F4E Procurement of Radial Plates for the EU ITER TF Coils (October 2015)

This paper reflects the status of the manufacturing of 70 radial plates (RPs) for the EU ITER TF Coils. About 3700 t of stainless steel 316 LN have been forged and 240 t of cover plate (CP) raw material bars have been procured for the procurement of the RPs. Each RP is composed of six forged segments welded using local vacuum EB Welding technology for 35 RPs and narrow-gap TIG for the other 35 RPs. All RP plates are finally machined to final dimensions (9 m × 14 m) and tolerances using large portal milling machines. The groove length, planarity, and D-shape form tolerances are the most challenging required tolerances: ±30 ppm for the groove length and 1 mm for both planarity and D-shape form. The main challenges faced and results achieved so far are presented and improvements with respect to the prototype phase are described.