0
Research Papers: Design and Analysis

Numerical Validations of Flaw Shape Idealization Methods to Burst Pressure Estimations of Steam Generator Tube With Axial Surface Flaws

[+] Author and Article Information
Seung-Hyun Park, Jae-Boong Choi

School of Mechanical Engineering,
Sungkyunkwan University,
2066 Seobu-ro, Jangan-gu,
Suwon 16419, Gyeonggi-do, South Korea

Nam-Su Huh

Department of Mechanical System Design
Engineering,
Seoul National University of Science
and Technology,
232 Gongneung-ro, Nowon-gu,
Seoul 01811, South Korea
e-mail: nam-su.huh@seoultech.ac.kr

Sang-Min Lee, Yong-Beum Kim

Korea Institute of Nuclear Safety,
62 Gwahak-ro, Yuseong-gu,
Daejeon 34142, South Korea

1Corresponding author.

Contributed by the Pressure Vessel and Piping Division of ASME for publication in the JOURNAL OF PRESSURE VESSEL TECHNOLOGY. Manuscript received July 10, 2017; final manuscript received October 21, 2017; published online December 1, 2017. Assoc. Editor: David L. Rudland.

J. Pressure Vessel Technol 140(1), 011202 (Dec 01, 2017) (8 pages) Paper No: PVT-17-1123; doi: 10.1115/1.4038310 History: Received July 10, 2017; Revised October 21, 2017

This work investigates the applicability of the flaw shape idealization methods to carry out the structural integrity assessment of steam generator (SG) tubes under internal pressure with complicated axial inner and outer surface flaws that were typically found during the in-service-inspection (ISI). In terms of flaw shape, three different shapes of flaws which can be detected during an actual ISI are considered, i.e., long symmetric flaw, asymmetric inclined flaw and narrow, symmetric deep flaw. As for flaw shape idealization methods for the predictions of burst pressures of these flaws, four different flaw shape idealization models, i.e., semi-elliptical, rectangular, maximum length with effective flaw depth and weakest subcrack model proposed by the Electric Power Research Institute (EPRI) are employed in this work. In order to validate the applicability of these idealization methods, the burst pressures of SG tubes with these flaws are investigated by using the finite element (FE) analyses. By comparing the predictions of the burst pressures based on the four different flaw shape idealization methods with those based on actual flaw shapes, it is found that the weakest subcrack model proposed by the EPRI and maximum length with effective flaw depth model provide the better agreement with actual complex flaw.

