Flow and pressure-induced transient analysis of the supercritical-pressure, light-water-cooled and moderated reactor

The supercritical-pressure, light-water-cooled and moderated reactor (SCLWR) is the thermal neutron spectrum reactor using uranium dioxide, stainless steel clad fuel and double-tube water rods for moderation. The flow and pressure-induced events should be analyzed for assessing the technical feasibility of the SCLWR, since the coolant system is the once-through type as a supercritical-pressure, fossil-fired power plants. The basic safety requirement is to maintain the flow rate. The pressure and the flow rate are detected for the safety signal. A computer code was developed to simulate the SCLWR behavior at the supercritical-pressure. The total loss of feedwater flow and feedwater pump shaft seizure are analyzed as the accidents. The loss of feedwater heater, inadvertent start of the auxiliary feedwater system, partial loss of feedwater flow, loss of off-site power and generator load rejection are analyzed as the transients. The maximum stainless steel cladding surface temperature was used as criterion for the accident. The minimum deterioration heat flux ratio, the ratio of the critical heat flux to the maximum one, should be above unity at the transients for avoiding the deterioration of heat transfer. All analyzed transients and accidents satisfied criteria. The SCLWR tolerates the flow and pressure-induced accidents and transients, although there are only two coolant loops