Analysis of Water Hammer in the Reactor Coolant System Based on Wave Tracking Method

Abstract To investigate the pressure wave propagation process caused by water hammer in the reactor coolant system, a simulation model of the three-loop main coolant system, consisting of the reactor core, steam generator, main pump, and pressurizer, has been established. The reactor core and steam generator are simplified with equivalent pipes, the pressurizer model is established using a two-phase canister, and the friction torque model of the main pump’s anti-reversal device has been developed. Unlike existing studies, this paper employs the wave tracking method (WTM) for water hammer simulation. Finally, the accuracy of the model is verified by idling experiments after the power failure of the three main pumps (case 1). And the restart of a single main pump after power failure (case 2) and the shaft stuck of the main pump (case 3) are simulated. The results indicate that the simulation results in case 1 are in good agreement with the experimental results, and the pressure wave fluctuates slightly in case 2. In case 3, water hammer occurred in the main pump, the maximum pressure reached 16.66MPa (amplitude 1.47Mpa), and the minimum pressure dropped to 14.97MPa (amplitude −0.94Mpa). The simulation results provide support for the safe operation of the reactor coolant system.