Since the release of the information notes on April 7, 15 and 17, 2020, the number of fires in Ukraine has decreased. As of April 24, 2020, however, a few outbursts remain in the exclusion zone around the Chernobyl power plant.

IRSN new information report updates the previous situation points by setting out the state of the fires to date and by updating trajectories of the fire-contaminated air masses.

As promised, IRSN publishes the results of its first measurements, which notably concern the airborne 137Cs activity in France of 137Cs-labeled air masses from the fire area. These measurements show very tiny levels of radioactivity, consistent with its modeling results.

Download the IRSN information note of 24 April 2020: Fires in Ukraine in the exclusion zone around the Chernobyl power plant: First results of 137Cs me​asurements in France

Modeling of the dispersio​n in Europe of the air masses from the fires in the Chernobyl region: version of April 24, 2020

The fires in Ukraine, which had been announced extinguished on April 15, 2020, were reactivated under the effect of strong winds which stirred up the embers of previous fires.

On April 17, 2020, IRSN produced a new information report explaining the evolution of the fires compared to the situation presented on April 15, 2020, and specifying some elements relating to the nuclear installations located on the site of the Chernobyl NPP.

Download the IRSN information note of 17 April 2020: Fires in Ukraine in the exclusion zone around the Chernobyl power station: Situation report

Modeling of the dispersio​n in Europe of the air masses from the fires in the Chernobyl region: version of April 17, 2020

This update presents a new version of the modeling of the air mass trajectories from the fire area and now covers the period from 3 to 20 April 2020.

The red triangle represents the l​ocation of the fires, the time is in UTC.

The radioactive release used was evaluated by reverse modeling (use of available measurements). This simulation was performed on the assumption that the average radioactive releases, which occurred between April 3 and 12, 2020, will continue from April 14 to 20, 2020.

Since IRSN information report of April 7, 2020 (read in French), the fires in Ukraine have spread to reach the environment near the Chernobyl plan​t. According to the Ukrainian authorities, these fires are now under control.

IRSN publishes a new information report which provides an assessment of the possible radiological impacts for the responders as well as for the inhabitants of Kiev. It also takes stock of the levels of activity in the air likely to be detected in France due to the transport of air masses contaminated by these fires.

Download IRSN information report of April 15,2020: Fires in Ukraine in the exclusion zone around the Chernobyl power plant

Modeling of the dispersio​n in Europe of the air masses from the fires in the Chernobyl region: version of April 15, 2020

IRSN has performed a modeling estimation of the amount of radioactivity re-emitted by fires, and a modeling of the plume dispersion over Europe.

The radioactive release used was evaluated by reverse modeling (use of available measurements) over the period from April 3 to 12, 2020, the dispersion simulation continues until April 14, 2020.

Result of the French-Japanese research project Shinrai, the report "The 3/11 accident and its social consequences - Case studies in Fukushima prefecture" analyses post accidental policy in Fukushima prefecture, particularly the questions linked to return or non-return to evacuated towns and villages. The report also compares the concrete experience of the inhabitants and the decision-makers with a number of principles that underlies international post accidental policy and recommendations.​

Download IRSN Report 2019/00178: Shinrai research Project: The 3/11 accident and its social consequences. Case studies from Fukushima prefecture

Eight years after the Fukushima Daiichi nuclear accident in Japan, IRSN publishes a report on its social consequences. This research is based on an intensive field work carried out by researchers with inhabitants of the Fukushima prefecture. The Institute investigates this topic within the framework of the Shinrai project​, a French-Japanese research program coordinated by IRSN with the participation of Sciences Po Paris and To​kyo Tech.

The framework of this research is inscribed in the field of disaster studies, with a multidisciplinary approach (anthropology, political sciences, sociology) in order to analyze the trust of Japanese citizens towards the government in charge of dealing with the crisis. Between 2014 and 2017, researchers from IRSN and Sciences Po completed 118 interviews during 8 missions of 2 to 3 weeks:​

• ​​​Inhabitants of the Watari quarter in Fukushima city (60 km from t​he crippled Fukushima Daiichi nuclear power plant), the town of Naraha and the village of Kawauchi, who were allowed to return or not to their hometown after the lifting of evacuation orders (EOs) by the Japanese government (see interactive map below),
• Government and local representatives to better understand the policy of lifting of EOs after decontamination,
• ​Non-Profit Organizations (NPOs) or independent experts, who played an important role in informing and supporting the population.

