INFORMATION NOTE
Update on the risk situation regarding
Ukrainian nuclear facilities

Date: 07 March 2022

Status on 7 March 2022
The invasion of Ukraine by Russian troops demands careful monitoring of its nuclear installations. Ukraine has
15 Russian-designed VVER reactors in service, research reactors, storage sites for sources and waste, as well as
the reactors at the Chernobyl site, the last of which was shut down in December 2000, and the various facilities
required to manage the accident site.
The major risk in terms of radioactive release concerns the power reactors in operation and the spent fuelpools1. The 1,000 MWe reactors2 have concrete containment structures. In these facilities, the spent fuel pools
are located inside the containment.
According to the information available to the Institute, the fire that occurred on the night of 3-4 March 2022 at
the Zaporizhzhya nuclear power plant site did not cause any deterioration of reactor safety. On the morning of4 March, the Institute received confirmation from SNRIU that the electric power supply to the plant had notbeen damaged by the fire. This power supply is necessary to keep the facilities in a safe state, whether they arein operation or shut down. In this respect, the safety of Ukrainian power plants has been significantly improved
since the accident at the Fukushima Daiichi plant. The plants are equipped with emergency electric powersources (4 generators per reactor, one of which is bunkered), and mobile equipment that can be connected to
the reactor concerned. The fuel reserves for the diesel generators are sufficient to provide cooling for seven toten days, after which refuelling will be necessary.
There have also been reports of damage to the containment structure of reactor 1, which had been shut down
before the conflict began. This information has not been confirmed; it is more likely that the shots fired
damaged a footbridge near the building. Regarding the operational status of the plant, the Ukrainian nuclear
safety authority (SNRIU) reports that two of the plant’s six reactors are in service.
Concerning the environmental radioactivity monitoring networks, the Ukrainian national network isoperational, with the exception of a few stations. Based on the information collected by IAEA from SNRIU andthe data transmitted by the measurement network, there has been no increase in radioactivity since the firethat night. The absence of radioactive release is also confirmed by the monitoring networks of the countries
bordering Ukraine, which do not indicate any abnormal increase.

1 The spent fuel pool contains fuel assemblies used in the reactor core. They are stored in this pool for a few years before beingtransported to other pools.
2 This means all Ukrainian reactors except Rovno 1 and 2, which have a capacity of 400 MWe.

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INFORMATION NOTEANNEXE 1
Assessment of the possible consequences of loss of electric power
supplies to the Zaporizhzhya plant
IRSN has evaluated the orders of magnitude of radioactive releases associated with different severe accident
scenarios that could occur in a reactor at the plant.
For power reactors in operation, the most likely scenario in an armed conflict situation is the loss of the power
grid. Such an event would only affect the safety of the reactor if the emergency power supply systems (dieselgenerators and mobile equipment available on site) were lost or no longer supplied with fuel. Therefore, in theabsence of a direct attack on the facility, the safety of the facility should be manageable for a few days
following the loss of off-site power supplies.
In view of the uncertainty associated with the current situation, IRSN has estimated the consequences of total
loss of the plant’s normal and emergency power supplies. This scenario may lead to a loss of the coolingsystems of the reactor core and the spent fuel pool. This loss of cooling would result in meltdown of the core
and the spent fuel in the pool.
For this scenario, the radiological consequences could justify the implementation of protective measures forthe local population. More precisely, the areas potentially affected by an evacuation of the population may
cover distances of several kilometres from the release point, based on the reference values indicated in
France’s current health code (50 mSv in effective dose). Sheltering (10 mSv in effective dose) and theadministration of stable iodine (50 mSv thyroid equivalent dose) may be required over distances ofapproximately 20km.
If the cooling systems are not recovered, the increase in heat generated within the containment would requiredepressurisation of the structure, which would result in more releases into the environment. Assuming
weather conditions similar to those currently observed in Ukraine, the aforementioned perimeters forevacuation, sheltering and the administration of stable iodine could be extended to several tens of kilometres.
In any case, no significant effects are to be expected on the French territory.
It is important to remember that these are working hypotheses. In the event of an actual accident involving a
Ukrainian nuclear facility, a more accurate assessment of the releases, based on data available in the facility
and weather conditions at the time of the event, would be carried out.

