Update 339 – IAEA Director General Statement on Situation in Ukraine

The Ukrainian electrical grid was again the target of military activity, over the past weekend, leading to significant impacts to several regions of Ukraine and nuclear power plant (NPP) operations, stated International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi.

Power lines linking Ukraine with neighbouring countries were disconnected, triggering a cascade of power lines being disconnected within Ukraine. As a result, a unit at one NPP disconnected from the grid due to fluctuations and automatically shutdown. Other units at other NPPs were forced to reduce power. The Chornobyl site experienced a complete loss of off-site power and relied on its emergency diesel generators for approximately one hour.

"This latest grid event in Ukraine is a stark reminder of the ever-present risks to nuclear safety and security arising from deteriorating grid conditions. Extensive repairs are needed to improve the reliability of power supply to Ukrainian NPPs and to strengthen their resilience to further grid events," Director General Grossi said. "Once again, I call for maximum military restraint, as well as full observance of the Seven Indispensable Pillars to enable these essential repairs to take place."

Amid increased military activity impacting the Ukrainian electrical grid, three IAEA teams are visiting 10 substations critical to nuclear safety and security in Ukraine. The objective of this two-week IAEA mission is to assess the continuing damage to the grid, review repair efforts and identify practical steps to strengthen the resilience of off-site power supplies to the country's NPPs. One of the teams has also visited Kyiv, where they discussed further IAEA support to NPP operations under deteriorating grid conditions.

This is the second such mission in as many months; the previous mission took place in December 2025, which confirmed the effects of cumulative impacts on NPP operations and staff conditions.

Further evidence of decreasing grid stability within Ukraine was apparent at the Chornobyl NPP in late-January. The IAEA team was informed that the diesel generators for the site's New Safe Confinement and the Interim Spent Nuclear Fuel Dry Storage Facility unexpectedly started on Friday, 23 January, due to fluctuations from the grid. The diesel generators for both facilities were manually put in standby mode within minutes. "This further highlights the impact that military activity on the grid can have on safety systems," Director General Grossi added.

Earlier last week, Chornobyl NPP detected 44 drones within their surveillance zone. On Tuesday last week, the IAEA team at Rivne NPP sheltered at their hotel, while two drones were detected within the plant's surveillance zone. Another six drones were detected at Rivne NPP last week.

Over the past two weeks, IAEA teams at the Khmelnitsky and South Ukraine NPPs safely rotated.