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RELATIONSHIP BETWEEN RADIATION INDUCTED YIELD STRENGTH INCREMENT AND CHARPY TRANSITION TEMPERATURE SHIFT IN REACTOR PRESSURE VESSEL STEELS OF KOREAN NUCLEAR POWER PLANTS

  • Received : 2011.04.06
  • Accepted : 2011.08.05
  • Published : 2012.06.25

Abstract

The decrease in the fracture toughness of ferritic steels in a reactor pressure vessel is an important factor in determining the lifetime of a nuclear power plant. A surveillance program has been in place in Korea since 1979 to assess the structural integrity of RPV steels. In this work, the surveillance data were collected and analyzed statistically in order to derive the empirical relationship between the embrittlement and strengthening of irradiated reactor pressure vessel steels. There was a linear relationship between the yield strength change and the transition temperature shift change at 41 J due to irradiation. The proportional coefficient was about $0.5^{\circ}C$/MPa in the base metals (plate/forgings). The upper shelf energy decrease ratio was non-linearly proportional to the yield strength change, and most of the data lay along the trend curve of the US results. The transition regime temperature interval, ${\Delta}T_T$, was less than the US data. The overall change from irradiation was very similar to the US results. It is expected that the results of this study will be applied to basic research on the multiscale modeling of the irradiation embrittlement of RPV materials in Korea.

Keywords

References

  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. 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).
  3. ASTM Standards, "Standards Test Methods and Definitions for Mechanical Testing of Steel Products", ASTM A370-92, American Society for Testing and Materials (1993).
  4. ASTM Standards, "Standards Test Methods for Notched Bar Impact Testing of Metallic Materials", ASTM E23-91a, American Society for Testing and Materials (1993).
  5. J. F. Perrin, R. A. Wullaert, G. R. Odette, and P. M. Lombrozo, "Physically Based Regression Correlations of Embrittlement Data from Reactor Pressure Surveillance Programs," EPRI NP-3319, Electric Power Research Institute (1984).
  6. J. D. Varsik, S. M. Schloss, and J. J. Koziol, "Evaluation of the Irradiation Response of Reactor Pressure Vessel Materials," EPRI NP-2720, Electric Power Research Institute (1982).
  7. M. A., Sokolov and R. K. Nanstad, "Comparison of Irradiation-induced shifts of KJc and Charpy impact toughness for reactor pressure vessel steels," ASTM Special Technical Publication, Issue 1325, pp. 167-190, (1999).
  8. E. D. Eason, G. R. Odette, R. K. Nanstad, and T. Yamamoto, "A Physically Based Correlation of Irradiation-Induced Transition Temperature Shifts for RPV Steels," ORNL/TM-2006/530, Oak Ridge National Laboratory (2007).
  9. N. Soneda and A. Nomoto, "Characteristics of the New Embrittlement Correlation Method for the Japanese Reactor Pressure Vessel Steels," 17th International Conference on Nuclear Engineering, Brussels, Belgium, pp.423-430, Jul. 12-16, 2009.
  10. R. K. Nanstad, M. A. Sokolov, and D. E. McCabe, "Applicability of the facture toughness master curve to irradiated highly embrittled steel and intergranular fracture," J. of ASTM Inter., vol. 5, pp. 1-18 (2008).
  11. G. R. Odette, P. M. Lombrozo, and R. A. Wullaert, "Relationship Between Irradiation Hardening and Embrittlement of Pressure Vessel Steels," 12th International Symposium of the Effects of Radiation on Materials, ASTM STP 870, pp. 840-860, American Society for Testing and Materials, Philadelphia (1985).
  12. W. Oldfield, P. McConnell, W. Server, and E. Oldfield, "Irradiated Pressure Vessel Steel Data Base," EPRI NP-2428, Electric Power Research Institute (1982).
  13. J. T. Buswell, "A Comparison of Reactor Surveillance and Materials Test Reactor Data on Radiation Embrittlement of Water Reactor Pressure Vessel Steels," CEGB-TPRD/B /0351/N83, British Central Electricity Generating Board (1983).
  14. W. J. Stelzman and R. G. Berggren, "Radiation Strengthening and Embrittlement in Heavy-Section Plates and Welds," ORNL-4871, Oak Ridge National Laboratory (1973).
  15. J. R. Hawthorne, "Postirradiation Dynamic Tear and Charpy-V Performance of 12-in. Thick A533-B Steel Plates and Weld Metal," Nuclear Engineering and Design, 17, 116 (1971). https://doi.org/10.1016/0029-5493(71)90044-6
  16. F. A. Nichols, "Theory of Radiation Embrittlement and Recovery of Radiation Damage in Ferritic Steels," Philosophical Magazine, 14, 335 (1966). https://doi.org/10.1080/14786436608219016
  17. M. Galliani, N. Benatti, V. Guerrieri, I. Leonardo, and A. Pulianchi, "Garigliano Nuclear Power plant Pressure Vessel Surveillance Program-7th Cycle," DPT/SN/041/R/79, Italian Commission for Electric Energy, Division of Production and Transmission, Nuclear Section, (1979).
  18. W. Oldfield, ASTM Standardization News, 3(11), 24 (1975).
  19. J. Eisenhauer, "Regression through the origin," Teaching Statistics, vol. 25, pp.76-80 (2003). https://doi.org/10.1111/1467-9639.00136
  20. J. Kwon, G.-G. Lee, and C. Shin, "Multiscale Modeling of Radiation Effects on Materials: Pressure Vessel Embrittlement," Nucl. Eng. Technol., vol. 41, pp.1-20, (2009). https://doi.org/10.5516/NET.2009.41.1.001