ML24190A028

Presentation - Construction Exam and PSI Rules

ML24190A028
Person / Time
Issue date:	07/28/2024
From:	Michael Benson, John Honcharik, David Rudland NRC/NRR/DNRL/NPHP, NRC/NRR/DNRL/NVIB
To:
Benson, M., NRR/DNRL, 301-415-2425
References
PVP2024-123483
Download: ML24190A028 (15)

Text

PVP2024-123483:

Construction Rules, Preservice Inspection Rules, and Nuclear Safety Michael Benson, John Honcharik, and David Rudland 2024 Pressure Vessels and Piping Conference Bellevue, WA July 28 - August 2, 2024

Disclaimer This presentation was prepared as an account of work sponsored by an agency of the U.S.

Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third partys use, or the results of such use, of any information, apparatus, product, or process disclosed in this presentation, or represents that its use by such third party would not infringe privately owned rights. The views expressed in this paper are not necessarily those of the U.S. Nuclear Regulatory Commission.

11-16 June 2023 ICF-15 2

Implementation of Construction Rules

• Various stakeholders (are they on the same page?)

- Owner

- Certificate Holder

- Regulator

• Subtleties

- What does the ASME Certification Mark signify?

- When doesSection III end and Section XI begin?

- How does licensing impact implementation of Code rules?

• Lack of common understanding wastes time and resources

- Regulatory enforcement actions

- Misinformed planning and decision-making

- Inconsistent practice across the industry 3

Overview of Section III Rules

• Component classification

• Certificate of Authorization

• ASME Certification Mark

• Reports: e.g, Design Specification

• Examination and Testing

• Flaw Acceptance 4

Section III Examination Rules

• Complete set of examination rules depends on the component

• Often, a volumetric technique + a surface technique

• Radiography applied to satisfy the volumetric requirement

• The Design Specification identifies components that require Section XI preservice inspection (PSI)

• Section XI and 10 CFR 50.55a(g) describe further which components require PSI

• Key point: Section III invokesSection XI 5

Also see NCA-8310(a) and NCA-8321 on satisfactory completion of all examinations, tests, and inspections

Section XI PSI Rules

• All components subject to inservice inspection rules of Section XI must also undergo PSI

• Section XI PSI rules apply to both new construction and repaired/replaced components

• Ultrasonic technique is applied for Section XI PSI Less impact on outage activities than radiography Optimized for finding service-induced flaws 6

Flaw Acceptance

• Section III NB-5300, for example, provides standards for construction code exams

- e.g., Cracks and incomplete fusion not acceptable for radiographic examination results

• For PSI, the applicable Section XI acceptance standards must be met

• Otherwise, the component is not acceptable for service and shall be repaired (NB-5332)

• 10 CFR 50.55a(b)(2)(xli) prohibits use of analytical evaluation for acceptance of flaws found during PSI 7

Licensing

• 10 CFR 50 and 10 CFR 52 provide separate licensing paths

- Part 50: two-step licensing

- Part 52: one-step licensing with inspections, tests, and acceptance criteria (ITAAC)

• Part 50: Section III governs during the construction permit and Section XI governs during the operating license

• Part 52: Section III governs up until the 10 CFR 50.103(g) finding

• However,Section III referencesSection XI, so certain Section XI rules apply when Section III governs 8

10 CFR 50 10 CFR 52 i.e.,Section III and Section XI are not entirely independent

Potential Lessons from this Review of the Rules 9

NDE Techniques

• Radiography to satisfy the construction code requirement is optimized for fabrication flaws

- Lack of fusion

- Porosity

• Ultrasonic to satisfy the PSI requirement is optimized for service-related degradation (i.e., cracks)

• Application of diverse techniques is valuable for nuclear safety

Reference:

NUREG/CR-7204 (ML15253A674) 10

Significance of ASME Certification Mark

• Application of the ASME stamp represents the Certificate Holders view that all the requirements of Section III have been met

• There must be independent verification of the Certificate Holders claim

- The Owner must verify through signing the N-3 Data Report

- The Regulator must verify through regulatory processes, such as ITAAC closure

• The component and the plant are deemed acceptable for service only after appropriate independent verification takes place 11

Relationship between Sections III and XI

• There is no conflict between the construction code exam rules and the Section XI PSI rules

• Both sets of rules are diverse and complimentary, contributing to nuclear safety

• Section III refers to Section XI PSI rules, so a subset of Section XI rules must be followed as part of construction activities

• Licensing plays a role in determining when Section III no longer governs 12 See slide 8

The Role of Flaw Acceptance Criteria

• Section III and Section XI acceptance criteria are developed independent of a particular Owner or a particular scenario at a construction site

• Such criteria promote standardized practices across the U.S. nuclear industry

• Such criteria provide stakeholder confidence in engineering decisions by the Owner 13

Conclusions

• Establishing a common understanding of current rules governing construction of nuclear power plants is vital for deployment of new nuclear

• Effective modification of the rules also requires a common understanding of the current rules

• The construction code and PSI exam rules both play important, complementary roles for nuclear safety

• Objective, independent rules foster confidence in Owner decision-making 14

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