Generally Licensed Devices Under 10 CFR Part 31

A general license lets a facility possess certain radioactive devices — a bone densitometer source, a fixed gauge, a static eliminator, a check source — without filing a specific license application, but it is not a free pass: 10 CFR Part 31 still requires leak testing, annual registration above activity thresholds, transfer only to authorized recipients, and prompt reporting of loss or damage. Forgotten generally licensed devices are one of the most common sources of orphan sources and NRC enforcement, which is exactly why they deserve a deliberate place in a hospital's radiation safety program.¹²

Most radiation safety officers (RSOs) know their specific license cold — the authorized users, the possession limits, the survey records. Far fewer can immediately list every generally licensed device in the building, even though those devices carry their own legal duties and their own failure modes. This article explains what a general license is and is not, which devices fall under 10 CFR Part 31, the specific obligations the holder cannot delegate away, a worked example of why a decaying source still has to be managed, and how to build generally licensed devices into a defensible program. DRPS supports facilities through radioactive material license support and radiation safety officer consulting across Florida, Maryland, Virginia, Washington DC, California, Nevada, Pennsylvania, New York, New Jersey, and Delaware.

Introduction

The U.S. system for regulating radioactive material uses two kinds of license: a specific license, issued to a named applicant after the regulator reviews its program, and a general license, granted automatically by regulation to anyone who meets the stated conditions. A general license removes the application step for low-risk, factory-sealed devices, but it does not remove the user's responsibilities — it simply packages them into the rule itself.¹³

For a medical facility, generally licensed devices tend to accumulate quietly: a bone densitometer with a sealed gadolinium-153 source, a static eliminator on a film processor or packaging line, a check source for a survey meter, or an analytical instrument source. Because none of these arrived with a license application, they are easy to overlook — and that is precisely the accountability gap the NRC's 2000 registration rulemaking set out to close.² This guide covers the legal framework, the device types, the holder's duties, the worked physics of source management, and the regulatory and program context.

Topic Explanation

Specific versus general license

A specific license is issued to a particular person or institution after the regulator evaluates the proposed use, facilities, equipment, and radiation safety program; a general license is conferred by regulation on any person who acquires a qualifying device and agrees to abide by the conditions in the rule.¹³ The manufacturer of a generally licensed device holds a specific license (under 10 CFR Parts 30 and 32) to evaluate, register, and distribute the device; the end user then possesses it under the general license in 10 CFR Part 31.¹³⁴

Key terms used throughout this guide:

• General license — authority granted by rule (10 CFR Part 31), not by an issued document, to possess and use a specified device under stated conditions.
• Sealed source and device (SSD) registration — the safety evaluation a manufacturer completes so a device may be distributed; the device's registration certificate defines its use and testing conditions.
• Removable contamination — radioactive material that can be wiped from a sealed source, measured by a leak (wipe) test.
• Orphan source — a source that has been abandoned, lost, or otherwise removed from regulatory control.

Which devices are generally licensed

The central provision for device holders is 10 CFR 31.5, covering "certain detecting, measuring, gauging, or controlling devices," plus devices for producing light or an ionized atmosphere.¹ Typical examples a hospital or clinic may encounter include:

• Bone densitometer sources — older dual-energy x-ray absorptiometry (DEXA) and single-/dual-photon units used sealed gadolinium-153 or iodine-125 sources distributed under general license.
• Fixed gauges — level, density, or thickness gauges using cesium-137, cobalt-60, or americium-241.
• Static eliminators — polonium-210, nickel-63, or americium-241 devices on processors or packaging equipment.
• Self-luminous products — tritium exit signs (covered under the related provisions of Part 31) and similar devices.
• Analytical and instrument sources — electron-capture detector (nickel-63) sources and some calibration/check sources.

