Development of vertical dispersion coefficients for rolling terrain environments. [Mathematical models]

Technical Report · Sat Jan 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/7300369· OSTI ID:7300369

Sherer, D. L.; Minott, D. H.; Hilst, G. R.

The Gaussian plume dispersion model is used to calculate expected concentrations of radioactive material downwind from point or line sources, including planned nuclear power stations. The standard Pasquill-Gifford dispersion coefficients (sigma/sub ..gamma../, sigma/sub Z/) normally used with the Gaussian model have been developed primarily for flat, smooth terrain. For terrains that are not flat and smooth, other dispersion coefficients which account for the dispersive effects of terrain-induced mechanical turbulence are needed. It is ERDA's objective to specify reliable dispersion coefficients that will represent a broader range of topographic conditions than was intended for the standard Pasquill-Gifford coefficients. The U. S. Army has carried out a program with similar objectives, but most of the information generated has had little visibility beyond the Department of Defense. During the first phase of this ERDA project, release of the Army data was arranged, and in this second phase of work, data from Army tracer-dispersion tests have been used to develop coefficients for dispersion over rural, rolling terrain. In order to derive vertical dispersion coefficients characteristic of rural, rolling terrain from the Army data, the meandering plume hypothesis has been applied. The meandering plume hypothesis holds that total dispersion (sigma/sub ZT/) is comprised of two components; the first component, sigma/sub ZI/, is the diffusion of a plume segment (puff) about its own center; the other component (sigma/sub ZM/) is the meander of individual puff trajectories about the centerline of the time-averaged plume.

• Research Organization: Research Corp. of New England, Wethersfield, CT (USA)
• OSTI ID: 7300369
• Report Number(s): COO-4026-5
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220500 -- Nuclear Reactor Technology-- Environmental Aspects
500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
DIMENSIONS
ENVIRONMENTAL EFFECTS
ENVIRONMENTAL TRANSPORT
GEOMETRY
HEIGHT
MASS TRANSFER
MATHEMATICAL MODELS
MATHEMATICS
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
PLUMES
POWER PLANTS
RADIOACTIVE EFFLUENTS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
THERMAL POWER PLANTS
TOPOGRAPHY
TURBULENCE
VELOCITY
WASTES
WIND