Fission reactors are not very useful targets in war. In Ukraine, their fleet of nuclear reactors are what's keeping the electricity grid running. And they are building new ones. In war time.
Because presumably France for instance would likely view someone blowing up one of their plants the same way as a nuclear attack. Given their nuclear deterrence policies that would end up badly for both sides
Germany doesn't have a nuclear deterrence and in the event of a nuclear war still might want to avoid having particular bad targets. I'd rather put any new money for nuclear into fusion instead of building large fission reactors.
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"
But why take the risk of fission reactors becoming targets in a war?