And toroidal direction of beveling of circular arc condition

摘要

PROBLEM TO BE SOLVED: To execute continuously remote automatic welding without interrupting a continuous work by welding between vacuum vessel sectors on an installation field of a nuclear fusion reactor and to execute high-quality welding for securing penetration soundness of a weld zone, and to improve productivity. SOLUTION: In this manufacturing method of a vacuum vessel 1 for a nuclear fusion reactor of a double-wall structure equipped with poroidal ribs on an inner wall, on an outer wall and between both walls, a curve-shaped dummy beveling 12 is formed beforehand on a splice plate 8 to be used when ring-shaped vacuum vessel sectors 2 obtained by dividing the vacuum vessel 1 for a nuclear fusion reactor by cutting it in plural round slices are welded on a field and connected. By forming beforehand the dummy beveling 12 on the splice plate 8, when executing field welding between the vacuum vessel sectors 2, automatic welding including a part of the dummy beveling 12 can be executed remotely, and the work can be executed continuously without requiring suspension of a welder or resetting of welding conditions.