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

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Prime Minister Abe uses the Tokyo Olympics as snake oil cure for the Fukushima Daiichi nuclear meltdowns — Fairewinds Energy Education

” As we prepare for the eighth remembrance of the March 11, 2011 earthquake, tsunami and triple meltdowns at Fukushima Daiichi, Fairewinds is ever mindful of what is currently happening in Japan.

There has never been a roadmap for Japan to extricate itself from the radioactive multi-headed serpentine Hydra curse that has been created in an underfunded, unsuccessful attempt to clean-up the ongoing spread of migrating radioactivity from Fukushima. Rather than focus its attention on mitigating the radioactive exposure to Japan’s civilians, the government of Japan has sought instead to redirect world attention to the 2020 Olympics scheduled to take place in Tokyo.

Truthfully, a situation as overwhelming as Fukushima can exist in every location in the world that uses nuclear power to produce electricity. The triple meltdowns at Fukushima Daiichi are the worst industrial catastrophe that humankind has ever created.

Prior to Fukushima, the atomic power industry never envisioned a disaster of this magnitude anywhere in the world. Worldwide, the proponents and operators of nuclear power plants still are not taking adequate steps to protect against disasters of the magnitude of Fukushima!

Parts of Japan are being permanently destroyed by the migrating radioactivity that has been ignored, not removed, and subsequent ocean and land contamination is expanding and destroying once pristine farmlands and villages. For reference in the US and other countries, Fukushima Prefecture is approximately the size of the State of Connecticut. Think about it, how would an entire State – its woods, rivers, and valleys, eradicate radioactive contamination?

Let’s begin with the reactors and site itself. There was a triple meltdown in 2011, yet Tokyo Electric banned the use of the word “meltdown” in any of its communications with Japanese civilians. Now we know that in the first week after the tsunami, each molten radioactive core melted through its six-inch-thick steel reactor, burned and chemically reacted with the concrete underneath, and all are now lying in direct contact with groundwater. Aside from a few grainy pictures of those cores showing burn holes in the reactors, nothing has been done to remove the cores and to prevent further contamination of the groundwater. I have witnessed schemes including a mining operation to bore under the reactors and an underground train to collect the molten masses, but those schemes are decades from fruition. The government of Japan claims that the Fukushima site will be entirely cleaned and decommissioned in less than forty years, a date that will definitely slip AFTER the 2020 Tokyo Olympics are held, and one that is scientifically impossible since some radioactive isotopes will be spread across the Fukushima site and surrounding landscape for 300 years and others for 250,000 years.

Fukushima’s radioactive reactor cores have been in direct contact with groundwater for the last eight years, and then that highly toxic radioactive water enters the Pacific Ocean. When the disaster struck TEPCO wanted to build an ice-wall to prevent the spread of the contamination, which I knew would fail. I advocated immediately surrounding the reactors with a trench filled with zeolite, a chemical used to absorb radiation at other atomic facilities.

“The problem with freezing the soil is that as soon as you get an earthquake, you lose power and then your ice turns to mush and you’re stuck.” Gundersen, who has visited the Fukushima power plant in the past, said a better solution would be to dig a two-meter wide trench down to bedrock level and fill it with a material called zeolite: a volcanic material that comes from Mother Nature.

“It’s incredibly good at filtering radioactive isotopes. So whatever is inside the fence will stay inside and whatever is outside the fence would be clean,” said Gundersen, who estimates the price tag for such a project would be around $10 billion.

TEPCO’s ice wall has not eliminated radiation from spreading via groundwater. How will Fukushima’s owner TEPCO and the government of Japan successfully clean and mitigate the damage caused by the three atomic reactors that each lost their fuel to a meltdown? These problems were never anticipated in Japan where these reactors were built and operated or in the United States where the Fukushima nuclear plants were engineered and designed and the parts were manufactured.

Since the meltdowns in 2011, Fairewinds notified the world that the recovery plans for the proposed cleanup would be almost untenable, calling it a ‘long slog’. From the very beginning, I made it clear that “the nuclear disaster is underfunded and lacks transparency, causing the public to remain in the dark.” Sadly, eight years later, nothing has changed.

