occurs in water in microscopic quantities. They’re also considering evaporating all 960,000 tons of it to release the tritium into the atmosphere.

The company says the final decision will be subject to a public hearing process. Should dumping water into the sea – as has happened numerous times before – still be among the considerations, it would doubtless meet the fierce opposition of fishermen, who have struggled with contaminated seawater since the accident.

Robots’ maze hunt

But by far the most technically involved struggle is finding and removing the fuel that melted down in reactor Nos 1, 2 and 3. And for that, enter the robots, each of which has to be shaped to its task.

At reactor No. 2, where the robot crews have been doing most of their work, it’s not yet known if the fuel melted into or through the reactor vessel’s concrete floor. Determining where that fuel is, and how radioactive it is, dictates how the robots will be designed.

And that’s just for this reactor. At reactor Nos 1 and 3, robots will have to be further customized to handle the specifics of each location. With explorations underway at reactor No 2, Tepco says it expects more robots to march into the other reactors by this summer.

At that point, they say, they will set policy on how the melted fuel will be removed, a process that isn’t expect to begin until 2021.

Designing and building what Tepco refers to as “single function robots” takes as long as two years, and that’s only when you know what you are making the robots for.

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One of the robots currently on the drawing board, for instance, would be able to leap over debris. Another that Hitachi is reportedly designing will resemble a snake so it can lower cameras through a grating in reactor No 1 to scope out and photograph melted down fuel there. That will be third Hitachi robot of that design.

Another robot designed by Toshiba, which was widely eulogized throughout the media, was designed to the anatomy of a scorpion. It died at the end of February just shy of a grating through which it might have got a peek of melted down fuel in reactor No 2.

Newer robot designs, according to a Tepco spokesman who talked with Bloomberg, are incorporating fewer wires and circuits and are built with harder parts than their earlier cousins.

But even the robots that peter out in the radiation are providing valuable clues: Toshiba’s scorpion robot sent the first grainy images from within reactor No 2 of a black residue that could actually be the spent fuel it was sent in to find.

Whether the fuel is in discrete piles or has melted to the walls of its containment vessels will present yet new challenges. Tepco and other scientists expect it’s a bit of both. Fuel that oozed and then re-melted inside the core or adhered to other reactor structures will have to be cut out, shoveled up and placed in shielded containers before it can be removed. This will be the robots’ job.

Earning the trust of a suspicious public

Six years of work is doing little to dent public suspicion of nuclear power in a country that previously relied on its 54 reactors to supply 30 percent of its power.

Tepco – which last year was shown to have delayed reporting the initial meltdowns after the catastrophe by 88 days, thus jeopardizing tens of thousands of lives – has a long way to got before it regains trust. Numerous other independent scientists are said by Japanese activists to be massaging data to make the situation look better than it is.

The mistrust is visible both in how slowly Japan is allowing its nuclear reactors go back online, and by the trickle of people who are willing to return to homes in the Fukushima Prefecture from which they were evacuated.

Japan’s reactors, all of which were shut down in the wake of the disaster, must pass the world’s most stringent stress tests before utilities can consider switching them back on. But even after they’re cleared technically, the people living near the plants have to want them back – and not many do.

As of this year, only three nuclear reactors have been switched on since 2011. Two others at the Genkai nuclear power plant on Japan’s Kyushu Island, were green lighted by a local mayor, but now must be approved by seven other surrounding municipalities.

In the most recently available national polls, taken last year on the fifth anniversary of the disaster, 70 percent of the population opposes the reactor restarts.

Among the more than 160,000 people reckoning with the dilemma of moving back to areas affected by radiation, 60 percent report feeling physical, psychological, financial and emotional stress as a result of the disaster, Japan’s NHK television reported. Up to 72,500 of these people still live in government supplied temporary housing.

In Naime, only 4 kilometers northwest of the plant, more than half of the resident have elected not to return, according to government surveys. Levels there recently hover around 0.07 microsieverts per hour, but down the road in Tomioka, they spike to 1.48 microsieverts an hour, more than 30 times levels in downtown Tokyo, showing there are still lingering radiation hotspots.

One group that is not afraid of populating the ghost-towns surrounding the plant are, according to reports, wild boar. The animals, which have grown up without humans around have reportedly grown fearless.

