Japan wants to dump nuclear plant’s tainted water. Fishermen fear the worst. — The New York Times

” IWAKI, Japan — The overpowering earthquake and tsunami that ripped through northern Japan in March 2011 took so much from Tatsuo Niitsuma, a commercial fisherman in this coastal city in Fukushima Prefecture.

The tsunami pulverized his fishing boat. It demolished his home. Most devastating of all, it took the life of his daughter.

Now, nearly nine years after the disaster, Mr. Niitsuma, 77, is at risk of losing his entire livelihood, too, as the government considers releasing tainted water from a nuclear power plant destroyed by the tsunami’s waves.

Prime Minister Shinzo Abe’s cabinet and the Tokyo Electric Power Company — the operator of the Fukushima Daiichi plant, where a triple meltdown led to the worst nuclear crisis since Chernobyl — must decide what to do with more than one million tons of contaminated water stored in about 1,000 giant tanks on the plant site.

On Monday, Japan’s Ministry of Economy, Trade and Industry proposed gradually releasing the water into the ocean or allowing it to evaporate, saying a controlled discharge into the sea would “stably dilute and disperse” it. The ministry ruled out alternatives like continuing to store it in tanks or injecting it deep into the ground. Mr. Abe’s cabinet will make the final decision.

The water becomes contaminated as it is pumped through the reactors to cool melted fuel that is still too hot and radioactive to remove. For years, the power company, known as Tepco, said that treatment of the water — which involves sending it through a powerful filtration system to remove most radioactive material — was making it safe to release.

But it is actually more radioactive than the authorities have previously publicized. Officials say that it will be treated again, and that it will then be safe for release.

Regardless of government assurances, if the water is discharged into the sea, it will most likely destroy the livelihoods of hundreds of fishermen like Mr. Niitsuma. Consumers are already worried about the safety of Fukushima seafood, and dumping the water would compound the fears.

It would “kill the industry and take away the life of the boats,” he said. “The fish won’t sell.”

With Fukushima preparing to host baseball games during the Summer Olympics next year, and the plant running out of land on which to build storage tanks, the debate has taken on a sense of urgency.

Until last year, Tepco indicated that with the vast majority of the water, all but one type of radioactive material — tritium, an isotope of hydrogen that experts say poses a relatively low risk to human health — had been removed to levels deemed safe for discharge under Japanese government standards.

But last summer, the power company acknowledged that only about a fifth of the stored water had been effectively treated.

Last month, the Ministry of Economy, Trade and Industry briefed reporters and diplomats about the water stored in Fukushima. More than three-quarters of it, the ministry said, still contains radioactive material other than tritium — and at higher levels than the government considers safe for human health.

The authorities say that in the early years of processing the deluge of water flowing through the reactors, Tepco did not change filters in the decontamination system frequently enough. The company said it would re-treat the water to filter out the bulk of the nuclear particles, making it safe to release into the ocean.

Some experts and local residents say it is difficult to trust such assurances.

“The government and Tepco were hiding the fact that the water was still contaminated,” said Kazuyoshi Satoh, a member of the city assembly in Iwaki.

“Because next year is the Tokyo Olympics, Prime Minister Shinzo Abe wants to present the image that everything is ‘under control,’” said Mr. Satoh, referring to a speech by the Japanese leader to the International Olympic Committee when Tokyo was bidding to host the 2020 Games.

The power company acknowledged that it had not made it easy for the public to get information. The water treatment data “has not been presented in a manner that is easy to understand,” said Ryounosuke Takanori, a Tepco spokesman.

“As long as the water was stored in the tanks, we thought it didn’t matter whether the water” exceeded safety standards for discharge, said Junichi Matsumoto, a general manager in the Fukushima Daiichi decontamination and decommissioning office.

Mr. Niitsuma, for whom fishing is not just a livelihood but also a balm against grief over the loss of his daughter, said he thought both Tepco and the government needed to come clean.

“I want them to see the reality squarely and disclose information fully,” said Mr. Niitsuma, who goes out alone on his two-ton boat at dawn three times a week.

His wife, Yoko, waits on the pier. On a recent morning, she helped drag the nets out of the boat and dump squirming octopus, flounder and a few red gurnard into buckets that the couple loaded onto a small flatbed truck to drive to a warehouse where wholesalers bid on the fish.

Mrs. Niitsuma said she didn’t believe the government was looking out for Fukushima’s fishing families. “They are talking about discharging the water,” she said. “That itself means they are not thinking about us.”

