Nuclear power plants only really have an effect on the water temperature if they do not have a cooling tower. This makes the plant considerably cheaper, but, as you mentioned, damages the ecosystem.
Only in rare cases, such as during revisions or emergencies, they might be unable to cool the condenser using the tower-coolant-loop. Then they might have to warm up the water temporarily.
> you definitely don't want to have a nuke potentially discharging contaminated water near population centres (in case something goes wrong and the discharge needs to happen).
There is no such failure case that a "discharge needs to happen" for the irradiated water. There is a comparatively tiny amount of deionized and supercleaned water in the reactor that is always cycled around. Even if such a case were to occur (how??), the amount of water would be easy to handle/store.
Only in rare cases, such as during revisions or emergencies, they might be unable to cool the condenser using the tower-coolant-loop. Then they might have to warm up the water temporarily.
> you definitely don't want to have a nuke potentially discharging contaminated water near population centres (in case something goes wrong and the discharge needs to happen).
There is no such failure case that a "discharge needs to happen" for the irradiated water. There is a comparatively tiny amount of deionized and supercleaned water in the reactor that is always cycled around. Even if such a case were to occur (how??), the amount of water would be easy to handle/store.