Analysis of the Influence of G Rods Calibration Curve Deviation on RRC Load Change Transients

The reactor control system (RRC) load linear change test is to verify the capacity of PWR reactor control system to maintain the main parameters in normal operation range under the condition of linear change in unit load. In reactor power control system, the G rods calibration curve reflects the relationship between the nuclear power of the reactor and the electric power of the steam turbine, which is controlled by the rod position indicating and rod control system (RGL). For the reactor power control system is an open-loop control system, the accuracy of G rods calibration curve directly affects the response capacity of each control system under linear load variation. When there is a significant deviation in the calibration of G rods calibration curve, it may cause a rapid load reduction of steam turbine after triggering C signal in the process of load linear change test, resulting in the failure of transient. This paper analyzes the transient results of load change under different G rods calibration curve deviations through system program simulation, and provides suggestions on the allowable range of relevant deviations, providing important technical basis for safe operation of the unit.