Radioactive Waste From Uranium Mining and Milling

Radiation Facts

Regardless of how uranium is removed from rock, the extraction process creates radioactive wastes. If not managed properly, mining waste and mill tailings can contaminate the environment.

Uranium is a naturally-occurring radioactive element that has been mined and used for its chemical properties for more than a thousand years. It is now primarily used as fuel for nuclear reactors that make electricity. Uranium can be recovered in two ways: by conventional mining of the rock (ore), or by using strong chemicals to dissolve uranium from the rock that is still in the ground and pumping it to the surface.

On this page:

About Radioactive Waste From Uranium Mining and Milling
What you can do
Where to learn more

About Radioactive Waste From Uranium Mining and Milling

Image of Davis Uranium Mine — Mine wastes outside the Davis Uranium Mine in Colorado.

Industries in the United States recover uranium from the Earth through mining or chemical extraction.

Mining: When uranium is near the surface, miners dig the rock out of open pits. Open pit mining strips away the topsoil and rock that lie above the uranium ore. When uranium is found deep underground, miners must dig underground mines to reach it. The rock is then removed through underground tunnels.
In situ leaching: “In situ” is Latin for “in place.” In situ leaching ISL), or in situ recovery (ISR), is the process of pumping chemicals into groundwater to dissolve uranium in porous rocks (typically sandstones. When uranium is located in an area saturated by groundwater, at relatively greater depths and generally lower concentrations than for conventional mines, in situ leaching may be used. After the chemicals are put into the ground, the liquid containing uranium is pumped to the surface through a network of wells and then processed to recover the uranium. This has become the most commonly used uranium extraction method in the United States in recent decades, especially in Texas and Wyoming.

Once the uranium ore is extracted from the Earth, it must be processed to get the uranium from the ore. There are a few processes that can be used to recover uranium:

Milling: This process takes place at a mill after the ore containing uranium is removed from the Earth through open pit or underground mining. The ore is brought to a mill, crushed, and ground up before chemicals are added to dissolve the uranium. The uranium is then separated from the chemical solution, solidified, dried and packaged.
Heap leaching: This process uses a liquid to dissolve metals found in rocks (ores). Similar to the way pouring hot water over crushed coffee beans leaves coffee grounds (waste) and liquid coffee, spraying chemicals over piles of uranium-containing crushed rock leaves the leftover rock and a liquid containing uranium. The liquid then needs further processing to recover the uranium. This processing method is not currently used in the United States for uranium, but it is used for gold.

Regardless of how uranium is extracted from rock, the processes leave behind radioactive waste. These processes separate uranium from its decay products which are also radioactive and actually contain most (80-90%) of the radioactivity in the rock (ore). The solid radioactive wastes that are left over from the milling processes are called tailings and the liquid wastes are called raffinates. Mill tailings and raffinates are stored in specially designed ponds called impoundments. The tailings remain radioactive and contain hazardous chemicals from the recovery process.

mine area warning sign in John Brown Canyon, CO — Image of a warning sign on forest access road near a uranium mining area in Mesa County, Colorado.

Uranium eventually decays to . Radium decays to release a radioactive gas called radon. Open pit uranium milling and in situ mining sites do not pose a significant radon risk to the public or to miners; the radon disperses into the atmosphere. In the past, the waste rock produced by underground and open pit mining was piled up outside the mine. This practice has caused problems, including on Navajo lands where more than half of the small, abandoned uranium mines from the middle of the 20^th century and their wastes remain. Wind can blow radioactive dust from the wastes into populated areas and the wastes can contaminate surface water used for drinking. Some sites also have considerable groundwater contamination.

Underground mines can present a radiation hazard to miners. Without proper air ventilation, can collect in the mineshafts, where it is inhaled by miners. The operators of uranium mines must take special precautions to protect miners, such as pumping radon gas out of the mine and replacing it with fresh air. To protect the public near uranium mines, vented radon gas must not exceed certain limits. Sometimes miners are required to wear respirators that protect their lungs from radon gas. Learn more about the health effects of radon at Radon in Homes, Schools and Buildings.

Previously, waste rock and mill tailings were used in some Western mining areas as building materials for homes, schools, roads and other construction. Structures built with waste rock and mill tailings were radon and radiation hazards to anyone spending time in them. People traveling on roads made with waste rock were in danger of breathing radioactive dust. In response to these issues, the 1978 Uranium Mill Tailings Radiation Control Act (UMTRCA) stopped the use of mill tailings in building and construction projects.

