Hydrogen release from reactor-irradiated beryllium

Experiments on gas release of reactor-irradiated beryllium samples were carried out and compared to control samples. The simultaneous influence of reactor irradiation and exposure to hydrogen results in more hydrogen retention in beryllium, than if beryllium is initially irradiated and then exposed to hydrogen. Appearance of low temperature peaks at 460 K and 540 K with 0.71 eV/atom and 0.84 eV/atom desorption activation energies, respectively, assessed in a frame of a second order desorption model, is mainly responsible for the increase in hydrogen content. These peaks can be attributed to chemical hydrogen bonds with surface oxide. The simultaneous influence of hydrogen and nuclear reactor irradiation at a temperature of 1150 K was assumed to increase significantly microcrack formation near the surface of beryllium samples, resulting in an increase in low temperature peak intensities.