Diffusion of H in Zircaloy-2 and Zr-2.5%Nb rolled plates between 250 °C and 350 °C by off-situ neutron imaging experiments

Kinetics of hydrogen absorption/desorption in the Zr–2.5Nb alloy

“…Geometric shrinkage is the primary mechanism of the reaction between Zr–2.5Nb and deuterium in the temperature range of 100 to 550 °C, which is consistent with the previously published experimental findings. At the same time, deuterium diffuses into the interior of the particle driven by the concentration gradient, although according to the diffusion coefficients measured by Shukla 31 and Santisteban, 32 deuterium diffusion in the powder particles can quickly reach a steady state, but below 100–550 °C, deuterium mainly forms deuteride precipitation, and only a small amount of deuterium exists in the solid solution state and participates in diffusion. Therefore, the diffusion process is not the main limiting factor of the reaction.…”

Hydrogen diffusion in Zr-2.5Nb pressure tubes specimens between 300°C-400°C by in-situ neutron imaging experiments

“…H content profiles at different total times from the beginning of the TT are shown in figures 7 and 8 for PT-T and PT samples, respectively. TSS values were determined from the inflexion point and the plateau formed after the transition zone [9] and they are indicated in figures 7 and 8. TSS values obtained increase with the temperature increasing, and are similar to those reported in the literature for the PT sample [10].…”