TY - JOUR
T1 - Evaluation of the functional acceptability of the ITER vacuum vessel
AU - Moon, Hokyu
AU - Park, Soo Hyeon
AU - Kim, Hyun Soo
AU - Kim, Beom Seok
N1 - Publisher Copyright:
© 2022 The Author(s). Published by IOP Publishing Ltd.
PY - 2023/1
Y1 - 2023/1
N2 - The International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is one of the critical components of the ITER tokamak fusion reactor. The first sector of the ITER VV was delivered to ITER Organization in 2020, and it is ready to assemble into the tokamak system. After manufacturing the ITER VV, an evaluation should ensure that the components are designed and manufactured to meet the functional requirements, such as vacuum leak tightness and structural integrity. The factory acceptance test (FAT) is essential for confirming acceptance in engineering and manufacturing. This paper introduces the engineering process and technical method of the FAT, which is applied explicitly to the first-of-a-kind ITER VV. We establish a visual inspection, pre-pumping assessment, pressure test, helium (vacuum) leak test, and final dimensional inspection for the FAT. The visual inspection revealed no blockages in the cooling channels of the double walls. The pre-pumping assessment conducted to check the vacuum level and residual gas condition, concluded that the inside of the VV was flawless and thus met the leak test requirements of 1 × 10−8 Pa m3 s−1. We confirmed no leakage or deformation through the pressure test under reduced pressure. The helium leak test demonstrated engineering soundness with leak tightness of 6.08 × 10−9 Pa m3 s−1, which is more stringent than the allowable limit. Furthermore, three-dimensional metrology was utilized to determine the as-built dimensions of the manufactured sector. Due to unavoidable weld deformation and tight tolerances, the as-built result does not perfectly meet the assigned tolerance level. Nevertheless, it can be considered as advanced information for assembly with in-vessel components and other sectors. Based on the conformance and suitability of the suggested FAT for the first ITER VV sector, we will determine the acceptability of the upcoming VV sectors, which will be manufactured and delivered by Korea shortly.
AB - The International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is one of the critical components of the ITER tokamak fusion reactor. The first sector of the ITER VV was delivered to ITER Organization in 2020, and it is ready to assemble into the tokamak system. After manufacturing the ITER VV, an evaluation should ensure that the components are designed and manufactured to meet the functional requirements, such as vacuum leak tightness and structural integrity. The factory acceptance test (FAT) is essential for confirming acceptance in engineering and manufacturing. This paper introduces the engineering process and technical method of the FAT, which is applied explicitly to the first-of-a-kind ITER VV. We establish a visual inspection, pre-pumping assessment, pressure test, helium (vacuum) leak test, and final dimensional inspection for the FAT. The visual inspection revealed no blockages in the cooling channels of the double walls. The pre-pumping assessment conducted to check the vacuum level and residual gas condition, concluded that the inside of the VV was flawless and thus met the leak test requirements of 1 × 10−8 Pa m3 s−1. We confirmed no leakage or deformation through the pressure test under reduced pressure. The helium leak test demonstrated engineering soundness with leak tightness of 6.08 × 10−9 Pa m3 s−1, which is more stringent than the allowable limit. Furthermore, three-dimensional metrology was utilized to determine the as-built dimensions of the manufactured sector. Due to unavoidable weld deformation and tight tolerances, the as-built result does not perfectly meet the assigned tolerance level. Nevertheless, it can be considered as advanced information for assembly with in-vessel components and other sectors. Based on the conformance and suitability of the suggested FAT for the first ITER VV sector, we will determine the acceptability of the upcoming VV sectors, which will be manufactured and delivered by Korea shortly.
KW - factory acceptance test
KW - functional acceptance
KW - ITER
KW - tokamak fusion reactor
KW - vacuum vessel
UR - http://www.scopus.com/inward/record.url?scp=85143599299&partnerID=8YFLogxK
U2 - 10.1088/1741-4326/aca1d0
DO - 10.1088/1741-4326/aca1d0
M3 - Article
AN - SCOPUS:85143599299
SN - 0029-5515
VL - 63
JO - Nuclear Fusion
JF - Nuclear Fusion
IS - 1
M1 - 016003
ER -
