[2A01-05] Tritium Production

[2A03] Study on T production using high-temperature gas-cooled reactor for fusion reactors

(2) Hydrogen absorption properties of Ni coated hydrogen storage metals co-existed with oxides

*Teppei Otsuka¹, Kazuki Yamashita¹, Hideaki Matsuura², Kazunari Katayama², Minoru Goto³, Shigeaki Nakagawa³, Etsuo Ishizuka³, Shinpei Hamamoto⁴ (1. Kindai Univ., 2. Kyushu Univ., 3. JAEA, 4. Blossom Energy)

Keywords:tritium, hydrogen storage metal, nickel coating

When hydrogen storage alloys like Zr and Ti are co-existed with oxides and heated at high temperatures in a closed system, the alloy surface will be oxidized at elevated oxygen equilibrium partial pressure in the system due to decomposition of the oxides. In order to prevent this phenomenon, we have Ti powders of 40 micron in diameter be coated with nickel (Ni) layer of 0.3 - 3 micron in thickness with the wet chemical plating method and successfully demonstrated hydrogen storage in the Ni coated Ti powder co-existed with LiAlO₂ at the temperature range from 673 K to 873 K. It was also clarified that Ni-coated Ti particles may gradually lose the effect of Ni coating layer due to interdiffusion between Ni and Ti when heated at temperatures higher than 873 K. In the present meeting, we will discuss the utilization conditions (temperature and duration) necessary to maintain the effect of the Ni coating layer with the aid of numerical calculation results, and report on the hydrogen storage properties of NiTi alloys.