Status Report on the Toroidal Field Coils for the ITER Project

The magnet system for ITER comprises 18 Toroidal Field (TF) Coils using Nb₃Sn cable-in-conduit superconductor, which operate at 4.5 K in supercritical helium. The procurement of the TF Coils and Structures is amongst the first which have been launched following the creation of the ITER Organization (IO). It is organized in 4 phases. A Procurement Design Readiness Review held in April 2008 confirmed the readiness of the design to proceed with Phases I and II. Procurement Arrangements (PA) were signed with the European and Japanese Domestic Agencies (DA) respectively in June and November 2008. After a brief description of the TF Coils and Structures, the paper gives an overview of the PA showing the milestones towards series production. The procurement strategy of both DA involved is described, in particular the first step which covers pre-production activities: qualification of raw materials, manufacturing trials, mock-ups and full-scale prototype radial plates, impregnation tests and, possibly, winding trials. The work carried out by IO is also presented: optimization of the cover plate welding to satisfy the allowable stress criteria while minimizing the associated distortions, qualification of blends of cyanate ester with epoxy resin for the impregnation of the winding packs and design of the coil terminal region including integration of the needed instrumentation.