A sulfur hexafluoride tracer study at the tracy power plant—I. Preliminary results

A sulfur hexafluoride tracer study at the tracy power plant—I. Preliminary results

A plume tracer and flow visualization experiment has been conducted in the vicinity of the Tracy Power Station near Reno, Nevada during the period 7–20 November 1983. The experiment was undertaken as a preliminary project to help design a larger, full-scale experiment planned for the future. The major objective of the study was to determine the extent of plume impact on the ground, and to ascertain how plume impact is influenced by both terrain and meteorological factors. The tracer experiment involved the release of gaseous SF₆ through the stack of the Tracy Power Station, and the deployment of 53 syringe samplers distributed in an area within 10 km of the release point. Supplementing the tracer measurements were meteorological, remote sensing, and photographic measurements, all designed to visualize the dispersion of the plume. Ten tests were conducted, each lasting a period of up to 9 h. Hourly samples were collected and analyzed for SF₆. Five of the tests resulted in significant plume touchdown within the test area. Although at elevations above the surrounding terrain winds tend to be strong and blow predominantly from the west, SF₆ concentrations were frequently observed both east and west of the power plant. Concentration maxima were localized at discrete locations and altitudes depending on the local meteorological conditions.