The steam-blowing operation for the secondary-circuit main steam piping of Hainan Changjiang Nuclear Power Unit 4 has been successfully completed.

On July 23, the "shock blow" cleaning operation for the secondary-circuit main steam piping of Unit 4 at the Hainan Changjiang Nuclear Power Plant—undertaken by China Nuclear Industry Fifth Construction Co., Ltd.—was successfully completed. The cleanliness of the system piping met all relevant specifications and standards. By achieving this critical construction milestone on schedule, the project has laid a solid foundation for subsequent cold and hot functional testing, as well as the unit's smooth grid connection and commercial operation.

The Phase II project of the Hainan Changjiang Nuclear Power Plant is a key national energy project under the "14th Five-Year Plan" and serves as a benchmark clean energy project for the Hainan Free Trade Port. Unit 4 utilizes "Hualong One" technology, my country's indigenous third-generation nuclear power design. The secondary-circuit main steam system acts as the core thermal pathway connecting the steam generator to the turbine; it features complex piping and precision equipment, requiring rigorous safety and quality controls. Internal piping cleanliness directly impacts the long-term operational reliability of turbine blades and precision valves, making the shock blow cleaning process a critical step in ensuring the unit's safe and stable operation.

To guarantee construction quality and meet schedule targets, the project management team organized advance reviews of the execution plan and conducted thorough on-site simulations. Throughout the construction process, the project department strictly adhered to nuclear safety and quality management systems and construction standards, ensuring meticulous control over every stage of the piping cleaning process. Focused on their objectives and seizing optimal construction windows, the team systematically advanced tasks—including piping prefabrication, fit-up and installation, non-destructive testing, valve isolation, shock blow cleaning, quality acceptance, and system restoration—thereby maintaining a stable safety record and ensuring controllable engineering quality throughout the project.

The successful completion of the shock blow cleaning for the secondary-circuit main steam piping has comprehensively verified the installation quality of the main steam system for Unit 4, resolved a critical bottleneck for system commissioning, and further satisfied the prerequisites for the unit's cold functional testing.