Thermalhydraulic Transient Analyses of the SGECS Initial Injection Period

Abstract

Following a secondary side accident event at Darlington NGS, initiation of the SGECS (Steam Generator Emergency Cooling System) will be into steam-filled piping, resulting in a condensation-induced waterhammer transient within the piping network. The TUF (Two Unequal Fluids) computer code, suitable for modelling thermalhydraulic transients with interaction between the liquid and steam phases, was employed to quantify the waterhammer pressure transient within the piping network. enabling piping stress analyses to be performed to verify the structural integrity of the system during the initial injection period. Results of the thermalhydraulic analyses indicate that the piping network undergoes a significant waterhammer transient.