Update 344 – IAEA Director General Statement on Situation in Ukraine

Zaporizhzhya Nuclear Power Plant (ZNPP) relied solely on its recently repaired backup power line for several hours earlier this month, following scheduled maintenance that required the intentional disconnection of its main power line for several hours. The backup power line had only just been restored the previous day, further emphasizing the continued fragility of nuclear safety conditions amid the conflict, IAEA Director General Rafael Mariano Grossi said today.

According to the IAEA team based at the ZNPP, the plant's main power connection was temporarily suspended on 6 March to perform essential maintenance work. During this period, the 330 kV Ferosplavna-1 backup line - successfully restored on 5 March 2026 under a fifth local ceasefire negotiated by the IAEA - maintained a stable supply of off-site power to the ZNPP.

"The ZNPP's fragility in the face of limited off-site power options is putting constraints on electrical maintenance. It is another indication of the critical importance of robust, diverse and dependable off-site power infrastructure to ensure nuclear safety and security at the ZNPP," Director General Grossi said.

Separately, during the past two weeks, the IAEA team at the ZNPP held a meeting regarding the plant's updated organizational structure introduced in 2025. They discussed the updated reporting lines, responsibilities and the departments that were merged.

The team also observed the testing of an emergency diesel generator (EDG) at Unit 3. EDGs provide essential backup power support in case a nuclear power plant (NPP) was to lose access to all off-site electricity, something which has happened twelve times at the ZNPP since the start of the conflict. The team also engaged in discussions focusing on the 2026 maintenance plan and fire protection systems and observed a partial evacuation drill involving personnel in the administrative building.

The State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) informed the IAEA that during the night of 11-12 March, attacks targeting and destroying an electrical substation close to the subcritical Neutron Source Installation at the Kharkiv Institute of Physics and Technology (KIPT) resulted in its disconnection from the electrical grid until 13 March. During this outage, the facility relied on EDGs.

Elsewhere in Ukraine, the IAEA team at the Chornobyl NPP reported that on 14 March, the site was disconnected from its 750 kV Kyivska transmission line for nearly 24 hours. The SNRIU informed the IAEA that the cause of the disconnection was an attack targeting an electrical substation essential to nuclear safety and security. Although off-site power to the plant was not lost, this disconnection and subsequent fluctuations in the electrical grid automatically activated the EDGs supplying the New Safe Confinement and Interim Spent Fuel Storage Facility 1. The generators were manually switched off after 15 minutes.

"These episodes underscore how grid instability and the vulnerability of off-site power is affecting nuclear safety and security at Ukraine's nuclear facilities," Director General Grossi said.

Additionally, the IAEA team at the South Ukraine NPP reported that a drone was detected one kilometre from the site on 18 March, following sightings of two drones, detected approximately five kilometres from the site during the night of 6 to 7 March 2026.

Over the past two weeks, the Agency has continued with deliveries under its comprehensive programme of assistance to Ukraine in nuclear safety and security. Helmets and body armour have been delivered to the KIPT National Science Center, enhancing personal protection measures at the site. Beds and mattresses were provided to the Chornobyl NPP to improve staff living conditions under the medical assistance initiative. A high precision electrometer for radiation dosimetry was delivered to the National Scientific Center "Institute of Metrology" and telemechanic cabinets were delivered to the Joint Stock Company "Mykolaivoblenergo".

Within the framework of the IAEA Support and Assistance Mission to the Kherson Oblast (ISAMKO), advanced IT and laboratory equipment was provided to the Odesa Regional State Laboratory and two state-of-the-art gas chromatographs have been supplied to the Vinnytsia Regional State Laboratory and the Ternopil Regional State Laboratory.

The deliveries were supported with funding from Italy, Japan, Norway, and the United Kingdom.