WAR IN UKRAINE:IRSN MOBILIZED TO SERVEPUBLIC AUTHORITIESAND CITIZENS"Faced with an unexpected situation in emergency planification, IRSN has found innovative
responses that have enabled it to be effective, consistent, and to enhance its resilience. The strengthof the Institute lies in its ability to adapt to challenges and meet them by relying on a formidable
emergency response asset: the multidisciplinary nature of its teams. We possess knowledge of thenuclear facilities, environmental monitoring issues, radioactivity dispersion behavior, health risks,
the international situation, communication, and more. Through the synergy of all our skills, amplified
by this crisis, we are able to remain in a state of readiness for the duration with regard to the Ukraine
situation, covering a broad field, while preserving the Emergency Response Center’s responsivenessin its daily missions."
Jean-Christophe Niel,
Director General of IRSNOn February 24th, 2022, Russian troops invaded Ukraine on four fronts and seized control of the
Chornobyl site, where 20,000 spent fuel assemblies are stored. The very next day, IRSN mobilized
its emergency response organization, activating its Emergency Response Center (ERC) in Fontenayaux-Roses (Hauts-de-Seine) to carry out its technical and scientific missions to support national
public authorities and international bodies. These missions involve daily monitoring of radiationlevels on Ukrainian and European territories, assessing the safety of Ukrainian nuclear facilities;
anticipating possible accident situations and their potential consequences for populations andthe environment in Ukraine, Europe and France. IRSN was also mobilized to respond to media andcivil society inquiries and produced information notes and educational materials on the situationof nuclear facilities in Ukraine in order to contribute to an understanding of the risks.
But the war continued to drag on. At various times, Ukrainian nuclear facilities were hit by artillery
shellings, causing concerns as no other nuclear country had previously experienced an armed
conflict of this scale[1]. Never before had nuclear power plants been used as military targets, knowingthat they are not designed to withstand warfare. And the risk of a severe radiological accident had
never before posed such a serious threat to Europe.
Faced with this unprecedented, evolving and often disquieting situation, IRSN emergency response
teams, supported by various expert within the Institute, remain mobilized. For 10 months, they
adapted their organization, mobilization and involvement as the events, solicitations and issues
unfolded. Managing this crisis, different from that of Fukushima-Daiichi in Japan in 2011, led theInstitute to adjust the working methods of its Emergency Response Center. Internally, it involved
employees and fostered collaborative work and synergy among multidisciplinary teams. Externally,
it highlighted the importance of IRSN’s role as a technical expert able to provide support forthe public authorities in the ecosystem of international crisis management.

2

As of December 31, 2022, none of the attacks directed at Ukrainian nuclear facilities or power
infrastructure had caused damage to critical zones or generated any episodes of radioactive
release. No abnormal increase in radioactivity had been detected by the monitoring networks,
either in Ukraine or in neighboring countries. Nevertheless, major risks still persist. The Institutetherefore remains mobilized on active standby. IRSN will continue to support the nuclear safety
initiatives undertaken by European and international safety organizations, foremost among whichis the IAEA and its Director General Rafael Grossi, to preserve safety.

UKRAINE, A COUNTRY
WITH EXTENSIVE NUCLEAR FACILITIES
Ukraine is the world’s seventh-largest producer of nuclear power and, in an area slightly larger than France,
had a total of fifteen VVER pressurized water reactors of Russian design in operation over four production
sites on February 24, 2022. In addition to these nuclear power plants, there are:
Two research reactors;
Six storage and disposal sites for radioactive sources and waste;Four RBMK reactors at the Chornobyl site, shut down since 2000: three being dismantled, one under the sarcophagus (the damaged reactor);Various facilities required to manage the Chornobyl accident site, including a storage pool for 20,000 spent fuel assemblies and a dry storage
facility for 2,000 spent fuel assemblies.

ROBUST AND RESILIENT POWER PLANTS
Designed differently than Chornobyl, the reactors of the four Ukrainian
nuclear power plants meet international nuclear safety standards. Eachone was equipped from the outset with:
A pre-stressed concrete containment (except for two Rivne[2] reactors)
which also houses the spent fuel pool;Three independent standby emergency power generators with sevendays’ fuel autonomy. A single generator combined with a set of safetysystems is enough to cool the core of a reactor and the spent fuel pool.

In addition, Ukraine reinforced the safety of its power plants following
stress tests in Europe carried out after the Fukushima-Daiichi power plant
accident. Each power plant has mobile back-up equipment, enabling it todeal with the total failure of internal and external power supply (mobile
water injection heat pumps, mobile generators, with three days’ fuelautonomy).
The country has also launched the rollout of a filtered containment venting
system on its reactors, which limits, in the event of a severe accident, therelease of volatile radioactive elements. Other provisions, such as hydrogen
recombiners, have been installed to limit the risk of loss of containment.

[1] Slovenia’s war of independence had led, as a precaution, to the temporary shutdown of the Krško power plant in 1991.
[2] The Rivne power plant comprises two 440 MWe reactors, older than the other VVER reactors located in Ukraine.

3

A LONG TRADITION
OF COOPERATION BETWEEN
IRSN AND UKRAINEThe safety of Ukrainian nuclear power plants, all operated by the National
Nuclear Power Generation Company of Ukraine Energoatom, is controlled
by the SNRIU (State Nuclear Regulatory Inspectorate of Ukraine).
Following the Chornobyl accident, IRSN forged cooperative relationships
with SNRIU, within the framework of the European ICSN (Instrument
for Nuclear Safety Cooperation) program, through assistance and skills
transfer contracts in the field of nuclear safety and radiation protection.
These cooperative relationships – particularly in the context of postFukushima stress tests and as part of the European FASNET project, led
by IRSN, to prepare for and respond rapidly to nuclear emergencies at
the international level – have enabled the Institute to acquire knowledge
and data on east-European VVER reactors. Furthermore, the Institutebolstered its workforce with experts of Ukrainian nationality.
Since 2010, SSTC, the SNRIU technical safety organization (TSO), hasbeen an associate member of ETSON, the European TSO network,
which was created at the initiative of IRSN and Belgium and German TSO
to contribute to consolidating European nuclear safety.

