Natural uranium is pretty unremarkable. The greatest danger from it is heavy metal poisoning. It's also common enough that restricting its availability would be rather difficult.
Strictly speaking, if you got enough of it and were sufficiently determined you could create an improvised nuclear reactor with it, something along the lines of a carbon-moderated design. But the risk from that would be fairly minimal apart from some local radioactive contamination.
It's just the ore. Not purified, and not enriched for a specific isotope. So its radioactivity is vastly less, and it's really just a novelty and for playing with your geiger counter.
