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

source

In Fukushima, a bitter legacy of radiation, trauma and fear — Yale Environment 360

” Japan’s Highway 114 may not be the most famous road in the world. It doesn’t have the cachet of Route 66 or the Pan-American Highway. But it does have one claim to fame. It passes through what for the past five years has been one of the most radioactive landscapes on the planet – heading southeast from the Japanese city of Fukushima to the stricken nuclear power plant, Fukushima Daiichi, through the forested mountains where much of the fallout from the meltdown at the plant in March 2011 fell to earth.

It is a largely empty highway now, winding through abandoned villages and past overgrown rice paddy fields. For two days in August, I traveled its length to assess the aftermath of the nuclear disaster in the company of Baba Isao, an assemblyman who represents the town of Namie, located just three miles from the power plant and one of four major towns that remain evacuated.

At times, the radiation levels seemed scarily high – still too high for permanent occupation. But radiation was just the start. More worrying, I discovered, was the psychological and political fallout from the accident. While the radiation – most of it now from caesium-137, a radioactive isotope with a half-life of 30 years – is decaying, dispersing, or being cleaned up, it is far from clear that this wider trauma has yet peaked. Fukushima is going to be in rehab for decades.

I began my journey with Baba, a small bustling man of 72 years, at Kawamata, a town on Highway 114 that is a gateway to the mountains beyond. These mountains are where the fallout was greatest, and the forests that cover most of their slopes have retained the most radioactivity. The mountains make up most of the government-designated “red zone,” where radiation doses exceed 50 millisieverts a year and which are likely to remain uninhabited for many years.

A second “yellow zone” has doses of 20-50 millisieverts, where returning may soon be possible; and a third “green zone,” with less than 20 millisieverts, is deemed safe to live in, and an organized return is under way or planned. Zones are re-categorized as radioactivity decays and hotspots are decontaminated.

To check progress, I took with me a Geiger counter that measured gamma radiation, the main source of radiation for anyone not eating contaminated food.

Beyond Kawamata, the road was largely empty and houses sat abandoned and overgrown. There was no cellphone signal. At first, houses we measured at the roadside had radiation doses equivalent to only around 2 millisieverts per year, a tenth of the government threshold for reoccupation. But within minutes, as we climbed into the mountains, radiation increased as we moved from green to yellow to red zones.

Despite the radiation, wildlife is thriving in the absence of people, Baba said. There are elk, lynx, monkeys, and bears in the mountains. “Nature here is beautiful,” he said, “but we can’t fish or collect bamboo shoots or eat the mountain vegetables that people used to harvest from the forests.”

We stopped by an abandoned gas station in Tsushima, a village in the lee of Mount Hiyama, where wild boar had excavated the soil right by a vending machine that appeared remarkably intact. The bright-red digital display on an official Geiger counter read the equivalent of 21 millisieverts per year, just above the limit for human habitation.

The day after the disaster at the power plant began, 1,400 people from Namie came to Tsushima after being ordered to evacuate. “I was among them,” said Baba. “We had no information. People were just told to come. When we arrived, we went to the village police station and found that the police there were in full protective clothing against the radiation. They said it was a precaution in case they had to go to the power plant, but they had obviously been told that something serious was going on that the population hadn’t been told. That’s when our suspicion about the honesty of the authorities began.”

Tsushima has since become an unofficial shrine to the disaster. In the window of an abandoned shop are posters with bitter, ironic messages, some directed at the nuclear plant’s operator, Tokyo Electric Power: “Thanks to TEPCO, we can shed tears at our temporary housing,” read one. “Thanks to TEPCO, we can play pachinko.” But one, in English, just said, “I shall return.”

Back on Highway 114, a car stopped, and a woman got out. Konno Hideko was driving to Namie – day trips are allowed, but overnight stays banned – to clean her parents’ former house and tidy an ancestral grave before relatives visited during an upcoming religious holiday. “My parents are dead now, but I still clean their house,” she said. “There are mice inside and wild boar have been in. We won’t ever return to live there. But we might build a new house there one day.”

