Geographical Variations in Environmental Radiation Background in the United States.

Abstract

During the period from March 1 to June 1, 1971, the Lawrence Livermore Laboratory made simultaneous measurements of environmental radiation background at 107 weather stations throughout the United States.Measurements were made using CaF":Dy thermoluminescent dosimeters (TLD-200).Freshly annealed dosimeters were mailed to the stations where they were exposed in the station's instrument shelter. At the end of the exposure period, the dosimeters were returned to Livermore for readout. Light output is proportional to the radiation dose received by the phosphor from the sum of terrestrial and cosmic sources. The cosmic component was estimated from the elevation and geomagnetic latitude of the station, and terrestrial radiation was obtained by difference.Median environmental radiation exposure rate (terrestrial + cosmic) was 9.4 uR/hr with a range from 3.7 to 19.9 pR/hr. The median terrestrial exposure rate was 5.5 pR/hr. Low backgrounds were found in the Hawaiian Islands, Northern Alaska, and Florida. High backgrounds in the Rocky Mountain Work perforated under the auspices of the U. S. Atomic Energy CoiKtission.

An aerial radiological survey of the neutron products company and surrounding area

“…An aerial radiological survey was conducted from November [1][2][3][4][5][6][7][8][9][10]1993, over the Neutron Products Company and neighboring areas. The purpose of the aerial survey was to detect and document any anomalous gamma-emitting radionuclides in the environment which may have been caused by operations at the Neutron Products Company.…”

In situ radiological surveying at the Double Tracks site, Nellis Air Force Range, Tonopah, Nevada

“…This system traveled east and west inside the fenced area within several hundred feet of GZ to look for hot pieces. The collimators on the detectors limited the fields-of-view to about a 0.6-m (2)(3)(4)(5)(6)(7)(8) diameter on the ground. There was sufficient overlap between the fields-of-view to ensure that complete coverage was obtained over an area about 1.5 m (5 ft) wide.…”

An aerial radiological survey of the Davis-Monthan Air Force Base and surrounding area, Tucson, Arizona

“…The detector parameters, A. and R (8), are normally obtained empiricallyfor a given system using standard calibration sources. Mass attenuation coefficients for air and typical soils can be found in standard reference tables.…”