Optimization Scheme for Bypass Valve in Unit 1 of Yang Jiang Nuclear Power Plant

After the replacement of FISHER by MASONEILAN to regulate the feedwater valve in Unit 1 of Yang Jiang Nuclear Power Plant, the parameters of the feed water bypass control system does not match the actual situation, and it directly results in the steam generator water level fluctuations, and thus brings the reactor trip. The control logic ARE407/408/409RG（small valve control function curve） curve function in ARE system is optimized, and the steam load and the discharge of water is matched by optimizing the control function to compensate for the inconsistent of field devices and control logic. Comparison of optimized and reference units showed that for the steam generator level disturbance at the switchover point for the small and large valves during the normal power rising and during the valve switchover test for 30%FP platform, the test result in Unit1 of Yang Jiang Nuclear Power Plant is significantly better than that for the reference unit.