On February 14, the 4 sets of STEP-12 nuclear fuel assemblies and the 4 sets of CZ zirconium alloy sample tube assemblies independently developed by the CGN Power Co., Ltd. (CGN Power) were officially installed in the unit 1 of Ling'ao NPP PhaseⅡ, now awaiting irradiation test. It indicated that CGN Power had fully grasped the technology for research, design, manufacture and testing of nuclear fuel assemblies, marking a major technological breakthrough in pursuing self-reliance in the field of nuclear power.

It was reported that after the irradiation test, the independently developed nuclear fuel assemblies and the sample tube assemblies would be subjected to a comprehensive examination, including visual inspection, measurement of thickness of the cladding oxide film and many other parameters, for a deep understanding of irradiation performance, and subsequently for optimized design.

According to reports, the development project for the STEP-12 nuclear fuel assembly and CZ zirconium alloy is an important part of China's national project for nuclear energy development, implemented on the basis of step-by-step principle in three stages, i.e., prototype assembly, finalized assembly and pilot assembly. During the design of the STEP-12 nuclear fuel assembly and CZ zirconium alloy, the project team fully drew on the existing operation and manufacture experiences, realized a number of major breakthroughs in design, verification, manufacturing, materials, etc., via intensive technology-specific researches, and achieved excellent out-of-reactor test performance.

STEP-12 nuclear fuel assembly and CZ zirconium alloy assembly are applicable not only in the improved Gen-II "CPR1000" nuclear power unit in commission, but also in HPR, the Gen-III flagship reactor independently developed by China. This technological breakthrough is of great significance for improving cost-effectiveness of nuclear power units of China in the future, and promoting the drive of Chinese nuclear power development overseas.