Fukushima dome roof takes shape, but radiation remains high

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Construction continues on a domed roof on top of the No. 3 reactor building at the Fukushima No. 1 nuclear power plant.
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.
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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.
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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.
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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.
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Vietnam’s ex-president admits Fukushima disaster played role in ditching foray into atomic power

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HO, CHI MINH CITY – Vietnam last year abandoned plans to build its first nuclear power plants with Japanese and Russian assistance due to heightened concern over the safety of atomic power following events including the Fukushima disaster, according to former President Truong Tan Sang.
“The situation in the world had changed,” Sang, 68, said in an interview in Ho Chi Minh City on Thursday. “Due to the fluctuations of the world situation, the Vietnamese people were very worried, especially the people in the area where the nuclear power plants were to be located. They had reactions. Therefore, we had to temporarily halt (the plans).”
The interview was his first with a foreign media outlet since stepping down from the post in April last year.
In scrapping the plans to build two multibillion-dollar nuclear plants in November last year, the government cited the country’s tight financial situation, claiming at the time that safety was not an issue.
On Vietnam’s territorial row with China in the South China Sea, Sang said his country welcomes the concerns of countries in and outside the region to contribute to ensuring peace and stability in the strategic waterway.
“We protect our interests on the basis of international law, and at the same time we also respect the interests of the countries concerned on the basis of international law,” he said.
“Japan is very close to Vietnam’s view,” he added, expressing hope for Tokyo’s continued support for its stance in the dispute.
On the economic front, he praised Japan for its active promotion of globalization, especially after U.S. President Donald Trump withdrew from the Trans-Pacific Partnership, a free trade agreement signed by 12 nations, including Vietnam and Japan.
“(Prime Minister) Shinzo Abe was one of the first leaders to promote and connect remaining countries together. As a result, at the APEC meeting in Danang recently, the TPP 11 meeting successfully took place,” he said.
On bilateral relations, he said the relationship between the two countries is “very good. There is no obstacle.”
“The extensive strategic partnership in all areas has been strengthened, bringing clear benefits,” he said.
By taking advantage of Japan’s advanced technology and Vietnam’s abundant natural and human resources, he expressed hope for greater cooperation in areas such as high-quality infrastructure, high-tech agriculture and renewable energy.
“Vietnam learns from the experience and realities of countries around the world to perfect the organizational model of our political system,” he said, indicating the necessity of reform of Vietnam’s ruling Communist Party and government based on global trends and the domestic situation.

Image shows extent of damage to reactor at Fukushima plant

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Severely damaged parts of a device once used to move control rods are stuck in a hole inside the pressure vessel of the No. 3 reactor at the Fukushima No. 1 nuclear plant. (Provided by International Research Institute for Nuclear Decommissioning)
An image taken by an underwater robot shows corroded tubes stuck in a hole created by melted fuel in the pressure vessel of the No. 3 reactor at the Fukushima No. 1 nuclear plant.
The image offers clues on the extent of the damage caused when fuel rods in the reactor melted through the bottom of the pressure vessel after the disaster at the nuclear plant unfolded in March 2011.
Tokyo Electric Power Co., operator of the plant, sent the specially designed robot into the reactor in July. The company earlier released images taken by the robot that showed ‘what is believed‘ to be melted nuclear fuel debris.
In the image released on Nov. 30, TEPCO identified the severely corroded and damaged tubes as parts of a device used to move control rods. Normally, that device is located inside the pressure vessel.
TEPCO on Nov. 30 also said it would conduct another study inside of the containment vessel of the No. 2 reactor at the plant in January. The containment vessel surrounds the pressure vessel.
A telescopic stick more than 10 meters long and equipped with a camera will be used for the survey.

Marine radioecology after the Fukushima Dai-ichi nuclear accident: Are we better positioned to understand the impact of radionuclides in marine ecosystems?

