Hydroelectric dams typically cause even more damage when they fail, but I rarely see people worrying about whether using them for power will lead to war-time issues. https://en.wikipedia.org/wiki/Dam_failure

Of course, the Geneva Convention bans attacking dams, just like it bans attacking nuclear power plants.

The pollution from burning coal has already killed more people than nuclear disasters conceivably could.

If we could use only wind and solar power to fully replace fossil fuels and hydro, that could be a reasonable argument...

But it seems unrealistic to get enough energy without using some higher-density sources of energy, whether that's hydro or nuclear or oil, and if we're picking based on which one causes the least death, even accounting for wars and failures, nuclear seems to be a head and shoulder above the rest.

The primary thing that seems to be driving using coal plants and not using nuclear is purely monetary cost: nuclear plants take a huge up-front investment, coal plants already exist, and wind/solar can be transitioned to gradually with less up-front cost. The talk about nuclear's "danger" to me seems, quite plausibly, to be a post-facto justification based on not wanting to put up the money.