Reaction rates of 115In(n, n′) and 90Zr(n,2n) were measured on various axial positions inside single slabs of 18-cm-thick beryllium and 15-cm-thick lead kept in front of a Haefely deuterium-tritium neutron generator. These experimental axial activity profiles, and those for the zirconium/indium ratio, are compared to those computed using the two-dimensional discrete ordinates code DOT 3.5 coupled to a compatible first-collision source evaluator code GREATUNCL. Generally, a satisfactory agreement is seen between these profiles for both beryllium and lead slabs.