Fukushima dome roof takes shape, but radiation remains high — The Asahi Shimbun

” High radiation levels are still limiting recovery work at the Fukushima No. 1 nuclear plant, a stark reality that reporters saw firsthand when they observed efforts to remove risk factors there.

Media representatives were invited into the plant in early December to see construction work, with the building of a domed roof over the No. 3 reactor building as the main focus.

However, they were only allowed to stay on top of the roof for 20 minutes due to high radiation levels.

The roof is being put together directly above the storage pool for spent fuel. The dome is designed to prevent the spewing of radioactive materials when the fuel is actually removed from the pool.

The original roof of the No. 3 reactor building was severely damaged by a hydrogen explosion in the days following the March 11, 2011, Great East Japan Earthquake and tsunami, which led to the crippling of the Fukushima No. 1 plant.

Spent fuel still remains in the storage pools located on the top floors of the No. 1 to No. 3 reactor buildings.

Plans call for removing the spent fuel first from the No. 3 reactor building.

Although the dome will help prevent the spread of radioactive materials, building parts and other debris as well as some equipment have still not been completely removed from the storage pool, which holds 566 fuel rods.

The collapsed roof and walls were removed to allow for the construction of the domed roof, which began in the summer. The domed roof is about 17 meters high, and a crane was also installed under it in November.

Plans call for the removal of the spent fuel from the No. 3 building to begin in the middle of the next fiscal year.

Internal radiation exposure levels were measured before media representatives headed to the No. 3 reactor building. They were also required to don protective clothing as well as a partial face mask covering the mouth and nose from about 100 meters from the building.

Radiation levels close to the building were 0.1 millisieverts per hour.

An elevator installed into the scaffolding next to the reactor building took the media representatives to the roof, which had been covered with metal plates.

The so-called operating floor looked like any other newly constructed building roof, a sharp contrast to the twisted metal parts that covered the building shortly after the nuclear accident.

Tokyo Electric Power Co., the plant’s operator, captured video footage from within the reactors for the first time in July. Debris that appears to be melted nuclear fuel was found in various parts of the containment vessel.

To the south of the No. 3 reactor building stands the No. 4 reactor building, from where all the spent nuclear fuel has been removed.

To the north is the No. 2 reactor building, which avoided a hydrogen explosion. Beyond the building, cranes and other large equipment are working in preparation for the removal of debris from the No. 1 reactor building.

TEPCO officials cautioned media representatives about standing too long right next to the storage pool, which could be seen located about six meters below the roof. Debris was found within the pool while insulating material floated on the pool surface.

The radiation level near the pool was 0.68 millisieverts per hour. While that was a major improvement from the 800 millisieverts per hour recorded in the immediate aftermath of the nuclear accident close to seven years ago, it was still too high to allow for a stay of longer than 20 minutes. ”

by Chikako Kawahara, The Asahi Shimbun

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Six years after Fukushima, robots finally find reactors’ melted uranium fuel — The New York Times

” FUKUSHIMA DAIICHI NUCLEAR POWER PLANT, Japan — Four engineers hunched before a bank of monitors, one holding what looked like a game controller. They had spent a month training for what they were about to do: pilot a small robot into the contaminated heart of the ruined Fukushima nuclear plant.

Earlier robots had failed, getting caught on debris or suffering circuit malfunctions from excess radiation. But the newer version, called the Mini-Manbo, or “little sunfish,” was made of radiation-hardened materials with a sensor to help it avoid dangerous hot spots in the plant’s flooded reactor buildings.

The size of a shoe box, the Manbo used tiny propellers to hover and glide through water in a manner similar to an aerial drone.

After three days of carefully navigating through a shattered reactor building, the Manbo finally reached the heavily damaged Unit 3 reactor. There, the robot beamed back video of a gaping hole at the bottom of the reactor and, on the floor beneath it, clumps of what looked like solidified lava: the first images ever taken of the plant’s melted uranium fuel.

The discovery in July at Unit 3, and similar successes this year in locating the fuel of the plant’s other two ruined reactors, mark what Japanese officials hope will prove to be a turning point in the worst atomic disaster since Chernobyl.

The fate of the fuel had been one of the most enduring mysteries of the catastrophe, which occurred on March 11, 2011, when an earthquake and 50-foot tsunami knocked out vital cooling systems here at the plant.

