Research On Simulation Of Load Following Operation In 600MW PWR

With the rapid development of nuclear power industry in China, the proportion of nuclear power generation in the total is increasing in the southeast coastal areas. As a solution,NPPs in these areas need to perform in Load Follow Operation (LFO) during the peak adjustment of power grid.For the research of 600MW NPPs' LFO, this paper takes the Qinshan Phase II NPP Project as the reference. A simulation model is developed by RELAP5/MOD3.4 transient analysis code. After the initialization, the model could simulated the '12-3-6-3' typical daily LFO scheme. By the simulation of different transient process, the dynamic performances of the model are tested. In the calculation of LBLOCA on the '12-3-6-3' typical daily LFO scheme,two transient processes under different initial condition are analyzed. And the change of fuel element cladding temperature over time is calculated.The result of steady state calculation shows that, the performances of the simulation model are consistent with the real PWR operational parameters. After the closed loop connected between the thermal model and control model, the model has the ability to simulate the '12-3-6-3' typical daily LFO scheme,the '5%FP/min linear change of load' and the'10%FP step change of load'. The fuel element cladding temperature in two different initial conditions is lower than 1204?. The result is consistent with the acceptance criteria of the IV class.