1. Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, Heilongjiang, P. R. China
2. China Institute for Radiation Protection, Taiyuan 030006, Shanxi, P. R. China
3. Yantai Standard Metrology Inspection & Test Center, National Steam Flowrate Measurement Station, Yantai 264000, Shandong, P. R. China