Fabrication, development and application of an annular Al/sub 2/O/sub 3/-B/sub 4/C burnable absorber

A unique advanced design neutron absorber that provides significantly enhanced nuclear characteristics when compared with traditional designs has been developed for use in nuclear reactors. The design is a burnable absorber rod comprised of thin-walled Al/sub 2/O/sub 3/-B/sub 4/C annular pellets contained within two concentric and sealed Zircaloy tubes so as to allow reactor coolant inside the center tube as well as outside the outer tube. A process was devised for fabrication of production quantities of the annular pellets that also satisfies special burnable absorber rod design constraints and performance requirements. This development has resulted in improved utilization of uranium resources and increased fuel management flexibility.