Site evaluation using measured meteorology data

A key factor in reactor site evaluation is the frequency of occurrence of various dispersion conditions and this relationship to potential off-site doses following a reactor accident. Detailed measurements of the wind speed, wind direction, and temperature at heights up to 1200 ft at the Savannah River Plant form the basis for a comprehensive analysis of the frequency of occurrence of potential off-site doses. A complete set of data was taken about every five minutes, and 107,000 sets (about one year of data) were analyzed. The meteorology data were converted to ordinary dispersion parameters through correlating equations developed at Brookhaven National Laboratory. The results were expressed on curves in dose per unit release of activity vs distance from the reactor with probability of occurrence as a parameter. Separate sets of curves were calculated for releases of noble gas and of halogens and at release heights of 200 ft (a nominal stack height) and of 850 ft (about the height of the tallest power plant stacks). Additional curves were developed to show dose as a function of direction and probability of occurrence. In addition to the dose frequency distribution analyses performed as a function of height of release, direction, and distance; more conventional frequency distributions of wind speed, wind direction, and thermal stability were developed as a function of height. All the analyses were carried out on the IBM 360/65. These results represent the first known analysis utilizing data up to 1200 ft and taken often enough to develop reliable frequency distributions for a short term release. (author)