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Highlights
• Marine radioecology studies at the FDNPP coast: process-based modelling and field investigations
• Dynamic modelling of transfer between seawater, sediments and the biological compartments
• New data on submarine groundwater discharges and ocean circulation of radionuclides
• We formulate a strategy for marine radioecology based on processes-based research.
• We highlight the need for more ecology knowledge in marine radioecology.
Abstract
This paper focuses on how a community of researchers under the COMET (CO-ordination and implementation of a pan European projecT for radioecology) project has improved the capacity of marine radioecology to understand at the process level the behaviour of radionuclides in the marine environment, uptake by organisms and the resulting doses after the Fukushima Dai-ichi nuclear accident occurred in 2011. We present new radioecological understanding of the processes involved, such as the interaction of waterborne radionuclides with suspended particles and sediments or the biological uptake and turnover of radionuclides, which have been better quantified and mathematically described.
We demonstrate that biokinetic models can better represent radionuclide transfer to biota in non-equilibrium situations, bringing more realism to predictions, especially when combining physical, chemical and biological interactions that occur in such an open and dynamic environment as the ocean. As a result, we are readier now than we were before the FDNPP accident in terms of having models that can be applied to dynamic situations.
The paper concludes with our vision for marine radioecology as a fundamental research discipline and we present a strategy for our discipline at the European and international levels. The lessons learned are presented along with their possible applicability to assess/reduce the environmental consequences of future accidents to the marine environment and guidance for future research, as well as to assure the sustainability of marine radioecology. This guidance necessarily reflects on why and where further research funding is needed, signalling the way for future investigations.

Japan is poised to release into the Pacific one million tons of radioactive water contaminated by the Fukushima Daiichi nuclear plant

Fukushima’s radioactive water grows by 150 tons a day and Japan doesn’t know what to do with it. Scientists vs fishermen and locals conflict.
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Japan is poised to flood the Pacific with one million tons of nuclear water contaminated by the Fukushima power plant

Japan urged by experts to gradually release radioactive water into Pacific Ocean
Comes more than six years after tsunami overwhelmed Fukushima nuclear plant
The water is stored on site in around 900 large and densely packed tanks
But if the tank breaks, the contents may not be able to be controlled
The Japanese government is being urged by experts to gradually release radioactive water in to the Pacific Ocean more than six years after a tsunami overwhelmed the Fukushima nuclear power plant.
The water is stored on site in around 900 large and densely packed tanks and could spill should another major disaster strike.
The government has been urged to release the water into the ocean as all the radioactive elements of the water except tritium – which has been said to be safe in small amounts – have been removed through treatment.
But if the tank breaks, the contents may not be able to be controlled.
Local fishermen are extremely hesitant to this solution because many consumers are still uncertain to eat fish caught off Fukushima, despite tests that say the fish is safe to eat.
Today only about half of the region’s 1,000 fishermen go out and just twice a week because of reduced demand.
Fumio Haga, a drag-net fisherman, said: ‘People would shun Fukushima fish again as soon as the water is released.’
Lab technicians mince fish samples at Onahama port in Iwaki, pack them in a cup for inspection and record details such as who caught the fish and where.
Packaged fish then sold at supermarkets carry official ‘safe’ stickers.
Only three kinds of fish passed the test when the experiment began in mid-2012, 15 months after the tsunami.
Over time, that number has increased to about 100.
The fish meet what is believed to be the world’s most stringent requirement: less than half the radioactive cesium level allowed under Japan’s national standard and one-twelfth of the US or EU limit, said Yoshiharu Nemoto, a senior researcher at the Onahama testing station.
The amount of radioactive water at Fukushima is still growing, by 150 tons a day.
The reactors are damaged beyond repair, but cooling water must be constantly pumped in to keep them from overheating.
That water picks up radioactivity before leaking out of the damaged containment chambers and collecting in the basements.
There, the volume of contaminated water grows, because it mixes with groundwater that has seeped in through cracks in the reactor buildings.
After treatment, 210 tons is reused as cooling water, and the remaining 150 tons is sent to tank storage.
During heavy rains, the groundwater inflow increases significantly, adding to the volume.
The water is a costly headache for Tokyo Electric Power Co, the utility that owns the plant.
To reduce the flow, it has dug dozens of wells to pump out groundwater before it reaches the reactor buildings and built an underground ‘ice wall’ of questionable effectiveness by partially freezing the ground around the reactors.
Another government panel recommended last year that the utility, known as TEPCO, dilute the water up to about 50 times and release about 400 tons daily to the sea – a process that would take almost a decade to complete.
Experts note that the release of radioactive tritium water is allowed at other nuclear plants.