10 MONTHS OF ATTACKSON UKRAINIAN
NUCLEAR FACILITIESPHASE 1 (FEBRUARY - MARCH)
DIVERSE ATTACKSF ebruary 25, 2022: Intrusion into the Chornobyl exclusionzone. Takeover of the site, occupied for 35 days. The media
report on increased levels of radioactivity in the exclusionzone.
N ight of February 26 to 27: Attack on a waste disposalsite in Kyiv, no radioactive release.
N ight of March 3 to 4: Attack and takeover ofthe Zaporizhzhya power plant, the largest in Europe.
M arch 6 and 11: Shelling of the Kharkiv Institute of Physics
Research Center.
M arch 9: Loss of external power supply to all Chornobyl
power plant facilities.
M arch 11–21: Forest fires in parts of the Chornobyl exclusionzone generate an increase in measured radiation levels.

PHASE 2 (APRIL - JULY)IN BRIEF

THE CONFLICT IN DEADLOCK
April 26: Arrival of IAEA mission at the Chornobyl site
after the withdrawal of Russian troops.

REACTOR SAFETY
IN AN ACCIDENT SITUATION
Three conditions are essential to maintaining
the safety of an operated or shut-down reactor:
Water supply for the cooling circuits;Power supply to operate safety equipment and to run
the water injection pumps in the reactor core or spent
fuel pool and the cooling circuit pumps;
Trained operating and maintenance personnel, who areoperational and free to make their own decisions andact on them.

PHASE 3 (AUGUST - MID-OCTOBER)REPEATED OFFENSIVES NEAR AND
AGAINST NUCLEAR POWER PLANTS
A ugust to November: More than twelve successive attacks(shelling) on the Zaporizhzhya site, generating major concerns
about the possible consequences.
E nd of August: Arrival of a permanent delegation of IAEA
inspectors in Zaporizhzhya.
S eptember 11: Total shutdown of the last reactor stillin operation at the Zaporizhzhya power plant.

PHASE 4 (MID-OCTOBER - DECEMBER)
A STRATEGY OF SHELLING ENERGY,
ELECTRICITY AND WATER PRODUCTION
AND DISTRIBUTION INFRASTRUCTURE
N ovember 15: Loss of one external power line at the
Rivne plant. Shutdown of a reactor. Power reduction in
the other three reactors. Shutdown of the two reactors
at the Khmelnitskyi power plant.
N ovember 23: Loss of the national power grid. Automatic
shutdown of all units at the nuclear power plants on the
Rivne, Khmelnitskyi, South Ukraine and Zaporizhzhya sites.

4

IRSN’S INVOLVEMENT
IN MANAGING THE UKRAINE CRISISPROVIDING SCIENTIFIC ADVICE AND OPERATIONALASSISTANCE TO PUBLIC AUTHORITIES
answering questions and direct requests from several ministries:
Health, Europe and Foreign Affairs, Armed Forces, Labor, Ecological Transition, etc.

MOBILIZING
02.25 TO 04.08: SETTING-UP THE EMERGENCYRESPONSE CENTER (ERC), DAILY MEETINGS
Director General, Crisis Director, Head of Emergency Assessment,“Facilities Evaluation” unit, “Radiological Consequences” unit, “Health”
unit, “International” unit, “Communication” unit, “Logistical Support”
unit + Ukraine pool and Operating Office of the Emergency Response
CenterINVOLVING IN-HOUSE EXPERTISE ON A LARGE SCALE
Request for nine IRSN expert assessment services

ASSESSING THE POTENTIAL RADIOLOGICALRISKS AND CONSEQUENCES
BUILDING A FORMAL AND INFORMAL NETWORKOF INTERNATIONAL CONTACTS to escalate and aggregate reliable
assessment data (Ukrainian employees, IAEA/USIE, SNRIU, Energoatom,
SSTC (Ukrainian TSO), embassies, IAEA/IEC, NNSA, NARAC)

PRODUCTION OF “ATYPICAL” ASSESSMENTS
FOR A BETTER ANTICIPATION afety assessment of Ukrainian power plants
S
Catalog of standard accident sheets for each family of Ukrainian
nuclear facilities
Worse-case scenario of radiological releases and consequences
Risk studies

ADAPTING TO A LONG-TERM CRISIS
08.22 TO 12.31: ACTIVE STANDBYANTICIPATING A POST-ACCIDENT SITUATION eekly meetings and monitoring bulletinsWSafety monitoringEnvironmental monitoring (daily monitoring)International monitoring
Social network and media monitoring

Assessment of the consequences of a serious accident
in Ukraine (possible restrictions on food marketingand consumption)

CONTINUOUSLY INFORMING IN
AN OPEN AND INSTRUCTIVE MANNER
PUBLICATION AND DISSEMINATION OF THE RESULTS
OF EXPERT ASSESSMENTS IN THE FORM OF TECHNICALBRIEFING NOTES, PRESS RELEASES, EDUCATIONAL
MATERIALS TAILORED FOR THE GENERAL PUBLIC,
INTERNAL BRIEFING NOTES: hree briefing notes on the “Situation of nuclear facilities in Ukraine”
TOne educational notice: “Taking stable iodine tablets in emergency
situations”
Two briefing notes on the “Situation at the Chornobyl site”
Four briefing notes on the “Situation at the Zaporizhzhya power plant”
One briefing note entitled “Impact of the deterioration of the Ukrainian
national power grid on nuclear power plants”
Internal webinars
Internal videos
Media: www.irsn.fr, social networks, REPERES external magazine,
the IRSN newsletter, MyIRSN intranet, in-house magazine

RESPONSE TO A HIGH INFLUX OF REQUESTS:
Media
NGOs (Doctors Without Borders, etc.)
Associations (CLI, ANCCLI, CRIIRAD, Greenpeace)Companies (France TV)
HCTISN (High committee for transparency of information
on nuclear safety)
General public
IRSN employees
Parliamentarians, Elected Officials

5

ANTICIPATINGThe European theater of the crisis in Ukraine and the kinetics of events have challenged
IRSN with unprecedented situations. To increase its responsiveness and enable
the Government to anticipate the protective measures to be taken in France in the eventof a severe radiological accident in Ukraine, the Institute has taken the initiative to broaden
the scope of the assessments it usually carries out in emergency situations. It has worked
in real-time on scenarios to anticipate serious events across Ukraine, adapting its tools
and methods, and mobilizing targeted competences.

