Startup Thermal Analysis of SCWR in Two Different Sliding Pressure Modes

Startup thermal analysis is one of the important aspects of supercritical pressure light water reactor(SCWR) safety analysis. According to the two proposed sliding pressure startup modes, the variation characteristics of different working medium parameters are analyzed in detail. The results show that, the changing of moderator temperature during power increasing process in two modes is different as well as the coolant temperature. But the changing trend of cladding temperature of the two modes is basically the same, while that the maximum cladding temperature in mode 2 is always lower that that in mode 1. There, as mode 1 is chosen, the temperature of both moderator and coolant would increase with only power raised during temperature increasing stage; the coolant temperature is however decreased with both power and coolant flow rate raise in power increasing stage. Then, as mode 2 is chosen, moderator temperature would decrease; the coolant temperature would always rise but with a small change amplitude. It could provide reference for startup design and process control of supercritical pressure light water reactor.