DOI QR코드

DOI QR Code

Statistical analysis on the fluence factor of surveillance test data of Korean nuclear power plants

  • Lee, Gyeong-Geun (Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Kim, Min-Chul (Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Yoon, Ji-Hyun (Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Lee, Bong-Sang (Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Lim, Sangyeob (Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Kwon, Junhyun (Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute)
  • 투고 : 2016.09.28
  • 심사 : 2017.02.08
  • 발행 : 2017.08.25

초록

The transition temperature shift (TTS) of the reactor pressure vessel materials is an important factor that determines the lifetime of a nuclear power plant. The prediction of the TTS at the end of a plant's lifespan is calculated based on the equation of Regulatory Guide 1.99 revision 2 (RG1.99/2) from the US. The fluence factor in the equation was expressed as a power function, and the exponent value was determined by the early surveillance data in the US. Recently, an advanced approach to estimate the TTS was proposed in various countries for nuclear power plants, and Korea is considering the development of a new TTS model. In this study, the TTS trend of the Korean surveillance test results was analyzed using a nonlinear regression model and a mixed-effect model based on the power function. The nonlinear regression model yielded a similar exponent as the power function in the fluence compared with RG1.99/2. The mixed-effect model had a higher value of the exponent and showed superior goodness of fit compared with the nonlinear regression model. Compared with RG1.99/2 and RG1.99/3, the mixed-effect model provided a more accurate prediction of the TTS.

키워드

참고문헌

  1. IAEA, Integrity of Reactor Pressure Vessels in Nuclear Power Plants: Assessment of Irradiation Embrittlement Effects in Reactor Pressure Vessel Steels, IAEA Nuclear Energy Series No. NP-T-3.11, International Atomic Energy Agency, 2009.
  2. ASTM Standards E23-93, Standards Test Methods for Notched Bar Impact Testing of Metallic Materials, 1993, ASTM E23-91a, American Society for Testing and Materials, 1993.
  3. ASTM Standards E8/E8M-13, Standard Test Methods for Tension Testing of Metallic Materials, 2013.
  4. ASTM Standards 185-82, Standard Practice for Design of Surveillance Programs for Light-Water Moderated Nuclear Power Reactor Vessels, 1982.
  5. U.S. Nuclear Regulatory Commission, Regulatory Guide 1.99 Revision 2, 1988.
  6. U.S. Nuclear Regulatory Commission, LWR Pressure Vessel Surveillance Dosimetry Improvement Program (NUREG/CR-3391), 1983.
  7. Electric Power Research Institute, Physically Based Regression Correlations of Embrittlement Data from Reactor Pressure Vessel Surveillance Programs (EPRI NP-3319), 1984.
  8. U.S. Nuclear Regulatory Commission, 10 CFR 50.61a Alternate Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events, 2010.
  9. E.D. Eason, G.R. Odette, R.K. Nanstad, T. Yamamoto, A physically based correlation of irradiation-induced transition temperature shifts for RPV steels, J. Nucl. Mater 433 (2013) 240-254. https://doi.org/10.1016/j.jnucmat.2012.09.012
  10. K.O. Chang, Final Report for the 5th Surveillance Test of the Reactor Pressure Vessel Material (Capsule P) of Kori Nuclear Power Plant Unit 1, KAERI/CR-93/2000, Korea Atomic Energy Research Institute, 2000.
  11. The R Foundation for Statistical Computing, R: A Language and Environment for Statistical Computing [Internet], Vienna, Austria, 2016. Available from: https://www.R-Project.org (Accessed 18 September 2016).
  12. C. Ritz, J.C. Streibig, Nonlinear Regression with R, Springer, New York, 2008.
  13. J.C. Pinheiro, D.M. Bates, Mixed-Effects Models in S and S-Plus, Springer, York, 2000.
  14. M.J. Crawley, The R Book, second ed., John Wiley & Sons, Ltd, United Kingdom, 2013.
  15. K.P. Burnham, D.R. Anderson, Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach, second ed., Springer-Verlag, New-York, 2002, p. 63.