The nuclear fuel cycle encompasses every stage of nuclear fuel from cradle to grave. The "front end" includes uranium mining and milling, conversion to uranium hexafluoride gas, isotopic enrichment to increase the concentration of fissile U-235, and fabrication into fuel assemblies. The fuel then undergoes fission in a reactor (the "service" period), after which the "back end" involves either direct disposal of spent fuel (the open or once-through cycle) or reprocessing to recover usable materials for recycling (the closed cycle).
Most countries today operate on an open fuel cycle — spent fuel is stored and eventually destined for geological disposal. France is the notable exception, reprocessing spent fuel at its La Hague facility to extract plutonium and uranium for reuse as mixed-oxide (MOX) fuel. The choice between open and closed cycles has profound implications for waste management, resource sustainability, and proliferation risk. Advanced fast reactors could enable a fully closed fuel cycle, dramatically reducing the volume and longevity of radioactive waste.
The fuel cycle is receiving renewed attention as advanced reactors and SMRs create new fuel requirements. HALEU production must scale massively. TRISO fuel fabrication is being industrialized. Companies like Centrus Energy, BWXT, and Framatome are investing in new fuel manufacturing capabilities. The fuel cycle also intersects with national security — enrichment technology is dual-use, and fuel supply chains have geopolitical dimensions that were starkly highlighted by the push to reduce dependence on Russian nuclear fuel services. For deeper coverage, see DeepTechIntel's nuclear section.