The French are getting 75% of their power from nuclear.
They also operate their plants differently. None of their plants operate at 100% capacity, maybe more like 75%. This is for a good reason - if a plant experiences an outage, whether planned (maintenance, refueling), or unplanned (happens very rarely), all the other plants take up the slack. They already have “spinning reserve” as part of their normal operation.
They also do their fuel cycle much differently than here in the United States. All spent fuel is reprocessed. Fission fractions are chemically stabilized by vitrification and sequestered in a geologically stable formation, and any unused fissile goes into new fuel rods. I have had professional experience with the former on the DOE West Valley Demonstration Project. Much of the French technology was used.
They also use a well proven PWR design based on a Westinghouse design.
France made the strategic decision to go with nuclear in order to be less dependent on Middle East petroleum, the supply being subject to the region’s political volatility. You can knock the French, but they did this right.
Ever driven thru much of rural France and Germany?
France is much more picturesque without the windmills.
Germany has windmills littered all over the countryside.