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INFORMATION NOTEANNEXE 2
Continuous environmental radioactivity monitoring by IRSN in Ukraine
1. Available data
In view of the situation in Ukraine, IRSN has been monitoring radioactivity levels in Ukraine and neighbouring
countries since 24 February 2022.
This monitoring is mostly based on data from automatic stations that measure ambient radioactivity in the air(ambient gamma dose equivalent rate or, more simply, ambient dose rate, expressed in nanosievert per hour(nSv/h)). The data used by IRSN come from the following sources in particular:•••the European EURDEP network (EUropean Radiological Data Exchange Platform https://remap.jrc.ec.europa.eu/Simple.aspx). This network presents the dose equivalent rate datasubmitted by the authorities of EU Member States;
the Ukrainian state agency that manages the Chernobyl exclusion zone (DAZV Ecocentre https://dazv.gov.ua/en);
The SaveEcoBot website (www.saveecobot.com), which aggregates data from 9 operators3, including
Ecocentre, Ukrainian power plant operators and EURDEP.

These different data sources may overlap. It is important to note that, due to the current conditions in Ukraine,
particularly local power cuts, some stations may have ceased to transmit or may be communicating unreliabledata.

3 EURDEP, Ecocentre, Ukrainian Hydrometeorological Centre, operators of Zaporizhzhya, Khmelnitsky, Rivne, South Ukrainian Nuclear

Power Plant (SUNPP), Main Center of Special Monitoring and Department of Ecology and Natural Resources of the Kiev region.

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INFORMATION NOTE2. Radiological status of the territory of Ukraine
Ukraine has several nuclear sites:
Site Facilities
Chernobyl

Waste treatment and storage facilities 1 damaged
RBMK reactor (sarcophagus)
3 RBMK reactors under decommissioning
Nuclear power plant (4 VVER reactors)
Nuclear power plant (2 VVERs)
Nuclear power plant (3 VVERs)
Nuclear power plant (6 VVERs)
Research reactor
Research reactor
Storage and treatment of radioactive waste
Storage and treatment of radioactive waste
Storage and treatment of radioactive waste
Storage and treatment of radioactive waste
Storage and treatment of radioactive waste
Storage and treatment of radioactive waste
4RivneKhmelnitsky
South Ukraine
Zaporizhzhya
Sebastopol
Kiev
Kharkiv
OdessaLviv
Dnipropetrovsk
Donetsk

5Figure 1: Map of nuclear facilities in Ukraine.

4 RBMK reactors are Russian-designed pressure tube reactors for industrial power generation and plutonium production.
5 VVER reactors are Russian-designed pressurised water reactors based on two different technologies, 440 and 1,000 MWe respectively.

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INFORMATION NOTE

Texte FR
LégendeSites nucléaires (Ukraine)
NPP (definitely closed)
NPP
Nuclear waste storage
Research reactor
Rovno NPP : 2VVER-440 / 2VVER-1000
South Ukraine : 3 VVER-1000
Khmelnitski : 2 VVER-1000
Zaporoshye : 6 VVER-1000
Lviv (SISP)
Rovno
Khmelnitski
Chernobyl
Kiev (KINR)
Kiev (SISP)
South Ukraine
Odessa (SISP)
Dnipro (SISP)
Kharkiv (SISP)
Zaporozhye
Donetsk (SISP)
Sebastopol

Texte EN
LegendNuclear sites (Ukraine)
NPP (definitely closed)
NPP
Nuclear waste storage
Research reactor
Rovno NPP: 2 VVER-440 / 2VVER-1000
South Ukraine: 3 VVER-1000
Khmelnitski: 2 VVER-1000
Zaporoshye: 6 VVER-1000
Lviv (SISP)
Rovno
Khmelnitski
Chernobyl
Kiev (KINR)
Kiev (SISP)
South Ukraine
Odessa (SISP)
Dnipro (SISP)
Kharkiv (SISP)
Zaporozhye
Donetsk (SISP)
Sebastopol

The Ukrainian nuclear safety authority (SNRIU) has informed IAEA that the nuclear power plants are still
operating safely and that the radioactivity monitoring systems are operational (although electric power or grid
outages may occasionally interrupt data transmission).
All the radioactivity measurement stations around the nuclear power plants or other sites are indicating
normal values, at around background noise6.

