1. Kyoto University, Research Reactor Institute, Noda, Kumatori-cho, Sennan-gun Osaka 590-0494, Japan
2. Commissariat à l’Energie Atomique/DRN/DER/SPEx Centre d’Etudes de Cadarache Building 238, 13108 St.-Paul-lez-Durance, France
3. Musashi Institute of Technology, Department of Energy Science and Engineering 1-28-1, Tamazutsumi, Setagaya-ku, Tokyo 158-8557, Japan
4. Osaka University, Graduate School of Engineering, Department of Nuclear Engineering 2-1, Yamada-oka, Suita, Osaka 565-0871, Japan