Fitting the vacuum vessel sectors like a jacket, lining the inner wall of the cryostat, or covering the sides of vertical coil gravity supports, ITER's thermal shield panels act as a barrier preventing heat transfer to the ultra-cold superconducting magnets. Thermal shield panels cover a surface of approximately 4,000 m² and are actively cooled by way of a network of small-diameter pipes welded to their surface. In November 2021, tiny cracks were identified in the piping of three yet-uninstalled vacuum vessel thermal shield panels. Considering that the issue could be systemic, the decision was taken to remove and replace all cooling pipes (23 kilometres in total) and, in some cases, opt for a new attachment technique.
Source : Iter Newsline