Korea Hydro & Nuclear Power (KHNP) has successfully operated a nuclear power plant component manufactured using 3D-printing technology for 18 months without defects, marking the first long-term operational demonstration of a 3D-printed nuclear component in Korea.
The component is a multi-blade impeller used to cool the generator circuit breaker at Saeul Unit 1. The impeller plays a role in maintaining the operating temperature of the equipment by circulating cooling air.
KHNP developed the component in 2024 using additive manufacturing technology. Conventional products are assembled by attaching multiple blades to a fixed plate, meaning the connection points between the two structures can become potential weak spots. KHNP instead manufactured the fixed plate and blades as a single integrated component using 3D printing, eliminating the assembly joints and improving structural durability.
Before being installed at the nuclear power plant, the newly developed impeller underwent various verification procedures, including heat treatment, mechanical property testing and airflow performance testing. After completing the durability and performance evaluations, KHNP installed the component at Saeul Unit 1 in January 2025.
The 3D-printed impeller then operated continuously for 18 months until the plant entered scheduled preventive maintenance in July 2026. KHNP said no defects were identified during the operating period, demonstrating that the component can withstand long-term operation in an actual nuclear power plant environment.
The achievement is drawing attention because nuclear power facilities require particularly high levels of reliability and quality from their components. Industry observers say successful operation under actual plant conditions provides an important foundation for expanding 3D-printing technology beyond laboratory testing and prototype development.
Another advantage of 3D printing is its ability to produce complex structures as a single component. This can reduce the number of assembly points while allowing engineers to optimize designs that are difficult to manufacture using conventional methods. The technology could therefore offer new opportunities for improving the durability and performance of specialized nuclear components.
KHNP plans to use the results of the demonstration to expand the application of 3D-printed components to other nuclear power plants. The company intends to focus initially on components where improvements in performance or durability can provide clear benefits.
The company is also looking beyond replacement parts for existing reactors. KHNP plans to continue research into the use of 3D printing for newly designed components for next-generation nuclear technologies, including small modular reactors (SMRs).
Lee Dong-kuk, head of KHNP’s Central Research Institute, said the company would continue research and development to ensure that 3D-printing technology can be used not only to replace existing components but also to manufacture new components for next-generation reactors such as SMRs.
The successful 18-month operation represents a significant step toward bringing additive manufacturing into practical use in the nuclear power sector. Further operational experience and the development of appropriate standards and qualification procedures will be key to determining how widely the technology can ultimately be adopted.
