10 CFR Part 37—Physical Protection of Category 1 and Category 2 Quantities of Radioactive Material

On March 19, 2013, the NRC published the new 10 CFR Part 37 final rule in the Federal Register (78 FR 16922). The new regulation establishes security requirements for the use and transport of the most risk-significant quantities of radioactive materials (i.e., International Atomic Energy Agency (IAEA) Category 1 and Category 2 quantities of radioactive materials), as well as for shipments of small amounts of irradiated reactor fuel. The Category 1 and Category 2 quantities of radioactive materials are thresholds established by the IAEA in its Code of Conduct on the Safety and Security of Radioactive Sources. The objective of 10 CFR Part 37 is to provide reasonable assurance of preventing the theft or diversion of Category 1 and Category 2 quantities of radioactive materials. The final rule incorporates lessons learned by NRC and the Agreement States in implementing the post-September 11th security measures, as well as stakeholder input on the proposed rule.

The new 10 CFR Part 37 was effective on May 20, 2013, and NRC licensees were to comply with the requirements by March 19, 2014. The NRC confirmed the Agreement States' adoption of adequate and compatible 10 CFR Part 37 requirements by the March 19, 2016, deadline. Upon the effective date of the NRC and Agreement States' requirements, the NRC rescinded the NRC security orders issued under NRC's common defense and security authority (with one exception described below) through formal written correspondence. The NRC as well as the Agreement States also rescinded NRC- or Agreement State-issued orders, removed license conditions, or took any other necessary action with respect to the Increased Controls and Fingerprinting security requirements issued to licensees under the NRC's as well as the Agreement States' public health and safety authority on, or shortly following, the effective dates of their respective requirements.

The order imposing "Trustworthiness and Reliability Requirements for Unescorted Access to Radioactive Materials for Service Providers that are not Manufacturers and Distributors" is the only remaining order that was not rescinded by the NRC upon the effective date of 10 CFR Part 37. This Order was issued to licensees at their request to voluntarily commit to requirements to assess the trustworthiness and reliability of employees to enable them to provide services to licensees with unescorted access. This Order was rescinded on March 27, 2017.

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Types of Licensees Which Part 37 Could Apply To

  1. Industrial Licensees
  2. Academic and Research Licensees
  3. Medical Licensees
  4. Power Reactor Licensees
  5. Research and Test Reactors
  6. Decommissioning reactors
  7. Fuel Cycle licensees

Part 37 Documents

Rule documents

*Update: Effective March 1, 2022, the fee for Criminal History/Fingerprinting transactions is $35.00.  

*Update (September 18, 2020): The mailing address for Fingerprint submissions has changed to:

U.S. Nuclear Regulatory Commission
Director, Division of Physical and Cyber Security Policy
Attn: Criminal History Program/Mail Stop – T-07D04M
11545 Rockville Pike
Rockville, MD 20852

*Reminder: Add "ATTN: Source Management and Protection Branch" in the following address when submitting certifications for reviewing officials:

Director, Office of Nuclear Material Safety and Safeguards,
U.S. Nuclear Regulatory Commission, Washington, DC 20555–0001
ATTN: Source Management and Protection Branch


  • NUREG-2155 – "Implementation Guidance for 10 CFR Part 37, Physical Protection of Category 1 and Category 2 Quantities of Radioactive Material," dated February 2013
  • NUREG-2166 – "Physical Security Best Practices for the Protection of Risk-Significant Radioactive Material," dated May 2014
  • Part 37 rule/Security order comparison (Enclosure 2 to SECY-11-070)

Questions and answers

Other documents


  • Enforcement Guidance Memorandum 2014-001: Interim Guidance for Dispositioning 10 CFR Part 37 Violations with respect to Large Components or Robust Structures Containing Category 1 or Category 2 Quantities of Material at Power Reactor Facilities Licensed Under 10 CFR Parts 50 and 52
  • Enforcement Guidance (Note: NRC will use the current NRC enforcement guidance to disposition Part 37 violations. NRC's current enforcement guidance can be found in the NRC Enforcement Policy, and the NRC Enforcement Manual. Guidance may be revised in the future.)

Contact Us

For any questions or comments related to any 10 CFR Part 37 topic, please send an email to Part37Resource@nrc.gov.

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