VARILLA DE DESPLAZAMIENTO DE REFRIGERANTE PARA REACTOR NUCLEAR DE AGUA BAJO PRESION

摘要

A coolant-displacement rod for a nuclear reactor including a stack of zirconium-oxide pellets in a zirconium alloy cladding. The outer surfaces of certain of the pellets spaced at intervals along the stack include recesses into which the cladding is impressed by the pressurized coolant so as to cause engagement of the cladding encircling each of the pellets with the recessed outer surfaces thereby compartmentalizing the pellets into sub-stacks as the cladding grows permanently axially when exposed to neutron flux. The formation of a long unsupported gap under the cladding which might collapse under the pressure and at the temperature coolant is prevented by forming a plurality of short unsupported gaps instead of one long gap.