Diffusion of deuterium in Zr–2.5Nb alloy under neutron irradiation

Evaluation of variables affecting crack propagation by Delayed Hydride Cracking in Zr–2.5Nb with different heat treatments

“…The only hydrogen diffusion coefficient for irradiated Zr-2.5Nb found in the literature [44] does not differ from those measured in unirradiated materials. It is known that irradiation affects the Nb percentage in b phase [15], reaching a limit of about 32%Nb (nearly 50% of the initial value) after a fluence of 5 Â 10 25 n/m 2 .…”

“…Besides, the hydrogen diffusion coefficient change with Nb percentage of b phase when the material is heat treated. In the work of Khatamian [44] the dose received by the specimens was about 2 Â 10 24 n/m 2 which scarcely would produce changes in Nb concentration of b phase lower than 10% (Fig. 11 in [15]), this could explain why no differences were detected in [44] for hydrogen diffusion of irradiated and unirradiated specimens.…”

Formation and characterization of hydride blisters in Zircaloy-4 cladding tubes

“…Nevertheless, the variability of the material parameters concerning the hydrogen diffusion and solubility limit is high from one study to the other. For instance, more than 50% variability in the diffusion coefficient has been reported (comparison of data in [34,35,51,52,53,54,55,56,57,58,59,60]). A calculation considering an increase by 30% of the diffusion coefficient results in a 300 µm blister in 20h (Figure 6(d)).…”