Manufacturing of the Casing Components for the JT-60SA Toroidal Field Coils

The JT-60SA superconducting tokamak is being constructed in Japan under the Broader Approach agreement between Japan and the EU. ENEA is responsible for the in-kind supply of 18 toroidal field coil casings for JT-60SA, and contracted the company Walter Tosto (Chieti, Italy) for fabrication of two sets of nine casings each to be delivered to the coil manufacturers ASG Superconductors (Genoa, Italy) and Alstom (Belfort, France). After the completion of the detailed design of the casing components' stainless-steel materials were acquired and the manufacturing processes were qualified on mock-ups representative of the components. The complete resolution of all design and technical issues required the replacement of the forged stainless-steel material and a revision of the time schedule. On the basis of the manufacturing experience of the first two different sets of casing components, the production process has been improved, and the fabrication of the complete procurement is now ongoing. This paper reviews the main steps of the fabrication of the casing components, highlighting the critical issues encountered and reporting the status of the manufacturing activities.