Ukraine: Current status of nuclear power installations

Last updated: 12 October 2023

Over a year after the war in Ukraine began, the NEA continues to collect information from verifiable and reliable sources to support its members’ efforts to maintain an understanding of the state of nuclear safety and radiological protection in that country. The OECD has continued to further broaden, deepen and strengthen its engagement and co-operation with Ukraine. The NEA, in partnership with the United Kingdom, has recently launched an NEA-Ukraine Visiting Experts Programme, which will bring Ukrainian nuclear energy experts to the Agency.

Because our Ukrainian colleagues are faced with a highly uncertain, ever-changing and very challenging situation it is to be expected that obtaining detailed information on a regular basis may not be possible.

Electricity grid

The electricity grids of Ukraine and Moldova were successfully synchronised with the Continental European Grid on 16 March 2022.

Nuclear power plants

In Ukraine 15 pressurised water reactors of Russian VVER design are operated by the State Enterprise National Nuclear Energy Generating Company “Energoatom” at four plants. These plants operate under nuclear safety regulations implemented by the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU).

Zaporizhzhia nuclear power plant has six reactors.

4 October: The Zaporizhzhia nuclear power plant (ZNPP) restarted Unit 4 to generate steam for safety systems, following repairs to address a water leak. Unit 4 had been shut down after a leak was found in a steam generator pipe weld. With the pipe now repaired and tested, Zaporizhzhia will transition Unit 4 from cold to hot shutdown, allowing it to produce steam again. Unit 6, which had been providing steam since mid-August, will now return to cold shutdown.
29 September: With the completion of an eleventh groundwater well, the ZNPP is now able to supply around 250 cubic metres of water per hour. This is the level estimated to be necessary to maintain the level of the 12 sprinkler cooling ponds used to cool the six reactors and spent fuel stored at the plant. The Ukrainian authorities report that the level of the cooling pond remains stable.
22 September: A tenth groundwater well was completed, bringing the plant closer to a longer-term solution for the provision of cooling water to reactors in a shutdown state. Over 200 m³ of water per hour can now be supplied to the sprinkler ponds that cool the ZNPP’s six reactors and spent fuel. The wells were bored following the destruction of the Nova Kakhovka dam downstream from the site on 6 June and the subsequent draining of water from the Kakhovka reservoir.
22 September: A significant number of staff are reported to have left the ZNPP since the start of the war, including licensed operators from the main control rooms. IAEA observers at ZNPP were informed that recruitment of additional staff from Russian nuclear power plants is ongoing and that these staff are being trained and licensed to operate the plant under Russian Federation regulations.
15 September: A further two groundwater wells to supply the sprinkler ponds that cool the six reactors and spent fuel were brought on line, bringing the total of new wells to nine. The water supply situation at the plant will be reassessed once a tenth well has been constructed in order to assess whether more will be needed.
8 September: ZNPP staff indicated that there were now seven wells operating at the site supplying just over half of the water currently needed (250 m³ per hour) to maintain the cooling water in the plant’s sprinkler ponds. The remaining volume of cooling water is currently pumped from the site’s drainage system. As a result of the new wells, the ZNPP staff reported that the height of the groundwater had only declined by a very minor level.
4 September: Each ZNPP reactor has three separate and independent redundant systems (commonly called “safety trains”) that together comprise the unit’s safety systems. Safety trains are normally in stand-by mode, ready to activate if needed to maintain the reactor unit’s safety. A single safety train is capable of maintaining the reactor unit’s safety. A water leak was detected in a recirculation valve of one system of one safety train of the ZNPP Unit 5. In order to repair the valve, one safety train of Units 5 and Unit 6 had to be placed offline. Once the valve had been repaired, the Unit 6 safety train was returned to standby mode, while the Unit 5 safety train was kept offline for maintenance.
1 September: ZNPP staff reported that four groundwater wells were now in operation, out of a total of 10-12 wells planned to be drilled around the plant’s sprinkler ponds. The wells are intended to become the main source of cooling water for the six shutdown reactor units and spent fuel pools, following the destruction of the Nova Kakhovka dam downstream from the site.
22 August: ZNPP began pumping water from a new groundwater well to serve its cooling needs. The well was bored following the collapse of the Nova Kakhovka dam downstream from the site on 6 June and the subsequent draining of water from the Kakhovka reservoir. The new well was reportedly providing about 20 m³ of water an hour. It is planned to drill an additional 10-12 wells at the site.
13 August: ZNPP reactor Unit 6 reached a hot shutdown state to generate steam for various nuclear safety purposes at the plant, replacing Unit 4.
