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Yoshida’s Dilemma: if it wasn’t for one man, it could have been much worse

March 11, 2011. A magnitude 9 earthquake rocks Japan and triggers a mega-tsunami that kills thousands of people. It also knocks out the power at Fukushima Daiichi Nuclear Power Plant and triggers one of the worst nuclear accidents in history.
If it wasn’t for one man, it could have been much worse. 
“Rob Gilhooly has written what is probably the most comprehensive English-language account yet of the Fukushima nuclear meltdown.  Gilhooly is among the best-informed foreign reporters on this issue in Japan, having travelled to Fukushima several dozen times since being one of the first journalists to arrive in the prefecture on a freezing night in March 2011.  He gives the story of Masao Yoshida, perhaps the key figure in the disaster, all the detail, sympathy and pathos it demands.  His remarkable pictures throughout the book are a bonus.  Highly recommended. “
— David McNeil, The Economist.
“A powerful synthesis of the technical and the personal, Gilhooly succeeds in conveying the events of March 2011, its aftermath and the dramatic impact on the people of Fukushima and wider Japan. Six years after the start of the accident, Yoshida’s Dilemma is a necessary reminder of how through the actions of heroic individuals and luck Japan avoided an even greater catastrophe.”  
— S. David  Freeman, former Tennessee Valley Authority chairman, engineer, energy expert and author of Energy: The New Era and Winning Our Energy Independence
“As one of the few journalists to have covered the Fukushima story from the very start, Rob Gilhooly is perfectly placed to discuss the disaster’s causes and aftermath, and its wider ramifications for the future of nuclear power. From the chaotic scenes as the plant went into triple meltdown, to the plight of evacuated residents and Japan’s long and troubled relationship with atomic energy, Gilhooly combines fine story-telling with journalistic integrity to produce a book that is admirably free of hyperbole.” 
— Justin McCurry, The Guardian.
In Yoshida’s Dilemma, Rob Gilhooly, a long-term resident of Japan who has worked extensively as a journalist and photojournalist, has assembled a wealth of material, ranging from the reminiscences of the then Prime Minister of Japan, Naoto Kan, to the stories of those who worked to save the nation from disaster when the massive earthquake and tsunami hit the Fukushima Daiichi nuclear power plant. 
This real-life thriller concentrates on Masao Yoshida, the director of the plant, who inspired his “troops” to risk their lives as they battled the invisible enemy of radiation, but also tells of those living nearby, who were forced to give up their homes and lifestyles which had been enjoyed by their families for generations, as power companies and bureaucrats dithered and obscured the facts surrounding the worst nuclear accident since Chernobyl.
While Gilhooly is careful not to take sides in the pro- and anti-nuclear power debate, the almost inescapable conclusion is that nuclear power is a highly dangerous technology – maybe even too dangerous to be employed using the current Japanese business model, where the “nuclear village” shuts out criticism, and even knowledge, of its often dangerous operational practices and decisions. Yoshida’s Dilemma provides a wake-up call to other nations with nuclear power, whether or not they are subject to the kind of natural disaster that destroyed Fukushima, and a must-read introduction to the way in which such technology is managed and promoted, not only in Japan, but in other countries.
Main areas covered:
– The story of the nuclear crisis, as experienced by the workers at the nuclear plant, the firefighters and other emergency units who battled to bring the melting reactors under control and officials in Tokyo, such as then Prime Minister Naoto Kan, charged with responding to the disasters  
– The impact of the crisis on residents and their evacuation from their homes near the plant
– US response, including efforts by the Nuclear Regulatory Commission to cooperate with TEPCO and Japan’s nuclear watchdog, the NISA 
– Historical and cultural perspectives on nuclear power in Japan, including the launch of the Atoms For Peace expo and other efforts by the nuclear energy lobby, sometimes referred to as the “nuclear power village,” to win over the Japanese public   
– Insights from experts about technical aspects of the nuclear accident
– A look at what might have happened had the worse-case scenario played out
– Anti-nuclear protests, including efforts by communities housing nuclear facilities to prevent those facilities from being re-started
– The real cost of the disasters, including the financial burden and the health impacts uncovered 
–  An examination of the true cost of nuclear power, which was widely promoted in the US and Japan as being “too cheap to meter” 
– The future of nuclear power in Japan and nuclear power’s position in a country often perceived as being resource-poor
– The future of new energies in Japan and the nation’s increasing reliance on coal-fired power stations

