Speaker
Kwen-Hee Hong
(Tokamak Engineering Department)
Description
ITER vacuum vessel (VV) is composed of 9 sectors, and each sector is completed through an assembly of 4 segments which are independently fabricated. Compared with Upper, Equatorial and Lower segment which have relatively large curvature in a 3 dimensional configuration, Inboard segment is the most difficult in aspect of a welding distortion control although it seems to be simply in fabrication due to relatively small change of curvature.
The mock-up of Inboard segment had been fabricated with a 3 m in a length and 40 degree in a width. At that time, even though the 34 mm of welding distortion was anticipated as a result of the analyses, it could be practically reduced up to 14.5 mm by the help of the special welding fixture developed to prevent welding distortion.
However, a welding distortion of a real Inboard segment is expected to be increased more than 2 times compared with the mock-up because its length is about 7 m which is longer than the mock-up. Therefore, it is very important to accurately measure a welding distortion according to a manufacturing sequence, and take a feedback control of a welding distortion in subsequent welding operation.
In this paper, the effect of a major welding operation on a welding distortion is evaluated for the fabrication of Inboard segment. For this evaluation, the 3 dimensional variations in the measurements of welding distortion of Inner shell were recoreded after the completion of welding of 18 keys, 48 flexible support housings, divertor support, and whole length of 3 poloidal ribs. These results will be used to design welding fixtures for the asembly of In-wall shield and Outer shell welding in order to control welding distortion within 20 mm which is an allowable requirement from ITER.
Co-authors
Byung-Ryul Roh Roh
(Hyundai Heavy Industries Co. Ltd., Ulsan, South Korea)
Chang-Ho Choi Choi
(ITER Organization, Saint Paul Lez Durance, France)
Chul-Kyu Park
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Gwang-Ho Kim
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Hak-Kun Kim
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Hyeon-Gon Lee
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Hyun-Soo Kim
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Jeong-Woo Sa
(ITER Organization, Saint Paul Lez Durance, France)
Kwen-Hee Hong
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Seong-Jo Jeong
(Hyundai Heavy Industries Co. Ltd., Ulsan, South Korea)
Sung-Wook Jin
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
Tae-Seok Kim
(Hyundai Heavy Industries Co. Ltd., Ulsan, South Korea)
Wooho Chung
(Tokamak Engineering Department, National Fusion Research Institute, Daejeon, South Korea)
