Nuclear Engineering and Technology

  • 제32권4호
  • /
  • Pages.410-423
  • /
  • 2000
  • /
  • 1738-5733(pISSN)
  • /
  • 2234-358X(eISSN)
한국원자력학회 (Korean Nuclear Society)
권호 표지

Two Dimensional Analysis for the External Vessel Cooling Experiment

  • Yoon, Ho-Jun (Seoul National University) ;
  • Kune Y. Suh (Seoul National University)
  • 발행 : 2000.08.01
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

A two-dimensional numerical model is developed and applied to the LAVA-EXV tests performed at the Korea Atomic Energy Research Institute (KAERI) to investigate the external cooling effect on the thermal margin to failure of a reactor pressure vessel (RPV) during a severe accident. The computational program was written to predict the temperature profile of a two-dimensional spherical vessel segment accounting for the conjugate heat transfer mechanisms of conduction through the debris and the vessel, natural convection within the molten debris pool, and the possible ablation of the vessel wall in contact with the high temperature melt. Results of the sensitivity analysis and comparison with the LAVA-EXV test data indicated that the developed computational tool carries a high potential for simulating the thermal behavior of the RPV during a core melt relocation accident. It is concluded that the main factors affecting the RPV failure are the natural convection within the debris pool and the ablation of the metal vessel, The simplistic natural convection model adopted in the computational program partly made up for the absence of the mechanistic momentum consideration in this study. Uncertainties in the prediction will be reduced when the natural convection and ablation phenomena are more rigorously dealt with in the code, and if more accurate initial and time-dependent conditions are supplied from the test in terms of material composition and its associated thermophysical properties.

키워드

참고문헌

  1. K. H. Kang et al., 'A Feasibility Experiment for Assessing the Efficacy of Ex-Vessel Cooling through the External Gap Structure,' Proc. of the Korean Nuclear Society Spring Meeting, Pohang, Korea, May 28-29 (1999)
  2. J. E. O'Brien and G.L. Hawkes, 'Thermal Analysis of a Reactor Lower Head with Core Relocation and External Boiling Heat Transfer,' AIChE Symposium Series, 87, 283, 159 (1991)
  3. H. J. Park and V. K. Dhir, 'Effect of Outside Cooling on the Thermal Behavior of a Pressurized Water Reactor Vessel Lower Head,' Nuclear Technology, 100, 331 (1992)
  4. F. Mayinger, M. Jahn, H. H. Reineke and U. Steinberner, 'Examination of Thermohydraulic Process and Heat Transfer in a Core Melt,' Final report BMFT RS 48/1, Technical University, Hannover, Germany (1975)
  5. R. E. Henry et al., 'Cooling of Core Debris within the Reactor Vessel Lower Head,' Nuclear Technology, 101, 385 (1993)
  6. Private Communication from K. H. Kang, Korea Atomic Energy Research Institute, to H. J. Yoon, Seoul National University, October (1999)
  7. M. S. El-Genk et al., 'Transient Heat Conduction During Quenching of Downward Facing Copper and Stainless Steel Convex Surfaces,' J. Numerical Heat Transfer Part A, 29, 543 (1996) https://doi.org/10.1080/10407789608913806
  8. H. J. Yoon and K. Y. Suh, 'Sensitivity Studies on Thermal Margin of Reactor Vessel Lower Head During A Core Melt Accident,' Proc. of the 8th International Conference on Nuclear Engineering (ICONE 8), Baltimore, MD, USA, April 2-6 (2000)
  9. F. J. Asfia and V. K. Dhir, 'An Experimental Study of Natural Convection in a Volumetrically Heated Spherical Pool with Rigid Wall,' Int. Mechanical Engineering Congress & the Winter Annual Meeting, Chicago, IL, USA, November 6-11 (1994)
  10. T. G. Theofanous et al., 'In-vessel Coolability and Retention of a Core Melt,' DOE/ID-10460, vol. 1, U.S. Department of Energy, Washington, DC, USA (1995)
  11. H. J. Park, V. K. Dhir and W. E. Kastenberg, 'Effect of External Cooling on the Thermal Behavior of a Boiling Water Reactor Vessel Lower Head,' Nuclear Technology, 108, 266-282 (1994)
  12. K. Y. Suh and R. E. Henry, 'Integral Analysis of Debris Material and Heat Transport in Reactor Vessel,' Nuclear Engineering and Design, 151, 203-221 (1994) https://doi.org/10.1016/0029-5493(94)90043-4
  13. M. Jahn and H. H. Reineke, 'Free Convection Heat Transfer with Internal Heat Sources,' Proc. of the Fifth Int. Heat Transfer Conference, 3, 74 (1974)
  14. FLUENT 4.32 User's Guide, FLUENT Inc., Lebanon, NH, USA, January (1995)
  15. H. J. Yoon K. Y. Suh and H. K. Kim, 'Estimation of Thermal Margin for External Cooling of Lower Head,' Trans. of the ANS Annual Meeting and Embedded Topical Meeting, Boston, MA, USA, June 6-10 (1999)