ITER Diagnostics reached an important milestone in December 2021 when it concluded the last Procurement Arrangement of the diagnostics program. After signing a Procurement Arrangement with the Japanese Domestic Agency on 13 December 2021 for the design and manufacture of a lower port, the team could breathe a sigh of relief. With the last contract settled, all that remained was to carry out the work. "We manage the supply of components manufactured all over the world through these Procurement Arrangements (PAs)—and, for some diagnostics, through what we call complementary diagnostics PAs (CDPs)," explains Antonio Torralba Pinedo, in-kind management officer in the Project Control Office. "They bind the Domestic Agency to providing its in-kind contribution, as defined at the start of the project in the ITER Agreement. The Domestic Agency then involves industry by signing one or more contracts for procurement of the system." Each in-kind contribution constitutes a certain scope and value associated with a given system or component. This value is expressed in terms of an internal project currency, called the ITER Unit of Account (IUA). Procurement Arrangements are particularly challenging for diagnostics While diagnostic systems represent less than 5% of the total cost of the ITER Project, they account for more than 30% of the Procurement Arrangements. "Diagnostics are tremendously complicated because of the sheer number of systems," explains Torralba. "Over 100 diagnostics will be installed in the ITER machine, most of them in multiple locations." There may be a single diagnostic in three parts of the Tokamak—or in some cases, diagnostics with cables extending to thousands of locations inside the vacuum vessel. Even when the technologies are well understood, every one of the ITER systems is first-of-a-kind. While many of the diagnostics have already been used in smaller tokamaks, ITER requires systems that are either fully automated or remote controlled—and that can survive in a nuclear environment with huge heat and radiation loads. All systems have to be thoroughly qualified at all phases of their development, starting with the design and extending to commissioning. The assembly and testing of the different systems is also a challenge. After factory acceptance tests, most components are installed inside a port plug and tested again. Ultimately, the integrated port plugs are delivered to the ITER site, where they are finalized and commissioned along with other in-vessel diagnostics. A page is turned The technical specifications for ITER's full complement of in-kind diagnostic systems are contained in 54 PAs/CDPs representing 66 projects. Concluding the Arrangements, which involved all seven Domestic Agencies, was a big achievement. Before each signature, the conceptual designs of the systems had to be completed—no small feat, given the leading-edge technology involved. "What's more, each Domestic Agency has its own unique set of internal processes," explains Torralba. "There was quite a bit of negotiation to arrive at a common understanding for every signature—a reflection of the unique cultures and practices of the ITER Members." The first diagnostic Procurement Arrangement was signed in June 2011, the first of six that year. In subsequent years, up to 13 Procurement Arrangements were signed per year—a far higher rate than any other group of the ITER Project. "Unlike other groups, which have a small number of high-value Procurement Arrangements, diagnostics is characterized by many smaller value items," explains Torralba. "Managing the specifications for all these technologies, often in parallel, and making sure the different elements come together on time was very complicated, and required flexibility and coordination." With the last diagnostic Procurement Arrangement now signed and the Domestic Agencies committed, Torralba is looking forward to the future. "We can now focus all our effort on getting the systems built and integrated."

The distance was short but the challenge daunting: on Thursday last week, the first section of the plasma chamber was lifted 50 centimetres above its supports. What made this first-of-a-kind operation particularly delicate was the nature of the load (a 1,380-tonne, 18-metre-tall assembly) and the extreme precision its handling required. A restricted area most of the time, the space at the base of the giant SSAT2 pre-assembly tool was exceptionally crowded. Specialists sat facing rows of computers, checking the numbers and graphs flashing on the screens. Crane operators delicately manoeuvred the joysticks on their control boxes. Once all movement had ceased, metrology experts pointed laser beams all over the steely surface of the component, measuring the most minute dimensional deviations to ensure that they remained within tolerance. The "pre-lift" operation on Thursday 5 May was only the first sequence of the long-expected installation of the first vacuum vessel module in the assembly pit. In both height and distance it represented only a fraction of what the actual operation, scheduled in the coming days, will require. But for the teams involved, it was an indispensable step—permitting the thorough testing of every instrument involved before the big move to come.  Click here to watch a short video of the pre-lift operation.

The toroidal field coil procurement effort has been one of the longest of the ITER program, initiated by Procurement Arrangements signed in 2007 and 2008. Manufacturing is nearly completed. Six Domestic Agencies took part in the procurement of over 100,000 km of niobium-tin superconducting strand (China, Europe, Japan, Korea, Russia and the United States); now, Europe and Japan are completing the fabrication and testing of 18 toroidal field coils plus one spare. Each coil is made up of a superconducting winding pack and surrounding stainless steel coil case. Thirteen toroidal field coils have already arrived on site including coil #17 (TF17), delivered last Friday 6 May by the European Domestic Agency. Ninety-nine percent of the total manufacturing scope has been completed. Once at ITER, the toroidal field coils are either stored or moved to a staging area to be prepared for handling. The teams carry out a variety of mechanical preparatory activities such as the welding of cooling pipes and the attachment of clamps/interfaces. When their turn comes in the assembly sequence, the D-shaped coils are associated (by pair) with one vacuum vessel sector. Coils TF12 and TF13, from Japan, were the first to be assembled with vacuum vessel sector #6 on specialized tooling in the Assembly Hall, forming the first sub-section of the ITER vacuum vessel. (See related article in this issue.) A second sub-assembly operation is underway that will associate European coil TF9 and Japanese coil TF8 with vacuum vessel sector #1(7). The delivery of six more coils—three from Europe and three from Japan—will complete the toroidal field coil procurement program.

Work is progressing on the ITER Control Building, ergonomically designed for the 60 to 80 operators, engineers and researchers who will call it home. Newsline paid a quick visit to the construction site last week. As the heart and vital organs of ITER will beat and pulse in the Tokamak Complex and in the various facilities spread over the installation's platform, the brain that commands them will occupy a 3,500-square-metre, three-storey structure providing space for the control and server rooms, offices, meeting rooms and support facilities. The ITER Control Building will be the daily work environment for the operators, researchers, and engineers running ITER physics experiments or the routine 24-hour operation and control functions of the machine and plant. A good deal of planning has gone into the design of the different spaces to create a "liveable" environment—one that is conducive to focus and concentration, yet that also encourages interaction and communication between the teams. Lighting, materials, acoustics, temperature, airflow, noise levels, the colour and arrangement of displays, seating and furniture, rest areas ... all of these elements have been carefully studied and organized. The main control room will be staffed on a 24-hour-per-day, continuous basis for the operational life of the ITER facility. It will be a large chamber with an open floor plan, seven-metre ceilings, natural light, large-screen displays, desks grouped by task or unit, and a glass-walled visitor gallery. A second, backup control room will be housed in a seismically protected nuclear building to ensure plant functionality in all circumstances. See the gallery below for the most recent photos of construction.