Simulation studies of the response function of a radioactive waste assay system

A simulation program based on GEANT 3.21 toolkit was developed to simulate the response function of ISOCART (Ortec) gamma-ray spectrometry system applied to radioactive waste drum assessment. In view of studying the effects of possible non-homogeneous radioactivity distribution in the drum, the volume of the drum was fictitiously divided into several spatial domains. The simulation program was applied repeatedly considering each time the source distributed in another domain. In this way the expected spectra in the energy range from 50 to 2000 keV as well as the full energy peak and the total efficiencies were obtained for the case when the source is distributed in each domain and also for the case when the source is uniformly distributed in the entire drum.

► Calculation technique for calibration of radioactive waste.
► The Monte Carlo simulation program was based on GEANT 3.21 toolkit.
► Response function of ISOCART gamma-ray spectrometry evaluated.
► Volume of the drum fictitiously divided into several spatial domains.
► Full energy peak and total efficiencies evaluated.