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Hotspots in East Tokyo’s Mizumoto Park

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November 12, 2019
The soil of 12 out of 29 spots in Mizumoto Park (Katsushika-ward, Tokyo city) recorded more than 8000 Bq/kg of radioactive cesium. The highest measurement was over 42,000 Bq/kg.
水元公園かわせみの里残土 地図 Sample115
Here is another measurement data of the highest spot in the Park, which was recorded by a local volunteer in March 2019.

November 19, 2019 Posted by | fukushima 2019 | , , | Leave a comment

Tokyo’s Fukushima cesium-enriched microparticle (CsMP) update

CsMP-01-2.jpgSecondary electron images from Utsunomiya et al. 2019, of CsMPs discovered in atmospheric particles trapped on a Tokyo air filter from March 15, 2011, with major constituent elements displayed. 

 

August 17th, 2019

An interesting paper  was recently published by a team headed by Dr. Satoshi Utsunomiya of Kyushu University on the subject of Fukushima-derived cesium-enriched microparticles (CsMPs). As many readers will know, several researchers have located and analyzed these microparticles, in which the cesium is often bonded within glass-like silicates and therefore generally significantly less soluble than other Cs chemical species in water, though technically not actually “insoluble.” After an accident like Fukushima, it is much more common to find cesium in water-soluble compounds like cesium hydroxide (CsOH), and predictions about how quickly the cesium will be dispersed through the environment, in soil, in watersheds, taken up by plants and animals, etc, are based primarily on this assumption. The discovery of sparingly-soluble Fukushima-derived cesium microparticles, first documented by Adachi et al in 2013, and since then confirmed by many others, has raised a number of questions. How abundant are they? Does their presence increase health risk to humans? How much do they reveal about the process of the accident itself? From the standpoint of researchers the microparticles are very intriguing.

Utsunomiya et al.’s paper is titled “Caesium fallout in Tokyo on 15th March, 2011 is dominated by highly radioactive, caesium-rich microparticles,” and as noted in a recent Scientific American article, it was originally accepted for publication in 2017 by Scientific Reports journal. Weeks before publication, however, Tokyo Metropolitan Industrial Technology Research Institute (TIRI), operated by the Tokyo Metropolitan Government, raised objections with Scientific Reports. However no questions about the quality of the science or the validity of the paper’s findings appear to have been brought forward. This in itself was highly irregular. Two years elapsed without resolution, and in March of this year Scientific Reports took the highly unusual step of withdrawing its offer to publish the paper, despite the lack of confirmed evidence that would warrant it. Utsunomiya and several co-authors decided that the best course of action was to place the study in the public domain by publishing it via arXiv, a highly respected pre-print website. The paper is now open and free to download

This study makes a valuable contribution to the body of scientific literature regarding the consequences of the Fukushima disaster in general and CsMPs in particular. I think it was a mistake for Scientific Reports not to publish it two years ago, especially considering the rapid pace of research into these particles and the tremendous interest in them. To summarize the findings briefly, the researchers analyzed air filter samples from March 15, 2011, in Setagaya, Tokyo, when the radioactive plume from Fukushima caused a noticeable peak in airborne radioactivity in the city. The researchers used radiographic imaging (placing the filters on a photographic plate) to identify any highly radioactive spots. Using these images as a guide they were able to isolate seven CsMPs, which they subjected to atomic-scale analysis using high-resolution electron microscopy (HRTEM) to identify their nano-scale structure and chemical composition. Based on these detailed measurements and quantitative analysis, the researchers concluded that 80-89% of the total cesium fallout in Tokyo that day was in the form of highly radioactive microparticles. The second half of the paper is devoted to estimates of how long such particles might be retained in the human lungs if inhaled, based on previous studies that reported the effects of inhalation of non-radioactive atmospheric particles, and some possible physical consequences. The paper is valuable for the quantitative analysis of the Tokyo particles alone, since it is one of few studies that deal with the issue for Tokyo specifically. Research into possible health consequences of the particles, meanwhile, has gained momentum while the paper remained unpublished, using approaches such as stochastic biokinetics, and DNA damage studies.  In a recent paper, Utsunomiya and colleagues produced estimates of the rate of dissolution of the particles inside the human lung, in pure water, and in seawater. A working group at the Japan Health Physics Society has also devoted attention to the issue, noting the need for further study of the risk from intake of these particles, particularly to the lung.  Likewise, others have been studying the particles to learn about the accident progression and possible consequences for decommissioning.

Why did Tokyo Metropolitan Industrial Technology Research Institute object to the paper’s publication? When we first heard that publication of the paper was being held up by Tokyo Metropolitan Government, we thought politically-motivated suppression was a likely explanation. Since then the public has learned that the actual complaint given to Scientific Reports stems from a chain of custody issue of the original air filter samples. We don’t want to speculate further about Tokyo’s motivation, because we have seen no direct evidence yet of political suppression in this case. But based on past occurrences with other government institutions, we would find it plausible. We will let readers know if TIRI responds to our inquiries.

We spoke with Dr. Utsunomiya and co-author Dr. Rodney Ewing recently. I was aware of their co-authorship of several strong papers on CsMPs, including Utsunomiya’s plenary talk at the Goldschmidt Conference in Yokohama in 2016, which I attended. I asked how this new arXiv paper fits in with their other papers, and where they think this research is heading next:


Satoshi Utsunomiya:

Thank you for asking. The Tokyo paper was actually our first paper regarding CsMPs. As I mentioned, the paper was accepted two years ago. There were no previous papers of ours on CsMPs that time. Currently we are working on several topics on CsMPs. I cannot reveal the content yet, as we are thinking about a press release for the next paper. But I think it is important to continue this kind of research, providing some insights for decommissioning at Fukushima Daiichi Nuclear Power Plant.

Azby Brown:

I didn’t realize that this was your first paper on the subject.  How does it relate to the one presented at the Goldschmidt Conference in Yokohama in 2016? “Cesium-Rich Micro-Particles Unveil the Explosive Events in the Fukushima Daiichi Nuclear Power Plant.” Didn’t that paper receive a prize?

SU:

My talk at Goldschmidt briefly covered the story described in the two papers that were accepted for publication at the same time. One was published in Scientific Reports. The other one was not published. There was no prize. It was a plenary talk.

AB:

I see. I recall that it received a lot of attention. Now it makes more sense to me.

Can you tell me a little bit about the specific characteristics and focus of your research, and how it differs from papers like Adachi 2013, Abe 2014, etc? Generally speaking, that is. I’d like to help people understand the different aspects of the field.

