METI eyes 2031 end to Fukushima No. 1 cleanup — The Japan Times via Nuclear News

This article was taken off The Japan Times website, but was reblogged on Nuclear News here. It was written by Mari Yamaguchi and published on Dec. 2, 2019.

” The industry ministry on Monday unveiled a revised plan to remove molten nuclear fuel debris from the meltdown-hit Fukushima No. 1 power plant in 2021 — a process said to be the biggest hurdle to decommissioning the six-reactor facility.

Work to remove the debris should start with the No. 2 reactor, according to the mid- to long-term road map released by the government.

Designating a specific time frame for the first time, the plan also calls for completing the removal of 4,741 fuel rods left inside the cooling pools for reactor Nos. 1 to 6 by 2031.

“As more people return and rebuilding progresses in the areas around the No. 1 plant, we will take measures based on the basic principle of balancing rebuilding and decommissioning,” said Minister of Economy, Trade and Industry Hiroshi Kajiyama, who heads the state team tasked with decommissioning the heavily damaged plant.

The plan, revised for the fifth time, maintains the general outlook for finishing the cleanup within 30 to 40 years of the triple meltdown, which was triggered by the mega-quake and tsunami on March 11, 2011. But, given issues that have halted work and caused delays so far, it remains uncertain whether the plan will proceed as scheduled.

Here is a look at some of the challenges facing Fukushima No. 1:

Melted fuel debris

By far the toughest challenge is removing the 800 tons of nuclear fuel that melted in the three reactors before dropping from their cores and hardening at the bottom of the primary containment vessels.

Over the past two years, Tepco has made progress gathering details mainly from two of the reactors. In February, a small telescopic robot sent inside the No. 2 reactor showed that small pieces of debris can come off and be lifted out. Thus debris removal is scheduled to begin there by the end of 2021.

Earlier, assessments of the No. 3 reactor were hampered by high radiation and water levels in the PCVs. A robot survey at the No. 1 reactor also failed from extremely high radiation.

Experts say a 30- to 40-year completion decommissioning target is too optimistic. Some doubt that removing all of the fuel is even doable and suggest an approach like Chernobyl — contain the reactors and wait until radioactivity naturally fades.

Fuel rods

Together, the three reactors have more than 1,500 units of mostly spent nuclear fuel rods inside that must be kept cool in pools of water. They’re among the highest risks at the plant because the pools are uncovered, and loss of water from structural damage or sloshing in the event of another major quake could cause them to melt and release massive radiation.

The manager of the plant, Tokyo Electric Power Company Holdings Inc., started removing rods from the No. 3 reactor pool in April and aims to get all 566 out by March 2021. Removal of rods from units 1 and 2 is to begin in 2023.

By 2031, Tepco plans to remove thousands of rods at the two units that survived the tsunami and store them in dry casks on the compound. Over 6,300 fuel rods were in the six reactor cooling pools at the time, and only the pool at No. 4 has been emptied.

Tainted water

The government and Tepco have been unable to get rid of the more than 1 million tons of radioactive water that has been treated and stored on site, fearing public repercussions. The utility has managed to cut the volume by pumping up and diverting groundwater upstream, as well as by installing a costly underground “ice wall” around the reactor buildings to keep water from entering.

Tepco says it only has space for up to 1.37 million tons until summer 2022, raising speculation it might release the tainted water after the 2020 Olympics. Tepco and experts say that the tanks are hampering decommissioning work and that the space they occupy must be freed up to build storage for the debris and other radioactive materials to be removed. There is also the risk that the tanks might fail and release their contents in the event of another quake, tsunami or flood.

Experts say a controlled release of the water into the ocean is the only realistic option, one that will take decades. For years, a government panel has been discussing methods amid opposition from fishermen and residents who fear it will damage their products and their health.

Radioactive waste

Japan has yet to develop a plan to dispose of the highly radioactive waste that will come out of the reactors. Under the road map, the government and Tepco will compile a plan sometime after the first decade of removal work ends in 2031.

Managing the waste will require new technologies to compact it and reduce its toxicity. Tepco and the government say they plan to build a temporary storage site for the waste. But finding a site and getting public consent to store it there will be nearly impossible, raising doubts the cleanup can be finished within 40 years.

