Analysis of Reflux Cooling in the SG U-Tubes Under Loss of RHRS During Midloop Operation with Primary System Partly Open

  • 발행 : 1998.04.01

초록

The present study is to assess the applicability of the best-estimate thermal-hydraulic codes, RELAP5/MOD3.2 and CATHARE2V1.3U, to the analysis of thermal-hydraulic behavior in PWRs during midloop operation following the loss of RHRS. The codes simulate an integral test, BETHSY 6.94, which was conducted in the large scale test facility of BETHSY in France. The test represents the accident where the loss of RHRS occurs during midloop operation with the pressurizer and upper head vents open and the sight level indicator broken. Besides, the hot legs are half filled with water and the upper parts of the primary cooling system are filled with nitrogen, with a letdown line open and only one SG available. The purposes of this study are to understand the physical phenomena associated with reflux cooling in the 5G U-tubes when noncondensable gas is present under low pressure and to assess the applicability of the codes to simulate the loss of RHRS event by comparing the predictions with the test results. The results of the study may contribute to actual applications for plant safety evaluation and description of the emergency operating procedure.

키워드

참고문헌

  1. NUREG-1449 Shutdown and Low-Power Operation at Commercial Nuclear Power Plants in the United States USNRC
  2. NUREG/CR-6144 Evaluation of Potential Severe Accidents During Low Power and Shutdown Operations at Surry, Unit 1 T.L.Chu(et al.)
  3. International Topical Meeting on Safety of Thermal Reactors Loss of Residual Heat Removal (RHR) During PWR Mid-Loop Operation: Experiments in ROSA-IV/LSTF H.Nakamura;Y.Anoda;Y.Kukita
  4. Proceedings of the NURETH-4 Loss of Residual Heat Removal During Midloop Operaion: BETHSY Experiments D.Dumont(et al.)
  5. Nuclear Technology v.108 RELAP5/MOD3 Simulation of the Loss of the Residual Heat Removal System During a Midloop Operation Experiment Conducted at the ROSA-IV Large Scale Test Facility Y.A.Hassan;S.S.Benerjee
  6. Nuclear Technology v.93 Palo Verde Nuclear Generating Station Midloop Condition RETRAN Model K.R.Parrish;H.A.Till
  7. NUREG/CR-5855 Thermal-Hydraulic Processes During Reduced Inventory Operation with Loss of Residual Heat Removal S.A.Naff(et al.)
  8. Nuclear Technology v.103 Simulation of Loss of RHR During Midloop Operations and the Role of Steam Generators in Decay Heat Removal Using the RELAP5/MOD3 Code Y.A.Hassan;L.L.Raja
  9. SETh/LES/87-38 BETHSY Data Base P.Bazin
  10. CEN Note STR/LES/93-140 BETHSY Test 6.9d : Loss of Residual Heat Removal System During Midloop Operation (Primary System Partly Open) - Test Report B.Noel
  11. NUREG/CR-5535 RELAP5/MOD3.2 Code Manual INEL
  12. CENG/SETh/LES/90-07 BETHSY General Description Barre;Bernard
  13. International Journal of Heat and Mass Transfer v.22 A General Correlation for Heat Transfer during Film Condensation inside Pipes M.M.Shah
  14. NP-2192 Critical Flow Data Review and Analysis D.Abdollahian(et al.)
  15. CNSI Specialist Meeting on Transient Two Phase Flow Condensation Modeling for ECC Injection J.Janicot;D.Bestion