미국
Total Terrestrial Gamma Activity Polygons for an Aerial Radiological Survey of Abandoned Uranium Mines, Navajo Nation, 1994-1999, USEPA and USDOE
This polygon shapefile presents ranges of ground surface exposure rate from total terrestrial gamma activity, and calculated from aerial gross count data (all gamma events in the range of 38-3026 keV). Forty one (41) aerial radiological surveys of potential uranium mining areas (1,144 square miles) were conducted within the Navajo Nation during the period from October 1994 through October 1999. The US Environmental Protection Agency (USEPA) Region 9 funded the surveys and the US Department of Energy (USDOE) Remote Sensing Laboratory (RSL) in Las Vegas, Nevada conducted the aerial surveys. The aerial survey data were used to characterize the overall radioactivity (ground surface exposure rate) and excess Bismuth 214 levels within the surveyed areas.