Application of the Absorption Area Method To Three-Group Diffusion Theory Problems

The absorption area method allows rod absorptions to be considered without treating the rods as discrete boundaries. The source neutrons for a rod absorbing neutron energy group are reduced in proportion to the rod absorption area. This paper presents rod absorption factors based on absorption area calculations that may be applied in any reactor region penetrated by the rods. The factors derived are dependent on the core and rod composition, rod geometry, and include rod interaction effects.