Tritium release properties of neutron-irradiated Be12Ti

Be12Ti has a high melting point and good chemical stability and is a promising advanced material for the neutron multiplier of the DEMO reactor that requires temperatures higher than 600 °C in a blanket. To evaluate the tritium inventory in the breeding blanket, a tritium release experiment of neutron-irradiated Be12Ti with a total fast fluence of about 4×1020 n/cm2 (E>1 MeV) was carried out at 330, 400 and 500 °C. It was clear that tritium could be released easier than from beryllium, and the apparent diffusion coefficient in Be12Ti was about two orders larger than that in beryllium at 600–100 °C. In addition to the good tritium release property, the swelling calculated from the density change of the specimens up to 1100 °C in this test was smaller than that of beryllium.