SU:

Adachi reported the discovery of CsMPs. Abe demonstrated X-ray absorption analysis on the CsMPs. We focused on the nanotexture inside CsMPs. We are particularly interested in the detailed evidence remaining within the microparticle, which can provide useful information on the development of the chemical reactions during the meltdowns, because it is still difficult to directly analyze the materials inside the reactors. We, for the first time, succeeded in performing isotopic analysis on individual CsMPs. More specifically, the occurrence of uranium can directly tell the story of how the fuel melted. Our research has two directions: one is to understand the environmental impact of CsMPs, and the other is to provide useful information on the debris properties to help decommissioning at FDNPP. We are also interested in the implications for health.

AB:

Can you tell me a little bit about your working relationship? Satoshi went to the US to work in your lab, right Rod? When was that, and what were you working on?

Rod Ewing:

Satoshi and I have known each other since 2000, when he joined my research group as a post-doctoral fellow at the University of Michigan. He was a member of the research group until 2007. We collaborated on a wide range of topics that had to do with radioactive materials, such as the transport of plutonium at the Mayak site in Russia to the identification of uranium phases within C60 cages, so called buckyballs, that were formed and released from coal power plants. Once Satoshi returned to Japan to take his position at Kyushu University, we continued to collaborate, particularly on topics related to Fukushima Daiichi.

AB:

How did you both get interested in CsMPs?

RE:

Once discovered, CsMPs were clearly of high interest. They had not been noted in earlier reactor accidents. Satoshi is a master with the transmission electron microscope – exactly the tool/technique needed to study these particles.

AB:

For people who aren’t familiar with what’s involved in a research experiment like yours, can you describe the overall process? What were the technical challenges?

RE:

I would just emphasize that it is very difficult to find and characterize these particles. Considering the full literature and efforts by others as well as our team – the results are impressive. It is rare to have both the TEM characterization and the isotopic data.

SU:

As Rod mentioned, it is difficult to obtain both TEM and isotopic data from a few micron-sized spots. The isolation of CsMPs from soils is a time consuming process. But to date, many scientists have found and isolated CsMPs. The important thing is what information we can obtain from the analysis of CsMPs. We have been taking various approaches to elucidate the properties, environmental impact, and the role in releasing fissile actinides to the environment.    


As described above, many papers examining various aspects of Fukushima-derived cesium microparticles have been published since they were first identified in 2013. Even so, important aspects remain only partially documented and understood to date. Below is a partial list of relevant publications.

Papers mentioned in this article:

Caesium fallout in Tokyo on 15th March, 2011 is dominated by highly radioactive, caesium-rich microparticles

Utsunomiya, et al., 2019

https://arxiv.org/abs/1906.00212

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Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident

Adachi et al., 2013

http://www.nature.com/articles/srep02554

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Detection of Uranium and Chemical State Analysis of Individual Radioactive Microparticles Emitted from the Fukushima Nuclear Accident Using Multiple Synchrotron Radiation X-ray Analyses

Abe et al., 2014

http://pubs.acs.org/doi/abs/10.1021/ac501998d

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Dissolution of radioactive, cesium-rich microparticles released from the Fukushima Daiichi Nuclear Power Plant in simulated lung fluid, pure-water, and seawater

Suetake et al., 2019

https://doi.org/10.1016/j.chemosphere.2019.05.248

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Development of a stochastic biokinetic method and its application to internal dose estimation for insoluble cesium-bearing particles

Manabe & Matsumoto, 2019

https://doi.org/10.1080/00223131.2018.1523756

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DNA damage induction during localized chronic exposure to an insoluble radioactive microparticle

Matsuya et al., 2019

https://doi.org/10.1038/s41598-019-46874-6

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Provenance of uranium particulate contained within Fukushima Daiichi Nuclear Power Plant Unit 1 ejecta material

Martin et al., 2019

https://www.nature.com/articles/s41467-019-10937-z

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Internal doses from radionuclides and their health effects following the Fukushima accident

Ishikawa et al., 2018

https://iopscience.iop.org/article/10.1088/1361-6498/aadb4c

 



Related papers (by year of publication):

Characteristics Of Spherical Cs-Bearing Particles Collected During The Early Stage Of FDNPP Accident

Igarashi et al., 2014

http://www-pub.iaea.org/iaeameetings/cn224p/Session3/Igarashi.pdf

—————————————————————

Radioactive Cs in the severely contaminated soils near the Fukushima Daiichi nuclear power plant

Kaneko et al., 2015

https://www.frontiersin.org/articles/10.3389/fenrg.2015.00037

—————————————————————

First successful isolation of radioactive particles from soil near the Fukushima Daiichi Nuclear Power Plant

Satou et al., 2016

http://www.sciencedirect.com/science/article/pii/S2213305416300340

—————————————————————

Internal structure of cesium-bearing radioactive microparticles released from Fukushima nuclear power plant

Yamaguchi et al., 2016

http://www.nature.com/articles/srep20548

—————————————————————

Three-Year Retention Of Radioactive Caesium In The Body Of Tepco Workers Involved In The Fukushima Daiichi Nuclear Power Station Accident

Nakano et al., 2016

http://rpd.oxfordjournals.org/content/early/2016/03/14/rpd.ncw036

—————————————————————

Monte Carlo Evaluation of Internal Dose and Distribution Imaging Due to Insoluble Radioactive Cs-Bearing Particles of Water Deposited Inside Lungs via Pulmonary Inhalation Using PHITS Code Combined with Voxel Phantom Data

Sakama, M. et al., 2016

http://scholar.google.com/scholar_lookup?&title=Radiological%20Issues%20for%20Fukushima%E2%80%99s%20Revitalized%20Future&pages=209-220&publication_year=2016&author=Sakama%2CMinoru&author=Takeda%2CShinsaku&author=Matsumoto%2CErika&author=Harukuni%2CTomoki&author=Ikushima%2CHitoshi&author=Satou%2CYukihiko&author=Sueki%2CKeisuke

—————————————————————

Radioactively-hot particles detected in dusts and soils from Northern Japan by combination of gamma spectrometry, autoradiography, and SEM/EDS analysis and implications in radiation risk assessment

Kaltofen & Gundersen, 2017

https://www.sciencedirect.com/science/article/pii/S0048969717317953?via%3Dihub

—————————————————————

Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant

Furuki et al., 2017

https://www.nature.com/articles/srep42731

—————————————————————

Isotopic signature and nano-texture of cesium-rich micro-particles: Release of uranium and fission products from the Fukushima Daiichi Nuclear Power Plant

Imoto et al., 2017

—————————————————————

Uranium dioxides and debris fragments released to the environment with cesium-rich microparticles from the Fukushima Daiichi Nuclear Power Plant

Ochiai et al., 2018

https://pubs.acs.org/doi/abs/10.1021/acs.est.7b06309

—————————————————————

Novel method of quantifying radioactive cesium-rich microparticles (CsMPs) in the environment from the Fukushima Daiichi nuclear power plant

Ikehara et al., 2018

https://pubs.acs.org/doi/full/10.1021/acs.est.7b06693

—————————————————————

Formation of radioactive cesium microparticles originating from the Fukushima Daiichi Nuclear Power Plant accident: characteristics and perspectives

Ohnuki, Satou, and Utsunomiya, 2019

https://www.tandfonline.com/doi/abs/10.1080/00223131.2019.1595767

https://blog.safecast.org/2019/08/fukushima-cesium-enriched-microparticle-csmp-update/

August 22, 2019 Posted by | fukushima 2019 | , , , , | Leave a comment

Citizens Group Leader in Kashiwa Radiation Hotspot Quits

Kashiwa city, in Chiba prefecture is located 31.3 km ( 19.45 miles ) northeast from Tokyo.

