It also comes in a form called yellowcake. :D

It looks like you've got some radium or tritium mixed in there.

Like 50% radium or tritium (or both).

That's the only way it could glow fluorescent green like that. Well, if you put glowstick chemicals in there I guess that would be another reason for it to glow like that.

Here's a picture of some real uranium-235, which is what modern PWRs use as fuel: https://en.wikipedia.org/wiki/File:HEUraniumC.jpg

Oh right, and I forgot to mention that uranium by itself wouldn't cause any mutations! It barely gives off radiation at all! Uranium-235 has a half-life of 703 million years. Uranium-238, 5 billion years. Uranium-232 (which doesn't exist in nature) DOES have an eight minute half-life AND gives off alpha and gamma radiation, but there is absolutely ZERO chance that 1. someone would get access to it and 2. it would exist in such low concentrations to ONLY give off mutations. Most of the time U-232 just kills you, even with the tiny little bit made in regular operation. The reason nuclear is safe even with that is that nuclear reactors are so well shielded that it's not a problem inside the building, let alone outside. Yeah, I'm like a fun Gestapo in here. The thing is that I understand radiation and nuclear chemistry more than most laymen (and that's only because I'm a ninth grader) and I have a thing where I get annoyed with inaccuracy.