Uranium Recovery

Nuclear reactors use uranium to make electricity. But there are many steps between mining the 

ore and turning it into fuel pellets for reactors. “Uranium recovery” is the term for taking the 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, in situ recovery and heap leach facilities. The NRC also regulates the 

storage and disposal of liquid and solid wastes that result, working with other federal agencies and state 

and Tribal governments. The NRC 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

A conventional mill processes ore that is 

taken from the ground and crushed. The mill 

further processes the ore and concentrates the 

uranium. Mills use chemicals 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 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. 

An in situ recovery 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 

h
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by pumping out more than is injected. The solution goes to a plant that separates and concentrates the 

uranium. Wells 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 using 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.

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. No NRC-licensed 

heap leach facilities remain in operation. The 

process has also been used to extract ore at 

conventional mills. 

Licensing

Each new uranium recovery application must meet requirements of the NRC or the Agreement 

State in which the site is located. The NRC has agreements with six states allowing them to regulate 

uranium recovery. Washington, Utah, Wyoming, 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 

regulates active uranium recovery operations in New Mexico, Nebraska and South Dakota. 

Safety 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 to assess common impacts for 

sites in the western United States. For each 

application, the NRC prepares a site-specific 

supplemental EIS. 

A license may allow the licensee to 

construct and operate a new facility or expand or 

restart an existing one. 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.
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There are several ways to be part of the NRC’s decision process. Stakeholders, including the 

general 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 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 regulator’s involvement does not end when it issues a license. The NRC and states inspect 

facilities regularly to confirm they are meeting the requirements. Inspections may occur several times a 

year at operating facilities. For facilities in standby mode or being decommissioned, they would occur 

once every two years.

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.

Decommissioning

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 the 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 
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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. 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.

For more information, visit our uranium recovery webpage.

December 2020