PLA-8113, Response to Request for Additional Information Regarding Relief Request 4RR-11 (PLA-8113)

Response to Request for Additional Information Regarding Relief Request 4RR-11 (PLA-8113)

ML24102A022
Person / Time
Site:	Susquehanna
Issue date:	04/11/2024
From:	Casulli E Susquehanna, Talen Energy
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
PLA-8113
Download: ML24102A022 (1)

Text

Edward Casulli Susquehanna Nuclear, LLC Site Vice President 769 Salem Boulevard Berwick, PA 18603 TALEN~

Tel. 570.542.3795 Fax 570.542.1504 Edward.Casulli@TalenEnergy.com ENERGY

April 11, 2024

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 RELIEF REQUEST 4RR-11 PLA-8113 Docket No. 50-387

References:

1) Susquehanna letter to NRC, "Relief Request 4RR-11 Relief Request from End of Interval Boundary Leakage Test (PLA-8112)," dated April 09, 2024 (ADAMS Accession No. ML24100A832).

2) NRC email to Susquehanna, "Request for Additional Information for Susquehanna Unit 1 Alternative Request 4RR-ll," dated April 10, 2024.

In accordance with 10 CFR 50.55a(z), Susquehanna Nuclear, LLC (Susquehanna), in Reference 1, requested NRC approval of relief request 4RR-l 1 associated with the fourth and fifth 10-year Inservice Inspection intervals for the Susquehanna Steam Electric Station, Unit 1.

Relief request 4RR-11 requested authorization of alternative requirements for the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, IWB-5222(b) pressure boundary test for the volume between the inboard (IB) and outboard (OB) main steam isolation valves (MSIVs) on the 'D' main steam line (MSL). This request would defer the pressure test between the IB and OB MSIVs on the 'D' MSL until the next Unit 1 refuel and inspection outage (projected for spring 2026).

The NRC provided a Request for Additional Information (RAI) in Reference 2. The enclosure provides Susquehanna's response to the RAI.

Susquehanna requests authorization of the proposed alternative by April 12, 2024.

There are no new or revised regulatory commitments contained in this submittal.

- 2 - Document Control Desk PLA-8113

Should you have any questions regarding this submittal, please contact Ms. Melisa Krick, Manager-Nuclear Regulatory Affairs, at (570) 542-1818.

E. Casulli

Enclosure:

Response to Request for Additional Information

Copy: NRC Region I Ms. J. England, NRC Senior Resident Inspector Ms. A. Klett, NRC Project Manager Mr. M. Shields, PA DEP/BRP Enclosure to PLA-8 113

Response to Request for Additional Information

Enclosure to PLA-8113 Page 1 of 3

Response to Request for Additional Information

On April 09, 2024, Susquehanna Nuclear, LLC (Susquehanna), submitted a relief request, 4RR-11, associated with the Class 1 boundary leakage test required by American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code),Section XI, IWB-5222(b). Specifically, 4RR-11 requested authorization of alternative requirements for the IWB-5222(b) pressure boundary test for the volume between the inboard (IB) and outboard (OB) main steam isolation valves (MSIVs) on the D main steam line (MSL). This request would defer the pressure test between the IB and OB MSIVs on the D MSL until the next Unit 1 refuel and inspection outage (RIO) (projected for spring 2026). Subsequently, the NRC provided a Request for Additional Information (RAI) in Reference 2. The response to this RAI is provided below.

RAI-1

Section 3, Applicable Code Requirement, of [Reference 1] states, ASME Code,Section XI, Section XI, IWB-5222(b) requires the system leakage test pressure retaining boundary to extend to all Class 1 components. However, the alternative is taking exception to the specific ASME Code requirement that system leakage test be performed at or near the end of the interval per IWB-5222(b). Therefore, the staff requests the licensee to discuss the specific requirement to which the alternative is taking exception, in this section of the submittal.

Susquehanna Response

Section 3 below replaces Section 3 of Reference 1 in its entirety. This replacement does not alter the remaining content of Reference 1.

