Progress in Procurement of ITER Toroidal Field Coil in Japan

The Japan Atomic Energy Agency (JAEA) has a responsibility to procure nine International Thermonuclear Experimental Reactor (ITER) toroidal field (TF) coils and 19 TF coil cases. The JAEA started sub- and full-scale trials to qualify and optimize the manufacturing procedures of TF coils and TF coil cases from August 2012. The major outcomes of these trials are development of an automatic winding system with high accuracy in conductor length measurement ±0.01%, evaluation of the conductor elongation of about 0.06% due to heat treatment, demonstration of the manufacturability of a full-scale radial plate with high accuracy, and establishment of the TF coil case manufacturing procedure satisfying tight tolerances. The JAEA thus started the series production of TF coils from the end of 2013 and TF coil cases from the beginning of 2014. Until now, 11 double-pancake (DP) windings were completed, and seven DPs were heat treated with elongation of the conductor from 0.063% to 0.077%, which are well consistent with the expected values. In addition, three main bodies of the basic segments of TF coil cases are being assembled. These successful achievements indicate good progress in the procurement of ITER TF coils.