title: Characterization of surface soils at a former uranium mill.
abstract: Dawn Mining Company operated a uranium mill in Stevens County, Washington, from 1957 to 1982, to process ore from the Midnite Mine, and from 1992 through 2000, to extract uranium from mine water treatment sludge. The mill was permanently shut down in 2001 when the Dawn Mining Company radioactive materials license was amended to allow direct disposal of water treatment sludge to a tailings disposal area at the mill. The mill building was demolished in 2003. Site soil characterization took place in 2004. Soil cleanup is ongoing. Contaminated soils on the site were characterized using a GPS-based gamma scanning system. A correlation between shielded gamma exposure rate and concentration of Ra in surface soils was developed. Subsurface soils were sampled using backhoe trenches. This system proved efficient and accurate in guiding development of the remedial action planning for the site and subsequent soil cleanup.
authors.affiliation: MFG Inc., Fort Collins, Colorado, USA. jan.johnson@mfgenv.com
authors.forename: J A
authors.initials: JA
authors.lastname: Johnson
authors.forename: H R
authors.initials: HR
authors.lastname: Meyer
authors.forename: M
authors.initials: M
authors.lastname: Vidyasagar
mesh_terms: D005720:Gamma Rays; D006801:Humans; D008906:Mining; D012044:Regression Analysis; D012990:Soil Pollutants, Radioactive; D014501:Uranium; D014861:Washington
chemical_list: D012990:Soil Pollutants, Radioactive; D014501:Uranium