A drone attack has damaged part of the Zarya substation, located 300 metres from the perimeter of the Zaporizhia NPP (ZNPP), the ZNPP press service reported. ZNPP said that the attack by Ukrainian Armed Forces on the substation, which is involved in providing power to the NPP’s infrastructure facilities, poses a potential threat to the safety of the plant. ZNPP employees have introduced a back-up scheme for powering the plant’s infrastructure and International Atomic Energy Agency (IAEA) inspectors based at the plant were informed of the attack, according to the ZNPP Telegram channel.

A video showing IAEA inspectors inspecting the substation was posted on the ZNPP Telegram channel. In the video, ZNPP Director Yuriy Chernichuk explains that, as a result of damage to one of the transformers, an oil leak occurred but there was no fire. “Experts were taken to the scene and all their questions were answered,” he noted. He added that ZNPP would ask IAEA Director General Rafael Gross “to once again draw the attention of the world community to the dangerous events that are taking place around our station for the whole world”.

The press service of Russia’s Unified Energy System confirmed in a statement that the drone had damaged a part of the substation located in the “immediate vicinity of the UES perimeter” and that a backup power supply scheme for the plant’s facilities had been introduced.

Earlier, Russia’s Permanent Representative to International Organisations in Vienna, Mikhail Ulyanov, said that up to 62 Ukrainian unmanned aerial vehicles are registered in the area of the ZNPP every day. In just four months, there had been 2,054 such flights.

Meanwhile the latest update on ZNPP from the IAEA, issued before the drone attack, noted that the IAEA team had continued to hear explosions at various distances, including several close to the site, but no damage to the plant was reported.

Separately, the team was informed by the ZNPP that two power lines supplying the nearby city of Energodar had been damaged by unspecified military activities, prompting the use of diesel generators to operate the pumping station for tap water – including to the ZNPP – as well as other “vital” facilities in the city. The lines were re-connected later and the event had no impact on nuclear safety and security at the ZNPP, which continued to receive off-site power from the last remaining 750 (kilovolt) kV and 330 kV power lines.

The IAEA team had also observed an emergency exercise conducted by the ZNPP. The simulated exercise scenario included a loss of coolant accident in the unit 1 reactor caused by a fictitious large earthquake, followed by a loss of all off-site power and the failure of all three of the unit’s emergency diesel generators. A secondary aspect of the exercise scenario simulated a fire in the ZNPP’s training centre and injuries to two personnel, which required an evacuation of the training centre and the response of the fire brigade and ambulance.

The IAEA team, observing the exercise from the temporary emergency centre and the training centre, reported that the ZNPP noted an appropriate response of participating staff as well as equipment reliability. The ZNPP also identified opportunities for improvement, including in the communication between the exercise players related to plant data about the accident and the reporting of personnel contamination monitoring.

The IAEA staff continued to conduct walkdowns across the site, including to the pumping station of the unit 5 reactor where they discussed the operational status of the pumps considering the decline in the water level of the ZNPP cooling pond, which has fallen 2.2 metres since the destruction of the Kakhovka dam in mid-2023. In the ZNPP’s current shutdown status, the cooling water provided by 11 wells dug after the dam was destroyed remains sufficient for nuclear safety and security.

Researched and written by Judith Perera