Despite decontamination and the lifting of EOs, the rate of returnees is relatively low. The fieldwork identified six broad categories of inhabitants in relation to their decision to “whether return or not” after the lifting of EOs. This categorization shows the diversity of situations, depending on age, family status - for example, family with children -, commitment to the post accidental policies, confidence in the assessment of radiological situation by government experts.

​​The research highlights the role of local elected representatives, in this case the mayors, by showing how they sought to meet both government requirements and the wishes of their constituents. It also addresses the ethical dilemmas that politicians, authorities and government experts have faced: is it legitimate to reassure the population at all costs? How to decide when the interests of the inhabitants question the notion of "community" conceptualized as a homogeneous set of persons? 

The report concludes by comparing co​ncrete situation in Fukushima with a number of principles that underlies international post accidental policy and recommendations. This report identified three ways to fuel the reflections in the French and international bodies in charge of managing the post accidental phase:

• ​The attachment of the inhabitants to their hometown, observed after the Chernobyl accident, was not verified in Fukushima. However, this is an assumption underlying post accidental policy, as noted in Publication 111 of ICRP, the international body responsible for radioprotection recommendations. The decision of the Japanese government to "reconquer" the territories by entrusting their decontamination to private companies is appreciated by those who wish to return, but denounced by those who would have preferred that the money be invested otherwise (allowing a final relocation for example).
• The commensurability of radiological risk with other risks (tobacco, alcohol or natural risks specific to Japan). This rationale is recurrent in the discourses of radiological protection but shows some limitations in the aftermath of the Fukushima nuclear accident. While this principle is acceptable to some inhabitants, it is radically dismissed by others, who cannot put in balance the health of their children or accept this​ “balanced” approach.
• The designation of zones as a tool for radiation protection of populations. This pillar of Japanese post accidental policy was based on the international regulation and recommendation framework established by ICRP and IAEA. However, zoning choices have been questioned, including their definition based on the level of radioactivity measured or estimated for the future.​​​

Download IRSN Report 2019/00178: Shinrai research Project: The 3/11 accident and its social consequences. Case studies from Fukushima prefecture

​About the Shinrai project

​Shinrai ("confidence", in Japanese) is a French-Japanese research project started in 2014. Led by IRSN with the participation of Sciences Po Paris and Tokyo Tech, it aims to investigate the decision making methods used by authorities following the accident and their impact on the population.

The project studies the role of public authorities, their trustworthiness (ability to meet the confidence of citizens) and their accountability (ability to account to their own decisions), including in a context when scientific data alone do not allow to proceed and legitimize decisions.

Along with their NEA peers, a number of IRSN experts will contribute actively to three projects to prepare for the decommissioning of the damaged Fukushima Daiichi reactors: one project to prepare the recovery and analysis of fuel debris (PreADES PreADES [http://www.oecd-nea.org/jointproj/preades.html]), another to examine the state of the damaged reactors (ARC-F) in more detail, and another to thermodynamically characterize the fuel debris and fission products (TCOFF).

IRSN intends to share its expertise internationally: by contributing to the synthesis of knowledge acquired from the Fukushima Daiichi accident, by contributing its expertise to the analysis of debris samples from the damaged reactors, by upgrading its thermodynamic databases (NUCLEA, MEPHISTA).

IRSN expects that its participation in these three projects will help to strengthen its expertise capacity on severe accidents: it will gain a better understanding of the limits of the various tools and methods it has developed through its studies and research, by applying them to the reality of an accident that has been thoroughly analyzed.

The epidemiological study EPICE provides well-documented answers regarding non-cancerous radiation-induced effects. This study does not observe an association between cardiac arrhythmia and caesium-137 deposition levels on children living in the Bryansk region exposed to Chenobyl fallout.

