The visit by the International Atomic Energy Agency’s director general follows allegations from Russian President Vladimir Putin and other officials that Ukraine has tried — or intends to try — to attack the plant amid the ongoing Ukrainian incursion in the area. Kyiv has denied the allegations.

But in a war that has seen Putin’s own troops invade and capture nuclear facilities in Ukraine, a possible attack on the Kursk plant would be in keeping with tactics Moscow has established.

Grossi said his tour enabled him to “look at the most important parts” of the plant, which is less than 50 kilometers from fighting between Russian and Ukrainian forces.

“A nuclear power plant of this type so close to a point of contact or military front is an extremely serious fact,” he said, as quoted by Reuters. “The fact we have military activity a few kilometers, a few miles away from here, make it an immediate point of attention.”

Grossi also highlighted what is a particular vulnerability of the Kursk plant, which runs four Soviet graphite-moderated RBMK-1000 reactors—the same design as those at the Chernobyl nuclear plant that in 1986, when Ukraine was part of the Soviet Union, became the scene of the world’s worst nuclear disaster.

“The peculiarity of the Kursk NPP is that RBMK type reactors operate there. Due to their construction RBMKs have no protective layer or container many reactors of other types worldwide are equipped with,” Grossi told reporters at a press conference following his visit to the plant.

“The core of the reactor containing nuclear material is protected just by a normal roof,” he added. “This makes it extremely exposed and fragile, for example, to an artillery impact or a drone or a missile.”

Ukraine launched its surprise incursion into Kursk on Aug. 6 and has said it is making advances, even as Russian forces move deeper into eastern Ukraine.

“I was informed about the impact of drones, I was shown some of the remnants of those, signs of impact they had,” Grossi said on Tuesday.

Grossi, who noted the Kursk power plant was “operating in a very close to normal conditions,” emphasized that it was “important to talk” and “keep dialogue.”

“At the end of the day, again, this may sound common sense and simple: Don’t attack a nuclear power plant,” Grossi told reporters, adding that he was in “close contact” with Russian authorities and would visit Kyiv next week to talk to Ukrainian President Volodymyr Zelensky.

The International Atomic Energy Agency has repeatedly warned of the dangers of fighting around nuclear plants following Russia’s full-scale invasion of Ukraine in February 2022.

During the first days of the war, Russian forces seized the Zaporizhzhia nuclear plant in southern Ukraine, and likewise briefly held the still highly radioactive zone of the decommissioned Chernobyl plant in the north. Bellona has published reports outlining the dangers of these incursions by Russian forces, as well as the complicity of Rosatom, Russia’s putatively civilian state nuclear corporation, in the ongoing hostilities.

By stationing heavy military equipment within the confines of the Zaporizhzhia facility — which is the largest nuclear plant in Europe—Moscow’s troops have all but guaranteed that its six VVER type reactors would be drawn into the conflict. Russian troops have also reportedly tortured Ukrainian technicians and forced them to sign work contracts with Rosenergoatom, Rosatom’s plant operations division.  

Moscow has even floated the disquieting notion of restarting the plant’s reactors—something that would make any possible accidents or strikes at the plant immeasurably worse as dangerous radionuclides would reform in the reactor’s cores.  

Unlike the reactors at the Kursk plant, however, Zaporizhzhia’s more modern VVER-style reactors are fitted with containment structures that are designed to withstand even the impact of a crashing airplane, somewhat heightening their durability on an active front of war.

While the strategic aims of Ukraine’s Kursk incursion remain uncertain, President Volodymyr Zelenskyy on Thursday said the attack is part of an effort to bring the war to an end on terms amenable to Ukraine.

The Kursk plant’s Unit 1 reactor, which dates from 1976, was shut down in 2021 to operate in non-generation mode. Unit 2, which dates from 1979, was shut down in 2024. Reactor Number 3, from 1983, and Reactor Number 4, from 1985. Earlier this week, the Number 4 was taken out of service for planned repairs, leaving Number 3 as the single active unit.

Construction of Kursk-2—essentially new reactors of the VVER-TOI type—was begun in 2018. The two reactors are not yet operational.