Manpower concerns

Securing a workforce for the decades-long project is yet another challenge, especially in a country with a rapidly aging and declining population. Tepco announced plans to hire foreign workers for the decommissioning process under Japan’s new visa program to attract unskilled foreign labor, but put it on hold after receiving government instructions on careful planning to address concerns about language problems and safety. Universities are also struggling to attract students in nuclear science, a formerly elite major that has become unpopular since the Fukushima crisis. “

Radioactive water at Fukushima should be stored not dumped — Beyond Nuclear International

” Last week, Japan’s then environment minister, Yoshiaki Harada, made news with a pronouncement that wasn’t news. The storage tanks at the stricken Fukushima Daiichi nuclear site, filled with radioactive water, were reaching capacity. By 2022 there would be no room for more tanks on the present site. Japan would then have to dump the radioactive water stored in the tanks into the Pacific Ocean, he said.

Although likely unrelated to those remarks, a day later, Prime Minister Shinzo Abe dispatched 19 of his cabinet ministers, including Harada. Harada was replaced as environment minister by rising star, Shinjiro Koizumi, the son of former primer minister, Junichiro Koizumi. Both father and son are opposed to nuclear energy, and on his first day in office, the younger Koizumi told reporters that he believed Japan should end its use of nuclear energy and close its nuclear power plants.

“I would like to study how we scrap them, not how to retain them,” Reuters reported him saying. This is a surprising position from someone inside the fervently pro-nuclear Abe government and it remains to be seen whether he will be allowed to translate his position into policy.

Dumping Fukushima Daiichi’s accumulated radioactive water has long been the plan proposed by Tepco, the site owner. Fukushima fishermen, along with some scientists and a number of NGOs from around the world, continue to object.

Cooling water is needed at the Fukushima site because, when Units 1, 2 and 3 lost power, they also lost the flow of reactor coolant, causing their cores to overheat. The fuel rods then melted, and molten fuel dripped down and burned through the pressure vessels, pooling in the primary containment vessels. Units 1, 3 and 4 also suffered hydrogen explosions. Each day, about 200 metric tons of cooling water is used to keep the three melted cores cool, lest they once more go critical. Eventually the water becomes too radioactive and thermally hot to be re-used, and must be discarded and stored in the tanks.

As Greenpeace International (GPI) explained in remarks and questions submitted during a consultative meeting held by the International Maritime Organization in August 2019:

“Since 2011, in order to cool the molten cores in the Tokyo Electric Power Company Fukushima Daiichi reactor units 1-3, water is continuously pumped through the damaged Reactor Pressure Vessels (RPVs) and circulated through reactor buildings, turbine buildings, the Process Main Building and the “High Temperature Incinerator Building”  and water treatment systems.

“As a result, the past eight years has seen a relentless increase in the volume of radioactive contaminated water accumulating on site. As of 4 July 2019, the total amount of contaminated water held in 939 storage tanks at the Fukushima Daiichi plant (units 1-4) was 1,145,694 m3 (tonnes). The majority of this, 1,041,710 m3, is contaminated processed water. In the year to April 2019, approximately 180 m3/day of water was being circulated into the RPVs of units 1-3.”

In addition to the cooling water, the tanks also house water that has run down from the nearby mountains, at a rate of about 100 tons each day. This water flows onto the site and seeps into the reactor buildings. There, it becomes radioactively contaminated and also must be collected and stored, to prevent it from flowing on down into the sea.

The water tank crisis is just one of multiple and complex problems at the Fukushima Daiichi site, including the eventual need to extract the molten fuel debris from inside the stricken reactors. Decommissioning cannot begin until the water storage tanks are removed.

Tepco has tried to mitigate the radioactive water problem in a number of ways. The infamous $320 million ice wall was an attempt to freeze and block inflow, but has had mixed results and has worked only intermittently. Wells were dug to try to divert the runoff water so it does not pick up contamination. The ice wall has reportedly reduced the flow of groundwater somewhat, but only down from 500 tons a day to about 100 tons.

In anticipation of dumping the tank water into the Pacific Ocean, Tepco has deployed an Advanced Liquid Processing System that the company claims can remove 62 isotopes from the water — all except tritium, which is radioactive hydrogen and therefore cannot be filtered out of water. (Tritium is routinely discharged by operating commercial nuclear power plants).