Tamotsu Baba, the mayor of Naime who is pushing for resettlement by the end of the month, told Reuters the boars pose make the town even less hospitable than the threat of radiation.

http://bellona.org/news/nuclear-issues/2017-03-six-years-on-fukushima-rests-its-hopes-on-fearless-robots

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

Proud workers at Fukushima No. 1 nuke plant risk deadly radiation danger

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Workers examine the inside of the No. 2 reactor containment vessel at the Fukushima No. 1 Nuclear Power Plant on Jan. 30, 2017.

Tokyo Electric Power Co. (TEPCO) has failed to grasp the entire picture of melted fuel possibly accumulating inside the container vessel of the No. 2 reactor at the Fukushima No. 1 Nuclear Power Plant. The radiation levels inside the vessel are extremely high, to the extent a human could be killed in less than a minute, and even a robot designed to conduct a probe inside went down quckly.
The Mainichi Shimbun visited the disaster-stricken plant late last year ahead of the sixth anniversary of the nuclear meltdowns at the facility in March.

On the early morning of Dec. 24, 2016, a group of 26 workers assembled at a building housing the No. 2 reactor when it was still dark outside. The workers were from heavy machinery giant IHI Corp. and other companies engaged in disaster recovery work. On top of their protective Tyvek suits, they were wearing special protective ponchos. They also had four-layer gloves on, with plastic tape wrapped around their wrists. The outfit made them sweat though it was the middle of winter.

In order for TEPCO to move ahead with decommissioning work on the No. 1 through No. 3 reactors at the plant, the utility needs to find out how much melted nuclear fuel lies inside the facilities, and where, in the aftermath of the meltdown of 1,496 fuel rods. The 26 workers were tasked with drilling a hole measuring 11.5 centimeters in diameter in the No. 2 reactor’s container vessel to open the way for the probe robot, using a remotely controlled machine.

Ryosuke Ishida, 28, an employee of a related company in Hokkaido, was in charge of removing the machinery that was used in the drilling work. In order to ward off the severely high radiation, he was wearing a lead jacket weighing 10 kilograms on top of his already tightly sealed protective gear. Each worker was allowed only five minutes for their task to keep their radiation exposure doses to no more than 3 millisieverts a day. The dosimeters they were carrying with them were set to beep when the radiation level reached 1.5 to 2 millisieverts, with an additional alarm set to go off when radiation doses hit every one-fifth of those levels.

Ishida’s dosimeter beeped just under a minute after he stepped inside the No. 2 reactor building. “Is it beeping already?” he thought to himself. The radiation levels vary greatly depending on where one stands inside the facility. Although Ishida had got a firm grasp on where the hot spots were during pre-training, he found himself “inadvertently standing on highly radioactive spots as I was focused on work.”

While trying to calm himself down, Ishida sped up his manual work. Alas, a machine component for turning a bolt fell off and rolled on the floor. “Damn, I’m running out of time,” he thought. His full face mask went all white as he sweated physically and emotionally, blocking his view. By the time he finished picking up the fallen component and wrapped up his work, he was sweating all over his body.

“It’s a battle against radiation at the site,” Ishida recalled. He added, though, “Because nobody else wants to do the job, I find it all the more worthwhile and take pride in it.”

http://mainichi.jp/english/articles/20170227/p2a/00m/0na/007000c

February 28, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Fukushima: No End in Sight

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KGO Radio: Host Pat Thurston recently interviewed Arnie Gundersen, chief engineer for Fairewinds Energy Education on KGO radio to discuss the latest challenging news from Japan about the Fukushima Daiichi atomic power reactor including the high levels of radiation emanating from the reactors, all the failed robotic expeditions, where we should go from here, as well as how ongoing radioactive releases from the Fukushima Daiichi site may be impacting the west coast of the United States.

 

BBC Newsday: BBC Radio interviewed nuclear engineer Arnie Gundersen to discuss TEPCO’s attempts to send a special robot into Fukushima Daiichi Reactor #2 in Japan to investigate the obstacles in the way of TEPCO’s progress determining the location and condition of the atomic fuel. Unfortunately even this specially designed robot failed in its attempt to clear the path for additional investigations as the nuclear radioactivity was so high, it shut down the robots before they could complete their mission.