The question of whether the water could be decontaminated to safe levels is a matter of degree, scientists say.

If the water is processed so that the only radioactive materials that remain are low levels of tritium, said Kazuya Idemitsu, a professor of nuclear engineering at Kyushu University, releasing it into the ocean would be “the best solution in terms of cost and safety.”

Mr. Idemitsu added that functioning nuclear plants around the world release diluted water containing tritium into the ocean.

Some scientists said they would need proof before believing that the Fukushima water was treated to safe levels.

“I want to see the numbers after they’ve removed these additional radionuclides,” said Ken Buesseler, a senior scientist in marine chemistry and geochemistry at Woods Hole Oceanographic Institution in Massachusetts. “Then, and only then, can I make a judgment on the quality of the rationale for releasing it or the consequences of releasing it.”

Government officials argue that the water is not so much a scientific problem as a perceptual one.

“If the water is discharged into the ocean, the price of seafood products may drop, or consumers won’t want to buy them at all,” said Shuji Okuda, director for decommissioning and contaminated water management at the economy and trade ministry. “So even though there is no scientific evidence that the water is dangerous, we are worried about the effects.”

More than 20 countries still have import restrictions on Japanese seafood and other agricultural products that were imposed after the 2011 disaster. Earlier this year, the European Union lifted its ban on some products.

In Fukushima, the fishing industry brings only about 15 percent of its pre-disaster catch levels to market. Every haul is sampled and screened in labs run by Fukushima’s prefectural government and the fisheries cooperative.

According to the co-op, the central government currently prohibits the sale of only one species, a rare type of skate.

Tadaaki Sawada, the co-op’s division chief, said that if the water was discharged, buyers would be unlikely to believe government safety assurances.

“Most people can live without fully understanding the details of radioactivity,” Mr. Sawada said. “They can just say ‘because I don’t understand fully, I won’t buy Fukushima fish.’”

In the prefecture, where thousands of residents never returned after evacuating, those who have come back harbor lingering doubts.

“In the corner of my mind, I wonder if it is safe or not,” Keiko Nagayama, 65, said as she browsed at a seafood freezer in Naraha, a hamlet in the original 12-mile exclusion zone around the Fukushima plant.

A government evacuation order was lifted in 2015. Although flounder and Pacific saury from Iwaki were on sale, Ms. Nagayama chose flounder from Hokkaido, in far northern Japan.

Yukiei Matsumoto, Naraha’s mayor, declined to offer an opinion on the idea of water disposal from the nuclear plant.

“Nuclear policy is central government policy,” Mr. Matsumoto said. “The contaminated water is their business.”

Naraha is one of several Fukushima towns where the central government has spent heavily to draw people back to their communities.

Just 3,877 people — a little over half of the original population — have returned. Tokyo has devoted large sums to subsidize a new school, a strip mall and a new arena that cost 4 billion yen, or about $37 million.

On a recent afternoon, a smattering of people worked out in the gym, while just one man used the 25-meter swimming pool in the arena complex.

Yukari Nakamura, 33, a local artist, had been hired to paint murals on the walls and windows. Her husband, Yuuki, and two young children were the only family in a spacious playroom.

Ms. Nakamura said a Fukushima label on fish gave her pause. “My heart aches to reject the seafood, and I feel such pain not being able to recommend it,” she said, tearing up. “I don’t want to hurt the fishermen who caught it, but it is so complicated.” “

by Motoko Rich and Makiko Inoue

source with photos and internal links

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

Japan will have to dump radioactive water into Pacific, minister says — The Guardian

” The operator of the ruined Fukushima Daiichi nuclear power plant will have to dump huge quantities of contaminated water from the site directly into the Pacific Ocean, Japan’s environment minister has said – a move that would enrage local fishermen.

More than 1 million tonnes of contaminated water has accumulated at the plant since it was struck by a tsunami in March 2011, triggering a triple meltdown that forced the evacuation of tens of thousands of residents.

Tokyo Electric Power (Tepco) has struggled to deal with the buildup of groundwater, which becomes contaminated when it mixes with water used to prevent the three damaged reactor cores from melting.

Tepco has attempted to remove most radionuclides from the excess water, but the technology does not exist to rid the water of tritium, a radioactive isotope of hydrogen. Coastal nuclear plants commonly dump water that contains tritium into the ocean. It occurs in minute amounts in nature.

Tepco admitted last year that the water in its tanks still contained contaminants beside tritium.

Currently, more than 1m tonnes of contaminated water is held in almost 1,000 tanks at the Fukushima Daiichi site, but the utility has warned that it will run out of tank space by the summer of 2022.