Further along, Baba stopped the car and walked up a path swathed in vegetation. “This is my house,” he said suddenly, pointing to a barely visible building. It was shuttered. But I noticed laundry still hanging to dry in an upstairs window. On a tour of the grounds, Baba showed me his plum trees. “The fruit is too dangerous to eat now, and we can’t drink the water from the well, either.” We found a shed where he and his schoolteacher wife once kept cattle, and a former hay shed where he stored old election banners.

I checked my meter. It read 26 millisieverts per year in the hay shed, but shot up to an alarming 80 in undergrowth outside. That was four times the safe level for habitation. No wonder Baba had no plans to return. “I am just the son of a farmer. I wonder who has a right to destroy our home and my livelihood,” he mused bitterly. “Please tell the world: No Nukes.”

At his local post office, an official monitor by the road measured 56 millisieverts. Mine agreed, but when we pointed it close to a sprig of moss pushing through the tarmac, it went off the scale. “They measured 500 millisieverts here last week,” Baba said. “Moss accumulates radioactivity.”

As we drove on, the roadside was now marked every few kilometers by massive pyramids of black plastic bags, containing radioactive soil that had been stripped from roadside edges, paddy fields, and house gardens as part of government efforts to decontaminate the land. An estimated 3 million bags, all neatly tagged, now await final disposal at facilities planned along the coast. But the task of transporting the soil is so huge that the authorities are building a new road so trucks can bypass the scenic mountain villages along Highway 114.

Through a checkpoint we came at last to Namie town. Just before my visit, major media such as The Guardian and CNN had published images of the town by a photographer who claimed to have gained secret, unauthorized entry to the “ghost town.” He posed in his images wearing a gas mask to show how dangerous it was.

My visit to the town had required a request in advance, via Baba, but no subterfuge. And I found Namie a surprisingly busy “ghost town.” Nobody is yet allowed to live there. But some 4,000 people work there every day, repairing the railway line and roads, building new houses, and knocking down quake-damaged shops, preparing for the planned return of its citizens in April 2017.

There was plenty of earthquake damage, and vegetation pushed through cracks in the roads and the pavement in the front yards. Black bags were everywhere. But the traffic lights functioned, and drivers obeyed them; there was a 7-Eleven and the vending machines had Coke in them. Nobody wore protective clothing or masks. My biggest safety concern was not radiation, but the news, conveyed over the town’s public address system on the afternoon I was there, that a bear had been spotted in the suburbs.

Despite its proximity to the power plant, average radiation levels in the town were down to around 2 millisieverts per year in Namie – lower, in fact, than I recorded in Fukushima City, which was never evacuated.

“I have no idea how many people will come back,” said Baba. “They have a lot of misgivings because of the radioactive contamination. And I think their fears are totally justified. It is totally unthinkable for me to return to my old place, so I cannot encourage them to return to theirs.” He quoted a survey of the town’s 21,000 former residents showing that only 18 percent wanted to come back. That sounded similar to nearby Naraha town, where only a fifth returned after the all-clear was given last year.

People especially feared for their children. The biggest concern was reports of an epidemic of thyroid cancer among children exposed to radioactive iodine in the days after the accident. An ultrasound screening program had found an apparent 30-fold increase in cysts, nodules, and some cancers in children’s thyroid glands. It had made headline news.

But at the Fukushima Medical University, doctors and medical researchers insisted that radiation doses were far too low to pose a serious cancer risk, not least because contaminated foodstuffs that could have harbored the iodine were rapidly withdrawn from sale. Ken Nollet, an American who is director of radiation health at the university, insists that the apparent epidemic was evidence only of better searching for disease. He told me a Korean screening study using the same techniques on a non-exposed population found similar rates to those in Fukushima’s contaminated zone.

Thanks to the rapid, if chaotic, evacuation of the area after the power plant began its meltdown, and the controls of foodstuffs, doctors say they believe there are unlikely to be many, if any, deaths among the public from radiation from the Fukushima accident. “A few members of the public got a CT scan’s worth of radiation; almost nobody received more than the dose from a barium meal,” said Nollet.

