Georadiological Barrier Gamma Attenuation Model for Waste Containment. II: Model Implementation

Herein, the Georadiological Barrier Gamma Attenuation Model that is developed in Part 1 of this paper, is utilized to estimate the attenuation of gamma (γ) rays by earthen barriers of various thicknesses and material composition. Activities of radioactive isotopes are calculated and coupled with an exponential absorption equation, to estimate γ exit intensities from these georad barriers. The results indicate that γ attenuation by georad barriers is more significantly affected by barrier thickness than by barrier density. A 33% increase in thickness from 15 to 20 cm produces a 50% reduction in emitted γ intensity, while a 33% increase in density from 1.5 to 2.0 g∕ cm3 produces a 19% reduction for a barrier comprising 45% sand, 25% clay, and 30% water (by weight). This model can be used to optimize barrier material mix composition, density, and thickness to increase γ attenuation in emergency response at existing radiologically contaminated sites and during response scenarios.