International Atomic Energy Agency (IAEA) experts have so far found no visible indications of mines or other explosives currently planted at Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP), but they still need additional access to carry out further such checks at the site, Director General Rafael Mariano Grossi said today.
The team of IAEA experts were today able to inspect parts of the plant’s cooling system, including some sections of the perimeter of the large cooling pond and the isolation gate of the discharge channel of the nearby Zaporizhzhya Thermal Power Plant (ZTPP). Both this channel and the cooling pond hold reserves of water that remain available for use by the ZNPP despite the destruction of the downstream Kakhovka dam more than three weeks ago.
The IAEA experts have also been conducting regular walkdowns across the six reactor units and other areas around the site. Access to further areas is still expected, including parts of the turbine halls and some parts of the cooling system.
As previously indicated, the IAEA is aware of reports that mines and other explosives have been placed in and around the ZNPP, including mines near the cooling pond.
“We take all such reports very seriously and I have instructed our experts at the site to look into this matter and request the access they need for doing their job. Until now they have not observed any mines or other explosives. Further access will still be needed,” Director General Grossi said.
As Director General Grossi said last week, no mines were observed at the site during his visit to the ZNPP on 15 June, his third in less than ten months. However, the IAEA has been aware of a previous placement of mines outside the plant perimeter, which the Agency has reported about earlier, and also at particular places inside.
The five basic principles for the protection of Europe’s largest nuclear power plant (NPP) that Director General Grossi established on 30 May at the United Nations Security Council state that there should be no attack from or against the plant and that it should not be used as storage or a base for heavy weapons – multiple rocket launchers, artillery systems and munitions, and tanks.
“We need full access to be able to confirm that the five principles have not been violated, and we will continue to request the necessary access to all those areas essential to nuclear safety and security so that we can deliver on this mandate, including that the plant should not be used as storage or base for heavy weapons and munitions,” Director General Grossi said, adding that the IAEA team had not reported any shelling or explosions over the past week and that the military presence at the site appears unchanged.
“We are reinforcing our own presence at the plant to monitor compliance with these principles that are of paramount importance for protecting the plant and preventing a major nuclear accident during the war,” he said.
Since the Kakhovka dam was breached on 6 June, causing a rapid drop in the reservoir’s level, the ZNPP has been relying on separate reserves of water held near or at the site, especially the ZTPP’s discharge channel.
Currently, the plant’s six reactors continue to be cooled using the essential cooling system, now being replenished with underground water pumped from the site’s drainage system, Director General Grossi said. For the site’s other water needs, the plant has recently switched from using the ZTPP discharge channel to the large cooling pond next to the site.
As a result, the height of the ZNPP cooling pond is declining by up to 1 centimetre per day due to site usage and evaporation, but water from the drainage system is also being used to replenish this body of water, thereby slowing the reduction rate in the water level. The pond’s current water level is just over 16.5 metres.
On 23 June, as indicated in the Director General’s Update 167, the ZNPP started the normal circulation pumps to take water from the ZTPP’s inlet channel – which used to be directly connected to the reservoir but has since been detached from it – into the same facility’s discharge channel but soon had to stop because the water level was too low for operating these pumps. It was the first such attempt since 8 June.
Instead, Director General Grossi said, the plant is preparing to use smaller submersible pumps to access water from this inlet channel and refill the ZTPP discharge channel, whose level had been falling by around 10 centimetres per day until the plant started using the cooling pond. Its height has now stabilized at just under 17 metres, helped also by recent rain and cooler weather.
Pumping additional water into the discharge channel would provide an extra buffer for the ZNPP, whose six reactors are all in shutdown but still need both power and cooling water.
To help preserve these existing but still finite resources the plant has also reduced consumption of water that is not necessary for essential nuclear safety and security functions as much as possible.
“Even though the site currently has sufficient water reserves for some months, the plant needs to act already now to ensure sufficient water for the longer term. The plant is working to address this issue, but it is a complex undertaking, which we witnessed once again last week,” he said.
The ZNPP remains dependent on a single operational 750 kilovolt (kV) external power line for the electricity it needs for cooling the reactors and other essential nuclear safety and security functions, compared with four lines before the armed conflict in Ukraine. If this line were to fail again – as has happened repeatedly in recent months – the site currently only has emergency diesel generators available for the electricity it needs to pump the water that cools the reactors and spent fuel ponds.
Five of the ZNPP’s six reactors are in cold shutdown. Unit 5 remains in hot shutdown to generate steam required for the site. The IAEA experts visited the Unit 5 main control room yesterday and confirmed the hot shutdown status. The experts have also been informed that the plant is still assessing the need for steam to determine what type of external steam generator could be installed and possibly allow the cold shutdown of Unit 5. The IAEA is also aware that the Ukraine regulator has made changes to the licences of some of the units of ZNPP, including that the operation of Unit 5 be carried out in a cold shutdown state.
The IAEA also has teams of experts permanently present at Ukraine’s other NPPs to assist in efforts to maintain nuclear safety and security during the conflict.
On 13 June, a delivery of spare parts for the emergency diesel generators of the South Ukraine NPP took place. These spare parts are essential for the maintenance and functionality of the emergency diesel generators, so their proper functioning is ensured to prevent a nuclear accident due to loss of off-site power. The delivery followed the arrangements agreed on 5 May between the IAEA, France and Ukraine’s Energoatom. Additional spare parts foreseen under this agreement will be delivered soon.
Yesterday, the IAEA coordinated its 19th equipment delivery during the conflict, consisting of five decontamination units for Ukraine’s State Emergency Services, procured with support from the European Union. Five additional units have been procured with other funds and are awaiting shipment to Ukraine.