Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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MAJOR THERMAL-HYDRAULIC PHENOMENA FOUND DURING ATLAS LBLOCA REFLOOD TESTS FOR AN ADVANCED PRESSURIZED WATER REACTOR APR1400

  • Park, Hyun-Sik (Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Choi, Ki-Yong (Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Cho, Seok (Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Kang, Kyoung-Ho (Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute) ;
  • Kim, Yeon-Sik (Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute)
  • Received : 2010.08.02
  • Accepted : 2011.02.18
  • Published : 2011.06.25
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Abstract

A set of reflood tests has been performed using ATLAS, which is a thermal-hydraulic integral effect test facility for the pressurized water reactors of APR1400 and OPR1000. Several important phenomena were observed during the ATLAS LBLOCA reflood tests, including core quenching, down-comer boiling, ECC bypass, and steam binding. The present paper discusses those four topics based on the LB-CL-11 test, which is a best-estimate simulation of the LBLOCA reflood phase for APR1400 using ATLAS. Both homogeneous bottom quenching and inhomogeneous top quenching were observed for a uniform radial power profile during the LB-CL-11 test. From the observation of the down-comer boiling phenomena during the LB-CL-11 test, it was found that the measured void fraction in the lower down-comer region was relatively smaller than that estimated from the RELAP5 code, which predicted an unrealistically higher void generation and magnified the downcomer boiling effect for APR1400. The direct ECC bypass was the dominant ECC bypass mechanism throughout the test even though sweep-out occurred during the earlier period. The ECC bypass fractions were between 0.2 and 0.6 during the later test period. The steam binding phenomena was observed, and its effect on the collapsed water levels of the core and down-comer was discussed.

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References

  1. S. J. Cho, et al.: The Development of Passive Design Features for the Korean Next Generation Reactor, Nuclear Engineering and Design, 201, 259 (2000). https://doi.org/10.1016/S0029-5493(00)00257-0
  2. W. P. Baek, et al.: KAERI Integral Effect Test Program and the ATLAS Design, Nuclear Technology, 152, 183 (2005).
  3. W.P. Baek, et al.: LBLOCA and DVI Line Break Tests with the ATLAS Integral Facility, Nuclear Engineering and Technology, 41(6), 775-784 (2009). https://doi.org/10.5516/NET.2009.41.6.775
  4. H. S. Park, et al.: An Integral Effect Test on the Reflood Period of a Large-Break LOCA for the APR1400 Using ATLAS, Nuclear Technology, 70, 100-113 (2010).
  5. M. Ishii and I. Kataoka: Similarity Analysis and Scaling Criteria for LWRs under Single Phase and Two-Phase Natural Circulation, NUREG/CR-3267, ANL-83-32, Argonne National Laboratory, USA (1983).
  6. H. S. Park, et al.: Calculation Sheet for the Basic Design of the ATLAS Fluid System, KAERI/TR-3333/2007, KAERI, Daejeon, Korea (2007).
  7. Y. S. Kim, et al.: Commissioning of the ATLAS Thermalhydraulic Integral Test Facility, Nuclear Technology, 35, 1791-1799 (2008).
  8. S. Cho, et al.: Description of the data acquisition-control system and instrumentation of the ATLAS test facility, Proceedings of WORTH-3 (The 3rd Sino-Korea Workshop In Nuclear Reactor Thermal Hydraulics), Aug. 22-24, Chengdu, China (2007).
  9. H.S. Park, D.J. Euh, K.Y. Choi, et al., "Pre-Test Analysis of a Large-Break LOCA for the ATLAS Facility," Proceedings of the NURETH-11, Avignon, France, October 2-6 (2005).
  10. K.Y. Choi, et al.: Experimental Simulation of a Direct Vessel Injection Line Break of the APR1400 with the ATLAS, Nuclear Engineering and Technology, 41(5), 655-676 (2009). https://doi.org/10.5516/NET.2009.41.5.655
  11. U.S. NRC: Compendium of ECCS Research for Realistic LOCA Analysis, NUREG-1230-R4, U.S. NRC, Washington, DC, USA (1988).
  12. S. Cho, et al.: Core Thermal Hydraulic Behavior during the Reflood Phase of Cold-Leg LBLOCA Experiments using the ATLAS Test Facility, Nuclear Engineering and Technology, 41(10), 1263-1274 (2009). https://doi.org/10.5516/NET.2009.41.10.1263
  13. H. S. Park, et al.: An Integral Effect Test on the LBLOCA Reflood Phenomena for APR1400 Using ATLAS in a Best-Estimate Condition, Journal of Nuclear Science and Technology, 46(11), 1059-1069 (2009). https://doi.org/10.3327/jnst.46.1059
  14. B. J. Yun, et al., "Investigation of the Downcomer Boiling Phenomena during the Reflood Phase of a Postulated Large-Break LOCA in the APR1400," Nuclear Technology 156, pp.56-68 (2006).
  15. H.C. Silva, et al., "Effect of downcomer boiling on LOCA PCT for a 4-loop PWR with a large-dry containment," The 10th Int. Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-10), Seoul, Korea, October 5-9 (2003).
  16. S.W. Lee and S.J. Oh, "Experimental Benchmarking and Safety Analyses of APR1400 Large Break LOCA Scenario," Proc. 5th Int. Congress on Advances in Nuclear Power Plants (ICAPP'05), Seoul, Korea, May 15-19 (2005).
  17. B. J. Yun, et al.: Downcomer Boiling Phenomena during the Reflood Phase of a Large-Break LOCA for the APR1400, Nuclear Engineering and Design, 238, 2064 (2008). https://doi.org/10.1016/j.nucengdes.2007.10.024
  18. H.S. Park, et al., "Recent ATLAS Test Results on the Late Reflood Period of the Large-Break LOCA for APR1400," IAEA Topical Meeting on Advanced Safety Assessment Methods for Nuclear Reactors, Daejeon, Korea, October 30-November 1 (2007).
  19. K.Y. Choi, et al.: Experimental Investigation on Downcomer Boiling with the ATLAS Facility, Proceedings of WORTH-4 (The 4th Korea-China Workshop on Nuclear Reactor Thermal Hydraulics), May 18-20, Jeju, Korea (2009).
  20. K. Stephan and M. Abdelsalam, "Heat Transfer Correlations for Natural Convection Boiling," International Journal of Heat and Mass Transfer 23, pp.73-87 (1980). https://doi.org/10.1016/0017-9310(80)90140-4
  21. B. J. Yun, et al., "Scaling for the ECC bypass phenomena during the LBLOCA reflood phase," Nuclear Engineering and Design 231, pp.315-325 (2004). https://doi.org/10.1016/j.nucengdes.2004.04.005
  22. MPR-1324, "Summary of results from the UPTF downcomer injection/vent valve separate effects tests: Comparison to previous scaled tests, and application to Babcock & Wilcox pressurized water reactors," (1992).
  23. K. H. Kang, et al., Characteristics of Direct ECC Bypass Phenomena on the Accident Simulation of Late-Phase Reflood in the APR1400, Proceedings of the 17th International Conference on Nuclear Engineering (ICONE17), July 12-16, Brussels, Belgium (2009).
  24. H. K. Cho, et al., "Scaling analysis for the Multi-dimensional Phenomena of the ECC Bypass during an LBLOCA with the Direct Vessel Injection," PhD. Thesis, Seoul National University (2004).

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