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August 16, 2019

The leader of a Citizens’ Group to Protect Children from Hotspot Radiation in Kashiwa city, Chiba, decided to suspend its activities.

Mrs. Yuki Ohsaku, representative of the group evacuated recently to Kyushu after her two children started nosebleeding and other core members also are considering moving out of Kashiwa city. 10 members have already relocated.

In May the Kashiwa mayor wrote in his blog that those worried about the effects of radiation have some kind of mental problems. Kashiwa city originally had no plan to conduct any survey after citizens reported high radiation levels. Mrs. Ohsaku’s group collected over 10,000 signatures and submitted the petition to the City Council with 100 members, and this made the Kashiwa city start measuring radiation levels in schools and do decontamination work.

However, the group’s activities and her relocation with two children to Kyushu caused lots of problems within her family. Her in-laws are not happy that she is disobeying the authorities and that her name gets published (since she is the group leader). Now the in-laws are demanding that she divorce her husband. She says that old and middle-aged people in general have absolute confidence in the printed media as their news source, and what’s not reported in the newspapers is not conceived as reality.

The mainstream media (including newspapers) has the least coverage on health effects of radiation and only report the government’s “adjusted” radiation levels. Yomiuri News even wrote in May that the information about hotspots in Chiba are based on false rumours and that they doesn’t exist. (Matsutaro Shoriki, ex-president of Yomiuri was a CIA agent and is called the father of nuclear power in Japan according to Wikipedia.) She says her in-laws believe in the Yomiuri report.

Only those collecting information from internet sources are aware of what is really going on regarding radiation issues in Japan. As a result, there the public have split opinions on this subject.

Mrs. Ohsaku says the conflict of opinions on radiation issues has been harder to deal with than the radiation itself. Many people around her chose not to think about it and neighbors don’t want her to make it a big issue. Some members of her group are tired of being ridiculed as “freaks”. Her group wants decontamination but others in the hotspot thinks it’s waste of money. They say “Let’s not worry about it. Think of people in Fukushima. They live in an even worse environment than us.”

https://blog.safecast.org/2011/08/citizens-group-leader/

August 22, 2019 Posted by | fukushima 2019 | , , , , , , | Leave a comment

‘Shocked’ Fukushima evacuees say Tepco ruling fails to fairly compensate them for suffering

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Rice planting for commercial sales begins at a paddy in Iitate in May 2017, for the first time since the disaster at the Fukushima No. 1 nuclear power plant in 2011.
March 27, 2019
A Tokyo court on Wednesday ordered the operator of the crippled Fukushima nuclear plant to pay a total of ¥21.34 million in damages to a group of evacuees from the March 2011 nuclear disaster.
But the ruling by the Tokyo District Court, which was the 11th such decision against Tokyo Electric Power Company Holdings Inc., came as a shock to the evacuees, who claim the court has neglected their suffering.
The lawsuit was filed in March 2012 by 42 former residents of Iitate, a village in Fukushima Prefecture, who claim their lives were affected by the Fukushima No.1 nuclear plant disaster in 2011. They were forced to evacuate from the prefecture due to evacuation orders that were only lifted later, in March 2017. They had sought a combined ¥1.68 billion from the utility for their psychological suffering.
Presiding Judge Tetsuro Nakayoshi awarded compensation to 13 of the 42 plaintiffs whose damages were deemed more severe. The plaintiffs in general have been already compensated by the nuclear plant operator and had already found new homes, the court concluded. Only one pair was awarded the highest amount, of more than ¥3 million in damages, due to illness and required nursing care.
Read more:

March 31, 2019 Posted by | fukushima 2019 | , , | Leave a comment

Tokyo Not Fit For Human Habitation

giujk.jpg
This mother followed a doctor’s advice to evacuate from Tokyo due to the ill health of her daughter following the Fukushima Daiichi nuclear disaster. The doctor told her that 9 out of ten of his child patients in metropolitan Tokyo had reduced white blood cell counts due to exposure to radioactivity and that if they moved away some of them might recover. Many other families have evacuated from Tokyo but this has not been covered by the press. She speaks in English with an English transcription below the Japanese transcription.
“I am standing here to tell you that the Fukushima nuclear catastrophe is not over. I evacuated to Kansai three years after the Fukushima nuclear power plant accident. Where do you think I evacuated from? I evacuated from Tokyo. Do you know that Tokyo has serious radioactive contamination? Tens of millions of people in East Japan live with radioactive contamination now.
My daughter was 5 years old at the time of the accident She was a cheerful and active girl. But after one year since the accident, her health conditions became bad and she was troubled by strange symptoms.
She told me, “Mommy, I feel so bad, I have no power, My hands hurt, my legs hurt, my body hurts!” In fact, my daughter became so sick that she could not live a normal life at all.
At that time I met a doctor who was working with the issue of radiation exposure in the metropolitan area. He said, if sick children are moved to the west away from contaminated eastern Japan, some of them might recover health.
According to his examinations after the accident, the number of white blood cells of children living in the metropolitan area was decreasing. And he added that neutrophils among white blood cells were particularly badly decreasing. And as we found out later, our two children also had the same condition. Today, the doctor is saying that for every ten children in Tokyo, nine of them have below standard numbers of neutrophils.
When I consulted the doctor about my daughter, he clearly stated that she was affected by the radiation exposure.
And he gave me advice to move my daughter
In any case, I tried to move my sick daughter out of Tokyo. Whenever we stayed in a place where there was no radioactive contamination, she became very well. But when we returned to Tokyo, she became sick again. We did not have the option to stay in Tokyo, we just fled from Tokyo and came here.
Living in East Japan means living with many radioactive materials, and it is not a place where people can live in good health.
So, as evacuees from eastern Japan, we are calling for evacuation to West Japan. Our existence here is not broadcasted on the radio nor published in newspapers. So, I am telling you about it now.
After the accident, we were told that radiation was not a problem and health damages would not occur. But it was not true. Many of us have evacuated from East to West due to various health problems. Many people are getting sick today in East Japan. People are dying without noticing that it is due to radiation. Many Japanese can not face this nuclear catastrophe.
Now my daughter is 12 years old. She’s healthy and enjoys everyday life. She has good friends and says she wants to continue living here forever.
My daughter wrote this , It says she wants to stay here with her friends forever.
She is very afraid that nuclear power plants now get restarted and may have another accident. If that happens, she will have to move away from here again. If another nuclear accident happens, she knows that she can not live in this country anymore.
And accidents are not the only ones that threaten her. This is a basic issue but after the accident, our government has not confined radioactive materials to one place.
On the contrary, our government has a policy of diluting toxic radioactive waste by mixing it with water, cement or other materials, and making it look harmless.
And the Japanese government now allows incineration of highly contaminated nuclear waste of up to 8000 Bq/kg, 80 times as high as before the Fukushima accident. It’s all to reduce the enormous amount of nuclear waste. But as conscientious scientists say, we should never burn radioactive materials. It should never have been allowed.
We don’t seem to be able to stop this crazy, irresponsible way of our government.
I hope that my daughter can live in her beloved country where she was born and raised. Please try to know what is going on in Japan now.
We are telling the world that the nuclear disaster is far from being over.”
In addition Dr Shigeru Mita closed his medical practice in Tokyo in 2014 and left the city, declaring it “not fit for human habitation” when he found that all his child patients of 10 years old and under had reduced neutrophils and other illnesses due to “chronic internal exposure to low dose ionising radiation”:

