CNL-25-063, Response to Request for Additional Information, Set 4
| ML25114A206 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 04/24/2025 |
| From: | Hulvey K Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| CNL-25-063, EPID L-2024-SLE-0000 | |
| Download: ML25114A206 (1) | |
Text
10 CFR 54 1101 Market Street, Chattanooga, Tennessee 37402 CNL-25-063 April 24, 2025 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001
Subject:
Browns Ferry Nuclear Plant, Units 1, 2, and 3 Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 NRC Docket Nos. 50-259, 50-260, and 50-296 Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Response to Request for Additional Information, Set #4 (EPID L-2024-SLE-0000)
Reference:
- 1. TVA letter to NRC, CNL-24-001, "Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Application for Subsequent Renewed Operating Licenses," dated January 19, 2024 (ML24019A010) 2.
TVA letter to NRC, CNL-24-077, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Application for Subsequent Renewed Operating Licenses, Response to Request for Additional Information, Set #1 (EPID L-2024-SLE-0000), dated October 9, 2024 (ML24283A091) 3.
TVA letter to NRC, CNL-25-014, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Response to Request for Additional Information, Set #2 (EPID L-2024-SLE-0000), dated January 8, 2025 (ML25008A150) 4.
TVA letter to NRC, CNL-25-054, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Response to Request for Additional Information, Set #3 (EPID L-2024-SLE-0000), dated March 28, 2025 (ML25087A216) 5.
NRC electronic mail to TVA, Browns Ferry SLRA - Request for Additional Information - Set #4, dated March 25, 2025 (ML25084A197 and ML25085A145)
By Reference 1, the Tennessee Valley Authority (TVA) submitted a subsequent license renewal application (SLRA) for the Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3, Renewed Facility Operating Licenses in accordance with Title 10 of the Code of Federal
U.S. Nuclear Regulatory Commission CNL-25-063 Page 2 April 2, 2025 Regulations (10 CFR), Part 54, Requirements for Renewal of Operating Licenses for Nuclear Power Plants. By Reference 2, TVA provided the response to the first set of Nuclear Regulatory Commission (NRC) requests for additional information (RAIs) regarding the BFN SLRA. By Reference 3, TVA provided the response the NRCs second set of RAIs.
By Reference 4, TVA provided the response to the third set of RAIs. By Reference 5, TVA received a fourth set of NRC RAIs. The TVA RAI response is provided in the enclosure to this letter.
SLRA Commitment 33 is revised as described in the changes to Table A.5 provided in the enclosure. Should you have any questions regarding this submittal, please contact Peter J.
Donahue, Director, Subsequent License Renewal, at pjdonahue@tva.gov.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 2WK day of April 2025.
Respectfully, Kimberly D. Hulvey General Manager, Nuclear Regulatory Affairs and Emergency Preparedness
Enclosure:
Response to Request for Additional Information by the Office of Nuclear Reactor Regulation, Set #4 cc:
NRC Regional Administrator - Region II NRC Branch Chief - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager, License Renewal Projects Branch (Safety)
State Health Officer, Alabama Department of Public Health (w/o Enclosure)
Digitally signed by Edmondson, Carla Date: 2025.04.24 13:01:34
-04'00'
Enclosure CNL-25-063 E-1 of 5 Response to Request for Additional Information by the Office of Nuclear Reactor Regulation, Set #4 The NRC Request for Additional Information (RAI) is provided in italicized font. The Tennessee Valley Authority (TVA) response is provided in unitalicized font.
Regulatory Basis Title 10 of the Code of Federal Regulations Section 54.21(a)(3) requires the applicant to demonstrate that the effects of aging for structures and components will be adequately managed so that the intended function will be maintained consistent with the current licensing basis (CLB) for the period of extended operation. As described in the SRP-SLR, an applicant may demonstrate compliance with 10 CFR 54.21(a)(3) by referencing the GALL-SLR Report when evaluation of the matter in the GALL-SLR Report applies to the plant.
RAI-ESEB-B.2.1.33-1
Background:
SLRA Supplement 4 (ML25043A035) on PDF Pages 241 and 248 provides Enhancements 5 and 20 to the Structures Monitoring program, which identified the following four aging effects and mechanisms for steel components:
Cracking due to chemical reaction, weathering, settlement, or corrosion of reinforcement
Loss of material due to corrosion, delamination, exfoliation, spalling, popout, or scaling
Loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear
Loss of preload due to self-loosening The staff reviewed the GALL-SLR report and finds that the first two bulleted aging effects and mechanisms above are applicable to concrete components (e.g., NUREG-2191 Item VII.G.A-90), not for steel components.
