Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Modification of the ASME Code Z-Factor for Circumferential Surface Crack in Nuclear Ferritic Pipings

원전 페라이트 배관내의 원주방향 표면균열에 대한 ASME Code Z-Factor의 수정

  • Park, Y. H. (Korea Institute of Nuclear Safety) ;
  • Y. K. Chung (Korea Institute of Nuclear Safety) ;
  • W. Y. Koh (Korea Institute of Nuclear Safety) ;
  • Lee, J. B. (Korea Institute of Nuclear Safety)
  • Published : 1996.04.01
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Abstract

The purpose of this paper is to modify the ASME Code Z-Factor, which is used in the evaluation of circumferential surface crack in nuclear ferritic pipings. The ASME Code Z-Factor is a load multiplier to compensate plastic load with elasto-plastic load. The current ASME Code Z-Factor underestimates pipe maximum load. In this study, the original SC. TNP method is modified first because the original SC. TNP method has a problem that the maximum allowable load predicted from the original SC. TNP method is slightly higher than that measured from the experiment. Then the new Z-Factor is developed using the modified SC. TNP method. The desirability of both the modified SC. TNP method and the new Z-Factor is examined using the experimental results for the circumferential surface crack in pipings. The results show that (1) the modified SC. TNP method is good for predicting the circumferential surface crack behavior in pipings, and (2) the Z-Factor obtained from the modified SC. TNP method well predicts the behavior of circumferential surface crack in ferritic pipings.

이 연구의 목적은 원자력발전소 페라이트 배관에 존재하는 원주방향 표면균열을 평가하는데 사용되는 ASME Code Z-Factor를 수정하는데 있다. ASME Code Z-Factor는 소성하중을 탄소성하중으로 보정하는 하중 보정 계수로서, 현재 사용되는 ASME Code Z-Factor는 최대하중을 과소평가하는 문제점이 있다. 이 연구에서는 먼저 기존의 SC. TNP방법이 수정되었으며, 그 이유는 기존의 SC. TNP 방법으로 예측된 최대허용하중이 실험에서 측정된 방법보다 약간 큰 결과를 주는 문제가 있기 때문이다. 이 수정된 SC. TNP 방법을 사용하여 페라이트 배관에 대한 새로운 Z-Factor를 개발하였다. 수정된 SC. TNP 방법의 타당성 과 새로 개발된 Z-Factor의 타당성을 원주방향 표면균열을 갖는 배관에 대한 실험 결과를 통해 조사하였다. 평 가결과는 수정된 SC. TNP 방법은 페라이트 및 오스테나이트 배관의 원주 방향 표면균열의 거동을 잘 예측할 수 있음을 보여 주며, 또한 수정된 SC. TNP 방법으로 구한 새로운 Z-Factor는 페라이트 배관에 존재하는 원주방향 표면균열의 거동을 잘 예측할 수 있음을 보여준다.

Keywords

References

  1. ASME Boiler and Pressure Vessel Code, Scetion III, Division1 ASME
  2. ASME Boiler and Pressure Vessel Code, Section XI ASME
  3. EPRI Report, NP-4690 Evaluation of flaws in austenitic steel piping D. M. Norris(et al.)
  4. EPRI Report, NP-6045 Evaluation of flaws in austenitic steel piping D. M. Norris(et al.)
  5. USNRC Report, NUREG/CR-4082 Degraded piping program-Phase II G.M. Wilkowski(et al.)
  6. BMI Report International piping integrity research group-Final Report G.M. Wilkowski(et al.)
  7. USNRC Report, NUREG/CR-6298 Fracture behavior of short circumferentially surface-cracked pipe G.M. Wilkowski(et al.)
  8. CEGB Report, R/H/R6-Rev 3 Assessment of the integrity of structures containing defects I. Milne(et al.)
  9. Journal of Pressure Vessel Technology v.112 no.3 Validation of the deformation plasticity failure assessment diagram (DPFAD) approach-the case of an axial flaw in a pressurized cylinder J.M. Bloom
  10. ASME winter annual meeting Extension of the failure assessment diagram approach semi-elliptical flaw in pressurized cylinder J. M. Bloom
  11. ASTM STP 668 The theory of instability of the tearing mode of elastic-plastic crack growth P.C. Paris;H. Tada;A. Zahoor;H. Emst
  12. ASTM STP 668 Stability analysis of J-controlled crack growth J.W. Hutchinson;P.C. Paris
  13. EPRI Report, NP-1931 An engineering approach for elastic-plastic fracture analysis, General Electric company corporate research and development V. Kumer(et al.)
  14. EPRI Report, NP-2431 Procedure for the assessment of the integrity of nuclear pressure vessels and piping containing defects J.M. Bloom;S.N. Malik
  15. USNRC Report, NUREG/CR-4872 Experimental and analytical assessment of circumferentially surface-cracked pipes under bending P.M. Scott;J. Ahmad
  16. Proceeding of ASME PVP Conference A predictive J-estimation method for circumferentially surface-cracked pipes of power-low hardening material in pure bending, in advanced in fracture and fatigue for the 1990's-load history effects of fracture resistance J. Ahmad(et al.)
  17. Nuclear Engineering and Design v.106 no.2 Estimation of the ductile unstable fracture of pipe with a circumferential surface crack subject to bending D. Sturm(et al.)
  18. Nuclear Engineering and Design v.III A statistical based circumferentially cracked pipe fracture mechanics analysis for design or code implementation G.M. Wilkowski;P.M. Scott
  19. Trans. ASME, journal of Pressure Vessel Technology v.106 no.4 Some considerations on estimation of energy release rates for circumferentially cracked pipe J. Pan
  20. Journal of Engineering Materials and Technology v.114 no.3 Analysis of part through-wall crack in a pipe under combined tension and bending A. Zahoor
  21. Engineering Fracture Mechanics v.43 no.3 A estimation method for evaluating energy release rates of circumferential through-wall cracked pipe welds S. Rahman;F. Brust
  22. Trans. ASME, Journal of Pressure Vessel Technology v.114 no.4 Elastic-plastic fracture of circumferential through-wall cracked pipe welds subject to bending S. Rahman;F. Brust
  23. Trans. ASME, Journal of Pressure Vessel Technology v.112 no.3 Static and dynamic analysis of flaw stability in piping systems D.F. Quinones(et al.)
  24. Trans. ASME, Journal of Pressure Vessel Technology v.103 no.4 A Plastic fracture mechanics prediction for fracture instability in circumferentially cracked pipe in bending-Part I J-integral analysis A. Zahoor;M.F. Kanninen
  25. Nuclear Engineering and Design v.127 no.1 Approximate fracture methods for pipes-Part I : Theory P. Gilles;F. Brust
  26. Nuclear Engineering and Design v.127 no.1 Approximate fracture methods for pipes-Part II : Application P. Gilles;F. Brust
  27. Journal of Applied Mechanics v.50 no.1 Circumferentially through-wall crack in a cylindrical shell under combined bending and tension J.L. Sanders Jr.
  28. Journal of Applied Mechanics v.49 Circumferentially through-wall crack in a cylindrical she;; under tension J.L. Sanders Jr.
  29. Engineering Fracture Mechanics v.18 no.5 Crack opening areas in pressure vessels and pipes C. Wuthrich
  30. Trans. ASME, Journal of Pressure Vessel Technology v.103 no.2 Ductile fracture of pipes and cylindrical containers with a circumferential flaw F. Edrogan;F. Deale