But, like the ice wall, the filtration system has also been plagued by malfunctions. According to GPI, Tepco admitted only last year that the system had “failed to reduce radioactivity to levels below the regulatory limit permissible for ocean disposal” in at least 80% of the tanks’ inventory. Indeed, said GPI, “the levels of Strontium-90 are more than 100 times the regulatory standard according to TEPCO, with levels at 20,000 times above regulations in some tanks.”

The plan to dump the water has raised the ire of South Korea, whose fish stocks would likely also be contaminated. And it has introduced the question of whether such a move is a violation of The Conventions of the Rights of the Child and the Universal Declaration of Human Rights, as was raised in a joint written statement by the International Association of Democratic Lawyers and Greenpeace International, before the UN Human Rights Council currently in session.

So what else could or should Tepco do, if not dump the water offshore and into the ocean? A wide consensus amongst scientific, environmental and human rights groups is that on-site storage for the indefinite future is the only acceptable option, while research must continue into possible ways to extract all of the radioactive content, including tritium.

Meanwhile, a panel of experts says it will examine a number of additional but equally problematic choices, broadly condensed into four options (each with some variations — to  dilute or not to dilute etc):

• Ground (geosphere) injection (which could bring the isotopes in contact with groundwater);
• Vapor release (which could infiltrate weather patterns and return as fallout);
• Releasing it as hydrogen (it would still contain tritium gas); and
• Solidification followed by underground burial (for which no safe, permanent storage environment has yet been found, least of all in earthquake-prone Japan).

Arnie Gundersen of Fairewinds, recommends a chemical injection processes (drilling mud) — also used by the oil industry — to stop the flow of water onto the site entirely. But he says Japan has never considered this option. GPI contends that Japan has never seriously researched any of the alternatives, sticking to the ocean dumping plan, the cheapest and fastest “fix.”

All of this mess is of course an inevitable outcome of the choice to use nuclear power in the first place. Even without an accident, no safe, permanent storage solution has been found for the high-level radioactive waste produced through daily operation of commercial nuclear power plants, never mind as the result of an accident.

According to Dr. M.V. Ramana, by far the best solution is to continue to store the radioactive water, even if that means moving some of the storage tanks to other locations to make more room for new ones at the nuclear site. The decision to dump the water, Ramana says, is in line with Abe’s attempts to whitewash the scene before the 2020 Tokyo Olympics and claim, as he has publicly in the past, that everything at Fukushima is “under control.” (Baseball and softball games will be played in Fukushima Prefecture and the torch relay will start there, all in an effort to pretend there are no dangerous nuclear after-effects remaining in the area.)

“The reason that they keep saying they need to release it is because they might have to move some of this offsite and that goes against the Abe government’s interest in creating the perception that Fukushima is a closed chapter,” Ramana wrote in an email. “So it is a political decision rather than a technical one.”

As with all things nuclear, there are diverging views on the likely impact to the marine environment and to human health, from dumping Fukushima’s radioactive water into the ocean. These run the gamut from “a little tritium won’t hurt you” to “the Pacific Ocean is dead thanks to Fukushima” — both of which are wildly untrue. (Tritium can bind organically inside the body, irradiating that person or animal from within. The many problems in the Pacific began long before Fukushima and are likely caused by numerous compounding factors, including warming and pollution, with Fukushima adding to the existing woes.)

What is fact, however, is that scientists have found not only the presence of isotopes such as cesium in fish they tested, but also in ocean floor sediment. This latter has the potential to serve as a more long-term source of contamination up the food chain.

But it is also important to remember that if this radioactive water is dumped, it is not an isolated event. Radioactive contamination in our oceans is already widespread, a result of years of atmospheric atomic tests. As was reported earlier this year, scientists studying deep-sea amphipods, retrieved from some of the deepest trenches in the ocean — including the Mariana Trench which reaches 36,000 feet below sea-level and is deeper than Mount Everest is high — detected elevated levels of carbon-14 in these creatures.

“The levels closely matched abundances found near the surface of the ocean, where the amount of carbon-14 is higher than usual thanks to nuclear bomb tests conducted more than half a century ago,” reported Smithsonian Magazine.

Weidong Sun, co-author of the resulting study, told Smithsonian Magazine that “Biologically, [ocean] trenches are taken to be the most pristine habitats on Earth”.

