Texture Analysis in Zircaloy Cladding Tube Material for Nuclear Fuel

Zirconium-based alloys are used commonly world-wide in the manufacuring of cladding tubes for fuel elements in light-water nuclear reactors. The pilger mill plant at the AEC in South Africa has been producing Zircaloy-4 cladding tubes for the Koeberg pressurized water reactors (PWRs) near Cape Town since the mid-1980s. The specific thermomechanical history of a cladding tube determines the final texture which makes it possible to tailor the texture according to service requirements. The range of pole figures obtained from different production stages at the AEC plant is presented. Tube sample preparation was reduced to a single surface etch. Prism plane pole figures yielded information about grain behaviour during thermomechanical processes. The pole figure data are used to calculate several different texture parameters which serve to characterize the texture quantitatively and for comparison with other manufacturers.