Absorption of molten fluoride salts in glassy carbon, pyrographite and Hastelloy B

Materials performance is one of the issues of the accelerator driven transmutation technology (ADTT). Identification of the materials, which would satisfy the strength and integrity requirements for the target–blanket assembly (e.g. corrosion and radiation resistance), is a significant challenge. We report on the study of the interaction (i.e. penetration and capture) of molten fluoride salts with glassy carbon, pyrolitic graphite, and Hastelloy B, which are considered as candidates for structural materials of the ADTT systems. Massive penetration into and capture of molten fluorides within a several micrometer thick surface layer was observed for all inspected specimens. The incorporation rate of the molten fluorides depends on the exposure time and temperature of the molten fluoride bath. The corrosion resistance of the specimens was verified in stationary conditions. Whereas excellent resistance has been found for pyrolitic graphite, evident corrosion was observed for glassy carbon and particularly for Hastelloy B.