The scientific evidence currently available about the possible health consequences of accidental exposure to ionizing radiation is mainly based on lessons learned from the follow-up of A-bomb survivors (Hiroshima and Nagasaki) in Japan, as well as populations exposed to fallout from the Chernobyl accident in Belarus, Ukraine and Russia. The observed effects vary according to the type of radiation exposure, dose rate and study population.

In the long term (a few years to decades), an increase in the risk of leukemia and cancers has been observed among the Japanese survivors of the Hiroshima and Nagasaki bombings, as well as an increase of thyroid cancer in children exposed to fallout from the Chernobyl accident in Belarus, Ukraine and Russia.

With respect to non-cancerous effects, a relationship between the risk of cardiovascular disease and exposure to ionizing radiation was observed in the survivors of the Hiroshima and Nagasaki bombings and in Chernobyl liquidators; a similar observation was made for lens opacities (early stage of cataract) and exposure. However major uncertainties remain over the existence of such low-dose associations.

To address this issue, IRSN set up in 2005 the EPICE program (Evaluation of Pathologies potentially Induced by chronic CEsium contamination) in order to gather scientific information on non-cancerous effects resulting from chronic low-dose ionizing exposures and to answer a societal question relating to the health consequences of the Chernobyl nuclear accident in a sensitive population (children).

All of these medical examinations diagnosed 2,526 children with cardiac arrhythmia. As a result of a thorough statistical analysis of the data collected on the field, over the period 2009-2013, the prevalence of cardiac arrhythmias estimated in the contaminated territories is significantly lower than in the controlled territories. With regard to caesium-137 whole-body burden, no association could be demonstrated. Therefore, caesium-137 is not an associated factor in the occurrence of cardiac arrhythmia in the frame of the study.

This epidemiological study, which is unique in terms of its size and the quantity of data collected, thus provides well-documented answers regarding non-cancerous radiation-induced effects in children living in Russian contaminated territories by the fallout from the Chernobyl accident, issue which is widely discussed for many years.

This article, published in BMJ Open (open access version of the prestigious journal The British Medical Journal), is the first in a series of future publications on the results of the EPICE program, including the conclusions of a study on a large-scale screening of lens opacities in a similar group of children living in the same region of Russia.

Download the article published in BMJ Open “Is exposure to ionising radiation associated with childhood cardiac arrhythmia in the Russian territories contaminated by the Chernobyl fallout? A cross-sectional population-based study” (PDF, 408 Ko)

IRSN publishes a new report that summarizes the various investigations it conducted following the detection in October 2017 of Ruthenium 106 in France and Europe.

This report was presented by IRSN on January 31, 2018 in Moscow (Russia) on the occasion of the first meeting of the International Commission of Experts set up by the Russian authorities, dedicated to the examination of the origin of Ruthenium 106.

Download IRSN information report of February 6, 2018: Detection in October 2017 of Ruthenium 106 in France and in Europe : Results of IRSN’s investigations - Update of information report of November 9, 2017

Download IRSN report of January 2018: Report on the IRSN’s investigations following the widespread detection of Ruthenium 106 in Europe early October 2017

Ruthenium-106 has been detected in late September 2017 by several European networks involved in the monitoring of atmospheric radioactive contamination, at levels of a few milliBecquerels per cubic meter of air. IRSN's investigations make it possible to provide information on the possible location of the source of the release as well as the order of magnitude of the quantities released.

As soon as it became aware of the first detections of Ruthenium-106 in the atmosphere in Europe, IRSN mobilized all its means of radiological monitoring of the atmosphere and conducted regular analysis of the filters from its monitoring stations. For the period from September 27 to October 13, 2017, only the stations of Seyne-sur-Mer, Nice and Ajaccio revealed the presence of Ruthenium-106 in trace amounts. Since October 13, 2017, Ruthenium-106 is no longer detected in France.

Measurement results from European stations communicated to the Institute since October 3, 2017, have confirmed the presence of Ruthenium-106 in the atmosphere of the majority of European countries. The results obtained for sampling periods later than October 6, 2017, showed a steady decrease in Ruthenium-106 levels, which is currently no longer detected in Europe.

