Nuclear Regulatory Commission (NRC)

U.S. federal regulator of byproduct nuclear material — relevant to medical imaging and radiation oncology for PET tracers, Tc-99m generators, I-131 therapy, Y-90 brachytherapy and radioembolization, Ir-192 HDR brachy sources, Co-60 Gamma Knife sources, and theranostic Lu-177 / Ac-225 programs. The NRC's medical-use framework is one of the load-bearing regulatory documents for any program handling unsealed or sealed radioactive material.

What NRC regulates in imaging and therapy

10 CFR Part 35 — medical use of byproduct material. Defines authorized users (Part 35.290 nuclear medicine, 35.300 unsealed therapy, 35.400 sealed-source brachytherapy, 35.500 sealed-source diagnostics, 35.600 Gamma Knife / sealed-source teletherapy), required training, written directives, safety precautions, and incident reporting.
10 CFR Part 20 — occupational and public dose limits, ALARA program, dose-record retention.
10 CFR Part 30 — licensing of byproduct material generally; license types and amendment procedures.
10 CFR Part 71 — packaging and transportation of radioactive material; impacts radiopharmaceutical delivery and waste shipment.
10 CFR Part 19 — notices, instructions, and reports to workers.

Authorized User pathways (Part 35)

35.290 — imaging and localization studies (Tc-99m, F-18 FDG, Ga-67, Tl-201, In-111, etc.).
35.300 — unsealed-source therapy (I-131 thyroid, Lu-177 PSMA / DOTATATE, Y-90 microspheres, Ra-223).
35.400 — manual brachytherapy (LDR seeds, HDR afterloader operations).
35.500 — sealed-source diagnostics (well counters, calibration sources).
35.600 — sealed-source teletherapy / Gamma Knife (Co-60).

Each pathway has its own training, mentorship, and written-directive requirements. AU credentialing is non-transferable by program — staff changes require license amendments.

Agreement States

37 U.S. states have Agreement State status with the NRC — they regulate byproduct material themselves under programs the NRC has determined are compatible. In Agreement States, the state radiation-control program issues licenses rather than the NRC. Federal facilities (VA, DoD, IHS) and non-Agreement-State facilities are licensed directly by the NRC.

Agreement-state regulations sometimes go beyond NRC minimums (more stringent dose limits, additional training requirements, more frequent surveys). Programs operating across state lines navigate two regulators.

Required program elements

Radioactive Materials License — facility-level, with named Authorized Users, listed isotopes, possession limits, and authorized activities.
Radiation Safety Officer — on file, with documented qualifications and authority. Some Agreement States require a deputy RSO and/or a Radiation Safety Committee.
Documented radiation safety program — surveys, dose records, written procedures, ALARA goals.
Dose calibrator + survey meter + area monitoring — equipment with documented calibration and daily / weekly QC.
Waste disposal + regulated transport — decay-in-storage, licensed-broker disposal, manifests, source-return chain of custody.
Incident reporting — misadministration, lost / stolen sources, contamination above thresholds.

Why it matters to buyers

License transferability is NOT automatic in used-equipment purchases. PET / CT, SPECT, Gamma Knife, brachy afterloaders all carry program-level license obligations that travel with the program, not the box.
License amendment timelines — 30 to 120+ days depending on jurisdiction and complexity. Build into install schedule.
Authorized User credentialing — physicians and physicists must be individually named on the license; staff changes are amendment events.
Inspection cycle — typically every 1–5 years depending on license type and inspection history.
Decommissioning has its own license-amendment pathway (final survey, inventory reconciliation, RSO sign-off, closeout inspection in some jurisdictions).

Relevant clinical applications

NRC Licensing (operational guide)
State Radiation Registration (X-ray equipment, separate framework)
AAPM TG-142 (linac QA, distinct framework)
MQSA (mammography, distinct framework)
Radiation Safety Officer
Nuclear Medicine Technologist
Rad Onc Physicist
Nuclear Medicine Decommissioning
PET / CT Decommissioning
Linac Decommissioning