NRA: Ice wall effects ‘limited’ at Fukushima nuclear plant — The Asahi Shimbun

” Citing “limited, if any effects,” the Nuclear Regulation Authority said a highly touted “frozen soil wall” should be relegated to a secondary role in reducing contaminated groundwater at the Fukushima No. 1 nuclear plant.

The government spent 34.5 billion yen ($292 million) to build the underground ice wall to prevent groundwater from mixing with radioactive water in four reactor buildings at the crippled plant.

But the NRA, Japan’s nuclear watchdog, concluded on Dec. 26 that the wall has been ineffective in diverting the water away from the buildings. It said that despite the low rainfall over the past several months, the amount of groundwater pumped up through wells outside the frozen wall on the seaside is still well above the reduction target.

It urged the plant operator, Tokyo Electric Power Co., to tackle the groundwater problem primarily with pumps, not the ice wall.

In response, TEPCO at the meeting said that by next autumn, it will double its capacity to pump up groundwater from the current 800 tons a day.

About 400 tons of groundwater enters the damaged reactor buildings each day and mixes with highly radioactive water used to cool melted nuclear fuel.

The ice wall project, compiled by the industry ministry in May 2013, was seen as a fundamental solution to this problem that has hampered TEPCO’s cleanup efforts since the triple meltdown in March 2011.

Some 1,568 frozen ducts were inserted 30 meters deep into the ground to circulate a liquid at 30 degrees below zero. The freezing process was supposed to have created a solid wall of ice that could block the groundwater.

TEPCO began freezing the wall on the seaside in March. It announced in the middle of October that the temperature at all measuring points in that area was below zero.

Before the frozen wall project, TEPCO had to pump up about 300 tons of contaminated water a day. The daily volume dropped to about 130 tons in recent weeks, but it was still well beyond the target of 70 tons.

Still, TEPCO boasted about the effectiveness of the ice wall at the meeting with the NRA on Dec. 26, saying, “We are seeing certain results.”

The NRA, however, said the results are limited at best.

Toyoshi Fuketa, an NRA commissioner, already warned TEPCO in October that it cannot expect the ice wall to be highly effective in containing the groundwater.

“Pumping up groundwater through wells should be the main player because it can reliably control the groundwater level,” Fuketa said at that time. “The ice wall will play a supporting role.”

That sentiment was echoed at the Dec. 26 meeting.

However, the NRA approved the utility’s plan to begin freezing dirt for a wall on the mountain side of the nuclear plant.

The NRA was previously concerned about risks posed by the new ice wall. If it totally blocked groundwater from the mountain side, the water level within the frozen soil near the reactors could become too low, allowing highly contaminated water inside the reactor buildings to flow out more rapidly.

The NRA urged TEPCO to delay work on the mountain side until the ice wall on the seaside portion proved effective.

But it reversed its stance, saying a sharp drop in the groundwater level is unlikely based on the ineffectiveness of the existing ice wall.

“The frozen wall on the mountain side will not be able to block groundwater because the wall on the seaside was also unable to do so,” Fuketa said. “It will not be very dangerous to freeze the wall on the mountain side as long as the work is carried out carefully.”

TEPCO will start the work to freeze the ducts at five sections as early as next year.

Masashi Kamon, professor emeritus of geotechniques at Kyoto University, expressed skepticism about continuing the ice wall project without a full scrutiny of the underground conditions.

“Soil around the tunnels for underground pipes must be hard to freeze,” he said. “TEPCO should find out the conditions of the very bottom of the ice wall by drilling at least one section. It is questionable to continue with the project without a review.” ”

by Kohei Tomida

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Fukushima radiation detected in Tillamook Bay, Gold Beach — K5

” For the first time, seaborne radiation from Japan’s Fukushima nuclear disaster has been detected on the West Coast of the United States.

Cesium-134, the so-called fingerprint of Fukushima, was measured in seawater samples taken from Tillamook Bay and Gold Beach in Oregon, researchers from the Woods Hole Oceanographic Institution are reporting.

Because of its short half-life, cesium-134 can only have come from Fukushima.

Also for the first time, cesium-134 has been detected in a Canadian salmon, the Fukushima InFORM project, led by University of Victoria chemical oceanographer Jay Cullen, is reporting.

In both cases, levels are extremely low, the researchers said, and don’t pose a danger to humans or the environment.

Massive amounts of contaminated water were released from the crippled nuclear plant following a 9.0 magnitude earthquake and tsunami in March 2011. More radiation was released to the air, then fell to the sea.

