Vacuum pressure impregnation completed of ITER’s poloidal field coil PF1


The smallest poloidal field magnet —PF1— of the International Thermonuclear Experimental Reactor (ITER), or the world’s largest nuclear fusion project currently being assembled at Cadarache, France, has successfully undergone vacuum pressure resin impregnation at the Sredne-Nevsky Shipyard in St. Petersburg in Russia, according to the Russian state atomic energy corporation Rosatom.

A Rosatom statement said that the 200-tonne poloidal field coil 1 (PF1) is one of six poloidal field coils designed for plasma confinement in the ITER machine. Nine metres in diameter, the magnet is a complex system whose building blocks — 8 double pancakes wound from niobium-titanium cable-in-conduit conductor — have been stacked and joined electrically last month with over 6 kms of superconductor being used during winding of the PF1.

The machine assembly of the ITER “tokamak” nuclear fusion reactor, which began in July last year, is designed to replicate the fusion power of the sun in order to enable generation of clean unlimited energy, and the first ultra-hot plasma is expected to be generated in late 2025. The world’s largest science project is intended to demonstrate that fusion power can be generated on a commercial scale.

According to Rosatom, acting inside of a vacuum mould and under the effect of heat, epoxy resin hardens the coil winding pack into a rigid assembly and ensures its electrical insulation. “Vacuum impregnation of PF1 coil is necessary to obtain electrical insulation with extremely high dielectric and mechanical strength. The production of the PF1 coil will go through a number of technological operations in the future. Then, after final assembly, the system will be prepared for its shipment to the construction site of the ITER machine in the south of France in 2022”, the statement said.

“The manufacture of a poloidal field coil due to the uniqueness of the product and the extremely high requirements imposed by the ITER Organization, required the development and improvement of advanced technologies and technological processes. The most important technologies, as well as the equipment for manufacturing were developed at the D.V.Efremov Institute of Electrophysical Apparatus”, it added.

“It’s hard to overestimate the importance of this stage of Russian poloidal field coil manufacturing. The main difficulty during the impregnation was an irreversibility of the operation; it would have been impossible to alter anything in case of failure. But we had no doubts that we would succeed, because a truly high-class team is working on the manufacture of the coil”, said Anatoly Krasilnikov, Head of the Russian ITER Domestic Agency.

ITER’s realising of a self-heating plasma is expected to generate 10 times more heat than is put in. Fusion provides clean, reliable energy without carbon emissions, with minute amounts of fuel and no physical possibility of an accident with meltdown.The fuel for fusion is found in seawater and lithium, while it is abundant enough to supply the world for millions of years. A football-sized amount of this fuel is equivalent to around 10,000 tons of coal.

Millions of components from all over the world will be used to assemble the giant reactor, which will weigh 23,000 tonnes. It is a concrete demonstration of the willingness of ITER’s 35 partner countries to join together in an enduring way in their common fight against climate change and for access to limitless clean energy.