Left to overheat, three of the six reactors melted down. Their uranium fuel rods liquefied like candle wax, dripping to the bottom of the reactor vessels in a molten mass hot enough to burn through the steel walls and even penetrate the concrete floors below.

No one knew for sure exactly how far those molten fuel cores had traveled before desperate plant workers — later celebrated as the “Fukushima Fifty” — were able to cool them again by pumping water into the reactor buildings. With radiation levels so high, the fate of the fuel remained unknown.

As officials became more confident about managing the disaster, they began a search for the missing fuel. Scientists and engineers built radiation-resistant robots like the Manbo and a device like a huge X-ray machine that uses exotic space particles called muons to see the reactors’ innards.

Now that engineers say they have found the fuel, officials of the government and the utility that runs the plant hope to sway public opinion. Six and a half years after the accident spewed radiation over northern Japan, and at one point seemed to endanger Tokyo, the officials hope to persuade a skeptical world that the plant has moved out of post-disaster crisis mode and into something much less threatening: cleanup.

“Until now, we didn’t know exactly where the fuel was, or what it looked like,” said Takahiro Kimoto, a general manager in the nuclear power division of the plant’s operator, Tokyo Electric Power Co., or Tepco. “Now that we have seen it, we can make plans to retrieve it.”

Tepco is keen to portray the plant as one big industrial cleanup site. About 7,000 people work here, building new water storage tanks, moving radioactive debris to a new disposal site, and erecting enormous scaffoldings over reactor buildings torn apart by the huge hydrogen explosions that occurred during the accident.

Access to the plant is easier than it was just a year ago, when visitors still had to change into special protective clothing. These days, workers and visitors can move about all but the most dangerous areas in street clothes.

A Tepco guide explained this was because the central plant grounds had been deforested and paved over, sealing in contaminated soil.

During a recent visit, the mood within the plant was noticeably more relaxed, though movements were still tightly controlled and everyone was required to wear radiation-measuring badges. Inside a “resting building,” workers ate in a large cafeteria and bought snacks in a convenience store.

At the plant’s entrance, a sign warned: “Games like Pokemon GO are forbidden within the facility.”

“We have finished the debris cleanup and gotten the plant under control,” said the guide, Daisuke Hirose, a spokesman for Tepco’s subsidiary in charge of decommissioning the plant. “Now, we are finally preparing for decommissioning.”

In September, the prime minister’s office set a target date of 2021 — the 10th anniversary of the disaster — for the next significant stage, when workers begin extracting the melted fuel from at least one of the three destroyed reactors, though they have yet to choose which one.

The government admits that cleaning up the plant will take at least another three to four decades and tens of billions of dollars. A $100 million research center has been built nearby to help scientists and engineers develop a new generation of robots to enter the reactor buildings and scoop up the melted fuel.

At Chernobyl, the Soviets simply entombed the charred reactor in concrete after the deadly 1986 accident. But Japan has pledged to dismantle the Fukushima plant and decontaminate the surrounding countryside, which was home to about 160,000 people who were evacuated after accident.

Many of them have been allowed to return as the rural towns around the plant have been decontaminated. But without at least starting a cleanup of the plant itself, officials admit they will find it difficult to convince the public that the accident is truly over.

They also hope that beginning the cleanup will help them win the public’s consent to restart Japan’s undamaged nuclear plants, most of which remain shut down since the disaster.

Tepco and the government are treading cautiously to avoid further mishaps that could raise doubts that the plant is under control.

“They are being very methodical — too slow, some would say — in making a careful effort to avoid any missteps or nasty surprises,” said David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists, who was a co-author of a book on the disaster.

“They want to regain trust. They have learned that trust can be lost much quicker than it can be recovered.”

To show the course followed by the Manbo, Tepco’s Mr. Hirose guided me inside the building containing the undamaged Unit 5 reactor, which is structurally the same as two of the destroyed reactors.

Mr. Hirose pointed toward the spot on a narrow access ramp where two robots, including one that looked like a scorpion, got tangled in February by debris inside the ruined Unit 2.

Before engineers could free the scorpion, its monitoring screen faded to black as its electronic components were overcome by radiation, which Tepco said reached levels of 70 sieverts per hour. (A dose of one sievert is enough to cause radiation sickness in a human.)

Mr. Hirose then led me underneath the reactor, onto what is called the pedestal.

