Mobile Laboratory Tests Soil at UMTRA Site

Gunnison, Colorado--A new mobile laboratory is demonstrating its ability to detect minute traces of contamination at the Gunnison Uranium Mill Tailings Remedial Action (UMTRA) site.

The special laboratory, know as the Mobile Demonstration Laboratory for Environmental Screening Technologies (MDLEST), was developed by scientists at the Department of Energy's (DOE) Ames Laboratory. It can sample and analyze soil and other materials in the field, minimizing the costs, risks and time required for such testing.

This type of on-site testing makes it unnecessary for workers to transport hazardous materials to an off-site laboratory, an advantage that dramatically reduces the costs of testing. The MDLEST technology also minimizes the spread of contamination during the testing process, a frequent problem with older conventional sampling and testing methods.

Earlier this month, technicians drove the MDLEST from central Iowa, where Ames Lab is located, to the Gunnison UMTRA site for a demonstration of its capabilities to detect trace contaminants.

Workers have been removing uranium mill tailings from the Gunnison site since 1992. The mill tailings are sand-like materials left after the extraction of uranium ore, which was mined near Gunnison from 1958 to 1962 for use in national defense. The removed tailings are taken to a permanent storage area 9.6 kilometers southeast of Gunnison.

For the work at Gunnison, soil samples will be brought to the laboratory from areas at the site that have been remediated. Results from MDLEST tests will help UMTRA scientists quickly determine whether enough soil has been removed to sufficiently reduce contamination in these areas.

MDLEST typically gathers samples for analysis through a sampling head that technicians remove from the trailer and position at appropriate areas on the site. A fiber optic cable carries laser light from the trailer to the sampling head, where this light ablates a small soil sample for analysis. Pressurized argon gas lines then carry the ablated sample from the head back to the trailer, where the sample's chemical composition is analyzed.

Lab scientists recently installed a special analytical device in the MDLEST, an inductively coupled plasma-mass spectrometer (ICP- MS) on loan from the Perkin-Elmer Corporation. ICP-MS can detect many of the elements at the part-per-billion level and will allow scientists to conduct a painstakingly precise search for environmental contaminants.

Ames Laboratory, a member of Iowa State University's (ISU) Institute for Physical Research and Technology, is operated by ISU for DOE. The Lab conducts research into various areas of national concern, including energy resources, high-speed computer design, environmental cleanup and restoration, and synthesis of new materials.