Fukushima ‘ice wall’ linchpin not living up to high hopes

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Although 34.5 billion yen ($309 million) in taxpayer money has funded an “ice wall” to keep out groundwater from the Fukushima No. 1 nuclear power plant site, the frozen barrier may not be meeting hopes and expectations.
In particular, the wall has been vulnerable to heavy rain brought by typhoons.
Reducing the volume of radiation-contaminated water is vital to proceeding with the removal of melted fuel from the reactors at the Fukushima No. 1 plant so it can be decommissioned.
But officials of Tokyo Electric Power Co., the operator of the plant, are still not completely sure if the ice wall is performing as designed.
Heavy rain appears to pose a major problem because the ice wall has so far proved incapable of stopping groundwater when typhoons have passed near the plant.
In theory, the ice wall should serve as a dam to prevent groundwater from the mountainside of the plant from flowing into the reactor buildings.
The total length of the wall is about 1,500 meters, and the wall surrounds the reactor and turbine buildings of four reactors at the No. 1 plant. Pipes have been buried about 30 meters deep at one-meter intervals.
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Liquid at temperatures of minus 30 degrees have been poured into the pipes to freeze the surrounding ground. Freezing of the final section of the wall began on Aug. 22, but TEPCO officials on Nov. 22 still stopped short of offering an assessment of whether the ice wall was actually working as planned.
Utility officials have said that after about two months, ground temperatures where the freezing had begun have fallen below 0 degrees.
The estimated volume of groundwater that has leaked into the reactor and other buildings was 190 tons a day at the start of 2016, but it had decreased to 110 tons a day by early October.
However, the situation changed dramatically when two typhoons passed by in late October.
The groundwater level rose rapidly and the average daily flow of groundwater into the building basements for October was estimated to be 310 tons. That was close to the 400 tons that was flowing into the building basements before any measures were implemented to deal with the contaminated water.
There was no realistic expectation of building a ice wall that would keep out all groundwater because the pipes had to be buried in a way that would avoid underground piping from the reactors that were already in place. That meant there were underground portions that could not be frozen.
Masashi Kamon, a professor emeritus at Kyoto University who specializes in environmental geotechnics, said TEPCO should have considered a number of measures to stem the flow of groundwater from the long-term perspective of eventually removing the melted fuel from the reactors.
Another measure that is receiving more attention of late is pumping up groundwater from the 42 wells located around the reactor buildings and releasing it into the ocean. TEPCO plans to double the number of pumps and processing capacity of decontamination facilities by early 2018.
But other measures will likely have to be considered before work can begin to remove melted fuel from the reactor cores. The first step would be to remove as much as possible the highly radioactive water that remains in the reactor building basements. Such water poses a huge risk to the workers who will have to enter the buildings to remove the fuel.
Toyoshi Fuketa, chairman of the Nuclear Regulation Authority, said the ice wall was a measure implemented when the situation was much more serious, but that now is the time for calmer consideration about whether that investment of time and money was the proper one.

Japan still at a stalemate as Fukushima’s radioactive water grows by 150 tons a day

