Understanding Your NRC or Agreement State License Number: A Quick Reference

If you handle radioactive materials, you've seen the numbers: something like 33-12345-67, or a docket reference like 030-38710. They show up on your license, in correspondence from your regulator, and in compliance reports you receive from consultants like us. Most people who work with these documents every day have never had someone actually explain what the digits mean or why the issuing authority sometimes changes from "NRC" to a state agency and back. Here's a plain-language guide.

Who's actually regulating you: NRC or your state?

The Nuclear Regulatory Commission doesn't directly regulate radioactive materials use in every state. Under Section 274 of the Atomic Energy Act of 1954, the NRC can enter into an agreement with a state's governor that transfers much of its regulatory authority — licensing, inspections, enforcement — to that state. A state that has done this is called an "Agreement State." Kentucky was the first, in 1962; today 40 states hold this status — Connecticut became the most recent, in September 2025 — each running its own radiation control program under standards compatible with the NRC's.

This matters for reading your paperwork because the transfer isn't retroactive in a confusing way, but it does mean the identity of your regulator can change over time. A facility licensed decades ago by the NRC may now be licensed by its state's health or environmental department, because that state became an Agreement State somewhere along the way. When that happens, the state doesn't necessarily start from scratch — it typically continues the existing licensing relationship, though the license may be reissued under the state's own numbering and administrative process. If your file or a report you've received cites both an NRC docket and a state license number, that's usually why: it reflects that transition rather than two separate, unrelated authorizations.

Reading a materials license number

Most NRC and Agreement State byproduct, source, and special nuclear materials licenses (issued under 10 CFR Parts 30, 40, and 70) follow a three-part format:

• The first two digits identify the issuing jurisdiction — a specific state, or the NRC itself when it retains authority.
• The middle five digits identify the specific facility or institution. This segment stays constant across every license held by that same physical location, which is why an organization with several licenses (say, one for a fixed gauge and one for portable devices) will often see the same middle block repeating.
• The final two digits distinguish between multiple licenses issued to that same institution — think of it as a sequence number for "which license is this, out of however many this location holds."

Docket numbers

You'll often see a related but separate number labeled "Docket," formatted like 030-38710. This isn't the license number — it's the tracking number for the regulatory case file itself, and the leading three digits indicate which part of the regulations the material falls under. A single facility can carry more than one docket if it holds licenses spanning more than one of these material categories.

Why the number sometimes doesn't change — and sometimes does

Amendments and renewals generally keep the same license number; the NRC or state simply updates the conditions, authorized uses, or expiration date attached to that existing number. A new license number typically only appears when there's a genuinely new licensee, a new physical location, or a change significant enough that the agency treats it as a new authorization rather than a continuation. If you're comparing an old report to a current one and the number looks different, that's the kind of change worth asking your compliance contact about directly, since the cause is specific to your facility's history.

Reciprocity is its own animal

If you've worked across state lines, you may have run into a "reciprocity" authorization rather than a full license. This lets a licensee from one Agreement State (or the NRC) perform limited, typically time-bound work in another Agreement State without obtaining a full separate license there. It has its own paperwork and its own number series, distinct from your home license, and it's worth not confusing the two when filing records.

The takeaway

Resources

• NRC: Agreement State Program
• NRC: Becoming an Agreement State
• NRC: Backgrounder on Agreement States
• NRC: Agreement State Directory
• NRC Form 313 – Application for Materials License
• 10 CFR Part 30 – Byproduct Material
• 10 CFR Part 40 – Source Material
• 10 CFR Part 70 – Special Nuclear Material
• NUREG-1556, Vol. 9 – Consolidated Guidance