Dummy toroidal field conductor completed by Nippon Steel
The Japanese Domestic Agency and Nippon Steel Engineering last week completed the compaction and spooling of the first dummy copper conductor unit (760 metres) for ITER's toroidal field coils at the Wakamatsu plant.
The applied pull-through and compaction process was originally developed for the ITER model coil conductors. It consists of assembling a straight and long conduit by butt welding tube sections, then pulling the superconductor cable through the whole conduit length and finally compacting the long tube onto the cable by passing both of them though the rolls of a compaction head, and simultaneously spooling the compacted cable-in-conduit.
The Japanese Domestic Agency has set up a 900-metre-long industrial jacketing line near the town of Wakamatsu to fabricate the Japanese share of toroidal field and central solenoid conductors. The line has been designed, fabricated, installed and commissioned by Nippon Steel Engineering. It includes not only fabrication tools but also inspection and test equipment (e.g., non destructive examination of welds).
The completion of the first ITER dummy toroidal field conductor unit length is a necessary step before superconductor cable-in-conduit is fabricated. This is full scale verification of the process application as well as the equipments and tooling. The Nippon Steel team completed the various fabrication steps successfully, assembling the 316LN tubes produced by Kobe Special Tube Co., Ltd., inserting the dummy cable fabricated by Hitachi Cable at 2m/min, and eventually applying the compaction and the final spooling.
Thanks to the high level of preparation of the Nippon Steel team all steps went very smoothly. The next challenge is now to fabricate the first superconductor cable-in-conduit lengths which are scheduled in February.