giujk.jpg

January 29, 2018 Posted by | Fukushima continuing | , | Leave a comment

Testimony of a mother who evacuated from Tokyo

Listen to her testimony (in English).
She evacuated from Tokyo to Kobe in west Japan to protect her daughter.
The contamination does not stop at the Fukushima department border. Tokyo is also contaminated.

 

 
Transcription (note 1):
I am standing here to tell you that the Fukushima nuclear catastrophe is not over.
I evacuated to Kansai (note2), three years after the Fukushima nuclear power plant accident.
Where do you think I evacuated from?
I evacuated from Tokyo!
Do you know that Tokyo has serious radioactive contamination?
Tens of millions of people in east Japan live with radioactive contamination now.
I have a daughter who was 5 years old at the time of the accident.
She became very sick one year after the accident.
In fact, my daughter became so sick that she could not live a normal life at all.
However, when she stayed in a place where there was no radioactive contamination, my daughter became so well. But when we returned to Tokyo, my daughter became sick again.
We did not have the option to stay in Tokyo, we just fled from Tokyo and came here.
Living in east Japan means living with many radioactive materials, and it is not a place where people can live healthily.
We are calling for evacuation to west Japan.
We are evacuees from eastern Japan.
Our existence will not be broadcasted on radio waves or published in newspapers. So, I am telling you about it now.
After the accident, we were told that radiation was not a problem, health damages would not occur.
But it was not true.
Many of us have evacuated from east to west due to various health problems.
Many people are getting sick today in east Japan.
People are dying without noticing that it is due to radiation.
Many Japanese can not face this nuclear catastrophe.
Please try to know what is going on in Japan now.
We are telling the world that the nuclear disaster is far from being over.
 
 
Note 1: We thank Ms Yoko Chase for her proofreading of the text prepared by Ms Yoko Shimozawa.
Note 2: The region in west Japan, including large cities such as Osaka, Kyoto and Kobe.

November 28, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Radioactive contamination in the Tokyo metropolitan area in the early stage of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident and its fluctuation over five years

journal.pone.0187687.g001.PNG
Fig 1. Sampling sites of soil samples.

Geographical distribution of the 134+137Cs precipitation referred to the aircraft monitoring results by the MEXT of Japan on December 16, 2011 [30]. Adapted from ‘Extension Site of Distribution Map of Radiation Dose, etc.’ (http://ramap.jmc.or.jp/map/).

 

The activity and inventory of radioactive material in the eastern part of Tokyo tended to be high… The radioactive plume with high 131I activity spread into the Tokyo metropolitan area…
Almost no public information about the radioactive contamination in the Tokyo metropolitan area and Kanto district had been shared…
The plume containing a large amount of radioactive material drifted into the Tokyo metropolitan area… where over 30 million residents live… [Publications] include almost no discussion of the fact that radioactive materials were carried into the Tokyo metropolitan area…
The contamination level was extremely high in a roadside ditch sludge in Kashiwa City…
The quantity of 134+137Cs deposited in the region studied was estimated… from values measured in the soil, it was estimated as 5.35 TBq…
High activities and inventories of the radionuclides were found in eastern Tokyo and northern Chiba… The contamination was even higher in the adjoining northern part of Chiba located east of Tokyo…
The results reveal that the Tokyo metropolitan area even now continues to be affected by radioactive contamination caused by the FDNPP accident…
Gordon Edwards, Ph.D, nuclear expert, 2017 (pdf): Intensive contamination extends over 200 km south – right down to the outskirts of Tokyo
IRSN, 2016 (pdf): Fukushima-Daiichi Accident: Main contamination events… Event of 14-16 March – This event is marked by turning winds and by a rainfall that generated significant contamination of the Japanese territory. On the evening of the 14th of March, a first radioactive plume was transported by winds towards the southwest… and reached the Tokyo area. At Tsukuba, 153 Bq/m3** were measured…
** 153 Bq/m3 = 153,000,000 uBq/m3 Cs-137 in Tsukuba after Fukushima vs. 1.2 uBq/m3 Cs-137 in Tsukuba before Fukushima (source) = 127,500,000 times higher Cs-137 after Fukushima

November 18, 2017 Posted by | Fukushima 2017 | , | Leave a comment

High Risk of Inhaling Cesium Contained in Shower Near Tokyo

Via Kurumi Sugita

Screenshot from 2017-09-07 22-23-47

 

The result of analysis of a cartridge filter of shower water using essentially zeolite. The user lives in Funabashi city in Chiba (near Tokyo).

The period of use is from Feb 2017 to August 2017.
The volume of water used is about 52500L.

Cesium fixed in cartridge is 1128.96 Bq/kg

While taking a shower, one is exposed to a high risk of inhaling cesium contained in the steam.

http://cdcreation.grupo.jp/blog/1887327

September 7, 2017 Posted by | Fukushima 2017 | , | 1 Comment

Radioactive Contamination from Fukushima Nuclear Disaster: Did You Know that Tokyo Metropolitan Area is Widely Contaminated Too?

We are “GO WEST & COME WEST!!! 3.11 Evacuees from Tokyo area”.

Etsuji Watanabe, one of the members of Association for Citizens and Scientists Concerned about Internal Radiation Exposures (ACSIR), estimates that each year at most 180,000 people may develop cancer and 90,000 will be killed by cancer or some other causes.

