ML23270B836

Code Case N-752 Audit September 26, 2023, E-mail Providing Additional Information Regarding the Use of Owner'S Requirements and Engineering Judgment in Lieu of Code and Standards

ML23270B836
Person / Time
Site:	Oconee
Issue date:	09/26/2023
From:	Vaughan J Duke Energy Carolinas
To:	Shawn Williams NRC/NRR/DORL/LPL2-1
Williams S
References
EPID L-2022-LLR-0060
Download: ML23270B836 (1)

Text

From: Vaughan, Jordan L To: Shawn Williams Cc: Varnedoe, Jennifer Maye

Subject:

[External_Sender] Duke Follow-up on Code Explanation and Owners Requirements Date: Tuesday, September 26, 2023 4:27:53 PM Attachments: Owners Requirements Discussion_Final.pdf

Shawn, See attached. As discussed earlier today, Duke is comfortable with this information being made publicly available (including this e-mail) and referenced in the Audit Summary.

This write-up has also been added to the Certrec Portal for the reviewers.

Jordan

Concerns expressed by NRC

1. An owner could use Owner's Requirements to establish all the requirements for an item and completely circumvent use of Construction Codes

2. Use of may/shall in the case and submittal permit use of engineering judgment in lieu of code and standards Duke Response:

Owner's Requirements is a defined term with specific meaning in Section XI that distinguishes Owners Requirements from Code requirements, establishing two separate sets of requirements. This is a Section XI convention that exists in the base code editions/addenda and was implemented in Code Case N-752 and the Oconee submittal to retain consistency with code editions/addenda in use in the industry.

In laymans terms, the Design Specification requirements for an item are comprised of code requirements, regulatory requirements (e.g. conditions applicable to a construction code), and Owner's Requirements.

Duke submittal paragraph 5.2.E.4, patterned after Code Case N-752, -1420(d), states:

Items used for repair/replacement activities shall meet the Owners Requirements or revised Owners Requirements as permitted by the licensing basis.

Duke submittal paragraph 5.2.E.5, patterned after Code Case N-752, -1420(e), states:

Items used for repair/replacement activities shall meet the Construction Code to which the original item was constructed. Alternatively, items used for repair/replacement activities shall meet the technical requirements of a nationally recognized code, standard, or specification applicable to that item as permitted by the licensing basis.

Application:

Paragraph 5.2.E.4 establishes the Owners Requirements for items to be used for repair/replacement under Code Case N-752. Since Owner's Requirements is given specific meaning distinct from Code requirements, paragraph 5.2.E.5 is needed to establish code requirements for an item to be used for replacement under Code Case N-752. The two sets of requirements comprise a full set of requirements for an item, Owners and Code Requirements. Submittal paragraphs 5.2.E.4 and 5.2.E.5 are parallels to the 2017 edition of ASME Section XI, IWA-4221, Construction Code and Owners Requirements which describes use of Owners and Code requirements. These two paragraphs are consistent with current Section XI code requirements.

Paragraph 5.2.E.4 is met by either meeting the original Owner's Requirements for the item or revised Owner's Requirements. This paragraph does not discuss use of Owner's Requirements in lieu of Code requirements and does not grant any permissions in that regard. Revised Owner's Requirements must be evaluated as required by 5.2.E.3.

Paragraph 5.2.E.5 requires that replacement items meet the original Construction Code or, alternatively, technical requirements of a nationally recognized code, standard, or specification applicable to that item as permitted by the licensing basis. Thus, Owner's

Requirements cannot wholly replace Construction Code requirements because items must meet one of these two 5.2.E.5 requirements (original construction code or alternate code).

The continued use of distinct Owners and Code requirements in Code Case N-752 and the submittal has been similarly established in code edition/addenda, and the specific requirements provided for each to prevent indiscriminate substitution of Owners Requirements for Code requirements.

Code Case N-752 does provide two specific owner permissions and similar permissions are requested in the submittal in paragraphs 5.2.E.7 and 5.2.E.8 which will be discussed below.

Duke submittal paragraph 5.2.E.6, patterned after Code Case N-752, -1420(f), states:

The repair methods of nationally recognized post-construction codes and standards (e.g., PCC-2, API-653) applicable to the item may be used.

Application:

This paragraph allows the use of nationally recognized post-construction codes and standards applicable to the item. The word shall is not used because shall would establish that these nationally recognized post-construction codes and standards must be used. The use of the word may retains the flexibility to use Section XI code, if desired or if there is not a nationally recognized post-construction codes or standard applicable to the item.

Duke submittal paragraph 5.2.E.7, patterned after Code Case N-752, -1420(g), states:

Performance of repair/replacement activities, and associated nondestructive examination (NDE), shall be in accordance with the Owners Requirements and, as applicable, the Construction Code, or postconstruction code or standard, selected for the repair/replacement activity. Alternative examination methods may be used as approved by the Owner. NDE personnel may be qualified in accordance with IWA2300 in lieu of the Construction Code.

