On July 25, the world’s first magnet cold test dewar for the International Thermonuclear Experimental Reactor (ITER) project was dispatched from Shanghai Electric Nuclear Power Equipment Co., Ltd. The successful development and delivery of this equipment marks that China has reached an internationally leading level in the precision manufacturing of ultra-large nuclear fusion devices, providing critical technical experience for future fusion reactor projects.

As a flagship international cooperation project for humanity’s quest for clean energy, ITER includes a magnet cold test system as a core part for verifying the reliability of superconducting magnets. The dewar, a large cryostat, is the key component of this system. Its primary functions are to provide a stable vacuum environment for superconducting magnet testing and to ensure the safety of the system under extreme conditions such as helium leakage or plasma disruption. The quality and delivery timeline of this equipment are directly critical to the overall success of the magnet cold test system.

To meet the stringent requirements of the project, Shanghai Electric formed a high-caliber project team together with the Institute of Plasma Physics of the Chinese Academy of Sciences (ASIPP) and the ITER Organization, adopting a “nuclear intelligence co-creation” collaborative innovation model. Leveraging ASIPP’s technical reserves and ITER’s international standards, the team overcame multiple technical challenges in just 11 months, including: millimeter-level precision forming of large contoured surfaces, deformation control during large shell assembly and welding, large-diameter flat flange welding deformation control, ultra-large vessel vacuum pumping and helium leak detection. As a result, the main structure achieved millimeter-level deformation control and ultra-high vacuum sealing performance of 10⁻⁴ mbar, meeting the world’s highest standards.

The successful delivery of the ITER magnet cold test dewar by Shanghai Electric not only stands as a model of collaboration between Chinese and international scientific institutions and enterprises but also showcases the speed and strength of “Made in China” in the field of extreme manufacturing. Looking ahead, Shanghai Electric will continue to leverage its technological expertise and collaborative strengths to deeply participate in China’s key fusion projects, advancing toward the commercial application of the “artificial sun” and contributing to global sustainable development.