Cleanup of windblown tailings contamination at the Grants Uranium Mill

The cleanup of windblown tailings contaminated soils covering a 500 hectare (1200-acre) area was efficiently accomplished through a combination of innovative radiological survey technique and associated cleanup verification method. The approach was to couple gamma radiation detectors to global positioning systems to obtain high density gamma count rate data. A correlation between gamma count rate and Ra-226 in soil was determined and a gamma-count-rate action level established, at the 95 percent confidence level, that corresponded to the Ra-226 concentration limit. A verification plan was approved by the U. S. Nuclear Regulatory Commission that incorporates the use of the high density gamma-ray data as a primary verification method with a very limited confirmatory soil sampling program. Approximately 1.5 million cubic meters of contaminated soil was removed and consolidated with the mill tailings. Employment of this technology allowed this work to be accomplished quickly with significant cost savings compared to conventional radiological survey methods.