Integrity Evaluation of Ice Plugged Pipes Applied on Short Jacket

  • Published : 2002.04.01

Abstract

In special industrial fields such 3s nuclear power plants and chemical plants, it is often necessary to repair system components without plant shutdown or drainage of system having many piping structures which may have hazardous or expensive fluid. A temporary ice plugging method for blocking internal flow is considered as a useful method in that case. According to the pipe freezing guideline of the nuclear power plant, the length of a freezing jacket must be longer than twice of the pipe diameter. However, for applying the ice plugging to short pipes which do not have enough freezing length because of geometrical configuration, it is inevitable to use shorter jacket less than twice of the pipe diameter. In this study, the integrity evaluation for short pipes in the nuclear power plant Is conducted by an experiment and the finite element analysis. From the results, the ice plugging process in short pipes can be safely carried out without any plastic deformation and fracture.

Keywords

References

  1. M.T. Flaman and N.N. Shah, 'Structural Integrity Investigation of Ice Plugging Procedure on Feeder Pipe,' Ontario Hydro Research Division, (1985)
  2. Y.D. Park, S.K. Byun and B.S. Kang, 'Thermal Deformation and Thermal Stress Analysis of Pipe During Pipe Internal Fluid Freezing,' KSME, pp227-237, (1998)
  3. Y.D. Park, M.W. Lee, T.W. Ku, K.W. Kim and B.S. Kang, 'Experimental Evaluation on the Thermal Stress Due to Ice Plugging of Tubes in Nuclear Power Plant,' KSME, pp.1094-1103, (1999)
  4. NP-6384D, Freeze Sealing(Plugging) of Piping, A Guide for Nuclear Plwer Plant Maintenance Personnel, (1989)
  5. ANSYS Inc., Structural Analysis Guide, release 5.5, (1998)
  6. Crocker & King, McGRAW HILL, Piping Handbook, (1980)
  7. F.P. Incropera and D.P. Dewitt, Fundamentals of Heat and Mass Transfer, 4th edition, John Wiley & Sons, (1996)
  8. American Society of Mechanical Engineers, ASME Boiler and Pressure Vessel Code Section XI, (1995)
  9. NP-6045 Research Project 1757-65, Evaluation of Flaws in Ferritic Piping, (1988)
  10. Y.J. Kim, C.S. Seok, H.K. Jun, Y.H. Choi and J.B. Lee, 'Development of Nuclear piping Integrity Expert System(Ⅰ),' KSME 20. pp.575-584, (1996)
  11. NPIES ver 2.0., Nuclear Piping Integrity Expert System
  12. Y. Murakami, Stress Intensity Factors Handbook Copy, volume 2
  13. T.L. Anderson, Fracture Mechanics Fundmentals and Application, CRC Press, (1995)
  14. D.S. Chawla, S.R. Bhate and H.S. Kushwaha, 'Numerical simulation of crack growth and arrest in a vessel under pressure thermal shock,' International Journal of Pressure Vessels and Piping 77, pp.261-271, 2000 https://doi.org/10.1016/S0308-0161(00)00004-1
  15. X. Wang and S.B. Lambert, 'Stress intensity factors and weight functions for longitudinal semi-elliptical surface cracks in thin pipes,' International Journal of Pressure Vessels and Piping 65, pp.75-87, (1996) https://doi.org/10.1016/0308-0161(94)00160-K
  16. I.H. Kwon and S.H. Chung, 'A Study on the Fracture Toughness Evaluating Method for Cryogenic Structural Material,' KSME 22-1, pp. 64-72, (1998)
  17. Baumeister, T. and Marks, L.S., Standard Handbook for Mechanical Engineers, McGraw-Hill (1967)
  18. NRC Bulletin 88-11, 'Pressurizer surge line thermal stratification', (1988)