Duke submittal paragraph 5.2.E.8, patterned after Code Case N-752, -1420(h), states:

Pressure testing of the repair/replacement activity shall be performed in accordance with the requirements of the Construction Code selected for the repair/replacement activity or shall be established by the Owner.

Application:

Paragraph 5.2.E.7 states that performance of repair/replacement activities (reference IWA-4110b) will have both the Owners Requirements and either the Construction Code, or postconstruction code or standard, selected for the repair/replacement activity. The activities (e.g. welding, brazing, defect removal, procurement, design, fabrication, installation, examination and pressure testing of items) will follow a nationally recognized Construction Code, or postconstruction code or standard similar to the requirement in submittal paragraph 5.2.E.5.

It also allows alternate NDE examination methods which are discussed below along with paragraph 5.2.E.8.

These paragraphs (the NDE portion of 5.2.E.7 and all of 5.2.E.8) permit specific alternatives to the code or standard, but not wholesale use of Owners Requirements to substitute for code requirements. Paragraph 5.2.E.7 allows for alternative NDE methods and 5.2.E.8 allows for pressure testing requirements to be determined by the owner.

However, these permissions are also subject to paragraph 5.2.E.3, which states:

Changes in configuration, design, materials, fabrication, examination, and pressure-testing requirements used in the repair/replacement activity shall be evaluated, as applicable, to ensure the structural integrity and leak tightness of the system are sufficient to support the design bases functional requirements of the system.

Duke submittal paragraph 5.2.E.9, patterned after Code Case N-752, -1420(i), states in part:

Baseline examination (e.g., preservice examination) of the items affected by the repair/replacement activity, if required, shall be performed in accordance with requirements of the applicable program(s) specifying periodic inspection of items.

Application:

In paragraph 5.2.E.9, the if required statement pertains to the scoping of the preservice ISI or IST examinations. The ASME Code Case N-752 LSS components may, or may not, be within the scope of those programs. If the ASME Code Case N-752 LSS components are not within the scope of those programs, then the examinations are not required. If the ASME Code Case N-752 LSS components are within the scope of those programs, then the examinations are determined by the program requirements.

Duke submittal paragraph 5.2.E.16 states:

As permitted by Code Case N-752, Duke Energy intends to implement the exemption on IWA-4000 applicable to repair/replacement activities. Article IWA-4000 of the ASME Section XI Code specifies administrative, technical, and programmatic requirements for performing repair/replacement activities on pressure-retaining items and their supports. As specified in IWA-4110(b), repair/replacement activities "include welding, brazing, defect removal, metal removal by thermal means, rerating, and removing, adding, and modifying items or systems.

These requirements are applicable to procurement, design, fabrication, installation, examination, and pressure testing of items within the scope of this Division". In lieu of these IWA-4000 requirements, Duke Energy will perform repair/replacement activities on LSS items in accordance with an Owner-defined program that complies with paragraph -1420 of Code Case N-752. The Duke Energy program will utilize existing Duke Energy processes such as those applicable to procurement, design, re-rating, fabrication, installation, modifications, welding, defect removal, metal removal by thermal processes and supplement those process requirements as necessary to comply with Code Case N-752. Duke Energy believes this program will ensure, with reasonable confidence, that LSS items remain capable of performing their safety-related functions under design basis conditions. Finally, the exemption of IWA-4000 requirements and the alternative use of Owner-defined treatment requirements for LSS items is consistent with the NRCs position on risk- informed programs as specified in 10 CFR 50.69(b)(1)(v) and (d)(2).

Application:

This paragraph is stating Duke will use existing infrastructure (e.g. Welding Program, Design Control, Procurement, procedures and practices, etc.) to implement Code Case N-752. Specifically, how the activities listed in paragraph 5.2.E.16 would be completed are addressed in items 5.1.E 1-17.

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Conclusion:==

Select repair/replacement tasks (e.g. NDE methods, pressure testing) allow the Owner to establish requirements for the activity. Code Case N-752 requires that repair / replacement activities on LSS items follow a nationally recognized Construction Code, or post-construction code or standard, with the possible exception of Owner defined NDE methods and pressure testing. These requirements confirm, with reasonable confidence, that each LSS item will remain capable of performing its safety-related functions under design-basis conditions.

Furthermore, the Owner is required to ensure the structural integrity and leak tightness of the system are sufficient to support the design basis functional requirements of the system.

Condition monitoring programs (e.g. Technical Specifications, RI-ISI, License Renewal Aging Management, etc.) remain in effect to provide continued assurance that unknown degradation of these pressure retaining items is not occurring. Further, these condition monitoring programs monitor for operational leakage, which has the effect of ensuring Technical Specification structures, systems, and components remain operable and able to perform their safety function.

Finally, LSS categorized components that are classified as ASME BPV Code Class 2 and 3, and are required to be operable by plant Technical Specifications, will be treated in accordance with the licensees approved relief request requirements (aka in accordance with Code Case N-752). Even though the categorization process assumes a failure probability of 1.0 and shows that failure of these LSS SSCs will have a negligible impact on public health and safety, the relief request requires that, with reasonable confidence, LSS SSCs remain capable of performing their safety related functions under design basis conditions.