Estimation of Residual Stress Distribution for Pressurizer Nozzle of Kori Nuclear Power Plant Considering Safe End

고리 원전 가압기 노즐 용접부 잔류응력 예측 시 안전단 고려가 이종 금속 용접부 잔류응력 분포에 미치는 영향

  • 송태광 (고려대학교 대학원 기계공학과) ;
  • 배홍열 (고려대학교 대학원 기계공학과) ;
  • 전윤배 (고려대학교 대학원 기계공학과) ;
  • 오창영 (고려대학교 대학원 기계공학과) ;
  • 김윤재 (고려대학교 기계공학과) ;
  • 이경수 (한전 전력연구원) ;
  • 박치용 (한전 전력연구원)
  • Published : 2008.08.01


In nuclear power plants, ferritic low alloy steel nozzle was connected with austenitic stainless steel piping system through alloy 82/182 butt weld. Accurate estimation of residual stress for weldment is important in the sense that alloy 82/182 is susceptible to stress corrosion cracking. There are many results which predict residual stress distribution for alloy 82/182 weld between nozzle and pipe. However, nozzle and piping system usually connected through safe end which has short length. In this paper, residual stress distribution for pressurizer nozzle of Kori nuclear power plant was predicted using FE analysis, which consideded safe end. As a result, existing residual stress profile was redistributed and residual stress of inner surface was decreased specially. It means that safe end should be considered to reduce conservatism when estimating the piping system.


Residual Stress;Dissimilar Metal Weld;PWSCC;Safe End


  1. EPRI, 2004, “Materials Reliability Program : Welding Residual and Operating Stresses in PWR Alloy 182 Butt Welds (MRP-106), EPRI Report
  2. Moffat, G., Bamford, W. H., Seeger, D., 2001, “Development of the Technical Basis for Plant Startup for the V.C Summer Nuclear Plant,” Trans. of ASME PVP conference, PVP-Vol. 427, pp. 33-39
  3. Fox, M., 1979, “An Overview of Intergranular Corrosion Cracking in BWRs,” Journal of materials in energy system, 1:3
  4. Yaghi, A., Gyde, T. H., Becker, A. A., Sun, W., Williams, J. A., 2006, “Residual Stress Simulation in Thin and Thick-Walled Stainless Steel Pipe Welds Including Pipe Diameter Effects,” International Journal of Pressure Vessels and Piping, Vol. 83, pp. 864-874
  5. Courtin, S., Gilles, P., 2006, “Detailed Simulation of an Overlay Repair on a 14” Dissimilar Material Weld,” Trans. of ASME PVP Conference, PVP2006-ICPVT-11-93823
  6. British Energy Generation Ltd., 2006, “Assessment of the Integrity of Structures Containing Defects,” R6, Revision 4
  7. Limpus, C.R., Dijamco, D. G., Bax R, Cofie, Nathaniel G., , 2007, “Effect of Size of Butt Weld Repaires on Weld Overlay Residual Stresses,” Trans. of ASME PVP conference, PVP2007-26636
  8. Brust, F. W., Scott, P. M., 2007, “Weld Residual Stresses and Primary Water Stress Corrosion Cracking in Bimetal Nuclear Pipe Welds,” Trans. of ASME PVP Conference, PVP2007-26297
  9. Special Metals Corporation, 2007, “Inconel 600 Information,”
  10. Brickstad, B., Josefson, B. L., 1998, “A Parametric Study of Residual Stresses in Multi-Pass Butt-Welded Stainless Steel Pipes,” International Journal of Pressure Vessels and piping, Vol. 75, pp.11-25
  11. Elocate, C.D., Dennis, R.J., Bouchard, P.J., Smith, M.C., 2005, “Three Dimensional Multi-Pass Repair Weld Simulations,” International Journal of Pressure Vessels and Piping, Vol. 82, pp. 244-257
  12. ASME, 2004, “Materials,” ASME Boiler and Pressure Vessel Code, Sec. II, Part D-properties”
  13. ABAQUS, 2003, “ABAQUS Standard/User's Manual, Version 6.4,” Hibbit Karlsson & Sorensen, Inc
  14. ASME, 2004, “Welding and Brazing Qualification ,” ASME Boiler and Pressure Vessel Code, Sec. IX
  15. KEPRI,2008,”A FEM Analysis Guideline for Residual Stress in Dissimilar Metal Welds,” KEPRI report
  16. Dawling, N. E., 1999, “Mechanical Behavior of Materials,” Prentice Hall, $2^{nd}$ edition
  17. Leggatt, N. A., Dennis, R., Hurrel, P. R., 2007, “Modeling the Fabrication of a Pressure Vessel Toroidal Seal,” Trans. of ASME PVP Conference, PVP2007-26145
  18. Dennis, R. J., Leggatt, N. A., Gregg, A., 2006, “Optimisation of Weld Modeling Techniques – Bead on Plate Analysis, Trans. of ASME PVP Conference, PVP2006-ICPVT-11-93907
  19. Dong, P., Brust, F. W., 2000, “Welding Residual Stresses and Effects on Fracture in Pressure Vessel and Piping Components : A Millennium Review and Beyond,” Journal of Pressure Vessel Technology, Vol. 122, pp. 329-338
  20. Bate, S. K., Warren, A. P., Watson, C. T., Hurrel, P., Francis, J. A., 2007, “UK Research Programme on Residual Stresses–Progress to Date,” Trans. of ASME PVP Conference, PVP2007-26337
  21. Brust, F. W., Scott, P., 2007, “Primary Water Stress Corrosion Cracking (PWSCC) in Bimetal Nuclear,” Trans. of SMiRT 19 conference, PVP-Vol. 427, pp, 33-39SMiRT 19
  22. Warren, A. P., Bate, S. K., Hurrell, P., 2007, “The Effect of Modeling Simplification on the Prediction of Residual Stresses in a Multi-Pass Plate Groove Weld,” Trans. of ASME PVP conference, PVP2007-26339
  23. Hurrell, P. R., Everett, D., Gregg, A., Bate, S., 2006, “Review of Residual Stress Mitigation Methods for Application in Nuclear Power Plant,” Trans. of ASME PVP conference, PVP2006-ICPVT-11-93381
  24. Kim, J.S, Jin, T.E., Dong, P., Prager, M., 2003, “Development of Residual Stress Analysis Procedure for Fitness-For-Service Assessment of Welded Structure,” Transactions of the KSME(A), Vol. 27, pp.713-723
  25. U.S. Nuclear Regulatory Commission, 1992, “Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary Piping-Final Report,” NUREG-0313, Revision 2
  26. Dong, P., 2001, “Residual Stress Analyses of a Multi-Pass Girth Weld: 3-D Special Shell Versus Axisymmetric Models,” ASME Journal of Pressure Vessel Technology, Vol. 123, pp. 207-213
  27. Song,T.K., Bae,H.Y., Kim, Y.J., Lee, K.S., Park, C.Y., 2008, “Sensitivity Analyses of Finite Element Method for Estimating Residual Stress of Dissimilar Metal Multi-Pass Welding,” Submitted to Transactions of the KSME(A)

