A critical study of the ring expansion test on zircaloy cladding tubes

The canning of fuel elements in nuclear reactors is subjected to stress and strains, which may cause failure if the material does not possess sufficient ductility. Of particular interest is localized strain in the circumferential or transverse ductility. The ring expansion test has been used for the determination of what has been called the transverse ductility of fuel element cladding. However, after some thought, it is realized that the ductility determined in this test does not really represent the determination in a fuel pin. In this paper some results, which serve to illustrate the limits of the test to rank materials, have been discussed.