Woods Hole chemical oceanographer Ken Buesseler runs a crowd-funded, citizen science seawater sampling project that has tracked the radiation plume as it slowly makes its way across the Pacific Ocean.

The Oregon samples, marking the first time cesium-134 has been detected on U.S. shores, were taken in January and February of 2016 and later analyzed. They each measured 0.3 becquerels per cubic meter of cesium-134.

Buesseler’s team previously had found the isotope in a sample of seawater taken from a dock on Vancouver Island, B.C., marking its landfall in North America.

Meanwhile, in Canada, Cullen leads the InFORM project to assess radiological risks to that country’s oceans following the nuclear disaster. It is a partnership of a dozen academic, government and non-profit organizations, including Woods Hole.

Last month, the group reported that a single sockeye salmon, sampled from Okanagan Lake in the summer of 2015, had tested positive for cesium-134.

The level was more than 1,000 times lower than the action level set by Health Canada, and is no significant risk to consumers, Cullen said.

Buesseler’s most recent samples off the West Coast also are showing higher-than background levels of cesium-137, another Fukushima isotope that already is present in the world’s oceans because of nuclear testing in the 1950s and 1960s.

Those results will become more important in tracking the radiation plume, Buesseler said, because the short half-life of cesium-134 makes it harder to detect as time goes on.

Cesium-134 has a half-life of two years, meaning it’s down to a fraction of what it was five years ago, he said. Cesium-137 has a 30-year half-life.

A recent InFORM analysis of Buesseler’s data concluded that concentrations of cesium-137 have increased considerably in the central northeast Pacific, although they still are at levels that pose no concern.

“It appears that the plume has spread throughout this vast area from Alaska to California,” the scientists wrote.

They estimated that the plume is moving toward the coast at roughly twice the speed of a garden snail. Radiation levels have not yet peaked.

“As the contamination plume progresses towards our coast we expect levels closer to shore to increase over the coming year,” Cullen said.

Even that peak won’t be a health concern, Buesseler said. But the models will help scientists model ocean currents in the future.

That could prove important if there is another disaster or accident at the Fukushima plant, which houses more than a thousand huge steel tanks of contaminated water and where hundreds of tons of molten fuel remain inside the reactors.

In a worst-case scenario, the fuel would melt through steel-reinforced concrete containment vessels into the ground, uncontrollably spreading radiation into the surrounding soil and groundwater and eventually into the sea.

“That’s the type of thing where people are still concerned, as am I, about what could happen,” Buesseler said.

Scientists now know it would take four to five years for any further contamination from the plant to reach the West Coast. ”

by Tracy Loew

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Japan tsunami highlights Fukushima nuclear plant vulnerability — Voice of America

” The 7.4 magnitude earthquake and small tsunami that struck Japan’s northeast coast on Tuesday morning tested the sea wall constructed around the Fukushima nuclear plant, that was the site of one of the worst nuclear catastrophes in history.

The earthquake hit at early morning and was centered off the coast of the Fukushima Prefecture at a depth of about 10 kilometers, according to the Japan Meteorological Agency.

The Pacific Tsunami Warning Center said the first wave of the tsunami was measured at 90 centimeters, then the waves died down. About an hour and a half after the earthquake there was also 1.4 meter wave that was large enough to cause some flooding.

Japanese television showed tsunami waves flowing up rivers in some areas, and some fishing boats were overturned in the port of Higashi-Matsushima.

Reports of injuries and damage from Tuesday’s earthquake and tsunami were minimal. Residents in the region evacuated to higher ground after tsunami warning sirens sounded in the early morning and many ships moved out to sea to ride out the incoming ocean surge.

Magnitude

While the Japan Meteorological Agency calculated the earthquake’s magnitude at 7.4, the U.S. Geological Survey (USGS) measured it to be a 6.9 quake.

Tuesday’s earthquake was much less powerful than the 9.0 earthquake that struck the same region in March of 2011, generating enormous tsunami waves, some as high a 40 meters, that killed close to 20,000 people and caused the meltdown of the Fukushima Nuclear Power Plant, the worst nuclear crisis since Chernobyl a quarter of a century earlier.

Geophysicist Rafael Abreu with the USGS Earthquake Information Center says a one magnitude point rise on the seismic scale equals a 32 time increase in destructive power released during an earthquake.

“The magnitude of a 9.0 quake is an earthquake that released 32×32, over 1,000 times more energy then the quake that we had today,” said Abreu.

