Studies on the fabrication of T-branches for ITER thermal shield manifold pipes

Abstract

Abstract The ITER thermal shield (TS) minimizes radiation heat loads from the vacuum vessel and the cryostat to the superconducting magnets. It is actively cooled by pressurized Helium gas. The TS Manifold (TSM) provides Helium coolant from the cold valve box (CVB) to the cooling tubes on the TS panels. Among the manufacturing of TSM, the most challenging issue is fabrication of pipe T-branches which is consisted of drilling, T-extrusion, surface milling and orbital welding. After the orbital welding the welded areas are tested by visual and x-ray examinations. Functional tests are carried out by cold shock and pressure and vacuum leak testing. This paper introduces the procedures for the fabrication and examinations for the T-Branch of the TSM.