Study on tritium confinement method using Li rod with Zr in very high temperature gas-cooled reactor; Hydrogen storage properties of Zr in high temperature (700850C) conditions

Okamoto, Ryo*; Matsuura, Hideaki*; Ida, Yuma*; Koga, Yuki*; Katayama, Kazunari*; Otsuka, Teppei*; Goto, Minoru  ; Nakagawa, Shigeaki  ; Ishitsuka, Etsuo   ; Nagasumi, Satoru; Shimazaki, Yosuke 

Currently, many researches to achieve DT nuclear-fusion power generation are under proceeding but the method to provide initial tritium loaded to fusion prototype reactor is not clear. The method of tritium production by using high temperature gas-cooled reactor (HTGR) was proposed. In this method, lithium rods are loaded to the reactor core of HTGR and tritium is produced by Li(n,)T reaction. And the method to reduce the spilled tritium by using the lithium rod with zirconium layer was proposed. In this study, the experiments to evaluate the performance of hydrogen absorption in the zirconium layer were conducted under the temperature condition more than 700C which is the normal operation condition for the very high temperature gas-cooled reactor (VHTR). The experimental result concerning solubility and diffusion factor of hydrogen in the zirconium layer will be presented and discussed.