How exactly would you use a nuclear reactor in space to melt stuff? I assume it would be indirectly right?

On earth, the nuclear reactors are radioactive rods that heats up water, to create steam, to spin a turbine, to create electricity. This is like a 5 stage process to indirectly generate electricity. But all the intermediary products are now radioactive.

So in space, I assume you can use the same steps to generate electricity, and then use the electricity to run a furnace, to heat up the minerals to melt it into pure metals.

Or is there some other process of using the nuclear radiation directly in space?