11 August: ZNPP reactor Unit 4 was moved from hot shutdown to cold shutdown following the detection of a water leak in one of its four steam generators. To continue production of steam at the site preparations to move Unit 6 into hot shutdown mode were begun. The 750kV power line providing ZNPP with the electricity needed for reactor cooling and other essential nuclear safety and security functions was disconnected twice in the course of the day, meaning that the plant had to rely on its only remaining 330 kV backup power line to supply the required electricity.
29 July: The planned transition of ZNPP Unit 4 to hot shutdown was completed, while unit 5 transition to cold shutdown. The planned maintenance activities include inspecting and testing safety systems which protect the reactor and its fuel as well as cleaning of the heat exchanger.
12 July: Preparations to move the ZNPP reactor Unit 4 from a cold shutdown state to hot shutdown began. The ZNPP unit 5 is currently in hot shutdown, a state used to generate steam for various safety purposes that include the processing of liquid radioactive waste collected in storage tanks. Once in cold shutdown preventive maintenance activities that can only be carried out while in cold shutdown will be performed. All other units remained in cold shutdown. The SNRIU, Ukraine’s national regulator, issued regulatory orders on 8 June to limit the operation of all six units on the site to cold shutdown state only.
5 July: The main 750 kilovolt (kV) power line providing the ZNPP with the electricity needed for reactor cooling and other essential nuclear safety and security functions was disconnected at 01:21am local time on 4 July. A recently reconnected 330 kV line prevented full loss of external power until the restoration of the 750 kV line some 12 hours later.
3 July: A 330 kV line to help supply the ZNPP’s external electricity needs for the ZNPP was reconnected to the plant on 1 July. This line supplements the existing 750 kV line currently meeting these needs. Before the war began in February 2022, four such 750 kV lines were available to the plant.
21 June: Some of the cooling water needs for the ZNPP were reportedly being met using a discharge channel of the Zaporizhzhia Thermal Power Plant (ZTPP). This water was used to supply the ZNPP’s spray ponds which cool the six reactors in shut down mode and the plant’s spent fuel storage. The ZNPP spray ponds have also been replenished using a drainage system fed by underground water near the ponds.
8 June: The SNRIU issued a regulatory order for the ZNPP reactor 5 to be placed into a cold shutdown state. The unit is currently in hot shutdown to produce process steam for such site operations as the treatment of liquid radioactive waste. Such waste is collected from all six reactors, even when in cold shutdown.
6 June: Water levels in the reservoir that supplies the ZNPP fell throughout the day following the breach of the Nova Kakhovka dam downstream from the facility. Onsite back-up options remain available and are estimated to be sufficient for up to several months. Water is needed for residual heat removal from the reactors and used fuel ponds, as well as to cool emergency diesel generators when they are in operation.
22 May: The National Nuclear Energy Generating Company Energoatom reported that the 750 kV main external power line providing the electricity needed for reactor cooling and other essential nuclear safety and security functions at ZNPP was cut. Power supply to the safety systems was provided by emergency diesel generators until the connection to the electricity grid was restored some five hours later.
12 May: IAEA observers at ZNPP noted fewer on-site staff, but confirmed that essential personnel working in the main control rooms continued to be available and present during each shift.
6 May: Both the IAEA and the National Nuclear Energy Generating Company “Energoatom’ reported that the evacuation of residents from the nearby town of Enerhodar, where most of the ZNPP staff live, had begun. Operating staff were not being evacuated and site management stated that it has sufficient staff for the safe operation of the plant. IAEA observers at ZNPP reported hearing shelling on a regular basis.
21 April: ZNPP Unit 6 was placed in cold shutdown, with only Unit 5 in hot shutdown to produce hot water and steam for the site.
8 April: IAEA observers at ZNPP reported two landmine explosions outside the perimeter fence.
22 March: The monthly test performed at ZNPP Unit 4 for the loss of off-site power saw the emergency diesel generators successfully started.
9 March: The ZNPP suffered a complete loss of external power between 5 a.m. and 4 p.m., forcing it to rely on emergency diesel generators for reactor cooling and other essential nuclear safety and security functions during this time.
26 January 2023: IAEA observers at the plant reported they heard eight strong detonations at around 10am local time, causing office windows at the plant to vibrate.
19 January: IAEA estimates of the number of employees now working at the plant are around 3 000 – down from around 10 000 before the conflict.
7 January 2023: The ZNPP 330 kilovolt (kV) back-up power line, which had been disconnected once more due to damage caused by shelling on 29 December, was reconnected. The plant continued to receive the electricity it needed for essential safety and security functions from a 750 kV main external power line.
30 December 2022: Nine mobile diesel-fuelled boilers with power in the range of 1-6.5 megawatts (MW) have been delivered to the plant to provide heating to the ZNPP site and to Enerhodar. The plant also has 20 diesel backup generators to supply the site with the electricity needed for all safety related equipment.
14 December 2022: IAEA observers at ZNPP reported that the plant’s 330 kilovolt (kV) back-up power line to the electricity grid, which had been disconnected the previous day due to shelling, was now restored.