April 3, 2017 Posted by | Fukushima 2017 | , , , , | Leave a comment

Fukushima Crisis Management Center


By Pierre Fetet, translation Hervé Courtois

Difficult to be innovative on the subject of Fukushima. Would we have already said everything for the last six years that the catastrophe is going on?

Well, no, with the film of Linda Bendali, “From Paris to Fukushima, the secrets of a catastrophe”, the subject of the attitude of nuclear France in March 2011 had never been approached from this angle: while Japanese Prime Minister Naoto Kan faced with nuclear fire became anti-nuclear, the Fillon government launched the heavy artillery to counter any vehemence of debate on this subject in France.

For the french Minister of Industry, Eric Besson, it was an just incident. Nicolas Sarkozy invited himself to Japan while he was not expected, to promote nuclear in the midst of the atomic crisis. And France pretended to help Japan by sending unusable or outdated products.

Therefore a good documentary pointing both Japanese and French dysfunctions that we can see in replay here again a few days.,153344813.html

And a good synthesis by Arnaud Vaulerin there.

That said, this report has awakened in me an old anger, never really extinct since 1986, and you will not escape the comments that inspires me this report.

Pierre Fetet

The lies of Tepco

At the beginning of the documentary, Tepco, champion of the lie and the unspoken is expressed by the voice of his spokesman Yuichi Okamura: “We never imagined that such an accident could happen. From the statistics, we calculated that the tsunami should not exceed 5 meters. Our forecasts were exceeded. “

He is then contradicted by the film director. I very much thank Linda Bendali for insisting that the report of the parliamentary inquiry commission on Fukushima gave as first conclusion that the Fukushima disaster was of human origin. Because few people understand the sequence of events and it is too often heard that “the Fukushima disaster was caused by the tsunami”.

Now, the real logical chain of events was this:

1) Irresponsibility: Tepco decides to build a nuclear power plant at sea level.

2) Stupidity: While seven tsunamis of 12 to 28 meters in height took place in Japan in the twentieth century, they decided to construct a protective dike of 5 m.

3) Corruption: Japan Nuclear Safety Organizations accept the construction project.

4) A natural event: a 15 m tsunami falls on the east coast of Honshu, and therefore on the Fukushima Daiichi power plant.

The IRSN is advertising its own self

The IRSN is always taken as an example and looks after its image. Normal, it is the official reference body. Yet I have already taken this institute several times in flagrante delicto of lie: Assurance that the evacuees would return within three months in 2011,

Assurance that there was no discharge of strontium and plutonium into Japan,

Assurance that a nuclear power plant cannot explode in France …

Thierry Charles even recently claimed to know where the corium is, even though Tepco itself does not know …–fukushima-tepco-evalue-peu-a-peu-l-ampleur-des-degats.php

In the documentary, the narrator assures that “IRSN is the first organization in the world to announce that the molten core has escaped from its confinement”. Indeed, listening to Jacques Repussard we get the impression that his institute communicated on this subject in March 2011.

However, six months after the catastrophe began, the IRSN still was writing: “It remains unclear whether molten fuel could be relocated to the bottom of the enclosure and in what quantity. “ (Communiqué of 25 August 2011)

Yet the Japanese government had already received a report from the IAEA on June 7 recognizing the possibility of perforations in the tanks of reactors 1 to 3 …

No seriously. The first organization that announced the me of the three cores is Tepco, on 24 May 2011. And the IRSN announced it the next day. Previously, IRSN never wrote anything else, for reactors 1, 2 and 3, that “The injection of fresh water continues. The flow rate of the water injection is adjusted in order to ensure the cooling of the core, which remains partially depleted. “

In 2011, the first person who dared to break the omerta of the nuclear lobby is Mishio Ishikawa, founder of Japan Nuclear Technology Institute (JANTI): During a Japanese TV show on April 29, 2011, he stated that the hearts of Fukushima Daiichi reactors 1, 2 and 3 were 100% melted.