In February 2012 when I spoke to the press at the Tokyo Foreign Correspondents Press Club, the government’s recovery from the radiation released by Fukushima has never been about protecting the people of Japan. It was clear in the immediate aftermath of the world’s largest atomic power disaster and still today, the government of Japan is focused on protecting the financial interests of the nuclear power corporations in Japan so they may build new reactors as well as continue to operate the old ones. Clearly, the steps taken by the government of Japan shows that the survival of the electric generating corporations like Hitachi, Toshiba, Tokyo Electric and others are more important to the Abe Government that the survival of 160,000 evacuees and the future of the food supply emanating from Japan’s agriculture and aquaculture.

Evacuees in Japan are being forced to move back to their community and their homes that remain radioactively contaminated by the Fukushima Daiichi detonations and meltdowns. The government of Japan and the alleged global regulator, the International Atomic Energy Agency (IAEA) – which was chartered by the United Nations (UN) to both promote and regulate atomic power generation – have raised the allowable public radiation level more than 20-times what it originally was rather than return to land to the condition it once was.

An exposé released in early February 2019 in The Washington Post said that, 

For six years, Namie was deemed unsafe after a multiple-reactor meltdown at the Fukushima Daiichi Nuclear Power Plant following a 2011 earthquake and tsunami. In March 2017, the government lifted its evacuation order for the center of Namie. But hardly anyone has ventured back. Its people are scattered and divided. Families are split. The sense of community is coming apart…

As we at Fairewinds Energy Education have repeatedly said since the tragic 2011 meltdowns, understanding why the fate of the 160,000 evacuees from the toxic Fukushima landscape does not matter to the government of Japan, one must simply follow the money trail back to the corporations producing Japan’s electricity. As Fairewinds has noted from its personal experience, and what The Washington Post and the people of Japan clearly understand is that these meltdown refugees are simply pawns in a much bigger issue of money and politics. According to The Washington Post article,

For the people of Namie and other towns near the Fukushima plant, the pain is sharpened by the way the Japanese government is trying to move beyond the tragedy, to use the 2020 Tokyo Olympics as a symbol of hope and recovery, a sign that life can return to normal after a disaster of this magnitude…. Its charm offensive is also tied up with efforts to restart the country’s nuclear-power industry, one of the world’s most extensive networks of atomic power generation. [Emphasis Added].

Six Olympic softball games and a baseball game will be staged in Fukushima, the prefecture’s bustling and radiation-free capital city, and the Olympic torch relay will start from here.

To determine whether or not Olympic athletes might be affected by fallout emanating from the disaster site, Dr. Marco Kaltofen and I were sponsored by Fairewinds Energy Education to look at Olympic venues during the fall of 2017. We took simple dirt and dust samples along the Olympic torch route as well as inside Fukushima’s Olympic stadium and as far away as Tokyo. When the Olympic torch route and Olympic stadium samples were tested, we found samples of dirt in Fukushima’s Olympic Baseball Stadium that were highly radioactive, registering 6,000 Bq/kg of Cesium, which is 3,000 times more radioactive than dirt in the US. We also found that simple parking lot radiation levels were 50-times higher there than here in the US.

Thirty of the dirt and fine dust samples that I took on my last two trips to Japan in February and March 2016 and September 2017 were analyzed at WPI (Worchester Polytechnic Institute. The WPI laboratory analysis are detailed in the report entitled: Measuring Radioactivity in Soil and Dust Samples from Japan, T. Pham, S. Franca and S. Nguyen, Worchester Polytechnic Institute, which found that:

With the upcoming XXXII Olympiad in 2020 hosted by Japan, it is necessary to look into the radioactivity of Olympic venues as well as tourist attractions in the host cities… Since thousands of athletes and millions of visitors are traveling to Japan for the Olympics, there has been widespread concern from the international community about radiation exposure. Therefore, it is important to investigate the extent of radioactive fallout from the Fukushima Dai-ichi incident…

The measured results showed a much higher activity of Cesium-137 in the proposed torch route compared to other areas. Overall, the further away from the Fukushima Dai-ichi Nuclear Power Plant, the lower the radioactivity. The activity of Cesium-137 in Tokyo, the furthest site from the plant, was the lowest when compared to the other sites. Therefore, the activity of Cesium-137 in Tokyo sample was used as the baseline to qualitatively estimate the human exposure to radiation.

