The Department of Energy’s Office of Environmental Management (EM) announced on October 20 that it has achieved a 2020 priority with the removal of another million tons of contaminated soil and debris from the Moab Site in southeastern Utah.
With this latest milestone, EM’s Moab Uranium Mill Tailings Remedial Action project has disposed of a total of 11 million tons of mill tailings from the site along the Colorado River, putting the project two-thirds of the way toward completing the removal and disposal of 16 million tons of mill tailings.
Site employees also recently surpassed a safety milestone, exceeding 1,500 workdays without a lost-time injury or illness, the DOE said.
Quotes: “The ability to adapt to this year’s changing conditions and continue safe operations through these uncertain times is to be commended,” said Moab project manager Greg Church. “Everyone who has contributed to this milestone, and the continued success of this project, can be proud of what they have accomplished.”
History: The Moab Site was home to a uranium ore processing mill constructed in 1956 by Uranium Reduction Company, which later sold the site to Atlas Minerals Corporation. Atlas operated the site under license to the Nuclear Regulatory Commission until 1984, leaving behind an estimated 12 million cubic yards of mill tailings and wastes that formed a pile more than 80 feet thick in an unlined impoundment area on the site.
The DOE assumed ownership of the site in October 2001 and began removing the tailings in April 2009. The project is estimated to be completed in the 2030s.
Engineered disposal: Under the remedial action project, the tailings and debris are being removed from the Moab Site to an engineered disposal cell near Crescent Junction, Utah, about 30 miles away.
To prepare the tailings for removal, workers excavate and condition them in drying beds to reach the optimal moisture content for disposal. The tailings are then placed in steel containers with locking lids for transport.
When the tailings arrive at the Crescent Junction site, they are dumped through end gates in the containers, loaded into dump trucks, and transported to the disposal area where a bulldozer spreads them for compaction. They are compacted in place in layers. After the design thickness has been reached, they are capped with a multilayered cover composed of native soils and rock.