But there have been deaths nonetheless. Some 60 old people died as a direct result of the evacuation, including several who died of hunger after being left behind, said a doctor at Soma hospital, Sae Ochi. And depression remains widespread among evacuees, she says. There have been around 85 suicides linked to its after-effects. “It’s post-traumatic stress,” said Masaharu Maeda at Fukushima Medical University. “People with very negative views about the risks of radiation are more likely to be depressed. It’s a vicious circle.”

Some doctors told me that while the initial evacuation was necessary, the failure to plan a swift return as radiation levels fell had been disastrous. Apart from a few high-dose areas in the mountains, the psychological risks of staying away exceed the radiological risks of coming back. But the confusion has contributed to a serious loss of trust among the public for medical, as well as nuclear, authorities. “When we try to explain the situation,” says Nollet, “we are seen as complicit in nuclear power.”

It seems increasingly unlikely that the majority of families will return to the abandoned towns as the official all-clear is given. As we drove back from Namie, I dropped in on a group of old women living in an evacuation camp outside Kawamata. One told me they wanted to return to their old homes, but that “most young people simply won’t go back. They fear for their children, but also they have moved on in their lives, with new jobs and their children in new schools.”

And maybe that is not a bad thing. At a kindergarten in Soma City, just outside the exclusion zone, teachers told me that, away from the fear of radiation, there was a baby boom going on there. The crop of new students this year was the largest since the accident. ”

by Fred Pearce

source

960 Bq/kg of Cs-134/137 detected from wild boar in Fukushima — Fukushima Diary

” According to MHLW (Ministry of Health, Labour and Welfare), 960 Bq/Kg of Cesium-134/137 was measured from the meat of wild boar in Fukushima.

The sampling date was 6/11/2016. This reading is over 9 times much as food safety limit.

Cs-134 density was 154 Bq/Kg to prove it is contaminated from Fukushima accident.

From this report MHLW released on 7/19/2016, significant density of Cs-134/137 was detected from all of 33 wild boar samples and it exceeded the food safety limit (100 Bq/Kg) in 2/3 samples.

MHLW reports none of these wild boar meat was distributed for sale. ”

by Iori Mochizuki

source with French translation

 

Greenpeace reports jump in radioactive contamination in Fukushima waterways — The Japan Times

” Greenpeace Japan on Thursday said it has discovered radioactive contamination in Fukushima’s riverbanks, estuaries and coastal waters at a scale hundreds of times higher than pre-2011 levels.

One sample of sediment taken along the Niida River, less than 30 km northwest of the crippled Fukushima No. 1 power plant, revealed the presence of cesium-134 and cesium-137 at levels of 29,800 becquerels per kilogram.

That was just one of 19 samples of dried sediment and soil the environmental activist group took and analyzed from the banks of the Abukuma, Niida, and Ota rivers. The samples were collected by Greenpeace in February and March.

All of the samples but one exhibited more than 1,000 Bq/kg of radioactive material. The lowest level, 309 Bq/kg, was logged at a spot along the Abukuma River.

Cesium-134 has a half-life of about two years, but cesium-137 has a half-life of 30 years and is considered particularly hazardous. The standard limits set for radioactive cesium in Japan are 100 Bq/kg for general foods and 10 Bq/kg for drinking water.

“The radiological impacts of the Fukushima nuclear disaster on the marine environment, with consequences for both human and nonhuman health, are not only the first years. They are both ongoing and future threats, principally the continued releases from the Fukushima No. 1 plant itself and translocation of land-based contamination throughout Fukushima Prefecture, including upland forests, rivers, lakes and coastal estuaries,” the report said.

Greenpeace Japan also published the results of tests on dried marine sediment samples collected at 25 points off the Fukushima coastal area, including three river estuaries, during this same period, at depths of between 7.4 and 30.6 meters. The results showed that the highest level of cesium was 144 Bq/kg taken from a sample collected off the coast from the Fukushima power plant, while the lowest total cesium figure was 6.5 Bq/kg off Nakanosaku, well to the south of the plant.

In addition to Fukushima, Greenpeace Japan took dried sediment samples from Lake Biwa at three locations near the shore. The results showed cesium levels to be between 7.1 Bq/kg and 13 Bq/kg at two locations, and negligible at the other two.