That’s the story, that’s how it happened. IRSN never said that before anyone. The IRSN respected the omerta on the total meltdown of the three hearts like all the actors of the nuclear world and obediently waited for Tepco to announce the reality to acquiesce, no matter what Jacques Repussard is saying now six years later.

The Naoto Kan myth

The image of the then Prime Minister of Japan is to be nuanced. After seeing the documentary, it seems as though Naoto Kan acted as hero. It must also be admitted that he made several errors:

– Naoto Kan went to the Fukushima Daiichi plant in full crisis and greatly disturbed the ongoing management of the ongoing crisis. Director Masao Yoshida was asked to explain and explain what he was doing, wasting precious time on those who tried to solve problems one by one (It was just before the explosions of No. 2 and No. 4!). The documentary suggests that Masao Yoshida was going to leave the nuclear plant with all the workers, and that through Kan’s intervention they were forced to stay. It’s not true. Tepco may have intended to leave the ship, but the plant’s director denied any plan to abandon the site.

– The documentary shows Naoto Kan kneeling before Nicolas Sarkozy. Politeness or industrial pressures? It is not known why he did not dare to counter the French nuclear VRP.

– Naoto Kan will remain for all inhabitants of evacuated areas the one who decided to raise the standard from 1 to 20 mSv / year. On the one hand, he was ready to evacuate Tokyo, but on the other he made a whole region irradiated with a very high radiation rate. Something is bizarre in these contradictory attitudes.

The ghost of Chernobyl

Pierre Pellerin, even disappeared, is still doing damages … Between the two parts of the documentary, Frédéric Boisset, editor-in-chief of Brainworks Press, presents the story of Chernobyl in this way: “In 1986, the radioactive cloud spread throughout Europe. The authorities do not have the technical means to measure the fallout, to give instructions to the French. Can we eat fruit and vegetables? Should we caulk indoors? It was to avoid this type of failure that this institute was created [the IRSN]. “

But this is not an interview taken on the spot, it is a carefully prepared text before the recording. Frédéric Boisset therefore pretends without blushing that the SCPRI of 1986, the ancestor of the IRSN, did not have the means to alert the French of the dangers of radioactivity! What an enormity! In Germany, they had the means to prohibit the sale of spinach and salads, to confine the students inside but not in France. Frédéric Boisset refeeds us the story of the Chernobyl radioactive plume that stops at the border? It is unbelievable that still in 2017 a journalist perpetuates the disinformation lie that began in 1986.

However, the IRSN, worthy successor of SCPRI, made this statement on March 15, 2011, the day when the radioactive cloud of Fukushima arrived in Tokyo: “A slight increase in ambient radioactivity in Tokyo is noted by a few measures. This elevation is not significant in terms of radiological impact. “ Pierre Pellerin would not have said better! At the same time, Olivier Isnard, an IRSN expert sent to Tokyo, advocated caulking the premises of the French embassy. Fortunately, Philippe Faure, the French ambassador to Japan, communicated to his expatriates at 10 am: “Stay in your houses, making sure to caulk them to the maximum, this effectively protects against the low-intensity radioactive elements that could pass through Tokyo. ” But at 8 pm, he changed his tone and resumed the official speech dictated by the IRSN: “The situation remains at this time quite safe in Tokyo. A very slight increase in radioactivity was recorded. It represents no danger for human health. “ 100 Bq / m3 would pose no health hazard for a radioactive cloud coming directly from a nuclear reactor? I am feeling not any more safe than in 1986 unfortunately.