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A Tepco official wearing radioactive protective gear stands in front of Advanced Liquid Processing Systems during a media tour at the Fukushima No. 1 nuclear power plant in November 2014.
ONAHAMA, FUKUSHIMA PREF. – More than six years after a tsunami overwhelmed the Fukushima No. 1 nuclear power plant, Japan has yet to reach consensus on what to do with a million tons of radioactive water, stored on site in around 900 large and densely packed tanks that could spill should another major earthquake or tsunami strike.
The stalemate is rooted in a fundamental conflict between science and human nature.
Experts advising the government have urged a gradual release to the Pacific Ocean. Treatment has removed all the radioactive elements except tritium, which they say is safe in small amounts. Conversely, if the tanks break, their contents could slosh out in an uncontrolled way.
Local fishermen are balking. The water, no matter how clean, has a dirty image for consumers, they say. Despite repeated tests showing most types of fish caught off Fukushima are safe to eat, diners remain hesitant. The fishermen fear any release would sound the death knell for their nascent and still fragile recovery.
“People would shun Fukushima fish again as soon as the water is released,” said Fumio Haga, a drag-net fisherman from Iwaki, a city about 50 kilometers (30 miles) down the coast from the nuclear plant.
And so the tanks remain.
Fall is high season for saury and flounder, among Fukushima’s signature fish. It was once a busy time of year when coastal fishermen were out every morning.
Then came March 11, 2011. A magnitude 9 offshore earthquake triggered a tsunami that killed more than 18,000 people along the coast. The quake and massive flooding knocked out power for the cooling systems at the Fukushima nuclear plant. Three of the six reactors had partial meltdowns. Radiation spewed into the air, and highly contaminated water ran into the Pacific.
Today, only about half of the region’s 1,000 fishermen go out, and just twice a week because of reduced demand. They participate in a fish testing program.
Lab technicians mince fish samples at Onahama port in Iwaki, pack them in a cup for inspection and record details such as who caught the fish and where. Packaged fish sold at supermarkets carry official “safe” stickers.
Only three kinds of fish passed the test when the experiment began in mid-2012, 15 months after the tsunami. Over time, that number has increased to about 100.
The fish meet what is believed to be the world’s most stringent requirement: less than half the radioactive cesium level allowed under Japan’s national standard and one-twelfth of the U.S. or EU limit, said Yoshiharu Nemoto, a senior researcher at the Onahama testing station.
That message isn’t reaching consumers. A survey by the Consumer Affairs Agency in October found that nearly half of Japanese weren’t aware of the tests, and that consumers are more likely to focus on alarming information about possible health impacts in extreme cases, rather than facts about radiation and safety standards.
Fewer Japanese consumers shun fish and other foods from Fukushima than before, but 1 in 5 still do, according to the survey. The coastal catch of 2,000 tons last year was 8 percent of pre-disaster levels. The deep-sea catch was half of what it used to be, though scientists say there is no contamination risk that far out.
Naoya Sekiya, a University of Tokyo expert on disaster information and social psychology, said that the water from the nuclear plant shouldn’t be released until people are well-informed about the basic facts and psychologically ready.
“A release only based on scientific safety, without addressing the public’s concerns, cannot be tolerated in a democratic society,” he said. “A release when people are unprepared would only make things worse.”
He and consumer advocacy group representative Kikuko Tatsumi sit on a government expert panel that has been wrestling with the social impact of a release and what to do with the water for more than a year, with no sign of resolution.
Tatsumi said the stalemate may be further fueling public misconception: Many people believe the water is stored because it’s not safe to release, and they think Fukushima fish is not available because it’s not safe to eat.
The amount of radioactive water at Fukushima is still growing, by 150 tons a day.
The reactors are damaged beyond repair, but cooling water must be constantly pumped in to keep them from overheating. That water picks up radioactivity before leaking out of the damaged containment chambers and collecting in the basements.
There, the volume of contaminated water grows, because it mixes with groundwater that has seeped in through cracks in the reactor buildings. After treatment, 210 tons is reused as cooling water, and the remaining 150 tons is sent to tank storage. During heavy rains, the groundwater inflow increases significantly, adding to the volume.
The water is a costly headache for Tokyo Electric Power Company Holdings Inc., the utility that owns the plant. To reduce the flow, it has dug dozens of wells to pump out groundwater before it reaches the reactor buildings and built an underground “ice wall” of questionable effectiveness by partially freezing the ground around the reactors.
Another government panel recommended last year that the utility, known as Tepco, dilute the water up to about 50 times and release about 400 tons daily to the sea — a process that would take almost a decade to complete. Experts note that the release of tritiated water is allowed at other nuclear plants.
Tritiated water from the 1979 Three Mile Island accident in the United States was evaporated, but the amount was much smaller, and still required 10 years of preparation and three more years to complete.
A new chairman at Tepco, Takashi Kawamura, caused an uproar in the fishing community in April when he expressed support for moving ahead with the release of the water.
The company quickly backpedaled, and now says it has no plans for an immediate release and can keep storing water through 2020. Tepco says the decision should be made by the government, because the public doesn’t trust the utility.
“Our recovery effort up until now would immediately collapse to zero if the water is released,” Iwaki abalone farmer Yuichi Manome said.
Some experts have proposed moving the tanks to an intermediate storage area, or delaying the release until at least 2023, when half the tritium that was present at the time of the disaster will have disappeared naturally.