Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Containment Closure Time Following the Loss of Shutdown Cooling Event of YGN Units 3&4

  • Published : 1999.02.01
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Abstract

The YGN Units 3&4 plant conditions during shutdown operation were reviewed to identify the possible event scenarios following the loss of shutdown cooling (SDC) event. For the five cases of typical reactor coolant system (RCS) configurations under the worst event sequence, such as unavailable secondary cooling and no RCS inventory makeup, the thermal hydraulic analyses were performed using the RELAP5/MOD3.2 code to investigate the plant behavior following the event. The thermal hydraulic analyses include the estimation of time to boil, time to core uncovery, and time to core heat up to determine the containment closure time to prevent the uncontrolled release of fission products to atmosphere. The result indicates that the containment closure is recommended to be achieved within 42 minutes after the loss of SDC for the steam generator (SG) inlet plenum manway open case or the large cold leg open case under the worst event sequence. The containment closure time is significantly dependent on the elevation and size of the opening and the SG secondary water level condition. It is also found that the containment closure needs to be initiated before the boiling time to ensure the survivability of the workers in the containment. These results will provide useful information to operators to cope with the loss of SDC event.

Keywords

References

  1. NUREG-1449 Shutdown and Low Power Operation at Commercial Nuclear Power in the United States USNRC
  2. NUREG/CR-6144 v.2 Evaluation of Potential Severe Accidents During Low Power and Shutdown Operations at Surry Unit 1-Analysis of Core Damage Frequency From Internal Events During Mid-Loop Operations T.L. Chu(et al.)
  3. NUREG-1269 Loss of Residual Heat Removal System-Diablo Canyon, Unit 2 USNRC
  4. NUREG-1410 Loss of Vital AC Power and the Residual Heat Removal System During Mid-loop Operations at Vogtle Unit 1 on March 20, 1990 USNRC
  5. GL 88-17 Loss of Decay Heat Removal USNRC
  6. KINS/GR-060 Safety Evaluation on Shutdown Operation of Nuclear Power Plants H.J. Kim(et al.)
  7. the 26th WRSM Proceedings Low-Power and Shutdown Models for the Accident Sequence Precursor(ASP) Program M.A. Sattison(et al.)
  8. NUREG/CR-5535, USNRC, (INEL-95/0174) v.1-5 RELAP5/MOD3 Code Manual: User's Guide and Input Requirements K. E. Larson(et al.)
  9. NUREG/IA-0143 Assessment of RELAP5/MOD3.2 with the LSTF Experiment Simulating a Loss of Residual Heat Removal During Mid-Loop Operation K.W. Seul(et al.)
  10. Nuclear Technology Plant Behavior Following o Loss of Residual Heat Removal Event under Shutdown Condition K.W. Seul(et al.)
  11. International Conference on New Trends in Nuclear System Thermodynamics PWR Thermal-hydraulic Phenomena Following Loss of Residual Heat Removal During Mid-loop Operation H. Nakamura;Y. Kukita
  12. International Conference on New Trends in Nuclear System Thermodynamics RELAP5/MOD3 Simulation of the RHR System during Midloop Operation Experiment Conducted at the ROSA-IV Large Scale Test Facility S. Banerjee;Y. A. Hassan
  13. Abnormal-45, Rev. 2, PNSC no.96-49 Operating Procedure of YGN Units 3&4: Actions Following Loss of SDC System KEPCO
  14. Revision 4, SA-13-C00-95-005 Safety Analysis Operational Data APS
  15. Nuclear Technology v.93 Palo Verde Nuclear Generating Station Midloop Condition RETRAN Model K.R. Parrish;H.A. Till