——Expert Review of CAP1000 Primary Piping Single-Loop Six-Weld Simultaneous Joining Verification Test Summary and Construction Plan Passed; Formally Ready for Engineering Application

A major milestone has been achieved in the key technology development of the "six-weld simultaneous joining" process for the CAP1000 reactor coolant loop primary piping. On June 28, 2026, the core process and construction plan, led by CNPE and collaboratively developed with CNI23 and Raymond-CBE were reviewed in two high-level expert appraisal sessions held successively at the Liaoning Xudabao Nuclear Power Plant site. Both reviews received unanimous approval from the expert panels. This marks the official transition of China's independently mastered active thermal-deformation vector-controlled simultaneous fit-up and welding technology for primary piping from design verification to engineering implementation.

• Moving      from Single-Weld Sequential Execution to Six-Weld Parallel Operation

As the "main artery" of a nuclear power plant, primary piping installation welding has long occupied the longest single item on the nuclear island construction schedule and represents the highest challenge in precision control. The traditional approach uses step-by-step sequential welding of individual joints, resulting in prolonged cycle times. The "six-weld simultaneous joining" technology, based on active control of pipe thermal-deformation vectors, innovatively achieves simultaneous fit-up and simultaneous welding of six girth welds on a single loop, converting "serial" operations into "parallel" ones. This can substantially compress construction durations, accelerating nuclear power construction.

• Two      Back-to-Back Expert Review Sessions with Authoritative Panels

The reviews were held intensively in two sessions, one in the morning and one in the afternoon. At 9:00 AM, the review of the Six-Weld Simultaneous Joining Verification Test Summary Report was chaired by Mr. Jia Jingjing, Senior Supervisor of CNPE. At 2:00 PM, the review of the Primary Piping Single-Loop Six-Weld Simultaneous Joining Construction Plan was chaired by Mr. Wu Shuo, Chief Engineer of the Xudabao Project Department of CNI23.

 The expert panels for both sessions were highly authoritative, consisting of researcher-level or senior industry specialists, including: Sun Hanhong (former State Nuclear Power Technology Corporation), Zhang Wenqi (Nuclear Power Institute of China), Wang Zhanyun (Nuclear Engineering Construction Specialized Committee), Du Ailing (China Academy of Machinery Science and Technology), Yu Yan (SPIC Thorium-Based Energy Technology Co., Ltd.), Li Yuwei (CGN Engineering Co., Ltd.), and Li Jiahua (Shanghai Nuclear Engineering Research & Design Institute Co., Ltd.).

 Representatives from all participating parties attended, including Tian Peng, Sun Chengke, Sun Xiang, and Chen Binglong from CNPE; Zhang Weidong, Qian Long, Liu Qilin, Wang Zhichao, and Hou Bingbing from CNI23; and Zhou Wen, Wang Shuangjian, and Ju Yanxu from Raymond-CBE (Chief Technology Officer and team).

• Authoritative      Review Conclusion: Ready to Guide Construction and Enable Engineering      Implementation

After thorough questioning and discussion, the expert panels reached a unanimous review conclusion: The Verification Test Summary Report is comprehensive in content and detailed in data; the six-weld simultaneous joining technology demonstrates significant effectiveness in improving fit-up accuracy, ensuring welding quality, and shortening construction schedules, and is now ready for implementation in primary piping installation projects for CAP-series reactor types.

 The Construction Plan is complete in content, reasonable in process, feasible in measures, and compliant with applicable regulations and standards; it is unanimously approved and can guide on-site construction.

 The successful passage of both reviews has laid a solid foundation for the finalization of the primary piping construction plan for Unit 2 of the Xudabao Nuclear Power Plant and marks another independently controllable "hardcore" achievement in China's third-generation nuclear power core construction technologies. Raymond-CBE, as a core member of the technology development collaboration, will continue to deepen cooperation with all parties and actively promote the application of the six-weld simultaneous joining technology in more CAP-series nuclear power projects, contributing its "Raymond-CBE strength" to the high-quality development of China's nuclear power industry.

Raymond-CBE consistently upholds its corporate spirit: "Do hard things, and success comes easier." With nearly three decades of deep engagement in the nuclear energy field, the company remains committed to tackling major engineering challenges, providing a steady stream of momentum for the high-quality development of China's nuclear power industry through robust technical capabilities.