The common thread is a factory-sealed source in a device whose safe use does not require the end user's own radiation safety evaluation — provided the conditions of the general license are met.¹

Key Technical Principles

The conditions that ride with a general license

10 CFR 31.5(c) attaches binding conditions to every qualifying device. The holder must:¹

• Follow the label and registration certificate. Install, use, service, and test the device only as specified; do not remove labels.
• Leak-test the source for leakage and proper operation at the interval specified on the label or registration certificate, keeping records.
• Suspend use on failure. If a test detects 185 Bq (0.005 µCi) or more of removable radioactive material — or there is any sign of shielding or on/off-mechanism failure — immediately take the device out of service and file a written report with the NRC within 30 days.
• Transfer only to authorized recipients. The device and its material may be disposed of or transferred only to a person holding the appropriate specific license (manufacturer, licensed service company, or authorized waste broker), or as otherwise approved by the regulator — never abandoned or discarded.
• Report loss or theft and maintain records of transfers.
• Register annually above threshold (see below).
• Not export, and not transfer to the general public, outside the rule's terms.

These are not optional best practices; they are the terms of the license, and failing them is a regulatory violation that can draw enforcement even though no application was ever filed.¹²

The annual registration threshold

Under 10 CFR 31.5(c)(13), a general licensee must register — annually, using NRC Form 664, and pay the fee in 10 CFR 170.31 — any device containing at least:¹⁵⁷

• 370 MBq (10 mCi) of cesium-137, or
• 3.7 MBq (0.1 mCi) of strontium-90, or
• the specified quantities of cobalt-60 and transuranic radionuclides listed in the rule.¹

Registration requires the holder to verify, correct, or add to the device information the regulator requests (location, responsible individual, serial number, and status), and each location of use is treated as a separate general licensee requiring its own registration and fee.¹ Devices below these thresholds — including many gadolinium-153 densitometer sources — are still generally licensed and still carry the leak-test, transfer, and reporting duties, but are not on the annual-registration list.¹

Worked example: a decaying densitometer source still needs managing

Gadolinium-153 has a physical half-life of about 240.4 days,⁸ so a sealed DEXA source decays quickly. Suppose a densitometer was installed with an initial activity $A_0=1.48\text{GBq}$ (40 mCi). The decay constant is:

After two years ($t=730$ days) the remaining activity is:

The source has fallen to about one-eighth of its original activity, which is why pencil-beam DEXA sources are replaced on a schedule to maintain image quality and scan speed. The radiation safety point is the key one: decay does not end the general license. At 4.9 mCi the source still requires leak testing, still may only be transferred to an authorized recipient, and still must be accounted for — a decayed source that is quietly discarded becomes an orphan source and a violation.¹² The same arithmetic tells the RSO when a replacement is due and when the old source must be sent back to a specific licensee.

Comparison: specific license versus general license

The table makes the practical distinction clear: the general license trades the application process for a fixed set of rule-based duties — it does not eliminate the duties.¹³

Clinical Impact

For a hospital, the real risk from generally licensed devices is not acute dose — it is lost accountability. Because these devices are acquired without an application and often run for years unattended, they slip out of institutional memory. An old densitometer is decommissioned and the source is forgotten; a static eliminator is scrapped with the equipment it was attached to; a check source leaves with a retiring technologist. Each of these is how an orphan source is created, and each can trigger an NRC or Agreement State enforcement action against the facility that held the general license.¹²⁶

The accountability problem was significant enough that the NRC issued a final rule in December 2000 specifically to require registration of the higher-activity generally licensed devices and to strengthen the transfer and reporting provisions, precisely because tracking had been poor.² For a medical physicist or RSO, that history is the lesson: generally licensed devices must be inventoried and managed as deliberately as specifically licensed material, even though the paperwork burden looks lighter. For the related obligations on sealed sources that the facility does hold under a specific license, see our guides to sealed source leak testing and sealed source inventory and accountability.

