The influence of grain size and amount of beryllium oxide BeO on the tritium release characteristics of S-65H and I-220H beryllium grades was investigated. The beryllium samples were loaded with hydrogen at a temperature of 1123K for 6 h at a pressure of 4 bar in a gas mixture of molecular protium with 45ppm[wt] of tritium. The tritium release measurements were performed using a stepped heating ramp with steps of 50K in the temperature range of 473–1373K with a duration of each step of 1h. Five major release peaks were observed. Interpretations of the nature of the peaks were suggested. In particular, the low-temperature peaks (300–723K) were attributed to desorption from the surface and the shift of the peak at elevated temperature (900–1000K) was connected to the enhanced diffusion of hydrogen along grain boundaries. The high temperature peak (1123–1373K) was attributed to dissociation of beryllium hydroxide Be(OH)2, which was formed on the surface and grain boundaries of a sample in a reaction of hydrogen isotopes with beryllium oxide.

Temperature-Programmed Desorption of Tritium Loaded into Beryllium. V.Chakin, R.Rolli, P.Vladimirov, P.Kurinskiy, M.Klimenkov, A.Moeslang, L.Ryczek, C.Dorn, A.Markovsky: Physica Scripta, 2009, T138, 014035