Nuclear safety remains precarious at the Zaporizhia NPP (ZNPP) and its six reactors cannot be restarted as long as the military conflict continues to endanger the situation at the site, International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi told the regular June meeting of the IAEA Board of Governors.
He highlighted “the extremely vulnerable” status of the off-site power supply at the site, which for more than a month now has relied on one single power line for the electricity it needs to cool its reactors and spent fuel. Before the conflict, Europe’s largest NPP had access to 10 power lines. Grossi also noted that the ZNPP’s “reliance on groundwater for cooling remains an interim solution, whilst in their cold shutdown state”. The plant has depended on 11 groundwater wells since the downstream Kakhovka dam was destroyed in June 2023.
ZNPP has informed the IAEA about a planned project to pump water into the cooling pond from the Dnipro River in order to maintain a water level sufficient to cool one operating reactor initially, followed by a second unit, until the pond reaches its full capacity. According to the site, a pumping station will be constructed to supply water directly to the cooling pond until the plant can rebuild the Kakhovka dam. The exact location of the pumping station cannot yet be determined, as it depends on security conditions, ZNPP said, stressing that the project would only start once military activities cease.
The IAEA team based at ZNPP has held several meetings with the ZNPP management to discuss the site’s electrical system and also visited its 750 kilovolt (kV) switchyard. Apart from the sole remaining 330 kV back-up line that was disconnected due to military activities on 7 May, the site does not know the current condition of its five other 330 kV lines, which remain unavailable after they were damaged outside of the ZNPP area early in the conflict.
The ZNPP said maintenance work was conducted at one of the four 750 kV power lines that was originally connected to ZNPP before being damaged in 2022. Since the conflict, the ZNPP had lost access to three of its 750 kV lines.
The IAEA team has been informed that the Russian regulator, Rostekhnadzor, over the next two weeks will perform pre-licensing inspection activities at ZNPP reactor 1&2, whose current operational licences issued by Ukraine are due to expire in December this year and February 2026, respectively. The IAEA team has asked to observe these activities and will seek additional information regarding items such as the scope of these undertakings and any criteria for assessing nuclear safety.
Over the past several weeks, the IAEA team has also been monitoring a leak in one reactor unit’s essential service water system which delivers cooling water to the safety systems. The leak – which can occur in NPPs without any significant safety consequences – was discovered during maintenance and the team was informed that it was caused by corrosion. It has since been repaired.
The IAEA team reported hearing military activities on most days over the past weeks, at varying distances from ZNPP, including the recently reported drone attack on the site’s training centre.
