It is not about blackouts but about the risk induced by a nuclear plant in a warzone.
That's what International Atomic Energy Agency's (UN agency in charge of civilian nuclear) boss said about it: "Director General Grossi reiterated his deep concern about the apparent increased use of drones near nuclear power plants since early this year, saying such weaponry posed a clear risk to nuclear safety and security"
"any military attack on a nuclear site – with or without drones – jeopardizes nuclear safety and must stop immediately"