[asacrowflies]

It's generally bad and kills local eco system with algae blooms and messing up seasonal cycles of nutrients/food. But that's just with dumping the heat into environment especially in freshwater river based reactors and a pretty raw system of dumping hot water into the river ...

Clever use of physics and cooling towers allows us to mitigate the problem..release the energy slowly over time or use the thermal for something else.but costs a lot more than just dumping it into ocean and doing lazy misleading napkin math.