The environmental impact of nuclear power vs. fossil fuels or even renewables is just a negligible number no matter how you spin it.
I too am confused like the GP poster as to how otherwise intelligent people just break down into baseless fearmongering about imaginary disaster scenarios while ignoring that today's conventional energy industry is literally thousands of times worse.
If every single operational nuclear power plant had a meltdown incident after operating for 20 years, they'd still be orders of magnitude less damaging than what we're doing today. The environmental impact and safety numbers are just that far apart.
https://www.statista.com/statistics/494425/death-rate-worldw...