1. Tohoku University, Aoba, Armaki, Aoba-Ku, Sendai 980-8579, Japan
2. Department of Mechanical Engineering, Tohoku University, Aoba, Armaki, Aoba-Ku, Sendai 980-8579, Japan
3. Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
4. Heavy Apparatus Engineering Laboratory, Toshiba Corporation, 1-9 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
5. Isogo Nuclear Engineering Center, Toshiba Corporation, 8 Shinsugita-cho, Isogo-ku, Yokohama 235-0032, Japan