.… At the Azuma Sports Park, the soil and dust samples yielded a range of 78.1 Bq/kg to 6176.0 Bq/kg. This particular Olympic venue is around 90 km from the Nuclear Power Plant. The other sites that are closer to the Nuclear Power Plant like the tourist route, proposed torch route, and non-Olympic samples have higher amounts due to the close proximity to ground zero of the disaster.

 … the proposed torch route samples had the highest mean radioactivity due to their close proximity to the plant. Based on the measurement, we estimated qualitatively that the radiation exposure of people living near the Azuma Sports Park area was 20.7 times higher than that of people living in Tokyo. The main tourist and proposed torch routes had radiation exposure of 24.6 and 60.6 times higher, respectively, than in Tokyo…. Olympic officials should consider using the results of this project to decide whether the radioactivity level at the proposed torch route and the Olympic venues are within acceptable level.

On a more personal note, I witnessed first-hand the ongoing radioactive devastation in and around the Namie area like that detailed in The Washington Post’s revealing and factual essay. During the two weeks I spent in and around Namie in September 2017 I took six short videos showing what the devastation looks and feels like up close. These short iPhone videos total less than 5-minutes of run time. I was on my own, without a videographer, so these short films probably lack the professional quality viewers may usually associate with Fairewinds, however, they do convey the very palpable feeling of gloom and emptiness pervading the ghost towns I visited. I am sharing the first three short videos in today’s blog. We will be releasing a Part 2 of this Fukushima update, which will feature another three short films.

Longtime Friends of Fairewinds may remember that back in 2011, Prime Minister Noda (he was between the ousted Prime Minister Naoto Kan, who was PM when the Fukushima Meltdowns occurred and today’s Prime Minister Abe), claimed that the three melted down Fukushima reactors were in ‘cold shutdown’, which they were not, in order to lay the groundwork for Japan’s Olympic bid. Noda claimed “… we can consider the accident contained”. Fairewinds compared Noda’s “cold shutdown” hypocrisy to former President George Bush crowing about “Mission Accomplished” in Iraq. Sadly, what we said in 2011 still rings true today:

Is the Japanese government and the IAEA protecting the nuclear industry and not the people of Japan by claiming that Fukushima is stable when it is not? Fairewinds’ chief engineer Arnie Gundersen outlines major inconsistencies and double-speak by the IAEA, Japanese Government, and TEPCO claiming that the Fukushima accident is over. Dynamic versus static equilibrium, escalated dose exposures to the Japanese children and nuclear workers, and the blending of radioactive materials with non-contaminated material and spreading this contaminated ash throughout Japan are only a small part of this ongoing nuclear tragedy.

Later in 2013, Japan pressed the International Olympic Committee and bribed some of its members to accept the Olympics in 2020 according to an Associated Press article February 18, 2019 by Journalist Haruka Nuga.

Members of the JOC executive board are up for re-election this summer. There is speculation Takeda…[ Japanese Olympic Committee President Tsunekazu Takeda, who is being investigated for his part in an alleged bribery scandal] will not run, or could be replaced. French investigators believe he may have helped Tokyo win the 2020 Olympics in a vote by the International Olympic Committee.

Takeda has been JOC president since 2001. He is also a powerful IOC member and the head of its marketing commission. He has not stepped aside from either position while the IOC’s ethics committee investigates.

…French authorities suspect that about $2 million paid by the Tokyo bid committee — headed by Takeda — to a Singapore consulting company, Black Tidings, found its way to some IOC members in 2013 when Tokyo won the vote over bids from Istanbul and Madrid… Takeda last month acknowledged he signed off on the payments but denied corruption allegations. An internal report in 2016 by the Japanese Olympic Committee essentially cleared Takeda of wrongdoing.

