Study on tritium confinement method using Li rod with Zr in HTGR; Hydrogen absorption properties of Zr in high temperature (700-900C) conditions

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

It has been proposed that lithium rods, which are cylindrical lithium compounds, are loaded into a HTGR and tritium for initial fusion reactors is produced by Li(n,)T reaction. In this study, it was discussed that the lithium rods are covered with zirconium layers to prevent the produced tritium leak. The solubility and diffusion coefficient of hydrogen in zirconium were measured and the effectiveness of the zirconium layers on prevention of tritium leakage was estimated with the measured values. As a result, the tritium leakage ratio with the zirconium layers was estimated two orders lower than that without the zirconium layers, and hence it was considered that the zirconium layer is very effective on the prevention of the tritium leakage.