A public-private testing partnership certified that ITER's vacuum components can withstand major seismic events. Making sure the ITER tokamak will be safe in the event of an earthquake means components such as flanges, pumps, and valves for the vacuum system must meet exacting design standards and undergo extensive analysis using computer modelling. And once all that is done? "Then we get to shake the bejeebers out of things," says Eamonn Quinn, the Vacuum Mechanical Engineer at ITER who oversees the security of the components. Seismic testing is a crucial step in the construction of a nuclear facility but at ITER it takes on special importance because there are so many first-of-kind components and the safety standards being developed will likely inform future fusion regulations. The vacuum team at ITER is currently qualifying more than 70 different types of metal valves to ensure they remain secure during an earthquake. While nuclear fusion doesn't carry the same risk of a runaway reaction as a traditional fission reactor, a valve still needs to function during crisis situations to prevent tritium or other matter from escaping the tokamak. This means valves go through high-intensity simulations on shaker tables to guarantee they close or open correctly and continue to serve as a confinement barrier during a seismic event. "The qualification process is sensitive because earthquake conditions need to be replicated, which means recreating the precise vibrations, heat, and mechanical load that's expected in the particular location the component is going to be used," explains Eamonn. "The lead-up to one test can be many months; it's a mammoth task." Part of this mammoth task was facilitated by a public-private partnership that ITER formed with Element, which is one of the world leaders for testing and certification, and the University of Bristol, which has one of the larger shaker table facilities in Europe. A DN 160 all-metal vacuum valve on the shaker table. In the background, from left to right: David Laugier, Eamonn Quinn and Graeme Vine from ITER, and Chris Stone from Element. Much of the testing done by Element involves the aeronautics sector and simulating fight conditions for parts that will be used in airplanes. However, the company also does a wide range of other testing, such as recreating desert environments to see how machines resist dust storms or simulating cold and vibrations to check if pregnancy tests can handle low-temperature transport. It was precisely this type of flexibility that made a success of the partnership between ITER and Element because they were able to reliably recreate the conditions the valve would face in the Tokamak Building. But before the valves found their way to a seismic shaking table in Bristol, they went through a rigorous testing process. First, the representative sample of the valves produced by the manufacturer VAT went through operational and vacuum testing before being shipped. Once at ITER, valve cycling and helium leak testing was conducted to make sure the valve met vacuum protocols. After this, it was transported to the University of Bristol, where Element has an agreement to rent time on the university's shaker tables—allowing doctoral students to gain real-world engineering experience by observing testing and certification such as that done for ITER. ITER personnel were always on-site for the seismic testing in Bristol to provide the vacuum and tokamak expertise. Prior to each test, the team at Element programmed the three-metre-square table based on the metrics provided by ITER. Depending on where in the Tokamak Building the valve will be positioned, the valve was shaken to IEEE standards based on different possible conditions: SL-1 (light earthquake), SL-2 (medium earthquake), or SL-3 (extreme earthquakes that are far beyond any projected seismic activity in the south of France where ITER is located). While the shaking during much of the testing was similar to driving along a bumpy country road, at its peak it reached a g-force of 8g, which was equivalent to the vibrations felt by a rocket during re-entry to the Earth's atmosphere. For each test, the valve was filled with helium and wrapped in a vacuum bag to see if structural breaches occurred during shaking that would allow the gas to escape. Then, heating blankets were added to simulate the temperature of the tokamak and a mechanical rig was used to replicate the forces that would be on the valve when it will be in use. Once all this was in place, a technician "drove" the table, which means it was shaken along three axes to create the precise ground accelerations of an earthquake. "The tests were quite spectacular, especially for the SL-3 testing," says Graeme Vine, an ITER vacuum engineer who was involved in the testing. When a valve passed these tests, it became qualified for use at ITER. The lead time to manufacture large valves can be as much as 15 months, which adds to the long journey from design to having a qualified component in hand. Chris Stone, the department manager for the seismic testing at Element, has been part of valve testing for the last six years. He says the ITER work is some of the most complex testing the company has done, but it is also among the most rewarding. "ITER is a public domain project, so there is a great philosophy of sharing information with the aim of doing the best job possible," says Chris. "And from an engineering point of view, being part of a project that has the majority of the world trying to do something that will make the whole place better, you can't get much better than that, can you?" See what a shake experiment for ITER looks like on YouTube here.

