International Atomic Energy Agency (IAEA) Director General Rafael Grossi arrives on the opening day of the agency's quarterly Board of Governors meeting at the IAEA headquarters in Vienna, Austria, November 20, 2024.

International Atomic Energy Agency (IAEA) chief Rafael Grossi said late on Monday that he was on his way to visit Kyiv and inspect a key substation that is critical for the safety of Ukraine's nuclear power.

"On my 11th visit to Ukraine since the war began," Grossi wrote on X. "I'm heading to Kyivska substation, critical for the safety of Ukraine's nuclear power, to assess damage and help prevent a nuclear accident."

Last week, the IAEA said in a statement that Grossi would visit Kyiv for "high-level" meetings to ensure nuclear safety in the war that Russia started in February 2022.

In September, Ukraine and the IAEA agreed that the agency's experts would monitor the situation at key Ukrainian substations in addition to monitoring nuclear plants.

More than half of the electricity consumed in Ukraine is generated by three nuclear power plants, but Russian missile and drone attacks on substations threaten the stable operation of nuclear power plants, according to Ukraine's nuclear inspector's office.

The Kyivska substation allows for the transfer of excess capacity from Ukraine's west to central regions thanks to the hundreds of kilometres long (miles long) Rivne-Kyiv transmission line, helping with power supply to Kyiv and the surrounding region.

"An increasingly fragile grid poses a growing risk to all NPPs (nuclear power plants)," Grossi said in his post on X.