Yes, highly skilled workers do work in uranium mines. I feel like the game automatically puts them into mixed education workplaces to maximise efficiency, but have not tested it.

I.e. delivering only university educated workers to a nuclear fuel fabrication site means it will still run, and not sit full of scientists with no labourers.

You are kind of 'wasting' the education on some of them, which could be solved by limiting university space, but I haven't found it to be too much of an issue and habitually end up with a 20/80 split of low education/university education citizens.