If you're only going to the asteroid belt, you can probably get away with photovoltaics instead of nuclear power, too. And yeah, it seems it would be better to

If you're only going to the asteroid belt, you can probably get away with photovoltaics instead of nuclear power, too. And yeah, it seems it would be better to do it in place. But if it's really quite pure metal, there's not much refining that would need to be done.