High fluence irradiation growth in single crystal zirconium at 553 K

Cluster Dynamics modelling of irradiation growth of zirconium single crystals

“…The SIA and vacancy diffusion coefficient D i and D v were adjusted to get the best fit between the calculated growth curve for a-axis crystals and the experimental points taken from [18,19]. The result is shown in Fig.…”

“…The DAD effect will be taken into account. We will apply the model to the experimental results published by Rogerson [18] in 1987 (who continued the work by Carpenter et al [19] in 1980) on growth of Zr single crystals irradiated with neutrons at 553 K. Particular attention will devoted to the 'breakaway growth' effect.…”

“…[18,19] a It was assumed in the model that vacancy relaxation is anisotropic and is fully oriented along the c-axis as suggested in [29,30]. Nevertheless, even considering an isotropic vacancy relaxation, it is still possible to get a very good fit of the growth experimental data by re-adjusting the value of V rel v , D i and Dv to V rel v = 0.8, D i = 5.0 Â 10 À8 cm 2 s À1 and Dv = 6.0 Â 10 À18 cm 2 s À1 .…”

“…As mentioned before, we will focus here on zirconium Neutron irradiation (6.5 Â 10 17 nm À2 s À1 % 10 À7 dpa s À1 ). From Rogerson [18] and Carpenter et al [19].…”

“…Description of the experimental results concerning irradiation growth of zirconium single crystals [18,19] The experimental results exposed here are taken from references [18,19]: cylindrical specimens of annealed pure zirconium (127 mm long and 4.5 mm diameter) were irradiated at 553 K in fast neutrons fluxes of between 5.3 and 7.6 Â 10 17 nm À2 s À1 (DIDO reactor). This neutron flux was converted into a point defect production rate using the proportionality factor published in Ref.…”