IAEA reports communications blackout at Zaporizhzhia nuclear power plant

The Zaporizhzhia Nuclear Power Plant experienced a prolonged communications blackout this week amid reports of increased military activity nearby, International Atomic Energy Agency Director General Rafael Mariano Grossi said May 28.

The plant lost both landline and internet connections for about 12 hours on May 27, marking the longest such outage at the facility since the start of Russia's full-scale invasion of Ukraine, according to the IAEA.

The cause of the outage was not immediately clear, but it coincided with reported attacks on the nearby Russian-occupied city of Enerhodar, where most plant employees live.

"For many hours, we were unable to contact our team of experts at the site, and the plant was unable to communicate with the outside world in the usual way," Grossi said.

"This was clearly a very concerning event in terms of nuclear safety and security. The IAEA team will continue to investigate what caused this communication blackout and discuss how to prevent a recurrence," he added.

The communications outage violated one of the seven core principles for maintaining war-time nuclear safety established by Grossi and the IAEA, which states that nuclear facilities must maintain reliable communication with regulators and outside authorities.

The IAEA said earlier this month that it had observed a significant increase in drone activity near several Ukrainian nuclear power plants. While agency teams reported no direct damage to the facilities, they warned that the activity posed "significant risks to nuclear safety and security."

The Zaporizhzhia NPP is Europe's largest nuclear power plant and among the 10 largest in the world. It has been under Russian military occupation since 2022, along with large swathes of Zaporizhzhia Oblast. The regional capital and most of region's population remain under Ukrainian administration.