China has completed construction of the final batch of magnet-supporting products for the International Thermonuclear Experimental Reactor (ITER) project under construction in France. The consignment has been shipped to the ITER construction site from Guangzhou City in Guangdong Province. China, as a partner in the project, is responsible for the development and manufacturing of the entire magnet supporting system for ITER.

ITER – under construction at Saint-Paul-les-Durance in southern France – is a first-of-a-kind global collaboration to construct the world’s largest tokamak based on magnetic confinement technology. It is funded mainly by the European Union (45.6%) with the remainder shared equally by China, India, Japan, Korea, Russia and the USA (9.1% each). However, in practice, the members deliver little monetary contribution to the project, instead providing ‘in-kind’ contributions of components, systems or buildings.

The ITER magnet support system is designed and manufactured by the Southwest Institute of Physics (SWIP), which is part of the China National Nuclear Corporation (CNNC). This system includes 18 sets of gravitational supports, 72 sets of supports for the coils of the canopy field and 18 sets of supports for the coils of the corrective field. The system, weighing more than 1,600 tonnes, is one of the core structural safety components of ITER and will be first key part to enter into a factory for installation. Since 2018 SWIP has delivered more than 30 batches of such products to ITER.

As the head of the relevant scientific project Li Panjuan explained, this system is the load-bearing frame of the entire ITER device. The magnet support system is designed primarily to hold superconducting magnets and is essentially an analogue of the foundation in the house. Also, this system must shield all foreign magnetic fields, thus ensuring a stable and safe flow of thermonuclear reaction in the ITER reactor.

China joined ITER in September 2007, and its manufacturing tasks include many important components of the device, such as the superconducting magnet system, large-scale coil power supply system and diagnostic system, according to Li. China has been involved in the research and development of some core technologies and undertaken 18 key tasks, accounting for 9% of the contribution, he added.

Over 100 Chinese scientists were sent to France to participate in the project. "Now we are at the forefront of the world in many fields, including superconducting magnets, material technology, power supply technology and control," Li said.

ITER is intended to demonstrate the feasibility of fusion as an energy source. The target is to operate at 500 MW (for at least 400 seconds continuously) with 50 MW of plasma heating power input. However, it will not supply electricity. Initially, it was announced that the “first plasma” was planned for 2025 and the launch of the deuterium-tritium thermonuclear reaction in 2035, but these deadlines have been postponed after defects were identified in two key tokamak components – the thermal shields and the vacuum vessel sectors. New deadlines are expected to be announced in 2024.

Image: The final consignment of magnet-supporting components for the International Thermonuclear Experimental Reactor begins its journey to France from China (courtesy of CNNC)