How chilling, then, to realize that our radioactive irresponsibility has reached the lowest depths, affecting creatures far removed from our rash behaviors.

Consequently, the decision by the Japanese government to release yet more radioactive contamination into our oceans must be viewed not as a one-off act of desperation, but as a contribution to cumulative contamination. This, added to the twin tragedies of climate crisis-induced ocean warming and plastics and chemicals pollution, renders it one more crime committed on the oceans, ourselves and all living things. And it reinforces the imperative to neither continue nor increase our reckless use of nuclear power as an electricity source. ”

by Linda Pentz Gunter, Beyond Nuclear International

source with photos and links

Challenges ahead for debris removal at Fukushima — NHK World

” This year will mark the 7th anniversary of the nuclear accident at the Fukushima Daiichi plant that occurred in March, 2011. The plant’s operator is hoping to eventually remove fuel debris from the damaged reactors.

Fuel debris is a mixture of melted nuclear fuel and broken reactor parts. Removing the debris is considered to be the biggest hurdle to the decommissioning of the reactors.

Last year, Tokyo Electric Power Company, or TEPCO, investigated the inside of the containment vessels of 3 reactors and confirmed, for the first time, the existence of lumps that are believed to be fuel debris in the No.3 reactor.

TEPCO plans to conduct a fresh probe of the No.2 reactor this month to confirm whether a mass on the floor under the reactor, observed last year, is actually fuel debris.

The government and TEPCO aim to begin removing debris in 2021. They are planning to determine which reactor to start with, and how to conduct the procedure, during fiscal 2019.

Workers will try this year to figure out which details need to be considered in order to make the decision.

Removing the debris requires thorough safety measures. For example, radioactive materials must be prevented from spreading and workers must be protected from exposure to radiation.

This autumn, the operator also plans to start removing spent nuclear fuel rods from the storage pool of the No.3 reactor building. ”

by NHK World

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Fears of another Fukushima as Tepco plans to restart world’s biggest nuclear plant — The Guardian

” If a single structure can define a community, for the 90,000 residents of Kashiwazaki town and the neighbouring village of Kariwa, it is the sprawling nuclear power plant that has dominated the coastal landscape for more than 40 years.

When all seven of its reactors are in operation, Kashiwazaki-kariwa generates 8.2m kilowatts of electricity – enough to power 16m households. Occupying 4.2 sq km of land along the Japan Sea coast, it is the biggest nuclear power plant in the world.

But today, the reactors at Kashiwazaki-kariwa are idle. The plant in Niigata prefecture, about 140 miles (225km) north-west of the capital, is the nuclear industry’s highest-profile casualty of the nationwide atomic shutdown that followed the March 2011 triple meltdown at Fukushima Daiichi.

The company at the centre of the disaster has encountered anger over its failure to prevent the catastrophe, its treatment of tens of thousands of evacuated residents and its haphazard attempts to clean up its atomic mess.

Now, the same utility, Tokyo Electric Power [Tepco], is attempting to banish its Fukushima demons with a push to restart two reactors at Kashiwazaki-kariwa, one of its three nuclear plants. Only then, it says, can it generate the profits it needs to fund the decommissioning of Fukushima Daiichi and win back the public trust it lost in the wake of the meltdown.

This week, Japan’s nuclear regulation authority gave its formal approval for Tepco to restart the Kashiwazaki-kariwa’s No. 6 and 7 reactors – the same type of boiling-water reactors that suffered meltdowns at Fukushima Daiichi.

After a month of public hearings, the nuclear regulation authority concluded that Tepco was fit to run a nuclear power plant and said the two reactors met the stricter safety standards introduced after the 2011 disaster.

Just before that decision, Tepco gave the Guardian an exclusive tour of what it claims will be the safest nuclear plant in the world.

Now, as on the day of the triple disaster that brought widespread destruction to Japan’s northeast coast, Kashiwazaki-kariwa has the look of a working nuclear plant. Just over 1,000 Tepco staff and 5,000-6,000 contract workers provide the manpower behind a post-Fukushima safety retrofit that is projected to cost 680 billion yen ($6.1bn).