Tokyo is spending at least $20 billion to organize the Olympics. Games costs are difficult to track, but the city of Tokyo appears to be picking up at least half the bill.

Much of Japan’s focus has been to show that the Fukushima area is safe and has recovered from a 2011 earthquake, tsunami, and the meltdowns at three nuclear reactors. [Emphasis Added]

Here is what I said in a video on Fairewinds website in 2013, when the original Tokyo Olympic announcement was made.

I think hosting the Olympics in 2020 is an attempt by the Japanese to change the topic. I don’t think people around the world are going to care until 2020 approaches. There is a seven-year window for the Japanese government to work to make Tokyo a showcase for the entire world to view. I think the Japanese government wanted to host the Olympics to improve the morale of the people of Japan after the Fukushima Daiichi accident. Unfortunately, it’s taking people’s attention off of the true cost of the accident, in terms of both money and public health.

Placing the Olympics in Tokyo was and still is a ploy to minimize the consequences of the Fukushima Daiichi meltdowns and to take the public’s attention away from a pressing emergency that still needs resolution for the health and safety of the people of Japan.

Fairewinds Energy Education will keep you informed with Part 2, at fairewinds.org. ”

by Arnie Gundersen, edited by Maggie Gundersen, Fairewinds Energy Education

Thank you, Fairewinds, for your diligent reporting. 🙂

source with photos and videos

Fukushima’a other big problem: A Million tons of radioactive water — Wired

” The tsunami-driven seawater that engulfed Japan’s Fukushima Daiichi nuclear plant has long since receded. But plant officials are still struggling to cope with another dangerous flood: the enormous amounts of radioactive water the crippled facility generates each day. More than 1 million tons of radiation-laced water is already being kept on-site in an ever-expanding forest of hundreds of hulking steel tanks—and so far, there’s no plan to deal with them.

The earthquake and tsunami that hammered Fukushima on March 11, 2011 triggered meltdowns in three of its six reactors. That left messes of intensely radioactive fuel somewhere loose in the reactor buildings—though no one knows exactly where. What is known, however, is that every day, as much as much as 150 tons of groundwater percolates into the reactors through cracks in their foundations, becoming contaminated with radioactive isotopes in the process.

To keep that water from leaking into the ground or the Pacific, Tepco, the giant utility that owns the plant, pumps it out and runs it through a massive filtering system housed in a building the size of a small aircraft hangar. Inside are arrays of seven-foot tall stainless steel tubes, filled with sand grain-like particles that perform a process called ion exchange. The particles grab on to ions of cesium, strontium, and other dangerous isotopes in the water, making room for them by spitting out sodium. The highly toxic sludge created as a byproduct is stored elsewhere on the site in thousands of sealed canisters.

This technology has improved since the catastrophe. The first filtering systems, installed just weeks after the disaster by California-based Kurion Inc. (which has since been bought by Veolia, a French resource management company), only caught cesium, a strong gamma radiation emitter that makes it the most dangerous of the isotopes in the water. The tubes in those arrays were filled with highly modified grains of naturally occurring volcanic minerals called zeolites. By 2013, the company developed entirely artificial particles—a form of titano silicate—that also grab strontium.

The filters, however, don’t catch tritium, a radioactive isotope of hydrogen. That’s a much trickier task. Cesium and strontium atoms go into solution with the water, like sugar in tea; but tritium can bond with oxygen just like regular hydrogen, rendering the water molecules themselves radioactive. “It’s one thing to separate cesium from water, but how do you separate water from water?” asks John Raymont, Kurion’s founder and now president of Veolia’s nuclear solutions group. The company claims to have developed a system that can do the job, but Tepco has so far balked at the multi-billion dollar cost.

So for now, the tritiated water is pumped into a steadily growing collection of tanks. There are already hundreds of them, and Tepco has to start building a new one every four days.

