Aerial radiological survey of the Argonne National Laboratory and surrounding area, Argonne, Illinois

摘要

An aerial radiological survey was conducted during the period May 17 through May 26, 1989, over a 32-square-mile (83-square-kilometer) area surrounding the Argonne National Laboratory (ANL) facilities located near Argonne, Illinois. The survey was conducted at a nominal altitude of 150 feet (46 meters) with line spacings of 200 feet (61 meters). A contour map of the terrestrial gamma exposure rate extrapolated to 1 meter above ground level was prepared and overlaid on an aerial photograph and a set of United States Geological Survey topographic maps of the area. The terrestrial exposure rates varied from 7 to 15 microroentgens per hour ((mu)R/h). The highest observed level over the ANL facility buildings was in the contour range of 247 to 512 (mu)R/h. A search of the data for man-made sources of radiation indicated the presence of cobalt-60 and/or cesium-137 over most of the buildings with elevated count rates. Manganese-54 was detected over one of the sites where cobalt-60 was also seen. A comparison of the contour plots from the present survey and the previous surveys was made. How- ever, due to changes in instrumentation since the last survey, a direct comparison is not possible. Soil samples and pressurized ion chamber measurements were obtained at five locations within the survey boundaries to support the aerial data. These data were found to agree with the aerial data.