No elevated radioactivity has been recorded, the IAEA said in a statement, adding that diesel generators are currently used to power critical functions, including cooling systems.
It is not clear who is behind the attack at the facility, which is Europe's largest nuclear power plant. It occurred on Wednesday evening and was aimed at a nearby transformer station.
Kyiv and Moscow have repeatedly accused each other of risking a disaster by attacking the nuclear power plant and its nearby area.
The power outage is the 19th since Russia's full-scale offensive war against Ukraine began in February 2022.
