An analytical approach to γ-rayγ-ray self-shielding effects for radioactive bodies encountered nuclear decommissioning scenarios

A novel analytical approach is described that accounts for self-shielding of γγ radiation in decommissioning scenarios. The approach is developed with plutonium-239, cobalt-60 and caesium-137 as examples; stainless steel and concrete have been chosen as the media for cobalt-60 and caesium-137, respectively. The analytical methods have been compared MCNPX 2.6.0 simulations. A simple, linear correction factor relates the analytical results and the simulated estimates. This has the potential to greatly simplify the estimation of self-shielding effects in decommissioning activities.

► We describe a novel analytical approach for self-shielding of gamma radiation.
► We examine the correlation between the analytical results with the Monte Carlo simulated results.
► We introduce the simple linear correction factor relates the analytical results with the simulated results.
► We provide the complete mathematical analysis, which can be easily programmed.