The short version
Uranium's chain is short in tonnage and long in regulation. Conversion and enrichment exist at only a handful of sites worldwide, and every step is subject to international safeguards.
Stage by stage
Unconformity or sandstone-hosted uranium
The richest deposits sit where oxidised groundwater carrying dissolved uranium met reducing conditions and dropped its load.
Cigar Lake or in-situ recovery
High-grade ore is cut remotely through frozen ground; low-grade sandstone ore is dissolved in place and pumped to the surface.
Note: In-situ recovery moves no rock at all.
Conversion and enrichment
U3O8 becomes uranium hexafluoride, then centrifuges raise uranium-235 from 0.7% to 3-5%.
Note: Enrichment needs fluorine — which comes from fluorspar.
Fuel assembly
Enriched uranium is pressed into ceramic pellets and sealed in zirconium alloy tubes.