“The conflict in Ukraine is about to enter its fifth year,” Grossi said. “It continues to pose the world’s greatest threat to nuclear security.”
IAEA teams remain deployed at all nuclear power plants affected by the conflict and publish regular updates on nuclear safety and security conditions.
The Board of Governors is the IAEA’s main decision-making body and brings together representatives from 35 countries to oversee nuclear safety and safeguards, and to guide the work of the UN nuclear watchdog. Its current members include, among others, Russia, the United States, the United Kingdom and France.
External Power Is a Critical Safety Lifeline
Mr. Grossi stressed that A central safety requirement is reliable external power. – the electricity that a plant receives from the national grid. Without it, nuclear facilities must rely on backup systems to perform cooling and other essential safety functions.
“There must be a secure supply of external power from the grid for all nuclear sites,” he said, pointing to the IAEA’s “Seven Pillars” guidance for nuclear security during armed conflict, where external power is pillar number four.
He also cited Principle 3 of the IAEA’s Five Principles for protecting the Zaporizhzhya Nuclear Power Plant (ZNPP), according to which “every effort should be made to ensure that external power remains available and safe at all times.”
Grossi said both sets of guidelines have broad international support, including from the parties directly involved, and that he has repeatedly called for their compliance, including in the U.N. Security Council.
Progress in Zaporizhzhya amid continued risks
He reported on recent developments at the ZNPP, where Europe’s largest plant was reconnected on January 19 to its last 330 kilovolt backup power line after repairs were carried out under a temporary ceasefire negotiated with its Ukrainian and Russian counterparts.
The line had been damaged and disconnected since January 2, apparently due to military activity.
Until reconnection, ZNPP relied on its last remaining 750 kilovolt main line to provide external power to the safety systems needed to cool its six shutdown reactors and spent fuel pools. IAEA teams are also monitoring the plant’s ability to manage winter conditions, including preventing water in cooling and spray ponds from freezing.
Beyond the plants themselves, Grossi warned that Ukraine’s electrical substations are also crucial to nuclear security. “Damaging them undermines nuclear security and must be avoided,” he said. An IAEA expert mission is now assessing 10 substations vital to nuclear security amid ongoing attacks on the country’s electrical infrastructure.
Other nuclear facilities are also affected
IAEA teams have also reported military activity near other nuclear facilities, including the Chernobyl site, where damage to a critical substation disrupted multiple power lines and forced a temporary reliance on emergency diesel generators. The affected lines have since been reconnected.
Grossi said the IAEA has shown how international institutions can help reduce risks and provide predictability in a volatile war. But, he added, technical measures have limits.
“The best way to ensure nuclear safety,” he said, “is put an end to this conflict.“