REGLERSTAV FOR EN KERNREAKTOR

摘要

A nuclear reactor control rod containing a stack of B4C absorber pellets in which the pellets in the lower end have a radius smaller than that of the other pellets and are wrapped with a sleeve having a linear compressibility sufficient to accommodate exposure-induced radial expansion of the end pellets without producing excessive clad strain and having a thermal conductivity sufficient to keep the centerline temperature of the end pellets below the melting point of B4C. One such sleeve material is a type 347 stainless steel having 22.5% theoretical density.