They have built a 15-metre-high seawall that, according to Tepco, can withstand the biggest tsunami waves. In the event of a meltdown, special vents would keep 99.9% of released radioactive particles out of the atmosphere, and corium shields would block molten fuel from breaching the reactors’ primary containment vessels. Autocatalytic recombiners have been installed to prevent a repeat of the hydrogen explosions that rocked four of Fukushima Daiichi’s reactors.

Other parts of the sprawling complex are home to fleets of emergency vehicles, water cannon, back-up power generators, and a hilltop reservoir whose 20,000 tonnes of water will be drawn to cool reactors in the event of a catastrophic meltdown.

“As the operator responsible for the Fukushima accident, we’re committed to learning lessons, revisiting what went wrong and implementing what we learned here at Kashiwazaki-kariwa, says the plant’s chief, Chikashi Shitara. “We are always looking at ways to improve safety.

“Because of our experience at Fukushima, we’re committed to not making the same mistakes again – to make the safety regime even stronger. That’s what we have to explain to members of the public.”

‘This is no place for a nuclear power plant’

The public, however, is far from convinced. Last year, the people of Niigata prefecture registered their opposition to the utility’s plans by electing Ryuichi Yoneyama, an anti-nuclear candidate, as governor. Exit polls showed that 73% of voters opposed restarting the plant, with just 27% in favor.

Yoneyama has said that he won’t make a decision on the restarts, scheduled for spring 2019, until a newly formed committee has completed its report into the causes and consequences of the Fukushima disaster – a process that could take at least three years.

For many residents, the plant’s location renders expensive safety improvements irrelevant. “Geologically speaking, this is no place for a nuclear power plant,” says Kazuyuki Takemoto, a retired local councillor and a lifelong anti-nuclear activist.

Takemoto cites instability caused by the presence of underground oil and gas deposits in the area, and evidence that the ground on which Tepco’s seawall stands is prone to liquefaction in the event of a major earthquake.

Local critics have pointed to the chaos that could result from attempting to evacuate the 420,000 people who live within a 30km radius of Kashiwazaki-kariwa. “That’s more people than lived near Fukushima, plus we get very heavy snowfall here, which would make evacuating everyone impossible,” Takemoto adds. “The situation would be far worse than it was in Fukushima.”

Adding to their concerns are the presence of seismic faults in and around the site, which sustained minor damage during a magnitude-6.6 offshore earthquake in 2007. Two active faults – defined by nuclear regulators as one that has moved any time within the last 400,000 years – run beneath reactor No. 1.

But for Tepco, a return to nuclear power generation is a matter of financial necessity, with the utility standing to gain up to ¥200 billion in annual profits by restarting the two reactors at Kashiwazaki-Kariwa.

The bill for decommissioning Fukushima Daiichi, decontaminating neighbourhoods and compensating residents affected by the meltdown could reach 21.5tr yen [$191bn], according to government estimates. That is on top of the money the firm is spending on importing expensive fossil fuels to fill the vacuum left by the nuclear shutdown.

Earlier this year, the Japan Centre for Economic Research said the total cost of the four-decade Fukushima cleanup – including the disposal of radioactive waste from the plant’s three damaged reactors – could soar to between 50-70tr yen.

“As Tepco’s president and our general business plan have made clear, restarting the reactors here is very important to us as a company,” says Shitara.

Much is at stake, too, for Japan’s prime minister, Shinzo Abe, who has put an ambitious return to nuclear power generation at the centre of his energy policy. His government wants nuclear to provide about 20 percent Japan’s electricity by 2030 – a move that would require the restart of about 30 reactors.

Of the country’s 48 operable reactors, only four are currently online. Several others have passed stringent new safety tests introduced in the wake of Fukushima, but restarts have encountered strong local opposition.

As part of the restart process, people across Japan were recently invited to submit their opinions on the Kashiwazaki-kariwa restart and Tepco’s suitability as a nuclear operator.

Kiyoto Ishikawa, from the plant’s public relations department, insists Tepco has learned the lessons of Fukushima. “Before 3-11 we were arrogant and had stopped improving safety,” he said. “The earthquake was a wake-up call. We now know that improving safety is a continuous process.”

The firm’s assurances were dismissed by Yukiko Kondo, a Kariwa resident, who said the loss of state subsidies if the plant were to remain permanently idle was a sacrifice worth making if it meant giving local people peace of mind.

