Speaker
Yu Otani
(Prime Mover Engineering)
Description
Lithium metatitanate (Li2TiO3) is one of the candidate materials among the solid tritium breeders proposed because of its good tritium release property and high chemical stability [1]. Lithium metatitanate with excess Li (Li2+xTiO3+y) has been recognized as an another prominent candidate material owing to its higher Li density [2]. Demonstration power plant (DEMO) reactors require tritium breeders with high mechanical stability under operating conditions. However, their compression fracture strengths are feared to be reduced by Li vaporization during operation at high temperature.
In this work, the compression fracture strength changes of the pebbles of Li2TiO3 and Li2+xTiO3+y under operating conditions were investigated. The pebbles were thermally annealed in a gas flow of 1%H2/He at 900ooC for various time, and the compression fracture strength was measured by using an universal testing machine at room temperature. Mass decrease by Li vaporization was measured by gravimetric method, and crystal-phase change was analyzed by XRD.
When the sintering density was below 78%, the compression fracture strength and apparent Young's Modulus were significantly small. Therefore, the pebbles with sufficiently large and constant sintering density (83−85%) were used in this study.
[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.
Co-authors
Kazuya Sasaki
(Prime Mover Engineering, School of Engineering, Tokai University, Hiratsuka, Kanagawa, Japan)
Kiyoto Shin-mura
(Prime Mover Engineering, School of Engineering, Tokai University, Hiratsuka, Kanagawa, Japan)
Seiya Ogawa
(Prime Mover Engineering, School of Engineering, Tokai University, Hiratsuka, Kanagawa, Japan)
Tsuyoshi Hosino
(Fusion Research and Development Directrate, Japan Atomic Energy Agency, Rokkasho-mura, Aomori, Japan)
Yu Otani
(Prime Mover Engineering, School of Engineering, Tokai University, Hiratsuka, Kanagawa, Japan)