“The only option will be to drain it into the sea and dilute it,” Yoshiaki Harada told a news briefing in Tokyo on Tuesday. “The whole of the government will discuss this, but I would like to offer my simple opinion.”

No decision on how to dispose of the water will be made until the government has received a report from a panel of experts. Other options include vaporising the liquid or storing it on land for an extended period.

Harada did not say how much water would need to be discharged into the ocean.

One recent study by Hiroshi Miyano, who heads a committee studying the decommissioning of Fukushima Daiichi at the Atomic Energy Society of Japan, said it could take 17 years to discharge the treated water after it has been diluted to reduce radioactive substances to levels that meet the plant’s safety standards.

Any decision to dispose of the waste water into the sea would anger local fishermen, who have spent the past eight years rebuilding their industry.

Nearby South Korea has also voiced concern over the impact it would have on the reputation of its own seafood.

Last month, Seoul summoned a senior Japanese embassy official to explain how Fukushima Daiichi’s waste water would be dealt with.

Ties between the north-east Asian nations are already at a low ebb following a compensation dispute over Koreans forced to work in Japanese factories during the second world war.

The government spent 34.5 bn yen (£260m) to build a frozen underground wall to prevent groundwater reaching the three damaged reactor buildings. The wall, however, has succeeded only in reducing the flow of groundwater from about 500 tonnes a day to about 100 tonnes a day.

Japan has come under renewed pressure to address the contaminated water problem before Tokyo hosts the Olympics and Paralympics next summer.

Six years ago during the city’s bid for the games, the prime minister, Shinzo Abe, assured the international community that the situation was “under control”.

by The Guardian

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Eight years on, water woes threaten Fukushima cleanup — Reuters

” OKUMA, Japan (Reuters) – Eight years after the Fukushima nuclear crisis, a fresh obstacle threatens to undermine the massive clean-up: 1 million tons of contaminated water must be stored, possibly for years, at the power plant.

Last year, Tokyo Electric Power Co said a system meant to purify contaminated water had failed to remove dangerous radioactive contaminants.

That means most of that water – stored in 1,000 tanks around the plant – will need to be reprocessed before it is released into the ocean, the most likely scenario for disposal.

Reprocessing could take nearly two years and divert personnel and energy from dismantling the tsunami-wrecked reactors, a project that will take up to 40 years.

It is unclear how much that would delay decommissioning. But any delay could be pricey; the government estimated in 2016 that the total cost of plant dismantling, decontamination of affected areas, and compensation, would amount to 21.5 trillion yen ($192.5 billion), roughly 20 percent of the country’s annual budget.

Tepco is already running out of space to store treated water. And should another big quake strike, experts say tanks could crack, unleashing tainted liquid and washing highly radioactive debris into the ocean.

Fishermen struggling to win back the confidence of consumers are vehemently opposed to releasing reprocessed water – deemed largely harmless by Japan’s nuclear watchdog, the Nuclear Regulation Authority (NRA) – into the ocean.

“That would destroy what we’ve been building over the past eight years,” said Tetsu Nozaki, head of the Fukushima Prefectural Federation of Fisheries Co-operative Associations. Last year’s catch was just 15 percent of pre-crisis levels, partly because of consumer reluctance to eat fish caught off Fukushima.

SLOW PROGRESS

On a visit to the wrecked Fukushima Dai-ichi plant last month, huge cranes hovered over the four reactor buildings that hug the coast. Workers could be seen atop the No. 3 building getting equipment ready to lift spent fuel rods out of a storage pool, a process that could start next month.

In most areas around the plant, workers no longer need to wear face masks and full body suits to protect against radiation. Only the reactor buildings or other restricted areas require special equipment.

Fanning out across the plant’s property are enough tanks to fill 400 Olympic-sized swimming pools. Machines called Advanced Liquid Processing Systems, or ALPS, had treated the water inside them.

Tepco said the equipment could remove all radionuclides except tritium, a relatively harmless hydrogen isotope that is hard to separate from water. Tritium-laced water is released into the environment at nuclear sites around the world.

But after newspaper reports last year questioned the effectiveness of ALPS-processed water, Tepco acknowledged that strontium-90 and other radioactive elements remained in many of the tanks.

Tepco said the problems occurred because absorbent materials in the equipment had not been changed frequently enough.

The utility has promised to re-purify the water if the government decides that releasing it into the ocean is the best solution. It is the cheapest of five options a government task force considered in 2016; others included evaporation and burial.