24 November, 2022: Zaporizhzhya Nuclear Power Plant (ZNPP) reported that the facility’s external power connection had been re-established, a day after it was disconnected.
19 November, 2022: Shelling caused damage in several places at ZNPP, including a radioactive waste and storage building, cooling pond sprinkler systems, an electrical cable to one of the diesel generators, condensate storage tanks, and to a bridge between a reactor and its auxiliary buildings.
3 November, 2022: The plant’s connection to both its main 750 kilovolt (kV) power line and its back-up off-site power supplies from a 330 kV line were cut. Diesel generators started operating automatically to supply the plant with the electricity it needs for the cooling of the units in cold shutdown.
28 October, 2022: Negotiations by the International Atomic Energy Agency with Russia and Ukraine, to establish a nuclear safety and security protection zone around the facility, are ongoing.
19 October, 2022: According to reports from Ukraine’s State Enterprise National Nuclear Energy Generating Company “Energoatom”, the Zaporizhzhia nuclear power plant’s Head of Information Technology, Oleh Kostyukov, and Assistant to the plant’s Director, Oleh Oshek, were detained by Russian personnel on Monday 17 October.
18 October, 2022: The Zaporizhzhya nuclear power plant’s last remaining operating 750 kilovolt (kV) power line was reconnected on October 18. The connection has been disrupted three times in ten days.
4 October, 2022: Ukraine’s State Enterprise National Nuclear Energy Generating Company “Energoatom” have confirmed that Director-General of Zaporizhzhia Nuclear Power Plant (ZNPP), Ihor Murashov, who had previously been detained on Friday, 30 September by Russian personnel, has been released.
3 October, 2022: According to reports from Ukraine’s State Enterprise National Nuclear Energy Generating Company “Energoatom”, the Director-General of Zaporizhzhia Nuclear Power Plant (ZNPP), Ihor Murashov, has been detained by Russian personnel. No further information is yet available about this matter.
There have also been reports of landmine explosions at the ZNPP. A blast on 30 September 2022 damaged a 6 kilovolt (kV) cable, which provides power for some plant operations, just outside the ZNPP perimeter fence. According the IAEA, the explosion did not directly affect the plant’s safety systems.
18 September, 2022: A backup power line to the Zaporizhzhia nuclear power plant was disconnected for reasons as yet unknown. The line is used to supply the plant with the electricity necessary for the cooling of the units in cold shutdown, should the regular line fail.
16 September, 2022: A regular 750/330 kilovolt (kV) power line to the national grid was restored and was being used to provide the plant with power required for its safety functions.
13 September, 2022: The last reactor at the Zaporizhzhia nuclear power plant that had continued operating has now entered a cold shutdown state. The reactor was shut down after the restoration of a 330 kilovolt (kV) power line which enabled the plant to access electricity from the grid. A 750/330 kV line has now also been restored and it is being used to provide the plant with power required for its safety functions, with the restored 330 kV line held in reserve. The International Atomic Energy Agency (IAEA) reports that the two restored lines can both receive power from the grid through the switchyard of a nearby thermal power station.
12 September, 2022: Based on information provided by Energoatom NAEC to the SNRIU, in the early hours of 11 September Unit No. 6, the last operating reactor at the site, was disconnected from the power grid. Shortly afterwards, a back-up power line was restored, allowing for an external electricity supply to enable the cooling and transition to the "cold stop" state.
7 September, 2022: Renewed shelling in and around Zaporizhzhia damaged a back-up power line between the power plant and a nearby thermal power station.
6 September, 2022: The IAEA published a report on the current state of the plant’s safety and security.
29 August, 2022: An IAEA mission to the Zaporizhzhia nuclear power plant took place.
26 August, 2022: As a result of the power outages, the last two operating reactor units were disconnected from the electricity grid and their emergency protection systems were triggered; all safety systems remained operational.
Plant staff continued carrying out work on connecting power units No. 5 and No. 6 of the Zaporizhzhia nuclear power plant to the electricity grid, connecting one on 26 August.
25 August, 2022: Subsequent reports have highlighted that two of the four high voltage (750 kV) offsite power lines to the site were damaged. Another high voltage line is on standby. The operator informed the IAEA that the plant’s off-site power needs could be provided with one power line and that diesel generators were also ready and functional to provide back-up power if required. This line was damaged on 25 August.
25 August, 2022: Ukraine’s nuclear operator, Energoatom reports that its staff continue to operate the facility, but under extremely stressful conditions. Additionally, the nuclear safety regulator SNRIU has indicated that it is no longer in a position to oversee nuclear safety at the site.
4 March, 2022: The Zaporizhzhia nuclear power plant was shelled on the night of 4 March but the resulting fire was extinguished and had no impact on essential equipment. The plant management is now under orders from the commander of the Russian forces that took control of the site.

