POLYCRYSTALLINE EFFECTS ON IRRADIATION CREEP AND GROWTH IN TEXTURED ZIRCONIUM

Analytic expressions based on a self-consistent deformation model are derived to relate irradiation deformation of a polycrystal to that of a single crystal, in terms of the specimen crystallographic texture, for low and high neutron-fluence regimes. By interpolating between these two extreme regimes, an approximation for intermediate fluences is also derived. This calculation concludes that irradiation creep and growth are additive, but that the steady-state growth rate depends on creep compliance. The steady-state growth rate and creep compliance cannot be obtained by simply averaging over grain orientations.