Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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NUMERICAL ANALYSIS OF THERMAL STRATIFICATION IN THE UPPER PLENUM OF THE MONJU FAST REACTOR

  • Received : 2012.08.09
  • Accepted : 2012.11.01
  • Published : 2013.04.25
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Abstract

A numerical analysis of thermal stratification in the upper plenum of the MONJU fast breeder reactor was performed. Calculations were performed for a 1/6 simplified model of the MONJU reactor using the commercial code, CFX-13. To better resolve the geometrically complex upper core structure of the MONJU reactor, the porous media approach was adopted for the simulation. First, a steady state solution was obtained and the transient solutions were then obtained for the turbine trip test conducted in December 1995. The time dependent inlet conditions for the mass flow rate and temperature were provided by JAEA. Good agreement with the experimental data was observed for steady state solution. The numerical solution of the transient analysis shows the formation of thermal stratification within the upper plenum of the reactor vessel during the turbine trip test. The temporal variations of temperature were predicted accurately by the present method in the initial rapid coastdown period (~300 seconds). However, transient numerical solutions show a faster thermal mixing than that observed in the experiment after the initial coastdown period. A nearly homogenization of the temperature field in the upper plenum is predicted after about 900 seconds, which is a much shorter-term thermal stratification than the experimental data indicates. This discrepancy may be due to the shortcoming of the turbulence models available in the CFX-13 code for a natural convection flow with thermal stratification.

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References

  1. R. Vidil, D. Grand and F. Leroux, "Interaction of Recirculation and Stable Stratification in a Rectangular Cavity Filled with Sodium," Nucl. Eng. Des., vol. 105, pp.321- 332 (1988). https://doi.org/10.1016/0029-5493(88)90253-1
  2. Y. Ieda, I. Maekawa, T. Muramatsu and S. Nakanish, "Experimental and Analytical Studies of the Thermal Stratification Phenomenon in the Outlet Plenum of Fast Breeder Reactors," Nucl. Eng. Des., vol. 120, pp. 403-414 (1990). https://doi.org/10.1016/0029-5493(90)90390-J
  3. N. Tanaka, S. Moriya, S. Ushijima, T. Koga and Y. Eguchi, "Prediction Method for Thermal Stratification in a Reactor Vessel," Nucl. Eng. Des., vol. 120, pp. 395-402 (1990). https://doi.org/10.1016/0029-5493(90)90389-F
  4. T. Muramatsu and H. Ninokata, "Investigation of Turbulence Modeling in Thermal Stratification Analysis," Nucl. Eng. Des., vol.150, pp. 81-93 (1994). https://doi.org/10.1016/0029-5493(94)90053-1
  5. Y. Doi, and T. Muramatsu, "Numerical Analysis of Thermal Stratification Phenomena in Upper Plenum of Fast Breeder Reactor," Proc. of 8th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics, Kyoto, Japan, 1997.
  6. K. Hanjalic, "One-Point Closure Models for Buoyancy- Driven Turbulent Flows," Annu. Rev. Fluid Mech., vol. 34, pp. 321-347 (2002). https://doi.org/10.1146/annurev.fluid.34.082801.161035
  7. S. K. Choi and S. O. Kim, "Turbulence Modeling of Natural Convection in Enclosures: A Review," J. Mech. Science Tech., vol. 26, pp. 283-297 (2012). https://doi.org/10.1007/s12206-011-1037-0
  8. N. Z. Ince and B. E. Launder, "On the Computation of Buoyancy-Driven Turbulent Flows in Rectangular Enclosures," Int. J. Heat Fluid Flow, vol. 10, pp. 110-117 (1989). https://doi.org/10.1016/0142-727X(89)90003-9
  9. S. K. Choi and S. O. Kim, "Treatment of Turbulent Heat Fluxes with the Elliptic-Blending Second-Moment Closure for Turbulent Natural Convection Flows," Int. J. Heat Mass Transfer, vol. 51, pp. 2377-2388 (2008). https://doi.org/10.1016/j.ijheatmasstransfer.2007.08.012
  10. M. Pellegrini, H. Endo, E. Merzari and H. Nonokata, "Algebraic Turbulent Heat Flux Model for Prediction of Thermal Stratification in Piping System," Proc. of 8th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics, Toronto, Canada, September 25-30, 2011.
  11. H. C. Chen and V. C. Patel, "Near-wall Turbulence Models for Complex Flows Including Separation," AIAA J., vol. 26, pp. 641-648 (1988). https://doi.org/10.2514/3.9948
  12. F. R. Menter, "Two Equation Eddy-Viscosity Turbulence Models for Engineering Applications," AIAA J., vol. 32, pp.1598-1604 (1994). https://doi.org/10.2514/3.12149
  13. G. Medic and P. A. Durbin, "Toward Improved Prediction of Heat Transfer on Turbine Blades," ASME, J. Turbomach., vol. 124, pp. 187-192 (2002). https://doi.org/10.1115/1.1458020
  14. R. Manceau and K. Hanjalic, "Elliptic Blending Model : A New Near-Wall Reynolds-Stress Turbulence Closure," Phys. Fluids, vol. 14, pp. 744-754 (2002). https://doi.org/10.1063/1.1432693
  15. JAEA FBR Plant Technology Unit, "Data description for Numerical Analyses of Sodium Natural Convection in the Upper Plenum of the MONJU Reactor Vessel" Presented at the First (Kick-off) Research Coordination Meeting (RCM) of the IAEA Coordinated Research Project (CRP) on Benchmark Analyses of Sodium Natural Convection in the Upper Plenum of the MONJU Reactor Vessel, IAEA Headquarters, Vienna (2008).
  16. JAEA FBR Plant Technology Unit, "Complementary Descriptions for Detailed Boundary Conditions," Presented at the First (Kick-off) Research Coordination Meeting (RCM) of the IAEA Coordinated Research Project (CRP) on Benchmark Analyses of Sodium Natural Convection in the Upper Plenum of the MONJU Reactor Vessel, IAEA Headquarters, Vienna (2008).
  17. T. Sofu, J. Thomas and T. Fanning, "Analysis of Thermal Stratification in the Upper Plenum of the MOJU Reactor Vessel Using a Simplified Model," Presentation at the Second RCM of the IAEA CRP on "Benchmark Analysis of MONJU Natural Convection", Marcoule, France (2009).
  18. V. Blind, U. Bieder and T. Sofu, "Benchmark Analysis of Sodium Natural Convection in the Upper Plenum of the MONJU Reactor Vessel - Preparation of a Simplified Model for the Upper Core Structure," CEA Report. DEN/CAD/ DER /SSTH/LMDL/NT/2009-105A, (2009).
  19. T. Sofu, "Parametric Analysis of Thermal Stratification during the Monju Turbine Trip Test," Proceedings of ICAPP '12 Chicago, USA, June 24-28, Paper 12259 (2012).

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