PLA-8091, Response to Request for Additional Information Regarding Proposed Relief Request for the Fifth 10-Year Inseervice Inspection Interval (PLA-8091)

Response to Request for Additional Information Regarding Proposed Relief Request for the Fifth 10-Year Inseervice Inspection Interval (PLA-8091)

ML23312A177
Person / Time
Site:	Susquehanna
Issue date:	11/08/2023
From:	Casulli E Susquehanna, Talen Energy
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
PLA-8091
Download: ML23312A177 (1)

Text

Edward Casulli Susquehanna Nuclear, LLC Site Vice President 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.3795 Fax 570.542.1504 TALEN~

Edward.Casulli@talenenergy.com ENERGY November 08, 2023 Attn: Document Control Desk 10 CFR 50.55a U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 SUSQUEHANNA STEAM ELECTRIC STATION RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED RELIEF REQUEST FOR THE FIFTH 10-YEAR INSERVICE INSPECTION INTERVAL Docket No. 50-387 PLA-8091 and 50-388

References:

1) Susquehanna letter to NRC, Proposed Relief Request for the Fifth 10-Year Inservice Inspection Interval (PLA-8073), dated June 01, 2023 (ADAMS Accession No. ML23152A244).

2) NRC letter to Susquehanna, Regulatory Audit Plan in Support of Relief Request 5RR-02 (EPID L-2023-LLR-0027), dated October 19, 2023 (ADAMS Accession No. ML23290A262).

3) NRC email to Susquehanna, NRC Request for Additional Information re.

Susquehanna Steam Electric Station, Units 1 & 2 - Relief Request 5RR-02 (EPID L-2023-LLR-0027), dated October 30, 2023 (ADAMS Accession No. ML23303A166).

Pursuant to 10 CFR 50.55a, Susquehanna Nuclear, LLC (Susquehanna), submitted, in Reference 1, Relief Request 5RR-02, which proposes an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code for inspection of snubber attachments, associated with the Fifth 10-Year Inservice Inspection (ISI)

Interval for Susquehanna Steam Electric Station (SSES), Units 1 and 2.

The NRC notified Susquehanna in Reference 2 of the intent to conduct a virtual regulatory audit.

During the virtual audit, NRC staff reviewed information provided by Susquehanna.

Subsequently, the NRC provided a Request for Additional Information (RAI) in Reference 3.

The enclosure provides Susquehannas response to the RAI.

Document Control Desk PLA-8091 There are no new or revised commitments contained in this submittal.

Should you have any questions regarding this submittal, please contact Ms. Melisa Krick, M ~ c l e a r Regulatory Affairs, at (570) 542-1818.

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E. Casulli

Enclosure:

Response to Request for Additional Information Copy: NRC Region I Mr. C. Highley, NRC Senior Resident Inspector Ms. A. Klett, NRC Project Manager Mr. M. Shields, PA DEP/BRP

Enclosure to PLA-8091 Response to Request for Additional Information

PLA-8091 Enclosure Page 1 of 6 Response to Request for Additional Information On June 01, 2023, Susquehanna Nuclear, LLC (Susquehanna), submitted Relief Request 5RR-02, which proposes an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code for inspection of snubber attachments, associated with the Fifth 10-Year Inservice Inspection (ISI) Interval for Susquehanna Steam Electric Station (SSES), Units 1 and 2 (Reference 1). By letter dated October 19, 2023, the NRC informed Susquehanna of the intent to conduct a virtual regulatory audit (Reference 2). During the virtual audit, NRC staff reviewed information provided by Susquehanna. Subsequently, the NRC provided a Request for Additional Information (RAI) in Reference 3. The response to the RAI is provided below.

RAI-5RR-02-1 (Audit item 001)

ASME BPV Code,Section XI, IWF-2410, Inspection Program, paragraph (b) requires that The required examination [of supports and attachments] shall be completed in accordance with the inspection schedule provided in Table IWF-2410-1, Inspection Program; specifically, inspection period, calendar years of plant service, within the interval (3, 7, and 10 years). Please explain how these supports inspection schedule interval (3, 7, and 10 years) and inspection schedule interval of snubbers by use of OMN-13 (up to 10 years) and supports containing snubbers will be examined and maintained. Please clarify how the licensee plans to align the different inspection intervals under the two different requirements of the ASME Operation and Maintenance (OM)

Code with Code Case OMN-13 and ASME BPV Code,Section XI.

Susquehanna Response As discussed in PLA-8073 Sections 3 and 5, relief is being requested from the periodic inspection requirements of Table IWF-2410-1 for snubber supports only.

