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

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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

Regulator urges Tepco to release treated radioactive water from damaged Fukushima No. 1 nuclear plant into the sea — The Japan Times

” A decision should be made sometime this year over whether to release into the sea water containing radioactive tritium from the crisis-hit Fukushima No. 1 nuclear plant, the chief of Japan’s nuclear regulator said Thursday, emphasizing it would pose no danger to human health.

“We will face a new challenge if a decision (about the release) is not made this year,” Nuclear Regulation Authority Chairman Toyoshi Fuketa told Naraha Mayor Yukiei Matsumoto, referring to the more than 1 million tons of coolant water and groundwater that has accumulated at the crippled facility. Naraha is located close to the Fukushima No.1 plant.

Fuketa said releasing the water into the sea after dilution is the only solution, saying “it is scientifically clear that there will be no impact on marine products or to the environment.”

Currently, Fukushima plant operator Tokyo Electric Power Company Holdings Inc. regularly filters contaminated coolant water and ground water from the damaged plant. The processed water is stored in hundreds of water tanks set up within the plant’s compound.

Dangerous radioactive materials are removed during filtration, but tritium — which is difficult to separate from water but relatively harmless to human health — remains.

“(Tepco) has been building new tanks, but it will eventually run out of land,” an NRA official later told The Japan Times.

With limited storage space for water tanks, observers warn that tritium could start leaking from the Fukushima plant.

The nuclear regulator’s chief underlined the need for the government and Tepco to make a decision quickly, saying, “It will take two or three years to prepare for the water’s release into the sea.”

At other nuclear power plants, water containing tritium is routinely dumped into the sea after it is diluted. The regulator has been calling for the release of the water after diluting it to a density lower than standards set by law.

According to the NRA, an average pressured-water reactor for commercial use in Japan usually dumps 60 trillion becquerels of tritium a year into the sea.

Local fishermen are, however, worried about the negative impact from the water discharge — in particular the effect of groundless rumors regarding the safety of marine life near the Fukushima plant. In the face of their opposition, Tepco has not yet reached a decision on how to deal with the stored water.

At the Fukushima plant contaminated water is building up partly because groundwater is seeping into the reactor buildings and mixing with water that has been made radioactive in the process of cooling the damaged reactors.

According to the NRA, there were 650 water tanks within the compound at the Fukushima No. 1 plant as of last month.

The density of tritium in the water ranges from 1 million to 5 million becquerels per liter. Legal restrictions require a nuclear power plant to dump tritium-tainted water after diluting it to 60,000 becquerels per liter, according to the NRA.

On March 11, 2011, tsunami inundated the six-reactor plant, which is located on ground 10 meters above sea level, and flooded its power supply facilities.

Reactor cooling systems were crippled and the Nos. 1 to 3 reactors suffered fuel meltdowns in the world’s worst nuclear catastrophe since the 1986 Chernobyl disaster. ”

by Kyodo, The Japan Times

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