A STANDARD EMERGENCY RESPONSE
ORGANIZATION TO START WITH

A WIDE RANGE OF FRONTS,
UNPRECEDENTED ISSUES

As soon as the Emergency Response Center (ERC) was activated, at midday
on February 25, the IRSN emergency response organization’s technicalunits were set up and running at the crisis director’s request. Media
demand for information intensified. The supervisory authorities requested
an analysis of the situation in Ukraine and advice on protective actions to
be considered. The Institutes teams were immediately set to work in thevarious units, including “Facilities Evaluation”, “Radiological Consequences”,“Health”, “Communication”, “International” and “Logistical Support”. Within
the first few hours, they conducted an analysis of the events, making it
possible to produce and disseminate a preliminary briefing note on
the “Situation of nuclear facilities in Ukraine”.

From the end of February to mid-March, the “Ukraine pool” was called
upon to focus its assessments on highly mobile fronts: the Chornobylsite located less than 150 km from Kyiv, the capital of Ukraine, to thenorth; Zaporizhzhya, Europe’s largest power plant, to the south-east;a waste disposal site near Kyiv; an experimental reactor in Kharkiv, tothe north-east; then Chornobyl once again... The crisis team must adapt
to the diverse types of nuclear facilities across the vast territory of
Ukraine and the many radiological issues associated with them.

During the first six weeks of the conflict, marked by a constantly changing
and particularly unsettling situation, the ERC remained mobilized, mostfrequently during working hours. Gradually, a “Ukraine pool” of aroundthirty team members was formed to manage the crisis on an ongoingbasis. It receives assistance when needed from specialized support units.
Every morning, and as required, the crisis manager organizes a situational
briefing, and decides what assessment work needs to be launched,
and which methods and resources mobilized. He serves as the contact
person for the public authorities.

Rapidly, specific problems emerged which the teams had not encountered
while managing the previous international nuclear crisis, that of the
Fukushima-Daiichi power plant in 2011: .
H
 ow can objective event information be collected when the military
conflict in Ukraine is accompanied by an “information warfare” that
requires the deciphering of not only technical but also political andstrategic situations?
H ow can reliable technical information be reported and centralized
to guarantee the quality of IRSN’s assessments on the radiologicalconsequences of attacks on Ukrainian power plants? IRSN is not in
direct contact with Ukrainian operators, as they are with EDF in France;
in Chornobyl and Zaporizhzhya, Ukrainian operatives work under
the constraints of the Russian army.
H ow is it possible to characterize spent fuel storage sites and research
reactors on which IRSN has no data? It is difficult to accurately calculatepotential radioactive releases when parameters are missing.

30

TEAM
MEMBERS
FORM THE“UKRAINE POOL”

IRSN has more knowledge at its disposal concerning the four Ukrainian
VVER power plants because their technology is close to that of French
power plants; the results of their European post-Fukushima stress tests
provide useful information. Nevertheless, many questions remain:
have maintenance operations been carried out? What is the status of
the safety provisions? What is the condition of the emergency power
generators, and what is their reliability over time? How badly haveworking conditions deteriorated for the Ukrainian personnel working
under constraint?
This anticipatory questioning is bound to continue throughout the crisis.
Over the course of events, new topics of investigation have emerged,
such as the ability of the power stations and their backup systems to getthrough the winter, or the risks linked to the destruction of the Dnieper
dams upstream and downstream of the facilities.

6LOSS OF ELECTRICAL SOURCES:A SENSITIVE SUBJECT QUICKLY SPOTLIGHTED"As early as February 25, we diagnosed a critical threat in
our safety analysis: the shelling of the Ukrainian electric
grid could lead to the loss of power to nuclear facility safetysystems. Very quickly, IRSN decided to develop expertiseon this complex topic. For months, we collected andconsolidated information on the Ukrainian power generationand distribution grid and retrieved or established power
plant connection diagrams. To do this, we mobilized power
distribution specialists and had discussions with SNRIU
and the IAEA, who had dispatched a mission on site. This
work helped us better assess the situation and risks for each
episode of power line loss. We even anticipated a widespread
grid incident that would lead to the automatic shutdown of allplants. This is an issue that has remained a constant concern
throughout the crisis. However, it should be emphasized that,over the course of the year, the Ukrainian energy companies
have always been able to repair damage to the power grid
to maintain the safety of the facilities."
Emmanuel Raimond,
Leader of the “Facilities Evaluation”
unit, Head of the Reactor
Emergency Operating Department
and Probabilistic Safety Studies

360° SUPPORT FOR THE PUBLIC AUTHORITIES"This unprecedented context of an international crisis has
confirmed IRSN’s pivotal role in supporting national publicauthorities and international bodies. This war, which erupted
at the very threshold of Europe and posed serious radiologicalthreats on the continent, has led those responsible forhandling crises at the highest levels of Government to lookbeyond the national frame of reference. The French Ministriesof Ecological Transition, Health, Foreign Affairs, the Armed
Forces, and Labor, and the State operators approached
us directly, as a public expert on nuclear and radiologicalrisks, for expert assessments and operational support withincreasingly extended scope.
Internationally, we have had technical discussions with the
IAEA, which has played a central role in disseminating theinformation it has centralized to the UN Member States aswell as in managing this crisis, highlighting repeatedly thechallenges this represents for nuclear safety. We have also had
direct contact with SNRIU and shared assessment intelligencewith our counterparts in the USA, Canada, Norway, Finland,and Germany.
Lastly, the Ukraine crisis has given rise to a network of crisis
actors within ministries and international bodies. It has
federated a new national community which has further
extended internationally. As is often the case, an emergency
situation has been an accelerator of organizational
development."
Louis-Michel Guillaume,
Deputy Director Generalof the Defense, Security
and Non-Proliferation Division

