In an important manufacturing milestone for Russia and Europe, the first two 414-metre production lengths of conductor for poloidal field magnet #1 (PF1) have been successfully manufactured. On 5 August and 3 September, poloidal field cable manufactured in Russia underwent all of the phases of jacketing and compaction at the Criotec facility in Italy. Destined for spooling into the PF1 magnet, the jacketed conductor will be returned after necessary tests to the Efremov Institute in Saint Petersburg, where magnet manufacturing will take place. Criotec specialists have already begun welding activities on the metal jacket of a third conductor length for Russia prior to its compaction.
The first poloidal field conductor length for PF1 has already passed final tests in the vacuum chamber. The conductor will be delivered to the Efremov Institute by the end of 2014, where spooling activities for the first double pancake will start in 2015. Russia will complete the poloidal field conductors for PF1 by the end of 2016.
Superconducting Magnet Fast Discharge Units
At the Efremov Institute in Saint Petersburg, Russia, work is underway on the final design of the ITER fast discharge units—specialized components that are designed to protect the superconducting coils in the case of a sudden loss of superconductivity (quench).
Among them, the discharge units for ITER's powerful toroidal field coils will have the capacity to extract 41 GJ of stored energy. In the case of a quench, a set of mechanical circuit breakers will isolate the coils from the power supply and deviate the toroidal field current into discharge resistors that will dissipate the energy in about half a minute. With such an important role to play in the safety of the ITER installation, the components are classified as Protection Important Components (class 2) by the French nuclear safety authorities (ASN), a category that is subject to regulation and inspection.
On 24 July, two members of the ASN travelled to Saint Petersburg to perform an inspection of the work underway at the Efremov. The ASN inspectors were accompanied by two technical specialists from the French Institute of Radioprotection and Nuclear Safety (IRSN); representatives from the ITER Organization, the Russian Domestic Agency and the Efremov Institute were also present. It was the first ASN inspection carried out in Russia and also the first one for a component under the responsibility of the ITER Electrical Engineering Division.
Special attention was paid to the type tests, reliability tests and the qualification of the pirobreaker - the backup circuit breaker that must be available to operate in the case of the failure of the main circuit breaker. The pirobreaker conceived by the Efremov Institute over several years of R&D makes use of explosive charges to interrupt the current. During the inspection, the ASN delegation made a factory visit to examine a prototype.
At the conclusion of the inspection, the experts congratulated the Efremov Institute, the Russian Domestic Agency and the ITER Organization for the work underway on the fast discharge units. In its official inspection letter, ASN noted that, 'Other than a few improvements that could be made, the organization implemented by both the operator and the chain of suppliers involved in the Procurement Arrangement was efficient and rigorous.'
EU Forms Metals Research Consortium
The world's largest research consortium in the field of metals research and manufacturing is to be created by European industry in the form of Metallurgy Europe. The R&D program has recently been selected as a new Eureka Cluster and will bring together over 170 companies and laboratories from across 20 countries. Funding for the project has been stated as EUR 1 billion over seven years.
The European Powder Metallurgy Association and a number of other European organizations such as the European Space Agency (ESA), European Synchrotron Radiation Facility, the Institut Laue-Langevin and the Culham Centre for Fusion Energy are reported to be providing their expertise and innovation to this initiative.
Progress on Disruption Mitigation
US ITER researchers based at the Department of Energy's Oak Ridge National Laboratory (ORNL) are leading the development of a disruption mitigation system to reduce the effects of plasma disruptions on ITER. The US Domestic Agency for ITER signed a formal arrangement with the ITER Organization on 29 July for the work and during the week of 8 September the ITER Fuelling & Wall Conditioning Section leader, So Maruyama, paid a visit to Oak Ridge to assess US progress and plan for an upcoming design review of the ITER disruption mitigation technologies.
'I'm impressed,' said Maruyama after his visit to the disruption mitigation and pellet injection team at Oak Ridge. 'Only a year or two ago these were rough ideas. Now we have real prototypes that are functioning and being tested, such as the massive gas injection valve and the pellet selector.' 'We have a very conservative and flexible approach to disruption mitigation on ITER,' said Larry Baylor, a distinguished scientist in plasma technologies and applications at ORNL, 'with different locations for material to be injected, different types of material, and different response times. We are also designing the system in a way that will allow for evolution of the mitigation technology.'
Two approaches have been developed to help control plasma disruptions: massive gas injection and shattered pellet injection. Both deliver material to the plasma within milliseconds. By injecting material into the plasma, ITER operators will be able to manage plasma energy in a way that lessens thermal loads and mechanical stresses on the plasma-facing components of the machine. The injected material can also inhibit the formation of runaway electrons, which occur when electrons are accelerated from the electric field in the plasma during a disruption.
'This is essential technology development for ITER,' noted Maruyama. 'Oak Ridge is the expert on the pellet injector and has a long history of contributions to other machines such as JET, DIII-D and LHD.'
The development of technologies for ITER disruption mitigation benefits from physics input from around the world, including the ITER Organization, JET and Oak Ridge. The disruption mitigation design is also influenced by ITER experts in vacuum, tritium, cryogenics and port plug integration. The next major step for disruption mitigation is a system-level design review in November. Maruyama notes that 'this review will help us confirm where we are and what we've achieved, and help us try to narrow down options for the path forward.'
