Individuals or organizations desiring to possess and use portable nuclear gauges must obtain a license issued by the applicable regulatory agency. In the U.S., the Nuclear Regulatory Commission (NRC) has jurisdiction over the licensing and regulation of radioactive material. However, under agreement with the NRC, thirty-three states (so-called Agreement States) have assumed responsibility for issuing licensing and enforcing radiation protection regulations within their borders. The NRC requires Agreement State regulations to be compatible with (although not necessarily identical to) NRC regulations. Detailed guidance on preparing NRC or Agreement State license applications is contained in the Troxler Licensing Guide. For information regarding sealed source and device (SS&D) registration sheets, click here.


License Amendment

Licensees must request amendments to their licenses whenever the information originally submitted is no longer valid or they wish to make a change that affects the license. In general, license amendments must be submitted and approved before making the requested change, e.g., changing the location of the licensed activities or acquiring licensed materials not listed on the license. The licensing agency should be notified of any changes in personnel listed on the license as soon as possible.

License Renewal

Radioactive materials licenses have expiration dates and must be periodically renewed. If a licensee submits a renewal application at least 30 days before the expiration date, the license is automatically extended until the regulatory agency acts upon the application. If this is done, the license is referred to as being “under timely renewal.”


In general, Agreement States will recognize and honor a valid license issued by another state or the NRC. The NRC in turn recognizes licenses issued by Agreement States. This is referred to as reciprocal recognition or reciprocity. Typically, a state will allow an out-of-state licensee to conduct licensed activities for between 30 and 365 days, but most typically 180 days, in a calendar year under reciprocity. To conduct activities for more days than permitted under reciprocity, a specific license must be obtained in that state. All states require at least a 3-day advance notice, a copy of a valid license, and submission of information about the nature, location, and dates of the proposed activities before authorizing licensed activities under reciprocity. Most states also require payment of a reciprocity fee. See the Agreement State table for a listing of fees and links to state web sites where more information can be obtained. Click here for reciprocity information by state.