Comparison of Near-field and Far-field Air Monitoring of Plutonium-contaminated Soils from the Tonopah Test Range, Nevada

Operation Roller Coaster, a series of nuclear material dispersal experiments, resulted in three areas (Clean Slates 1, 2, and 3) of widespread surface soil plutonium (Pu) contamination on the Tonopah Test Range (TTR), located 225 miles northwest of Las Vegas, Nevada. The State's Division of Environmental Protection raised concerns that dispersal of airborne Pu particles from the sites could result in undetected deposition further downwind that the background monitoring stations. Air monitoring data from different distances from the Clean Slate sites but during the same period of time were compared. From the available data, there is no indication that airborne PM10 particles are being transported to the farther distance,however, the data are statistically insufficient to conclude whether there is a difference in transport of respirable Pu particles to the closer verses the farther sites from the Clean Slate sites