Biaxial creep behavior of textured zircaloy tubing

Abstract

Zirconium alloys are commonly used in light-water reactors as thin-walled tubing to clad highly radioactive fuel. The tubes experience varied stresses at high temperatures while being exposed to high-neutron radiation, resulting in thermal creep and radiation growth and creep. However, the dimensional stability of these materials is important to preventing leakage of fission gases and contamination of the coolant water. Predicting the dimensional changes of the thin-walled tubes is further complicated by the anisotropic nature of the hexagonal close-packed metals. This article summarizes the procedures used in the texture analyses and crystal plasticity in developing model equations to predict the dimensional changes of Zircaloy fuel cladding, both out-of-pile and in-reactor. These methodologies can be extended to the life prediction of these important structures in nuclear reactors.