If the biggest externality is heated water in a subarctic climate, or nuclear waste that gets stored on-site indefinitely in casks and produces no notable leaks or accidents (like has been done in the US for a long time now), the externalities are way less than literally any other form of energy production. That includes Dams, solar power, geothermal, wind, you name it.

No, people aren’t pretending that. Heat pollution in water is a tiny local issue compared to global warming.

It’s like complaining that a wool blanket is itchy so it might be better to catch hypothermia and die.

What prevents heated waste water from being used for…heat? Surely Finland uses central heating plants that pump hot water throughout the city (or maybe that’s just a Chinese/Russian thing?). What makes waste heat water less suited to heating, higher entropy?

Combined Heat and Power in Finland is very common, much more so than in rest of Europe. 80% of the fossil fuel power plants output both electricity and heated water. Compared to (quick googling) 8% in the US and 11% in EU.

Fear of nuclear power. People don't want water heated by it in their homes. So it is not done. It's not a purely rational thing.

The plants are also located away from cities, so utilizing the waste heat for district heating is uneconomical.

I think it just not hot enough after electricity production. So temperature is not high enough after it passes through turbines. Specially due to distances involved.

> And heat-polluted waste waters?

That's hardly unique to nuclear plants; in particular, coal plants typically have lower thermal efficiency.