Characterizing dispersion on a climatological basis

Normalized concentrations of pollutants downwind of various nuclear power reactor sites have been predicted with onsite meteorological data and a computer code developed by the U.S. Nuclear Regulatory Commission (Sagendorf and Goll, 1977). These results, grouped by calendar year of meteorological data, were compared and the maximum concentrations were found to vary by a factor of approx. 5 between groups and approx. 3 within groups. Mean values of normalized concentrations of pollutant for each group were found to vary by a factor of approx. 2. Results of this study confirm earlier analysis by Hosler (1964) which indicated that differences in atmospheric dilution among data sites, based on the average effects of wind speed and vertical thermal stability, are small