Update 266 – IAEA Director General Statement on Situation in Ukraine

Most of Ukraine's operating nuclear power reactors once again reduced their electricity output early this morning following renewed attacks on the country's energy infrastructure, further underlining persistent risks to nuclear safety during the military conflict, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said.

For the third time in less than a month, several units of the Khmelnytskyy, Rivne and South Ukraine nuclear power plants (NPPs) lowered their power levels during widespread military activities in the country, while air raid alarms sounded at the three sites, Director General Grossi said.

One of the IAEA teams deployed in Ukraine was forced to shelter and reported hearing explosive detonations at mid-distance. Additionally, the team at the South Ukraine NPP was informed that military objects were observed flying approximately 300 metres from the site.

"Our teams deployed in Ukraine have witnessed how the growing instability of Ukraine's power infrastructure, as a result of frequent military attacks in recent months, is impacting the ability to safely operate the country's nuclear power plants," Director General Grossi said.

Ukraine's operating NPPs have a total of nine reactors, of which five decreased output this morning following instructions from the operator of the national grid, including one unit that was temporarily disconnected from the grid. Two other units were already operating below nominal full capacity following military strikes on the Ukrainian energy infrastructure in late November.

Three of the affected units subsequently returned to nominal full capacity.

There were no reports of direct damage to the NPPs because of today's attacks and disruption to the electrical grid. While there were no reports of any additional power lines being disconnected, some lines remain disconnected following the previous attacks on 28 November.

NPPs need reliable connections to the grid both to transmit the electricity they produce and to receive off-site power for reactor cooling. The increasing fragility of the electrical infrastructure means that attacks can cause significant fluctuations in the grid, which can affect the availability of safety systems, reducing defence in depth and impacting the nuclear safety of the reactors. The availability and stability of off-site power continues to be one of the main challenges for nuclear safety and security throughout the armed conflict.