Tepco and the government are now waiting for another panel of experts to issue recommendations. The head of the panel declined an interview request. No deadline has been set.

NRA chief Toyoshi Fuketa believes ocean release after dilution is the only feasible way to handle the water problem. He has warned that postponing the decision indefinitely could derail the decommissioning project.

STORING INDEFINITELY

Another option is to store the water for decades in enormous tanks normally used for crude oil. The tanks have been tested for durability, said Yasuro Kawai, a plant engineer and a member of Citizens’ Commission on Nuclear Energy, a group advocating abandoning nuclear energy.

Each tank holds 100,000 tons, so 10 such tanks could store the roughly 1 million tons of water processed by ALPS so far, he said.

The commission proposes holding the tritium-laced water, which has a half life of 12.3 years, in tanks for 123 years. After that, it will be one thousandth as radioactive as it was when it went into storage.

Although experts caution that tanks would be vulnerable to major quakes, Japan’s trade and industry minister, Hiroshige Seko, said the committee would consider them anyway.

“Long-term storage … has an upside as radiation levels come down while it is in storage. But there is a risk of leakage,” Seko told Reuters. “It is difficult to hold the water indefinitely, so the panel will also look into how it should be disposed of eventually.”

Space is also a problem, said Akira Ono, Tepco’s chief decommissioning officer. By 2020, the utility will expand tank storage capacity by 10 percent to 1.37 million tons, and about 95 percent of total capacity will probably be used by the end of that year, he said.

“Tanks are now being built on flat, elevated spots in stable locations,” Ono said. But such ideal space is getting scarce, he added.

Many local residents hope Tepco will just keep storing the water. If it does get released into the ocean, “everyone would sink into depression,” said fishing trawler captain Koichi Matsumoto.

Fukushima was once popular with surfers. But young people in the area do not go surfing any more because they’ve been repeatedly warned about suspected radioactivity in the water, said surf shop owner Yuichiro Kobayashi.

Releasing treated water from the plant “could end up chasing the next generation of children away from the sea as well,” he said.

Ono says dealing with contaminated water is one of many complex issues involved in decommissioning.

A year ago, when he took over leading the effort, it felt like the project had just “entered the trailhead,” he said. “Now, it feels like we’re really starting to climb.” ”

Reporting by Kiyoshi Takenaka; Editing by Malcolm Foster and Gerry Doyle, Reuters

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Fukushima’s underground ice wall keeps nuclear radiation at bay — CNET

” The intricate network of small metal pipes, capped off by six-foot-high metal scaffolding, shouldn’t stand out amid the numerous pieces of industrial equipment littered throughout the Fukushima Daiichi Nuclear Power Plant. After all, it’s a power plant.

I take a closer look, and notice spheres of ice perched upon the smaller pipes, which line the center of the structure. The facility sits at the water’s edge, and there’s a brisk breeze blowing through.

But not that brisk.

It turns out, coolant is running through the pipes, freezing the soil below and creating an impermeable ice wall that’s nearly 100 feet deep and a mile long, encircling the reactors.

It’s like a smaller-scale subterranean version of the Wall in Game of Thrones, but instead of keeping out White Walkers and wights, this line of defense keeps in a far more realistic danger: radioactive contaminants from melted-down reactors that threaten to spill into the water by Fukushima Daiichi.

Daiichi is the site of the worst nuclear disaster, which happened after an earthquake hit on March 11, 2011, triggering a tsunami that devastated the facility. Two 50-foot-high waves knocked out the power generators that were keeping three of the six reactors’ fuel rods cool, triggering explosions and meltdowns that forced more than 160,000 people to flee their homes. Many of them still haven’t returned.

I came to Fukushima to check out the robots tasked with the near-impossible task of cleaning up Fukushima Daiichi. While here, I encountered this underground wall of ice.

The structure, which cost roughly $300 million, paid for by public funds, serves as critical protection, defending the Fukushima area from one of the most radioactive hotspots in the world. While Tokyo Electric Power Co., also known as Tepco, struggles to find a way to remove radioactive material from the facility – a process the government estimates could take more than four decades – the more immediate concern is what to do with the contaminated water leaking out from the facility.

One of the solutions has been to put up (down?) this underground ice wall, which prevents much of the surrounding groundwater from getting in. And while the practice of freezing soil to create a barrier has been around for more than 150 years, the magnitude of the application that stands before me is quite literally groundbreaking.

