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- Author or Editor: Charles L. Simpson x
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Abstract
Values of peak exposure and standard deviations of exposure distributions downwind from a continuous point source are presented for 46 Hanford ground source diffusion experiments. Exposure data are found to order in terms of atmospheric stability when plotted as a function of the travel time. The crosswind variances of the exposure distributions are expressed in terms of the travel time and the product of the standard deviation of the wind direction distribution and the mean wind speed, σθ ū, in an equation resulting from G. I. Taylor's work in 1921.
Prediction methods developed from these concepts permit extrapolation of the results obtained from short releases to much longer release periods. Good agreement between predicted and observed exposure distributions is obtained from these models, using independent data.
Abstract
Values of peak exposure and standard deviations of exposure distributions downwind from a continuous point source are presented for 46 Hanford ground source diffusion experiments. Exposure data are found to order in terms of atmospheric stability when plotted as a function of the travel time. The crosswind variances of the exposure distributions are expressed in terms of the travel time and the product of the standard deviation of the wind direction distribution and the mean wind speed, σθ ū, in an equation resulting from G. I. Taylor's work in 1921.
Prediction methods developed from these concepts permit extrapolation of the results obtained from short releases to much longer release periods. Good agreement between predicted and observed exposure distributions is obtained from these models, using independent data.
Abstract
During the summer of 1959, the Green Glow program, consisting of 26 diffusion experiments during nocturnal inversions, was conducted at the Atomic Energy Commission's Hanford Site near Richland, Wash. The tracer, zinc sulfide, was released near ground level. Samplers were placed at 1.5 m above ground at 533 positions on six sampling arcs, the radii of which were 200 m, 800 m, 1.6 km, 3.2 km, 12.8 km, and 25.6 km. In addition to the ground sampling network, poles or towers were erected at 5 points, 8 deg apart, on each of the 4 inner arcs. Fifteen samplers were mounted on each pole or tower, the top level increasing from 27 m on the 200-m arc to 62 m on the 1.6-km and 3.2-km arcs.
General aspects of the experimental design and tracer technique are discussed along with terrain characteristics and meteorological conditions pertinent to these experiments. Experimental results are presented showing the increase in horizontal plume width and decrease of maximum exposure with distance from the source. An analysis of the area enclosed within a given exposure isopleth is summarized. The effect of significant wind direction shear on the vertical distributions of exposure is discussed. Results from the Green Glow experiments are compared with those from earlier diffusion experiments at O'Neil, Nebr., and later experiments at Hanford.
Abstract
During the summer of 1959, the Green Glow program, consisting of 26 diffusion experiments during nocturnal inversions, was conducted at the Atomic Energy Commission's Hanford Site near Richland, Wash. The tracer, zinc sulfide, was released near ground level. Samplers were placed at 1.5 m above ground at 533 positions on six sampling arcs, the radii of which were 200 m, 800 m, 1.6 km, 3.2 km, 12.8 km, and 25.6 km. In addition to the ground sampling network, poles or towers were erected at 5 points, 8 deg apart, on each of the 4 inner arcs. Fifteen samplers were mounted on each pole or tower, the top level increasing from 27 m on the 200-m arc to 62 m on the 1.6-km and 3.2-km arcs.
General aspects of the experimental design and tracer technique are discussed along with terrain characteristics and meteorological conditions pertinent to these experiments. Experimental results are presented showing the increase in horizontal plume width and decrease of maximum exposure with distance from the source. An analysis of the area enclosed within a given exposure isopleth is summarized. The effect of significant wind direction shear on the vertical distributions of exposure is discussed. Results from the Green Glow experiments are compared with those from earlier diffusion experiments at O'Neil, Nebr., and later experiments at Hanford.
