Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Sensitivity Analysis of Finite Element Parameters for Estimating Residual Stress of J-Groove Weld in RPV CRDM Penetration Nozzle

원자로 CRDM 관통노즐 J-Groove 용접부 잔류응력 예측을 위한 유한요소 변수 민감도 해석

  • Bae, Hong-Yeol (Dept. of Mechanical Engineering, Korea Univ.) ;
  • Kim, Ju-Hee (Dept. of Mechanical Engineering, Korea Univ.) ;
  • Kim, Yun-Jae (Dept. of Mechanical Engineering, Korea Univ.) ;
  • Oh, Chang-Young (Dept. of Mechanical Engineering, Korea Univ.) ;
  • Kim, Ji-Soo (Dept. of Mechanical Engineering, Korea Univ.) ;
  • Lee, Sung-Ho (Central Research Institute, Korea Hydro and Nuclear Power Co. Ltd.) ;
  • Lee, Kyoung-Soo (Central Research Institute, Korea Hydro and Nuclear Power Co. Ltd.)
  • Received : 2011.11.07
  • Accepted : 2012.07.20
  • Published : 2012.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

In nuclear power plants, the reactor pressure vessel (RPV) upper head control rod drive mechanism (CRDM) penetration nozzles are fabricated using J-groove weld geometry. Recently, the incidences of cracking in Alloy 600 CRDM nozzles and their associated welds have increased significantly. The cracking mechanism has been attributed to primary water stress corrosion cracking (PWSCC), and it has been shown to be driven by welding residual stresses and operational stresses in the weld region. The weld-induced residual stress is the main factor contributing to crack growth. Therefore, an exact estimation of the residual stress is important for ensuring reliable operation. This study presents the residual stress computation performed for an RPV CRDM penetration nozzle in Korea. Based on two and three dimensional finite element analyses, the effect of welding variables on the residual stress variation is estimated for sensitivity analysis.

최근 원자로 압력용기 상부헤드 관통노즐 J-groove 용접부 주변에서 균열로 인한 냉각수 누출사고가 발행하고 있다. 이러한 사고의 원인은 용접에 의한 인장잔류응력, 농축된 붕산수 및 응력부식에 민감한 재료로 인한 일차수응력부식균열(PWSCC : primary water stress corrosion cracking)인 것으로 판명되었다. PWSCC 평가는 원자로 건전성 평가의 주요 관심사로서 용접에 의해 발생되는 잔류응력을 정확하게 예측함으로써 가능하다. 본 연구에서는 유한요소해석을 이용하여 국내 원자로의 일반적인 J-groove 용접부의 해석절차를 소개하고, 용접해석 관련 변수의 민감도 해석을 통해 잔류응력 예측기법을 제시하고자 한다. 이를 위해 2 차원 및 3 차원 요한요소해석 방법을 바탕으로 변수 민감도 해석을 수행하였으며, 기존 연구결과와 비교를 통해 해석절차 및 방법의 유용성을 검정하였다.