Practical Optimization Tips

Build a generally licensed device inventory

• Find every device. Walk the facility — densitometry, imaging, laboratories, loading docks, packaging lines — and list every sealed-source device, including those not on the specific license. Capture radionuclide, activity, serial number, registration certificate, and location.¹
• Assign accountability. Name a responsible individual for each device and record it; the general license obligations follow the facility, so someone must own them.
• Flag the registration-threshold devices. Identify any device meeting the 31.5(c)(13) thresholds and confirm the annual Form 664 registration and fee are current.¹⁵

Keep the duties current

• Schedule leak tests at the label/registration-certificate interval and keep the records; a missed leak test is a common, avoidable citation.¹
• Know the 0.005 µCi rule. If a leak test meets or exceeds 185 Bq (0.005 µCi) removable, take the device out of service, report within 30 days, and arrange repair by a specific licensee or disposal by authorized transfer.¹
• Plan end-of-life now. Record the manufacturer or service company that can accept each source, and budget for return/disposal before the device is retired — never let a source leave control by scrap or trash.¹²

Coordinate with licensing and transfers

Because a generally licensed device moves between parties only through specific licensees, and because Agreement States run their own equivalent programs, transfers across state lines and device decommissioning should be coordinated with the facility's broader licensing work. This connects to radioactive material license support and the end-of-life planning discussed in decommissioning and license termination.

Regulatory Considerations

Generally licensed devices are governed primarily by 10 CFR Part 31, which sits within the broader byproduct-material framework of Parts 30 and 32 and the fee schedule in Part 170.

• 10 CFR Part 31 — General Domestic Licenses for Byproduct Material. Establishes the general license and, in 31.5, the conditions, leak-test, registration, transfer, and reporting duties for detecting, measuring, gauging, and controlling devices.¹
• 10 CFR Part 30 — Rules of General Applicability. The umbrella licensing rules for byproduct material, including transfer and reporting principles.³
• 10 CFR Part 32 — Specific Domestic Licenses to Manufacture or Transfer. The specific-license basis under which manufacturers evaluate (SSD registration) and distribute generally licensed devices.⁴
• 10 CFR 170.31 — Schedule of Fees. Sets the registration and licensing fees, including the general-license device registration fee.⁵
• NRC Form 664 — General Licensee Registration. The form used to satisfy the 31.5(c)(13) annual registration.⁷

Agreement States administer their own equivalent general-license programs. Of the jurisdictions DRPS serves, Florida, Maryland, Virginia, California, Nevada, Pennsylvania, New York, and New Jersey are NRC Agreement States that regulate these devices under their own radiation-control rules, while Washington, DC and Delaware are regulated directly by the NRC. A device that is generally licensed in one jurisdiction remains subject to the receiving authority's rules when it moves, so confirm the requirements with the authority having jurisdiction before transferring or relocating a device. For the jurisdictional framework, see NRC, Agreement States, and FDA jurisdiction, and for the manufacturer-side evaluation, see sealed source and device registration.

Frequently Asked Questions (FAQs)

What is a generally licensed device?

A generally licensed device contains byproduct material in a sealed source and is distributed to end users under a general license granted by regulation, without the user filing a specific license application. Examples include bone densitometer sources, fixed gauges, static eliminators, self-luminous exit signs, and some instrument sources. The general license is in 10 CFR Part 31; the device is evaluated and registered by its manufacturer under a specific license.¹⁴

Is a general license the same as having no license?

No. It is a real license with real duties. Under 10 CFR 31.5 the holder must follow the label and registration certificate, leak-test the source, keep the device in working order, transfer it only to authorized recipients, report loss or damage, and — above threshold — register annually and pay a fee.¹

Which generally licensed devices require annual registration?

Under 10 CFR 31.5(c)(13), devices containing at least 370 MBq (10 mCi) of cesium-137, 3.7 MBq (0.1 mCi) of strontium-90, or the specified quantities of cobalt-60 and transuranics must be registered annually using NRC Form 664 with a fee under 10 CFR 170.31. Devices below those thresholds are still generally licensed but not on the registration list.¹⁵

What is the leak-test requirement for a generally licensed device?

The source is tested for leakage and proper operation at the interval on the label or registration certificate. If a test detects 185 Bq (0.005 µCi) or more of removable radioactive material, the device must be removed from service immediately, reported to the NRC within 30 days, and repaired only by a specific licensee or disposed of by authorized transfer.¹

Can a hospital throw away or sell a generally licensed device?

No. The device and its radioactive material may only be transferred to a person holding the appropriate specific license — typically the manufacturer, a licensed service company, or an authorized waste broker — or as otherwise approved by the regulator. Abandoning it, discarding it in trash, or selling to an unauthorized party is a violation.¹

Why do generally licensed devices cause compliance problems?

