Eli5: how do cooling towers for power plants work?

Question

Plus if these plants are next to a body of water why would they need to cool down their water if they can use the water form that source?

In: 2

Answer 1

The reactor gets hot, they need water to cool down the reactor, but use the heat from the water cooling down the reactor to create steam, using that steam to spin generators, creating electricity. They need constant cool water (which they get from lakes and oceans) to cool down the reactor so the water doesn’t getting too hot.

Imagine cooking in a pressure cooker. You need heat, but you also don’t want it to get too hot that it might explode. (side note: reactors such as in the US can’t explode like Chernobyl, but that’s another different type of science)