A robust detection system is under development to protect the ITER magnets in case of quenches—those events in a magnet’s lifetime when superconductivity is lost and the conductors return to a resistive state.
Having recently celebrated its fifth anniversary, the ITER Project has moved steadily from negotiations to real manufacturing, and from dummy testing to production of the tokamak’s construction elements.
One of the first systems to be manufactured in line with the ITER Organization (IO) Integrated Schedule Plan is the superconductor for the ITER magnet system. Russia has demonstrated high stability and reliability during this process, fulfilling all its obligations in time. This has not only been acknowledged by the IO experts, but also by the international superconductor community.
The Russian Toroidal Field (TF) conductor with bronze route strands was tested in the SULTAN facility by Centre de Recherches en Physique des Plasmas- Ecole Polytechnique Fédérale de Lausanne (CRPP-EPFL) in late September — early October 2012. This is the fourth Russian sample to be tested in SULTAN but the first sample containing two sections of conductor made of real production length which will be used to manufacture real TF coils for the machine. The left section of the conductor was cut from side Double Pancake pre-production conductor (Phase III) while the right section was made from first production (Phase IV) regular Double Pancake.
The results obtained with the the TFRF4 (Toroidal Field Russian Federation # 4) sample show very good agreement with results of the two last samples TFRF2 and TFRF3, which demonstrated the relatively good stability of the conductor during electromagnetic cycling, as well as its good durability during the warm-up/cool-down procedure.
Testing the TFRF4 sample was a very important milestone which completed the pre-production phase of the TF conductor procurement process. This means we can now proceed to the final production stage. At the same time, it opens the way to start shipping the real conductors to the coil manufacturer so they can be used to make coils for the ITER tokamak.
The traditional International Conductor meeting was held in Moscow on 10-13 September, 2012. The regular meeting was attended by representatives from the ITER Organization, experts from the ITER Domestic Agencies of Europe, China, Japan, Republic of Korea, Russia and USA, as well as specialists from the DAs’ suppliers.
Such meetings are particularly important since the ITER magnetic system, with conductors forming its core, is one of the ITER tokamak’s key elements. The manufactured conductors, which are designed to withstand super high current in continuous mode, have to meet the IO’s strict requirements.
At the moment, 10 out of the 11 conductor Procurement Agreements, are either well into the production phase or are completing the qualification/pre-production phase. This is particularly true for the Toroidal Field conductors, where 75 percent of the required Nb3Sn strands and one third of the cable-in-conduit conductor unit lengths have been completed. Also, a technical solution has been found for the Central Solenoid conductors that are being implemented by the ITER Japanese partner.
„This is a clear indication that the ITER project is moving ahead and is able to keep schedule”, says the meeting’s Chair Arnaud Devred, ITER Superconductor Systems and Auxiliaries Section Leader.
In Devred’s opinion, „in spite of the difficulties of coordinating work with about 30 suppliers and six DAs around the world, the ITER conductor community has always tried to work in a cooperative and synergetic manner, and the conductor meetings have always been a great opportunity for sharing experience and tackling difficult interface issues.
The conductor meeting is also an opportunity to showcase the work done in the Russian Federation and for the DAs involved in coils procurement to visit the conductor production facility”. Russia is responsible for the procurement of 22 kilometres of conductors, destined for Toroidal field (TF) coils, and 11 kilometres destined for the Poloidal field (PF) coils of the ITER magnet system. TF coils include more than 90 tons of superconducting Nb3Sn strands; PF coils include 40 tons of Nb-Ti strands.
Arnaud Devred highly praised the progress achieved by the Russian suppliers saying that „The Russian Domestic Agency has now entered full TF conductor and PF cable production. It is a proactive partner, eager to play collectively and to assume its role within the ITER collaboration”.
The next regular meeting is planned for March 2013 in Cadarache.
The Russian captain has answered the question more than a thousand times but he obviously likes to tell the story: the Echion, his 3,000-ton cargo ship, owes her name to one of the Argonauts, the ancient Greek heroes who accompanied Jason on his quest for the Golden Fleece.
The Echion docked last Saturday at the Mediterranean port of La Seyne-sur-Mer, 65 kilometres east of Marseille. The load she was to take delivery of sat just on the other side of the road — a 21st century highly sophisticated piece of equipment in a 19th century steel and red brick hall that Gustave Eiffel (of Eiffel Tower fame) designed a century and a half ago.
The component was produced by Constructions Industrielles de la Méditerranée (CNIM), under a contract awarded by F4E, the European Domestic Agency for ITER, three years ago. Another European company, the Italian SIMIC S.P.A, also produced a Radial Plate Prototype using different technologies.
This approach enables the Domestic Agencies in charge of procuring the actual ITER components to select the best solution before the industry launches into series production — the 19-Coil (plus spare) TF system in ITER will require the manufacturing of 134 Radial Plates, 70 to be procured by Europe, 64 by Japan.
Radial Plates are D-shaped stainless steel structures with grooves machined on both sides, into which insulated superconductor cables are inserted at a later stage. They are 112 mm thick, weigh between 5.5 and 9.7 tons and measure 8.7 by 13.8 metres.
Each of the ITER TF Coils contains seven radial plates, five „regular” and two „side” plates arranged in „double pancakes”.
Once the Echion reaches Italy’s Ligurian sea, the radial plate prototype will be delivered to the ASG Superconductor plant at La Spezia where the 450 metres of conductor will have to be shaped according to the groove trajectory, then heat treated, electrically insulated and finally inserted into the grooves.
Loading operations at La Seyne began on Monday 3 September in the middle of the night. While traffic was closed off on the narrow coastal road that runs between CNIM and the port installations, the transportation frame containing the radial plate was delicately lifted and transported to a waiting area close to the Echion.
Early in the morning, operations resumed. Two cranes hoisted the 35-ton load onto the ship and carefully deposited it at the bottom of the cargo hold. Steel clamps were then welded directly onto the hold’s floor so that the load would be perfectly immobilized for the duration of the voyage to La Spezia.
By noon, the Echion was ready to sail. The Russian captain and his seven-man crew were optimistic: the weather report anticipated calm seas and clear sky for the 24 ahead — the time it would take to reach destination.
Click here to view a video of the operations.