Examples of environmental harm in Ukraine | return to map
Name: Zaporizhzhia Nuclear Power Plant
Location: Enerhodar, Zaporizhzhia Oblast
CEOBS database ID: 10179
Context
Zaporizhzhia Nuclear Power Plant (ZNPP) is Europe’s largest; prior to February 2022 its six modern reactors provided around 25% of Ukraine’s electricity and the plant employed more than 11,000 staff.
It is the first operational nuclear power plant ever to be seized and militarily occupied during an armed conflict. Tangibly, this has disrupted Ukraine’s energy supply, but the bigger impact has been the weaponization of the perceived risk of imminent nuclear catastrophe. The dangerous situation has been discussed in the UN Security Council (UNSC) and along with the destruction of the Kakhovka Dam and reservoir, which ZNPP sits adjacent to, has been one of the most visible environmental stories of the invasion.
Timeline of key incidents
Countless important incidents have undermined the complex operation of ZNPP and only the most important ones are covered in brief here. Comprehensive timelines are provided by the International Atomic Energy Agency (IAEA), whose presence on site since September 2022 has been an important source of reliable information.
3rd March 2022
The seizure of ZNPP was initially obstructed by a civilian roadblock, which held back tanks and troops for two days. When forces reached the site, a two hour firefight with security personnel led to a fire in a training building and damage to the wall of reactor building 4. Following the seizure of the plant, Russia transferred its management to Rosatom, its state atomiс energy corporation.
Late July – early September 2022
On the 19th of July a drone attack on military equipment around 250 m away from reactor buildings marked a step change in risk. The incident followed international reports of the growing military presence at ZNPP, which was later supported by satellite imagery and social media footage. Shelling was reported at, around and from ZNPP. The apparent escalation led to meetings in the UNSC and a site visit by the IAEA.
The IAEA’s report detailed damage to: electrical transmission equipment, buildings and land in the area surrounding the spent fuel storage facility, the nitrogen-oxygen station, laboratories, chemical facilities and to radiation monitoring sensors. The damage to transmission lines and substation equipment disconnected ZNPP from the grid on several occasions. The plant requires power for critical safety functions and was forced to rely on backup diesel generators during these interruptions.
November 2022
Grid disconnections continued throughout October and early November 2022. Intense shelling occurred on the 19th and 20th November, with shells landing in the area around reactor building 4. During the event, damage was caused to condensate tanks, roads, railway tracks, an overpass, electrical connections to emergency generators and the roof of special building 2; but fortunately not to the containers of fresh nuclear fuel inside.
6th June 2023
The collapse of the Kakhovka Dam and rapid draining of the Kakhovka Reservoir affected the plant’s water supply to its cooling ponds. Although there was no immediate risk, water levels in the ponds began falling and were expected to last a matter of months. By September, groundwater wells had been drilled to supply cooling water, with maintenance work performed on the integrity of the ponds.
11th August 2023
Further shelling coincided with a UNSC meeting on ZNPP, with the damage resulting in a water leak at a steam generator in Reactor 4. The leak required that reactors 4, 5 and 6 be transitioned between hot and cold shutdowns,1 a complex emergency process that has repeatedly been necessary during the occupation.
Further attacks, power interruptions and safety incidents have occurred, especially in April 2024, but these are not presented here as they fall after our September 2023 operational security cut-off. We are tracking these incidents and hope to update this documentation when appropriate.
Damage assessment
The damage to the fabric of ZNPP has been relatively minor: holes in roofs, craters, damaged pipework and tanks. While individually not critical, collectively these pose serious risks.
Environmental harm assessment
Although no radiological releases have been reported, nuclear safety – as defined by the IAEA’s ‘Seven Pillars of Nuclear Safety and Security’ – has been compromised.
Breaches in physical integrity include damage to facilities housing radioactive waste as well as to switchyards, spray cooling ponds and power supply connections. Offsite power supply has been lost on numerous occasions. Safety and security systems have been undermined by: the loss of cooling waters; the presence of military vehicles in reactor turbine halls; ongoing munitions blasts; damage and unauthorised modifications to the dry spent fuel storage facility; damage to oil and condensate storage tanks; damage to the fire station; and ongoing maintenance challenges.
ZNPP’s logistical supply chain has been disrupted and, while the procurement of spare parts has been possible, non-critical maintenance tasks have been postponed. Chains of command and responsible parties in the event of an incident or accident are unclear and radiation monitoring data is not shared with the IAEA in real or near-real time. A temporary emergency plan was developed in March 2023, which was expected to be followed by a permanent plan in September 2024.
Communication broke down between the new ZNPP management and the Ukrainian state nuclear regulator. The plant was being run with a skeleton staff of 3-4,000 and operating staff reported serious fatigue and maltreatment. Remaining staff have faced increased workloads, the constant stress of working under military occupation and demands and threats from management.
Longer-term implications
The most serious radiological risk at ZNPP would be a meltdown at one or more of the reactors, which could be caused by several factors.2 A meltdown would have the potential for a regional-scale radiation release, especially if the reactors were operational. To avoid catastrophic incidents the IAEA developed ‘five concrete principles’ for the conflict parties to observe. This replaced an earlier attempt to develop a demilitarised zone around the plant.
Though operational, real-time radiation monitoring data has been unavailable from the site’s automated system since the occupation began. Off-site radiation monitoring has become more important, whether government-backed or by civil society. However, there remain gaps in coverage in occupied areas of Zaporizhzhia and Kherson oblasts. The ongoing conflict means that implementing an effective emergency response in the event of a serious incident will be difficult.3
The situation at ZNPP has led to reflections on the safety of nuclear power, especially in war, and the situation has challenged existing international law.
Dis/mis-information watch
Inevitably there have been recurring periods of speculation and public concern over potential risks. Many of these have involved disinformation, especially in the pro-Russian media.
External resources
Nuclear Safety, Security and Safeguards in Ukraine | IAEA
A Nuclear Power Plant as Launch Pad: Analysis of the occupation of Zaporizhzhia NPP by Russian armed forces and Rosatom and the role of the IAEA | Greenpeace Germany
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- According to the IAEA – Reactor 5 had been in hot-shutdown for many months and was moved into cold-shutdown for maintenance. This meant moving Reactor 4 into hot shutdown in its place. With the damage to the steam generator in Reactor 4, it was moved to cold shutdown. This meant that Reactor 6, which had been in cold shutdown for months, was switched into hot shutdown, so steam could continue to be generated. The transition and balance between shutdowns is a complex component of safety management.
- The primary risks of a catastrophic accident are associated with the prolonged loss of external power and cooling water, or with inexperienced operators inadvertently triggering severe accident sequences while managing the status of the reactors. These risks would be increased should Russia attempt to resume power generation. Beyond the reactors themselves, the site holds substantial quantities of spent fuel, damage to casks and the storage areas could create a localised contamination incident.
- Ukrainian (SNRIU, UHMI) and international organisations (CTBTO) have undertaken dispersion modelling of radioactive plumes from a potential incident at the site. Such models can be complex due to uncertainties related to the meteorology data used and model representations of physical processes, with better results arising from using ensemble approaches. Communication of these uncertainties will be important in the event of a radiation release.
