> Didn't France very recently have to shut down or limit a bunch of reactors due to <checks notes> the river water being too warm.

Because of environmental limits to protect the river ecosystems, not because of any safety or operational constraints. Many of these limits were set years ago, when the water temperature in rivers was lower, and haven't been increased since - leading to very tight margins. When the grid is stretched, the plant operators usually get a temporary authorization to exceed the environmental limits.

Every year this is big news for some reason, even though it amounts to a roughly 0.3% reduction of yearly electricity generation. It only impacts river cooled plants, and only those that don't also have a cooling tower.