Radiation Levels in Tokyo Metropolitan Area (Year 2013~2015: µSv/hour)

Screenshot from 2017-09-07 23-25-23.png

Estimation of the risk for 10 million people in Tokyo Metropolitan area exposed by radiation (2.4mSv/year).

Data provided by Mr. Kirishima.

Screenshot from 2017-09-07 23-25-49.png

* Risk occurrence: 10,000 person-Sv

** According to a book ‘Chernobyl: Consequences of the Catastrophe for People and the Environment’ by Alexey V. Yablokov, ratio of death caused by cancer and not by cancer is 1 to 1.

Fukushima Radiation is Now Spreading to Tokyo and Eastern Japan

The child thyroid cancer which were commonly seen after Chernobyl accident is being found even around Tokyo area after several years from 3.11 Fukushima accident in 2011.

Severe illness such as various cancers, leukemia, and cardiac infarction are increasing too at alarming rate. For some people, immune system has also weakened due to radiation effects, and the conditions of their chronic disease or common cold are worsening.

Therefore some people from Tokyo have evacuated to safer places.

However Japanese government (and main media) continue to ignore the effects of Fukushima radiation even though the radiation level is still dangerously high. The government have recently lifted evacuation orders for the restricted residence areas and cut housing subsidies for evacuees, forcing them to believe it is safe to return.

Therefore some people think it is nonsense to evacuate from Tokyo area and believe the evacuees are over-reacting. Many of the evacuees are feeling very isolated and are living in poverty after moving to safer locations, forcing some to return to the contaminated area against their will.

About 45 million people still remain in contaminated metropolitan area in Tokyo. But many people are started feeling very ill one after another. In fact many of my friends living in Tokyo or Eastern Japan have collapsed from numerous illnesses over these years.

It has proven that an increase of serious illness was seen four-to-five years after 1986 Chernobyl meltdown and hundreds of thousands of people lost their lives.

Now we are facing the same situation in Tokyo and eastern Japan.

Fukushima radiation problem permits no delay. We need to encourage people in Tokyo and Eastern Japan to evacuate to safer places to protect their lives.

In order to fight against the inhumanity of the Japanese government toward lives of people and uncover the fact of radiation effect in Japan, it is urgently needed to spread the information like this to the public.

http://www.gowest-comewest.net/statement/20170825english.html

September 7, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Tokyo’s Tap Water Contaminated

Via Kaye Nagamine

A Japanese local magazine gives the list of prefectures where Cesium 134 and Cesium 137 have been detected in their tap water !

The left column gives the name of the prefecture. The central column gives the Cesium 134 detected and the right column the Cesium 137 : in white with three Chinese characters reads “not detected” while in black the white figures indicates the level of bq detected.

The third line from the bottom is Tokyo. Cesium 134 and Cesium 137 have both been detected in its tap water at high levels!

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Source: https://jisin.jp/serial/%E7%A4%BE%E4%BC%9A%E3%82%B9%E3%83%9D%E3%83%BC%E3%83%84/disaster/26165

September 2, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Delicious Fukushima Peaches at the “konbeni” Checkout

Via Bruce Brinkman on August 16, 2017
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Don’t forget to pick up some delicious Fukushima peaches at the *konbeni* checkout
 
Never mind the “harmful rumors”
(a.k.a. measurements of cesium 137, cesium 134, strontium 90, americium, plutonium, uranium, and a splattering of other radionuclides)
 
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and as the next days those peaches just aren’t moving: ¥50 off to help sales !

August 17, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Study: Radioactive Hot Particles Still Afloat Throughout Japan Six Year After Fukushima Meltdowns

Radioactive particles of uranium, thorium, radium, cesium, strontium, polonium, tellurium and americium are still afloat throughout Northern Japan more than six years after a tsunami slammed into the Fukushima Daiichi Power Plant causing three full-blown nuclear meltdowns. That was the conclusion reached by two of the world’s leading radiation experts after conducting an extensive five-year monitoring project.

Arnie Gundersen and Marco Kaltofen authored the peer reviewed study titled, Radioactively-hot particles detected in dusts and soils from Northern Japan by combination of gamma spectrometry, autoradiography, and SEM/EDS analysis and implications in radiation risk assessment, published July 27, 2017, in Science of the Total Environment (STOLEN).

Gundersen represents Fairewinds Associates and is a nuclear engineer, former power plant operator and industry executive, turned whistleblower, and was CNN’s play-by-play on-air expert during the 2011 meltdowns. Kaltofen, of the Worcester Polytechnic Institute (WPI), is a licensed civil engineer and is renowned as a leading experts on radioactive contamination in the environment.

415 samples of “dust and surface soil” were “analyzed sequentially by gamma spectrometry, autoradiography, and scanning electron microscopy with energy dispersive X-ray analysis” between 2011 and 2016. 180 of the samples came from Japan while another 235 were taken from the United States and Canada. The study further clarifies, “Of these 180 Japanese particulate matter samples, 57 were automobile or home air filters, 59 were surface dust samples, 29 were street dusts (accumulated surface soils and dusts) and 33 were vacuum cleaner bag or other dust samples.”

108 of the Japanese samples were taken in 2016, while the other 72 were gathered in 2011 after the meltdowns. Gundersen and Kaltofen tapped 15 volunteer scientists to help collect the dust and soil — mostly from Fukushima Prefecture and Minamisouma City. “A majority of these samples were collected from locations in decontaminated zones cleared for habitation by the National Government of Japan,” the study revealed. For the 108 samples taken in 2016, an “International Medcom Inspector Alert surface contamination monitor (radiation survey meter) was used to identify samples from within low lying areas and on contaminated outdoor surfaces.”

A Fairewinds Associates’ video from 2012 features Gundersen collecting five samples of surface soil from random places throughout Tokyo — places including a sidewalk crack, a rooftop garden, and a previously decontaminated children’s playground. The samples were bagged, declared through Customs, and brought back to the U.S. for testing. All five samples were so radioactive that according to Gundersen, they “qualified as radioactive waste here in the United States and would have to be sent to Texas to be disposed of.” Those five examples were not included as part of the recently released study, but Gundersen went back to Tokyo for samples in 2016. Those samples were included, and were radioactive, and according to Gundersen were “similar to what I found in Tokyo in [2012].”

 

Furthermore, 142 of the 180 samples (about 80 percent) contained cesium 134 and cesium 137. Cesium 134 and 137, two of the most widespread byproducts of the nuclear fission process from uranium-fueled reactors, are released in large quantities in nuclear accidents. Cesium emits intense beta radiation as it decays away to other isotopes, and is very dangerous if ingested or inhaled. On a mildly positive note, the study shows that only four of the 235 dust samples tested in the United States and Canada had detectable levels of cesium from Fukushima.