The taboo of the steam explosion

One last deception. The IRSN has purposedly mistranslated the words of Masao Yoshida, director of the Fukushima Daiichi power station. Immediately after the explosion of Unit 3, the latter, distraught, called the headquarters to inform them of the situation. Tepco released this recording and the IRSN broadcasted it in a video in 2013. I do not know Japanese but I have Japanese friends who have assured me of the translation of his words. I give you both versions, that of my friends and that of the IRSN. The people knowing japanese will be able to check for themselves.

Japan TV version IRSN version 311.jpg


The Japanese TV version :

The IRNS version :


The documentary gives another version: “HQ, HQ, it’s terrible! This is very serious ! “Yes, here HQ.” “It seems there was an explosion on reactor 3, which looks like a hydrogen explosion.” Who recommended this text to journalists? Even though Yoshida himself said “suijôki” (steam) and not “suiso” (hydrogen). The IRSN’s translation therefore censures the hypothesis put forward by the director of the nuclear plant: the steam explosion. This is normal, it is the official version of the Japanese government and the IRSN can not go against it.

The steam explosion is a taboo issue among nuclear communicators. Experts talk about it to each other, carry out studies about it, write theses about it, but never talk about it to the public because the subject of a nuclear power plant explosion is too anxiogenic. If we ever learned that a steam explosion had arrived in Fukushima, it would undermine the image of nuclear power worldwide.

In France, the political-industrial lobby has axed its communication on the control of hydrogen: All French power plants have hydrogen recombiners to avoid hydrogen explosions. But against an steam explosion, nothing can be done. When the containment vessel is full of water and the corium at 3000 ° C falls in it, it’s boom, whether in Japan or in France, whether it be a boiling water reactor or a pressurized water reactor.

Source :


February 15, 2017 Posted by | Fukushima 2017 | , , , , , | Leave a comment

Model depiction of the atmospheric flows of radioactive cesium emitted from the Fukushima Daiichi Nuclear Power Station accident


A wide area of northeastern Japan, the Tohoku and Kantou regions, was contaminated by the radioactive material emitted from the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS) of the Tokyo Electric Power Company (TEPCO), as manifested by various environmental investigations (Nakajima et al. 2014). The accident was caused by the Great East Japan Earthquake, which struck at 14:46 Japan Standard Time (JST; Coordinated Universal Time, UTC+ 9 h) on 11 March 2011.

Takemura et al. (2011) show that the negative anomaly of a 500-hPa height over the Okhotsk Sea area along 145° E made the westerly jet stronger than the climatological mean during mid-March; consequently, 70 to 80% of the radioactive material from the FDNPS was driven to the Pacific Ocean and the rest of the globe (Takemura et al. 2011; Stohl et al. 2012; Mészáros et al. 2016). The remaining material spread over and deposited onto the land area of Japan, producing characteristic hot spot patterns (Yasunari et al. 2011; JAEA 2012; SCJ 2014). The total emission of 137Cs into the atmosphere until the end of April was estimated to be 14.6 ± 3.5 PBq (SCJ 2014). The ratio of the total deposition over the Japanese land area to the total atmospheric emission was estimated as 20 ± 6%, according to the airborne monitoring conducted by the Ministry of Education, Culture, Sports, Science, and Technology, Japan (MEXT 2011), whereas the ratio was calculated as 27 ± 10% based on the multi-model intercomparison by the Science Council of Japan (SCJ 2014). To date, this inconsistency has not been fully understood, owing to the lack of observation data, which is attributable to instrumental damage and electric outages as well as modeling uncertainties. In addition, there is still great uncertainty in the emission time series of the radioactive material, as shown in Fig. 1. Yumimoto et al. (2016) conducted an inverse analysis to optimally estimate the emission rate using the time series of the deposition map, but the result is very different from that of Katata et al. (2015).

