Reflood process is an important part of LOCA,and it is crucial to identify the transient thermal characteristics of core during reflood process for the safety analysis of break accident.Based on the subchannel analysis code CTF,the transient analysis and calculation are carried out for the reflood process of Xi'an pulsed reactor in typical large and small break loss of coolant accidents.In the analysis,the core is divided into eight channels based on power.The spatiotemporal distribution characteristics of the quenching front and core temperature are obtained,and the temperature changes of the cladding and fuel rod center at different heights of fuel rods at different positions are analyzed.The results show that the temperature of the outer fuel rods is lower and completely cooled earlier than that of the hottest rod at the center.Under both large and small break conditions,the coolant can completely submerge the core,allowing it to cool completely.Under large break conditions,due to higher decay power,it takes longer for the core to be completely cooled.The risk of cladding failure is relatively low under large break conditions,while the risk of cladding failure in small break accidents is higher compared to large break conditions.Fuel pellet melting will not occur under both large and small break conditions.
Pulsed reactorRefloodCore temperatureSubchannel codeSafety features
维普
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