Materials used for their nuclear properties
Materials for the nuclear industry

Uranium, in oxide form, is most commonly used as fuel, usually enriched in its fissile isotope ²³⁵U. Other uranium- or plutonium-based compounds (carbides or nitrides) could be considered, but comparison of the various physical and employment properties generally favor the choice of oxide. UO₂ was chosen because of its very high melting temperature (2,845°C), which guarantees large margins in accident situations, and for its inert nature towards water. On the other hand, its thermal conductivity is low, below 2 W · m^–1· K^–1 at 1,000°C.

As the ²³⁵U isotope content is relatively low in natural uranium (around 0.7%), it is necessary to enrich the fuel in this fissile isotope. Exploitation of deposits and concentration of ore...