| Abstract |
During 1975, the monitoring of gamma radiation levels in the environs of the NTS was continued through the use of an off-site network of radiation dosimeters and gamma-rate recorders. Concentrations of radionuclides in pertinent environmental media were also continuously or periodically monitored by established air, milk, and water sampling networks. Before each underground nuclear detonation, mobile radiation monitors, equipped with radiation monitoring instruments and sampling equipment, were on standby in off-NTS locations to respond to any accidental release of airborne radioactivity. An airplane was airborne near the test area at detonation time to undertake tracking and sampling of any release which might occur. A total of about 22 curies (Ci) of radioactivity, primarily radioxenon, was reported by ERDA/NV as being released intermittently throughout the year. The only off-NTS indications of this radioactivity from test operations were low concentrations of xenon-133, krypton-85, and tritium (hydrogen-3) in various combinations, measured in air samples collected at Beatty, Diablo, Hiko, Indian Springs, and Las Vegas, Nevada. The concentrations at these locations when averaged over the year were less than 0.01 percent of the Concentration Guide of 1 x 10 exp -7 microcuries per millilitre ( mu Ci/ml) as listed in the ERDA Manual, Chapter 0524, for exposure to a suitable sample of the population. Based upon time-integrated concentrations of the nuclides at these locations, dose calculations, and population information, the whole-body gamma dose commitment to persons within 80 km of the NTS Control Point for test operations during this year was estimated to be 0.00065 man-rem. The highest dose commitment, *0.062 man-rem occurred beyond 80 km of NTS at Las Vegas, Nevada, a location with a much higher population density than any within 80 km of NTS. (ERA citation 02:001492) |
