Use of Global Positioning Systems for Accelerated Independent Verification of Cleanup at a Superfund Site
P. V. Egidi, M. K. Jensen, A. R. Jones, M. J. Wilson-Nichols, S. M. Smith, G. A. Pierce, J .L. Zutman
The Monticello Mill Tailings Site Remedial Action Project (Operable Unit 1) underwent remediation from 1997 to 1999 under the Comprehensive Environmental Response, Compensation, and Liability Act. Peripheral properties (those adjacent to or affected by the millsite) also were remediated during the same time frame as Operable Unit II. The U.S. DOE designated Oak Ridge National Laboratory, Environmental Technology Section, located in Grand Junction, Colorado as the independent verification (IV) contractor for the mill site and peripheral properties. Uranium mill tailing, ore, and other process-related materials were remediated from the 31.6 hectare (ha) site, and from the 121.5 ha peripheral properties. Cleanup criteria were established for Ra-226, Th-230 and total uranium for surface and subsurface deposits. Complicating the verification process was the adoption of supplemental standards for some peripheral properties, and different survey protocols for the millsite and the peripherals, such that a variety of cleanup standards and methodologies for various nuclides were applicable. Cleanup at this site was conducted on an expedited schedule, with limited time for field verification activities, requiring innovative approaches were needed to meet the schedule. Gamma radiation scans were conducted using differential global positioning system (GPS) technology to collect spatial and radiological data. Results were then used to validate the effectiveness of the cleanup by sorting the data for areas that exceeded the mode by 30%, and contouring and plotting the data. Areas exceeding the mode were then checked for residual activity. Maps and tables were prepared from the data collected using the GPS facilitating the report writing process. Experience gained from this project has resulted in a cost-effective methodology for monitoring and documenting cleanups at these and other sites.
This abstract was presented at the 33rd Annual Midyear Meeting, "Instrumentation, Measurements, and Electronic Dosimetry", Site Characterization Session, 1/30/2000 - 2/2/2000, held in Virginia Beach, VA.