The bottom of the reactor looked like a collection of huge bolts — the access points for control rods used to speed up and slow down the nuclear reaction inside a healthy reactor. The pedestal was just a metal grating, with the building’s concrete floor visible below.

“The overheated fuel would have dropped from here, and melted through the grating around here,” Mr. Hirose said, as we squatted to avoid banging our heads on the reactor bottom. The entire area around the reactor was dark, and cluttered with pipes and machinery.

To avoid getting entangled, the Manbo took three days to travel some 20 feet to the bottom of Unit 3.

To examine the other two reactors, engineers built a “snake” robot that could thread its way through wreckage, and the imaging device using muons, which can pass through most matter. The muon device has produced crude, ghostly images of the reactors’ interiors.

Extracting the melted fuel will present its own set of technical challenges, and risks.

Engineers are developing the new radiation-resistant robots at the Naraha Remote Technology Development Center. It includes a hangar-sized building to hold full-scale mock-ups of the plant and a virtual-reality room that simulates the interiors of the reactor buildings, including locations of known debris.

“I’ve been a robotic engineer for 30 years, and we’ve never faced anything as hard as this,” said Shinji Kawatsuma, director of research and development at the center. “This is a divine mission for Japan’s robot engineers.” “

by Martin Fackler, The New York Times

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Radioactivity and Operation Tomodachi documentary — Dailymotion

Here is an excellent documentary of the young military service men and women who aided the Japanese following the tsunami on March 11, 2011. They were exposed to high levels of radiation during their mission, Operation Tomodachi (which means friend in Japanese). They are in an ongoing class action lawsuit against the Fukushima No. 1 Nuclear Power Plant operator, Tokyo Electric Power Company (TEPCO), for allegedly not warning the military personnel of the high levels of radiation released from the power plant during the triple meltdowns. As a result, hundreds of these young men and women are suffering from debilitating health conditions, including cancer, and are seeking financial support and accountability. This documentary is in Japanese, but it is still worth watching.

published on Dailymotion

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Fukushima evacuee to tell UN that Japan violated human rights — The Guardian

” A nuclear evacuee from Fukushima will claim Japan’s government has violated the human rights of people who fled their homes after the 2011 nuclear disaster, in testimony before the UN in Geneva this week.

Mitsuko Sonoda, who voluntarily left her village with her husband and their 10-year-old son days after three reactors at the Fukushima Daiichi nuclear power plant went into meltdown, will tell the UN human rights council that evacuees face financial hardship and are being forced to return to neighbourhoods they believe are still unsafe almost seven years after the disaster.

“We feel abandoned by the Japanese government and society,” Sonoda, who will speak at the council’s pre-session review of Japan on Thursday, told the Guardian.

An estimated 27,000 evacuees who, like Sonoda, were living outside the mandatory evacuation zone when the meltdown occurred, had their housing assistance withdrawn this March, forcing some to consider returning to their former homes despite concerns over radiation levels.

In addition, as the government attempts to rebuild the Fukushima region by reopening decontaminated neighbourhoods that were once no-go areas, tens of thousands of evacuees who were ordered to leave will lose compensation payments and housing assistance in March next year.

The denial of financial aid has left many evacuees facing a near-impossible choice: move back to homes they fear are unsafe, or face more financial hardship as they struggle to build lives elsewhere without state help.

“People should be allowed to choose whether or not to go back to their old homes, and be given the financial means to make that choice,” said Kendra Ulrich, senior global energy campaigner for Greenpeace Japan.

“If they are being put under economic pressure to return, then they are not in a position to make an informed decision. This UN session is about pressuring the Japanese government to do the right thing.”

Evacuees are being encouraged to return to villages and towns near the Fukushima plant despite evidence that some still contain radiation “hot spots”.

In Iitate village, where the evacuation order was lifted this March, much of the surrounding forests remain highly radioactive, although homes, schools and other public buildings have been declared safe as part of an unprecedented decontamination effort.

“You could call places like Iitate an open-air prison,” said Ulrich. “The impact on people’s quality of life will be severe if they move back. Their lives are embedded in forests, yet the environment means they will not be allowed to enter them. Forests are impossible to decontaminate.”

After months of moving around, Sonoda and her family settled in Kyoto for two years, where local authorities provided them with a rent-free apartment. They have been living in her husband’s native England for the past four years.