Cesium, due to its molecular structure, mimics potassium once inside the body, and is often transported to the heart where it can become lodged, thereafter mutating and burning heart tissue which can lead to cardiovascular disease. Other isotopes imitate nutritive substances once inside the body as well. Strontium 90 for example mimics calcium, and is absorbed by bones and teeth.

“Different parts of the human body (nerves, bones, stomach, lung) are impacted differently,” Kaltofen told EnviroNews in an email. “Different cells have radio-sensitivities that vary over many orders of magnitude. The body reacts differently to the same dose received over a short time or a long time; the same as acute or chronic doses in chemical toxicity.”

In contrast to external X-rays, gamma, beta or alpha rays, hot particles are small mobile pieces of radioactive elements that can be breathed in, drunk or eaten in food. The fragments can then become lodged in bodily tissue where they will emanate high-intensity ionizing radiation for months or years, damaging and twisting cells, potentially causing myriad diseases and cancer. The study points out, “Contaminated environmental dusts can accumulate in indoor spaces, potentially causing radiation exposures to humans via inhalation, dermal contact, and ingestion.”

The study also explains, “Given the wide variability in hot particle sizes, activities, and occurrence; some individuals may experience a hot particle dose that is higher or lower than the dose calculated by using averaged environmental data.” For example, a person living in a contaminated area might use a leaf blower or sweep a floor containing a hefty amount of hot particle-laden dust and receive a large does in a short time, whereas other people in the same area, exposed to the same background radiation and environmental averages, may not take as heavy a hit as the housekeeper that sweeps floors for a living. People exposed to more dust on the job, or who simply have bad luck and haphazardly breathe in hot radioactive dust, are at an increased risk for cancer and disease. High winds can also randomly pick up radioactive surface soil, rendering it airborne and endangering any unsuspecting subject unlucky enough to breath it in.

Hot particles, or “internal particle emitters” as they are sometimes called, also carry unique epidemiological risks as compared to a chest X-ray by contrast. The dangers from radiation are calculated by the dose a subject receives, but the manner in which that dose is received can also play a critical factor in the amount of damage to a person’s health.

“Comparing external radiation to hot particles inside the body is an inappropriate analogy,” Gundersen told EnviroNews in an email. “Hot particles deliver a lot of energy to a very localized group of cells that surround them and can therefore cause significant localized cell damage. External radiation is diffuse. For example, the weight from a stiletto high heal shoe is the same as the weight while wearing loafers, but the high heal is damaging because its force is localized.”

Kaltofen elaborated with an analogy of his own in a followup email with EnviroNews saying:

Dose is the amount of energy in joules absorbed by tissue. Imagine Fred with a one joule gamma dose to the whole body from living in a dentist’s office over a lifetime, versus Rhonda with exactly the same dose as alpha absorbed by the lung from a hot particle. Standard health physics theory says that Fred will almost certainly be fine, but Rhonda has about a 10 percent chance of dying from lung cancer — even though the doses are the same.

External radiation and internal hot particles both follow exactly the same health physics rules, even though they cause different kinds of biological damage. Our data simply shows that you can’t understand radiation risk without measuring both.

Some isotopes, like plutonium, only pose danger to an organism inside the body. As an alpha emitter, plutonium’s rays are blocked by the skin and not strong enough to penetrate deep into bodily tissue. However, when inhaled or ingested, plutonium’s ionizing alpha rays twist and shred cells, making it one of the most carcinogenic and mutagenic substances on the planet.

“Measuring radioactive dust exposures can be like sitting by a fireplace,” Dr. Kaltofen explained in a press release. “Near the fire you get a little warm, but once in a while the fire throws off a spark that can actually burn you.”

“We weren’t trying to see just somebody’s theoretical average result,” Kaltofen continued in the press release. “We looked at how people actually encounter radioactive dust in their real lives. [By] combining microanalytical methods with traditional health physics models… we found that some people were breathing or ingesting enough radioactive dust to have a real increase in their risk of suffering a future health problem. This was especially true of children and younger people, who inhale or ingest proportionately more dust than adults.”

“Individuals in the contaminated zone, and potentially well outside of the mapped contaminated zone, may receive a dose that is higher than the mean dose calculated from average environmental data, due to inhalation or ingestion of radioactively-hot dust and soil particles,” the study says in summation. “Accurate radiation risk assessments therefore require data for hot particle exposure as well as for exposure to more uniform environmental radioactivity levels.”

https://www.environews.tv/072917-study-plutonium-hot-particles-still-afloat-throughout-japan-six-year-fukushima-meltdowns/

July 31, 2017 Posted by | Fukushima 2017 | , , , , | Leave a comment

Bullying cases targeting young Fukushima evacuees spread to Tokyo

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Fresh cases of bullying targeting children who evacuated from Fukushima Prefecture following the 2011 nuclear disaster have emerged in Tokyo.

According to Tokyo Saigai Shien Netto (Tossnet), a group of lawyers supporting Fukushima evacuees, three schoolchildren who moved to Tokyo in the wake of the triple core meltdowns at the Fukushima No. 1 nuclear power plant were subjected to bullying at an elementary school in Chiyoda Ward between 2011 and 2015.

According to the group, one elementary school student and two others who are now in junior high school were called names repeatedly, with classmates shunning them by saying they could spread radiation. One of the children recalled being called kin (germ).

The group on Monday reported the incidents as cases of bullying to the board of education in Chiyoda Ward. The board said it had not been aware of the incidents and will look into the matter.

Chiyoda Ward is also investigating a separate case in which another student from Fukushima at a junior high school was allegedly forced to buy snacks for three other students.

The revelation comes in the wake of a bullying case in Yokohama, where a 13-year-old boy had been forced to pay ¥1.5 million to classmates at an elementary school he transferred to following the disaster.

After initially denying the claim, on Feb. 13 the Yokohama Board of Education acknowledged the payments made by the boy to classmates in the school were the result of bullying.

The boy entered the elementary school in Yokohama as a second-grader in August 2011, but after being called kin he began missing school in the third grade, according to a report released by the board.

