• Title/Summary/Keyword: nuclear testing

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A Basic Study on Eddy Current Testing of End-Cap Welds (봉단 용접부 와전류탐상의 기초적인 연구)

  • Suh, D.M.;Sim, K.S.;Kwon, W.J.;Kim, J.H.;Park, C.H.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.18 no.2
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    • pp.85-91
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    • 1998
  • In nuclear fuel manufacturing process, end-closure welding has long been recognized as requiring very high integrity. In this basic study, ECT(eddy current testing) method for end-closure welding has been developed to detect end cap weld discontinuities for nuclear fuel safety. In order to improve the inspection reliability, the maximum scanning speed and the maximum frequency is investigated for end-closure welding inspection. The bandpass filter(0-250Hz) is used for removing noise effects. This study shows that ECT method is effective and sensitive for the detection of small defect(0.35mm diameter).

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Ultrasonic Inspection of Cracks in Stud Bolts of Reactor Vessels in Nuclear Power Plants by Signal Processing of Differential Operation

  • Choi, Sang-Woo;Lee, Joon-Hyun;Oh, Won-Deok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.6
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    • pp.439-445
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    • 2005
  • The stud bolt is one of crucial parts for safe operation of reactor vessels in nuclear power plants, Crack initiation and propagation were reported in stud bolts that arc used for closure of reactor vessel and head, Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure which could induce radioactive leakage from nuclear reactor, In conventional ultrasonic testing for inspection of stud bolts, cracks are detected by using shadow effect It takes too much time to inspect stud bolts by using conventional ultrasonic technique. In addition, there were numerous spurious signals reflected from every oblique surfaces of thread, In this study, the signal processing technique for enhancing conventional ultrasonic technique was introduced for inspecting stud bolts. The signal processing technique provides removing spurious signal reflected from every oblique surfaces of thread and enhances detectability of defects. Detectability for small crack was enhanced by using this signal processing in ultrasonic inspection of stud bolts in Nuclear Power Plants.

Stress Testing and Imaging Protocols for Myocardial Perfusion Studies (심근관류영상을 위한 심근부하 방법 및 검사 프로토콜)

  • Kim, Seong-Min
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.3
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    • pp.179-195
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    • 2009
  • Scince $^{201}$TI was introduced as a myocardial perfusion imaging agent in the early 1970s, scintigraphic evaluation of myocardial perfusion for the diagnosis of coronary artery disease is a valuable noninvasive diagnostic imaging modality. Stress radionuclide myocardial perfusion imaging is widely accepted to have high diagnostic and prognostic use in the assessment of patients with known or suspected coronary artery disease. With wise use of this nonivasive imaging technique, more patients are referred for stress perfusion imaging. Until now various protocols for stress testing and myocardial imaging were developed and used in worldwide. This article presented various protocols of stress testing and myocardial imaging for clinical use.

Preliminary Round Robin Test(RRT) for Program for the Inspection of Nickel Alloy Components(PINC) - Reactor Vessel Head Penetration (RVHP) -

  • Kim, Kyung-Cho;Kang, Sung-Sik;Shin, Ho-Sang;Song, Myung-Ho;Chung, Hae-Dong;Kim, Yong-Sik
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.3
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    • pp.256-263
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    • 2009
  • After several PWSCCs were found in Bugey(France), Ringhals(Sweden), Tihange(Belgium), Oconee, Arkansas, Crystal Fever, Davis-Basse, VC Summer(U.S.A.), Thuruga(Japan), USNRC and PNNL started the research on PWSCC, that is, the PINC project. USNRC required KINS to participate in the PINC project in May 2005. KINS organized the Korean consortium at March 2006 and Pre-RRT for RVHP were performed for the preparation of PINC RRT. Through these preliminary RRT, Korea NDE teams can learn and develop the detection and sizing technique for RVHP dissimilar metal weld. These techniques are now being prepared in Korea and need to be utilized for the In-service inspection of the RVHP and BMI of Korea Nuclear Power Plants. PINC RRT mock-ups will be helpful to training.

