The front end of the fuel cycle includes all the steps needed to produce fuel ready for loading into a reactor:
- Mining — Extracting uranium ore from the ground (open-pit, underground, or in-situ leaching).
- Milling — Crushing and chemically processing the ore to produce yellowcake (a uranium oxide concentrate, U₃O₈).
- Conversion (Purification) — Converting yellowcake into uranium hexafluoride (UF₆), known as “hex”, which is suitable for enrichment.
- Enrichment — Increasing the proportion of the fissile isotope U-235 from its natural level of 0.711% to the level required for the reactor (typically 3—5% for a PWR).
- Fuel Fabrication — Converting enriched UF₆ into uranium dioxide (UO₂) ceramic pellets, loading them into metal tubes (cladding) to form fuel rods, and assembling the rods into fuel assemblies ready for the reactor.