Listen Here

 

Enviro News: The astronomical radiation readings at Fukushima Daiichi Reactor #2 of 530 Sv/hr complicate the already complex task of decommissioning the plant. These levels are so radioactive that a human would be dead within a minute of exposure and specially designed robots can only survive for about 2 hours. Fairewinds chief engineer Arnie Gundersen says that the best solution would be to entomb the reactors, similar to the sarcophagus entombing Chernobyl, for at least 100-years, otherwise the radiation level that workers would be exposed to is simply too dangerous.
Read the whole article here

 

 

Are the meltdowns at Fukushima Daiichi over? The answer is no. Made all the more prevalent a year out from it’s initial release by the recent robotic expeditions into Reactor #2 which gave us a clearer picture on just how deadly the radiation levels are, watch Chief Engineer and nuclear expert Arnie Gundersen inform viewers on what’s going on at the Japanese nuclear meltdown site, Fukushima Daiichi. As the Japanese government and utility owner Tokyo Electric Power Company push for the quick decommissioning and dismantling of this man-made disaster, the press and scientists need to ask, “Why is the Ukrainian government waiting at least 100 years to attempt to decommission Chernobyl, while the Japanese Government and TEPCO claim that Fukushima Daiichi will be decommissioned and dismantled during the next 30 years?”
Like so many big government + big business controversies, the answer has nothing to do with science, and everything to do with politics and money. To understand Fukushima Daiichi, you need to follow the money.

http://www.fairewinds.org/newsletter-archive//no-end-in-sight

February 23, 2017 Posted by | Fukushima 2017 | , , , , | Leave a comment

Fukushima nuclear disaster evacuees ‘pressured’ to return to contaminated homes, says Greenpeace

Even though radiation levels in a village near the site of the Fukushima nuclear disaster still exceed international guidelines, its evacuated residents are being coerced to return, according to a Greenpeace report.

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Residents from the Japanese ghost village of Iitate will be allowed to return to their former homes at the end of March – the first time since they were forced to flee the Fukushima nuclear disaster in 2011. That’s the date the Japanese government has set to lift evacuation orders.

But according to environmental organization Greenpeace, it’s uncertain whether many will want to. Greenpeace says tests it has carried out on homes in Iitate show that despite decontamination, radiation levels are still dangerously high – but that’s not stopping the Japanese governmenment from pressuring evacuees from returning, under threat of losing financial support.

Those who refuse to go back to their former homes, and are dependent on the Japanese government’s financial help, are faced with a dilemma. After a year from when an area is declared safe again to live in, evacuated residents will see their compensation payments terminated by the government.

Radiation ‘comparable with Chernobyl’

The nuclear disaster led to more than 160,000 people being evacuated and displaced from their homes. Of these, many tens of thousands are still living in temporary accommodation six years on.

The village of Iitate, lying northwest of the destroyed reactors at Fukushima Daiichi power plantand from which 6,000 citizens had to be evacuated, was one of the most heavily contaminated following the nuclear disaster.

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Government employees monitor radiation at a day-care center in Iitate in 2011

Around 75 per cent of Iitate is mountainous forest, an integral part of residents’ lives before the nuclear accident.

But according to Greenpeace’s report, published on Tuesday, radiation levels in these woods are “comparable to the current levels within the Chernobyl 30km exclusion zone – an area that more than 30 years after the accident remains formally closed to habitation.”

Put another way, Greenpeace said that in 2017, there clearly remains a radiological emergency within Iitate – defining emergency thus: “If these radiation levels were measured in a nuclear facility, not Iitate, prompt action would be required by the authorities to mitigate serious adverse consequences for human health and safety, property or the environment.”

The environmental organization says decontamination efforts have primarily focused on the areas immediately around peoples’ homes, in agricultural fields and in 20-meter strips along public roads.

But these efforts ended up generating millions of tons of nuclear waste – these now lie at thousands of locations across the prefecture, but they haven’t reduced the level of radiation in Iitate “to levels that are safe,” says Greenpeace.

‘Normalizing’ nuclear disaster?

The organization has accused the Japanese government of trying “to normalize a nuclear disaster, creating the myth that just years after the widespread radioactive contamination caused by the nuclear accident of 11 March 2011, people’s lives and communities can be restored and reclaimed.

“By doing so, it hopes, over time, to overcome public resistance to nuclear power.”

Greenpeace also lambasted the government for leaving unanswered what it calls a critical question for those trying to decide whether to return or not: what radiation dose will they be subjected to, not just in one year but over decades or a lifetime?

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Greenpeace says Japan’s government wants to restore public confidence in nuclear power at the cost of harming residents

“Until now the Japanese government has exclusively focused on annual radiation exposure and not the potential radiation dose rates returning citizens could potentially face over their entire lifetime,” says Greenpeace.

