NRC Part 35 Recordkeeping Requirements

A compliant medical-use radiation safety program is only as strong as its records — because in an NRC or Agreement State inspection, an activity that was performed correctly but not documented can still be cited. The recordkeeping duties live in 10 CFR Part 35 Subpart L, backed by Part 20, and each record type carries a specific retention period. Building a records system around those requirements is one of the most effective things a Radiation Safety Officer can do.¹²

Introduction

Nuclear medicine is a heavily documented field, and for good reason: the licensee is handling byproduct material, administering it to patients, and protecting staff and the public. The NRC's medical-use regulation, 10 CFR Part 35, requires the licensee to do many things — determine dosages, calibrate instruments, survey areas, inventory sources, release patients safely — and its Subpart L requires the licensee to keep records proving each was done.¹

Recordkeeping is where many otherwise-solid programs stumble. The work gets done, but the record is missing, incomplete, unsigned, or discarded too early. Because an inspector verifies compliance largely through records, a documentation gap can become a violation even when the underlying practice was correct. Conversely, a clean, well-indexed records system makes an inspection faster, calmer, and more defensible.

This article maps the Part 35 Subpart L recordkeeping requirements most relevant to a nuclear medicine program — which record each activity generates, and exactly how long it must be kept — along with the Part 20 records that apply to every licensee. DRPS helps facilities design and audit these systems through Radiation Safety Officer and radioactive material license support services across Florida, Maryland, Virginia, Washington DC, California, and Nevada.

Topic Explanation

Where the requirements live

The recordkeeping requirements for medical use are collected in 10 CFR Part 35, Subpart L — "Records." Each section in Subpart L corresponds to an operational requirement elsewhere in Part 35. For example, §35.40 requires a written directive, and §35.2040 requires that the written directive be retained; §35.63 requires dosage determination, and §35.2063 requires that the determination be recorded.¹ Learning the pairing — "the doing rule" and "the keeping rule" — is the key to understanding Subpart L.

A frequent point of confusion: Subpart L is Records; Subpart M is Reports. Keeping a record (Subpart L) is not the same as reporting an event to the NRC (Subpart M). A program needs both, but they are different obligations.

Part 20 sits underneath Part 35

Part 35 is the medical-use rule, but it does not stand alone. 10 CFR Part 20 — Standards for Protection Against Radiation — applies to every licensee, and its Subpart L adds recordkeeping that a nuclear medicine program must also satisfy: records of the radiation protection program, surveys, and individual monitoring (occupational dose).² Several Part 20 records are retained until the NRC terminates the license, a longer horizon than most Part 35 records.

For the program-level context these records support, see our overviews of the Radiation Safety Officer role and occupational dose records and NRC reporting.

Key Technical Principles

The Part 35 Subpart L records and their retention periods

The table below lists the Subpart L records most relevant to a nuclear medicine (unsealed byproduct material) program, the requirement each supports, and the retention period specified in the current regulation. Retention periods are exact regulatory values, not rules of thumb.¹

Two patterns are worth memorizing. First, the default for most Part 35 records is 3 years. Second, the exceptions run longer, not shorter: management-authority and program-change records are kept for 5 years (§§35.2024, 35.2026), and the required written procedures for administrations needing a written directive are kept for the duration of the license (§35.2041). No routine nuclear-medicine record is kept for less than 3 years.¹

The Part 20 records that also apply

These longer horizons matter: personnel-dose records, in particular, must persist for the life of the license and are transferred to the NRC when the license is terminated.²

A worked example: decay-in-storage records

Decay-in-storage (§35.92) is a common disposal route for short-lived nuclear medicine waste, and §35.2092 requires records of it. The rule permits holding byproduct material with a physical half-life of less than 120 days until it has decayed, then disposing of it as ordinary waste — but only after monitoring each container at its surface, confirming the reading cannot be distinguished from background (survey meter on its most sensitive scale, with no interposed shielding), and removing or obliterating all radiation labels.¹⁸

The regulation sets a performance standard — decayed to background — rather than a fixed holding time. In practice, facilities plan storage using a rule of thumb of about 10 half-lives, because that reduces activity roughly a thousand-fold. The fraction of activity remaining after $n$ half-lives is:

After 10 half-lives:

so roughly 0.1% of the original activity remains — about a thousand-fold reduction. For a Tc-99m sample (half-life about 6 hours), 10 half-lives is about 60 hours; for I-131 (about 8 days), it is roughly 80 days. The §35.2092 record must document the disposal date, the survey instrument used, the background level, the measured surface reading, and who performed the survey — retained for 3 years. For the operational side, see decay-in-storage of radioactive waste.

Clinical Impact

Records are how the program is judged

An inspector cannot watch a year of dosage determinations or surveys; they read the records. That makes the records the visible surface of the entire program. A department that assays every dose correctly but cannot produce the §35.2063 records has, from the inspection's standpoint, a compliance problem. The record is not paperwork about the work — during an inspection it effectively is the work.

