Trapping and radiation-induced detrapping of hydrogen in stainless steel exposed to liquid lithium

• Published in: Journal of nuclear materials Vol. 101; no. 3; pp. 350 - 353
• Main Authors: Miki, T., Ikeya, M., Touge, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1981
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/0022-3115(81)90176-8

Liquid Li is one of the candidates for the coolant and tritium breeder materials in a future fusion reactor. However, when liquid Li contacts metals, the Li penetrates into the grain boundaries and reacts with nonmetallic impurities, such as oxygen, nitrogen and carbon-forming corrosion products. The resultant corrosion products act as a surface barrier for H migration and lower the permeability of H and its isotopes. This investigation studies H behavior in 316 type stainless steels exposed to liquid Li. It was observed that deep traps for H are introduced during exposure and that X- or gamma -irradiation can be used to release the trapped H. It is concluded that radiation-induced H detrapping would be due to either the electronic excitation of metal--H quasimolecules into antibonding states or momentum transfer from photoelectrons and Compton electrons to H atoms in metals. 20 ref.--G.G.M.