They are, but not all nuke plant feature cooling towers. The problem here is for those without: they use water as a cooling fluid, but then just pour it back in

They are, but not all nuke plant feature cooling towers. The problem here is for those without: they use water as a cooling fluid, but then just pour it back into the river instead of evaporating it. The advantage is that they don't consume/move the water, the inconvenient is that they can't spit out 40C water without hurting the river's ecosystem.