Manufacturing and acceptance by CEA of the first JT-60SA TF coils

Abstract

In the frame of the Broader Approach, CEA provides 9 Toroidal Field (TF) coils+1 spare for the JT-60SA tokamak. Mid 2011, a manufacturing contract was awarded to Alstom, Belfort, and now General Electric (GE). The first years were dedicated to the manufacturing process definition, the critical processes qualification through a set of 12 mockups, the manufacturing Quality Assurance (QA) definition and the procurement and commissioning of the tooling. Then, the production started early 2014.The manufacturing workshop was organized in 12 workstations. The production started with the preparation of the conductors provided by F4E and the winding in a stack of 6 Double Pancakes (DPs) which constitutes one Winding Pack (WP). The joints to connect electrically the DPs and the impregnations finalized the first WP. End 2014, acceptance tests related to geometry, tightness and electrical insulation validated the first WP for the following integration operations.The coil casings made under F4E to ENEA contract, were delivered as a set of components, including the U shaped straight and curved legs forming the D shape of the coil and the inner covers. After preparation, the WP was inserted vertically inside the casing straight leg lying horizontally. The curved leg and covers were then added to close the coil. The WP geometry and location in the casing were carefully controlled. The casing elements enclosing the WP were then welded either manually or by robots before performing the blocking impregnation. A final machining adjusted then the coil interfaces to the precise WP references. End 2015, after insulated piping integration, the final coil acceptance in terms of geometry, tightness and insulation allowed the delivery of the first coil at the Cold Test Facility (CTF), where the coils were tested at full current before final acceptance.This paper describes the first TF coils manufacturing process, the status of the production and provides first insights into the manufacturing feedback and the first coils performance results.