PROCESSES OTHER THAN NATURAL TURBULENCE AFFECTING EFFLUENT CONCENTRATIONS [report]

G.A. Briggs, I. Van der Hoven, R.J. Engelmann, J. Halitsky
1968 unpublished
A number of processes other than natural atmospheric turbulent diffusion can be significant in the fate of radioactive material emitted into the atmosphere. First is the effect of momentum and buoyancy due to the mode of emission. Thus, for example, the forced emission of a hot effluent from a stack will cause the plume to rise, depending on both the plume and the ambient-air characteristics. A second process is the surface deposition of airborne material composed of either particulate o r
more » ... articulate o r gaseous matter with resulting depletion of the airborne cloud and quasi-permanent residence of material upon ground surfaces. In the case of radioactivity, surface deposition creates a fixed source of radiation exposure with its cumulative effect as opposed to the rather transitory effect of the airborne cloud. The mechanisms causing deposition a r e numerous and often not well understood. These include gravitational settling (fallout), precipitation scavenging (washout, snowout, and rainout), surface impaction, electrostatic attraction, adsorption, and chemical interaction. A further complica-
doi:10.2172/4500535 fatcat:33nz2yjrifcp7gupe5cecys2ay