1. Reactor Safety Analysis and Evaluation Group, Japan Atomic Energy Agency, Narita-cho, Ibaraki 311-1393, Japan
2. Sino-French Institute for Nuclear Energy and Technology, Sun Yat-sen University, Zhuhai 519082, China
3. Department of Nuclear Engineering and Management, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
4. United Kingdom Atomic Energy Authority, Unit 2a Lanchester Way, Advanced Manufacturing Park Catcliffe, Rotherham S60 5FX, UK