Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method
To ensure the integrity and safety of steam generator tubes in nuclear power plants, eddy-current testing is periodically employed. Because steam generators are equipped with thousands of thin-walled tubes, the eddy current is tested using a bobbin probe that can be used at high speed. Steam generat...
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MDPI AG
2021-01-01
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| author | Sebeom Oh Gahyun Choi Deokhyun Lee Myungsik Choi Kyungmo Kim |
| author_facet | Sebeom Oh Gahyun Choi Deokhyun Lee Myungsik Choi Kyungmo Kim |
| author_sort | Sebeom Oh |
| collection | DOAJ |
| description | To ensure the integrity and safety of steam generator tubes in nuclear power plants, eddy-current testing is periodically employed. Because steam generators are equipped with thousands of thin-walled tubes, the eddy current is tested using a bobbin probe that can be used at high speed. Steam generator heat pipes in nuclear power plants have different sizes and shapes depending on their row number. In particular, heat pipes in the first row are located inside the steam generator and are of the U-bend type because the radius of the curved pipe is the smallest. A steam generator heat pipe has a thickness of about 1 mm, so a geometrical cross-sectional area change may occur due to residual stress when manufacturing the curved pipe. It is difficult to determine an exact shape because the change in cross-sectional area generated during the manufacturing process varies depending on the position of the pipe and the distortion rate. During eddy-current testing (ECT), to ensure the integrity and safety of the steam generator tubes, the shape change of the bend may cause a noise signal, making it difficult to evaluate defects in the pipe. However, the noise signals generated in this situation are difficult to analyze in a real measurement environment, and difficult to verify by producing a mock-up, which complicates distinguishing a noise signal from a defective signal. To solve this problem, various noise signals were obtained using the electromagnetic analysis method of COMSOL Multiphysics, a commercial program based on numerical analysis of the finite element method, to simulate the environment, including the change in cross-sectional area of the heat pipe. When compared to the actual measurement signal, the accuracy of the simulations improved, and various types of noise signals were detected, which may be helpful for accurate evaluations of defects during actual inspections. |
| first_indexed | 2024-03-09T05:00:51Z |
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| id | doaj.art-31d91480b618431cb07810d1be8e2692 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T05:00:51Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-31d91480b618431cb07810d1be8e26922023-12-03T12:59:40ZengMDPI AGApplied Sciences2076-34172021-01-0111269610.3390/app11020696Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element MethodSebeom Oh0Gahyun Choi1Deokhyun Lee2Myungsik Choi3Kyungmo Kim4Materials Safety Technology Development Division, Korea Atomic Energy Research Institute, 111 Daedeok-daero 989Beon-Gil, Yuseong-gu, Daejeon 34057, KoreaR&D Institute, BEES Inc., Daejeon Business Agency, 96 Gajeongbukro, Yuseong-gu, Daejeon 34111, KoreaMaterials Safety Technology Development Division, Korea Atomic Energy Research Institute, 111 Daedeok-daero 989Beon-Gil, Yuseong-gu, Daejeon 34057, KoreaMaterials Safety Technology Development Division, Korea Atomic Energy Research Institute, 111 Daedeok-daero 989Beon-Gil, Yuseong-gu, Daejeon 34057, KoreaMaterials Safety Technology Development Division, Korea Atomic Energy Research Institute, 111 Daedeok-daero 989Beon-Gil, Yuseong-gu, Daejeon 34057, KoreaTo ensure the integrity and safety of steam generator tubes in nuclear power plants, eddy-current testing is periodically employed. Because steam generators are equipped with thousands of thin-walled tubes, the eddy current is tested using a bobbin probe that can be used at high speed. Steam generator heat pipes in nuclear power plants have different sizes and shapes depending on their row number. In particular, heat pipes in the first row are located inside the steam generator and are of the U-bend type because the radius of the curved pipe is the smallest. A steam generator heat pipe has a thickness of about 1 mm, so a geometrical cross-sectional area change may occur due to residual stress when manufacturing the curved pipe. It is difficult to determine an exact shape because the change in cross-sectional area generated during the manufacturing process varies depending on the position of the pipe and the distortion rate. During eddy-current testing (ECT), to ensure the integrity and safety of the steam generator tubes, the shape change of the bend may cause a noise signal, making it difficult to evaluate defects in the pipe. However, the noise signals generated in this situation are difficult to analyze in a real measurement environment, and difficult to verify by producing a mock-up, which complicates distinguishing a noise signal from a defective signal. To solve this problem, various noise signals were obtained using the electromagnetic analysis method of COMSOL Multiphysics, a commercial program based on numerical analysis of the finite element method, to simulate the environment, including the change in cross-sectional area of the heat pipe. When compared to the actual measurement signal, the accuracy of the simulations improved, and various types of noise signals were detected, which may be helpful for accurate evaluations of defects during actual inspections.https://www.mdpi.com/2076-3417/11/2/696steam generator tubeeddy-current testingfinite element methodmodelingcomputed tomography |
| spellingShingle | Sebeom Oh Gahyun Choi Deokhyun Lee Myungsik Choi Kyungmo Kim Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method Applied Sciences steam generator tube eddy-current testing finite element method modeling computed tomography |
| title | Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method |
| title_full | Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method |
| title_fullStr | Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method |
| title_full_unstemmed | Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method |
| title_short | Analysis of Eddy-Current Probe Signals in Steam Generator U-Bend Tubes Using the Finite Element Method |
| title_sort | analysis of eddy current probe signals in steam generator u bend tubes using the finite element method |
| topic | steam generator tube eddy-current testing finite element method modeling computed tomography |
| url | https://www.mdpi.com/2076-3417/11/2/696 |
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