Verification of Advanced Secondary Passive Residual Heat Removal System Based on Full-Scope Simulator

  Introduction  As an important design improvement to cope with the station black out (SBO) accident, the advanced secondary passive residual heat removal (ASP) system is based on the closed natural circulation of secondary side of the steam generator (SG), can effectively remove the residual heat of the reactor core in the case of total loss of feedwater.

  Method  Based on full-scope simulator (FSS),the paper introduced the SBO superimposed SBO diesel engine failure and ASG pneumatic pump failure accident conditions on the simulator platform , and verified the influence of the ASP system for the primary and secondary loops of nuclear plants in accident conditions by using the simulation method.

  Result  The simulation results we obtained demonstrate that after the ASP system was put into operation, the residual heat of the core was effectively removed. After 4 hours , the water level of the SG recover to 8.6 m, the pressure of the SG dropped to 1.2 MPa（a）, the core outlet temperature dropped to about 209 ℃, and the margin of core saturation temperature is greater than 20 ℃, there is no risk of meltdown of the core, and the accident is in a controllable state.

  Conclusion  The ASP system meets the requirements of the design conditions, and can realize the long-term and effective removal of the residual heat of the reactor core.