Nuclear NDT personnel qualification: Appendix B, ASME XI and CP-189

Nondestructive testing (NDT) at a nuclear plant sits under more layers of rule than anywhere else in the industry. A technician qualified to SNT-TC-1A in a fabrication shop can be excellent at the method and still not be qualified for the same examination on a reactor coolant weld, because the qualification there answers to a federal quality regulation, a code the regulation incorporates by reference, and conditions the regulator attaches to that code.

This guide walks down those layers — 10 CFR 50 Appendix B, 10 CFR 50.55a and ASME Section XI, CP-189, the old ANSI N45.2.6 and today's NQA-1, and 10 CFR Part 21 — and ends with the personnel records they expect to see.

Layer one: 10 CFR 50 Appendix B

Appendix B to 10 CFR Part 50 sets eighteen quality assurance criteria for nuclear power plants and fuel reprocessing plants. It is written to the applicant or licensee, but Criterion I lets the licensee delegate the work of its program to contractors, agents or consultants while keeping responsibility for it. Criterion IV then requires procurement documents to carry the applicable requirements down to contractors and subcontractors, including, where necessary, a quality assurance program consistent with Appendix B. That is how an NDT company ends up under it.

The eighteen criteria, in order:

1. Organization
2. Quality Assurance Program
3. Design Control
4. Procurement Document Control
5. Instructions, Procedures, and Drawings
6. Document Control
7. Control of Purchased Material, Equipment, and Services
8. Identification and Control of Materials, Parts, and Components
9. Control of Special Processes
10. Inspection
11. Test Control
12. Control of Measuring and Test Equipment
13. Handling, Storage and Shipping
14. Inspection, Test, and Operating Status
15. Nonconforming Materials, Parts, or Components
16. Corrective Action
17. Quality Assurance Records
18. Audits

Four of them do most of the work for NDT personnel.

Criterion II: training

The program must provide indoctrination and training for people doing activities affecting quality, so that suitable proficiency is achieved and maintained. “Maintained” is the word that turns a one-off certification into a recurring obligation.

Criterion IX: Control of Special Processes

This is the criterion that names NDT. It requires measures to make sure special processes — it lists welding, heat treating and nondestructive testing — are controlled and carried out by qualified personnel using qualified procedures, in line with the applicable codes, standards and specifications. Appendix B does not say what “qualified” means for an examiner. It hands that question to the codes and standards, which is where the next layers come in.

Criterion X: Inspection

Inspection must be done by someone other than the person who did the work being inspected. For a small crew that both performs and verifies work, this independence has to be visible on the records.

Criterion XVII: Quality Assurance Records

Records must be sufficient to furnish evidence of activities affecting quality, and the criterion expressly includes the qualifications of personnel, procedures and equipment. Inspection and test records must at least identify the inspector or data recorder, the type of observation, the results, the acceptability and the action taken on any deficiency. Records must be identifiable and retrievable, and the licensee sets retention — how long, where and who is responsible. A certification you cannot find, or cannot tie to the examination it supported, fails this criterion even if the person was qualified.

Layer two: 10 CFR 50.55a and ASME Section XI

Section 50.55a incorporates the ASME Boiler and Pressure Vessel Code into the regulation by reference. Paragraph (a)(1)(ii) lists the editions and addenda of Section XI the NRC has approved; in the text current on eCFR in September 2026 the list runs up to the 2021 Edition. Paragraph (g)(4) then requires Class 1, 2 and 3 components at operating boiling and pressurized water reactors to meet Section XI inservice inspection requirements throughout their service life, to the extent practical. Each plant has a Section XI “code of record”, and at the start of each successive inspection interval it moves to the latest edition incorporated in the regulation no more than 18 months before that interval begins.

The practical result: the edition you qualify to is the plant's, not the newest one on the shelf, and it changes on the plant's schedule.

The NRC's conditions on personnel

Section 50.55a approves Section XI subject to conditions in paragraph (b)(2), and several of them are about people:

• Three-year recertification. Under (b)(2)(xviii)(A), Level I and Level II personnel must be recertified every three years rather than the five years in Section XI's IWA-2314, for the 2001 Edition onward. A nuclear Level II's clock therefore runs shorter than the same person's general-industry certification.
• Annual hands-on training for ultrasonic performance demonstration. Under (b)(2)(xiv), personnel qualified to perform ultrasonic examinations under Section XI Appendix VIII must receive 8 hours of hands-on training each year on specimens that contain cracks, or use the Appendix VII practice alternative the condition describes. Either way it must be completed no earlier than 6 months before they examine at a licensee's facility.

Appendix VIII itself is the reason nuclear ultrasonic qualification looks unlike anything else: procedures, equipment and personnel are qualified together by performance demonstration, rather than by hours and written exams alone.

