Types of Nuclear Materials

• Special Nuclear Material consists of plutonium, uranium-233 or uranium with U²³³ or U²³⁵ content greater than that found in nature (i.e., >0.71% U²³⁵)
• Source Material is thorium or uranium with a U²³⁵ content equal to or less than that found in nature (i.e., ≤ 0.71% U²³⁵)
• Byproduct Material, in general, is radioactive material other than source or special nuclear material.  Specifically, by-product material is (a) isotopes produced or created in a nuclear reactor; (b) the tailings and waste produced by extracting or concentrating uranium or thorium from an ore processed primarily for its source material content; (c) discrete sources of radium-226 and (d) discrete sources of naturally occurring or accelerator-produced isotopes that pose a threat equal to or greater than a discrete source of radium-226.
• Radium is a radioactive substance found in nature. Radium is produced by the radioactive decay of uranium. The intensity of radiation from radioactive materials decreases over time. The time required for the intensity to decrease by one-half is referred to as the half-life. The half-life of radium is approximately 1,600 years.

In the United States, there are more than 18,000 source, byproduct, and special nuclear materials licenses. Approximately, 10% of these licenses are administered by the NRC, while the rest are issued by the 40 Agreement States. The National Materials Program is the broad collective framework within which both the NRC and the Agreement States function in carrying out their respective regulatory programs for radioactive material. The NRC regulates special nuclear material when the quantity of the material is enough that a critical mass could form. See Types of Nuclear Materials for more information.

• Medical, Industrial, and Academic Uses of Nuclear Material
• Uranium Recovery Facilities
• Fuel Cycle Facilities
• New Fuels
• Materials Transportation
• Fusion

For general information, see How We Regulate.

The NRC's Office of Nuclear Material Safety and Safeguards (NMSS) (a) regulates activities that provide for the safe and secure production of nuclear fuel used in commercial nuclear reactors; the safe storage, transportation, and disposal of high-level radioactive waste and spent nuclear fuel; and the transportation of radioactive materials regulated under the Atomic Energy Act of 1954; and (b) develops and oversees the regulatory framework for the safe and secure use of nuclear materials; medical, industrial, and academic applications; uranium recovery activities, low-level radioactive waste sites; and the decommissioning of previously operating nuclear facilities and power plants. The agency's four regional offices (Region I – Northeast, Region II – Southeast, Region III – Midwest, and Region IV – West/Southwest) implement the NRC's materials program in the States for which they are responsible.

NRC includes Agreement State representatives in many working groups which enhance the partnership between the NRC and the Agreement States, facilitate the utilization of expertise that exists in the Agreement States, and support the National Materials Program. The working groups can be found at Office of Nuclear Material Safety and Safeguards Working Groups.

The NRC ensures that its materials program complies with the National Environmental Policy Act (NEPA) by conducting NEPA reviews for all major actions within the program. See Materials Environmental Reviews for detailed information on active reviews.