ML25042A041
| ML25042A041 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  (DPR-33, DPR-52, DPR-68) |
| Issue date: | 02/10/2025 |
| From: | Kimberly Green Plant Licensing Branch III |
| To: | Eckermann J Tennessee Valley Authority |
| References | |
| L-2024-LLA-0163 | |
| Download: ML25042A041 (5) | |
Text
From:
Kimberly Green Sent:
Monday, February 10, 2025 1:52 PM To:
Eckermann, Jeremy Beau
Subject:
Request for Additional Information -TVA LAR to Revise Browns Ferry Technical Specification 3.4.3 by Adopting TSTF-576 (EPID L-2024-LLA-0163)
Attachments:
RAI for TSTF-576 LAR.docx Follow Up Flag:
Follow up Flag Status:
Flagged
Dear Beau Eckermann:
By letter dated December 9, 2024 (Agencywide Documents Access and Management System Accession No. ML24344A034), Tennessee Valley Authority (TVA) submitted a license amendment request to the U.S. Nuclear Regulatory Commission (NRC) that requested changes to Browns Ferry Nuclear Plant, Units 1, 2, and 3, Technical Specification (TS) 3.4.3, Safety/Relief Valves (S/RVs), by adopting Technical Specification Task Force (TSTF) Traveler TSTF-576, Revision 3, Revise Safety/Relief Valve Requirements.
The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has identified areas where additional information is needed to complete its review. A draft request for additional information (RAI) was previously sent to you by email dated January 31, 2025.
You indicated that a clarification call was not necessary.
A response to the attached RAI, which is unchanged from the draft RAI, is requested within 30 days of the date of this email. The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please me at (301) 415-1627 or via email at Kimberly.Green@nrc.gov Sincerely, Kimberly Green Senior Project Manager Division of Operating Reactor Licensing U.S. Nuclear Regulatory Commission 301-415-1627
Hearing Identifier:
NRR_DRMA Email Number:
2722 Mail Envelope Properties (SA1PR09MB916371B756794E2D4FF6D8B58FF22)
Subject:
Request for Additional Information -TVA LAR to Revise Browns Ferry Technical Specification 3.4.3 by Adopting TSTF-576 (EPID L-2024-LLA-0163)
Sent Date:
2/10/2025 1:52:12 PM Received Date:
2/10/2025 1:52:00 PM From:
Kimberly Green Created By:
Kimberly.Green@nrc.gov Recipients:
"Eckermann, Jeremy Beau" <jbeckermann@tva.gov>
Tracking Status: None Post Office:
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REQUEST FOR ADDITIONAL INFORMATION TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, 50-296 Introduction By letter dated December 9, 2024 (Agencywide Documents Access and Management System Accession No. ML24344A034), the Tennessee Valley Authority (TVA) submitted a license amendment request (LAR) for the Browns Ferry Nuclear Plant, Units 1, 2, and 3 (Browns Ferry or BFN). Specifically, the proposed amendments would revise Browns Ferry Technical Specification (TS) 3.4.3, Safety/Relief Valves (S/RVs), by adopting Technical Specification Task Force (TSTF) Traveler TSTF-576, Revision 3, Revise Safety/Relief Valve Requirements.
The U.S. Nuclear Regulatory Commission (NRC) is reviewing the LAR, and has identified where additional information is needed to complete its review. The requested information is identified below.
Regulatory Basis The regulation at paragraph 50.36(c)(2)(ii)(C) of Title 10 of the Code of Federal Regulations (10 CFR) requires the establishment of a limiting condition for operation (LCO) for a structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
The regulation at 10 CFR 50.36(c)(3) addresses surveillance requirements (SRs) which are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the LCO will be met.
Requests
RAI-1
The proposed revision to the Browns Ferry, Unit 1, Core Operating Limits Report (COLR),
shown in Attachment 3 to the Enclosure to the LAR (provided for information only), states, in part:
The as-found OPS lift pressures of the required S/RVs are within +/- 3% of the limits specified below:
Number of S/RVs As-Found Lift Pressure Limit (psig) 4 1135 4
1145 5
1155 Traveler TSTF-576 removed the lower tolerance (i.e., the -3%), however, it is included as part of the sample COLR page but is not marked as a variation.
The proposed SR 3.4.3.2 requires that the as-found Overpressure Protection System (OPS) lift pressures of the required S/RVs be within the limits specified in the COLR.
Clarify which pressure limits are intended to be used in SR 3.4.3.2 and provide an updated sample COLR page, as appropriate.
RAI-2
The Applicable Safety Analyses portion of the proposed TS 3.4.3 Bases states that the overpressure analyses assume 12 S/RVs operate in the safety mode of operation. However, the sample COLR page shows that 13 S/RVs are required. The values in the COLR should be consistent with, or more conservative, than what is assumed in the safety analysis.
Clarify how many S/RVs are required to operate in the safety mode and update the Bases or COLR, as appropriate, to resolve this apparent inconsistency.
RAI-3
Traveler TSTF-576, Revision 3, states that plant-specific amendments to adopt the proposed change will add the OPS specification to paragraph a of the COLR TS and notes that this addition should be consistent in format with the existing list of specifications referenced there.
Section 3.1 of the Enclosure to the LAR states [t]he COLR specification is revised to reference the OPS specification; however, there were no proposed changes to TS 5.6.5.a to add the reference to proposed TS 3.4.3, Overpressure Protection System (OPS).
Explain why a proposed change to TS 5.6.5.a is not needed, or propose a revision to TS 5.6.5.a to reflect the reference to TS 3.4.3.
RAI-4
The proposed SR 3.4.3.1 requires the required as-left S/RV settings to be within +/-1% of the nominal setpoint of the valve. The SR lists all 13 installed valves. The applicable TS Bases markup states that 12 valves are required to perform the OPS function.
The NRC staff determined that any S/RV that is not set per SR 3.4.3.1 cannot be credited in the as-found test group (SR 3.4.3.2, based on the COLR valve settings list) because the valve would not be verified to be operable based on the as-left setting.
LCO 3.0.1 requires that the S/RVs credited for the OPS must be operable in all modes and specified conditions of the applicability. The lack of an acceptable as-left test would make the S/RV unable to contribute to OPS operability.
Explain how the operators will ensure that only the S/RVs that are determined to be operable by as-left testing per SR 3.4.3.1 are credited when performing SR 3.4.3.2.
RAI-5
Section 2.2, Optional Changes and Variations, of the LAR states that the LCO section of the Bases 3.4.3 contains a bracketed inclusion of relief mode for overpressure protection and it is applicable as all S/RVs at Browns Ferry are capable of safety and relief mode for overpressure protection.
This appears to be contradictory to the proposed revision for the Background section of TS Bases 3.4.3, which states that The safety mode is credited for overpressure protection, and S/RVs operating in relief mode are not credited for overpressure protection.
Additionally, the proposed revision for the LCO section of TS Bases 3.4.3 (bottom of Bases page B 3.4-18) states:
The OPS is OPERABLE when it can ensure that the ASME Code limit on peak reactor pressure, as stated in Safety Limit 2.1.2, will be protected using the safety and relief modes [emphasis added] of the S/RVs. The OPERABILITY of the OPS is only dependent on the ability to relieve excess pressure and maintain reactor pressure below Safety Limit 2.1.2, and may credit less than the full complement of installed S/RVs.
Explain these apparent contradictions regarding the safety mode of the OPS, or propose appropriate revisions to the TS Bases and/or variations to Traveler TSTF-576, Revision 3.