Time series of the 137Cs emission rate from the FDNPS, as estimated by Terada et al. (2012), Katata et al. (2015), and Yumimoto et al. (2016)


Recently, Tsuruta et al. (2014) developed a method to directly measure the hourly time series of the atmospheric 137Cs concentration at surface level, from the aerosol sampling tapes of the national suspended particulate matter (SPM) network. The SPM network monitors air pollution by employing beta-ray attenuation counters. Four laboratories, namely, those of Tokyo Metropolitan University, the Nuclear Professional School of the University of Tokyo, the Japan Atomic Energy Agency, and the Japan Chemical Analysis Center, retrieved the atmospheric loading from the hourly aerosol spots on the SPM tape. This method offers the potential for studying the atmospheric transport of 137Cs, although the data is from surface level, during the entire post-accident period; the SPM dataset has high temporal and spatial sampling, with observations every hour at 90 out of 400 sites (Fig. 2). In Fig. 2, it can be seen that the Nakadori region is a channel basin area between the Ou and Abukuma mountains, while the Hamadori region is a coastal region to the east of the Abukuma mountains. The FDNPS is located in the northern part of the Hamadori region. In this report, we compare the ensemble results of two aerosol transport models with SPM data. An important purpose of the comparison is to investigate the validity of the combined use of SPM data and multi-model simulations to depict the transportation of atmospheric 137Cs over the Japan land area. Once validated, further analysis can be performed on a larger volume of SPM data, such as the most recent data from 99 SPM sites, which has recently been made available to the public (Oura et al. 2015). In addition, the results could be a useful input for our second model intercomparison, which is intended as a follow-up to the first comparison, which was made by the SCJ (SCJ 2014), and this can contribute to future discussions of the use of models in emergency protocols.

jan 23 2017.jpg

Names of key regions and locations of SPM sites at the time of accident for the present study. The Tohoku region is the northeastern part of the Japanese islands and includes the Fukushima and Miyagi prefectures; the Kantou region is the area that includes the Tokyo, Saitama, Chiba, Kanagawa, and Ibaraki prefectures. The FDNPS is located in the northern part of the Hamadori region, a coastal area to the east of the Abukuma Mountains. The Nakadori region is a channel basin area between the Ou and the Abukuma mountains. Open circles are SPM monitoring sites managed and maintained by local governments in eastern Japan before the accident. The base map was modified by using the original map in Fig. 1 of Tsuruta et al. (2014)


Tsuruta et al. (2014) identified nine plumes, as listed in Fig. 3, that transported particulates to the land area of Japan and in which the maximum atmospheric 137Cs concentration exceeded 10 Bq m−3, based on a synoptic analysis using a time series of the SPM data and the wind vector field. For purposes of comparison, we selected plumes P2 to P9 in the period 14–24 March 2011. In this period, there were two migrations of low pressure systems over Japan; these occurred on 15 and 20 March, according to the weather maps shown in Fig. 4.


Plumes identified by Tsuruta et al. (2014). Horizontal bars show the period with high 137Cs concentrations (>10 Bq m−3). Closed and open circles indicate areas in the Hamadori, Nakadori, and Kantou regions where the concentrations were larger or smaller, respectively, than 100 Bq m−2


jan 23 2017 wind direction 311.jpg

af Weather maps based on JMA analysis at 9:00 JST in the analysis period


To read more:





February 9, 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


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.


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.


(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 ( (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.


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.


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 (


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.


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 (



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.


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 ( 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).


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

Records of Diet’s Fukushima investigation still under wraps


Kiyoshi Kurokawa, chairman of the Fukushima Nuclear Accident Independent Investigation Commission, presents the final report to Lower House Speaker Takahiro Yokomichi, right, in July 2012.

Five years after the accident at the Fukushima No. 1 nuclear power plant, the Diet is still sitting on a trove of raw documents and testimonies of more than 1,100 individuals who were on the front lines during the crisis.

The cache was compiled by the Fukushima Nuclear Accident Independent Investigation Commission, which released a report of its findings that totaled about 600 pages in July 2012.