Because they are acquired without an application and run for years unattended, they are easy to forget. Old densitometer sources, static eliminators, and check sources are a leading source of orphan and lost sources and a frequent enforcement subject. Inventory every device, assign accountability, and fold leak testing, registration, and end-of-life transfer into the radiation safety program.¹²

Key Takeaways

• A general license is granted by rule (10 CFR Part 31), not by application, but it carries binding duties — it is not "no license."¹³
• Common medical-facility examples include DEXA sources, fixed gauges, static eliminators, exit signs, and check sources.¹
• Holders must leak-test the source and act on the 0.005 µCi (185 Bq) removable-contamination threshold with a 30-day report.¹
• Devices above 10 mCi Cs-137, 0.1 mCi Sr-90, or the listed cobalt-60/transuranic quantities require annual Form 664 registration and a fee.¹⁵
• Devices may be transferred or disposed of only to specific licensees — never abandoned, trashed, or sold to an unauthorized party.¹
• Forgotten devices become orphan sources; a deliberate inventory with assigned accountability is the defense.²

Conclusion

The phrase "general license" is deceptively reassuring. It removes the application, but it leaves intact a full set of obligations — labeling, leak testing, registration above threshold, authorized-only transfer, and loss reporting — all written directly into 10 CFR Part 31. For a medical facility, the danger is not that a bone densitometer source or a static eliminator will deliver a large dose; it is that an unregistered, forgotten device will leave regulatory control and surface as an orphan source during an inspection or a renovation. The remedy is unglamorous and effective: inventory every generally licensed device, assign a responsible individual, keep the leak tests and registrations current, and plan each source's authorized end-of-life before it is needed. Treated this way, generally licensed devices become a managed, documented, and defensible part of the radiation safety program rather than a latent liability.¹²

How DRPS Can Help

Diagnostic Radiation Physics Services helps facilities bring generally licensed devices into a defensible program with radioactive material license support, device inventory and accountability review, leak-test and registration program setup, end-of-life transfer planning, bone densitometry (DEXA) physics, and radiation safety officer consulting by board-certified medical physicists.

DRPS serves facilities across our service locations, including Florida, Maryland, Virginia, Washington DC, California, Nevada, New York, Pennsylvania, New Jersey, and Delaware. A general license is still a license — the goal is to make sure every device under it is accounted for, tested, and properly retired.

Related Resources

• Sealed source leak testing
• Sealed source inventory and accountability
• Sealed source and device (SSD) registration
• NRC license guide
• NRC, Agreement States, and FDA jurisdiction
• Decommissioning and license termination
• Radioactive material license support
• Radiation Safety Officer consulting

References

1. U.S. Nuclear Regulatory Commission. 10 CFR Part 31: General Domestic Licenses for Byproduct Material (including §31.5). nrc.gov
2. U.S. Nuclear Regulatory Commission. Requirements for Certain Generally Licensed Industrial Devices Containing Byproduct Material. Final rule. 65 Fed. Reg. 79162 (December 18, 2000). federalregister.gov
3. U.S. Nuclear Regulatory Commission. 10 CFR Part 30: Rules of General Applicability to Domestic Licensing of Byproduct Material. nrc.gov
4. U.S. Nuclear Regulatory Commission. 10 CFR Part 32: Specific Domestic Licenses to Manufacture or Transfer Certain Items Containing Byproduct Material. nrc.gov
5. U.S. Nuclear Regulatory Commission. 10 CFR 170.31: Schedule of Fees for Materials Licenses and Other Regulatory Services. nrc.gov
6. U.S. Nuclear Regulatory Commission. Fact Sheet / Information for General Licensees and General License Registration Program. nrc.gov
7. U.S. Nuclear Regulatory Commission. NRC Form 664: General Licensee Registration. nrc.gov
8. National Nuclear Data Center, Brookhaven National Laboratory. NuDat decay data: gadolinium-153 (T½ ≈ 240.4 days). nndc.bnl.gov