I encourage you - and anyone - to read the excellent book:

_The Making of the Atomic Bomb_ [1]

... and, in this case, to pay special attention to the multiple chapters describing in painful detail just what is involved in refining and extracting Uranium. As in, cubic acres of land mechanically and chemically processed to extract ounces of material ... which is then sent to enormous production facilities, at tremendous cost, only to begin the refinement process.

It is an incredibly long, dirty and energy intensive journey and I am not sure if the ledger of carbon expenses properly accounts for these steps.

[1] https://en.wikipedia.org/wiki/The_Making_of_the_Atomic_Bomb