Close to two years have passed since vacuum vessel assembly was halted when defects were identified in the ITER tokamak's vacuum vessel sectors and thermal shield. Following months of analysis, strategy definition and contractor selection, repair operations began in earnest in the first quarter of 2024. Last week, visitors to the Assembly Hall were greeted by a comforting vision: in one of the massive handling tools (SSAT1), vacuum vessel #7 is now free of the dense scaffolding that had kept it hidden for the better part of the year, its bevels restored to their nominal geometry. Attached to one of the tool's rotating wings, one of the sector's thermal shield panels, just back from repair in India, stands at a 90-degree angle. Vacuum vessel assembly is back in the starting blocks. As assembly operations proceed on vacuum vessel sector #7, which will lead to the completion of a "sector module" ready for installation in the tokamak pit, repairs are also progressing on the two other sectors present on the ITER site. In the second handling tool (SSAT2) metal build-up is completed on sector #6 and machining should be finalized by mid-November. In the former Cryostat Workshop, vacuum vessel sector #8—the most affected by non-conformities of the three—is being repaired in horizontal position, with only one side of the component accessible at a time. On the "visible" side, manual metal build-up is now complete and mechanized build-up has started. Once the first side has been repaired, the 440-tonne component will need to be "flipped" and the sequence of operations will be repeated on the other side. The forecast date for completion is July 2025. (See a detailed report here.) Assembly operations can now proceed on vacuum vessel sector #7 (pictured). In the twin handling tool, repair works on sector #6 should be completed by November 2024. In the former Cryostat Workshop, repairing both sides of vacuum vessel sector #8 will require flipping the 440-tonne component. The forecast date for completion is July 2025. Of the nine sets of thermal shields that wrap the nine vacuum vessel sectors like a tight-fitting jacket, seven were sent for repairsto INOX-CVA in India. Two have returned, fully repaired, to ITER. Two extra sets are being completely remanufactured at SamHong Heavy Machinery in Korea. Vacuum vessel thermal shield panels were not the only components susceptible to the same, millimetre-deep cracks in the cooling pipes that had been detected in 2022. As a consequence the cryostat thermal shield and the panels protecting the vertical coil gravity supports—both already installed in the tokamak pit—are concerned by the replacement of the cooling pipe network. In 2023, the 18 gravity support panels were removed and sent for repair to a contractor near Lyon, France. The lower cryostat thermal shield, which was installed in January 2021, presented a more daunting challenge. Due to space and cleanliness constraints inside the assembly pit, removing and re-welding cooling pipes has been ruled out; instead, a new set of piping will be clamped to the component's surface. As for the other sections of the cryostat thermal shield—support, equatorial and upper, all delivered and stored—the options are still open: either repair or remanufacturing.

What is simple and commonplace in the ordinary world, like connecting an electrical device to a power source, often takes on extraordinary dimension at ITER. Whereas in most daily-life circumstances, copper cables ranging in diameter from a few millimetres to the thickness of an arm are sufficient to transport electrical current at the appropriate intensity, some components in ITER are so unique that they require a highly sophisticated, oversized electricity distribution system. Originating in the twin Magnet Power Conversion buildings and spanning the worksite's "central boulevard" by way of two 50-metre-long bridges, a dense network (5 km) of steel-jacketed, actively cooled aluminum bars protected by canary-yellow casing snakes into the Tokamak Complex to deliver high-intensity DC current to the machine's magnets. The thickest of these "busbars,", thicker than a train rail, are dimensioned to carry up to 70 kiloamperes (kA)—7,000 times more than a heavy-duty electrical cable. Busbar installation began in 2019 and is now 55 percent complete. As space in the galleries inside the Tokamak Complex is getting more constrained by the day, busbar transport and positioning procedures now require 3D modelling and simulations. The final leg of the transfer was smooth but no less delicate as the busbar had to pass over three massive auxiliary cold boxes with limited overhead clearance. On Wednesday 4 September, the teams installed a 1.5-tonne boomerang-shaped busbar destined for the central solenoid feeder system. From the beginning, the operation presented some unique challenges. "Due to the number of obstacles between the cargo lift (the system that delivers loads to the different levels of the building) and the destination, we had to find an alternate path to deliver the component," explains Arantxa Iniesta-Mancillas, Construction Manager for the DC busbars and most systems feeding power to the reactor. The busbar (4.8 m x 5.3 m) was moved through the Cleaning Facility to the Assembly Hall by means of rolling carts, then lifted by overhead crane over the wall and deposited in a wide delivery area in the Tokamak Building. The final leg of the transfer was smooth but no less delicate as the busbar had to pass over three massive auxiliary cold boxes with limited overhead clearance. Originating in the twin Magnet Power Conversion Buildings, busbars will reach the Tokamak Building by way of two 50-metre-long ''bridges'' spanning the construction platform's main boulevard. The bridges are now in place and the installation of electrical equipment is ongoing. This last phase was made possible by the availability of a smaller overhead crane, recently installed for maintenance operations to the cryogenic system. "Without the overhead crane, we would have had to dismantle all the scaffolding around the area in order to clear a path for the busbar, which would have had a major impact on other work fronts and contractors." Two other similar, boomerang-shaped busbars need to be installed in the same area and connected to the busbar lines crossing the Diagnostics Building. Approximately 70% of the busbar lengths expected from ITER Russia (402 out of 570) have been received on site.

A yearly tradition in the ITER community for more than a decade now, the ITER Games offer a pleasant way to reconnect among colleagues and neighbours after the summer recess. On Saturday 14 September, just over 700 people took part. Tennis, kayak, mountain biking, trail running, football, the Provencal boule sport of pétanque, and (new this year as a demonstration) handball—there was something for every athlete at the 11th ITER Games in Vinon-sur-Verdon on Saturday 14 September. The games are organized for the staff and contractors working on the ITER project, their families, and local sportsmen and women from the towns of Vinon-sur-Verdon and Saint Paul-lez-Durance. Games for childen, a bouncy castle, lunch on the village square, an awards ceremony and live music rounded out the day's athletic program. The ITER Games associations thank the ITER Organization, Agence Iter France, the neighboring towns, and corporate sponsors Apave, Assytem, Daher, Engage, Vinci, Ferrovial, Razel-Bec, Dalkia and MOMENTUM for their support.

A group of fusion researchers has left Padua, Italy, for an 800-kilometre bike trip to the ITER site. Their goal? To share information about fusion energy research and career opportunities in the field with the public they meet along the way. On 10 September, after a small send-off ceremony, twenty researchers and technicians from Consorzio RFX and the Fusion Research Center of the University of Padua set off on a two-wheeled adventure—biking from Italy to France to spread the message about fusion. Along the way they will be joined by colleagues from the CNR Institute for Plasma Science and Technology in Milan, the ENEA Fusion Center in Frascati, and scientists from the ITER Organization. Events to meet the public have been scheduled in Piacenza, Pavia and Marseille, and on Thursday 19 September the group will arrive at the ITER site. See the route they are taking here.