A method for evaluating a bank of slab-type control rods in enriched hydrogenous reactors considering both thermal and epithermal capture has been developed within the framework of three neutron energy groups. An absorption area technique that combines diffusion theory in the fuel moderator region and a transport condition at the control rod boundary is utilized. The effect of the absorption area is to decrease the source strength for the thermal and epithermal energy groups. The epithermal transmission probability for a non-1/υ absorber is found by an experimental reactivity comparison to a 1/υ absorber. Assuming that the absorption area is uniformly distributed throughout the core, a hand calculation can be made which determines the number, size, and composition of rods necessary to achieve a specific cold shutdown margin.