FIGURES IN THIS ARTICLE
<>
Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

MacDonald, P. E. , Shah, V. N. , Ward, L. W. , and Ellison, P. G. , 1996, “ Steam Generator Tube Failure,” U.S. Nuclear Regulatory Commission, Rockville, MD, Report No. NUREG/CR-6365.
Kang, S. C. , and Song, M. H. , 1999, “ Regulatory Technical Report on the Steam Generator Safety of Nuclear Power Plants,” Korea Institute of Nuclear Safety, Daejeon, Korea, Report No. KINS/AR-669.
Lee, J. H. , 1993, “ A Comparing Study of Alloy 600 and Alloy 690 on Resistance to Intergranular Stress Corrosion Cracking (IGSCC),” Master's thesis, Department of Nuclear Engineering, Korea University, Seoul, Korea.
Fujimori, H. , Sanchez, I. G. , Gott, K. , Hwang, S. S. , Richard, J. J. , Kang, K. S. , Kupca, L. , Molander, A. , Scott, P. , Takamori, K. , Tanaka, H. , Widera, M. , Winter, M. , Yaguchi, S. , Yamamoto, A. , and Yamashita, N. , 2011, “ Stress Corrosion Cracking in Light Water Reactors: Good Practices and Lessons Learned,” International Atomic Energy Agency, Vienna, Austria, Report No. NP-T-3.13.
Bandy, R. , and van Rooyen, D. , 1984, “ Initiation and Propagation of Stress-Corrosion Cracking of Alloy 600 in High-Temperature Water,” U.S. Nuclear Regulatory Commission, Rockville, MD, Technical Report No. BNL-NUREG-33657.
Kim, H. S. , Kim, J. S. , Jin, T. E. , Kim, H. D. , and Chung, H. S. , 2006, “ Evaluation of Limit Loads for Surface Cracks in the Steam Generator Tube,” Trans. Korean Soc. Mech. Eng. A, 30(8), pp. 993–1000. [CrossRef]
Kim, Y. J. , Shim, D. J. , Huh, N. S. , and Kim, Y. J. , 2002, “ Plastic Limit Pressure for Cracked Pipes Using Finite Element Limit Analyses,” Int. J. Pressure Vessels Pipes, 79(5), pp. 321–330. [CrossRef]
Tonković, Z. , Skozrit, I. , and Alfirević, I. , 2008, “ Influence of Flow Stress Choice on the Plastic Collapse Estimation of Axially Cracked Steam Generator Tubes,” Nucl. Eng. Des., 238(7), pp. 1762–1770. [CrossRef]
Merilo, M. , 2001, “ Effect of Pressurization Rate on Degraded Steam Generator Tubing Burst Pressure,” Electric Power Research Institute, Palo Alto, CA, EPRI Report No. 1001441.
ASME, 2007, “ ASME Boiler and Pressure Vessel Code, Section XI, Division 1, IWA-3300, Rules for In-Service Inspection of Nuclear Power Plant Components,” American Society of Mechanical Engineers, New York.
Merilo, M. , 2001, “ Steam Generator Degradation Specific Management Flaw Handbook,” Electric Power Research Institute, Palo Alto, CA, EPRI Report No. 1001191.
Cochet, B. , and Flesch, B. , 1987, “ Crack Stability Criteria in Steam Generator Tubes ,” Ninth International Conference on Structural Mechanics in Reactor Technology (SMIRT), Lausanne, Switzerland, Aug. 18–21, pp. 413–419.
Flesch, B. , and Cochet, B. , 1990, “ Leak Before Break in Steam Generator Tubes,” Int. J. Pressure Vessels Pipes, 43(1–3), pp. 165–179. [CrossRef]
Cothron, H. , 2007, “ Steam Generator In Situ Pressure Test Guideline, Revision 3,” Electric Power Research Institute, Palo Alto, CA, EPRI Report No. 1014983.
ASME 2007, “ ASME Boiler and Pressure Vessel Code, Section XI, Division 1, IBW-3521.1, Rules for In-Service Inspection of Nuclear Power Plant Components,” American Society of Mechanical Engineers, New York.
USNRC, 1976, “ Base for Plugging Degraded PWR Steam Generator Tubes,” Regulatory Guide, U.S. Nuclear Regulatory Commission, Rockville, MD, Report No. REG/G-1.121.
SIMULIA, 2011, “ ABAQUS Version 6.11, Analysis User's Manual,” Dassault Systèmes Corporation, Paris, France.
Wilkowski, G. M. , Krishnaswamy, P. , Uddin, M. , Punch, E. , and Hioe, Y. , 2016, “ Development Towards a Novel Approach for Assessment of Corroded Pipe,” ASME Paper No. IPC2016-64315.

Figures

Grahic Jump Location
Fig. 4

Schematics of flaw shape idealization methods: (a) maximum length with effective depth flaw model [11], (b) semi-elliptical flaw model [10], and (c) rectangular flaw model [7]

Grahic Jump Location
Fig. 2

Schematics of three types of axial surface flaws employed in this work

Grahic Jump Location
Fig. 1

Schematics of SG tube with axial surface flaw at inner and outer surfaces

Grahic Jump Location
Fig. 3

Flaw shape idealization using EPRI's weakest sub-crack model [11]: (a) discrete segments along the flaw length and (b) selected weakest subcrack model

Grahic Jump Location
Fig. 5

Comparison of actual flaw shape with idealized results based on four flaw shape idealization methods (case 1 of type1)

Grahic Jump Location
Fig. 6

Typical FE model of SG tube with axial inner and outer surface flaw

Grahic Jump Location
Fig. 7

Enlarged FE model of flaw surface for long, symmetric axial inner surface flaw: (a) FE mesh of flaw surface for actual flaw, (b) FE mesh of flaw surface for semi-elliptical flaw model, (c) FE mesh of flaw surface for rectangular flaw model, (d) FE mesh of flaw surface for Lmax and deff flaw model, and (e) FE mesh of flaw surface for weakest subcrack model

Grahic Jump Location
Fig. 8

Comparison of the present FE burst pressures with the existing plastic limit pressure solutions [7]

Grahic Jump Location
Fig. 9

Normalized FE burst pressures of actual and idealized flaws for axial inner surface flaw: (a) inner surface flaw, type 1, (b) inner surface flaw, type 2, and (c) inner surface flaw, type 3

Grahic Jump Location
Fig. 10

Normalized FE burst pressures of actual and idealized flaws for axial outer surface flaw: (a) outer surface flaw, type 1, (b) outer surface flaw, type 2, and (c) outer surface flaw, type 3

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In