“Nobody has taken on a project of this scale,” Hideki Yagi, general manager of Tepco’s Nuclear Power Communications Unit, tells me through an interpreter.

Ice cold

While the term “ice wall” has a colorful ring to it, engineers use the more academic-sounding term Artificial Ground Freezing. The technique came out of France in 1862 as a way to help with the construction of mine shafts before German engineer F.H. Poetsch patented it. Since then, it’s been used to aid in building underwater tunnels or vertical shafts, as well as to cut off groundwater or redirect contaminated materials.

At Fukushima, my eyes follow the path of the pipes, which stretch around the reactor building. A Tepco employee tells me that a calcium chloride solution is pumped down through a smaller inner pipe, and circulated back up a large outer pipe.

The coolant brings down the temperature of each pipe to -30 degrees Celsius, or -22 degrees Fahrenheit, and the pipes are spaced about three feet apart. The cold emanating from each one hardens the soil around it.

The point of the ice wall is to keep the groundwater that runs down from the mountains to the west from entering Fukushima Daiichi and mixing with the toxic water leaking out of the Unit 1, 2 and 3 reactors. That is,  keep the clean water on the outside of the wall, while the contaminated water stays inside.

Tepco and manufacturing partners, such as Toshiba and Mitsubishi, are working on robots to identify and determine how to clear out the radioactive materials in each of the reactors’ primary containment vessels, essentially the heart of each facility.

Until then, they need a way to slow or stop the flow of water into the facility. At least initially, Tepco wasn’t even sure if the project was feasible.

“One of the challenges was how they would inject the pipes into the earth at such a deep level without impacting the other operations around it, and whether it would work,” Yagi says.

With the wall in place, Tepco says it has been able to reduce the level of contaminated water generated from Daiichi. But a Reuters report in March 2018 found that the wall still let a fair amount of clean water in, adding to the volume of toxic water the company needs to deal with. Tepco, however, says it’s been effective in reducing the volume.

“We know this is not the end of our effort,” says a company spokesman. “We will be continuously working hard to reduce the amount of  generation of contaminated water.”

The leaky bucket

Imagine a leaky bucket that constantly needs to be filled with water. At the same time, the water from the leak needs to be collected and stored. And there’s no end in sight to this cycle.

That essentially is the problem that Tepco faces at Daiichi. The fuel rods stored in the three radioactive units constantly have to be cooled with fresh water, but leaks mean the company needs to be vigilant about keeping the tainted liquid from getting out of the facility’s grounds.

Since the accident nearly eight years ago, Tepco has collected 1.1 million tons of contaminated water in 900 tanks stored on the grounds at Daiichi. The company estimates it has enough space in the 37.7-million-square-foot facility to house an additional 270,000 tons of water, which means it would run out sometime in 2020.

“We’re conscious of the fact that we can’t keep storing more and more water,” Kenji Abe, a spokesman for Tepco’s decommissioning and decontamination unit, says through an interpreter.

Tepco has worked on several solutions to decrease the level of contaminated water generated by the facility. The company has switched from tanks sealed with bolts to welded tanks, which offer greater storage capacity and less risk of leaks. There’s a steel wall by the water to keep the contaminants from flowing into the ocean. Tepco has also covered 96 percent of the surface of most of the facility with concrete, preventing rainwater from seeping in.

Then there’s the ice wall, which has done its share of lowering the amount of contaminated water generated from the facility by keeping out most of the groundwater.

Over the past three and a half years, Tepco has seen the amount of polluted water generated fall by a quarter to just under 3,900 cubic feet of water per day, with occasional spikes during periods of rainfall.

The final element

I’m in full protective gear, including a Tyvek coverall, hardhat and full-face respirator mask, walking through one of three water treatment facilities at Daiichi. I move hastily, trying to keep up with my Tepco guides, when my suit gets snagged on an exposed bolt.

Did the suit rip? My eyes shoot back at my photographer and widen with fear. This is usually the part in an outbreak movie that dooms a key character. I look down and see the suit is still intact, and breathe a sigh of relief.

It turns out, I didn’t need to panic. The facility, called the Advanced Liquid Processing System, isn’t radioactive, although it’s designed to remove radioactive elements from the collected water. There are three such facilities, which can process a total of 70,630 cubic feet of water a day.

So far, treatment technology from partner companies like Kurion and Sarry have enabled Tepco to remove 62 of the 63 radioactive elements from the water, but one, tritium, remains.

It’s this one element, which is bonded to the water at an atomic level, that means Tepco needs to keep collecting and storing the water.