Fukushima

The Fukushima nuclear reactors that were damaged during the 2011 meltdown have been since shut down, but the Tokyo Electric Power Company (TEPCO) still maintains cooling systems to prevent the spent nuclear material from overheating and spewing radioactive waste into the air and ocean.

Naohiro Masuda, head of TEPCO’s Decommissioning Unit, said on Tuesday a one-meter tsunami was observed from two Fukushima nuclear power plants but precautions were taken to prevent a possible breech.

“With regards to Fukushima plant No. 1, it appears to be there is no problem inthe plant, but we proactively stopped operation of the contaminated water discharge system with a judgement that it could be problematic if it (radioactive water) leaks out,” he said.

In 2015, TEPCO competed a 780-meter coastal sea wall around the heavily damaged reactor buildings of the Fukushima No. 1 plant to reduce the amount of contaminated water flowing into the ocean. During the worst of the crisis it was leaking 400 tons of radioactive water a day.

An ice wall has also been constructed to reduce the amount of water flowing into the nuclear plant from the nearby mountains.

Kendra Olrich, a Senior Global Energy Campaigner with the environmentalist organization Greenpeace in Japan, said the sea wall fared relatively well this time but Tuesday’s earthquake illustrates that Japan is too geologically unstable to safely operate nuclear power plants.

“All of these earthquakes continue to highlight the absurdity of having nuclear power in a country that is sitting on the Pacific ring of fire,” she said.

Inside the damaged Fukushima plants, efforts are still underway to remove the molten nuclear core and move the highly radioactive materials to a safer storage facility.

Olrich said radioactive contamination that seeped into the surrounding forests during the tsunami five years ago continue to pose a danger to public health and safety. She is also critical of government plans to lift evacuation orders in affected areas next year that would end TEPCO’s obligation to provide compensation, at the cost of potentially exposing residents to increased risks. ”

by Brian Padden; contributions from Youmi Kim

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Why the water cooling system at Fukushima nuclear plant stopped — Business Insider Australia

” The cooling system at the Fukushima nuclear plant is back online.

Earlier this morning, officials were “trying to establish what’s gone wrong” at the Fukushima nuclear plant.

A 7.3 magnitude earthquake struck 67km off the coast of Japan this morning, and tsunamis have been recorded hitting the east coast.

Officials at the plant originally said they had noted no irregularities with the plant, but at 9.15am AEDT, news came through that the plant’s water cooling system “appears to have stopped”, although the operator of the plant said there was no immediate danger.

At 10.05am AEDT, NHK confirmed the cooling equipment for the spent nuclear fuel pool in the reactor number three of Tepco’s Fukushima number two power plant wasn’t working.

An official spokesperson from operator Tepco says the earthquake “shook” water in the cooling tanks temporarily, leading to a decline in levels.

That triggered a warning and the plant’s cooling systems stopped, possibly as a precaution to stop them in turn overheating.

The cooling pumps have now resumed and the water in the towers is cooling again.

In the two hours the pumps were off, the spent rods heated the water from 27.7C at 6.10am to 29.5C. However, officials say that was “within safe range” and the water would have to heat for a week to reach a dangerous level.

The plant currently stores around 1000 tanks of contaminated water, and no leakage has been noted yet.

Chief cabinet secretary Yoshihide Suga says, “We have been informed that there is no immediate risk of radiation leaks or rise in the temperatures (of the cooling pool).” ”

by Peter Farquhar

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Fukushima radiation in the Pacific (revisited) — Triple Pundit

by RP Siegel

” My recent post on the spread of radiation stemming from the Fukushima nuclear accident drew quite a few questioning comments. Specifically the article suggested that radiation from the accident was drifting across the Pacific at levels high enough to cause alarm. It turns out such cause for alarm was exaggerated, though there is still reason to be concerned. I appreciate the feedback. I acknowledge that I relied on sources with which I was unfamiliar and posted some information that has been shown to be incorrect. I apologize.

To all who publish online, beware. Bad news travels fast. It gives credence to the old saying, “A lie can travel halfway around the world while the truth is still putting its pants on.” This is especially true on the Internet. I truly hope no one was harmed by this information. Now begins the task of earning back your trust which, though hard-earned, can be quickly lost.

I think the best way to start is to post a revised story on what is actually happening in the waters around Fukushima, Japan, as well as those farther afield.

Let’s start by addressing the points made in the original story.

