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ITER NEWSLINE 292
Suppose you're building a Formula 1 car. You have the best engine ever, the best steering, braking and shock absorber systems, the best frame and a perfectly streamlined body. But now comes the hard part: in order to win the race, you need to have perfect integration of these different elements.
With ITER, it's the same. The ITER systems supporting the Tokamak will be spread out over several buildings. In order to produce a fusion plasma, the ultimate aim of ITER, all of these elements must cohabit and work in harmony, without clashes. The installation must run like a perfectly assembled and finely tuned race car.
"In all large installations or complex devices, integration is always key," says Design Integration Section Leader Jean-Jacques Cordier. "What is unique to ITER is the density and variance of the systems which implies a very strict management of the space available, not only in order to position the system components but also to allow for their future assembly and maintenance."
ITER is not only large and complex, it is also a nuclear installation "Safety rules are particularly stringent, and it is vital to observe and respect them during implementation. As ITER is the first fusion installation to be licensed as a nuclear installation, we need to propagate the safety requirements so that they become a culture that permeates every action we take."
Integration has always been a preoccupation within the ITER Organization. The Office for Central Integration and Engineering was established in June 2009; a Building Integration Task Force was set up two years later; and, recently, a team of Building Integration Area Managers was assembled and invested with redefined responsibilities and extended authority.
"Integration is something that is often a source of conflict," says Cordier, "and understandably so. It is sometimes hard for the person responsible for one system to accept that it has to be changed to make room for another system. 'Why should I modify my system when you can adapt the building?' And vice-versa ... you always hear these sorts of arguments."
The new area managers should facilitate a smoother implementation of the integration process in line with the ITER Project integrated schedule. Following two new recruitments there are now six area managers, all with strong experience in the design and construction of nuclear installations and large experimental devices.
Their redefined responsibilities are considerable. The area managers will assess the status of configuration and the functionality of all systems and structures in their area of jurisdiction (machine and Tokamak Pit, port cells, Tokamak Building, etc.) up to the delivery of the building and systems; they will make sure that space management requirements are satisfied; and they will take care of functional interfaces ... all within the requirements of the Preliminary Safety Report (Rapport préliminaire de sûreté, RPrS).
"The area managers have been chosen for their versatility, their capacity to mediate between conflicting parties and interests and their strong nuclear safety culture," stresses Cordier. "In the near future, when the equipment installation phase begins, area managers will act as full integration support to the now centralized construction management."
In addition to the six specialists already operational, four additional building integration engineers will join ITER early next year to assist them. The team will then be complete and ready to coordinate the integration of systems inside of the buildings and between buildings within the installation. With authority...
An important milestone was recently passed on the road to the fabrication of ITER's central solenoid by the US Domestic Agency, which has the responsibility for procuring the six modules that make up the central solenoid as well as the structure and the necessary assembly tooling. Since the signature of the Procurement Arrangement in March 2010 for this key component of the magnet system, the US ITER Project Office has been concentrating on the development of the design and the preparation of the manufacturing of the central solenoid modules.
Two years after chairing the Preliminary Design Review (PDR) in September 2011, Michel Huguet—former director of the Naka centre during ITER's early Engineering Design Activities phase—was given the responsibility of chairing the central solenoid's Final Design Review (FDR), which was held from 18 to 20 November at the US ITER Project Office with the attendance of magnet experts from Europe, Japan and the US.
It was a hard rush for the central solenoid team led by Wayne Reiersen (US) to provide all the required documentation in time for the review, including manufacturing drawings, analyses and R&D reports. Their high quality presentations gave an in-depth description of the design and of the supporting analyses and R&D and 3D prints allowed a better understanding of the geometry. A significant number of chits were issued by the review panel that will result in a few design modifications, but no category 1 chit, which should enable completion of the final design within a few months. Submission for review and approval of a revised 3D CAD model of the central solenoid is planned for February 2014.
In July 2011, General Atomics (San Diego, California) was awarded a contract to manufacture the six central solenoid modules. A visit of the manufacturing workshop located in Poway, California was organized after the design review on 21 November by John Smith, central solenoid project manager at General Atomics. The visitors saw the large manufacturing hall—nearly empty for the moment but ready to receive the components of the module manufacturing line in the next six months. The fabrication of a mockup module is scheduled to begin by the end of May 2014. Three dummy conductor lengths (see image) have already been delivered to Poway and will be used for the commissioning of the winding line. Manufacturing trials are also ongoing to address delicate processes like manufacture of helium inlets, joints or application of turn (see image) or ground insulation.
Keeping time with the production and delivery schedule for ITER's toroidal field magnets, Russian industry has shipped its second batch of toroidal field conductor for the year to the European winding facility in La Spezia, Italy.
After a first shipment of two 415-metre regular production lengths of niobium-tin (Nb3Sn) superconductor in June, it was the turn of three 760-metre production lengths to be loaded onto trucks on 25 November for the long voyage to Italy.
At the La Spezia facility, machines will unspool and straighten the conductor before shaping the continuous, 760-metre conductor lengths into a D-shaped double pancake. The pancakes will then be heat treated at over 650°C, electrically insulated and finally transferred into the grooves of the stainless steel radial plates to form a double pancake module.
The Russian Domestic Agency is responsible for 20 percent of toroidal field conductor procurement. Production is ongoing according to the schedule of the Procurement Arrangements. Nine 760-metre and two 415-metre spools have been manufactured and tested and are scheduled to be shipped to Europe at the beginning of next year.