As a farmer, Atsuo Tanizaki did not care much for the state’s maps of radioactive contamination. Colour-coded zoning restrictions might make sense for government workers, he told me, but ‘real’ people did not experience their environment through shades of red, orange and green. Instead, they navigated the landscape one field, one tree, one measurement at a time. ‘Case by case,’ he said, grimly, as he guided me along the narrow paths that separated his rice fields, on the outskirts of a small village in Japan’s Fukushima prefecture.

It was spring in 2016 when I first visited Tanizaki’s farm. The air was warm. The nearby mountains were thick with emerald forests of Japanese cedar, konara oak and hinoki cypress. A troop of wild red-faced monkeys stopped foraging to watch us as we walked by. And woven through it all – air, water, land, plants, and living bodies – were unseen radioactive pollutants. Almost everything now carried invisible traces of the 2011 meltdown at the Fukushima Daiichi nuclear power plant.

Continue reading at aeon.co

On March 11, 2011, Koide Hiroaki was in his laboratory in Kyoto, Japan. It was a gray, wet afternoon, and the 61-year-old nuclear engineer was hard at work when the earthquake hit. Fifteen miles beneath the surface of the sea, one tectonic plate rumbled beneath another. A slippery clay layer helped the great pieces of crust slide, releasing centuries of stress. The seabed rose up 16 stories, and slipped sideways 165 feet.

Read the rest at National Geographic

The archival record makes clear that killing large numbers of civilians was the primary purpose of the atomic bombing of Hiroshima; destruction of military targets and war industry was a secondary goal and one that “legitimized” the intentional destruction of a city in the minds of some participants. The atomic bomb was detonated over the center of Hiroshima. More than 70,000 men, women, and children were killed immediately; the munitions factories on the periphery of the city were left largely unscathed. Such a nuclear attack would be illegal today. It would violate three major requirements of the law of armed conflict codified in Additional Protocol I of the Geneva Conventions: the principles of distinction, proportionality, and precaution. There could be great pressure to use nuclear weapons in future scenarios in which many American soldiers’ lives are at risk and there is no guarantee that a future US president would follow the law of armed conflict. That is why the United States needs senior military officers who fully understand the law and demand compliance and presidents who care about law and justice in war.

Read the rest at Bulletin of Atomic Scientists

On the quiet Friday afternoon of March 11, 2011, Natsuo* was working in Fukushima, the capital city of Fukushima prefecture. At 2:46 p.m., a devastating earthquake of 9.0 magnitude hit the Pacific coast of Japan, where the prefecture of Fukushima is situated. Natsuo recalled to me the sheer power of this earthquake: “The whole office shook like hell, everything began to fall from the walls. I thought to myself ‘That’s it … I’m going to die!’”

Natsuo quickly returned to her hometown of Koriyama City, unaware that the earthquake had triggered a massive tsunami, which inundated an important part of the prefectural shoreline and ultimately claimed the lives of nearly 20,000 people. On top of the initial devastation, the tsunami severely damaged the Fukushima Dai’ichi Nuclear Power Plant, in Ōkuma, Fukushima, located on the east coast of Fukushima prefecture. She later learned on TV that something “seemed wrong” with the nuclear power plant. “During that time,” she said, “I tried to get as much information as I could, but the media weren’t being clear on the situation.”

Read the rest at Sapiens

Nearly ten years after meltdown at the Fukushima Daiichi Nuclear Power Plant caused a nuclear disaster, researchers have uncovered important new information about the extent and severity of the meltdown and the distribution patterns of the plutonium that have broad implications for understanding the mobility of plutonium during a nuclear accident.

According to a paper published July 8 in Science of the Total Environment, microscopic particles emitted during the disaster contained not only high concentrations of radioactive cesium, as previously reported, but also the toxic metal plutonium. These microscopic radioactive particles formed inside the Fukushima reactors when the melting nuclear fuel interacted with the reactor’s structural concrete.

“The study used an extraordinary array of analytical techniques in order to complete the description of the particles at the atomic-scale,” said Rod Ewing, co-director of the Center for International Security and Cooperation (CISAC) at Stanford University.

Ewing collaborated with researchers from Kyushu University, University of Tsukuba, Tokyo Institute of Technology, National Institute of Polar Research, University of Helsinki, Paul Scherrer Institute, Diamond Light Source and SUBATECH (IMT Atlantique, CNRS, University of Nantes).

The researchers found that, due to loss of containment in the reactors, the particles were released into the atmosphere and many were then deposited many kilometers from the reactor sites. Studies have shown that the cesium-rich microparticles, or CsMPs, are highly radioactive and primarily composed of glass (with silica from concrete) and radio-cesium (a volatile fission product formed in the reactors). But the environmental impact and their distribution is still an active subject of research and debate. The new work offers a much-needed insight into the Fukushima Daiichi Nuclear Power Plant, (FDNPP) meltdowns.

