TENORM: Uranium Mining Residuals
The mining of uranium ore through underground and surface methods produces varying types and amounts of bulk waste material, including:
- OverburdenSoil and rocks that have been moved out of the way to get to ore are called "overburden." In areas where there are high concentrations of radionuclides in the rock, overburden may have some enhanced radioactivity, but not enough to mine and process.
- Weakly uranium-enriched waste rock.
- Subgrade ores
- Excavated top soil
- Evaporation pond sludges and scales
These materials typically contain radionuclides (and their decay products), including:
The earliest known use of uranium as a pigment dates to the Roman era, and for many years, it was used as a colorant in glasses, glazes, and dyes. The modern uranium mining industry, however, began in the 1940s, primarily to produce uranium for weapons. Most early uranium mines were converted from former vanadium or radium mining and processing sites. Since the 1970s, uranium has primarily been mined for use as nuclear fuel. Uranium mining during this period was conducted by physically removing ore from higher-concentration deposits, by either digging an open pit from the surface or by accessing the deposit through underground tunnels.
With the decreased market price of uranium beginning in the 1980s, U.S. producers turned increasingly to in-situ recovery (ISR) operations to extract uranium from ore. In-situ recovery (also known as “solution mining”) is when fluids are injected into an ore-bearing aquifer to mobilize uranium, which becomes soluble in water. The groundwater containing the dissolved uranium and processing fuel is then extracted through wells, and processed to collect the uranium that was mobilized underground. In-situ recovery is considered by the Nuclear Regulatory Commission (NRC) to be uranium milling, not uranium mining, and the residuals that are produced by this process are regulated as byproduct material. By 2014, according to the Department of Energy's (DOE) Energy Information Administration, there were only approximately six operations in the U.S. to extract uranium from the Earth, and all but one of those were in-situ operations. View the U.S. Energy Information Administration’s Nuclear & Uranium website.
EPA's Uranium Location Database, with information provided by other federal, state, and tribal agencies, includes 15,000 mine locations with known or potential uranium occurrence in 14 western states. View EPA's Uranium Location Database. Most of those locations are found in Colorado, Utah, New Mexico, Arizona, and Wyoming, with about 75 percent of those on federal and tribal lands.
The Atomic Energy Act (AEA) authority does not extend to uranium mining. The uranium fuel cycle as defined by the AEA begins at the uranium mill, after the uranium is removed from its place in nature. Because U.S. laws do not classify mine overburden or waste rock under the AEA as low level radioactive waste or uranium byproduct material, its placement in specialized radioactive waste disposal facilities is not required. Overburden controls generally fall to the states and the tribes responsible for lands in which it is produced.
Neither the NRC, nor the DOE regulate the remediation of conventional (open pit and underground) mining wastes. Restoration regulations are primarily left to the states and the Bureau of Land Management (BLM). However, there are a variety of regulations and guidance designed to protect the public and the environment from exposures to both the hazardous and toxic characteristics of these wastes, which are classified as TENORM.
The DOE’s Defense-Related Uranium Mines (DRUM) program aims to verify and validate the condition of 2,500 defense related uranium mines on federal public land by 2022. Learn more about the DRUM program at DOE.
Under the authority of federal laws, individual states, tribal authorities, or federal land management agencies regulate environmental impacts utilizing clean water and clean air laws. These organizations also have a general authority to protect people and the environment from harmful effects of mining activities.
In contrast, the uranium yellowcakeThe solid form of mixed uranium oxide, which is produced from uranium ore in the milling process. Its color can vary from yellow to orange to dark green. Yellowcake is processed into nuclear fuel. produced from the mined ore is directly regulated because it is source material. Its possession, use, transport, etc. are regulated by either the NRC or its Agreement States. Regulation begins when the uranium is separated from the surrounding rock (beneficiated) or brought into the milling circuit for refining into uranium yellowcake. The regulations also cover production from in-situ leaching operations.
There are no exact totals of these types of materials and residuals in the United States. However, there are estimates based on U.S. Geological Survey (USGS) data. According to USGS estimates, the approximately 4,000 open pit and underground mines in their database (also included in the Uranium Mines and Mills Location Database) generated about three billion metric tons. The volume of waste, including overburden, produced by open-pit mining is approximately 45 times greater than wastes produced from underground mining. Given the larger number of mine locations identified by EPA, the amount of waste rock is likely to be higher.
There are a variety of statutes, regulations and guidance designed to protect the public and the environment from exposures to both the hazardous and toxic characteristics of these wastes, which are classified as TENORM. EPA utilizes the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Clean Water Act (CWA) and the Safe Drinking Water Act (SDWA) to help protect human health and the environment.
An EPA report released in 2008 examines uranium in the United States: its occurrence in natural settings, industrial uses, extraction methods employed over the last century, solid and liquid wastes from various extraction methods and reclamation and remediation methods to restore the extraction site's environment. View this report and other resources on the TENORM technical reports and resources webpage.
View the Uranium Mines and Mills Location Database which contains known or potential mining locations with uranium containing wastes in 14 western states.
EPA’s Ore Mining and Dressing Effluent Guidelines apply to wastewater discharges from ore mines and processing operations. Uranium, radium and vanadium ores are addressed in 40 CFR Part 440, Subpart C.
EPA manages or oversees a number of efforts to address environmental contamination from uranium mining. Under CERCLA, EPA recovered almost $1 billion from a litigation settlement in 2015 to address over 50 mines for which Kerr McGee Corporation and its successor, Tronox, bear responsibility (Press Release). The Navajo Nation received more than $40 million from the settlement. Learn more about the 2015 Tronox Bankruptcy Settlement Agreement.