
In its investigations to find the most optimal repair strategies for the thermal shield and vacuum vessel sectors, the ITER team worked for many months with experts from the ITER Domestic Agencies, professional organizations from the ITER Members, and research institutes such as CEA, CERN and professional welding institutes—as well as industrial partners to test its assumptions through mock-ups and trials. (Photo: January 2023)
One year ago, the first of nine vacuum vessel sector modules (#6) had been transferred in the Tokamak pit and two others (#7 and #8) were in preparation in sub-assembly tooling in the Assembly Hall, where the 440-tonne sectors were being matched with thermal shield panels and toroidal field coils.

Outboard segments of thermal shield await disassembly by contractor teams at one end of the Poloidal Field Coils Winding Facility on site. Two sets will be repaired at the premises of INOX India, and returned to ITER; the strategy for five other sets is being defined. (Photo: August 2023)
The vacuum vessel thermal shield, which confines the radiation heat load from the vessel and keeps it from being transferred to the magnets operating at 4.5K, is actively cooled by gaseous helium running through a network of cooling tubes welded to the panels. After "

The SIMIC/Ansaldo consortium will repair the non-conformities on sectors #6 and #7 while they are suspended in sector sub-assembly tooling in the Assembly Hall. The bevel regions will be re-worked through a combination of build-up (building up material through manual welding) and shaving (removing excess material through machining). (Photo: January 2023)
Dimensional non-conformities were found in the bevel (field joint) region of the three vacuum vessel sectors that have been delivered to ITER (#6, #7 and #8), with particularly severe variance against nominal geometry in sector #8. Left unrepaired, these non-conformities would compromise the access and operation of the bespoke automated welding tools planned for the in-pit welding of the sectors. The ITER Organization approach to repair is to re-work the bevels through a combination of building up material through manual welding and shaving excess material down through machining.