Tritium and helium release from highly neutron irradiated titanium beryllide

摘要

Beryllium, Be5Ti, and Be7Ti as pellet specimens have been irradiated at the HFR, Petten, the Netherlands at temperatures of 684-959 K up to 301 appm tritium and 3060 appm helium productions. For beryllium, under thermal desorption tests only one major peak was revealed either for tritium and helium release. Both peaks are located at the same temperatures of 1250-1350K. The Be-Ti microstructure contains two phases, mainly titanium beryllide Be12Ti and also small addition of beryllium. First helium release peak as well as the tritium release peak is detected at 1000-1100 K. Second helium release peak is revealed at temperatures of 1350-1370K. A conclusion was made that the facilitated tritium escaping from Be-Ti specimens is caused by accelerated diffusion of tritium through the channels formed in the beryllium phase under irradiation. This suggests a positive role of small additions of beryllium phase in Be-Ti intermetallic compounds that minimizes the finale tritium inventory. (C) 2015 Elsevier B.V. All rights reserved.