Which records get scrutinized

Certain records draw consistent attention because they map directly to patient and worker safety:

• Written directives and dosage records (§§35.2040, 35.2063) — the core of correct administration and the anchor for detecting a medical event.
• Dose calibrator and survey-instrument records (§§35.2060, 35.2061) — the measurement chain that makes every dosage and survey meaningful. See dose calibrator QC and survey meter calibration.
• Sealed-source leak tests and inventory (§35.2067) — accountability for every sealed source, tied to sealed source leak testing.
• Patient-release records (§35.2075) — the documented basis that a released patient will not exceed the public dose limit, tied to patient release after radiopharmaceutical therapy.

The cost of getting retention wrong

Discarding a record too early is a violation even if the record once existed. Keeping everything forever, on the other hand, creates a different risk: an unmanaged pile of documents in which the required record cannot be found on request. The goal is a system that retains each record for at least its required period and can retrieve it quickly.

Practical Optimization Tips

A records system does not have to be elaborate — it has to be complete, consistent, and retrievable.

1. Build the system around the citations

Organize records by their Subpart L section, not by whoever happened to create them. A folder or database keyed to §35.2040, §35.2063, §35.2067, and so on makes both routine audits and inspections straightforward.

2. Encode the retention period into the record

Stamp each record (or its container) with a "retain until" date computed from its rule: creation date plus 3 years for most, plus 5 years for §§35.2024/35.2026, and "duration of license" or "until license termination" for the long-horizon records. This prevents both premature disposal and indefinite accumulation.

3. Capture signatures and dates the rule requires

Many Subpart L records are only complete with a signature, an effective date, or a specific data element (patient identifier, prescribed versus determined dosage, survey result). An unsigned or undated record can be treated as no record. Confirm each template captures every required field.

4. Keep electronic records to the Part 20 form standard

Electronic recordkeeping is permitted, but records must be legible, retrievable, and protected from alteration or loss, consistent with the "form of records" requirements. Back them up, control access, and be able to reproduce them on request.

5. Audit the records at the annual program review

The RSO's periodic review of the program is the natural time to sample records against the Subpart L list, confirm retention dates, and fix gaps before an inspector finds them. Pair this with the broader annual radiation protection program audit.

Common pitfalls to avoid

• Confusing records with reports. Subpart L (records) and Subpart M (reports) are separate obligations.
• Applying a single retention period to everything. Most records are 3 years, but 5-year and duration-of-license exceptions exist.
• Discarding personnel-dose records early. Part 20 individual-monitoring records run until license termination.
• Incomplete records. Missing signatures, dates, or data elements can invalidate an otherwise-good record.
• No retrieval plan. A record you cannot find during an inspection is, for that purpose, a record you do not have.

Regulatory Considerations

Medical-use recordkeeping is governed by 10 CFR Part 35 Subpart L, the Part 20 records subpart, the facility's license conditions, and — in Agreement States — the compatible state program. The records support, and are inseparable from, the operational requirements they document.¹²

Key frameworks:

• 10 CFR Part 35, Subpart L — Records. The medical-use recordkeeping requirements and their retention periods.¹
• 10 CFR Part 20, Subpart L — Records. Program, survey, and individual-monitoring records that apply to all licensees, several retained until license termination.²
• NRC NUREG-1556, Volume 9. Program-specific guidance for medical-use licenses; the current revision consolidates NRC expectations for records, procedures, and program elements.³

Jurisdiction determines who you answer to. The NRC regulates byproduct material directly in non-Agreement States and areas of federal jurisdiction; among the states DRPS serves, Washington, DC and Delaware are direct-NRC (non-Agreement), while Florida, Maryland, Virginia, California, Nevada, Pennsylvania, New York, and New Jersey are NRC Agreement States administering compatible programs. Agreement State retention requirements are generally equivalent, but the licensee should confirm the exact citations and any state-specific additions with its licensing authority.⁴ DRPS supports this through radioactive material license support and helps facilities prepare for inspections.

Frequently Asked Questions (FAQs)

What is 10 CFR Part 35 Subpart L?

Subpart L is the "Records" subpart of the NRC's medical-use regulation, 10 CFR Part 35. It lists the records a medical-use licensee must create and keep — for example written directives, dosage determinations, instrument calibrations, surveys, sealed-source inventories, and patient-release bases — and specifies how long each must be retained.

How long must a medical-use licensee keep records?

It depends on the record. Most Part 35 records are kept for 3 years, records of management authority and program changes are kept for 5 years, and some records — such as the procedures required for administrations needing a written directive — are kept for the duration of the license. Certain source records run for the life of the source.

How long are written directive records kept?