7

PRODUCING ATYPICALANTICIPATION ASSESSMENTS
IN EMERGENCY SITUATIONS
As attacks on Ukrainian nuclear facilities continued, so did the questions
raise in the media and referrals issued by the State. In response, IRSN
experts have produced numerous calculations of possible consequences
for populations and the environment. These assessments have been partof a process of preparing for and anticipating a radiological event. They
have resulted in the drafting of technical briefing notes distributed tothe public authorities and the media, before being laid out for public.
In the space of a few days, with the support of other IRSN departments,
the “Ukraine pool” produced the following:A catalog of Standard Accident Sheets for each family of Ukrainian
nuclear facilities: the 1,000 MWe and 440 MWe VVER operated reactors,
research reactors, waste disposal sites, and spent fuel pools. The “Facilities
Evaluation” unit identified the scenarios that could occur at the different
facilities and the atmospheric releases into the environment associatedwith these scenarios. Then, the “Radiological Consequences” unit assessed
the consequences for populations and the environment under different
meteorological conditions. These sheets provide an order of magnitude
for each typology of accidental release.
Assessments for obtaining an order of magnitude of iodine releases
for different accident scenarios at the Ukrainian power plants and for
determining whether dose levels justifying the administration of stableiodine could be exceeded on French territory. This work has provided
operational responses for the public authorities.
In November, IRSN extended its studies on the start of the post-accident
component in order to assess any actions to limit the consumption
and marketing of certain foodstuffs that may prove necessary to comply
with regulations in force and taking into account the impact ofcontamination on territories across Europe.

EVERYONE MOBILIZED, EVERYONE INVOLVED
IN A CROSS-FUNCTIONAL CHALLENGE"To produce our studies on Ukraine, we called on experts
from two specialized services from IRSN’s nuclear safety
division: from Fontenay-aux-Roses and Cadarache where
they were based, experts from the Neutron Physics
Department for Criticality Risks (SNC) and from the Major
Accidents Department (SAM) took up the subject. Using
more sophisticated calculation resources than those of
the ERC – which relies on simplified tools to enhance its
reactivity – they have developed data sets representative of
Ukrainian power plants, enabling us to perform radioactive
release calculations using complex models that will be
extremely useful in the event of actual releases in Ukraine.
Throughout the crisis, the ERC has relied on internal
expertise from many departments: for assessment of safety
against malicious acts, nuclear safety studies, the safety oftransport and fuel cycle facilities, the power grid, the safetyof nuclear research facilities, atmospheric dispersion andthe radiological consequences, severe accidents, healthcare
and the environment, VVER experts, the IT department,purchasing, etc. This peripheral network has brought a great
deal of added value, shedding light on certain subjects,
and allowing progress to be made on others. The ERC has
helped the Institute to innovate and develop new skills. It
has stimulated collaborative work and team spirit. Mobilizing
skills outside the “hard core” of the ERC crisis organization
is an example of our target mode of organization. This
unprecedented experience strengthens our conviction thatcrisis management is a cross-functional subject. Not only
does it mobilize many multidisciplinary skills, it also involves
a broad spectrum of the Institute’s employees, who take aninterest in what their company produces in this crisis so thatthey too can provide objective insight into stressful events."
Philippe Dubiau,
Executive Director for Emergency
Preparedness and Response

8

MONITORING
Monitoring is at the heart of IRSN’s emergency response expertise. It is based on a 24/7
operational warning system that guarantees the rapid acquisition of data in order to assess
the risks as quickly as possible and protect the health of populations. To remain effective
and reactive to numerous and diverse events occurring outside French borders, in a context
where it has been difficult to recover reliable information, IRSN has extended its reach beyond
its standard frame of reference. The Institute has adapted its monitoring organization andbroadened the usual scope of its monitoring systems by deploying them in four areas: media,
international, safety, and Europe-wide environmental monitoring.

ORGANIZED MONITORING SYSTEMS
Faced, on the one hand, with a lack of readily available technical data on thedesign of nuclear facilities in Ukraine and, on the other, with the difficultyof accessing reliable event-based information on the shelling that haveoccurred, the need to implement four monitoring systems became quickly
apparent. During the six weeks of ERC activation, these organized watches
produce daily – sometimes twice or three-times daily – situation reports,
making it possible to review and decide on actions at the morning crisis
meeting. They also feed into the regular flow of information that IRSN
passes on to the public authorities.
This monitoring, which was scaled down on April 8, resumed at amore sustained pace on 22 August, when repeated strikes against theZaporizhzhya power plant led IRSN to reactivate its crisis organization in
the form of “active standby”, punctuated by meetings and situation reports,
which were no longer daily but weekly.

MEDIA WATCH
In order to be able to detect weak signals and to inform the ERC’s technicalteams in real time of events taking place in Ukraine, the “Communication”
unit activated a media watch in France and abroad starting fromFebruary 25. Building on the Communication Department’s tools, thiswatch is based on:
Monitoring of all social networks, via hashtag-keywords (themes, nuclear
sites that could be attacked, etc.) programmed on search engines. This
monitoring includes Telegram – an alternative to WhatsApp –, which ishugely popular in Ukraine and has been used by the Ukrainian authorities
to disseminate information since they were deprived of other means ofcommunication.
A watch of all conventional media (agencies, radios, TV, print media)
to produce a daily IRSN “Ukraine special” press overview summarizing
around 100 press clippings.