What You Can Do

Avoid both abandoned and operating mining sites and equipment. This will limit your exposure to potential radioactive wastes stored on-site.
Obey safety instructions. Follow all posted warnings and safety guidance near operating or abandoned mining sites. You should never:
- Swim in or drink the water from open pit mine lakes.
- Drink the water from streams and springs near either abandoned or operating uranium mines.
- Remove rock or soil from a uranium mine.

Where to Learn More

The U.S. Environmental Protection Agency (EPA)

The EPA relies on several regulations and laws to protect people and the environment from radiation exposure from the uranium extraction process. The Uranium Mill Tailings Radiation Control Act (UMTRCA) sets limits on radium in soil from mill tailings, in response to which EPA issued Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings. The Clean Air Act limits the amount of radon that can be released from tailings impoundments and underground uranium mines. Runoff water from mines, mills, and ore piles is regulated under the Clean Water Act. The Safe Drinking Water Act sets limits for radionuclides in drinking water. Some uranium mining and milling sites are cleaned up under the EPA Superfund program.

The Plain English Guide to the Clean Air Act
This webpage describes the EPA's Clean Air Act in plain English.

Summary of the Clean Water Act
This webpage provides a summary of the Clean Water Act and provides links to information about the statute.

Safe Drinking Water Act (SDWA)
This webpage provides links to information and fact sheets about the Safe Drinking Water Act.

Subpart B: National Emission Standards for Radon Emissions from Underground Uranium Mines
Subpart B of the National Emissions Standards for Hazardous Air Pollutants (NESHAPs) protects people and the environment from radon emissions from underground uranium mines.

Technologically Enhanced Naturally-occurring Radioactive Materials (TENORM)
This webpage provides information about TENORM including health effects, industry information, and links to information about managing TENORM.

Uranium
This webpage provides general information about uranium, including sources of uranium, uranium in the environment and health information.

The U.S. Nuclear Regulatory Commission (NRC)

The NRC licenses and oversees the operations of mills, heaps and in situ leaching mines. The NRC rules for tailings impoundments are based on EPA limits. Facilities must prove they have a radiation safety program to protect workers in order to get an NRC license.

Uranium Recovery Regulations, Guidance, and Communications
This webpage provides information about the NRC’s regulations and guidance for uranium recovery.

Directory of Agreement State and Non-Agreement State Directors and State Liaison Officers
This webpage provides a list of the U.S. Nuclear Regulatory Commission Agreement and Non-Agreement State contacts.

The States

Each state has a radiation program that ensures the safe use of radioactive materials. Many states have signed formal agreements with the NRC to get authority over the licensing and operations at mills and in situ leaching mines. These states are known as Agreement States. Agreement States inspect facilities to make sure the staff is properly trained and that equipment is operating safely.

State Radiation Protection Programs
The Conference of Radiation Control Program Directors (CRCPD)
This webpage provides links and contact information for each state's Radiation Control Program office.

The U.S. Department of Labor (DOL), Mine Safety and Health Administration (MSHA)

MSHA enforces safety and health rules at mines and mills. These rules help reduce health hazards and prevent accidents in the nation's mines and mills.

Mine Safety and Health Administration
This webpage contains information about worker safety in United States’ mines.

The U.S. Department of Energy (DOE)

The DOE takes control of closed and reclaimed mills. At the direction of Congress, the DOE cleans up mill sites and vicinity properties.

Defense-related Uranium Mines Program
This webpage provides information about the DOE’s Report to Congress and the Defense-related Uranium Mines Program Management Plan.

The U.S. Department of the Interior (DOI), the Bureau of Land Management (BLM)

The BLM manages 262 million acres of land—about one-eighth of the land in the United States. The Bureau manages about 700 million more acres of underground mines, including uranium mines. The Office of Surface Mining provides funds to many state and tribal agencies for cleaning up uranium mines on their land.

Abandoned Mine Lands
This webpage describes BLM activities related to abandoned mine lands and curates information across the federal government related to mining.

The U.S. Army Corps of Engineers (USACE)

The USACE operates the Formerly Utilized Site Remedial Action Program (FUSRAP). Its job is to identify and clean up old, contaminated facilities that supported the federal government in the early years of the nation's atomic energy program. Some of these sites have radioactivity levels above today's regulatory limits. Through FUSRAP, federal agencies, state and local governments and property owners work together to keep radioactive material on these sites under control. The Corps of Engineers also assist the EPA and tribes in cleaning up abandoned mines on Native American lands.

Formerly Utilized Sites Remedial Action Program
This webpage provides information and frequently asked questions and answers about the Army Corps of Engineer's FUSRAP.