3. Applicable Code Requirement

The ASME Code,Section XI, IWB-5222(b) requires the system leakage test pressure retaining boundary to extend to all Class 1 components within the system boundary.

Specifically, IWB-5222(b) states,

The Class 1 pressure retaining boundary which is not pressurized when the system valves are in the position required for normal reactor startup shall be pressurized and examined at or near the end of the inspection interval. This boundary may be tested in its entirety or in portions and testing may be performed during the testing of the boundary of IWB-5222(a).

The ASME Code,Section XI, Table IWB-2500 -1, Item No. B15.20 requires that pressure retaining components subject to IWB-5222(b) must be tested once per interval, at or near the Enclosure to PLA-8113 Page 2 of 3

end of the interval. As shown in Reference 1, Table 5.1, Susquehanna did test the subject piping between the IB and OB MSIV of the D MSL multiple times during the fourth 10-year Inservice Inspection interval, most recently in April 2020. However, none of these tests are considered at or near the end of the interval. Therefore, Susquehanna is requesting to take exception to the at or near the end of the interval scheduling requirement of ASME Code,Section XI, IWB-5222(b) and Table IWB-2500 -1 for the subject piping between the IB and OB MSIV of the D MSL.

RAI-2

Section 5 of [Reference 1], states:

... the proposed alternative is to perform a partial IWB-5222(b) pressure boundary test during the 2024 RIO, including all piping applicable to the IWB-5222(b) pressure boundary and the Main Steam system MSL D to the IB MSIV, subsequently test the remainder of the boundary (all piping applicable to the IWB-5222(a) pressure boundary and the Main Steam system MSL D to the OB MSIV) during the next Unit 1 RIO (projected for spring 2026).

Confirm that the above means the following:

The IWB-5222(b) pressure boundary inspection performed during the 2024 RIO will include all required piping systems, including the Main Steam System, except for Main Steam system MSL D IB [MSIV] to OB [MSIV]. The Main Steam system MSL D IB [MSIV] to OB [MSIV]

will be deferred this RIO and be performed during the next RIO (projected for spring 2026) during the IWB-5222(a) pressure boundary inspection. Hence, all the inspections required under IWB-5222 will be completed at least once during the 2024 and/or 2026 RIO.

Susquehanna Response

Yes, Susquehanna concurs that the provided statement aligns with the intent of Reference 1, Section 5.

RAI-3

[Reference 1] states that when these tests are considered in the aggregate, the entire Class 1 pressure boundary is shown to be pressure tested to requirements of IWB-5222(b) within the fourth 10-year ISI interval. The NRC staff notes that the alternative is only asking an exception to the requirement that the testing was not performed at or near the end of the interval (2014-2024). Testing was performed during this interval in 2016, 2018 and 2020, but the timing of these inspections was not at the end of the interval (2024). To meet the intent of the ASME Code of ensuring the inspection interval does not exceed 10 years, the alternative is proposing to Enclosure to PLA-8113 Page 3 of 3

perform the deferred inspection in 2026, thereby making the time between inspections less than 10 years. Based on the understanding above, confirm whether the licensee would conclude that the information provided in the proposed alternative, including the previous inspections performed, would justify that the proposed alternative provides for an acceptable level of quality and safety as set forth in 10 CFR 50.55a(z)(1).

Susquehanna Response

Yes, Susquehanna agrees that the information provided in Reference 1 would justify that the proposed alternative provides for an acceptable level of quality and safety as set forth in 10 CFR 50.55a(z)(1).

Note, Susquehanna continues to request authorization of the proposed alternative by April 12, 2024.

References

1. Susquehanna letter to NRC, Relief Request 4RR-11 Relief Request from End of Interval Boundary Leakage Test (PLA-8112), dated April 09, 2024 (ADAMS Accession No. ML24100A832).

2. NRC email to Susquehanna, Request for Additional Information for Susquehanna Unit 1 Alternative Request 4RR-11, dated April 10, 2024.