Lead attenuation characteristics models

Abstract

Lead attenuation characteristic curves are often consulted in premises radiation shielding assessments employing the non-destructive testing (NDT) method. This study developed lead attenuation characteristics mathematical models for the radionuclide Co-57. These models take into account the statistical variation of the attenuation characteristics. The results are a set of equations that a NDT assessor can use to predict the range of transmission factors for the NDT measurement or, using the inverse functions, to gauge the lead equivalence (with the associated uncertainty) of a radiation barrier. This study showed that the combined effect of types of statistical variations can form an uncertainty region on the transmission characteristics such that the relative uncertainty decreases for values of lead mass per unit area up to approximately 20 kg/m2 and 15 kg/m2 for the Ludlum 18 and Ludlum 2241-2 survey meters respectively but thereafter increases.