Aerial radiological survey of the Portsmouth Gaseous Diffusion Plant and surrounding area, Portsmouth, Ohio. Date of survey: July 1990

摘要

An aerial radiological survey was conducted from July 11--20, 1990, over an 83-square-kilometer (32-square-mile) area surrounding the Portsmouth Gaseous Diffusion Plant located near Portsmouth, Ohio. The survey was conducted at a nominal altitude of 91 meters (300 feet) with line spacings of 122 meters (400 feet). A contour map of the terrestrial gamma exposure rate extrapolated to 1 meter above ground level (AGL) was prepared and overlaid on an aerial photograph and a set of United States Geological Survey (USGS) topographic maps of the area. The terrestrial exposure rates varied from about 7 to 14 microroentgens per hour ((mu)R/h) at 1 meter above the ground. Analysis of the data for man-made sources and for the uranium decay product, protactinium-234m ((sup 234m)Pa), showed five sites within the boundaries of the Portsmouth Gaseous Diffusion Plant with elevated readings. Spectra obtained in the vicinity of the buildings at the Portsmouth Gaseous Diffusion Plant showed the presence of (sup 234m)Pa, a uranium-238 ((sup 238)U) decay product. In addition, spectral analysis of the data obtained over the processing plant facility showed gamma activity indicative of uranium-235 ((sup 234)U). No other man-made gamma ray emitting radioactive material was detected, either on or off the Portsmouth Gaseous Diffusion Plant property. Soil samples and pressurized ion chamber measurements were obtained at five different locations within the survey boundlaries to support the aerial data.