Lake Barrett, a senior adviser to Tepco who previously served as acting director of the Office of Civilian Radioactive Waste Management at the US Department of Energy, notes that reactors in China and Canada already discharge water with tritium.

“It’s fundamentally safe,” Barrett says.

But organizations such as Greenpeace have called for Tepco to keep storing the water, noting that much of the early batches of treated water far exceed safety limits for radioactive elements.

Given the sensitivities around Fukushima, Tepco must continue to store the water. A spokesman said the company isn’t planning to disperse the water. But it is one option being considered by the Japanese government, which ultimately makes the decision.

“Resolving the issue of the contaminated water is something we haven’t yet reached a final solution on,” Yagi says.

Analyzing the data

Underneath the building housing the restaurant and employee rest area is a water treatment analysis center, a super-clean area that requires us to go through numerous radiation tests and four sets of boot changes.

There are glass beakers containing sea water, groundwater and water from the ALPS facilities. Scientists walk around in silence, moving beakers from one machine to another. A dozen machines in a second room measure the gamma ray levels.

The facility was originally built underground in 2014 because it needed to be on the Daiichi site, but couldn’t be exposed to radiation because of the nature of the tests. The walls are 8 inches thick, with the more sensitive labs hardened with an additional 20 inches. The facility has grown by 16 times over the past four years as it expanded the number of workers and machines.

“No other facility in Japan can handle the amount of data and work we do here,” says a Tepco scientist working at the facility who preferred not to identify himself.

He adds that all of the data is released publicly. “That’s because society demands work with a high level of trust,” he says.

The scientist explains that Japan has set a legal radioactivity limit of 60,000 becquerel per liter of tritium. But the treated water is still at 1.7 million Bq per liter, or roughly 30 times what’s deemed safe.

So, for now, Tepco must continue collecting the water. And the ice wall continues to stand, invisible to onlookers, as one of the most important lines of defense. ”

by Roger Cheng, CNET

source with photos and a video showing how robots have been used to view melted fuel

Local Fury and Health Concerns as Japan plans to dump a million tons of radioactive Fukushima water into ocean — Common Dreams

” In a move that has sparked outrage from local residents and dire health warnings from environmentalists, the Japanese government is reportedly planning to release 1.09 million tons of water from the Fukushima Dai-ichi nuclear plant into the Pacific Ocean despite evidence that it contains “radioactive material well above legally permitted levels.”

While both the Japanese government and Tokyo Electric Power Co. (Tepco)—the company that runs the Fukushima Dai-ichi plant—have claimed that radioactive material in the water has been reduced to undetectable amounts and that only “safe levels of tritium” remain, documents obtained by the London-based Telegraph suggest that the cleaning system being used to decontaminate the water “has consistently failed to eliminate a cocktail of other radioactive elements, including iodine, ruthenium, rhodium, antimony, tellurium, cobalt, and strontium.”

“The government is running out of space to store contaminated water that has come into contact with fuel that escaped from three nuclear reactors after the plant was destroyed in the March 2011 earthquake and tsunami that struck northeast Japan,” the Telegraph reported. “Its plan to release the approximately 1.09 million tons of water currently stored in 900 tanks into the Pacific has triggered a fierce backlash from local residents and environmental organizations, as well as groups in South Korea and Taiwan fearful that radioactivity from the second-worst nuclear disaster in history might wash up on their shores.”

One document the Telegraph obtained from the government body charged with responding to the 2011 Fukushima disaster reportedly indicates that the Japanese government is perfectly aware that the Advanced Liquid Processing System (ALPS) is failing to eliminate radioactive materials from the water stored at the Fukushima site, despite its claims to the contrary.

Last September, the Telegraph notes, “Tepco was forced to admit that around 80 percent of the water stored at the Fukushima site still contains radioactive substances above legal levels after the Ministry of Economy, Trade, and Industry held public hearings in Tokyo and Fukushima at which local residents and fishermen protested against the plans.”

Shaun Burnie, a nuclear specialist with Greenpeace, argued that even so-called “safe” levels of tritium are harmful to humans and marine life.

“Its beta particles inside the human body are more harmful than most X-rays and gamma rays,” Burnie told the Telegraph, adding that there “are major uncertainties over the long-term effects posed by radioactive tritium that is absorbed by marine life and, through the food chain, humans.”

The Japanese government’s reported plans to release the water into the Pacific despite these warnings “cannot be considered an action without risk to the marine environment and human health,” Burnie concluded. ”

by Jake Johnson, Common Dreams

source