SUPERCRITICAL WATER LOOP DESIGN FOR CORROSION AND WATER CHEMISTRY TESTS UNDER IRRADIATION

  • Ruzickova, Mariana;Hajek, Petr;Smida, Stepan;Vsolak, Rudolf;Petr, Jan;Kysela, Jan
    • Nuclear Engineering and Technology
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    • v.40 no.2
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    • pp.127-132
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    • 2008
  • An experimental loop operating with water at supercritical conditions(25MPa, $600^{\circ}C$ in the test section) is designed for operation in the research reactor LVR-15 in UJV Rez, Czech Republic. The loop should serve as an experimental facility for corrosion tests of materials for in-core as well as out-of-core structures, for testing and optimization of suitable water chemistry for a future HPLWR and for studies of radiolysis of water at supercritical conditions, which remains the domain where very few experimental data are available. At present, final necessary calculations(thermalhydraulic, neutronic, strength) are being performed on the irradiation channel, which is the most challenging part of the loop. The concept of the primary and auxiliary circuits has been completed. The design of the loop shall be finished in the course of the year 2007 to start the construction, out-of-pile testing to verify proper functioning of all systems and as such to be ready for in-pile tests by the end of the HPLWR Phase 2 European project by the end of 2009.

Analysis of multiple spurious operation scenarios of Korean PHWRs using guidelines of nuclear power plants in U.S.

  • Kim, Jaehwan;Jin, Sukyeong;Kim, Seongchan;Bae, Yeonkyoung
    • Nuclear Engineering and Technology
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    • v.51 no.7
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    • pp.1765-1775
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    • 2019
  • Multiple spurious operations (MSOs) mean multiple fire induced circuit faults causing an undesired operation of one or more systems or components. The Nuclear Energy Institute (NEI) of the United States published NEI 00-01 as guidelines for solving MSOs. And this guideline includes MSO scenarios of pressurized water reactor (PWR) and boiling water reactor (BWR). Nuclear power plant operators in U.S. analyzed MSOs under MSO scenarios included in NEI 00-01 and operators of PWRs in Korea also analyzed MSOs under the scenarios of NEI 00-01. As there are no pressurized heavy water reactors (PHWRs) in the United States, MSO scenarios of PHWRs are not included in the NEI 00-01 and any feasible scenarios have not been developed. This paper developed MSO scenarios which can be applied to PHWRs by reviewing the 63 MSO scenarios included in NEI 00-01. This study found that seven scenarios out of the 63 MSO scenarios can be applied and three more scenarios need to be developed.

Development of long-term irradiation testing technology at HANARO

  • Choo, Kee Nam;Yang, Seong Woo;Park, Seng Jae;Shin, Yoon Taeg
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.344-350
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    • 2021
  • As the High Flux Advanced Neutron Application Reactor (HANARO) has been recently required to support new R&D relevant to future nuclear systems requiring a much higher neutron fluence, the development of irradiation capsule technology for long-term irradiation testing was performed in three steps (3, 5, 10 dpa). At first, several design improvements of a standard capsule were suggested based on a failure analysis of the capsule and successfully applied for irradiation testing at HANARO at up to eight reactor operation cycles equivalent to 3 dpa. Based on a schematic stress analysis of the vulnerable parts of the previous capsule, an optimized design of the capsule was made for 5 dpa irradiation. The newly designed capsule was safely out-pile tested up to 450 days, which was equivalent to 5 dpa irradiation in the reactor. The test results were submitted to the Reactor Safety Review Committee of HANARO and irradiation testing for 5 dpa was approved. The capsule was also successfully out-pile tested to evaluate the possibility of irradiation testing for 10 dpa. For a higher neutron fluence exceeding 10 dpa, new capsule technologies, including a new capsule that has a different bottom design and neutron flux boosting capsule, were also suggested.