For starters the initial source, PeakOil, used a bogus NOAA graphic to sensationalize the story, having carefully scrubbed out the legend showing that the colors actually represented wave heights at the peak of the tsunami, not radiation levels as the site would have you believe. I checked this image out, noticed this and chose not to use it in my post. Still, I continued to take the central thrust of the story as true.

Several people went to the generally reliable Snopes site to question the story and found confirmation of their suspicions. The blatant misuse of the NOAA chart is clearly called and tossed into the trash where it belongs. An interesting thing about the Snopes post, however, is that while the site prominently displays a text clipping stating that, “each day 300 tons of radioactive waste seeps into the ocean,” it never specifically addresses that claim.

I dug further and found that number actually comes from a quote by Yushi Yoneyama, an official with the Japanese Ministry of Economy, Trade and Industry, which oversees energy policy as quoted in Reuters (generally considered unassailable) and elsewhere. In 2013, Yoneyama said, “We think that the volume of water [leaking into the Pacific] is about 300 tonnes a day.” Of course, anyone could be wrong, but who am I to question Reuters or a Japanese government official? I don’t.

That’s not to say Japanese government officials, or officers of TEPCO, can always be counted on to tell the truth, but their interest has generally been to minimize the extent of the damage, not to embellish it.

As for that amount of leakage, that’s equivalent to about 90,000 gallons of radioactive water. That sounds like quite a bit. But compared to the volume of the Pacific Ocean, it’s not a lot at all. Still, when that much leaks out each day, over the course of a year, it adds up to 33 million gallons. And it’s been five years now.

Even today, TEPCO only acknowledges that radioactive water threatens to flood out of the plant and into the ocean. The company denied, until recently, that any water leaked from the plant at all, even when fish contaminated with high levels of radiation were found near the plant by independent researchers from the University of Tokyo, raising major concerns for local fishermen.

The story regarding radiation reaching the Canadian West Coast, which claimed levels of iodine-131 were 300 times background levels, was recently updated with an editor’s statement that the original figures were incorrect.

Reports of a wildlife biologist (Alexandra Morton) pulling hundreds of herring out of the waters off British Columbia with blood coming out of their eyes and gills have not been discredited. However, there is no evidence linking this observation directly to radiation from Fukushima or anywhere else.

The claim that radiation levels found in tuna off the Oregon coast had tripled also appears to be legitimate. However, those levels are still substantially below what would be considered a health threat.

Having sorted through that, I would summarize as follows: Contaminated water continues to enter to ocean from the Fukushima site in significant volume. Traces of radiation have been found in various locations around the Pacific. It also appears that the levels detected at this time do not indicate any immediate threat to humans outside of Japan. That being said, our knowledge of the long-term impacts of these types of radiation on the oceans, and on ourselves, is far from complete.

Upon review, most of the statements in the original piece were in fact true, but I acknowledge the overall sense was that of an exaggerated cause for concern. What this shows is how easily a group of facts taken out of context can become a convincing story — a lesson for all of us. Putting it on the Internet is like putting a match to a dry grassland.

What is far less clear is what the actual levels are and where they can be found. What makes writing about this issue so difficult, and even dangerous, is the combination of two things: It’s a frightening subject, and there is very little solid information being made available.

In my efforts to bring in some more solid facts, I reached out to Greenpeace, which is monitoring the situation carefully. The group sent me some additional information in a press release with links to reports published outside the U.S.

Greenpeace’s famed ship, the Rainbow Warrior, went out to sample the waters around Fukushima in February of this year with former Japanese Prime Minister Mr. Naoto Kan onboard. What they found was that radiation in the seabed off Fukushima “is hundreds of times above pre-2011 levels.” They also found levels in nearby rivers that were “up to 200 times higher than ocean sediment.”

Expressing concern, Ai Kashiwagi, energy campaigner for Greenpeace Japan, said: “These river samples were taken in areas where the Abe government is stating it is safe for people to live. But the results show there is no return to normal after this nuclear catastrophe.”

The areas sampled include the Niida River in Minami Soma, where readings measured as high as 29,800 becquerels per kilogram (Bq/kg) for radio-cesium. (For those new to the subject, a becquerel is a derived unit that measures radioactivity.) More samples taken at the estuary of the Abukuma River in Miyagi prefecture, more than 90 kilometers north of the Fukushima Daiichi plant, found levels in sediment as high as 6,500 Bq/kg. To put that in perspective, recorded levels in the seabed near the plant before the disaster were 0.65 Bq/kg.

