Optimal Design of Entrance Characterization Signal of Diversified Drive System

KDS (Diversified Drive System), as the backup of the RPS (Reactor Protection System), should deal with the RPS software CCF (Common Cause Failure) superimposed on the DBC (Design Basis Condition) while alleviating the consequences of the ATWT (Anticipated Transient Without Trip). Through in-depth analysis of KDS accident operation guidelines and RPS failure causes, it is found that the existing KDS entrance characterization will not be generated when only RPS failure and no DBC occurs, and the operator cannot be informed of the failure of the RPS at the first time. Based on the function principle and application scenario of BEEP function block, this paper determines the fault diagnosis method of RPS equipment, and proposes an optimized design of KDS entrance characterization signal. The results show that the design can cope with the failure of individual RPS, allowing operators to intervene with the unit earlier, without waiting for DBC to occur before taking action.