Khmelnytskyi nuclear power plant has two existing reactors and two reactors under construction.

23 January 2023: the IAEA and Ukrainian authorities announced that the IAEA Support and Assistance Mission in Khmelnytskyi (ISAMIK) had begun its work at the plant.
20 January 2023: the IAEA announced that its Support and Assistance Mission in Khmelnytskyi (ISAMIK) will begin its work at the plant in the coming days.
23 December 2022: The IAEA announced plans to deploy a team to the plant to provide technical support and assistance as needed.
9 December 2022: An IAEA delegation visited the plant to assess its nuclear safety and security situation as well as any material needs.
23 November, 2022: National operator Energoatom reported that due to a decrease in the frequency in the power system of Ukraine the Rivne, South Ukraine and Khmelnytskyi nuclear power plants were all automatically disconnected from the grid.
15 November, 2022: Khmelnytskyi nuclear power plant’s connection to the Ukrainian power grid was completely lost as a result of missile strikes. Units 1 and 2 were shut down and switched to providing their own needs from the backup diesel generators.
September 26, 2022: The Khmelnytsky nuclear power plant was inspected between 24-25 September by the IAEA within the framework of the Agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons. The inspection of the absence of undeclared nuclear material was carried out by the Agency's inspectors with the participation of the State Nuclear Regulation inspector. The purpose of the inspection was to verify the absence of undeclared nuclear material and information on the design of the nuclear installation provided to Ukraine in accordance with the Agreement.
13 September, 2022: Two reactors were in operation on 13 September
12 September, 2022: The Khmelnytsky nuclear power plant was inspected by the IAEA within the framework of the Agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons. The inspection was carried out by the IAEA with the participation of the inspector of the State Atomic Energy Regulatory Commission. The purpose of the inspection was to verify the absence of undeclared nuclear material and information on the design of the nuclear installation provided to Ukraine in accordance with the Agreement.
11 March, 2022: Khmelnytskyi NPP was inspected by the International Atomic Energy Agency on 11 March under the agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons. The inspection was carried out by inspectors of the Agency with the participation of an SNRIU inspector. The purpose of the inspection was to verify the absence of undeclared nuclear material and information on the design of the nuclear installation provided to Ukraine in accordance with the Agreement.

