There actually have been many months without more than half of nuclear reactors in France in 2022 - beginning 2023. And in France there are not enough different energy sources to compensate.
Taking down such reactors is a periodically routine for maintenance. The question is only how fast you can bring them up again (especially in case of serious repair needs).
> But your point about French NPs is technicality which can be rectified.
No, you cannot avoid using electricity few months in summer to have electricity for the rest time. And you cannot double the number of extremely costly NPs to have one half online while another half is being maintained/repaired.