CROSS-REFERENCING AND VERIFICATION:
A CONSTANT CONCERN"The information war waged between Ukraine and Russia
since day one is an extremely complex component of thiswar. It puts our ability to analyze, cross-check and verify
information to the test. Beside the facts, and sometimes
even before the facts, there are comments, influencing
and fake news across the social networks. It is very
difficult to distinguish information from disinformation.
The communicators spend a lot of time sorting throughand analyzing the content and information in orderto qualify them before passing them on to the technicalexperts of the ERC to contribute to the analyses."
Marie Riet-Hucheloup,
Communication Director

INTERNATIONAL WATCH
At the same time, international monitoring has been set up. The“International” unit teams collect the information published by IRSN’s
historical international partners, from their respective websites: the crisis
centers for technical support (TSO) and safety authorities in European
countries as well as international organizations such as NNSA (National
Nuclear Security Administration) and NARAC (National AtmosphericRelease Advisory Center). They also cull the key elements of diplomaticnews in relation to Ukraine and Russia. The teams publish a monitoringbulletin covering recurring themes that provide insight into the positionof the various States and international agencies: how these are reacting,what preparations they are making, how they organize themselves,
why they have decided to break off relations with Russia, etc.

9

SAFETY WATCH
As for the “Facilities Evaluation” unit experts, they have been collecting
information on safety, first at the Chornobyl site, then at the Zaporizhzhya
power plant, then at all the other facilities located across Ukraine. The
challenge is to rapidly calculate the orders of magnitude of potential
radioactive releases and the radiological consequences of possible accident
situations. Knowledge about each reactor must be consolidated in order toanticipate accidental scenarios and provide an opinion on the seriousnessof a situation very promptly, when one occurs.
With the support of Ukrainian colleagues who speak the language and arefamiliar with facility designs, the teams enter into direct contact with SNRIU
and other local actors. The teams seek first-hand information to ensure thatthey correctly interpret the information provided by Energoatom about
the situation. They also discuss situations and release calculations with
their contacts from foreign safety organizations: GRS and BfS in Germany,
STUK in Finland, SSM in Sweden, DOE in the USA. They have technicaldiscussions with the IAEA Incident and Emergency Center (IEC).

THE ENVIRONMENTAL MONITORING SYSTEM IN UKRAINEAND NEIGHBORING COUNTRIES: A KEY TO IRSN’S VALUECREATION DURING THE CRISIS
The monitoring system implemented by IRSN crossmatches andaggregates data from 1,100 sensors belonging to different monitoring
networks:
In Ukraine:Data from the Teleray radiation station of the French Embassy in Kyiv
and the IRSN station installed in Lviv when the Embassy was relocated;Data from the Ukrainian national network via the European EURDEP
platform;
Data from Ukrainian nuclear operators and the Ecocentre (Ukrainian
Public Agency for the Management of the Chornobyl Exclusion Zone)
via the IAEA web-based tool, IRMIS;Data from accessible web-based aggregation sites such as SaveEcoBot(aggregation of data from the Ecocentre, Ukrainian nuclear operators,
and the Ukrainian HydroMet network).
In neighboring European countries:
Data from national monitoring networks via the European EURDEP
platform.
This system automatically provides real-time, clear visualization of thedose rate evolution over a wide area.
In France, permanent nationwide radiological monitoring is carriedout by:The Teleray network operated by IRSN (440 radiation monitoring
stations in metropolitan France and overseas territories that transmit
an ambient dose rate measurement every 10 minutes);
The IRSN OPERA-Air network (50 air sampling stations in metropolitan
France);O perator monitoring networks (EDF, CEA, ORANO La Hague):
550 radiation monitoring stations.

10

ENVIRONMENTAL MONITORINGEXPANDED TO EUROPE"The taking of the Chornobyl site and the rise, measured on
certain radiation monitors and reported by press agencies, inthe level of radioactivity at the time of the Russian offensive,raised the question of environmental monitoring in Ukraine
from day 1 of the war. How can you get to grips with theradiological situation in a distant country in order to put inplace an expert assessment? On February 24, IRSN could
rely only on one single, and vulnerable, tool which was
exposed to the shelling: the equivalent dose rate radiation
stations deployed by the monitoring networks of various
countries, such as the French Teleray network radiation
monitor installed on the French Embassy in Kyiv.
The solution was to organize remote monitoring. Very quickly,
we put in place a system allowing us to analyze the radiologicalsituation in Ukraine on a daily basis and inform the publicauthorities. This system collects radiation stations data from thevarious Ukrainian monitoring networks, in particular the data
automatically transmitted to the European EURDEP network,and that of the IRMIS platform of the IAEA. Our monitoring has
been expanded to include all neighboring countries of Ukraine,with a dual objective of backup and warning: detecting aradiological event that Ukrainian radiation monitors, inoperative
due to shelling or power outages, for example, would beunable to detect; and being able, if necessary, to inform the
French Ministry of Foreign Affairs about protection measures
for French nationals present in Eastern Europe. This monitoring
provides a snapshot of the radiological situation in Ukraine.
We also talk about the data with our counterparts, who passon the intelligence to their own national authorities.
Second, with the help of IRSN’s environmental data specialists,
we have optimized the efficiency of this monitoring, which
aggregates a huge amount of information, with some radiation
stations transmitting a measurement every 10 minutes. This
included setting up a dedicated database and easy-to-use
interoperable interfaces for crisis teams and radiologicalremote monitoring teams who are on call around the clock.
This automated system enables us to perform a rapid andprecise analysis and interpretation of any abnormal increasein radioactivity levels, which are not necessarily linked to an
incident at a nuclear facility. Such a spike may be due to natural
events (storms, rain, drought), or a failure of the radiation
stations."
Maxime Morin,
Leader of radiological monitoringin Ukraine, in neighboring countries
and in France, and Head of theEnvironmental Metrology Analysis
Department

IN TIMES OF WAR, TRUTH IS GAUGEDBY ENVIRONMENTAL MONITORINGSTATIONS RESULTS"In a country at war, where the battle of communication
requires a highly critical approach to understanding theinformation disseminated by the belligerents about the natureof the damage, the only way to know whether a nuclear
facility has released radioactivity into the environment is to takemeasurements around the facility under attack. The monitoringof radioactivity in Ukraine has made it possible to objectively
gauge the safety assessments of the “Facilities Evaluation” unit,
which had very little information to work with at the start ofthe conflict. This monitoring indicated whether the firing andshelling might have hit a safety-critical area. Thanks to theprofessionalism and training of the environmental monitoring
teams, IRSN is able to accurately interpret any variation inradioactivity levels and indicate whether this can be explainedby weather conditions, the failure of a radiation monitoring
station, or some other cause."
Éric Cogez,
Head of Crisis Expertise,
Head of the RadiologicalIntervention and Environmental
Monitoring Department

MONITORING WITH AN
OPERATIONAL EMPHASIS
These four “watch units” set up by IRSN are not only used to provide a daily
or weekly snapshot of developments in the situation. They also constitutefour action levers:
They help the Crisis Director decide on work to be launched or initiatives
to be taken to solve problems or anticipate solutions to emerging issues.
They provide the “Facilities Evaluation” and “Radiological Consequences”
units with a sum of verified knowledge and data, to consolidate andreinforce the reliability of the assessments they carry out.

