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Backgrounder on Uranium Recovery

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Nuclear reactors use uranium to make electricity, but there are many steps between mining the ore from the ground and turning it into fuel pellets for reactors. "Uranium recovery" is the term for taking uranium ore out of the earth and concentrating (or milling) it into "yellowcake." This powder is converted to uranium hexafluoride, which is enriched to increase the proportion of U-235. Enriched uranium is made into fuel.

The NRC plays a role when uranium ore is processed and physically or chemically altered. This happens at conventional mills, heap leach and in situ recovery (ISR) facilities. The NRC also regulates the storage and disposal of liquid and solid wastes from uranium recovery operations in coordination with other federal agencies and state and Tribal governments. The NRC works with and provides support as needed to states that have taken over the authority to regulate uranium recovery, known as "Agreement States." Uranium mining and exploration are under the control of other federal agencies and the states, not the NRC.

Uranium Recovery Processes

The NRC becomes involved in uranium recovery operations when the ore is processed and physically or chemically altered. This happens either in a conventional, heap leach uranium mill, or ISR. For that reason, the NRC regulates ISR facilities as well as uranium mills and the disposal of liquid and solid wastes from uranium recovery operations (including mill tailings). The NRC does not regulate conventional uranium mining in which the ore is not altered.

Conversion DiagramA conventional mill processes uranium ore that is taken from the ground and crushed. The mill further processes the ore and concentrates the uranium. Mills typically use sulfuric acid to dissolve and remove 90-95 percent of the uranium from the ore. That uranium is separated from the solution, concentrated and dried. Waste from this process can be hazardous to the public and environment due to its radioactive and chemical content. Conventional milling produces a large amount of radioactive sandy residue known as mill tailings. These tailings are confined within an earthen structure. Wells are installed to monitor and detect any contamination of the groundwater.

In heap leach operations, small pieces of ore are piled on a plastic or clay liner. The liner is designed to keep liquids from reaching the soil. An acidic solution is sprayed over the ore to dissolve the uranium. The uranium-rich solution drains into pipes to be transferred to a processing plant, where uranium is concentrated and dried.

An in situ recovery (ISR) plant chemically alters the uranium ore underground before it is pumped out for processing. In the ISR process, wells are drilled into rock with uranium ore. Water, usually mixed with oxygen, hydrogen peroxide and sodium bicarbonate, is injected down the wells to dissolve the uranium in the rock. Operators control the solution underground by pumping out more than is injected. The solution goes to a plant that separates and concentrates the uranium. The In Situ Uranium Recovery ProcessWells must be monitored to ensure that extraction fluids do not leave the facility or contaminate groundwater above acceptable levels. Waste from this process, usually filters and piping, can be disposed in a tailings pile at a mill site or a licensed disposal facility.

Liquid wastes can be disposed in licensed deep wells, evaporation ponds or spray irrigation, or can be treated and discharged to surface water. ISR facilities do not generate tailings. The NRC focuses closely on monitoring and restoring groundwater to protect public health and the environment.


Each new uranium recovery application must meet NRC requirements or those of the Agreement State in which the site is located. The NRC has agreements with six states allowing them to regulate uranium recovery facilities. Washington, Utah, Colorado and Texas are actively overseeing uranium recovery. The NRC regularly evaluates each state through a formal program to ensure they are adequately protecting public health and safety and have programs compatible with the NRC's. The NRC currently regulates active uranium recovery operations in Wyoming, New Mexico and Nebraska.

Locations of NRC-Licensed Uranium Recovery Facility SitesSafety reviews by the NRC or Agreement State focus on an applicant's qualifications, design safety, operating plans and site safety. The NRC also does an environmental review as required by the National Environmental Policy Act. The NRC developed a generic Environmental Impact Statement (EIS) to assess common impacts for sites in the western United States. For each application, the NRC prepares a site-specific supplemental EIS.

The NRC or state issues or amends a license to allow the licensee to construct and operate a new facility or expand or restart an existing one at a specific site. Licensees must meet all regulations and laws as well as specific license conditions. Licenses are for 10 years and can be renewed for additional 10-year periods.