The concentration levels of Ruthenium-106 in the air that have been recorded in Europe and especially in France are of no consequence for human health and for the environment.

Based on the meteorological conditions provided by Météo France and the measurement results available in European countries, IRSN carried out simulations to locate the release zone, to assess the quantity of ruthenium released, as well as the period and the duration of the release.

The map below summarizes the results obtained and confirms that the most plausible zone of release lies between the Volga and the Urals without it being possible, with the available data, to specify the exact location of the point of release. Indeed, it is in this geographical area that the simulation of a ruthenium release makes it possible to better reproduce the measurements obtained in Europe.

For the most plausible zone of release, the quantity of Ruthenium-106 released estimated by IRSN simulations is very important, between 100 and 300 teraBecquerels. The release, accidental with regard to the quantity released, would have occurred during the last week of September 2017.

Because of the quantities released, the consequences of an accident of this magnitude in France would have required to implement locally measures of protection of the populations on a radius of the order of a few kilometres around the location of the release.

For foodstuffs, the exceeding of maximum permitted levels (1250 Bq/kg for Ruthenium-106 for non-milk products) would be observed over distances of the order of a few tens of kilometres around the location of the release.

The possibility of exceeding maximum permitted levels near the accident site led IRSN to study the scenario of importing foodstuffs from this area. From this analysis, IRSN considers, on the one hand, that the probability of a scenario that would see the importation into France of foodstuffs (especially mushrooms) contaminated by Ruthenium-106 near the source of the release is extremely low and, on the other hand, the potential health risk associated with this scenario is also very low. It does not therefore appear necessary to introduce systematic controls on the contamination of imported foods.

Download IRSN information report from Novembre 9, 2017: Detection of Ruthenium-106 in France and in Europe: Results of IRSN’s investigations

Ruthenium-106 [1] has been detected by several European networks involved in the monitoring of atmospheric radioactive contamination, at levels of a few milliBecquerels per cubic meter of air.

IRSN has therefore undertaken investigations since October 3, 2017 to carry out an in-depth assessment of the measurements of ruthenium levels in the territory and to identify the possible origins of the situation encountered.

In France, IRSN has mobilized all its measurement stations for atmospheric monitoring and undertook the analysis of their filter samples [2]. At this stage, only the filters of the stations of Seyne-sur-Mer (Var) and Nice (Alpes-Maritimes) show the presence of ruthenium-106 at trace levels (respectively 7.4 and 6.8 micro-Bq/m³). The results of measurement of the filters of the other stations of IRSN do not show the presence of this radionuclide. All the measurement results are shown in the table 1 below.

Based on calculations carried out by IRSN, the levels of atmospheric contamination with ruthenium-106 of the order of those observed in Europe are not likely to generate health effects.

By combining levels of contamination observed and numerical simulations performed by IRSN, it appears that the contaminated air masses measured in Europe originate from the southern regions of the Urals. Given the amount of ruthenium-106 that may be at the origin of the air pollution observed in Europe, it appears that measures of protection of the populations could have been necessary in the vicinity of the site of the releases. It should be noted that the detection of ruthenium alone excludes the possibility of an accident on a nuclear power plant, which would result in the presence of other radionuclides. Ruthentium can occur in nuclear fuel cycle installation, in facilities manufacturing radioactive sources or in RTG's (Radioisotope thermoelectric generators) used for the power supply of satellites. Discussions with BfS, the German counterparts of IRSN, show that they reach similar conclusions.

At this stage, IRSN does not have information to confirm the end of the releases.

IRSN is continuing its efforts to monitor the level of ruthenium in the territory and its calculations to clarify the origin of the releases and their characteristics.

Notes:

1. Ruthenium 106 is a radionuclide of artificial origin. It is a fission product from the nuclear industry. This radionuclide is also used in the medical field for brachytherapy treatments.
2. In France, IRSN is responsible for monitoring the radioactivity of the atmosphere on a nation-wide scale. Its surveillance network OPERA-Air includes high-volume aerosol samplers (700 to 900 m³ of air per hour) and measurement equipment capable of detecting trace amounts of radioactivity.