• Title/Summary/Keyword: 중수로 압력관

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Development of Creep Deflection Analysis Method and Program for CANDU Pressure Tube (중수로 압력관의 크리프 처짐 해석 기법 및 프로그램 개발)

  • Shim, Do-Jun;Huh, Nam-Su;Park, Bo-Kyu;Chang, Yoon-Suk;Kim, Yun-Jae;Kim, Young-Jin;Jung, Hyun-Kyu
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.66-71
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    • 2004

  • Estimation of the CANDU pressure tube deflection is important since the deflection may cause significant structural failure due to hydrogen diffusion and blister. However, there is no appropriate engineering model to estimate it exactly. The purpose of this paper is to propose a new analysis method and program to resolve this issue. For development of proper analysis method, a series of finite element analyses has been carried under elastic-creep condition. In addition, for effective estimation of the creep deflection, an analysis program named PC-DAS was developed based on the proposed method. Comparison of simple case study results with corresponding reference ones showed good agreement. Therefore, the proposed method and program can be utilized as one of valuable toolkit for integrity assessment of CANDU pressure tube.

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Diameter Evaluation for PHWR Pressure Tube Based on the Measured Data (측정 데이터 기반 중수로 압력관 직경평가 방법론 개발)

  • Jong Yeob Jung;Sunil Nijhawan
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.19 no.1
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    • pp.27-35
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    • 2023

  • Pressure tubes are the main components of PHWR core and serve as the pressure boundary of the primary heat transport system. However, because pressure tubes have changed their geometrical dimensions under the severe operating conditions of high temperature, high pressure and neutron irradiation according to the increase of operation time, all dimensional changes should be predicted to ensure that dimensions remain within the allowable design ranges during the operation. Among the deformations, the diameter expansion due to creep leads to the increase of bypass flow which may not contribute to the fuel cooling, the decrease of critical channel power and finally the deration of the power to maintain the operational safety margin. This study is focused on the modeling of the expansion of the pressure tube diameter based on the operating conditions and measured diameter data. The pressure tube diameter expansion was modeled using the neutron flux and temperature distributions of each fuel channel and each fuel bundle as well as the measured diameter data. Although the basic concept of the current modeling approach is simple, the diameter prediction results using the developed methodology showed very good agreement with the real data, compared to the existing methodology.

  • https://doi.org/10.20466/KPVP.202.19.1.027 인용 PDF

Nondestructive Examination of PHWR Pressure Tube Using Eddy Current Technique (와전류검사 기술을 적용한 가압중수로 원전 압력관 비파괴검사)

  • Lee, Hee-Jong;Choi, Sung-Nam;Cho, Chan-Hee;Yoo, Hyun-Joo;Moon, Gyoon-Young
    • Journal of the Korean Society for Nondestructive Testing
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    • v.34 no.3
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    • pp.254-259
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    • 2014

  • A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter ${\times}$ 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the $D_2O$ heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

  • https://doi.org/10.7779/JKSNT.2014.34.3.254 인용 PDF KSCI

Hydrogen Embrittlement of Zr-2.5Nb PT with Temperature (Zr-2.5Nb 압력관의 온도변화에 따른 수소취화 파괴거동)

  • Oh, Dong-Joon;Ahn, Sang-Bok;Kim, Young-Suk
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.78-83
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    • 2003

  • The aim of this study is to investigate the effect of hydrogen embrittlement od Zr-2.5Nb CANDU pressure tube. The test were performed at three hydrogen contents for transverse tensile and CCT specimens while the test temperatures were changed (RT to 300$^{\circ}C$). The specimens were directly machined from the tube retaining original curvature using electric discharge machine. Both the transverse tensile and the fracture toughness tests showed the hydrogen embrittlement clearly at RT but this phenomenon was disappeared while the test temperature arrived over 250$^{\circ}C$. From the fracture toughness test, it was found that fracture toughness dJ/da was increased up to 200$^{\circ}C$ and then decreased.

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Zr-2.5wt.% Nb 합금의 인장강도 특성