A SUCCESSION OF SAFETY
AND RADIATION PROTECTIONASSESSMENTS IN DIFFERENT LOCATIONS
After each event on a nuclear site, IRSN’s diagnostics shed light on thesituation. These diagnostics provide objective scientific insight into thenature of the actual damage and associated risks in a context where
information is difficult to obtain and validate. The expert assessments
provide input for technical briefing notes written up for the publicauthorities and, when appropriate, for elected representatives andassociations, and published on the IRSN website.

EventsIRSN expert assessments

Increase in the radioactivity levelmeasured by certain radiation stationsin the Chornobyl exclusion zone

After exchanges with its European partners and the IAEA, the “Radiological Consequences”
unit tends to favor the explanation of a technical malfunction of the radiation stations, without
excluding the hypothesis of Russian tanks disturbing radioactive dust by driving through the area.

Power supply cut off for all Chornobyl
power plant facilities. Evoking the riskof a “new Chornobyl”

The “Facilities Evaluation” unit dismissed a dewatering risk of the assemblies in the spent fuelpool, based on post-Fukushima studies and its own calculations. It assesses the site’s otherissues: risks associated with direct shelling of the sarcophagus and of the spent fuel pools.

The first shelling of the Zaporizhzhya
power station indicating damage
to the containment

The “Radiological Consequences” unit confirmed the absence of releases. The “Facilities
Evaluation” unit, based on a study of the power plant design and its power supply resources,
assessed the robustness of the power plant and confirmed approximately 10 days of autonomy
in the event of total loss of external power supply, provided that the site teams remain
operational.

Forest fires in the Chornobyl exclusionzone leading to an increase inmeasured radioactivity

The “Radiological Consequences” unit combined the data from its monitoring in Ukraine withthe measurements of aerosol filters from other European countries and its OPERA-Air network,
which detects minute traces of radioactivity in the air. No abnormal increase in radioactivity
was observed.

Month-long shelling at theZaporizhzhya power plant,
which give cause for concern

The “Facilities Evaluation” unit approached the Energoatom operator to assess the extensive
damage. The “Radiological Consequences” unit measured no increase in radioactivity.
IRSN alerted the authorities to the degraded situation of the power plant and detailed the site’svulnerabilities: areas identified as safety-critical with regard to radiological risks and the main
safety issues.

Loss of power supply to the SouthUkraine power plant, then systematic
shelling of the Ukrainian power gridleading to the automatic shutdownof all reactors at the four power plants

The “Facilities Evaluation” unit assessed the means and time required to gradually rebuild
the power grid in order to restart the reactors. IRSN stressed the need to reconstruct thenational power grid to guarantee a sustainable power supply for nuclear site safety systems.

Arrival of winterThe “Facilities Evaluation” unit carried out a preventive assessment of the capacity of Ukrainian
power plants (in particular Zaporizhzhya) to manage the winter season. The unit validated withthe operator the implementation of thermal protection for the emergency power generators.

10

TECHNICALBRIEFING NOTESFOR THE PUBLIC
AUTHORITIES hree briefing notes on
T“The situation of nuclear
facilities in Ukraine”
Two briefing notes
on “The situation at
the Chornobyl site”
Four briefing notes
on “The situation at
the Zaporizhzhya
power plant”
One briefing noteon “The impact ofdeterioration of the
Ukrainian national power
grid on the nuclear
power plants”+1

EDUCATIONAL NOTICEON “THE TAKING OF STABLE
IODINE TABLETS IN AN
EMERGENCY SITUATION”

11

ADAPTING
IRSN demonstrated agility throughout the 10 months of war in 2022. It has undergone
a transformation, by reaching beyond its traditional emergency response “procedures”,
poorly suited to the situation in Ukraine. Innovation has enabled it to adapt its organization,
mobilization, involvement, methods, and tools to address the specific features of the
Ukraine crisis: highly fluctuating events and demands, intense periods, no accidents
but a permanent risk, continuous tension, and a long crisis with no end in sight.

FLEXIBLE EMERGENCY RESPONSE
CENTER ORGANIZATIONTHE ACTIVATION OF AN INNOVATIVE“ACTIVE STANDBY” ORGANIZATION

During the ERC’s set-up period, the crisis organization went beyond its
traditional frame of reference, while remaining true to its main principles.
To adapt to highly fluctuating events and demands, the crisis units andmobilized workforce vary from day to day, and often over the course of thesame day, depending on what has to be dealt with. They work in hybrid
mode: some on site, others remotely.

On April 8, 2022, IRSN scaled back its watch system, while remaining
available for its contacts. There were several reasons for this choice: theconflict was becoming entrenched and the tension around the Ukrainian
nuclear sites, including Zaporizhzhya, was decreasing. The teams that had
been highly involved over these weeks were also mobilized on national
or international topics. IRSN’s approach had to be a long-term one.

The work is carried out mainly during working hours by the “Ukraine pool”
team representing the key functions. These experts, mobilized from thestart of the crisis, have access to the history of all the actions carried out
by the ERC. At night and on weekends, the on-call team members ensure
monitoring activities, ready to alert the Emergency Response Director,
carry out initial assessments, and, in the case of a major event, call on
the “Ukraine pool” team members to assist.

