Determination of distribution ratios and diffusion coefficients of neptunium, americium, and curium in soil-aquatic environments. Annual report, August 1, 1976--July 31, 1977

The most significant aspect of this research was the finding that distributions of Am, Cm, and presumably Pu cations, between the aqueous and soil phases, are not representative of the real situation. All our experiments indicate that small, easily transported, actinide-bearing particles are responsible for much, if not all of the observed distribution ratio which we call the effective distribution ratio. These actinide-bearing soil particles have radii less than 1000 nm (nanometers). Besides being easily transportable by diffusion and the motion of water itself, these particles are also those that will be most easily resuspended and dispersed in the atmosphere. Thus determination of our effective distribution ratio may lead to an estimate of the fraction of the actinide in a given soil that can be resuspended