Rivne nuclear power plant has four reactors.

10 March 2023: The Rivne nuclear power plant was inspected between 8-9 March by the IAEA within the framework of the Agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons.
3 February 2023: the first rotation of the IAEA Support and Assistance Mission in Rivne (ISAMIR) was completed.
25 January 2023: Rivne Nuclear Power Plant was inspected by the IAEA under the agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons. The inspection was carried out by inspectors of the Agency with the participation of an SNRIU inspector. The purpose of the inspection was to verify the absence of undeclared nuclear material and information on the design of the nuclear installation provided to Ukraine in accordance with the Agreement.
17 January 2023: the IAEA Support and Assistance Mission in Rivne (ISAMIR) began its work at the plant.
23 December: The IAEA announced plans to deploy a team to the plant to provide technical support and assistance as needed.
9 December: An IAEA delegation visited the plant to assess its nuclear safety and security situation as well as any material needs.
24 November, 2022: The facility’s connection to the electricity grid was re-established.
23 November, 2022: National operator Energoatom reported that due to a decrease in the frequency in the power system of Ukraine, the Rivne, South Ukraine and Khmelnytskyi nuclear power plants were all automatically disconnected from the grid.
15 November, 2022: Rivne nuclear power plant’s connection to one of its 750 kV power lines was lost. As a result, the plant reduced its power output and one of its four units was automatically disconnected; the plant increased the power of one of its other units to continue supplying electricity to the Ukrainian network at the same rate.
13 September, 2022: Three of these reactors were in operation as of 13 September.
22 July, 2022: Rivne NPP was inspected by the IAEA under the agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons. The inspection was carried out by inspectors of the Agency with the participation of an SNRIU inspector. The purpose of the inspection was to verify the absence of undeclared nuclear material and information on the design of the nuclear installation provided to Ukraine in accordance with the Agreement.

South Ukraine nuclear power plant has three reactors.

29 September 2023: Spare parts for the emergency diesel generators of the South Ukraine nuclear power plant, provided under arrangements agreed on 5 May between the IAEA, France and Energoatom, arrived at the site. The spare parts are essential for the maintenance and functionality of the diesel generators, which provide the electricity essential for the plant’s safety systems should the site to lose offsite power. The first delivery took place in June.
2 June 2023: Following a disturbance in the electricity grid one reactor unit at South Ukraine NPP experienced an emergency shutdown on 22 May. The plant continued to receive off-site power and by 2 June had returned to full power.
16 January 2023: The IAEA Support and Assistance Mission in South Ukraine (ISAMISU) began its work at the plant.
23 December: The IAEA announced plans to deploy a team to the plant to provide technical support and assistance as needed.
2 December: An IAEA delegation visited the plant to assess its nuclear safety and security situation as well as any material needs.
25 November, 2022: The facility’s connection to the electricity grid was re-established.
23 November, 2022: National operator Energoatom reported that due to a decrease in the frequency in the power system of Ukraine, the Rivne, South Ukraine and Khmelnytskyi nuclear power plants units were all automatically disconnected from the grid.
15 November, 2022: South Ukraine nuclear power plant’s connection to the Ukrainian power grid was completely lost as a result of missile strikes.
3 November, 2022: South Ukraine nuclear power plant lost its connection to one of three 750 kV lines used to provide power to the grid. As a result, the site reduced the power of one of its three operating reactors by 50%.
19 September, 2022: Shelling caused an explosion near the plant, impacting three power lines, but not those connecting the plant to the grid, and damaging windows at the site. All three reactors remained in operation.
13 September, 2022: Three of these reactors were in operation .

Chernobyl exclusion zone

The Chernobyl nuclear power plant consisted of 4 operating units and 2 under construction at the time of the accident in April 1986 in Unit 4. It is also the site for an Interim Spent Fuel Facility and a Central Spent Fuel Facility.