In August, the Zaporizhzhya power plant was subject to particularly
worrying repeated shelling. On August 22, IRSN decided to remobilize theteam members of the “Ukraine pool”. It chose an innovative “active standby”
format that was not envisaged in its organization. The objective was tomobilize the teams by setting up regular consultation meetings basedon the situation briefings established by the four reactivated monitoringmechanisms (media, safety, environmental monitoring, international). Since
then, every Monday, the Crisis Director has invited the facilitators of the“Ukraine pool” units as well as the main on-call team members who may
be called upon “on the spot”, to give an overview of the week’s current
events, to give briefings on the work in progress, to define the directions totake, the work to be initiated, and the documents to be produced in order
to inform the public authorities and to keep the media and civil society inthe loop. This simplified system has enabled IRSN to demonstrate a highlevel of reactivity when faced with six real events successively in less than
30 days in France, from September to mid-October, and to implement its
program of crisis exercises and visits (see chapter: Crisis and Post-Accidentof the 2022 Annuel Report).

REGULAR OPERATIONAL TRAININGFOR ON-CALL TEAM MEMBERS
In order to build on-call team members’ awareness of the real risks to
Ukrainian nuclear facilities, training sessions are regularly organized. These
operational exercises are based on the theoretical anticipation carried out
by their colleagues in the “Ukraine pool”: the Standard Accident Sheets foreach family of Ukrainian nuclear facilities and the pre-calculated worsecase scenario. Based on the values of an accident scenario and the day’s
meteorological data from Météo France, the on-call team members practice
making calculations across the entire operational chain: assessment of theaccident situation, calculation of the release, estimation of the spread of theplume over Europe, identification of zones that would require protection
measures for the populations, drafting of the ERC external message of
information for the public authorities. These training sessions, implemented
before summer 2022, were reactivated in mid-November on a weekly
basis. They promote knowledge sharing and relaying of information
between the “Ukraine pool” team members, who are at the front line ofcrisis management, and the on-call team members pool, further awayfrom the heat of the action. These sessions reinforce the engagementof the Institute’s employees and help to ensure the reactivity of all crisis
pool teams in case of a serious event in Ukraine.

12THE UNPRECEDENTED SET-UP
OF AN “INTERNATIONAL” UNIT
An “International” unit created after the Fukushima-Daiichi power plant
accident, rarely called upon in the context of national exercises, setthemselves up at the ERC on February 25 to help collect and cross-checkinformation for an objective insight into events. This unit is responsiblefor international ties with two types of contacts: the network of IRSN’s
historical technical partners and the network of institutional contacts.
It first organized and produced a daily international monitoring report, thena weekly one. After each attack on a nuclear facility, it closely monitored
the situational self-appraisal information posted by SNRIU on two platforms
administered by the IAEA: USIE, the unified system for the exchange of
information in the event of an incident or emergency, and IRMIS, theinternational radiological control information system. It reported on
the press conferences of IAEA Director General Rafael Grossi.

THE UKRAINE CRISIS HAS STRENGTHENEDTHE NEED FOR EXCHANGES WITH OURTECHNICAL COUNTERPARTS AND OUR
INSTITUTIONAL CONTACTS ABROAD"For many years, and especially since the Fukushima-Daiichi
accident, IRSN has been working with its counterparts in
Europe and around the world to build common emergency
response expertise, involving common risk assessment,
technical assessment methods, and shared tools forassessments and release prognostics, etc. With a strong
international presence in crisis management, the Institutehas established partnerships with major emergency centersof technical bodies and safety authorities. It is therefore
quite natural that, from the start of the events in Ukraine,
we have established regular exchanges with our historicalpartners: GRS and BfS in Germany, US-DOE NNSA, as wellas the US-NRC in the USA, STUK in Finland, SSM in Sweden
and BelV in Belgium. The challenge was to understandeveryone’s levels of mobilization and preparedness, and toall be able to build a common assessment framework inorder to support decisions of the public authorities in Europe
should an event occur. These contacts led us to sharetechnical products that we had not previously exchanged,
and to check that everyone could use the technical data
into their workflow.
We established the same type of exchanges with the IEC, the
IAEA emergency center, although our relations had not yet
been formalized. The IAEA had specific technical questions
about the risks associated with the Ukraine situation.
The Institute provided it with safety analysis data.
Also in the context of the Ukraine crisis, we have had
discussions with WENRA, the association of safety
authorities in Western European countries, chaired in 2022
by the ASN. We participated in meetings with the European
Commission, giving rise to an inter-comparison report ofexpert capacities on a European scale to achieve enhanced
integration."
Olivier Isnard,
Deputy Executive Director,
interfacing with the international
information networks

13

INFORMING
As part of a process of transparency and openness to society, IRSN has been heavily involved
in responding to media requests and the specific queries of other stakeholders in civil society.
The Institute has published educational, technical, and scientific briefing notes and news briefs.
New in-house communication initiatives enable employees to stay informed of the situationand of the actions taken by the Institute.

A COMMUNICATION TEAMIN A STATE OF ALERTFrom the start of the conflict, IRSN’s communication department wason alert. The teams set up a media watch on the threats of a war. Media
pressure was stepped up on February 24. To respond to these initial
requests, IRSN decided to activate the crisis organization in standby
mode before officially setting up the ERC on February 25. Immediately,
the “Communication” unit put in place the “Ukraine special” media
watch mechanism, integrating all social networks and conventional
media in France and abroad. To keep the ERC teams updated on events,
it produced one or more daily summaries, depending on the current
situation. Highlighting areas of concern among elected representatives,
associations, the workforce and citizens, this media watch guided IRSN’s
decision-making on technical assessments to be launched or thematic
language elements to be developed.

