Many people do not use uranium in azure bombs, or regular bombs, but the real reality is: Uranium is OP. Uranium creates massive tempretures (exponentally) under massive pressure, so that means that uranium can be used as a heat generator for your azure bombs, or nuclear bombs. Example:

, you can see that I use massive amounts of uranium, and there's a massive neutron + proton burst. If you put warp into this, then you've got a pretty powerful azure bomb. That's why Uranium is OP.