Greenpeace, which has been monitoring Iitate since 2011, carried out its latest survey in November 2016

It found that the average radiation dose range for Iitate beginning from March 2017 over a 70-year lifetime was between 39 millisieverts (mSv) and 183mSv – and that’s not including natural radiation exposure expected over a lifetime, or the exposure received in the days, weeks and months following the March 2011 nuclear disaster.

That exceeds yearly guidelines set by the International Commission on Radiological Protection (ICRP) when added up over a 70-year period – it puts the maximum recommended radiation exposure at 1mSv annually.

Greenpeace says: “The highly complex radiological emergency situation in Iitate, and with a high degree of uncertainty and unknown risks, means that there is no return to normal in Iitate, Fukushima prefecture.”

It has called on the Japanese government to cease its return policy, and to provide full financial support to evacuees, and “allow citizens to decide whether to return or relocate free from duress and financial coercion.”

According to Greenpeace, “for the more than 6,000 citizens of Iitate, this is a time of uncertainty and anxiety.”

Heinz Smital, nuclear physicist and radiation expert at Greenpeace Germany, and part of the team taking measurements at Iitate, told DW the residents were faced with a very difficult situation.

“If you decide to live elsewhere [and not return to Iitate], then you don’t have money, you’re sometimes not welcomed in another area so you are forced to leave, because people say, ‘you’re not going back but you could go back,'” he said. “But for people who go back, they have contaminated land, so how can they use the fields for agriculture?”

He urged the Japanese government to more involve those affected in the decision-making process and not try to give an impression that things are “going back to normal.”

“It’s a violation of human rights to force people into such a situation because they haven’t done anything wrong, it’s the operator of the power plant responsible for the damage it caused,” said Smital.

“It’s very clear that there’s very serious damage to the property and the lifestyle of the people but the government doesn’t care about this.”

http://www.dw.com/en/fukushima-nuclear-disaster-evacuees-pressured-to-return-to-contaminated-homes-says-greenpeace/a-37639353

February 23, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

FOCUS: Failed Survey Complicates N-Fuel Removal at Fukushima Plant

It looks like its too radioactive for robots to survive. I wonder how they will do this work now?

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Tokyo, Feb. 20 (Jiji Press)–A failed robot survey of melted nuclear fuel that has dropped through the bottom of a damaged reactor pressure chamber at the Fukushima No. 1 nuclear plant complicates the formulation of a policy in the summer for taking out the fuel debris.
The removal of the molten nuclear fuel is regarded as the most demanding challenge in the decommissioning of the disaster-stricken plant’s reactors, said to take 30 to 40 years.
Tokyo Electric Power Company Holdings Co. <9501>, the manager of the plant in Fukushima Prefecture, northeastern Japan, is discussing the drawing up of a broad policy outline before conducting an additional survey to work out a detailed plan for the nuclear fuel removal, company officials said.
TEPCO’s initial plan called for a self-propelled survey robot, dubbed scorpion, to enter the No. 2 reactor’s containment vessel and travel on a 7.2-meter rail to reach a metal grating directly beneath the reactor’s damaged pressure chamber. The robot would have surveyed the extent of damage to the chamber, while locating melted nuclear fuel that is believed to have dropped through the metal grating to the bottom of the containment vessel and shooting the fuel’s images.
The No. 2 reactor is one of the three units that suffered meltdown due to the failure of their cooling systems caused by the March 2011 earthquake and tsunami.

http://jen.jiji.com/jc/eng?g=eco&k=2017022000007

February 21, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Melted Nuclear Fuel Search Proceeds One Dead Robot at a Time

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The latest robot seeking to find the 600 tons of nuclear fuel and debris that melted down six year ago in Japan’s wrecked Fukushima Dai-Ichi power plant met its end in less than a day.

The scorpion-shaped machine, built by Toshiba Corp., entered the No. 2 reactor core Thursday and stopped 3 meters (9.8 feet) short of a grate that would have provided a view of where fuel residue is suspected to have gathered. Two previous robots aborted similar missions after one got stuck in a gap and another was abandoned after finding no fuel in six days.

After spending most of the time since the 2011 disaster containing radiation and limiting ground water contamination, scientists still don’t have all the information they need for a cleanup that the Japanese government estimates will take four decades and cost 8 trillion yen ($70.6 billion). It’s not yet known if the fuel melted into or through the containment vessel’s concrete floor, and determining the fuel’s radioactivity and location is crucial to inventing the technology needed to remove it. 