OPEN AND EDUCATIONAL
INFORMATION IN RESPONSE
TO MEDIA PRESSURE
Over the next few days, journalists’ questions came in thick and fast. Twospokespersons were chosen: one to answer questions relating to safety,
and the other to address radiation protection/health issues. Their number
was deliberately kept to a minimum due to the volatility of the events,
which required in-depth knowledge of a subject in constant evolution.
The Communication team managed the technical information producedby the ERC to answer as clearly and simply as possible the questions that
kept recurring: What nuclear facilities exist in Ukraine? What is the conditionof these power plants (technology, robustness, safety status, etc.)? Whatis the radiological situation? Is there a risk? If so, what kind of risk?
Once the ERC produced a briefing note, the Communication Department
disseminated it and promoted it internally and, where appropriate,in the media and on the Institute’s website (irsn.fr).
The press office investigated all media requests and, in conjunction
with IRSN experts, followed up on them.
Once established, this process continued: producing, transmitting,publishing, informing, and answering media questions.

14Media pressure peaked on several occasions. The experts were particularly
solicited for the events of February 24, March 4 and March 9, in an
unprecedented context of information warfare, then again in August andearly September when the IAEA mission to Zaporizhzhya submitted
its inspection report.

PROCESSING MANY OTHER REQUESTS
The communication department also received requests from other actors,
sent directly or via other IRSN departments. These requests came from the
HCTISN (High Committee for Transparency and Information on Nuclear
Safety), from associations (CLIs, ANCCLI, CRIIRAD, Greenpeace, etc.),from NGOs, and even from companies that want to know what radiation
protection measures and equipment are needed for their employees.
Here are a few examples:M édecins Sans Frontières/Doctors Without Borders (MSF) requested
training support for its teams departing for Ukraine.
F rance Télévision asked for recommendations on the equipment of
its journalists and filming teams who were shooting the evening
news in the city of Lviv, in Ukraine.
CRIIRAD asked questions about IRSN’s assessments.
Each time, the ERC studied the request, defined the Institute’s position,and determined which expert contact to assign for the response.

300

PRESS REQUESTS
THAT LED TO
INTERVIEWS IN THE
WRITTEN PRESS,
ON THE WEB,RADIO ANDTELEVISIONREINFORCED INTERNALCOMMUNICATION TO LEVERAGE
COLLECTIVE STRENGTH
As soon as the ERC was activated, an internal message informed all
employees of the situation. It announced the setting up of the crisis
organization, explained that the Institute had been called upon andmobilized for the war in Ukraine, and that it had moved into operation
to produce expert assessments and provide support to the publicauthorities within the framework of its missions.
The internal communication teams reported statements, as well as
the media coverage. This regular flow of information allowed employees
to be given insight into the events.
Nevertheless, the war continued to rage. IRSN needed to strengthen
its internal communication. If a serious event occurred in Ukraine, allemployees would serve as spokespeople for the Institute with regard
to their family, circle of acquaintances, and the outside world.
In addition, the management of this long-term crisis required more andmore employees – not always members of the crisis pool – to carry out
expert assessments. IRSN wanted to promote this new cross-functionaland collaborative dynamic. To do so, the Institute launched two new
initiatives in September:T wo internal webinars. These Teams conferences were attended byalmost 500 employees. The presenters explained the nature, depth,and scope of IRSN’s work as part of its missions, with a focus on safetyassessments of Ukrainian facilities, the problem of losing power supply,
the environmental monitoring system in place, exchanges and modesof cooperation with SNRIU, and investment in communication.
F our internal videos: “Everyone mobilized”! These short films
showcased the first-hand accounts of experts invested in crisis
management, even though they are not part of the on-call teamof IRSN’s crisis organization. By showing multifaceted mobilization,
the films promoted the Institute’s collective strength and the powerof collaborative work.

AND AFTERWARDS...
The Ukrainian crisis, on the European continent, pursuing a dynamic that no
scenario had envisaged, is very different from that of the Fukushima-Daiichi
power plant which, in 2011, had driven IRSN to set up the ERC around theclock for a period of several weeks. The Japanese crisis, unlike other majorinternational crises in the history of civil nuclear power and safety, waslinked to a severe accident that simultaneously affected several reactors
on the same site. In Ukraine, no reactor suffered critical damage in 2022.
Nevertheless, a latent radiological risk, linked to acts of war targeted against
facilities scattered over a large territory or against the energy infrastructure,
has left a lasting threat over Ukraine and neighboring countries. This led
IRSN to remain mobilized or on active standby for 10 months in 2022:
an unprecedented situation. Given that the war is ongoing, the Institutewill continue to monitor the nuclear facilities and the environment inUkraine, Europe, and France for as long as necessary in 2023.
At the same time, feedback from this atypical crisis is already forthcoming.
Indeed, the analysis of events affecting nuclear facilities always teaches us
important lessons for improving safety and crisis management. Repeatedattacks on the Ukrainian nuclear sites, along with the recent Covid-19
health crisis, once again prove that the reality of a crisis challenges theimagination, and that crisis management plans, while very useful fororganizing quickly in the event of an alert, can never predict everything.
Nevertheless, even though the safety improvements for nuclear facilities
implemented in Europe – and more specifically in Ukraine – following
feedback from the Fukushima-Daiichi disaster were not designed to protectthese facilities in wartime, they have contributed directly to the robustnessof the power plants during this year of armed conflict. They have reduced
the risk of a severe accident caused by the loss of external power supply.
The exceptional situation of the crisis in Ukraine has also led IRSN toseek outside-the-box responses to build its resilience by drawing on theability of its multidisciplinary teams to adapt their efforts to the challenges.
Internally, within the Institute, this crisis has been a catalyst for adaptationand transformation. Externally, it has reaffirmed the importance of IRSN’srole as a technical expert providing support to the public authorities
in the context of international crisis management.

Christine Goudedranche• Crisis communication 
manager in the Communication 
Department• Crisis team member
for more than 10 years
in the “Communication”
Unit (CCOM)
Various positionsin the crisis pool:• Leader of the CCOM
• Technical secretary• Editor

PHOTO CREDITS© Fredrick Dahl / IAEA, Célia Goumard, Fedor Kozyr,Eloïse Lucotte, Noak / LeBarFloréal, Sylvain Renard,
Laurent Zylberman / Graphix-Images, Médiathèque IRSNDESIGN & EXECUTION

15

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