The safety of Lake Biwa, which provides drinking water for about 14 million people in the Kansai region, has become a major bone of contention between Kansai Electric Power Co., which wants to restart reactors in neighboring Fukui Prefecture, and residents in and around Lake Biwa who are fighting to keep them shut down. ”

by Eric Johnston

source

Scientists find new kind of Fukushima fallout — Forbes

” Some of the radioactive material that escaped the Fukushima Daiichi nuclear reactor in 2011 took a form no one was looking for, scientists have discovered. Now they have to figure out what it means for Japan and for future disasters.

Radioactive cesium—specifically, cesium-137—is one of the waste products of nuclear power. It’s also one of the most dangerous substances in a nuclear disaster like Chernobyl or Fukushima.

One reason why is that the type of radiation it emits is particularly damaging to our bodies. Another is that cesium-137 dissolves in water. That means it can spread quickly through the environment and get into the plants, animal and water we consume.

Until now, scientists and disaster experts thought cesium-137 fallout from the Fukushima reactor meltdown was in this soluble form. That guided their cleanup efforts, like removing and washing topsoil, and helped them map where radiation might spread.

It turns out that wasn’t entirely true. Satoshi Utsunomiya, a geochemist at Kyushu University in Japan, announced over the weekend that he had found cesium-137 in a new form: trapped inside tiny glass particles that spewed from the damaged reactors. These particles are not water soluble, meaning we know very little about how they behave in the environment—or in our bodies. He found the particles in air filters placed around Tokyo at the time of the disaster.

According to Utsunomiya, high temperatures inside the malfunctioning reactors at the Fukushima plant melted and broke down the concrete and metal in the buildings. Silica, zinc, iron, oxygen and cesium-137 fused into millimeter-wide glass microparticles, each about the size of a pin’s head. Lifted into the atmosphere by the fires raging at the plant, they then blew about 240 kilometers southwest to Tokyo.

“As much as 89% of all of the cesium [in Tokyo] was in fact in these particles. It’s profound,” says Daniel Kaplan, a geochemist at Savannah River National Laboratory in South Carolina. He attended Utsunomiya’s lecture describing the findings at the ongoing Goldschmidt Conference in Yokohama, Japan.

Kaplan says similar particles were observed near the Chernobyl reactors after the explosion there in 1986. But they were only seen within about 30 kilometers; beyond that, cesium-137 was only observed in rain.

Japanese researchers had previously found smaller versions of these cesium-containing glassy particles in Tsukuba, about 170 km from Fukushima, although apparently not at such high concentrations. One earlier paper also suggested that cesium-137 might work its way out of the particles over time.

The discovery could change how we model fallout from nuclear disasters. Kaplan explains that it might add a new variable to the models we use to predict where radioactive particles will go and how long they’ll stay there. It might also change how we treat cesium-137 during cleanup and monitoring.

It is probably still too early to say what this means for people living in Tokyo or elsewhere in Japan. Kaplan thinks the amount of radiation they received probably hasn’t changed. Whether they got it from water-soluble cesium-137 or from these particles, the radiation dose was the same—and for Tokyo residents, that number was within the margin of safe exposure.

The bad thing about water-soluble cesium-137 is that it can easily get into our bodies from soil by way of plants and animals. This new discovery alleviates that concern. But it opens up a new possibility we know little about.

“If the particles are in the air—because that’s how they get to Tokyo—then when you are aspirating this air you should find them in some ways on your lungs,” says Bernd Grambow, who studies nuclear waste chemistry as head of the SUBATECH laboratory in France.

Water-soluble cesium-137 that makes it into our lungs passes into the bloodstream and is peed out within a few weeks. But Grambow says we really don’t know what happens to insoluble cesium-137-containing particles if they get in our lungs. Some of them are likely coughed out or removed by our lungs’ other normal processes. As for the rest, Grambow says we don’t know how long they might remain.