Keywords

References

  1. Anderson, MT., Rudland, D., Zhang, T. and Wilkowski, GM., 2008, "Final Report-Inspection Limit Confirmation for Upper Head Penetration Nozzle Cracking," U.S. Department of Energy, pp. 1-22.
  2. Rudland, D., Chen, Y., Zhang, T., Wilkowski, G., Broussard, J. and White, G., 2007, "Comparison of Welding Residual Stress Solutions for Control Rod Drive Mechanism Nozzles," Trans. of ASME PVP conference, PVP2007-26045, pp. 1-15.
  3. Cheng, W., Rudland, D., Wilkowski, G. and Norris, W., 2005, "Effects Of Weld Geometry On Residual Stress and Crack Driving Force For Centerhole Control Rod Drive Mechanism Nozzles - Part I Weld Residual Stress," Trans. of ASME PVP conference, PVP2005-71077, pp. 1-6.
  4. ASME B&PV Committee, 2007, ASME B&PV Code Case Section XI Division 1, Nonmandatory Appendix O-3000.
  5. COMBUSTION ENGINEERING, INC., 1981, Analytical Report for Korea Nuclear Unit No. 5 Reactor Vessel, CENC-1466, pp. 1403-1488.
  6. Kim, J. H., Kim, Y. J., Lee, S. H., Hur, N. Y., Bae, H. Y., Oh, C. Y., Kim, J. S., Lee, S. H., Park, H. B., Lee, S. G., Kim, J. S. and Huh, N. S., 2011, "Effects of Geometry of Reactor Pressure Vessel Upper Head Control Rod Drive Mechanism Penetration Nozzles on J-Groove Weld Residual Stress," Trans. of the KSME (A), Vol. 35, pp. 1337-1345. https://doi.org/10.3795/KSME-A.2011.35.10.1337
  7. ASME B&PV Committee, 1998, ASME B&PV Code Case Section III Division 1 NB-4000, p. 193.
  8. Kim, J. S., Jin, T. Dong, E. and Prager, P., 2003, "Development of Residual Stress Analysis Procedure for Fitness-For-Service Assessment of Welded Structure," Trans. of the KSME (A), Vol. 27, pp. 713-723. https://doi.org/10.3795/KSME-A.2003.27.5.713
  9. ABAQUS, 2003, ABAQUS Standard/User's Manual, version 6.9, Hibbit Karlsson & Sorensen, Inc.
  10. Song, T. K., Bae, H. Y., Kim, Y. J., Lee, K. S. and Park, C. Y., 2008, "Sensitivity Analyses of Finite Element Method for Estimating Residual Stress of Dissimilar Metal Multi-Pass Weldment in Nuclear Power Plant," Trans. of the KSME (A), Vol. 32, pp. 770-781. https://doi.org/10.3795/KSME-A.2008.32.9.770
  11. ASME B&PV Committee, 2008, ASME B&PV Code Sec. II, PART A, B, C.
  12. Special metals, 2008, Inconel alloy 600, Special Metals Corporation Publication, No. SMC-207, September.
  13. ASME B&PV Committee, 2007, ASME B&PV Code Sec. III, Appendices.
  14. Lee, S. G., Kim, J. S. and Jin, T. E., 2004, "A Study for Mitigating Residual Stress in CRDM Penetration Nozzle Weld," Trans. of the KSME Spring conference, pp. 90-95.
  15. Song, T. K., Chun, Y. B., Oh, C. Y., Bae, H. Y., Kim, Y. J., Lee, S. H., Lee, K. S. and Park, C. Y., 2009 "Effects of Similar Metal Weld on Residual Stress in Dissimilar Metal Weld According to Safe End Length," Trans. of the KSME (A), Vol. 33, pp. 664-672. https://doi.org/10.3795/KSME-A.2009.33.7.664
  16. Ogawa, K., Deng, D., Kiyoshima, S., Yanagida, N. and Saito, K., 2009, "Influences of Heat Source Model on Welding Residual Stress and Distortion in a Multi- Pass J-Groove Joint," J. of Computation Materials Science, Vol. 46, pp. 987-995. https://doi.org/10.1016/j.commatsci.2009.05.002
  17. Yaghi, A., Gyde, H., Becker, A., Sun, W. and Williams, J. A., 2006, "Residual Stress Simulation in Thin and Thick-walled Stainless Steel Pipe Welds Including Pipe Diameter Effects," Int. J. of Pressure Vessels and Piping, Vol. 83, pp. 864-874. https://doi.org/10.1016/j.ijpvp.2006.08.014
  18. Brickstad, B., Josefson, B., 1998, "A Parametric Study of Residual Stresses in Multi-Pass Butt-Welded Stainless Steel Pipes," Int. J. of Pressure Vessels and Piping, Vol. 75, pp. 11-25. https://doi.org/10.1016/S0308-0161(97)00117-8
  19. Kiyoshima, S., Deng, D., Ogawa, K., Yanagida, N. and Saito, K., 2009, "Investigations on Welding Residual Stresses in Penetration Nozzles by Means of 3D thermal elastic plastic FEM and experiment," J. of Computation Materials Science, Vol. 45, pp. 1031-1042. https://doi.org/10.1016/j.commatsci.2009.01.008
  20. Alternate Examination Requirements for PWR Reactor Vessel Upper Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds. 2006, ASME Code Case N-729-1
  21. ASME, 2004, "Welding and Brazing Qualification," ASME Boiler and Pressure Vessel Code, Sec. IX
  22. British Energy Generation Ltd., 2001, "Assessment of the Integrity of Structures Containing Defects," R6 Revision 4.
  23. Leggatt, N. A., Dennis, R. and Hurrel, P. R., 2007, "Modeling the Fabrication of a Pressure Vessel Toroidal Seal," Trans. of ASME PVP conference, PVP2007-26145.
  24. Dennis, R. J., Leggatt, N. A. and Gregg, A., 2006, "Optimisation of Weld Modeling Techniques : Bead on Plate Analysis," Trans. of ASME PVP Conference, PVP2006-ICPVT-11-93907.
  25. Bate, S. K., Warren, A. P., Watson, C. T., Hurrel, P. and Francis, J. A., 2007, "UK Research Programme on Residual Stresses - Progress to Date," Trans. of ASME PVP conference, PVP2007-26337.
  26. Dong, P. and Brust, F. W., 2000, "Welding Residual Stresses and Effects on Fracture in Pressure Vessel and Piping Components : A Millennium Review and Beyond," J. of Pressure Vessel Technology, Vol. 122, pp. 329-338. https://doi.org/10.1115/1.556189
  27. Warren, A. P., Bate, S. K. and 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 Cconference, PVP2007-26339.

Cited by

  1. Effect of Normal Operating Condition Analysis Method for Weld Residual Stress of CRDM Nozzle in Reactor Pressure Vessel vol.37, pp.9, 2013, https://doi.org/10.3795/KSME-A.2013.37.9.1159
  2. Residual Stress Analysis of Repair Welded Rail Using the ABAQUS User Subroutine vol.33, pp.7, 2016, https://doi.org/10.7736/KSPE.2016.33.7.551
  3. PWSCC initiation and propagation in a CRDM penetration nozzle vol.31, pp.11, 2017, https://doi.org/10.1007/s12206-017-1033-0