Coolant temperature trends in EBR-II reflector subassembliest†

Abstract The radial-reflector subassemblies of the Experimental Breeder Reactor-II (EBR-II) are in the form of large hexagonal-shaped steel blocks inserted into a hexagonal-shaped steel duct with sodium coolant flowing upward in the thin space between the blocks and duct. This geometry combined with the small coolant flow rates and gamma energy deposition rates cause the coolant temperature distributions to be greatly affected by intersubassembly heat transfers. Reported are calculated trends of the coolant temperatures in the six facial intraduct gaps of radial reflector subassemblies surrounding a seven-rowed core and a six-rowed core. Effects of overall changes of reflector region flows and powers are also examined.