Tepco has at least reduced the water’s inflow. As much as 400 tons per day was gushing in just a couple of years ago. In an effort to keep the groundwater from getting in, Tepco has built a network of pumps, and in 2016 installed an underground “ice wall”—a $300 million subterranean fence of 30-yard-long rods through which tons of sub-zero brine is pumped, freezing the surrounding earth. All of which helps, but hasn’t solved the problem.

Tritium is far less dangerous than cesium—it emits a weaker, lower-energy form of radiation. Still, all that tritiated water can’t just be stored indefinitely. “Some of those tanks and pipes will eventually fail. It’s inevitable,” says Dale Klein, a former head of the US Nuclear Regulatory Commission who has been consulting with Tepco since the early days following the disaster. (In fact, hundreds of tons of water leaked out of the tanks in 2013 and 2014, sparking an international outcry. Tepco has since improved their design.)

Klein, among others, believes that the concentrations of tritium are low enough that the water can safely be released into the sea. “They should dilute and dispose of it,” he says. “It would be better to have a controlled release than an accidental one.”

But the notion of dumping tons of radioactive water into the ocean is understandably a tough sell. Whatever faith the Japanese public had left in Tepco took a further beating in the first couple of years after the meltdowns, when several investigations forced the company to acknowledge they had underreported the amount of radiation released during and after the disaster. Japan’s fishing industry raises a ruckus whenever the idea of dumping the tritiated water is broached; they already have to contend with import restrictions imposed by neighboring countries worried about eating contaminated fish. Japan’s neighbors including China, Korea, and Taiwan have also objected.

For now, all Tepco can do is keep building tanks, and hope that someone comes up with a solution before they run out of room—or the next earthquake hits. “

by Vince Beiser, Wired

source with internal links and photo

Fukushima nuclear plant: Tsunami wall could have avoided disaster but boss scrapped the plan, employee testifies — Newsweek

” A worker for the plant involved the 2011 Fukushima nuclear disaster said in a Japanese court Wednesday that his former boss was warned that a massive tsunami could strike the site, but delayed measures to build a protective wall to prevent it.

An unnamed employee of the Tokyo Electric Power Company (TEPCO) that owns the ruined Fukushima Daiichi or No.1, Nuclear Power Plant testified during a trial this week that a 2008 safety test showed an earthquake could cause a tsunami as high as 52 feet capable of pounding the coastal facility, according to The Asahi Shimbun. The company was initially set to build a seawall, but the employee told the court that former TEPCO Vice President Sakae Muto suddenly dismissed the idea.

The potentially catastrophic scenario was brought up again during a meeting on March 7, 2011, compelling shocked regulators to again recommend a wall to shield the facility, The Japan Times reported. But it was too late already: A magnitude 9.0 earthquake and tsunami struck only four days later on March 11, 2011, leaving up to 18,500 people dead or missing and destroying the facility.

Three out of the six nuclear reactors at the Fukushima No.1 plant suffered devastating meltdowns. Muto, along with former TEPCO Chairman Tsunehisa Katsumata and former TEPCO Vice President Ichiro Takekuro were indicted in February 2016 and are facing trial for suspected professional negligence resulting in death or injury after the worst nuclear disaster since the Chernobyl incident in 1986.

The multi-billion dollar effort to recover the site is far past schedule and over budget, but the TEPCO has claimed some recent successes. Six years after the disaster, the melted nuclear fuel was finally founded at the bottom of the partially submerged reactors. The site was so radioactive, even the robots previously sent it could not traverse the deadly core.

Efforts to retrieve the fuel, however, have been hampered as the $324 million ice wall that penetrated 100 feet into the earth failed to stop groundwater from leaking into the site, as Reuters reported last month. In fact, the amount of groundwater seeping into the facility may have increased since the highly-anticipated ice wall was installed last August, amounting to the latest setback in a cleanup process already beset by seemingly endless complications and miscalculations.

Removing this water adds to an already growing storage crisis on the site. TEPCO deliberately added water to cool off the plant’s damaged reactors. After coming in contact with the plant, the coolant water and groundwater became tainted with a substance known as tritium, a byproduct of the nuclear process notoriously difficult to filter out of water. TEPCO has accumulated over 1 million tons of this tritium-laced water in 650 giant tanks, according to The Japan Times, and is urging the government to let the company begin dumping it into the ocean.

