Radiological Characterization of Contaminated Pipes of Different Dimensions and Densities

The present work concerns a preliminary  study  for development of a technique  for radiological characterization and segregation of raw historical radioactive waste in different management routes. The efficiency of a 3x3 NaI (Tl) detector for a contaminated cylindrical pipe - detector configuration was evaluated by Monte Carlo simulations performed by using the MCNP code. The efficiency for detector source configuration as well as the measurement bias due to possible inhomogeneity in the distribution of the activity were examined for cylindrical pipes of different densities and dimensions. Cylinders of three different densities made by Pb, Fe, Al were examined. All studied cylinders keep the same ratio between length, diameter and thickness, although the absolute values are different, in order to study the difference in efficiencies of similar geometric objects