An In Situ Radiological Survey of Three Canyons at the Los Alamos National Laboratory

An in situ radiological survey of Mortandad, Ten Site, and DP Canyons at the Los Alamos National Laboratory was conducted during August 19-30, 1996. The purpose of this survey was to measure the quantities of radionuclides that remain in the canyons from past laboratory operations. A total of 65 in situ measurements were conducted using high-resolution gamma radiation detectors at 1 meter above the ground. The measurements were obtained in the streambeds of the canyons beginning near the water-release points at the laboratories and extending to the ends of the canyons. Three man-made gamma-emitting radionuclides were detected in the canyons: americium-241 (241Am), cesium-137 (137Cs), and cobalt-60 (60Co). Estimated contamination levels ranged from 13.3-290.4 picocuries per gram (pCi/g)for 241Am, 4.4-327.8 pCi/g for 137Cs, and 0.4-2.6 pCi/g for 60Co