Optimization Research on the Operating Diagram of HPR1000 Units

Aiming at the narrow area of the operating diagram of HPR1000 nuclear power unit under specific conditions, this paper makes an optimization analysis and research on the operating diagram from the aspects of increasing the operating pressure of the residual heat removal (RHR) system, lowering the lower limit of the start-up pressure of reactor coolant pump, enlarging the allowable temperature difference between the two ends of the pressurizer surge line, and lowering the limit of the sub-cooling of the reactor coolant. And then, an optimized operating diagram for HPR1000 is proposed. The comparative analysis before and after optimization shows that the optimized operating diagram has a wider allowable operation range, improved operation efficiency and enhanced operation reliability.