The roadmap for removing the fuel is going to be long, 2020 and beyond,” Jacopo Buongiorno, a professor of nuclear science and engineering at the Massachusetts Institute of Technology, said in an e-mail. “The re-solidified fuel is likely stuck to the vessel wall and vessel internal structures. So the debris have to be cut, scooped, put into a sealed and shielded container and then extracted from the containment vessel. All done by robots.”

Read more: Robots are being utilized to clean up U.K.’s nuclear waste

To enter a primary containment vessel, which measures about 20 meters at its widest, more than 30 meters tall and is encased in meters of concrete, outside air pressure is increased to keep radiation from escaping and a sealed hole is opened that the robot passes through. Three reactors at the plant suffered meltdowns, and each poses different challenges and requires a custom approach for locating and removing the fuel, said Tatsuhiro Yamagishi, Tokyo Electric Power Co. Holdings Inc. spokesman.

The machines are built with specially hardened parts and minimal electronic circuitry so that they can withstand radiation, if only for a few hours at a time. Thursday’s mission ended after the robot’s left roller-belt failed, according to Tokyo Electric, better known as Tepco. Even if it had returned, this robot, like all others so far designed to aid the search for the lost fuel, was expected to find its final resting place inside a reactor.

No. 1 Unit

Hitachi Corp. in the next two months plans to send a machine into the No. 1 reactor core that scientists hope can transmit photos of the fuel and measure radiation levels.

The snake-like robot will lower a camera on a wire from a grate platform in the reactor to take photos and generate 3-D models of the bottom of the containment vessel. This will be the third time Hitachi sends in this robot design.

While the company is hopeful this robot will find some of the fuel, it will likely be unable to find all of it, according to Satoshi Okada, a Hitachi engineer working on the project. The company is already planning the next robot voyage for after April.

We are gathering information so that we can decide on a way to remove the fuel,” said Okada. “Once we understand the situation inside, we will be able to see the way to remove the fuel.”

No. 2 Unit

On Thursday, Toshiba’s scorpion-like robot entered the reactor and stopped short of making it onto the containment vessel’s grate. While Tepco decided not to retrieve it, the company views the attempt as progress.

We got a very good hint as to where the fuel could be from this entire expedition” Tepco official Yuichi Okamura said Thursday at a briefing in Tokyo. “I consider this a success, a big success.”

Tepco released images last month of a grate under the No. 2 reactor covered in black residue that may be the melted fuel — one of the strongest clues yet to its location. The company measured radiation levels of around 650 sieverts per hour through the sound-noise in the video, the highest so far recorded in the Fukushima complex.

A short-term, whole-body dose of over 10 sieverts would cause immediate illness and subsequent death within a few weeks, according to the World Nuclear Association.

The Hitachi and Toshiba robots are designed to handle 1,000 sieverts and no robot has yet been disabled due to radiation.

Radiation levels near the fuel are lethal,” said MIT’s Buongiorno, who holds the university’s Tepco chair, a professorship based on an initial donation by the company 10 years ago. There are no formal affiliations or obligations for the faculty who receive the chair, he said.

Because the No. 2 unit is the only one of the three reactors that didn’t experience a hydrogen explosion, there was no release into the atmosphere and radiation levels inside the core are higher compared to the other two units, according to the utility.

No. 3 Unit

Tepco’s balance sheet has been strapped by ballooning Fukushima cleanup costs and slumping national power demand. All of the company’s nuclear power plants remain shut since it halted the No. 6 reactor at its Kashiwazaki Kariwa station in March 2012. The company is seeking drastic changes in top management in consultation with the Japanese government, TV Asahi reported Friday, without attribution.

The utility has focused on removing spent fuel in the upper part of the reactor building, which Toshiba aims to extract with a claw-like system. This fuel didn’t melt and is still in a pool that controls its temperature.

The used-fuel in No. 3 is scheduled to begin removal before the end of the decade, the first among the three reactors that melted down. Toshiba is developing another robot to search for melted fuel, planned to enter sometime in the year ending March 2018. The company hasn’t announced yet the design or strategy.

https://about.bnef.com/blog/race-for-japans-melted-nuclear-fuel-leaves-trail-of-dead-robots/

February 21, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment