Two and Three-Dimensional Analysis Comparison of Nozzles due to Internal Pressure, Thermal Load and External Load

내부압력, 열하중 및 외부하중을 고려한 노즐의 2차원 및 3차원 해석 비교

  • Yoon, Hyo-Sub (NSSS Division, KEPCO Engineering and Construction Company) ;
  • Kim, Jong-Min (NSSS Division, KEPCO Engineering and Construction Company) ;
  • Maeng, Cheol-Soo (NSSS Division, KEPCO Engineering and Construction Company) ;
  • Kim, Hyun-Min (NSSS Division, KEPCO Engineering and Construction Company) ;
  • Lee, Dae-Hee (NSSS Division, KEPCO Engineering and Construction Company)
  • 윤효섭 (한국전력기술주식회사 원자로설계개발단) ;
  • 김종민 (한국전력기술주식회사 원자로설계개발단) ;
  • 맹철수 (한국전력기술주식회사 원자로설계개발단) ;
  • 김현민 (한국전력기술주식회사 원자로설계개발단) ;
  • 이대희 (한국전력기술주식회사 원자로설계개발단)
  • Received : 2015.03.06
  • Accepted : 2015.05.09
  • Published : 2015.06.30


In this paper, the two-dimensional(2D) and three-dimensional(3D) analyses have been performed in order to evaluate the structural integrities and compare 2D and 3D results for nozzles attached to cylindrical shells. Three nozzles, which are currently used in the nuclear power plant, are chosen to evaluate the structural integrities, and each nozzle is subjected to internal pressure, temperature variation and external loads. It is found that the 2D analysis for internal pressure should be performed with a factor of more than 1.5 or a stress concentration factor; 2D and 3D analysis results for temperature variation are almost similar to each other regardless of cladding; and the analysis results for external loads by WRC Bulletin 297 are more conservative than the 3D analysis results.

본 논문에서는 원통형 쉘에 부착된 노즐의 구조 건전성평가를 수행하고 그 결과를 비교하기 위해 2차원(2D)과 3차원(3D) 해석이 수행되었다. 현재 원자력 발전소에서 사용되는 3개의 노즐을 구조 건전성평가를 위해 선정하였고, 각각 노즐은 내부압력, 온도변화 및 외부하중을 받는다. 내부압력에 대한 2D 해석은 1.5이상의 계수 값을 이용하거나 응력집중 계수를 적용하여야 하고, 온도변화에 대한 2D와 3D 해석결과는 피복재의 유무와 상관없이 서로 거의 비슷하며, 외부하중에 대한 WRC Bulletin 297에 의한 해석결과는 3D 해석결과보다 더 보수적임을 확인할 수 있었다.



Supported by : 한국에너지기술평가원(KETEP)


  1. American Society of Mechanical Engineers (1998 Edition with 1999, 2000 Addenda) ASME Boiler and Pressure Vessel Code-An International Code, Section II, Part D and Section III, Division 1-Subsection NB.
  2. ANSYS Finite Element Program (2014) ANSYS Mechanical APDL, Version 15.0, ANSYS Inc..
  3. Sommerville, D., Walter, M. (2011) An Investigation into the Effects of Modelling Cylindrical Nozzle to Cylindrical Vessel Intersections Using 2D Axisymmetric Finite Element Models and a Preposed Method for Correcting the Results, Proceedings of the ASME 2011 Pressure Vessels & Piping Division Conference, PVP2011-57001, Baltimore.
  4. Lee, H.S., Ha, C.H., Park, T.J. (2011) Finite Element Analysis for Nozzle with External Loads, Proceedings of the ASME 2011 Pressure Vessels & Piping Division Conference, PVP2011-57407, Baltimore.
  5. Mershon, J.L., Mokhtarian, K., Ranjan, G.V., Rodabaugh, E.C. (1987) Welding Research Council Bulletin 297 - Local Stresses in Cylindrical Shells due to External Loadings on Nozzles-Supplement to WRC Bulletin No.107-(Revision I), Welding Research Council, Inc., New York, p.88.
  6. Conway, L.E., Harkness, A.W. (2013) Instrumentation and Control Penetration Flange for Pressurized Water Reactor, United States Patent Application Publication US 2013/0287157 A1.
  7. Walter, M.C., Sommerville, D.V. (2010) Nozzle Blend Radius Peak Stress Correction Factors For 2-D Axisymmetric Finite Element Models, Proceedings of the ASME 2010 Pressure Vessels & Piping Division / K-PVP Conference, PVP2010-25104, Washington.
  8. Johnson, R.E., Anderson, P.L., Han, S.B. (1989) A Comparison of Finite Element Methods for Determining Stress Industrial in Reactor Vessel Nozzles, Proceedings of the 4th KAIF/KNS Annual Conference, Korea Atomic Industrial Forum, Inc..
  9. Timoshenko, S.P., Krieger, S.W. (1959) Theory of Plates and Shells, McGraw-Hill Book Company, second edition, Singapore, p.580.
  10. Lee, Y.J., Kim, J.M., Kim, H.M., Lee, D.H., Chung, C.K. (2014) Structural Integrity Evaluation of Reactor Pressure Vessel Bottom Head without Penetration Nozzles in Core Melting Accident, J. Comput. Struct. Eng. Inst. Korea, 27(3), pp.191-198.