1. Toshiba Corporation Power Systems Company, Nuclear Core Engineering Group Nuclear Safety System Design and Engineering Department, Isogo Nuclear Engineering Center, 8, Shinsugita-Cho, Isogo-ku, Yokohama 235-8523, Japan
2. Toshiba Corporation Power Systems Company, Core and Fuel Technology Group Nuclear System Technology R&D Department, Power and Industrial Systems Research and Development Center, 4-1, Ukishima-Cho, Kawasaki-ku, Kawasaki 210-0862, Japan