Issue:
Enhancements 5 and 20 to the Structures Monitoring program in SLRA Supplement 4 do not make clear the types of steel components, associated aging effects/mechanisms, and Table 2 AMR items for steel components.
Request:
1.
Clarify the types of steel components addressed by Enhancements 5 and 20 to the Structures Monitoring program in SLRA Supplement 4.
2.
Evaluate the applicability of the first two aging effects and mechanisms above for steel components and provide justification as needed.
3.
Clarify or provide Table 2 AMR items for the identified steel components and associated aging effects/mechanisms.
Enclosure CNL-25-063 E-2 of 5 TVA Response
- 1.
The steel components addressed by Enhancements 5 and 20 are for combustible liquid retention fire barriers, such as steel oil-containment-barriers.
- 2.
The aging effects/mechanisms are applicable to concrete components rather than that of steel as reflected in NUREG-2191 Volume 1 for VII.G.A-90.
- 3.
From a review of NUREG-2191 Volume 1 and BFN design input documents, revisions are made to SLRA pages 3-344, 3-922, A-48, A-49, A-126, A-128, B-168, and B-169 for the following.
Alignment of environment with NUREG-2191 Volume 1 for VII.G.A-90 crediting reinforced concrete components for SLRA Tables 3.3.1 and 3.5.2-36.
Revision to the noted steel component line items to credit an aging effect/mechanism applicable to the material/environment combination for SLRA Table 3.5.2-36.
Revision to the Structures Monitoring Program to remove the noted aging effects from Enhancements 5 and 20. This addresses the requested additional GALL-SLR Report AMR Table 2 information. The final verbiage for these changes is as compared with the original SLRA, Revision 0, and therefore incorporates previously submitted changes, as applicable.
SLRA Table 3.3.1 on Page 3-344 is revised as follows:
3.3-1, 060 Reinforced concrete structural fire barriers: walls, ceilings and floors exposed to air Cracking due to chemical reaction, weathering, settlement, or corrosion of reinforcement; loss of material due to delamination, exfoliation, spalling, popout, or scaling AMP XI.M26, Fire Protection, and AMP XI.S6, Structures Monitoring No Consistent with NUREG-2191. The Fire Protection program (B.2.1.15) and Structures Monitoring program (B.2.1.33) will be used to manage cracking and loss of material of the concrete and grout fire barriers and concrete elements exposed to airindoor uncontrolled and air-outdoor as shown in Table 3.5.2-36 of Structural Commodities (Hazard Barriers and Elastomers).
SLRA Table 3.5.2-36 on Page 3-922 is revised as follows:
Structural Fire Barriers:
- walls, ceilings and floors Fire Barrier Reinforced Concrete Air - indoor uncontrolled Air Cracking due to chemical reaction, weathering, settlement, or corrosion of reinforcement; loss of material due to delamination, exfoliation, spalling, popout, or scaling Fire Protection (B.2.1.15) and Structures Monitoring (B.2.1.33)
VII.G.A-90 3.3-1, 060 A,
16 Structural Fire Barriers:
- walls, ceilings and floors Fire Barrier Reinforced Concrete Air - outdoor Cracking due to chemical reaction, weathering, settlement, or corrosion of reinforcement; loss of material due to delamination, exfoliation, spalling, Fire Protection (B.2.1.15) and Structures Monitoring (B.2.1.33)
VII.G.A-90 3.3-1, 060 A,
16
Enclosure CNL-25-063 E-3 of 5 popout, or scaling Structural Fire Barriers:
- walls, ceilings and floors Fire Barrier Steel Air - indoor uncontrolled Air Cracking due to chemical reaction, weathering, settlement, or corrosion of reinforcement; loss of material due to delamination, exfoliation, spalling, popout, or scaling Loss of material due to corrosion Fire Protection (B.2.1.15) and Structures Monitoring (B.2.1.33)
VII.G.A-90 None 3.3-1, 060None FJ, 16 Structural Fire Barriers:
- walls, ceilings and floors Fire Barrier Steel Air - outdoor Cracking due to chemical reaction, weathering, settlement, or corrosion of reinforcement; loss of material due to delamination, exfoliation, spalling, popout, or scaling Fire Protection (B.2.1.15) and Structures Monitoring (B.2.1.33)
VII.G.A-90 3.3-1, 060 F,
16 SLRA Appendix A on Page A-48 is revised as follows:
5.
Revise implementing procedures to ensure steel, aluminum, and non-ferrous material components are monitored for cracking, loss of material due to corrosion or mechanical wear, and general degradation. the aging effects for aluminum, non-ferrous copper alloys, stainless steel, and steel components are monitored for each material type:
Aluminum components are monitored for (1) loss of preload due to self-loosening.
