The Requirement To The Reactor Vessel Auxiliary Cooling System Of Fluoride Salt-cooled High-temperature Reactors Under Three Main Accidents

Thorium Molten Salt Reactor-Solid Fuel 1(TMSR-SF1)from Shanghai Institute of Applied Physics,Chinese Academy of Sciences,is one of the advanced Fluoride SaltCooled High-Temperature Reactor(FHR),with Reactor Vessel Auxiliary Cooling System(RVACS)for decay heat removal.In this paper,based on TMSR-SF1,the cooling process of RVACS under three kinds of incidents such as Station Blackout,Main pump stuck shaft and Loss of heat sink is analyzed.It is concluded that Station Blackout is an envelope for core heat removal decrease accidents.The core power is increased in two ways to obtain high power FHRs.The demand for cooling capacity of the RVACS under the power failure of the whole plant is calculated to obtain the minimum RVACS cooling power required by each power FHR.The results show that RVACS based on air natural convection can be used as FHR passive residual heat removal system with power below 200 MWt and power density below 20 MW / m3.For the higher power FHR using RVACS,two improved methods are proposed,which provide a reference for the design of passive cooling system of the system.