For this study, we have made spectra and integral count rate estimates for a trivial detector configuration with a variety of unclassified gamma-ray sources. The source/background spectra and absolute flux are taken from cumulative distribution files created from MCNP simulations prepared by Ron Wurtz and Mike Frank. The simulated objects were criticality assemblies (test setups to develop benchmarks for establishing safety margins in handling fissile material) taken from the International Handbook of Evaluated Criticality Safety Benchmark Experiments (Nuclear Energy Agency, 2001). These objects were placed inside a 30 cm box with packing material that corresponds to roughly 0.5 radiation lengths (X{sub 0}). The simulations were repeated with an additional 7cm thick steel box enclosure.