Speaker
Yu-Gyeong Kim
(National Fusion Research Institute)
Description
Korea has been manufacturing two vacuum vessels of ITER and main jointing method to in-wall shield assemblies is welding. Though in-wall shield ribs holding neutron shielding blocks should sustain various design loads such as electro-magnetic forces, earthquake and their own weights, as a part of the assembly, in-service inspections are hardly possible because they are installed between double-wall of the vacuum vessel.
In this study, a series of linear elastic fracture mechanics assessment was carried out to examine structural integrity of the in-wall shield ribs for supplement of current design approach. Two kinds of idealized cracks were assumed and conservative assessment conditions were selected from relevant design documents. Particularly, fatigue crack growth evaluation was performed according to well-known fitness-for-service codes and their validity was checked via finite element analyses.
As a result, it was proven that the in-wall shield ribs had sufficient structural margins even if fracture mechanics was applied to the plausible crack under typical loading conditions. Besides, effects of applicable codes as well as artificial crack shapes, sizes and orientations were evaluated quantitatively. The detailed assessment method could be used for subsequent structural integrity assessment of other ITER component manufactured by the welding.
Co-authors
Yoon-Suk Chang
(Department of Nuclear Engineering, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, South Korea)
Yu-Gyeong Kim
(National Fusion Research Institute, 169-148, Gwahak-ro, Yuseong-gu, Daejeon, South Korea)
