Im not sure uranium or other radiological material is really rare enough to call it non-renewable. Technically it isn't, but technically the sun doesn't last forever either. Nuclear materials can be found basically everywhere with rock or dirt, and much of it is recyclable into other nuclear materials down to the tiniest little bits. Just because we currently only want the richest and cheapest and least power intensive mines doesn't mean that is all we have available. It is like worrying about running out of iron, technically yes but realistically no.