Syllabus Coverage: NFC2.1
All nuclear fuels must satisfy requirements based on operational, safety and economic criteria:
- Operational: The fuel must have enough nuclear reactivity (and thus few neutron-absorbing impurities). It must have sufficient thermal properties such as high melting points and good thermal conductivity. Mechanically, the fuel must allow for sufficient mass flow and have optimal heat transfer surface areas.
- Safety: Fuel assemblies should incorporate control mechanisms such as control rods and burnable poisons. All highly radioactive fission products produced during irradiation must be contained within the fuel.
- Economic: Fuels must offer cost competitiveness through longevity, high burn-up, reliability and ease of manufacture within tolerances.
There are three broad categories of nuclear fuel in common use:
- Metallic fuel (uranium metal, possibly alloyed)
- Ceramic fuel (uranium dioxide, UO)
- Mixed oxide fuel (MOX — a blend of UO and PuO)