Some locals have protested this, however. While tritium was a natural byproduct of the nuclear process that experts have described as harmless in smaller doses and was dumped into oceans worldwide, Fukushima activists and fishermen have argued that dumping tritium, even in small quantities, would further hurt the reputation of the region, still synonymous with nuclear disaster. Nearby China and South Korea are among the nations that still restrict the import of certain products from Japan.

Lingering concerns about radiation have also reportedly kept many of the 160,000 residents that fled Fukushima from returning. Life, nevertheless, has begun to return to some parts of the crisis-stricken prefecture. The town of Okuma announced Wednesday that some citizens would be allowed to stay overnight starting next week for the first time since the March 2011 disaster, Japanese daily The Mainichi Shimbun said. ”

by Tom O’Connor, Newsweek

source with image and internal links

Clearing the radioactive rubble heap that was Fukushima Daiichi, 7 years on — Scientific American

” Seven years after one of the largest earthquakes on record unleashed a massive tsunami and triggered a meltdown at Japan’s Fukushima Daiichi nuclear power plant, officials say they are at last getting a handle on the mammoth task of cleaning the site before it is ultimately dismantled. But the process is still expected to be a long, expensive slog, requiring as-yet untried feats of engineering—and not all the details have yet been worked out.

When the disaster knocked out off- and on-site power supplies on March 11, 2011, three of the cooling systems for the plant’s four reactor units were disabled. This caused the nuclear fuel inside to overheat, leading to a meltdown and hydrogen explosions that spewed out radiation. The plant’s operator, Tokyo Electric Power Co. (TEPCO), responded by cooling the reactors with water, which continues today. Meanwhile thousands of people living in the surrounding area were evacuated and Japan’s other nuclear plants were temporarily shut down.

In the years since the disaster and the immediate effort to stanch the release of radioactive material, officials have been working out how to decontaminate the site without unleashing more radiation into the environment. It will take a complex engineering effort to deal with thousands of fuel rods, along with the mangled debris of the reactors and the water used to cool them. Despite setbacks, that effort is now moving forward in earnest, officials say. “We are still conducting studies on the location of the molten fuel, but despite this we have made the judgment that the units are stable,” says Naohiro Masuda, TEPCO’s chief decommissioning officer for Daiichi.

Completely cleaning up and taking apart the plant could take a generation or more, and comes with a hefty price tag. In 2016 the government increased its cost estimate to about $75.7 billion, part of the overall Fukushima disaster price tag of $202.5 billion. The Japan Center for Economic Research, a private think tank, said the cleanup costs could mount to some $470 billion to $660 billion, however.

Under a government roadmap, TEPCO hopes to finish the job in 30 to 40 years. But some experts say even that could be an underestimate. “In general, estimates of work involving decontamination and disposal of nuclear materials are underestimated by decades,” says Rod Ewing, a professor of nuclear security and geological sciences at Stanford University. “I think that we have to expect that the job will extend beyond the estimated time.”

The considerable time and expense are due to the cleanup being a veritable hydra that involves unprecedented engineering. TEPCO and its many contractors will be focusing on several battlefronts.

Water is being deliberately circulated through each reactor every day to cool the fuel within—but the plant lies on a slope, and water from precipitation keeps flowing into the buildings as well. Workers built an elaborate scrubbing system that removes cesium, strontium and dozens of other radioactive particles from the water; some of it is recirculated into the reactors, and some goes into row upon row of giant tanks at the site. There’s about one million tons of water kept in 1,000 tanks and the volume grows by 100 tons a day, down from 400 tons four years ago.

To keep more water from seeping into the ground and being tainted, more than 90 percent of the site has been paved. A series of drains and underground barriers—including a $325-million* supposedly impermeable “wall” of frozen soil—was also constructed to keep water from flowing into the reactors and the ocean. These have not worked as well as expected, though, especially during typhoons when precipitation spikes, so groundwater continues to be contaminated.

