Purex process which utilizes solvent extraction to separate and purify uranium and plutonium from each other and from fission products contained in irradiated uranium fuel elements.

Limitations on the service life of a fuel element imposed by degradation of the fissile core during irradiation have been a matter of great concern. Limitations imposed by changes in cladding properties during irradiation should be evaluated with equal care. Zircaloy-2, stainless steel, and aluminum alloys have been irradiated in the form of cladding on metallic and ceramic fuel elements. Several aspects of fuel behavior as influenced by these clad materials will be discussed. All observations related to irradiation behavior in this paper have been made on fuel specimens irradiated in water coolant.