Moab UMTRA Uranium Mill Trailings Remedial Action Project
Moab, Utah
The scope of the Moab Uranium Mill Tailings Remedial Action (UMTRA) Project is to relocate mill tailings and other contaminated materials from a former uranium-ore processing facility (millsite) and from off-site properties known as vicinity properties in Moab, Utah, to an engineered disposal cell constructed near Crescent Junction, Utah. The scope also includes active remediation of groundwater at the millsite (Moab site). The U.S. Department of Energy (DOE) Office of Environmental Management in Grand Junction, Colorado, has primary responsibility for managing the Moab Project.
Uranium Reduction Company constructed the Moab mill in 1956 and operated it until 1962 when the assets were sold to Atlas Minerals Corporation (Atlas). Uranium concentrate (known as “yellowcake”), the milling product, was sold to the U.S. Atomic Energy Commission through December 1970 for use in national defense programs. After 1970, production was primarily for commercial sales to nuclear power plants. During its years of operation, the mill processed an average of about 1,400 tons of ore a day.
The milling operations created process-related wastes and tailings, a radioactive, sand-like material. The tailings were pumped to an unlined impoundment in the western portion of the property that accumulated over time, forming a pile more than 80 feet thick. Although more than 90 percent of the uranium was removed during processing, radium and other decay products remained in the tailings, which have an average radioactivity of about 660 picocuries per gram of radium-226. The tailings, especially in the center of the pile, have a high water content. In the past, excess water in the pile drained through underlying soils, contaminating the groundwater. Atlas operated the site until 1984 under a license and regulatory authority provided by the U.S. Nuclear Regulatory Commission (NRC). Atlas demolished the processing buildings and buried them in the southwestern corner of the tailings pile and placed an interim cover over the pile as part of decommissioning activities conducted between 1988 and 1995. There was an estimated 12 million cubic yards (16 million tons) of mill tailings and other contaminated materials present in the pile. Atlas proposed to stabilize the tailings pile at Moab by permanently capping it in place; however, Atlas declared bankruptcy in 1998 and, in doing so, relinquished its license. Because NRC could not legally possess a site it regulated, NRC appointed PricewaterhouseCoopers as the trustee of the Moab Mill Reclamation Trust and licensee for the site. The trustee initiated site reclamation, conducted groundwater studies, and performed site maintenance activities.
In 2008 and 2009, DOE performed extensive infrastructure construction at the Moab and Crescent Junction sites in preparation for moving the mill tailings. In April 2009, DOE began relocating the tailings to the disposal cell. Tailings are excavated and conditioned in drying beds to reach the optimal moisture content for disposal. The tailings are then placed in steel containers with locking lids for transport to Crescent Junction. A gantry crane is used to transfer containers to and from the train at Moab. The Moab Project is currently shipping four trains a week, each carrying up to 156 containers. The Project is currently estimated to be completed in 2029.
At the Crescent Junction site, the containers carrying tailings are unloaded from the train onto trucks that take them to the disposal cell dumping area. The tailings are dumped through end gates in the containers and placed in the cell to meet compaction specifications. The empty containers are reloaded onto railcars and returned to the Moab site.
Moab UMTRA Uranium Mill Trailings Remedial Action Project
Moab, Utah
The scope of the Moab Uranium Mill Tailings Remedial Action (UMTRA) Project is to relocate mill tailings and other contaminated materials from a former uranium-ore processing facility (millsite) and from off-site properties known as vicinity properties in Moab, Utah, to an engineered disposal cell constructed near Crescent Junction, Utah. The scope also includes active remediation of groundwater at the millsite (Moab site). The U.S. Department of Energy (DOE) Office of Environmental Management in Grand Junction, Colorado, has primary responsibility for managing the Moab Project.
Uranium Reduction Company constructed the Moab mill in 1956 and operated it until 1962 when the assets were sold to Atlas Minerals Corporation (Atlas). Uranium concentrate (known as “yellowcake”), the milling product, was sold to the U.S. Atomic Energy Commission through December 1970 for use in national defense programs. After 1970, production was primarily for commercial sales to nuclear power plants. During its years of operation, the mill processed an average of about 1,400 tons of ore a day.
The milling operations created process-related wastes and tailings, a radioactive, sand-like material. The tailings were pumped to an unlined impoundment in the western portion of the property that accumulated over time, forming a pile more than 80 feet thick. Although more than 90 percent of the uranium was removed during processing, radium and other decay products remained in the tailings, which have an average radioactivity of about 660 picocuries per gram of radium-226. The tailings, especially in the center of the pile, have a high water content. In the past, excess water in the pile drained through underlying soils, contaminating the groundwater. Atlas operated the site until 1984 under a license and regulatory authority provided by the U.S. Nuclear Regulatory Commission (NRC). Atlas demolished the processing buildings and buried them in the southwestern corner of the tailings pile and placed an interim cover over the pile as part of decommissioning activities conducted between 1988 and 1995. There was an estimated 12 million cubic yards (16 million tons) of mill tailings and other contaminated materials present in the pile. Atlas proposed to stabilize the tailings pile at Moab by permanently capping it in place; however, Atlas declared bankruptcy in 1998 and, in doing so, relinquished its license. Because NRC could not legally possess a site it regulated, NRC appointed PricewaterhouseCoopers as the trustee of the Moab Mill Reclamation Trust and licensee for the site. The trustee initiated site reclamation, conducted groundwater studies, and performed site maintenance activities.
In 2008 and 2009, DOE performed extensive infrastructure construction at the Moab and Crescent Junction sites in preparation for moving the mill tailings. In April 2009, DOE began relocating the tailings to the disposal cell. Tailings are excavated and conditioned in drying beds to reach the optimal moisture content for disposal. The tailings are then placed in steel containers with locking lids for transport to Crescent Junction. A gantry crane is used to transfer containers to and from the train at Moab. The Moab Project is currently shipping four trains a week, each carrying up to 156 containers. The Project is currently estimated to be completed in 2029.
At the Crescent Junction site, the containers carrying tailings are unloaded from the train onto trucks that take them to the disposal cell dumping area. The tailings are dumped through end gates in the containers and placed in the cell to meet compaction specifications. The empty containers are reloaded onto railcars and returned to the Moab site.