Nuclear material refers to the metals

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...

, and

thorium Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and ha ...

, in any form, according to the

IAEA The International Atomic Energy Agency (IAEA) is an intergovernmental organization that seeks to promote the peaceful use of nuclear energy and to inhibit its use for any military purpose, including nuclear weapons. It was established in 1957 ...

. This is differentiated further into "source material", consisting of natural and depleted uranium, and "special fissionable material", consisting of

enriched uranium Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (23 ...

( U-235),

uranium-233 Uranium-233 ( or U-233) is a fissile isotope of uranium that is bred from thorium-232 as part of the thorium fuel cycle. Uranium-233 was investigated for use in nuclear weapons and as a Nuclear fuel, reactor fuel. It has been used successfully ...

, and

plutonium-239 Plutonium-239 ( or Pu-239) is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three main iso ...

. Uranium ore concentrates are considered to be a "source material", although these are not subject to safeguards under the

Nuclear Non-Proliferation Treaty The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is an international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperatio ...

. According to the Nuclear Regulatory Commission(NRC), there are four different types of regulated nuclear materials: special nuclear material, source material, byproduct material and radium. Special nuclear materials have plutonium, uranium-233 or uranium with U²³³ or U²³⁵ that has a content found more than in nature. Source material is thorium or uranium that has a U²³⁵ content equal to or less than what is in nature. Byproduct material is radioactive material that is not source or special nuclear material. It can be an isotope produced by a nuclear reactor, the tailings and waste that is produced or extracted from uranium or thorium from an ore that processed mainly for its source material content. Byproduct material can also be discrete sources of radium-226 or discrete sources of accelerator-produced isotopes or naturally occurring isotopes that pose a threat greater or equal to a discrete source of radium-226. Radium is also a regulated nuclear material that is found in nature and produced by the radioactive decay of uranium. The half-life of radium is approximately 1,600 years. Different countries may use different terminology: in the

United States of America The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguo ...

, "nuclear material" most commonly refers to " special nuclear materials" (SNM), with the potential to be made into

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear exp ...

s as defined in the Atomic Energy Act of 1954. The "special nuclear materials" are also plutonium-239, uranium-233, and enriched uranium (U-235). Note that the 1980 Convention on the Physical Protection of Nuclear Material definition of nuclear material does not include thorium. The NRC has a regulatory process for nuclear materials with five main components. # Develop regulation and guidance for their applicants and licensees # Licensing, decommissioning and certification for applicants to use nuclear materials, or operate a nuclear facility or decommission a permit license termination # Oversight of licensee operations and facilities that ensure that licensees comply with the safety requirements # Operational experience at licensed facilities or licensed activities # Support for decisions by conducting research, holding hearings that address concerns, and obtain independent reviews that support the NRC regulatory decisions The

United States Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...

Office of Environmental Management (EM) manages and dispositions spent nuclear fuel and surplus nuclear materials. The EM Nuclear Materials Program safely and securely manages the spent nuclear fuels in their facilities while managing an inventory of the materials. The

Nuclear Waste Policy Act The Nuclear Waste Policy Act of 1982 is a United States federal law which established a comprehensive national program for the safe, permanent disposal of highly radioactive wastes. * The US Congress amended the act in 1987 to designate Yucca Mo ...

defines procedures to evaluate and select locations for geological repositories to safely dispose/store the

radioactive waste Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear ...

. The EM also works with the National Nuclear Security Administration (NNSA) to dispose the surplus, non-pit, weapons-usable plutonium-239. EM with the NNSA, oversee the disposition of 21 metric tons of surplus highly enriched uranium materials that has about 13.5 metric tons of spent nuclear fuel.

References

{{Authority control Nuclear weapons

See also

References