Outdoor radon monitoring at DOE remedial action sites

The Department of Energy is responsible for the disposal of tailings materials from uranium processing activities formerly performed for the US government. One of the primary radiological hazards of tailings material is the radon gas produced by radium and emitted into the atmosphere. The purpose of the monitoring is to determine to what extent radon concentrations in areas neighboring the processing sites have increased and to measure the success of remedial action in reducing outdoor radon concentrations. Currently, Mound is performing radon monitoring near UMTRA sites at Canonsburg, PA, Salt Lake city, UT, and Shiprock, NM, and near FUSRAP sites at Middlesex, NJ and Lewiston, NY (Niagara Falls Storage Site). Radon monitoring networks of up to 40 monitoring locations are emplaced at the fencelines of these sites and at distances up to 5 km from each site. The monitors are Passive Environmental Radon Monitors (PERMs) and film detectors. With these devices, background radon levels and isopleths of radon concentrations centered on the tailings piles can be determined. This information provides valuable background data for DOE contractor health physics personnel, government officials, and concerned citizens. Prior to remedial action, radon concentrations at the fenceline exceed the DOE guideline limit of 3.0 pCi/liter (yearly average) at some sites; however, radon concentrations are lower than the DOE guidelines at nearly all off-site locations. Generally, radon concentrations drop off to background levels within 2 kilometers of the site. 2 references, 8 figures, 1 table