DOI QR코드

DOI QR Code

ENHANCEMENT OF DRYOUT HEAT FLUX IN A DEBRIS BED BY FORCED COOLANT FLOW FROM BELOW

  • Received : 2009.03.05
  • Accepted : 2010.05.06
  • Published : 2010.06.30

Abstract

In the design of advanced light water reactors (ALWRs) and in the safety assessment of currently operating nuclear power plants, it is necessary to evaluate the possibility of experiencing a degraded core accident and to develop innovative safety technologies in order to assure long-term debris cooling. The objective of this experimental study is to investigate the enhancement factors of dryout heat flux in debris beds by coolant injection from below. The experimental facility consists mainly of an induction heater, a double-wall quartz-tube test section containing a steel-particle bed and coolant injection and recovery condensing loop. A fairly uniform heating of the particle bed was achieved in the radial direction and the axial variation was within 20%. This paper reports the experimental data for 3.2 mm and 4.8 mm particle beds with a 300 mm bed height. The dryout heat density data were obtained for both the top-flooding and the forced coolant injection from below with an injection mass flux of up to $1.5\;kg/m^2s$. The dryout heat density increased as the rate of coolant injection increased. At a coolant injection mass flux of $1.0\;kg/m^2s$, the dryout heat density was ${\sim}6.5\;MW/m^3$ for the 4.8 mm particle bed and ${\sim}5.6\;MW/m^3$ for the 3.2 mm particle bed. The enhancement factors of the dryout heat density were 1.6-1.8.

Keywords

References

  1. Hohmann. H. et al., "FCI Experiments in Corium/Water System," Nucl. Eng. Des., 177, p. 339-349 (1997). https://doi.org/10.1016/S0029-5493(97)00202-1
  2. Farmer, M. T. et al., "Results of MACE Test M0 and M1," Proceedings of the 2nd OECD (NEA) CSNI Specialist's Meeting on Molten Core Debris-Concrete Interactions, Karlsruhe, Germany (1992).
  3. Alsmeyer, H. and Tromm, W., "The COMET Concept for Cooling Core Melts: Evaluation of the Experimental Studies and Use in the EPR," FZKA 6186, EXV-CSC(99)- D036 (1999).
  4. Klockow, H. B. et al., "Simulant Melt Pool Quench Behavior via Coolant Injection from Below," Proc. 10th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea (2003).
  5. Barleon, L. et al., "Cooling of Debris Beds," Nuclear Technology, 65, pp. 67-86 (1984). https://doi.org/10.13182/NT84-A33374
  6. Hu, K. and Theofanous, T. G., "On the Measurement and Mechanism of Dryout in Volumetrically Heated Coarse Particle Beds," Int. J. Multiphase Flow, 17(4), pp. 519- 532 (1991). https://doi.org/10.1016/0301-9322(91)90047-7
  7. Tsai, F. P. and Catton, I., "On Dryout Heat Flux and Pressure Drop of a Submerged Inductively Heated Bed Flow From Below," Proc. Nat. Heat Transfer Conf., AIChe Symposium Series, 79(225), pp. 296-302 (1983).
  8. Cha, J. H. et al., "Forced Flow Dryout Heat Flux in Heat Generating Debris Bed," J. Korean Nuclear Society, 18(4), pp. 273-280 (1986).
  9. Atkhen, K. and Berthoud, G., "Experimental and Numerical Investigations on Debris Bed Coolability in a Multidimensional and Homogeneous Configuration with Volumetric Heat Source," Nuclear Technology, 142, pp. 270-282 (2003). https://doi.org/10.13182/NT03-A3389
  10. Schafer, P., Groll, M., and Kulenovic, R., "Basic investigations on debris cooling," Nucl. Eng. Des, 236, pp. 2104-2116 (2006). https://doi.org/10.1016/j.nucengdes.2006.03.033
  11. Lindholm, I. et al., "Dryout heat flux experiments with deep heterogeneous particle bed," Nucl. Eng. Des, 236, pp. 2060-2074 (2006). https://doi.org/10.1016/j.nucengdes.2006.03.036
  12. Lipinski, R. J., "A Coolability Model for Postaccident Nuclear Reactor Debris," Nuclear Technology, 65, pp. 53- 66 (1984). https://doi.org/10.13182/NT84-A33373
  13. Turland, B. D. and Moore, K., "Debris Bed Heat Transfer with Top and Bottom Cooling," Proc. Nat. Heat Transfer Conf., AIChe Symposium Series, 79(225), pp. 250-255 (1983).
  14. Kim, S. H., "A Modeling of the Liquid-Vapor Flow in a Self-Heated Porous Medium: With Application to the Dryout Limits," J. Nuclear Science and Technology, 33(9), pp. 686-695 (1996). https://doi.org/10.3327/jnst.33.686
  15. Burger, M. and Berthoud, G., "Basic laws and coolability of particulate debris: comments on the status and present contributions," Nucl. Eng. Des, 236, pp. 2049-2059 (2006). https://doi.org/10.1016/j.nucengdes.2006.03.026