Development of a PM-10 inlet for continuous operation and with recovery of the >10-μm fraction

The Rocky Flats Plant (RFP) manufactured nuclear weapons' components out of plutonium (Pu) metal until 1990. The plant is now in a decontamination and disposition phase. In both the manufacturing mode and the present mode, Department of Energy (DOE), Environmental Protection Agency (EPA) and the State of Colorado have required continuous monitoring of the air to detect releases of radionuclides. The air surveillance network established around the plant in the early 1950's was replaced in 1972 with a network of high-volume (40 cfm) samplers (hivols). This network extends into the community. The hivois were patterned after the EPA total suspended particle (TSP) samplers with an approximate cutoff at 30 micrometers (μm); however, the RFP version of the TSP sampler was designed to operate continuously and had to be relatively inconspicuous. After nearly 20 years of operation, the RFP air surveillance samplers are in need of updating or replacement, in part because the EPA has now established a new criterion for sampling of suspended particles; i.e., the PM-10 criterion. Only particles of less than 10-μm aerodynamic diameter are considered hazardous to health through inhalation pathways. This report discusses the development of a PM-10 inlet for continuous operation