• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.1
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• pp.31-39
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• 2013

Nuclear fuel can be damaged under unexpected circumstances in a nuclear reactor. Fuel rod failure can be occurred due to debris fretting or excessive hydriding or PCI (Pellet-to-clad Interaction) etc. It is important to identify the causes of such failed fuel rods for the safe operation of nuclear power plants. If a fuel rod failure occurs during the operation of a nuclear power plant, the coolant water is contaminated by leaked fission products, and in some case the power level of the plant may be lowered or the operation stopped. In addition, all spent fuels must be transferred to a dry storage. But failed fuel can not be transferred to a dry storage. Therefore, the purpose of this study is to develop a system which is capable of inspecting whether the spent fuel in the storage pool is failed or not. The sipping technology is to analyze the leakage of fission products in state of gas and liquid. The failed fuel inspection system with gamma analyzer has successfully demonstrated that the system is enough to find the failed fuel at Wolsong plant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.04a
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• pp.27-27
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• 1999

본 연구에서는 초음파 Immersion법을 이용하여 복합재 연소관내에 존재하는 결함을 검출하는 방법에 대하여 연구하였으며, 이를 위하여 FRP의 delamination, FRP-EPDM간의 미접착을 모사한 모의 결함 시편을 제작하여 시험하였다. 먼저 복합재료에 대한 초음파 시험방법을 최적화하기 위하여 가장 검출 감도가 좋은 탐촉자의 적용 주파수조건 및 물거리를 구하였으며, 이들 최적 조건으로 모의 결함 시편을 A, B, C-Scan하여 결함을 검출 분석하였다. 그리고 시험 자료를 바탕으로 데이터 값을 분석함으로써 복합재료에서의 음파 속도, 음향 임피던스, 반사율 및 투과율 등 복합재료의 초음파 특성을 산출하였으며, 동 시편에 대한 X-ray 필름을 촬영하여 그 결과를 초음파 시험 결과와 비교 분석하였다.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.2
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• pp.136-141
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• 2004

A torsional guided wave mode was applied to detect a crack in a pipe. An array of electromagnetic acoustic transduce. (EMAT that can generate and receive torsional guided ultrasound with the frequency of 200kHz was designed and fabricated for testing a pipe of 2.5 inch diameter Artificial notches with various depths were fabricated in a bent feeder pipe mock-up and the detectability was examined from the distance of 2m of the specimen. The axial notches with the depth of 5% of wall thickness were successfully detected by a torsional mode (T(0,1)) generated by the EMAT However, it was found that the depth of defects was not related to the signal amplitude.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1177-1185
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• 2022

The water and sewage system is an infrastructure that provides safe and clean water to people. In particular, since the water and sewage pipelines are buried underground, it is very difficult to detect system defects. For this reason, the diagnosis of pipelines is limited to post-defect detection, such as system diagnosis based on the images taken after taking pictures and videos with cameras and drones inside the pipelines. Therefore, real-time detection technology of pipelines is required. Recently, pipeline diagnosis technology using advanced equipment and artificial intelligence techniques is being developed, but AI-based defect detection technology requires a variety of learning data because the types and numbers of defect data affect the detection performance. Therefore, in this study, various defect scenarios are implemented using 3D printing model to improve the detection performance when detecting defects in pipelines. Afterwards, the collected images are performed to pre-processing such as classification according to the degree of risk and labeling of objects, and real-time defect detection is performed. The proposed technique can provide real-time feedback in the pipeline defect detection process, and it would be minimizing the possibility of missing diagnoses and improve the existing water and sewerage pipe diagnosis processing capability.

• Proceedings of the Korean Magnestics Society Conference
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• 1997.11a
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• pp.124-125
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• 1997

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.247-247
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.246-246
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• 1998

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.247-247
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• 2002

• Proceedings of the Korean Magnestics Society Conference
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• 2001.10a
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• pp.122-123
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• 2001

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.254-260
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• 2002

In this study, two types of mobile robotic systems using NDT (Non-destructive testing) method are developed for automatic diagnosis of the boiler tubes and large size pipelines. The developed mobile robots crawl the outer surface of the tubes or pipelines and detect in-pipe defects such as pinholes, cracks and thickness reduction by corrosion and/or erosion using EMAT (Electro-magnetic Acoustic Transducer). Automation of fault detection by means of mobile robotic systems for these large-scale structures helps to prevent significant troubles without danger of human beings under harmful environment.