23 February 2023: The Chernobyl nuclear power plant site was inspected between 20-22 February by the IAEA within the framework of the Agreement between Ukraine and the IAEA in connection with the Treaty on the Non-Proliferation of Nuclear Weapons.
20 February 2023: the first rotation of the IAEA Support and Assistance Mission in Chornobyl (ISAMICH) was completed.
18 January 2023: the IAEA Support and Assistance Mission in Chornobyl (ISAMICH) began its work at the site.
2 December 2022: An IAEA delegation visited the site during the week of 25 November to provide on-site assistance and support in nuclear safety and security.
11 May, 2022: Remote transmission of safeguards data from the plant to the IAEA was fully re-established and radiation detectors were once again transmitting data from the area around the plant.
Ukraine informed the IAEA that during the occupation the site’s analytical laboratories for radiation monitoring had been destroyed and analytical instruments stolen, broken or otherwise disabled.
31 March, 2022: The Russian forces that had been in control of the Chernobyl Nuclear Power Plant (NPP) since 24 February had, in writing, transferred control of the NPP to Ukrainian personnel.
13 March, 2022: The State Enterprise National Nuclear Energy Generating Company Energoatom announced that two of the damaged electricity lines were now repaired and delivering all required off-site power to the Chernobyl plant.
9 March, 2022: The SNRIU informed international partners that the Chernobyl plant had been disconnected from the electricity grid and lost its supply of external power. The SNRIU reported that backup diesel generators were running and had 48 hours of fuel.
27 February, 2022: No increase in ambient dose rate has been detected in European countries, via the European Radiological Data Exchange Platform (EURDEP).
25 February, 2022: Following reports of higher radiation measurements at the Chernobyl site, Ukraine’s regulatory authority stated that they may have been caused by heavy military vehicles stirring up soil still contaminated from the 1986 accident. The readings reported by the regulator – of up to 9,46 microSieverts per hour – are low and remain within the operational range measured in the Exclusion Zone since it was established, and were therefore judged by the IAEA to not pose any danger to the public.
Unit 1 is being decommissioned; Unit 2 was closed in March 1999; Unit 3 was closed in December 2000; Unit 4, the site of the accident, was initially protected by a Sarcophagus. A New Safe Confinement was built to enclose the existing sarcophagus and moved into position in 2016; Units 5 and 6 were under construction at the time of accident, but were never finished.
Construction was completed of an Interim Spent Fuel Storage Facility in 2017. The facility stores and processes spent fuel assemblies from Units 1, 2, and 3.
The Central Spent Fuel Storage Facility (CSFSF), is a dry storage site for used nuclear fuel assemblies from the reactors at Khmelnytskyi, Rivne and South Ukraine.

National Science Center, Kharkov Institute of Physics and Technology

The Kharkov Institute of Physics and Technology is the site of an experimental nuclear reactor used for research and to produce isotopes for medical and industrial use. The installation was placed in a deep subcritical state (“long-term shutdown”) mode on 24 February 2022.

10 November, 2022: An IAEA mission to the Institute found that while it had been heavily damaged by shelling, there was no indication of any radiological release or diversion of declared nuclear material.
6 March, 2022: Information received from the State Nuclear Regulatory Inspectorate of Ukraine is that the facility was damaged by shelling on 6 March and 25 June but did not cause any increase in radiation levels at the site. Initial reports were that a substation was destroyed; cables for the air conditioner cooling systems of the linear accelerator cluster gallery were damaged, and that heating of the entire complex was damaged.
25 June, 2022: Additional damage to the buildings and infrastructure of the site occurred affecting the ventilation systems of the special ventilation system and the main building of the installation, the cooling system of the accelerator’s klystron gallery, the emergency power supply system diesel generators and the cladding of the installation’s main building.

State Interregional Specialised Plants for Radioactive Waste Management (SISP) of UkrDO Radon – Kyiv Branch

The Kyiv Branch of SISP is used to store disused radioactive sources that had been applied in medical treatments, industrial uses, and scientific research.

26 February, 2022: News organisations reported that this facility was struck by a bomb or missile; however it is now confirmed that the facility has not been damaged and operation of the its automatic monitoring system has been restored. There are no reports of radiological releases.