Blanket First Wall Prototypes
The European Domestic Agency has awarded contracts for the fabrication of three full-size prototypes of the blanket first wall, an important next step in the qualification of the first wall panels that follows in the steps of the successful manufacturing of a 1:6-scale semi-prototype earlier this year. Contracts were signed with Atmostat (ALCEN group, France), AREVA (France), and a consortium made up of AMEC (UK), Iberdrola (Spain) and MIB (Spain). Each of these companies is to manufacture a full-size prototype of a blanket first wall panel, as well as carry out specific industrialization studies for series production and present a cost and schedule assessment.
The choice of three companies was made by the European Domestic Agency to mitigate risk on these technically challenging components and preserve competition up to series production. Europe is responsible for procuring 215 normal heat flux first wall panels, while China and Russia are sharing the procurement of 225 enhanced heat flux panels. (A total of 440 first wall panels are needed for the ITER blanket.) These extremely high-tech components are made of 6- to 10-millimetre-thick beryllium tiles that are bonded with a copper alloy and 316L (N) stainless steel. Delivery of the full-scale prototypes is expected in early 2017.
Magnet Conductor Production
During the week of 6 October, the 12th Conductor Meeting took place in Kokura, Japan near the Wakamatsu ITER factory, where jacketing activities for ITER's toroidal field conductors and central solenoid conductors have been underway since 2010.
The Conductor Meeting is held semi-annually to reunite the actors involved in the procurement of conductors - from the ITER Organization, the six producing Domestic Agencies, and industrial manufacturers - for a review of progress.
Over 95 percent of toroidal field superconducting strand lengths and approximately 75 percent of toroidal field conductor unit lengths have been fabricated. As the procurement of toroidal field conductors nears completion, the focus of magnet activities is shifting to the next phase: the fabrication of 19 toroidal field coils (18 plus one spare). Three toroidal field conductors have been wound and heat treated in Japan and Europe.
Progress was also reported on central solenoid conductor procurement. Five central solenoid conductor unit lengths (approximately 10 percent of total needs) were fabricated and transferred from Japan to the USA in June 2014. These conductors will be wound for the lower module of the central solenoid coil stack (CS3L) in California.
Strand and conductor production for the poloidal field coils is also steadily advancing, with 18 unit lengths of poloidal field conductor manufactured to date.
The next Conductor Meeting will take place in March 2015 at the CRPP fusion institute in Switzerland. A final conductor meeting is foreseen in September 2015 at the ITER Organization.
Superconducting Strand Production
The European Domestic Agency has announced the realization of an important procurement milestone for ITER: the completion of Europe's share of the niobium-tin (Nb3Sn) superconducting strand required for the fabrication of ITER's powerful toroidal field coils.
Approximately 380 tons of Nb3Sn superconducting strand, or 'wire,' is required for ITER's toroidal field magnets. The wire is the key component that will allow the toroidal field magnets to reach 12 T and contribute to the confinement of the plasma. Each strand is less than 1 mm in diameter, and yet can sustain very high current when cooled down to 'superconducting' temperatures (-269 degrees Celsius).
Europe is the third ITER Domestic Agency, after Korea and Japan, to complete toroidal field strand production and all related ITER Organization control points. The more than 1,500 production units produced by the two manufacturers will be used to fabricate the cables for the European toroidal field coil cable-in-conduit conductor (CICC) lengths. Fifty percent of conductor unit lengths have already been produced and delivered to the Italian facility in charge of manufacturing the toroidal field coil winding packs. The remaining conductor lengths will be finalized in 2015.
New ITER Management Advisory Board
In order to improve project performance and in light of the ITER Project's specific managerial and cultural complexities, an External Management Advisory Board (EMAB) was established earlier this year. The members of the EMAB recently convened for their first meeting at ITER Headquarters.
The objective of the EMAB is to advise the ITER Organization's senior managers and the Director-General on enhancing project and safety culture, a challenging activity in the context of a mega international project with seven Members. Also, the Board is charged with assessing the practical implementation of the set of actions that was decided in response to the Management Assessment carried out in 2013. The Chair of this new entity is Jean Jacquinot, who also serves as scientific advisor to the Chairman of the French Alternative Energies and Atomic Energy Commission (CEA), Bernard Bigot.
Other Board members are Michael Tendler, professor at Sweden's Alfvén Laboratory (Royal Institute of Technology); Richard Hawryluk, head of the department of ITER and Tokamaks at the Princeton Plasma Physics Laboratory (US); Dhiraj Bora, director of the Institute for Plasma Research, IPR (India); and Yuanxi Wan, Academician of the Chinese Academy of Sciences and former Chairman of the ITER Science and Technology Advisory Committee (STAC). ITER's Colette Ricketts, of the System Management Section, is in charge of the secretariat.
'During our first meeting held on 20-21 October, we had a very fruitful discussion,' the Board members reported after the first meeting. 'We openly addressed issues such as the project's nuclear and safety culture, options for improved alignment between the ITER Organization and the Domestic Agencies, and last but not least the creation of the ITER Chief Executive Team, (ICET), formed to improve collaboration between all actors of the ITER Project.'
The Board will continue to address key ITER management issues at its next meeting, scheduled for 11-12 December 2014.
For further information on ITER progress, visit http://www.iter.org