1. Nagoya University, Department of Materials, Physics and Energy Engineering Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
2. Nuclear Fuel Industries, Ltd., 1-950 Asashiro-Nishi, Kumatori-cho Sennan-gun, Osaka 590-0481, Japan
3. Nuclear Engineering, Ltd., 1-3-7, Tosabori, Nishi-ku, Osaka-shi, Osaka 550-0001, Japan