“We’ve effectively had to evacuate twice,” said Sonoda, who works as a freelance translator and Japanese calligraphy tutor. “My son and I really struggled at first … we didn’t want to leave Japan.”

Concern over food safety and internal radiation exposure convinced her that she could never return to Fukushima, aside from making short visits to see relatives. “It’s really sad, because my village is such a beautiful place,” she said. “We had a house and had planned to retire there.”

The evacuations have forced families to live apart, while parents struggle to earn enough money to fund their new accommodation and keep up mortgage payments on their abandoned homes.

“Stopping housing support earlier this year was an act of cruelty,” Sonoda said. “Some of my friends had to go back to Fukushima even though they didn’t want to.”

Greenpeace Japan, which is assisting Sonoda, hopes her testimony will be the first step in building international pressure on Japan’s government to continue offering financial help to evacuees and to reconsider its resettlement plan.

It has called on the government to declare Fukushima neighbourhoods unsafe until atmospheric radiation is brought to below one millisievert (mSv) a year, the maximum public exposure limit recommended by the International Commission on Radiological Protection.

While 1 mSv a year remains the government’s long-term target, it is encouraging people to return to areas where radiation levels are below 20 mSv a year, an annual exposure limit that, internationally, applies to nuclear power plant workers.

“Why should people, especially women and children, have to live in places where the radiation level is 20 times the international limit?” Sonoda said. “The government hasn’t given us an answer.” ”

by The Guardian

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Fukushima court rules Tepco, government liable over 2011 disaster — Reuters

” TOKYO (Reuters) – A district court in Fukushima prefecture on Tuesday ruled that Tokyo Electric Power and the Japanese government were liable for damages totaling about 500 million yen ($4.44 million) in the largest class action lawsuit brought over the 2011 nuclear disaster, Kyodo news agency said.

A group of about 3,800 people, mostly in Fukushima prefecture, filed the class action suit, marking the biggest number of plaintiffs out of about 30 similar class action lawsuits filed across the nation.

This is the second court ruling that fixed the government’s responsibility after a Maebashi district court decision in March.

All the three district court decisions so far have ordered Tepco to pay damages. Only the Chiba court decision last month did not find the government liable for compensation.

The plaintiffs in Fukushima case have called on defendants for reinstating the levels of radioactivity at their homes before the disaster, but the court rejected the request, Kyodo said.

Tepco has long been criticized for ignoring the threat posed by natural disasters to the Fukushima plant and the company and the government were lambasted for their handling of the crisis. “

reporting by Osamu Tsukimori and Aaron Sheldrick; editing by Christian Schmollinger and Gopakumar Warrier, Reuters

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Tepco to delay emptying fuel storage pools at Fukushima plant — The Asahi Shimbun

” Plans to remove fuel rods from two spent fuel pools at the Fukushima No. 1 nuclear plant will be delayed by up to three years because of difficulties in clearing debris and reducing radiation levels.

The government and plant operator Tokyo Electric Power Co. originally expected to start emptying the storage pools at the No. 1 and No. 2 reactor buildings in fiscal 2020.

But they plan to move the starting time to fiscal 2023 in their first review in two years of the roadmap for decommissioning the stricken nuclear plant, sources said Sept. 20.

They are expected to announce the revised roadmap later this month.

A survey of the upper levels of the two reactor buildings, where the storage pools are located, found debris piled up in a much more complicated way than initially envisaged.

That will lengthen the time needed to clear the debris, thus delaying the removal of the fuel rods, the sources said.

In addition, radiation levels remain extremely high inside the buildings.

The No. 1 reactor’s storage pool holds 392 nuclear fuel assemblies, while the No. 2 reactor’s pool has 615 assemblies.

Work to remove the 566 assemblies from the No. 3 reactor’s pool is scheduled to begin in the middle of fiscal 2018 as originally planned.

The three reactors melted down in the 2011 disaster, triggered by the magnitude-9.0 Great East Japan Earthquake and tsunami.

The review of the decommissioning roadmap is also expected to revise the target of “starting the removal” of melted nuclear fuel and debris in the three reactors in 2021 to “aiming to start the removal” in 2021.

But the government and TEPCO will maintain the goal of completing the decommissioning in “30 to 40 years,” the sources said. ”

by Chikako Kawahara, The Asahi Shimbun

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