• 제목/요약/키워드: Zr-2.5Nb Pressure Tube

검색결과 46건 처리시간 0.029초

A way Analyzing Oxide Layer on an Irradiated CANDU-PHWR Pressure Tube Using an EPMA and X-ray Image Mapping

  • Jung, Yang Hong;Kim, Hee Moon
    • Corrosion Science and Technology
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    • 제20권3호
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    • pp.118-128
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    • 2021

  • The oxide layer in samples taken from an irradiated Zr-2.5Nb pressure tube from a CANDU-PHWR reactor was analyzed using electron probe microanalysis (EPMA). The examined tube had been exposed to temperatures ranging from 264 to 306 ℃ and a neutron fluence of 8.9 × 1021 n/cm2 (E > 1 MeV) for the maximum 10 effective full-power years in a nuclear power plant. Measuring oxide layer thickness generally employs optical microscopy. However, in this study, analysis of the oxide layer from the irradiated pressure tube components was undertaken through X-ray image mapping obtained using EPMA. The oxide layer characteristics were analyzed by X-ray image mapping with 256 × 256 pixels using EPMA. In addition, the slope of the oxide layer was measured for each location. A particular advantage of this study was that backscattered electrons and X-ray image mapping were obtained at a magnification of 9,000 when 20 kV volts and 30 uA of current were applied to radiation-shielded EPMA. The results of this study should usefully contribute to the study of the oxide layer properties of various types of metallic materials irradiated by high radiation in nuclear power plants.

  • https://doi.org/10.14773/cst.2021.20.3.118 인용 PDF KSCI

CANDU형 핵연료 채널 압력관에 대한 원거리장 와전류의 자제분포 특성해석(I) (A FEM Analysis of Remote Field Eddy Current Distribution Characteristics to CANDU Fuel Channel Tube(I))

  • 허형;정현규;김건중
    • 비파괴검사학회지
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    • 제22권1호
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    • pp.59-64
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    • 2002

  • CANDU형 핵연료채널 압력관(Zr-2.5%Nb)과 calandria관(Zircaloy-2)에 대한 원격장 와전류탐상의 자계분포특성을 파악하기 위하여 유한요소 해석을 수행하였다. 압력관과 칼란드리아관의 전자기장 분포와 위상각 해석을 통하여 최적 검사 주파수와 감지코일의 위치를 평가하였다. 또한 축대칭 구조물(Al-ring과 Al-block)이 공존시 파라미터해석을 통하여 원격장 와전류의 특성을 평가하였다.

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Zr-2.5Nb 중수로 압력관의 조사후 강도 및 파괴거동 특성 (The Strength and Fracture Behavior characteristics of Irradiated Zr-2.5Nb CANDU Pressure Tube Materials)

  • 안상복;김영석;김정규
    • 대한기계학회논문집A
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    • 제25권3호
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    • pp.510-519
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    • 2001

  • The tensile and fracture toughness tests have been conducted to investigate the degradations of mechanical properties induced mainly by neutron irradiations in Zr-2.5Nb CANDU pressure tube materials operated in Wolsung Unit-1. the tests were performed at room, 150, 200, 250, 300 $\^{C}$ for the irradiated and unirradiated specimens in hot cell. The specimens were directly machined from the tube retaining original curvature using specially designed electric discharge machine(EDM). From the tensile tests of the irradiated specimens, it was found that tensile strength was increased and total elongation was decreased compared to those of the unirradiated ones. The active voltages in the fracture toughness tests for the irradiated showed the discontinuous abrupt increases caused by crack jumping in lower temperature. In the crack resistance curves we found the stable crack growth in the unirradiated, whereas the unstable and three crack growth stages in the irradiated specimens due to the accumulated irradiation defects. The various fracture characteristic values in the irradiated are remarkably lower than those of the unirradiated. Through the fractography, we found in the irradiated that smaller dimple and shorter fissures than the unirradiated, and that the fractured surface had three regions that were flat, transition and slant/shear area. These can explain the difference in the crack growth characteristic values of the irradiated and the unirradiated ones.

  • https://doi.org/10.22634/KSME-A.2001.25.3.510 인용 PDF

확률론적 파괴역학 기법을 이용한 압력관의 파손확률 평가 (Failure Probability Evaluation of Pressure Tube using the Probabilistic Fracture Mechanics)

  • 손종동;오동준
    • 한국안전학회지
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    • 제22권4호
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    • pp.7-12
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    • 2007

  • In order to evaluate the integrity of Zr-2.5Nb pressure tubes, probabilistic fracture mechanics(PFM) approach was employed. Failure assessment diagram(FAD), plastic collapses, and critical crack lengths(CCL) were used for evaluating the failure probability as failure criteria. The Kr-FAD as failure assessment diagram was used because fracture of pressure tubes occurred in brittle manner due to hydrogen embrittlement of material by deuterium fluence. The probabilistic integrity evaluation observed AECL procedures and used fracture toughness parameters of EPRI and recently announced theory. In conclusion, the probabilistic approach using the Kr-FAD made it possible to determine major failure criterion in the pressure tube integrity evaluation.

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