>Nuclear power and coal power are both heat engines turning heat into mechanical energy and subsequently electricity. They merely use a different heat source.

Not completely true. There are some experimental nuclear reactors that convert nuclear energy directly to electricity without the heat cycle, such as [Helion](https://en.wikipedia.org/wiki/Helion_Energy).

When presenting working experimental nuclear reactors Helion is not the company that I would use as my example. They are borderline scammy and given their lack of progress they seem to be stuck in the moving the goalposts phase for a long long time now. I wouldn't bet on them ever completing a working reactor that produces net power.

Maybe, but my point is that it does seem to be possible to generate electricity directly from nuclear reactions, without going through a thermal cycle (making heat, creating steam, using that to turn a turbine). I think there's some other experimental process that promises to do this with fission.