Russia is supplying 25 sophisticated high-tech systems for the International Thermonuclear Fusion Experimental Reactor (Iter), under construction in France. In St Petersburg, at the Sredne-Nevsky Shipbuilding Plant (SNSZ) specialists from SNSZ and from the DV Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA - part of Rosatom) have just completed the vacuum-injection impregnation of the winding of the superconducting coil for the magnetic system of the Iter reactor, Rosatom said on 19 March
Vacuum injection impregnation is one of the most difficult and critical stages of coil manufacturing, and was preceded by a number of technological stages completed last year. The 200-ton PF1 coil, with a diameter of 9 metres, is one of six coils of the poloidal field in the magnetic system, which serves to contain the plasma in the reactor. The coil is a complex product based on eight superconducting double-layer double-thread biscuits. For each of the 16 cables of the PF1 coil, a niobium-titanium superconductor was used manufactured in Russia, which has superconducting properties at ultra-low temperatures of about 4 Kelvin. Organisation involved included fuel company TVEL, Chepetsk Mechanical Plant, and the AA Bochvar Research Institute of Inorganic Materials (VNIINM), all part of Rosatom, as well as the Russian Scientific Research & Development Cable Institute (VNIIKP).
Because of the uniqueness of the product and the extremely high requirements imposed by the ITER Organisation, the manufacture of the coil of the poloidal field required the development and improvement of advanced technologies and technological processes. The most important technologies and equipment for manufacturing the coil were developed at NIIEFA.
Anatoly Krasilnikov, director of the Russian ITER Agency (part of the Rosatom), noted: “It is difficult to overestimate the successful completion of this stage of manufacturing the Russian coil. The main difficulty during the impregnation was that this is an irreversible operation; it would be impossible to alter anything in the event of failure. In other words, we simply had no room for error. But we had no doubts about the success, because a truly high-class team is working on the manufacture of the coil."
Vacuum injection impregnation of the PF1 coil is necessary to obtain electrical insulation with extremely high dielectric and mechanical strength. In the future, the production of the PF1 coil will go through a number of technological stages, followed by final assembly of the product and preparation for its shipment to Iter in France in the spring of 2022. Rosatom has been designated as the organisation responsible for fulfilling the Russia’s obligations in the ITER project. The work is coordinated by the ITER Project Centre, a private institution within Rosatom.