Mathematic Model for Nuclear Power Station with Integrated Secondary-Loop

This paper models the thermal-hydraulic and control systems of nuclear and conventional islands of Ling’ao PhaseⅡ 1000 MW Nuclear Power Station by using RELAP5,and analyzes the turbine load from 100%FP(Rated power) step transient to 90%FP and then from 90%FP step transient to 100%FP.In the simulation of the transient process,the superiority of the integrated secondary-loop model in the analysis of turbine load step transient changes has been indicated.