An exact solution to the Gaussian cloud approximation for gamma absorbed dose due to a ground-level release.

Abstract

An exact solution is presented for the classical Gaussian cloud approximation for long-term averaged estimates of gamma absorbed dose due to a ground-level release of radioactive gases and particles. The solution is in the form of relatively simple functions and is much easier to implement than the traditional solution. Also, it is shown that the Gaussian cloud approximation predicts lower absorbed dose than the uniform cloud approximation. The difference is significant when the product of gamma attenuation coefficient and vertical dispersion coefficient is small. Since the Gaussian cloud approximation is based on a more realistic concentration distribution than the uniform cloud approximation, the calculations using the former should give more accurate estimates of the long-term averaged dose for the sector-averaged plume.