The boy’s parents told the school in May 2014 that their son was a victim of bullying and told the police in July that he was involved in money trouble with his classmates.

http://www.japantimes.co.jp/news/2017/03/02/national/social-issues/bullying-cases-targeting-young-fukushima-evacuees-spread-tokyo/#.WLgoa3_ia-d

March 2, 2017 Posted by | Fukushima 2017 | , , | Leave a comment

Long-distance transport of radioactive plume by nocturnal local winds

Long-distance transport of radioactive plume by nocturnal local winds

Abstract

Radioactive plumes can spread far and wide depending on wind conditions. The plumes often frequently reached the Tokyo metropolitan area, which is approximately 200 km away from the Fukushima Daiichi nuclear power plant, under spatially heterogeneous wind fields in March 2011. To reduce exposure to radioactive plumes, the behaviour of the plumes must be known. However, the transport mechanism of radioactive plumes is not fully understood. Using a regional climate model, we show that multiple diurnal cycle processes play a key role in the frequent transport of radioactive plumes to the Tokyo metropolitan area. The observed data and hindcast results indicate that the radioactive plume moves along the local winds, which comprise the northeasterly local wind (NELW) associated with the meso-scale low-pressure system (meso-low) and the northerly sea wind (NSW) during the night. The long-term analysis and sensitivity simulations also show the nocturnal processes that the NELW caused by the meso-low and the NSW are formed east of the Tokyo metropolitan area and from Fukushima offshore east of the Tokyo metropolitan area, respectively, when neither winter monsoons nor extra-tropical cyclones are predominant. These findings indicate that the radioactive plumes could reach faraway places frequently via nocturnal local processes.

Introduction

Radioactive plumes can scatter widely under the strong influence of the weather1,2,3,4,5,6,7,8. After the accident at the Fukushima Daiichi nuclear power plant in March 2011, the Japanese government evacuated the area within a 20-km radius of the power plant and advised residents within a 20-km to 30-km radius of the power plant to stay inside their homes9. However, high air doses were observed in faraway places outside the 30-km radius (Fig. 1a,b). In such situations, exposure should be minimized because the released radioactive material (131I) is assumed to have the potential to cause thyroid cancer10. Therefore, when and where radioactive plumes will travel should be known in advance.

 

Figure 1: A common feature of the atmospheric fields when a high air dose was observed in the Tokyo metropolitan area.

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(a) The locations of Fukushima, Tokai-mura, and the Tokyo metropolitan area. (b) Time variations of the observed air doses at the observation sites in Tokai-mura. Cases 1, 2, 3, and 4 correspond to the spikes in the air dose. (c) The wind field and geo-potential height of MSM-GPV (975 hPa) at midnight before each of the four cases. Dark areas indicate low pressure. The maps were created by using GrADS 2.0.1 (http://cola.gmu.edu/grads/) (a,c) and Microsoft Excel for Mac 2011 (b).

 

The movement of a radioactive plume is not only influenced by large-scale events, such as monsoons and extra-tropical cyclones, but also by local-scale events4,5. For example, local-scale events, including land/sea breezes, are predominant under calm weather conditions11,12. A land/sea breeze can cause severe atmospheric pollution even in areas that are distant from the emission source13,14,15. A contamination could occur in a specific area because of the local circulation if large amounts of radioactive materials are emitted over a long period.

A large quantity of radioactive 131I, estimated to be between 1.8 × 1012 and 8.9 × 1015 Bq h−1, was released from the Fukushima Daiichi nuclear power plant by the end of March 201116,17,18. To represent the transport and deposition distribution of radioactive materials in Japan, several numerical simulations have been performed using the estimated emission data3,4,5,6,7,8,16,17,18. However, simulating the distributions is difficult because many uncertainties affect numerical simulations. One such uncertainty is the chaotic behaviour of the atmosphere19,20, which amplifies prediction errors resulting from imperfections in the model formulation or the sensitive dependence on the initial conditions. Indeed, if chaotic behaviour were predominant, the movement of the radioactive plume would be difficult to predict accurately.

In contrast, predicting the movement of a radioactive plume would be relatively simple if large-scale events, such as monsoons and extra-cyclones, were predominant because the wind field would be expected to be temporally constant and spatially homogeneous. However, radioactive plumes often reached the Tokyo metropolitan area, even under spatially heterogeneous wind fields5. The types of atmospheric events that might have affected the wind field and the mechanisms by which the radioactive plumes travelled over long distances remain poorly understood. The chaotic behaviour of the atmosphere might be associated with the movement of the radioactive plume. Here, we investigate the mechanism of radioactive plume transport from Fukushima to the Tokyo metropolitan area using a regional climate model.

Results

High air doses, indicated by the spike in Fig. 1b, were often observed at Tokai-mura in the eastern coastal region of the Tokyo metropolitan area in the morning. At approximately the same time, the NSW and the NELW commonly occurred near the coastal area of the northeastern region of the Tokyo metropolitan area at 975 hPa (see Supplementary Fig. S1), whereas these winds were not detected at 850 hPa (see Supplementary Fig. S2). Another common feature, the nocturnal meso-low, formed in the Tokyo metropolitan area before the high dose rates were observed east of the Tokyo metropolitan area in the morning (Fig. 1c). We conducted a hindcast (HC run) to confirm the relationship between the observed high air radiation doses and the radioactive plume simulated using a regional climate model21 (see Methods). The simulated radioactive plume occurred from Fukushima to the northeastern part of the Tokyo metropolitan area in all cases (see Supplementary Fig. S3).

We assumed that the NSW, NELW, and nocturnal meso-low strongly influenced the radioactive plume transport when neither winter monsoons nor extra-cyclones were predominant. Some diurnal cycle processes could have formed the NSW, NELW, and nocturnal meso-low if the diurnal variations of those atmospheric fields were confirmed in the long-term composite data during calm weather. To verify this hypothesis, we defined a typical day when diurnal wind was observed as a calm day using station data for the central part of the Tokyo metropolitan area. The four cases shown in Fig. 1 were included in the calm day. The diurnal variations were investigated by using the operational meteorological analysis dataset for March from 2008 to 2014 (see Supplementary Fig. S4 and Methods). Seven-year composite would be sufficient to detect the signal of diurnal cycle significantly.

The results demonstrated that the NSW, NELW, and meso-low were clearly evident in the composite of the calm day (Fig. 2b,c) at 975 hPa at night, whereas these atmospheric fields were unclear at 850 hPa (Fig. 2g–i). The meso-low could strongly influence the formation of the NELW. Additionally, the NSW and NELW could be formed as gravity currents induced by the meridional temperature gradient because no predominant forcing exists except for the temperature gradient at night under calm conditions. In contrast, the onshore wind, which is intensified by the heat-low at the mountains of central Japan14, is clearly evident in the daytime (Fig. 2a,d). Almost 30% of the days in March from 2008 to 2014 were calm days (see Supplementary Fig. S5). Thus, diurnal cycle processes are not rare events but are important contributors to the regional climate in March.

 

Figure 2: Diurnal variation of the wind fields under calm conditions.

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Diurnal variation of the composite data of wind fields, geo-potential height, and temperature at 975 hPa and 850 hPa on calm days from 2008 to 2014 according to the MSM-GPV data. The dark areas indicate areas of low geo-potential height (low pressure). The maps were created by using GrADS 2.0.1 (http://cola.gmu.edu/grads/).