Layer three: CP-189, through Section XI

Section XI's personnel qualification rules sit in Article IWA-2300 and build on ASNT's CP-189, the ANSI-approved standard whose requirements apply as written rather than as a starting point for the employer to adapt. The employer still certifies, against a written practice, but the written practice has less room to move than one built on SNT-TC-1A, and Section XI and 50.55a add their own requirements on top. The CP-189 guide covers the standard itself, and the ASME Section V and XI guide covers how the two code sections divide the work.

ANSI N45.2.6: where it went

Before NQA-1 existed in its current form, inspection personnel at nuclear plants were qualified to ANSI N45.2.6, “Qualifications of Inspection, Examination, and Testing Personnel for Nuclear Power Plants”. The 1978 edition was prepared by a working group of the ASME Committee on Nuclear Quality Assurance and approved by ANSI in August 1978. It set three levels of capability and covered inspection, examination and testing from fabrication through operation.

NRC Regulatory Guide 1.58, Revision 1 (September 1980) endorsed ANSI N45.2.6-1978 as an acceptable basis for meeting Appendix B, with exceptions. Two of its positions matter to NDT people. First, the standard itself said it was not intended for personnel who only perform NDT under SNT-TC-1A, and the guide accepted SNT-TC-1A for those methods. Second, for examinations required by ASME Sections III and XI, the guide said SNT-TC-1A should be used together with the Code's additional provisions. N45.2.6 was aimed at the wider population of inspectors and testers the codes do not reach.

In July 1991 the NRC withdrew Regulatory Guide 1.58, and five others, as obsolete: the ANSI standards they endorsed had been incorporated into ANSI/ASME NQA-1-1983, which Regulatory Guide 1.28 Revision 3 (August 1985) endorsed. The withdrawal notice says it does not alter existing licensing commitments. That is why you will still meet N45.2.6 in the quality program of an older plant, and why a contractor can be asked to qualify inspection personnel to it today.

NQA-1 and Appendix B

Appendix B is the regulation. It says what a quality program must achieve and leaves the how open. ASME NQA-1, “Quality Assurance Requirements for Nuclear Facility Applications”, is a consensus standard that fills in the how, and the NRC tells licensees which editions it will accept:

• Regulatory Guide 1.28, Revision 6 (September 2023) endorses the Part I and Part II requirements of NQA-1-2017, NQA-1-2019 and NQA-1-2022, with clarifications and exceptions, for the design and construction phases of nuclear power plants and fuel reprocessing plants. Revision 5 had endorsed NQA-1-2008 with the 2011 addenda, NQA-1-2012 and NQA-1-2015.
• 10 CFR 50.55a separately incorporates NQA-1 editions from 1983 through 2015 by reference, and lets a licensee applying Section XI use an incorporated edition that Section XI itself cites — always together with its Appendix B program, never instead of it.

Regulatory guides are not regulations. Regulatory Guide 1.58 said so in its own boilerplate: compliance is not required, and other methods are acceptable if they support the findings the NRC has to make. In practice, though, a licensee commits to a particular guide and edition in its quality assurance program description, and from then on that commitment is what it is inspected against — and what it flows down to you in the purchase order.

10 CFR Part 21: the service is the component

Part 21 is the defect reporting rule, and NDT companies tend to assume it is about hardware. It is not only that. Section 21.3 defines a basic component to include safety-related inspection, testing and consulting services associated with the component hardware, whether the component supplier performs them or someone else does. Section 21.31 requires procurement documents to say when Part 21 applies.

If yours does, you need a way to evaluate deviations, and to get anything that could create a substantial safety hazard to a director or responsible officer who can notify the NRC. An evaluation that cannot be finished within 60 days of discovery calls for an interim written report. Section 21.51 then sets retention: evaluations of deviations and failures to comply for at least five years, and, for suppliers of basic components, notifications to purchasers for five years and a record of purchasers for ten years after delivery.

The numbers in one place

What the personnel file needs to show

Put the layers together and a nuclear examiner's qualification file has to answer more than “is the certificate current”. An auditor working from Criterion XVII will want to trace:

• the certification for each method and level, with the written practice and edition it was issued under;
• recertification dates on the nuclear cycle, which for Level I and II under Section XI is three years, not five;
• training, experience and examination records behind each certification, including performance demonstration results for Appendix VIII ultrasonic work and the annual hands-on training that keeps it usable;
• vision examinations on the interval the governing edition requires;
• the link from each examination record to the qualified person and qualified procedure used, so Criterion IX can be shown rather than asserted;
• and, where Part 21 is in the purchase order, your deviation evaluations and the records section 21.51 requires.

A technician who also works general industry carries two sets of clocks: a three-year nuclear recertification beside a five-year SNT-TC-1A one, with different written practices behind them. Keep them as separate certifications rather than one record with a note. The vision exam guide and the quality system guide go further on the annual checks and the program around them.

Frequently asked questions