Hydrogen and deuterium permeation measurements on the double-wall tubes material for the water-cooled Pb-17Li DEMO blanket

The aim of this study is to measure the hydrogen/deuterium transport and in ventory parameters in the double-wall tubes (DWT) material for the water-co oled Pb-17Li DEMO blanket. Measurements are conducted using a time dependen t permeation method over the temperature range 473-723 K, with hydrogen and deuterium driving pressures in the range 1-10(5) Pa (0.01-1000 mbar). The samples are also characterised using optical microscopy, SEM, microhardness measurements and mechanical tests. An effective permeability of about 12 t imes lower than 2.1 mm of bare F82H steel at 573 K and three times lower th an 2.1 mm of bare F82H steel at 723 K have been measured. This result is cl ose to the theoretical prevision (multi-layer model). (C) 2000 Elsevier Sci ence B.V. All rights reserved.