 

The nocturnal meso-low forms in various areas worldwide22,23,24,25,26. The topographical heat-low in the daytime could be a trigger of the meso-low23. However, the nocturnal meso-low has been observed to persist until the morning (Fig. 2c). If the convergence caused by the NSW sustains the meso-low, the topographic effect and meridional temperature gradient could be important in the formation of the meso-low.

To elucidate the formation mechanisms of the NSW, NELW, and meso-low, we conducted simple sensitivity tests (see Methods). The effect of the meridional temperature gradient was investigated by adapting a monthly averaged global zonal mean field in March 2011 as the initial and boundary conditions (Ex. 1); the effect of geography, including the land/sea contrast, was investigated by adapting the area-averaged atmospheric field around east Japan (Ex. 2) (see Supplementary Fig. S6). The result shows that Ex. 1 simulates the NSW, NELW, and meso-low but Ex. 2 does not (Fig. 3). This finding indicates that the meridional temperature gradient is essential in the formation of the diurnal cycle of the atmospheric field.

 

Figure 3: Sensitivity test.

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The wind fields, geo-potential heights, and temperatures at 975 hPa in the morning (6 JST) of Ex. 1 and Ex. 2. The atmospheric fields of the global zonal mean and area-averaged values in March 2011 were applied as the lateral boundary conditions of Ex. 1 and Ex. 2, respectively. The maps were created by using GrADS 2.0.1 (http://cola.gmu.edu/grads/).

 

Discussion

A schematic of the transport of radioactive materials is presented in Fig. 4. The radioactive materials are transported to an area offshore of Fukushima by the land breeze, and then, the plume moves to the south via the NSW (Fig. 4a). In the morning, the radioactive plume flows into the Tokyo metropolitan area via the NELW, which is formed by the nocturnal meso-low (Fig. 4b). In the afternoon, the plume moves to the mountain area located to the northeast of the Tokyo metropolitan area because of the intensified sea breeze induced by the heat-low over the mountains in central Japan (Fig. 4c).

 

Figure 4: Long-distance transport of the radioactive plume via multiple diurnal processes.

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The 3D image of the mixing ratio of 131I in Case 1. The maps were created by using Volume Data Visualizer for Google Earth (VDVGE) 1.1.7 ESC JAMSTEC (https://www.jamstec.go.jp/esc/research/Perception/vdvge.ja.html) and Adobe Illustrator CS5

 

The northeasterly wind accompanied by rain is often observed around the Tokyo metropolitan area during winter mornings27,28,29. The developed nocturnal meso-low is responsible for this precipitation. Consequently, it was reassuring that no rainfall was detected on 15 March 2011, when the highest air doses were observed (case 1 in Fig. 1). If rainfall had occurred, the serious contamination would have also caused in the Tokyo metropolitan area.

In the seven-year simulation with the constant emission of radioactive materials (CE run), a high deposition of 131I was simulated from Fukushima to the Tokyo metropolitan area in the morning, with increased deposition occurring the mountains located east of the Tokyo metropolitan area in the evening (see Supplementary Fig. S7 and Methods). The diurnal variation of the deposition could be explained by the movement of the radioactive plume corresponding to the diurnal wind field shown in Fig. 4. Thus, diurnal processes strongly influence the deposition distribution.

The amounts of radioactive materials deposited, especially 137Cs, depend strongly on the precipitation30. Generally, precipitation is difficult to simulate using a numerical model quantitatively with high accuracy because of the non-linearity of the precipitation process. Therefore, accurately estimating the deposition at a specific point without observations would be difficult. Therefore, using only the simulated deposition (exposure by groundshine), determining whether immediate evacuation should be enforced is problematic. Our new findings will be useful for determining the time to take shelter to avoid exposure to the radioactive plume (by cloudshine and/or intake) when a large-scale event is not predominant. Additionally, by applying the transport mechanism clarified here, we could potentially reduce the uncertainties relating to the deposition of radioactive materials. Therefore, we should continue improving existing numerical models to more accurately represent the local circulation caused by diurnal cycle processes. This finding could also useful to improve the local depositions simulated by a global circulation model31.

Generally, local circulation is not simple because various factors, such as land use, geographical features, and synoptic wind, strongly influence the local wind field12. The findings of this study indicate that when a severe nuclear power plant accident occurs, radioactive plumes could reach faraway places via multiple diurnal cycle processes. Therefore, establishing a detailed mechanism of local circulation in every area is necessary to make any progress in reducing the uncertainties related to exposure.

Yoshikane, T. et al. Long-distance transport of radioactive plume by nocturnal local winds. Sci. Rep. 6, 36584; doi: 10.1038/srep36584 (2016).

http://www.nature.com/articles/srep36584

 

January 20, 2017 Posted by | Fukushima 2017 | , , , | Leave a comment

Local Winds Brought Radioactive Materials From Fukushima To Tokyo

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Nocturnal local winds carried radioactive material from Fukushima to Tokyo following the 2011 Fukushimia Daiichi nuclear accident.

AsianScientist (Jan. 17, 2017) – Nocturnal local winds were responsible for transporting radioactive material over 200km from the Fukushimia Daiichi nuclear accident to the Tokyo metropolitan area.

These findings by researchers from the University of Tokyo have been published in Scientific Reports. A research group led by Project Researcher Takao Yoshikane and Associate Professor Kei Yoshimura analyzed observational data and ran computer simulations to determine whether the radioactive plumes were carried by chance haphazard activity in the air or by a regular mechanism in the atmosphere. They found that the radioactive plume moves along two local wind systems that appear during the night on calm days when the impact of northwesterly seasonal winds and low-pressure systems are low. These nighttime local winds were formed by a difference in temperature between the North and the South, which created an upper layer of warm arm and a lower layer of cold air.

These findings indicate that should radioactive material be released over a long period of time, radioactive plumes could be frequently carried even to faraway places by such nocturnal local systems, and cause serious contamination in those areas.

On the other hand, the data show that it is possible to make a rough prediction of when, where, and how the radioactive plumes will travel by knowing the cycle of the winds. The current results could prove useful in determining when to seek shelter to avoid exposure to radiation.

“Stronger risk management strategies that allow for quick and cool-headed response to unforeseen situations are being sought,” said Yoshikane. “It is necessary to take into account local factors specific to each area, such as geographical features and traffic conditions.” “We hope that by expanding our study we can contribute to the development of risk management strategies through exchanges with people in other fields, government agencies, and local governments.”

The article can be found at: Yoshikane et al. (2016) Long-distance Transport of Radioactive Plume by Nocturnal Local Winds. ——— Source: University of Tokyo;

http://www.asianscientist.com/2017/01/in-the-lab/winds-radioactive-materials-fukushima-tokyo/

January 17, 2017 Posted by | Fukushima 2017 | , , | Leave a comment