Component radioactivation is an important problem in accelerator facilities, impacting operations, maintenance, decommissioning, and disposal. Radionuclide inventories are calculated for an 8-cm-diam, 30.9-cm-long lead target irradiated by 660-MeV protons using the particle transport code MCNPX and the transmutation codes CINDER'90, ORIHET-3, and SP-FISPACT. The results using the various codes and data libraries are compared with experimental measurements. Comparisons are also made between the outputs of the three codes for nuclides not represented in the measurements. For more than half the nuclides studied, the codes agree with the measurements within a factor of 2, and nearly all agree within a factor of 10. The present set of codes and nuclear data files are largely adequate for calculating radioactivation in accelerator facilities, but there is room for substantial improvement for selected radionuclides.