The documents collected by that commission, including the testimonies of 1,167 individuals, have still not been released to the public more than four years after its disbandment.

Yasunori Sone, a political science professor at Tokyo’s Keio University, said the documents should, in principle, be released to the public because the investigation was conducted by the Diet on behalf of the people.

“The Fukushima Nuclear Accident Independent Investigation Commission was the first established in the Diet with the authority to carry out a thorough investigation,” Sone said. “Disclosure rules should be decided on quickly because it will serve as a precedent for future commissions.”

However, the documents submitted to the commission by the central government as well as Tokyo Electric Power Co., operator of the Fukushima plant, remain in storage at the National Diet Library, along with more than 900 hours of questioning of the 1,167 individuals, many of whom worked to bring the accident under control.

Some of the testimony was given on condition that it would not be released.

For that reason, after the commission disbanded, the rules and administration committees of the two chambers of the Diet were to have established rules for disclosing the commission records.

The commission had left behind a record of its investigation as well as the source of the documents it had accumulated because it felt that it would be helpful when the documents were eventually released.

“It will be possible to learn about the background to the nuclear accident from new reports or books that are written based on the documents,” said Kiyoshi Kurokawa, a professor emeritus at the University of Tokyo, who chaired the commission. “A fundamental point to not repeating mistakes is to learn from one’s past errors.”

Discussions within the rules and administration committees were disrupted when then Prime Minister Yoshihiko Noda dissolved the Lower House in November 2012 and called a snap election.

The December election brought the Liberal Democratic Party and its junior coalition partner, Komeito, back in control of government.

A multiparty group of lawmakers who were seeking to end dependence on nuclear energy asked that the rules and administration committees resume work on establishing disclosure rules. However, a subcommittee held one session that focused on presenting the opinions of members.

“Both the ruling and opposition parties are hesitant about releasing the documents because there is the possibility that they contain contents that are disadvantageous to the LDP, which had pushed nuclear energy, and the then Democratic Party of Japan, which had to deal with the nuclear accident,” said a member of that multiparty group.

The disclosure of the documents is not the only area in which the Diet has been less than aggressive.

In its report, the commission included seven recommendations, including the establishment of a new independent investigation committee, made up mainly of experts from the private sector, to conduct further studies into unanswered questions about the accident.

However, the rules and administration committees have yet to discuss the possibility of establishing such an investigative committee.

The commission also recommended the establishment of special committees in both chambers of the Diet to oversee the nuclear regulatory structure.

In 2013, a Special Committee for Investigation of Nuclear Power Issues was established separately in the two chambers.

However, those special committees have been turned into venues to promote nuclear energy. For example, committee members who were originally from labor unions of the electric power companies or who represented districts where nuclear plants were based criticized the Nuclear Regulation Authority for its strict standards regarding the resumption of operations at nuclear plants.

In a similar manner, the special committees also asked for a review of the rule that limited nuclear plants to a maximum 40-year operating life.

Tomoko Abe, a Democratic Party member who serves as secretary-general of the multiparty group seeking zero nuclear power generation, said, “Although there are some issues regarding the nuclear accident that have become clearer with the passage of time, the arena for looking into those issues has been closed off. It is the responsibility of the legislative branch to set up a structure that will continue to examine the nuclear accident.”

September 26, 2016 Posted by | Fukushima 2016 | , , , | Leave a comment

Protesters rally in front of PM office, Diet calling for end to nuclear power


Demonstrators in front of the prime minister’s office in Tokyo’s Chiyoda Ward offer a silent prayer to those who died in the March 2011 Great East Japan Earthquake and tsunami, on March 11, 2016.

Protesters rally in front of PM office, Diet calling for end to nuclear power

Protestors staged demonstrations in front of the prime minister’s office and the Diet in Tokyo on March 11, calling for the elimination of nuclear power.

Demonstrators chanted slogans including, “Don’t restart nuclear reactors,” and, “Protect Fukushima.” Some 6,000 people participated in the demonstrations, according to the organizer, the Metropolitan Coalition against Nukes.