Under 10 CFR 35.2040, a licensee must retain a copy of each written directive for 3 years. The related procedures for administrations that require a written directive, under 35.2041, are kept for the duration of the license.

How long must patient-release records be kept?

Under 10 CFR 35.2075, records that support authorizing the release of a patient containing unsealed byproduct material or an implant — including instructions given to a breast-feeding patient — are retained for 3 years after the date of release.

Do Part 20 records also apply to a nuclear medicine license?

Yes. 10 CFR Part 20 Subpart L adds recordkeeping that spans all licensees, including records of the radiation protection program, surveys, and individual monitoring (occupational dose). Several Part 20 records must be kept until the NRC terminates the license, not for a fixed number of years.

What happens if records are missing during an inspection?

Missing or incomplete records are among the most common findings in NRC and Agreement State inspections. Because inspectors verify compliance largely through records, an activity that was performed correctly but not documented can still result in a violation. A well-organized records system is a core part of a defensible program.

Are Agreement State recordkeeping requirements the same?

They are compatible but administered by the state. Agreement States adopt requirements compatible with the NRC's, so retention periods are generally equivalent, but the licensee answers to the state program. Facilities should confirm the exact citations and any state-specific additions with their licensing authority.

Key Takeaways

• Subpart L pairs a "keep" rule with each "do" rule. Every operational requirement in Part 35 generates a corresponding record.¹
• Most Part 35 records are retained 3 years. The exceptions run longer: 5 years for management-authority and program-change records, and duration of the license for the written procedures under §35.2041.¹
• Patient-release records are kept 3 years after release under §35.2075, including breast-feeding instructions.¹
• Part 20 records reach further. Program, survey, and individual-monitoring records under Part 20 Subpart L run until license termination.²
• Records are the inspection surface. Undocumented compliant work can still be cited; organize by citation, encode retention dates, and audit annually.
• Agreement States are compatible but separate. Confirm exact citations with your licensing authority.⁴

Conclusion

Recordkeeping is not the glamorous part of a radiation safety program, but it is the part an inspector sees first and judges hardest. The Part 35 Subpart L requirements are not arbitrary — each record proves that a safety-relevant task was actually performed, by whom, and when. Add the Part 20 records that run for the life of the license, and the shape of a compliant system becomes clear.

The most resilient programs treat records as a designed system: organized by regulatory citation, stamped with retention dates, complete in every required field, retrievable on demand, and audited before an inspector arrives. Build that once, maintain it deliberately, and recordkeeping shifts from a source of findings to a demonstration that the program works.

How DRPS Can Help

Diagnostic Radiation Physics Services helps medical-use licensees build and audit compliant records systems: mapping Subpart L and Part 20 requirements to the facility's workflow, designing record templates that capture every required field, setting retention schedules, and running mock-inspection record audits. This is delivered through Radiation Safety Officer consulting, radioactive material license support, and medical physics consulting.

DRPS supports facilities across our service locations, including Florida, Maryland, Virginia, Washington DC, California, Nevada, New York, Pennsylvania, New Jersey, and Delaware.

Related Resources

• The Radiation Safety Officer role
• Occupational dose records and NRC reporting
• Written directives in nuclear medicine
• Decay-in-storage of radioactive waste
• Patient release after radiopharmaceutical therapy
• Preparing for an NRC inspection
• Radiation Safety Officer services
• Radioactive material license support

References

1. U.S. Nuclear Regulatory Commission. 10 CFR Part 35, Subpart L — Records (Medical Use of Byproduct Material). ecfr.gov
2. U.S. Nuclear Regulatory Commission. 10 CFR Part 20, Subpart L — Records (Standards for Protection Against Radiation). ecfr.gov
3. U.S. Nuclear Regulatory Commission. NUREG-1556, Volume 9, Revision 3: Consolidated Guidance About Materials Licenses — Program-Specific Guidance About Medical Use Licenses. September 2019. nrc.gov
4. U.S. Nuclear Regulatory Commission. 10 CFR 35.2075 — Records of the release of individuals containing unsealed byproduct material or implants containing byproduct material. ecfr.gov
5. U.S. Nuclear Regulatory Commission. 10 CFR 35.2040 — Records of written directives. ecfr.gov
6. U.S. Nuclear Regulatory Commission. 10 CFR 35.2063 — Records of dosages of unsealed byproduct material for medical use. ecfr.gov
7. U.S. Nuclear Regulatory Commission. 10 CFR 35.2067 — Records of leak tests and inventory of sealed sources and brachytherapy sources. ecfr.gov
8. U.S. Nuclear Regulatory Commission. 10 CFR 35.92 — Decay-in-storage. ecfr.gov
9. U.S. Nuclear Regulatory Commission. 10 CFR 20.2106 — Records of individual monitoring results. ecfr.gov
10. U.S. Nuclear Regulatory Commission. Backgrounder on Agreement States. nrc.gov