Kendra Ulrich, senior global energy campaigner for Greenpeace Japan, explained: “The sheer size of the Pacific Ocean combined with powerful complex currents means the largest single release of radioactivity into the marine environment has led to the widespread dispersal of contamination.”

Greenpeace expressed concern that the order scheduled to allow people to return to these areas next March “cannot be permitted to stand.” The group claims that “these ecosystems cannot simply be decontaminated.”

Greenpeace’s report, which came out in July of this year, concludes by saying the impact of the accident will persist for “decades to centuries.”

So, while we have not yet seen the global-scale consequences some predicted, the situation is indeed bad and getting worse. TEPCO continues to build steel tanks at the rate of three per week, to house a great deal of contaminated groundwater while awaiting decontamination. But according to this PBS documentary, the company will run out of room for more tanks sometime next year. The gravity-fed water filtration system has been effective in removing most contaminants, except for tritium. Tritium is a relatively weak radionuclide with a half-life of 12.5 years, which means it will take about 100 years to fully break down.

The molten nuclear cores in reactors still remain in three reactors. And the site will not be fully stabilized until those are removed. But the radioactivity level in those reactors is far too high for people to enter. TEPCO plans to develop robots to go in and retrieve the molten fuel. The company says that retrieval is estimated to begin in 2020.

In closing, while the level of concern suggested in the prior piece was overstated, I maintain that the situation at Fukushima is far from resolved and that it remains a serious concern, particularly in Japan. I further maintain that any plans to continue expanding nuclear power must include an in-depth review of what has happened in Fukushima, with the understanding that this story is far from over. ”

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Study: Possible water problem at storage sites in Fukushima — The Asahi Shimbun

” Bags of radiation-contaminated soil could be sinking into the ground at temporary storage sites in Fukushima Prefecture, allowing water to accumulate within instead of flowing to outside tanks for testing, the Board of Audit said.

No confirmation has been made that the ground at the sites is actually sinking or if contaminated water has pooled inside. But Board of Audit officials are asking the Environment Ministry to consider additional safety measures if signs indicate that this is actually occurring.

The board’s study focused on 34 of the 106 temporary storage sites that the Environment Ministry set up for soil removed through decontamination work after the disaster in March 2011 unfolded at the Fukushima No. 1 nuclear power plant.

Construction of the storage sites started in 2012, and the transfer of contaminated soil to these facilities was completed in 2015.

The temporary storage sites were designed to have a slight mound on the ground in the center to allow water from the bags to flow down into surrounding collection tanks for periodic measurements of radiation levels.

Internal Environment Ministry guidelines called for this setup at storage sites containing bags that are not waterproof.

The Board of Audit studied 34 temporary storage sites where the bags are not waterproof. These bags were piled five deep or higher at those sites.

The study showed that at 31 of the sites, the weight of the bags may have not only flattened the mound in the center, but it also could have created an indent in the ground where the leaking water could accumulate.

If the water does not flow to the tanks, it will be difficult to determine the radiation levels.

The study also noted that the foundations at the sites were soft to begin with and may be unable to support the bags of soil. The sinking phenomenon could worsen as time passes.

The Environment Ministry played down the risk of the water contaminating areas around the storage facilities.

“Even if the ground has sunk, the structure is designed so water does not leak outside the site,” a ministry official said. “Eventually, the water should collect in the tanks. We will make every effort to oversee the sites as well as use waterproof bags as much as possible.”

A total of 4.16 billion yen ($40 million) was spent to construct the 31 temporary storage sites.

The Environment Ministry designed the temporary storage sites under the precondition they would be used for only three years and then removed. For that reason, measures were not taken to strengthen the foundations to prevent the ground from sinking, even if soft farmland was chosen for a site.

The plan is to eventually return the land where the temporary storage sites have been built to its original state and return it to the landowners.

However, the Board of Audit’s study adds another concern for residents, many of whom had opposed construction of the temporary storage sites in their neighborhoods.

Toshio Sato, 68, has evacuated to Fukushima city from his home in Iitate village, where four of the possible problem storage sites are located.

“There are some people who want to resume growing rice once they return home,” Sato said. “If water is accumulating, there is the possibility it could unexpectedly overflow into surrounding areas. The concerns just seem to emerge one after another.”

The government plans to lift the evacuation order for a large part of Iitate in March 2017. ”

by Kosuke Tauchi, Shoko Rikimaru, Kenji Izawa and Akifumi Nagahashi

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