Speaker
Kiyoto Shin-mura
(Course of Mechanical Engineering)
Description
Lithium metatitanate (Li2TiO3) is one of the candidate materials for solid tritium breeder proposed because of its good tritium release property and high chemical stability [1], and Lithium metatitanate with excess Li (Li2+xTiO3+y) has been recognized as a prominent candidate material owing to its higher Li density [2]. However, demonstration power plant (DEMO) reactors require tritium breeders with higher lithium density.
From the view point of Li density, Li8ZrO6 and Li5AlO4 are promising chandidates for the breeder. However, it is concerned that the high lithium densities of these materials cannot be maintained, because they have high Li vapor pressure. Ogawa et al reported that stable phases with low Li vapor pressure surrounding the unstable phase prevents the Li vaporization from the breeder [3].
In this work, Li vaporization ratios from sintered compacts of the single phases of these candidate materials and the complexes of the high-Li-density phase and stable phase (Li2TiO3) were measured. Mass decrease by Li vaporization was measured by gravimetric method, and crystal-phase change was analyzed by XRD.
From some sintered compacts, the ratio of mass decreases by the Li vaporization became small after significant decreases confirmed in an initial 30 h. These results suggest the possibility of a new advanced tritium breeder with high Li density.
[1] N. Roux, J. Avon, A. Floreancig, J. Mougin, B. Ravel, J. Nucl. Mater., 223-237 (2) (1996) 1431-1435.
[2] T. Hoshino, M. Yasumoto, K. Tsuchiya, K. Hayashi, H. Nishimura, A. Suzuki, T. Terai, Fusion Eng. Des., 82 (2007) 2269-2273.
[3] S. Ogawa, Y. Masuko, H. Kato, H. Yuyama, Y. Sakai, E. Niwa, T. Hashimoto, K. Mukai, T. Hoshino, K. Sasaki, Fusion Eng. Des., 98-99 (2015) 1859-1863.
Co-authors
Kazuya Sasaki
(Course of Mechanical Engineering, Tokai University, Kanagawa, Hiratsuka, Japan)
Kiyoto Shin-mura
(Course of Mechanical Engineering, Tokai University, Kanagawa, Hiratsuka, Japan)
Seiya Ogawa
(Course of Mechanical Engineering, Tokai University, Kanagawa, Hiratsuka, Japan)
Tsuyoshi Hosino
(Fusion Research and Development Directrate, Japan Atomic Energy Agency, Rokkasho-mura, Japan)
Yu Otani
(Course of Mechanical Engineering, Tokai University, Kanagawa, Hiratsuka, Japan)