Geochemist Satoshi Utsunomiya and graduate student Eitaro Kurihara of Kyushu University led the team that used a combination of advanced analytical techniques, including synchrotron-based micro-X-ray analysis, secondary ion mass spectrometry, and high-resolution transmission electron microscopy, to find and characterize the plutonium that was present in the CsMP samples. The researchers initially discovered incredibly small uranium-dioxide inclusions, of less than 10 nanometers in diameter, inside the CsMPs; this indicated possible inclusion of nuclear fuel inside the particles.

Detailed analysis revealed, for the first-time, that plutonium-oxide concentrates were associated with the uranium, and that the isotopic composition of the uranium and plutonium matched that calculated for the FDNPP irradiated fuel inventory.

“These results strongly suggest that the nano-scale heterogeneity that is common in normal nuclear fuels is still present in the fuel debris that remains inside the site’s damaged reactors,” said Utsunomiya. “This is important information as it tells us about the extent [and] severity of the meltdown. Further, this is important information for the eventual decommissioning of the damaged reactors and the long-term management of their wastes.”

With regards to environmental impact, Utsunomiya said, “as we already know that the CsMPs were distributed over a wide region in Japan, small amounts of plutonium were likely dispersed in the same way.”

Gareth T. W. Law, a co-author on the paper from the University of Helsinki, said the team “will continue to experiment with the CsMPs, in an effort to better understand their long-term behavior and environmental impact. It is now clear that CsMPs are an important vector of radioactive contamination from nuclear accidents.”

Bernd Grambow, a coauthor from Nantes/France, said, “While the plutonium released from the damaged reactors is low compared to that of cesium; the investigation provides crucial information for studying the associated health impact.”

Utsunomiya emphasized that this is a great achievement of international collaboration. “It’s been almost ten years since the nuclear disaster at Fukushima,” he said, “but research on Fukushima’s environmental impact and its decommissioning are a long way from being over.”

Ewing is also the Frank Stanton Professor in Nuclear Security, a Senior Fellow of the Precourt Institute for Energy, Senior Fellow at the Freeman Spoglie Institute for International Studies and. Professor of Geological Sciences in Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth). Co-authors of the paper include Eitaro Kurihara, Masato Takehara, Mizuki Suetake, Ryohei Ikehara, Tatsuki Komiya, Kazuya Morooka, Ryu Takami, Shinya Yamasaki, Toshihiko Ohnuki, Kenji Horie, Mami Takehara, Gareth T. W. Law, William Bower, J. Frederick. W. Mosselmans, Peter Warnicke, Bernd Grambow, Rodney C. Ewing, and Satoshi Utsunomiya

Integration of analytical techniques was accomplished through an international network that included Kyushu University, University of Tsukuba, Tokyo Institute of Technology, National Institute of Polar Research, University of Helsinki, Paul Scherrer Institute, Diamond Light Source, SUBATECH (IMT Atlantique, CNRS, University of Nantes) and Stanford University.  

This article was adapted from a press release produced by Kyushu University.

Read Particulate plutonium released from the Fukushima Daiichi meltdowns

Media contacts:

Josie Garthwaite

School of Earth, Energy & Environmental Sciences

(650)497-0949, josieg@stanford.edu

Jody Berger

Center for International Security and Cooperation

(303)748-9657, jody.berger@stanford.edu

This article examines a set of public controversies surrounding the role of nuclear power and the threat of radioactive contamination in a post-Fukushima Japan. The empirical case study focuses on the Ministry of Economy, Trade and Industry (METI), Japan most influential ministry and, more importantly, the former regulator of nuclear energy before the 2011 Fukushima nuclear disaster. Through participant observation of METI’s public conferences, as well as interviews with state and non-state actors, I examine how particular visions of nuclear power continue to affect the basis of expert authority through which state actors handle post-Fukushima controversies and their subsequent uncertainties. In its post-Fukushima representations, METI frames nuclear power as an apolitical necessity for the well-being of the Japanese nation-state and the common humanity. It does so by mobilizing categories of uncertainty around specific political scenes, such as global warming. For METI, the potential uncertainties linked with the abandonment of nuclear power have the power to trigger political turmoil of a higher scale than those linked with Fukushima’s radioactive contamination. A form of double depoliticization takes place, in which the issue of Fukushima’s radioactive contamination gets depoliticized through perceived priorities that are paradoxically depicted as ‘post-political’ – that is, in an urgent need for immediate action and not open to in-depth deliberation. I refer to this process as establishing ‘post-political uncertainties’. This kind of depoliticization raises ethical questions surrounding meaningful public participation in decisions that happen at the intersection of politics and science and technology study.

Read the rest at Social Studies of Science

This piece originally appeared at Safecast.

Image

Image above: Secondary 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. Via Safecast

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

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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

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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

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

Yamaguchi et al., 2016

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

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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

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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

https://link.springer.com/chapter/10.1007/978-4-431-55848-4_19

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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

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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

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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

https://www.nature.com/articles/s41598-017-05910-z

—————————————————————-

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

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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

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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