At that, he's freaking lucky it's already an oxide. If he had pure powdered uranium of any isotope, it would burn. In fact, finely divided uranium metal is pyrophoric- doesn't even need a heat source. I worked on a plasma isotope separation project right out of the university, and we had to have particle masks with HEPA filters at the ready when the module was opened. We had liquid nitrogen for the superconducting magnets, and there was usually a Dewar of it near to hand to toss onto the fire. Cooled it and suffocated it at the same time.
If you get to thinking you’re a person of some influence, try ordering somebody else’s dog around.