Psychiatrist Rika Kayama said during a rally in front of the National Diet Building, “I’d like to join hands with you in blocking reactivation of nuclear plants across the country.”

Takeshi Suwahara, a key member of the Students Emergency Action for Liberal Democracy (SEALDs), said, “I don’t want to rely on a power generation method that could cost people their lives and livelihoods.”

Toshima Ward, Tokyo resident Akira Suzuki, 66, stated Japan “should switch to natural, renewable energy sources since we’ve learned lessons from the Fukushima (nuclear) accident.”


Participants call for a nuclear-free society during a rally held in front of the Diet building in Tokyo on March 11.

Anti-nuclear rally in Tokyo marks 187th since the 2011 disaster

Thousands of anti-nuclear activists rallied around the prime minister’s office and the Diet building in Tokyo on March 11, the fifth anniversary of the earthquake and tsunami disaster that triggered the nuclear crisis in Fukushima Prefecture.

The Metropolitan Coalition Against Nukes, a citizens group that organized the protest, estimated that 6,000 or so people took part.

Participants raised slogans against the restart of nuclear reactors and the lingering effects of the triple meltdown at the Fukushima No. 1 nuclear power plant caused by the magnitude-9.0 Great East Japan Earthquake and tsunami.

The activists have rallied on Friday nights since the nuclear accident. The latest gathering was the 187th.

“I intend to continue to express my opinions in order to create a society that does not depend on nuclear power generation,” said Moeko Mizoi, 20, a sophomore of Tsuda College, whose grandparents live in Fukushima Prefecture.

In a related development, former Prime Minister Junichiro Koizumi gave a speech in an event held in Tokyo on March 11 for the screening of a documentary movie, “Nihon to Genpatsu Yonengo” (Japan and nuclear power generation, four years later).

“I want people to continue their anti-nuclear movement with patience so that the Japanese economy can develop without nuclear power generation,” Koizumi said.

“People’s voices will change politics,” he added.


Hiroshima atomic bombing survivor So Horie, second from right in the front row, and other plaintiffs head to the Hiroshima District Court on March 11, 2016. The banner they are holding reads “Atomic bombed Hiroshima refuses radiation exposure” and “Things past cannot be changed, but we can change our future.”

A-bomb survivors demand court shut western Japan nuclear plant

HIROSHIMA (Kyodo) — Plaintiffs including survivors of the 1945 U.S. atomic bombings filed a lawsuit Friday with a court demanding a halt to operation of Shikoku Electric Power Co.’s Ikata nuclear plant in western Japan.

They brought the suit to the Hiroshima District Court, arguing that the environment would be devastated and their health affected if an accident similar to the 2011 Fukushima disaster takes place at the plant in Ehime Prefecture, their lawyers said.

Friday is the fifth anniversary of a major earthquake and tsunami that triggered the accident at the Fukushima Daiichi plant of Tokyo Electric Power Co.

The three reactors at the Ikata plant are currently off-line but Shikoku Electric envisions rebooting the No. 3 unit in the spring or later. The reactor cleared a safety screening last July.

The plaintiffs are a group of 67 people, including 18 survivors of the Hiroshima and Nagasaki bombings and one Fukushima evacuee living in Hiroshima Prefecture.

Three of the plaintiffs are also seeking an injunction ordering the No. 3 unit not to be restarted ahead of the court’s final ruling, according to the lawyers.

The litigation came two days after another Japanese court issued an injunction ordering two reactivated reactors at Takahama plant of Kansai Electric Power Co. to be halted as requested by a group of local residents.

In the injunction, the Otsu District Court cited “problematic points” in planned responses for major accidents and “questions” on tsunami countermeasures and evacuation planning.

All Japan’s reactors were taken off-line following the Fukushima disaster but four reactors, including the two Takahama units, have been reactivated since last year under stricter post-Fukushima safety regulations.

March 12, 2016 Posted by | Japan | , , | Leave a comment