Non-ferrous copper alloy components are monitored for (1) loss of material due to mechanical wear.
Stainless steel components are monitored for (1) loss of material due to corrosion or mechanical wear; and (2) loss of preload due to self-loosening.
Steel components are monitored for (1) loss of material due to corrosion; (2) loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear; and (3) loss of preload due to self-loosening.
SLRA Appendix A on Page A-49 is revised as follows:
20.
Revise implementing procedures to ensure no significant cracking, no significant loss of material due to corrosion or mechanical wear, and no significant signs of general degradation for steel, aluminum, and non-ferrous material components. there are no degradations to in-scope aluminum, non-ferrous copper alloys, stainless steel, and steel components that would prevent the components from completing their intended design function:
Aluminum components are managed for (1) loss of preload due to self-loosening.
Non-ferrous copper alloy components are managed for (1) loss of material due to mechanical wear.
Stainless steel components are managed for (1) loss of material due to corrosion or mechanical wear; and (2) loss of preload due to self-loosening.
Enclosure CNL-25-063 E-4 of 5
Steel components are managed for (1) loss of material due to corrosion; (2) loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear; and (3) loss of preload due to self-loosening.
SLRA Table A.5 on Page A-126 for Commitment 33 is revised as follows:
5.
Revise implementing procedures to ensure steel aluminum, and non-ferrous material components are monitored for cracking, loss of material due to corrosion or mechanical wear, and general degradation. the aging effects for aluminum, non-ferrous copper alloys, stainless steel, and steel components are monitored for each material type:
Aluminum components are monitored for (1) loss of preload due to self-loosening.
Non-ferrous copper alloy components are monitored for (1) loss of material due to mechanical wear.
Stainless steel components are monitored for (1) loss of material due to corrosion or mechanical wear; and (2) loss of preload due to self-loosening.
Steel components are monitored for (1) loss of material due to corrosion; (2) loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear; and (3) loss of preload due to self-loosening.
SLRA Table A.5 on Page A-128 for Commitment 33 is revised as follows.
20.
Revise implementing procedures to ensure no significant cracking, no significant loss of material due to corrosion or mechanical wear, and no significant signs of general degradation for steel, aluminum, and non-ferrous material components. there are no degradations to in-scope aluminum, non-ferrous copper alloys, stainless steel, and steel components that would prevent the components from completing their intended design function.
Aluminum components are managed for (1) loss of preload due to self-loosening.
Non-ferrous copper alloy components are managed for (1) loss of material due to mechanical wear.
Stainless steel components are managed for (1) loss of material due to corrosion or mechanical wear; and (2) loss of preload due to self-loosening.
Steel components are managed for (1) loss of material due to corrosion; (2) loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear; and (3) loss of preload due to self-loosening.
SLRA Appendix B on Page B-168 is revised as follows:
5.
Revise implementing procedures to ensure steel aluminum, and non-ferrous material components are monitored for cracking, loss of material due to corrosion or mechanical wear, and general degradation. the aging effects for aluminum, non-ferrous copper alloys, stainless steel, and steel components are monitored for each material type:
Aluminum components are monitored for (1) loss of preload due to self-loosening.
Non-ferrous copper alloy components are monitored for (1) loss of material due to mechanical wear.
Enclosure CNL-25-063 E-5 of 5 Stainless steel components are monitored for (1) loss of material due to corrosion or mechanical wear; and (2) loss of preload due to self-loosening.
Steel components are monitored for (1) loss of material due to corrosion; (2) loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear; and (3) loss of preload due to self-loosening.
Program Element Affected: Element 3 - Parameters Monitored or Inspected SLRA Appendix B on Page B-169 is revised as follows:
- 20.
Revise implementing procedures to ensure no significant cracking, no significant loss of material due to corrosion or mechanical wear, and no significant signs of general degradation for steel, aluminum, and non-ferrous material components. there are no degradations to in-scope aluminum, non-ferrous copper alloys, stainless steel, and steel components that would prevent the components from completing their intended design function:
Aluminum components are managed for (1) loss of preload due to self-loosening.
Non-ferrous copper alloy components are managed for (1) loss of material due to mechanical wear.
Stainless steel components are managed for (1) loss of material due to corrosion or mechanical wear; and (2) loss of preload due to self-loosening.
Steel components are managed for (1) loss of material due to corrosion; (2) loss of mechanical function due to corrosion, distortion, dirt or debris accumulation, overload wear; and (3) loss of preload due to self-loosening.
Program Element Affected: Element 6 - Acceptance Criteria