He cautions that any internal radiation from particles containing cesium-137 would be much less than the doses people got from external radiation, which would come from cesium-137 and other radioactive elements in the soil or the environment around them. “We don’t know very much, and my point is only that they should be studied,” Grambow says.

Utsunomiya’s next step is finding out how much of the cesium-137 that ended up in soils in Tokyo and elsewhere was in these glass particles. That way, researchers will be able to better understand how cesium made its way out of the reactor and into the environment. “
by Sam Lemonick

Most radioactive caesium fallout on Tokyo from Fukushima accident was concentrated in glass microparticles — EurekAlert!; Simply Info

” New research shows that most of the radioactive fallout which landed on downtown Tokyo a few days after the Fukushima accident was concentrated and deposited in non-soluble glass microparticles, as a type of ‘glassy soot’. This meant that most of the radioactive material was not dissolved in rain and running water, and probably stayed in the environment until removed by direct washing or physical removal. The particles also concentrated the radioactive caesium (Cs), meaning that in some cases dose effects of the fallout are still unclear. These results are announced at the Goldschmidt geochemistry conference in Yokohama, Japan.

The flooding of the Fukushima Daiichi Nuclear Power Plant (FDNPP) after the disastrous earthquake on March 11 2011 caused the release of significant amounts of radioactive material, including caesium (Cs) isotopes 134Cs (half-life, 2 years) and 137Cs (half-life, 30 years).

Japanese geochemists, headed by Dr Satoshi Utsunomiya (Kyushu University, Japan), analysed samples collected from within an area up to 230 km from the FDNPP. As caesium is water-soluble, it had been anticipated that most of the radioactive fallout would have been flushed from the environment by rainwater. However, analysis with state-of-the-art electron microscopy in conjunction with autoradiography techniques showed that most of the radioactive caesium in fact fell to the ground enclosed in glassy microparticles, formed at the time of the reactor meltdown.

The analysis shows that these particles mainly consist of Fe-Zn-oxides nanoparticles, which, along with the caesium were embedded in Si oxide glass that formed during the molten core-concrete interaction inside the primary containment vessel in the Fukushima reactor units 1 and/or 3. Because of the high Cs content in the microparticles, the radioactivity per unit mass was as high as ~4.4×1011 Bq/g, which is between 107 and 108 times higher than the background Cs radioactivity per unit mass of the typical soils in Fukushima.

Closer microparticle structural and geochemical analysis also revealed what happened during the accident at FDNPP. Radioactive Cs was released and formed airborne Cs nanoparticles. Nuclear fuel, at temperatures of above 2200 K (about as hot as a blowtorch), melted the reactor pressure vessel resulting in failure of the vessel. The airborne Cs nanoparticles were condensed along with the Fe-Zn nanoparticles and the gas from the molten concrete, to form the SiO2 glass nanoparticles, which were then dispersed.

Analysis from several air filters collected in Tokyo on 15 March 2011 showed that 89% of the total radioactivity was present as a result of these caesium-rich microparticles, rather than the soluble Cs, as had originally been supposed.

According to Dr Satoshi Utsunomiya;

“This work changes some of our assumptions about the Fukushima fallout. It looks like the clean-up procedure, which consisted of washing and removal of top soils, was the correct thing to do. However, the concentration of radioactive caesium in microparticles means that, at an extremely localized and focused level, the radioactive fallout may have been more (or less) concentrated than anticipated. This may mean that our ideas of the health implications should be modified”.

Commenting, Prof. Bernd Grambow, Director of SUBATECH laboratory, Nantes, France and leader of the research group on interfacial reaction field chemistry of the ASRC/JAEA, Tokai, Japan, said:

“The leading edge observations by nano-science facilities presented here are extremely important. They may change our understanding of the mechanism of long range atmospheric mass transfer of radioactive caesium from the reactor accident at Fukushima to Tokyo, but they may also change the way we assess inhalation doses from the caesium microparticles inhaled by humans. Indeed, biological half- lives of insoluble caesium particles might be much larger than that of soluble caesium”. ”

Goldschmidt Geochemistry Conference

source

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Read a similar article by SimplyInfo that sheds more light on the radioactive fallout from Fukushima Daiichi.