After-heat removing device for FBR type reactor

The present invention concerns an after-heat removing device for an FBR type reactor for directly removing after-heat after reactor shutdown by a reactor core cooling system. A lower header is connected to the lower end of a meandering heat-transfer pipe, and a downwarding pipe to be an exit for secondary sodium is connected to the downstream of the lower header. A heat-transfer pipe header is connected to the heat-transfer pipe at a portion where secondary sodium from the lower header to the upstream is forecast for freezing. A bypass pipe is connected between the heat-transfer pipe header and the downwarding pipe, and a stopping valve is connected to the bypassing pipe. A heater is wound around the outer surface of the bypass pipe between the stopping valve and the downwarding pipe. When frozen portion is formed between the heat-transfer pipe header and the lower header, the stopping valve is released, by which the secondary sodium reaches the exit from the heat-transfer header through the bypass pipe. With such a constitution, the amount of the heat removed from the upper header to the heat-transfer pipe header can be ensured. (I.N.)