Like a circle of giant syringes all pointing inward, the feeders transport and deliver the essentials to the 10,000-tonne ITER magnet system—that is, electrical power and cooling fluids. Twenty-one feeders, each dedicated to a specific coil or pair of coils¹ are installed in the gallery at the second basement level (B2) of the Tokamak Building; ten others are located five floors above at the L3 level. All have been provided by China. Installation of the massive, maddeningly complex systems, began in November 2018 with the insertion of a captive "cryostat feedthrough"—the 10-metre-long section of a feeder section—at the bottom of the Tokamak Pit. Over the ensuing years the main elements that constitute a feeder were progressively installed in the galleries of the Tokamak Building. At the B2 level, 16 coil terminal boxes the size and weight of a city bus, and 18 cryostat feedthroughs that pass through the bioshield and cryostat to be connected to the coils are now fully installed and welded. At the L3 level, 6 coil terminal boxes and 8 cryostat feedthrough have been lifted and placed in long-term temporary positions, pending the insertion of the cryostat's upper cylinder. Of 21 feeders installed in galleries at the B2 level of the Tokamak Building, two accommodate high and low-voltage instrumentation cables and hardware. Ten other feeders are located five floors overhead, at the L3 level. One of the most delicate operations in the installation process is the creation of the superconducting joints² that provide electrical connections between the busbar at the exit of the coil terminal boxes and those at the entrance to the cryostat feedthroughs. Teams of highly skilled workers, having qualified via robust training program, are presently working on joint assembly at the B2 level of the Tokamak Building. In the image above, workers from the CNPE consortium are finalizing the joints on the feeder connected to the lowest central solenoid module (CS2L). Their job consists in positioning high-pressure fiberglass panels around the finalized joint in order to form a "hard shell," or mold, into which epoxy resin will be poured to ensure electrical insulation. As a joint's electrical performance can only truly be put to the test at the ITER operating temperature of 4 K (minus 269 °C) and operating current (up to 70 kA)—and these conditions will only be reached when the machine is commissioned—the quality of the work performed is of paramount importance for the project. ¹Of the 31 feeders to be installed (21 at lower level, 10 at upper level), two are exclusively dedicated to instrumentation signals and three to the cooling of coil structures. All others carry current and coolant to magnets. ²The solutions that were developed for the joints bring their electrical resistance to an extremely low value—in the nano-ohm (nΩ) range. Despite this tiny amount of resistance and resulting small amount of heat generated, they can still be called "superconducting." See also: H. Kim et al., "Progress on First-of-a-Kind Feeder Superconducting Machine Joints and Surrounding Structure Assembly in ITER Magnet System," in IEEE Transactions on Applied Superconductivity, vol. 34, no. 5, pp. 1-4, Aug. 2024, Art no. 4205104, doi: 10.1109/TASC.2024.3366158. The criticality of the superconducting feeder joints stems from the fact that they can only be truly tested once the machine is up and running. Hence the exceptionnaly demanding qualification programs for the technicians who realize joint assemblies. As a joint's electrical performance can only truly be put to the test at the ITER operating temperature of 4 K (minus 269 °C) and operating current (up to 70 kA)—and these conditions will only be reached when the machine is commissioned—the quality of the work performed is of paramount importance for the project. ¹Of the 31 feeders to be installed (21 at lower level, 10 at upper level), two are exclusively dedicated to instrumentation signals and three to the cooling of coil structures. All others carry current and coolant to magnets. ²The solutions that were developed for the joints bring their electrical resistance to an extremely low value—in the nano-ohm (nΩ) range. Despite this tiny amount of resistance and resulting small amount of heat generated, they can still be called "superconducting." See also: H. Kim et al., "Progress on First-of-a-Kind Feeder Superconducting Machine Joints and Surrounding Structure Assembly in ITER Magnet System," in IEEE Transactions on Applied Superconductivity, vol. 34, no. 5, pp. 1-4, Aug. 2024, Art no. 4205104, doi: 10.1109/TASC.2024.3366158.

It's FAB season at ITER. Like every year since 2008, the Financial Audit Board (FAB) will proceed with a meticulous audit of the project's finances, sifting through thousands of documents, crunching numbers, conducting interviews and requesting external evidence such as vendor invoices, salary slips and bank documents to confirm revenue, expenditures and other financial data. The month-long process—two weeks of preparatory work by PRE-FAB junior auditors, followed by another two weeks of in-depth analysis by senior FAB auditors representing the ITER Members—aims at ensuring that the Project Resource Management Regulations are observed and that the ITER Council can rely on the numbers that are provided.

The European Domestic Agency Fusion for Energy (F4E) is calling for fusion technology transfer demonstrator proposals before 30 July 2024.  Open to European companies and organizations, the call aims to support projects that propose to take fusion breakthroughs into new markets. Proposals will be evaluated on the feasibility of the demonstrator project, its innovation potential, and socio-economic impact. Proposals should describe the further use or adaptation of a technology or skill developed under F4E activities into a new product or service in non-fusion applications. The Call invites entities from the fusion sector (F4E's Industrial Partners) and the non-fusion sector to submit proposals. The selected project will be funded with EUR 50,000. See this webpage for a description of the Call and this website to apply.