There are several ways to be part of the NRC's decision process. Stakeholders and the public can participate in public meetings, request a hearing, and comment on the EIS and other documents. The NRC notifies the public of these opportunities in the Federal Register or in public meeting notices on the NRC website. The NRC also has a program to work with Native American tribes that may be affected by uranium recovery.

Safety of Operations

The NRC's involvement does not end with an issued license. The NRC inspects facilities regularly to confirm they are complying with requirements. Inspections may occur several times a year at operating facilities or once every two years at facilities in standby mode or being decommissioned.

Locations of NRC-Licensed Uranium Recovery Facility Sites (Table)NRC inspections focus on the areas most important to safety and security, using objective measures of performance. These inspections might look at construction, management organization and controls, radiation protection, chemical processes, radioactive waste management, emergency preparedness, fire safety, and environmental protection. NRC inspectors prepare a report after each inspection. Copies are available to the public through the NRC's documents database. These inspection reports can be located by searching for a licensee's name or docket number.

The NRC evaluates any violations of the requirements to determine their impact on safety. If the safety significance is low, the NRC may discuss the violation with the licensee but not take formal enforcement action. In such a case, the licensee must resolve the problem and prevent recurrence. If the violation has safety significance, the NRC may write a notice of violation. In some cases, the NRC may fine the licensee and issue a press release.


ISR facilities, conventional mills and heap leach facilities must be decommissioned at the end of operations. Licensees are required to remove contaminated structures, decontaminate groundwater and soil, stabilize sites and safely dispose of radioactive waste. ISR licensees must also decommission well fields. That work is complete when the groundwater has been restored to NRC requirements.

These steps must be completed to NRC's satisfaction before the license is terminated. The NRC will only terminate a license for uranium recovery after the site has been cleaned up and stabilized and meets the NRC requirements. Once the license is terminated, the federal government or a state government takes over mill tailings sites for long-term care. The NRC continues to regulate these sites.

NRC's Regulatory Role under UMTRCA

As uranium mining and milling grew in the 1950s and 1960s to support both commercial nuclear power and the military, concerns about health and environmental hazards from mill tailings also grew. In the early days, the Atomic Energy Commission (and later the NRC) regulated mills because they possessed uranium. But it was unclear how the government should regulate mill tailings, which contain both radioactive and chemical wastes. Mill tailings and discarded uranium ore ended up as backfill at numerous sites, including in building foundations, around water and sewer lines and in roadbeds. This use exposed some members of the public to elevated radiation dose rates and radon.

In 1978, Congress passed the Uranium Mill Tailings Radiation Control Act (UMTRCA). Title I created a Department of Energy program to clean up uranium mills that were not licensed and were largely abandoned. After DOE cleans up these sites and contains the mill tailings, it acts as the long-term steward, with the NRC providing oversight. The NRC regulates mills licensed after Nov. 8, 1978, under Title II of the law. In 1983, the Environmental Protection Agency created standards for both "inactive" and "active" tailings sites. The NRC implements and enforces those standards.

While the NRC does not oversee conventional uranium mining, it is cooperating with other federal agencies and the Navajo Nation to address contamination at old mine sites in the Navajo Nation. Progress has been made in reducing risks under the first Five-Year Plan, completed in 2012. Work continues on a second Five-Year Plan. The NRC is also working with EPA and the state of New Mexico to address uranium contamination in the Grants Mineral Belt in and around Grants, N.M.

Current and Future Licensing

There are a number of uranium recovery sites licensed by the NRC. Some are being decommissioned and one is in standby with the potential to restart in the future.

The NRC recently licensed three uranium recovery facilities in Wyoming. During the review, the agency coordinated with the Bureau of Land Management, EPA, the Wyoming Department of Environmental Quality and the Wyoming State Historic Preservation Office. As part of the environmental review under NEPA and to meet the National Historic Preservation Act, the NRC also consulted with state and Tribal agencies that expressed interest in protecting environmental and culture resources near these facilities.

The NRC is reviewing license applications for new facilities or expansions of existing facilities in Wyoming and Nebraska. Based on letters from uranium recovery companies, the agency expects to receive more applications for new facilities, or restarts and expansions of existing facilities, in the next several years. See the current listing of license applications here.

For more information, visit our uranium recovery webpage.

August 2013

Page Last Reviewed/Updated Friday, December 12, 2014