Table IWF-2500-1 requires a VT-3 Visual Examination of Class 1 (Fl.10), Class 2 (Fl.20), Class 3 (Fl.30) piping supports, and Class 1, 2, and 3 (Fl.40) component supports. The required percentages to examine for each class are also identified: Class 1 (25% ), Class 2 (15% ), and Class 3 (10% ). The total percentage sample shall be comprised of supports from each system (such as Main Steam, Feedwater, or Residual Heat Removal), where the individual sample sizes are proportional to the total number of non-exempt supports of each type and function within each system. For Fl.40 components, 100% of the supports require examination, unless there are multiple components other than piping within a system of similar design, function, and service, then the supports of only one of the multiple components are required to be examined. Snubber supports fall into all three classes (i.e., Class 1, 2, and 3). These examinations are required to be completed in accordance with IWF-2410-1 at intervals of 3, 7, and 10 years, such that at 3 years

PLA-8091 Enclosure Page 2 of 6 16% of the required examinations are complete, at 7 years 50% of the required examinations are complete and at 10 years 100% of the required examinations are complete.

Susquehanna proposed, as an alternative, that all snubber supports be inspected in accordance with the requirements of OMN-13; specifically, 100% of snubber supports be inspected over the 10-year interval, with an expanded inspection boundary as shown in PLA-8073 Figure 2. Snubber supports would be excluded from the population of supports subject to IWF-2500-1. The population of remaining supports (i.e., non-snubber supports) would be examined at the required sample sizes and periodicity specified by Table IWF-2500-1 and IWF-2410-1, respectively; i.e.

all non-snubber supports will follow existing ASME Section XI IWF requirements.

This alternative would exceed the sample size requirements of Table IWF-2500-1 since 100% of snubber supports would be inspected, while non-snubber Class 1, Class 2 and Class 3 supports would be inspected on a sample basis of 25%, 15%, and 10%, respectively. Non-snubber supports would be inspected on the periodicity defined in IWF-2410-1, while snubber supports would deviate from the interval (i.e., 3, 7, 10 year) requirements of IWF-2410-1 but still require all testing to be complete within the 10-year interval.

RAI-5RR-02-2 (Audit Item 002)

ASME BPV Code,Section XI, IWF-2430(a) states, in part, that component supports examination performed in accordance with Table IWF-2500-1 (F-A) that reveal flaws or relevant conditions exceeding the acceptance standards of IWF-3400, and that requires corrective measures or repair/replacement activities in accordance with IWF-3122.2, shall be extended, during the current outage, to include the component supports immediately adjacent to flawed supports.

Please explain how this situation (to include supports adjacent to flawed supports) will be considered, given that the proposed alternative only considers supports with snubbers. (Note: the adjacent supports could be affected with the snubber.)

Susquehanna Response As stated under PLA-8073 Section 5 Paragraph 4, The requirement found in IWF-2430 to examine the supports immediately adjacent to a snubber that is found exceeding the acceptance standards, and that requires corrective measures or repair/replacement activities, will be

[followed] regardless of whether the adjacent support includes a snubber. The relief requested by Susquehanna is related to the sample size and inspection schedule of snubber supports. This relief would not impact compliance with IWF-2430 for snubber or non-snubber related supports.

PLA-8091 Enclosure Page 3 of 6 RAI-5RR-02-3 (Audit Item 003)

In the Proposed Alternative and Basis for Use section of Request 5RR-02, it is noted that ASME OM Code Case ON-13 requires 100 % of safety related snubbers to be examined and evaluated at least once every 10 years. This exceeds the requirements of the 2019 Edition of the ASME BPV Code,Section XI, Table IWF-2500-1 (F-A), which only requires 25 % of Class 1, 15 % of Class 2, and 10 % of Class 3 supports/attachment over a 10 year interval. Please respond to the following:

A. ASME OM Code Case OMN-13 allows extension of the snubber visual examination once every 10 years and can be implemented after the requirements of ISTD-4251, Initial Examination Interval, and ISTD-4252, Subsequent Examination Interval, have been satisfied and the previous examination per Table ISTD-4252-1, Visual Examination Table, was performed satisfactorily at a maximum interval of two fuel cycles. Describe how the proposed snubber examination extended up to 10 years can be aligned with the 10-year inservice inspection interval of the support and attachments (containing the snubber) for inspection.

B. While using OMN-13 for snubbers during the extended interval of 10-years, if the number of unacceptable snubbers (pin-to-pin) exceeds Table ISTD-4252-1 limits (these unacceptable snubbers can be found during non-inspection activities, such as walkdowns, or any other events, such as water hammer), describe the action that will be taken and how these findings would align with the supports and attachments inspection (section 3.7(b) of OMN-13 requires that if, any time during an examination interval, the cumulative number of unacceptable snubbers exceeds the applicable values from the column in Table ISTD-4252-1, then the current examination interval shall end, and all remaining examinations must be completed within the current cycle).

