During the Russian missile and drone attack on Thursday morning, the Khmelnytsky, Rivne and Pivdennoukrainsk NPPs preventively reduced their capacity, and one of the Rivne NPP power units was disconnected from the grid, said Rafael Grossi, Director General of the International Atomic Energy Agency (IAEA).

"For a second time in less than two weeks, the Khmelnytsky, Rivne and South Ukraine NPPs lowered their power levels as a precautionary step during widespread military activities in the country... The operating NPPs have a total of nine reactors, all of which decreased output. One reactor, at the Rivne NPP, was also disconnected from the grid," Director General Grossi said.

The NPPs continued to receive external electricity, even though the Khmelnytsky site lost the connection to two of its power lines.

Two of the IAEA teams deployed in Ukraine were forced to seek shelter, the report notes.

There were no reports of direct damage to the NPPs, but the IAEA was informed by Ukraine that the strikes once again impacted the electrical substations which the plants use both to transmit and receive off-site power.

"These substations, identified by the IAEA as important for nuclear safety and security, have been damaged in previous attacks, including in August," the agency noted.

NPPs need reliable connections to the grid both to distribute the electricity they produce and to obtain off-site power for reactor cooling, the IAEA noted.

As reported, with the start of another massive Russian attack in Ukraine, emergency power outages were introduced on Thursday morning, and subsequently the regions switched to hourly schedules, providing outages mainly for a maximum of 14 hours a day, depending on the region and the order.