Cited by

  1. A Study on Machining Effects on Residual Stress at Dissimilar Metal Weld Region vol.29, pp.2, 2011,
  2. Stress Distribution in the Dissimilar Metal Butt Weld of Nuclear Reactor Piping due to the Simulation Technique for the Repair Welding vol.37, pp.5, 2013,
  3. Stress Modeling of the Laser Drilling Process in Carbon Steel vol.37, pp.7, 2013,
  4. Investigation into Variations of Welding Residual Stresses and Redistribution Behaviors for Different Repair Welding Widths vol.38, pp.2, 2014,
  5. Effects of Similar Metal Weld on Residual Stress in Dissimilar Metal Weld According to Safe End Length vol.33, pp.7, 2009,
  6. Welding Residual Stress Determination and Crack Analysis in Butt-Welded Thin-Walled Plate by Finite-Element Method vol.34, pp.5, 2010,
  7. Effects on Machining on Surface Residual Stress of SA 508 and Austenitic Stainless Steel vol.35, pp.5, 2011,
  8. Study on Effect of Mechanical Machining and Heat Treatment on Surface Residual Stress of TP316L Stainless Steel vol.35, pp.5, 2011,
  9. Evaluation for Weld Residual Stress and Operating Stress around Weld Region of the CRDM Nozzle in Reactor Vessel Upper Head vol.36, pp.10, 2012,
  10. Crack Growth Analysis due to PWSCC in Dissimilar Metal Butt Weld for Reactor Piping Considering Hydrostatic and Normal Operating Conditions vol.37, pp.1, 2013,
  11. Finite element analysis and measurement for residual stress of dissimilar metal weld in pressurizer safety nozzle mockup vol.23, pp.11, 2009,