C. If the number of supports with snubbers exceeds the requirements of ASME BPV Code,Section XI, Table IWF-2500-1 (F-A), will any piping support without snubbers be examined?

Susquehanna Response A. As stated under PLA-8073 Section 2, both the Fifth 10-Year ISI and the Fifth 10-Year Snubber Program Interval begin on June 1, 2024. For each individual support, its respective attachment hardware and snubber inspection requirements under each program will align on day one of the Fifth Interval.

PLA-8091 Enclosure Page 4 of 6 B. As stated under PLA-8073 Section 5 Paragraph 3, in lieu of ASME Section XI IWF-2500-1 requirements, the ASME OM Code for visual inspection of snubbers including ASME OM Code Case OMN-13 will be utilized. This includes the requirement within OMN-13 for snubbers during the extended interval of 10 years, if the number of unacceptable snubbers (pin-to-pin) exceeds Table ISTD-4252-1 limits (these unacceptable snubbers can be found during non-inspection activities, such as walkdowns, or any other events, such as water hammer), then the current examination interval shall end, and all remaining examinations will be completed within the current cycle.

C. As stated under PLA-8073 Section 5 Paragraph 2, examinations of non-snubber supports and their associated attachments will continue to be administered and scheduled per the SSES ISI Program under the requirements of the 2019 Edition of the ASME Section XI Code. Specially, snubber supports would be excluded from the population of supports subject to Table IWF-2500-1, meaning snubber support inspections will not be counted toward the population or sample requirements of Table IWF-2500-1.

RAI-5RR-02-4 (Audit Item 004)

Describe the method of inspection of newly added supports with snubbers, and supports without snubbers, during the 10 year interval, as per Request 5RR-02 (e.g., if the licensee replaces a support or snubber that failed an inspection during the current interval, how would the inspection process be applied to that new support or snubber?). Please describe how the inspection process would apply the alternative proposed in Request 5RR-02 and meet IWF-2410(c).

Susquehanna Response A new snubber support installation considered a repair/replacement activity will have pre-service examinations performed in accordance with IWF-2500-1. Inservice inspections during the Fifth ISI and Snubber interval will be scheduled in accordance with 5RR-02 and OMN-13.

A new non-snubber support installation considered a repair/replacement activity will have pre-service examinations performed in accordance with IWF-2500-1. Inservice inspections during the Fifth ISI and Snubber interval will be scheduled in accordance with IWF-2410(c).

PLA-8091 Enclosure Page 5 of 6 RAI-5RR-02-5 (Audit Item 000)

The NRC staff requests the licensee to provide the information in ID No. 000 from the audit portal regarding the clarification of the scope of the proposed alternative.

Susquehanna Response Susquehanna is requesting relief from the 2019 Edition of ASME Section XI, Table IWF-2500-1, which requires VT-3 Visual Examination of Class 1(F1.10), Class 2 (F1.20), Class 3 (F1.30) piping supports, and Class 1, 2, and 3 (F1.40) component supports. The required percentages to examine for each class of piping supports are identified as: Class 1 (25%), Class 2 (15%), and Class 3 (10%). For F1.40 components, 100% of the supports require examination, unless there are multiple components other than piping within a system of similar design, function, and service, then the supports of only one of the multiple components are required to be examined. The relief is being requested as applied to supports containing snubbers only.

Susquehanna is proposing the alternative of examinations of snubbers and their associated attachments to be administered and scheduled per the SSES Snubber Program under the requirements of the ASME OM Code 2020 Edition. The ASME OM Code Case OMN-13 requires 100% safety related snubbers to be examined and evaluated at least once every 10 years.

The examination method used for the snubber and their attachments will be a VT-3 Visual Examination in accordance with the 2019 Edition of ASME Section XI, IWA-2213. This exceeds the sample size requirements of the 2019 Edition of ASME Section XI, Table IWF-2500-1.

PLA-8091 Enclosure Page 6 of 6 References

1. Susquehanna letter to NRC, Proposed Relief Request for the Fifth 10-Year Inservice Inspection Interval (PLA-8073), dated June 01, 2023 (ADAMS Accession No. ML23152A244).

2. NRC letter to Susquehanna, Regulatory Audit Plan in Support of Relief Request 5RR-02 (EPID L 2023-LLR-0027), dated October 19, 2023 (ADAMS Accession No. ML23290A262).

3. NRC email to Susquehanna, NRC Request for Additional Information re. Susquehanna Steam Electric Station, Units 1 & 2 - Relief Request 5RR-02 (EPID L-2023-LLR-0027),

dated October 30, 2023 (ADAMS Accession No. ML23303A166).