Despite the fact contaminated water was dumped into the sea after the disaster, studies by Japanese and foreign labs have shown radioactive cesium in fish caught in the region has fallen and is now within Japan’s food safety limits. TEPCO will not say when it will decide what to do with all the stored water, because dumping it in the ocean again would invite censure at home and abroad—but there are worries that another powerful quake could cause it to slosh out of the tanks.

Fuel Mop-up

A second major issue at Fukushima is how to handle the fuel¾the melted uranium cores as well as spent and unused fuel rods stored at the reactors. Using robotic probes and 3-D imaging with muons (a type of subatomic particle), workers have found pebbly deposits and debris at various areas inside the primary containment vessels in the three of the plant’s reactor units. These highly radioactive remains are thought to be melted fuel as well as supporting structures. TEPCO has not yet worked out how it can remove the remains, but it wants to start the job in 2021. There are few precedents for the task. Lake Barrett—director of the Three Mile Island nuclear plant during its decommissioning after a partial meltdown at the Middletown, Pa., facility in 1979—says TEPCO will use robots to remotely dig out the melted fuel and store it in canisters on-site before shipping to its final disposal spot. “This is similar to what we did at Three Mile Island, just much larger and with much more sophisticated engineering because their damage is greater than ours was,” Barrett says. “So although the work is technically much more challenging than ours was, Japan has excellent technological capabilities, and worldwide robotic technology has advanced tremendously in the last 30-plus years.”

Shaun Burnie, senior nuclear specialist with Greenpeace Germany, doubts the ambitious cleanup effort can be completed in the time cited, and questions whether the radioactivity can be completely contained. Until TEPCO can verify the conditions of the molten fuel, he says, “there can be no confirmation of what impact and damage the material has had” on the various components of the reactors—and therefore how radiation might leak into the environment in the future.

Although the utility managed to safely remove all 1,533 fuel bundles from the plant’s unit No. 4 reactor by December 2014, it still has to do the same for the hundreds of rods stored at the other three units. This involves clearing rubble, installing shields, dismantling the building roofs, and setting up platforms and special rooftop equipment to remove the rods. Last month a 55-ton dome roof was installed on unit No. 3 to facilitate the safe removal of the 533 fuel bundles that remain in a storage pool there. Whereas removal should begin at No. 3 sometime before April 2019, the fuel at units No. 1 and 2 will not be ready for transfer before 2023, according to TEPCO. And just where all the fuel and other radioactive solid debris on the site will be stored or disposed of long-term has yet to be decided; last month the site’s ninth solid waste storage building, with a capacity of about 61,000 cubic meters, went into operation.

As for what the site itself might look like decades from now, cleanup officials refuse to say. But they are quick to differentiate it from the sarcophagus-style containment of the 1986 Chernobyl catastrophe in the Soviet Union, in what is now Ukraine. Whereas the Chernobyl plant is sealed off and the surrounding area remains off-limits except for brief visits—leaving behind several ghost towns—Japanese officials want as many areas as possible around the Daiichi site to eventually be habitable again.

“To accelerate reconstruction and rebuilding of Fukushima as a region, and the lives of locals, the key is to reduce the mid- and long-term risk,” says Satoru Toyomoto, director for international issues at the Ministry of Economy, Trade and Industry’s Nuclear Accident Response Office. “In that regard, keeping debris on the premises without approval is not an option.” ”

by Tim Hornyak, Scientific American

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Experts: Fukushima must do more to reduce radioactive water — U.S. News

Here is a good article written by Mari Yamaguchi that explains the state of contaminated water at the Fukushima Daiichi plant. Experts say that the ice wall that was built to keep groundwater from coming into the power plant and becoming contaminated with radioactivity is only half effective. A conventional drainage system also collects water from wells dug around the plant and pumps it out before it becomes contaminated. This water is stored in about 1,000 storage tanks near the facility. Read more about the construction, operation and maintenance costs that are coming out of the taxpayer’s pocket.

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