DOI QR코드

DOI QR Code

원자력발전소 고강도 앵커 볼트의 파괴역학적 건전성평가

Structural Integrity Assessment of High-Strength Anchor Bolt in Nuclear Power Plant based on Fracture Mechanics Concept

  • 임은모 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 허남수 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 심희진 (KEPCO E&C 전력기술연구소) ;
  • 오창균 (KEPCO E&C 전력기술연구소) ;
  • 김현수 (KEPCO E&C 전력기술연구소)
  • Lim, Eun-Mo (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Huh, Nam-Su (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Shim, Hee-Jin (Power Engineering Research Institute, KEPCO Engineering & Construction Company, Inc.) ;
  • Oh, Chang-Kyun (Power Engineering Research Institute, KEPCO Engineering & Construction Company, Inc.) ;
  • Kim, Hyun-Su (Power Engineering Research Institute, KEPCO Engineering & Construction Company, Inc.)
  • 투고 : 2012.12.28
  • 심사 : 2013.04.15
  • 발행 : 2013.07.01

초록

증기발생기 수직 지지대를 고정하고 있는 고강도 앵커 볼트의 응력부식균열에 대한 건전성 평가는 원자력발전소 기기 건전성 유지와 관련하여 중요한 현안 가운데 하나이다. 이에 따라 미국 EPRI에서는 고강도 앵커 볼트의 건전성 평가를 위한 기준균열계수 개념 기반의 평가 절차를 제시한 바 있으며, 본 연구에서는 EPRI에서 제시한 절차에 입각하여 증기발생기 수직 지지대 고정용 앵커 볼트의 응력부식균열 및 취성 파괴에 대한 건전성 평가를 수행하였다. 이를 위해 볼트 예비하중과 운전하중을 고려한 3차원 유한요소 응력해석을 수행하여 볼트 단면에 작용하는 공칭응력을 결정하였으며, 결정된 볼트 응력과 EPRI 절차를 이용하여 앵커 볼트의 균열 건전성을 평가하였다. 또한 3차원 탄성 유한요소 파괴역학 해석을 수행하여 EPRI에서 제시한 기준균열계수의 정확성을 검증하였다.

The failure of a bolted joint owing to stress corrosion cracking (SCC) has been considered one of the most important structural integrity issues in a nuclear power plant. In this study, the failure possibility of bolting, which is used to support the steam generator of a pressurized water reactor, owing to SCC and brittle fracture was evaluated in accordance with guidelines proposed by the Electric Power Research Institute, which are called the Reference Flaw Factor method. For this evaluation, first, detailed finite element stress analyses were conducted to obtain the actual nominal stresses of bolting in which either service loads or bolt preloads were considered. Based on these nominal stresses, the structural integrity of bolting was addressed from the viewpoints of SCC and toughness. In addition, the accuracy of the EPRI Reference Flaw Factor for assessing bolting failure was investigated using finite element fracture mechanics analyses.

키워드

참고문헌

  1. USNRC, 1982, "Bolting Degradation or Failure in Nuclear Power Plants," GSI-29.
  2. EPRI, 1995, "Bolted Joint Maintenance and Applications Guide," TR-104213.
  3. USNRC, 1990, "Resolution of Genetic Safety Issue 29-Bolting Degradation or Failure in Nuclear Power Plants," NUREG-1339.
  4. EPRI, 1988, "Degradation and Failure of Bolting in Nuclear Power Plants," EPRI NP-5769.
  5. "ANSYS Workbench User's Manual," ANSYS Version 13.0, Mechanical APDL.
  6. EPRI, 1984, "Requirements and Guidelines for Evaluating Component Support Material under Unresolved Safety Issue A-12," EPRI NP-3528.
  7. "ABAQUS/Standard User's Manual," ABAQUS Version 6.10-1, Dassault Systemes Corp.

피인용 문헌

  1. Prediction of Joining Torque for Bit Depth of Subminiature Bolt vol.38, pp.8, 2014, https://doi.org/10.3795/KSME-A.2014.38.8.917