2.1 Radiological status in the Zaporizhzhya site environment
The stations of the Ukrainian national monitoring network have not indicated any increase in radioactivity
around the Zaporizhzhya nuclear power plant site since the beginning of the conflict until today.

6 Around 100 nSv/h (source: EURDEP).

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INFORMATION NOTE

Figure 2: Beacons of the Ukrainian national network around the Zaporizhzhya site.
Texte FR
LégendeZaporozhye NPPBalises_nationales
RéseauUkraine (UHC)
Kryvyi Rih
KomisarivkaLoshkarivka
Velyka Oleksandrivka
Nikopol
Nova Kakhovka
Askania-Nova
Nyzhni Sirohosy
Zaporozhye
DniproSynelnikove
Zaporizhzhia
Pryshyb
Melitopol
Botievo
Huliaipole
Kyrylivka

Texte ENLegend
Zaporozhye NPP
National_beacons
Network
Ukraine (UHC)
Kryvyi Rih
Komisarivka
Loshkarivka
Velyka Oleksandrivka
Nikopol
Nova Kakhovka
Askania-Nova
Nyzhni Sirohosy
Zaporozhye
DniproSynelnikove
Zaporizhzhia
Pryshyb
Melitopol
Botievo
Huliaipole
Kyrylivka

Furthermore, SNRIU confirmed to IAEA that the operator's stations did not indicate any increase in radioactivity
following the fire at the site on the night of 3-4 March.
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INFORMATION NOTE

2.2 Radiological status in the Chernobyl exclusion zone (Ukrainian sector)
During the night of 24-25 February 2022, many of the monitoring stations in the Chernobyl exclusion zone
indicated peaks in ambient gamma equivalent dose rate significantly above the levels (background) usually
measured by these stations.

Figure 3: Map of the measuring beacon locations in the Chernobyl exclusion zone.
Texte FR
Texte EN
LégendeLegendBalises fixes (irradiation)
Fixed beacons (irradiation)
Balises de la Zone d’Exclusion de Tchernobyl
Beacons of the Chernobyl Exclusion Zone
Balises de la Zone d’Exclusion de Tchernobyl
Beacons of the Chernobyl Exclusion Zone

However, it is worth noting the large discrepancies in the measurements available in the area: some stations
detected increases but others did not, and all suffered data transmission interruptions (the cause of which isunknown) lasting for several hours.
In view of the elements at its disposal, and without ruling out the hypothesis that radioactive material was put
back in suspension by the nearby passage of heavy military equipment, the explanation preferred by IRSN is atechnical malfunction of these stations. This analysis is supported by IRSN's technical discussions with its
international partners and the International Atomic Energy Agency (IAEA). The latter also indicated, in a press
release issued by its Director General on 28 February 20227, that the data at its disposal, communicated by theUkrainian safety authority (State Nuclear Regulatory Inspectorate of Ukraine - SNRIU), indicated levels ofradioactivity consistent with the background noise usually observed in the area.
It should be noted that since 1 March, the data collected by the network operated by Ecocentre are nolonger available. However, the Ukrainian national network station in the area continues to transmit
measurements indicating that the dose rate is at the usual level of background noise in this area.

7 Update 4 - IAEA Director General Statement on Situation in Ukraine, https://www.iaea.org/newscenter/pressreleases/update-4-iaea-

director-general-statement-on-situation-in-ukraine
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INFORMATION NOTE

3. Radiological status in countries bordering UkraineIRSN has also continued its discussions with its European partners and IAEA, and regularly monitors the data
provided by the countries bordering Ukraine (Figure 3). In the event of a major event involving a Ukrainian
nuclear facility, these countries would detect an increase in radioactivity levels well before any radioactivity
reached France.
No abnormal increase in radioactivity related to the situation in Ukraine has been observed in these countries.

Figure 4: Dose equivalent rate monitoring stations in countries bordering Ukraine transmitted to theEURDEP network, excluding Russia.

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