General License Uses of Nuclear Materials

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See also Frequently Asked Questions About General Licenses.


NRC's regulations provide a general license for the use of byproduct material contained in certain products. This general license allows certain persons to receive and use a device containing byproduct material if the device has been manufactured and distributed in accordance with a specific license issued by the NRC or by an Agreement State.

A specific license authorizing the distribution of generally licensed devices is issued if a regulatory authority determines that the safety features of the device and the instructions for safe operation of the device are adequate and meet regulatory requirements. The general licensee must comply with the requirements for labeling, instructions for use, and proper storage or disposition of the device.

A generally licensed device usually consists of radioactive material contained in a sealed source within a shielded device, such as gas chromatograph units, fixed gauging devices, static eliminators, luminous exit signs, calibration or reference standards, some ice detection devices and in vitro laboratory kits. The device is designed with inherent radiation safety features so that it can be used by persons with no radiation training or experience. Consequently, the general license simplifies the licensing process so that a case-by-case determination of the adequacy of the radiation training or experience of each user is not necessary. NRC evaluates the adequacy of these generally licensed products, ensuring that distributors meet the specific requirements in 10 CFR Part 32 Subpart B and that users meet the requirements in 10 CFR Part 31.

General distribution licenses only authorize the distribution of products and devices to general licensees and do not authorize the possession or use of radioactive material. Therefore, applicants for general distribution licenses must file a separate application for a specific license authorizing possession and use of byproduct material. Applicants file with the NRC Regional Office or Agreement State for the State where the material will be possessed or used.

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Types of Generally Licensed Devices (10 CFR Part 31)

A general license is issued to persons or organizations who acquire, receive, possess, use or transfer the following types of devices.

Certain Detecting, Measuring, Gauging, or Controlling Devices and Certain Devices for Producing Light or an Ionized Atmosphere (10 CFR 31.5)

The use of byproduct material contained in devices designed and manufactured to detect, measure, gauge, or control thickness, density, level, interface location, radiation, leakage, or qualitative or quantitative chemical composition, or ionizing air, or for producing light (e.g., gas chromatograph units; moisture/density, fill level, insertion and transmission gauges; static eliminators, self-luminous exit signs, and ion generating tubes).

The regulations in 10 CFR 31.5 require certain general licensees who possess devices containing at least 370 MBq (10 mCi) of cesium-137, 3.7 MBq (0.1 mCi) of strontium-90, 37 MBq (1 mCi) of cobalt-60, 3.7 MBq (0.1 mCi) of radium-226, or 37 MBq (1 mCi) of americium-241 or any other transuranic (i.e., element with atomic number greater than uranium (92)) to register with the NRC.

General License to Install Devices Generally Licensed (10 CFR 31.6)

Any person who holds a specific license issued by an Agreement State authorizing the holder to manufacture, install, or service a device, as described in 10 CFR 31.5, within such Agreement State is granted a general license to install and service such devices in any non-Agreement State and in offshore waters.

Luminous Safety Devices for Use in Aircraft (10 CFR 31.7)

Regulations allow the use of byproduct material, specifically tritium or promethium-147, contained in luminous safety devices, such as luminous exit signs and dials, for use in aircraft, except that promethium-147 is not generally licensed in instrument dials. The devices may contain no more than 10 curies of tritium or 300 millicuries of Pm-147.

Americium-241 and Radium-226 in the Form of Calibration or Reference Sources (10 CFR 31.8)

The use of americium-241 and radium-226 is authorized in calibration or reference sources by any person in a non-Agreement State or any government agency that holds a specific license authorizing the receipt, possession, use, and transfer of byproduct material, source material, or special nuclear material. The general licensee must not possess more than 5.0 microcuries at any one time in a location of use or storage of such sources.

General License for Strontium-90 in Ice Detection Devices (10 CFR 31.10)

The use of strontium-90 contained in ice detection devices on board aircraft is generally licensed provided that the devices contain no more than 50 microcuries.

General License for Use of Byproduct Material for Certain In Vitro Clinical or Laboratory Testing (10 CFR 31.11)

A general license is issued to physicians, clinical laboratories, hospitals, and veterinarians in the practice of veterinary medicine authorizing the possession and use of byproduct material in prepackaged units (e.g., kits, sources, and standards) for in vitro clinical or laboratory tests not involving internal or external administration of byproduct material or the radiation therefrom to human beings or animals. For possession limits go to 10 CFR 31.11.

Possession of byproduct material under 10 CFR 31.11 is not authorized until the physician, clinical laboratory, hospital, or veterinarian in the practice of veterinary medicine, has filed NRC Form 483 and received from the Commission a validated copy of NRC Form 483 with a registration number.

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General license for certain items and self-luminous products containing Radium-226 (10 CFR 31.12)

A general license is issued to any person to use radium-226 contained in certain products manufactured prior to November 30, 2007, such as:

  • Antiquities originally intended for use by the general public.
  • Intact timepieces containing greater than 0.037 MBq (1 microcurie), nonintact timepieces, and timepiece hands and dials no longer installed in timepieces.
  • Luminous items installed in air, marine, or land vehicles.
  • All other luminous products, provided that no more than 100 items are used or stored at the same location at any one time.
  • Small sources containing no more than 0.037 MBq (0.1 microcurie) of radium-226.

Page Last Reviewed/Updated Tuesday, January 11, 2022