“Tepco caused the 2011 accident, so there is no way I would ever support restarting nuclear reactors here,” she said. “They kept telling us that Fukushima Daiichi was perfectly safe – and look what happened.” ”

by Justin McCurry, The Guardian

source with internal links

Kansai Electric to scrap two reactors in latest blow for Japan’s nuclear sector — Intelligencer

” TOKYO (Reuters) – Kansai Electric Power Co said on Friday it will decommission two 38-year-old reactors at its Ohi nuclear plant as Japan’s electricity industry struggles to cope with new safety standards imposed after the 2011 Fukushima disaster.

The widely expected announcement brings to 14 the number of reactors being scrapped since the meltdowns at the Fukushima Daiichi plant. More than six years on, Japan is still turning away from nuclear power in the face of technical problems, public opposition, court challenges and unfavorable economics.

Most of Japan’s reactors remain shut, with only four operating, while they undergo relicensing processes in a bit to meet new standards set after the Fukushima crisis highlighted shortcomings in regulation.

Kansai Electric will now scrap the No. 1 and No. 2 reactors at the Ohi plant, some 86 kilometers (53 miles) from Osaka, western Japan, where the utility is based. Shut since 2011, the reactors have capacity of 1,175 megawatts each, began operations in 1979 and were near the end of their standard operating life of 40 years.

A Kansai Electric spokeswoman said that costs in meeting the new safety standards were not a factor behind the decision, but technical difficulties were.

“The containment vessels of these reactors are smaller than other reactors in Japan, and a need to beef up the walls to meet the standards would make the work zones even more cramped, making it difficult for prompt repairs in case of troubles,” the spokeswoman said.

The move means Japan is likely to soon be eclipsed by China as the third biggest nuclear power sector in the world – by reactor numbers – after the United States and France.

Japan now has 42 reactors, including the two to be decommissioned at Ohi, compared with 38 in China, which has nearly 20 more under construction, while the U.S. and France have 99 and 58 respectively, according to the International Energy Agency.

Kansai Electric was the most reliant on nuclear energy among Japan’s atomic operators, using reactors for nearly half of its electricity generation before the disaster at the Fukushima nuclear plant in 2011, when reactors melted down following a giant earthquake and tsunami. Two other reactors at the Ohi site remain closed.

While Prime Minister Shinzo Abe’s government is keen to restore a power source that provided about a third of electricity supply before the Fukushima crisis, Japan’s public remains deeply skeptical over industry assurances on safety.

Anti-nuclear campaigners and residents are increasingly using courts to block restarts and push for plants to close.

A Japanese court last week ordered Shikoku Electric Power Co not to restart one of its reactors, overturning a lower court decision in the first instance of a higher court blocking the operation of nuclear plant.

Residents have lodged injunctions against most nuclear plants across Japan. ”

Reporting by Aaron Sheldrick and Osamu Tsukimori; Writing by Aaron Sheldrick; Editing by Kenneth Maxwell

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New proposal suggests removing Fukushima plant’s melted nuclear fuel from side — The Mainichi

” A method to remove melted nuclear fuel debris on the bottom of the containment vessels of Fukushima No. 1 Nuclear Power Plant’s first, second and third reactors from the side was proposed by the Nuclear Damage Compensation and Decommissioning Facilitation Corporation (NDF) on July 31.

Hajimu Yamana, head of the NDF, which is tasked with considering how to remove fuel debris from the reactors, for the first time explained the organization’s specific method proposal to the heads of local governments at a countermeasures for the decommissioning and handling of the contaminated water council meeting held in Iwaki, Fukushima Prefecture.

The method would focus on prioritizing the removal of debris from the bottom of the vessels from the side, using robotic arms and other remote devices while flushing water over the debris. However, ways to block radiation and countermeasures against the scattering of airborne radioactive dust still remain unsolved. The central government and Tokyo Electric Power Co. (TEPCO) plan to finalize their policy to remove the debris and amend the decommission schedule in September.

In all three of the reactors, contaminated water has collected at the bottom of the containment vessels. The NDF had previously considered a “flooding method” that would fill the containment vessels completely with water to block radiation from leaking. However, measures to repair the containment vessels and prevent leakage of the radioactive water would be difficult, so the plan was put aside for having “too many issues.” “

by The Mainichi

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