China has made a significant breakthrough in a key material area for its fourth-generation advanced nuclear energy systems. Special ERNiMo-2 nickel-based welding materials for thorium-based molten salt reactors, jointly developed by the Shanghai Institute of Applied Physics, Chinese Academy of Sciences and Baowu Special Metallurgy, have successfully passed a review by a panel of authoritative experts. This achievement breaks a long-standing foreign technological monopoly and realizes domestic substitution, laying a solid material foundation for the large-scale construction and commercial application of China's thorium-based molten salt reactors.

The review panel consisted of experts from several authoritative organizations in the nuclear energy field, including the Shanghai Welding Society, Shanghai Jiao Tong University, the Shanghai Nuclear Engineering Research and Design Institute, and the Shanghai Institute of Applied Physics. Following rigorous examination and comprehensive assessment, the expert panel unanimously concluded that the domestically produced ERNiMo-2 nickel-based welding material from Baowu Special Metallurgy fully meets the technical standards for molten salt reactors. Its key long-term performance characteristics surpass those of comparable imported products, with stable and reliable quality, and it has now demonstrated the capability for mass production and engineering application.

Welding materials serve as an invisible safety barrier for nuclear energy equipment. While seemingly minor, they are a core and critical material that determines the service safety, operational lifespan, and reliability of a reactor. In high-end nuclear engineering, welded joints, due to their process characteristics, are prone to stress concentration and microstructural gradients. This makes them one of the most vulnerable critical links throughout a device's entire service life, determining the reactor's load-bearing limits and service reliability. They represent an indispensable and key area in the pursuit of nuclear technology localization.

To overcome this critical material challenge, Baowu Special Metallurgy established a dedicated task force under the overall guidance of the reactor design from the Shanghai Institute of Applied Physics. The team focused on a series of key technologies, including material purity smelting, microstructural uniformity control, hot deformation, cold working, and full-process cleanliness control. By systematically breaking down technical barriers, the team successfully mastered the entire manufacturing process, ultimately achieving mass production capability.

The successful domestic production of the ERNiMo-2 nickel-based welding material completely breaks the dependence on imports, achieving autonomous and controllable supply within the critical material system for molten salt reactors. This breakthrough fully demonstrates the robust research, development, and manufacturing capabilities of China's high-end special metallurgical materials, providing solid material assurance and technical support for the high-quality and leapfrog development of the country's advanced nuclear energy industry.