IR 05000259/2025002

Integrated Inspection Report 05000259/2025002; 05000260/2025002, 050000296/2025002, and 07200052/2025001

ML25210A511
Person / Time
Site:	Browns Ferry
Issue date:	08/06/2025
From:	Renee Taylor NRC/RGN-II/DORS/PB5
To:	Erb D Tennessee Valley Authority
References
IR 2025001, IR 2025002
Download: ML25210A511 (1)

Text

SUBJECT:

BROWNS FERRY NUCLEAR PLANT - INTEGRATED INSPECTION REPORT 05000259/2025002, 05000260/2025002, 05000296/2025002, AND 07200052/2025001

Dear Delson Erb:

On June 30, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Browns Ferry Nuclear Plant. On July 15, 2025, the NRC inspectors discussed the results of this inspection with Mr. David Renn, Site Regulatory Compliance Manager, and other members of your staff. The results of this inspection are documented in the enclosed report.

No findings or violations of more than minor significance were identified during this inspection.

This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Ryan C. Taylor, Chief Projects Branch 5 Division of Operating Reactor Safety Docket Nos. 05000259, 05000260, 05000296, 07200052 License Nos. DPR-33, DPR-52, and DPR-68

Enclosure:

As stated

Inspection Report

Docket Numbers:

05000259, 05000260, 05000296, and 07200052

License Numbers:

DPR-33, DPR-52, and DPR-68

Report Numbers:

05000259/2025002, 05000260/2025002, 05000296/2025002, and

07200052/2025001

Enterprise Identifier:

I-2025-002-0019 and I-2025-001-0088

Licensee:

Tennessee Valley Authority

Facility:

Browns Ferry Nuclear Plant

Location:

Athens, Alabama

Inspection Dates:

April 1, 2025, to June 30, 2025

Inspectors:

S. Billups, Resident Inspector

P. Cooper, Senior Reactor Inspector

J. Copeland, Reactor Inspector

W. Deschaine, Senior Project Engineer

M. Hagen, Reactor Inspector

K. Lei, Emergency Preparedness Inspector

K. Pfeil, Senior Resident Inspector

A. Ponko, Senior Construction Project Inspector

T. Steadham, Executive Technical Assistant

J. Vasquez, Construction Project Inspector

J. Walker, Senior Emergency Preparedness Inspector

Approved By:

Ryan C. Taylor, Chief

Projects Branch 5

Division of Operating Reactor Safety

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Browns Ferry Nuclear Plant, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

No findings or violations of more than minor significance were identified.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000296/2025-001-00 Unit 3, Automatic Reactor Scram Following Main Generator Trip 71153 Closed LER 05000296/2025-001-01 Unit 3, Automatic Reactor Scram Following Main Generator Trip 71153 Closed

PLANT STATUS

Unit 1 began the inspection period at full (100 percent) rated thermal power (RTP). On May 19, 2025, operators manually shut down the unit for forced outage F113 to make repairs on the main generator bus bar. Following completion of the repairs, operators restarted the unit on May 22, 2025. On May 29, 2025, the unit was returned to full RTP where it remained at or near for the remainder of the inspection period.

Unit 2 began the inspection period in mode 4 in support of planned refueling outage 2R23. On April 10, 2025, operators restarted the unit following completion of outage work. On April 20, 2025, the unit was returned to 100 percent RTP. On May 9, 2025, operators lowered reactor power to 62 percent RTP for a control rod sequence exchange. On May 10, 2025, the unit was returned to 100 percent RTP. On May 12, 2025, a manual scram occurred due to a loss of electro-hydraulic control pressure, resulting in forced outage F209. Following repairs, operators restarted the unit on May 16, 2025. On May 19, 2025, the unit was returned to full RTP. On May 30, 2025, the licensee performed a rapid down power to 39 percent RTP due to a 2A reactor recirculation pump trip, followed by a manual scram due to a subsequent trip of the 2B reactor recirculation pump, starting forced outage F210. On June 5, 2025, following repairs, the unit was restarted and returned to full RTP on June 8, 2025, where it remained at or near for the remainder of the inspection period.

Unit 3 began the inspection period at full RTP. On May 31, 2025, operators lowered reactor power to 68 percent RTP for a control rod sequence exchange. On June 1, 2025, the unit was returned to 100 percent RTP where it operated at or near for the remainder of the inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed onsite portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (3 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) Unit 2 reactor building superstructure main steam valve vault to turbine building steam tunnel blowout panels on April 10, 2025

(2) Unit 2 high pressure coolant injection following system maintenance on April 25, 2025

(3) Unit 3 control bay chiller 3B after permanent modifications on May 12, 2025

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Unit 2, fire area 26, turbine building moisture separator room and steam tunnel elevation 586' on April 4, 2025

(2) Unit 3, fire area 3-4, standby liquid control system areas, elevation 621' and 639' on April 23, 2025

(3) Unit 1, fire area 26, reactor building main steam valve vault, elevation 565' on May 21, 2025

(4) Unit common, FLEX equipment storage building on June 16, 2025

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections for the Unit 2 reactor building steam vault drainage system on April 11, 2025.

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) Unit 2 residual heat removal heat exchanger 2A inspection under work order (WO)

===124517746 on June 13, 2025

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (2 Samples)

(1) The inspectors observed and evaluated licensed operator performance in the control room during Unit 2 startup from refueling outage 2R23 on April 10, 2025.

(2) The inspectors observed and evaluated licensed operator performance in the main control room during Unit 1 outage shutdown and scram recovery on May 20, 2025.

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01)===

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1)maintenance risk assessment during unit common 4 kV shutdown bus 1 planned outage on May 8, 2025 (2)maintenance risk assessment during Unit 2 residual heat removal system loop 1 planned outage on May 28, 2025

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1)condition report (CR) 1997451, Unit 2 high pressure coolant injection room temperature switch as-found out of tolerance on April 10, 2025

(2) CR 2001054, jet pump restraint assembly bracket indications on April 11, 2025

(3) CR 2005579, Unit 1 core spray pump 1A main control room indications on April 15, 2025

(4) CR 1997586, Unit 3 standby diesel generator 3B air start check valve binding on April 30, 2025

(5) CR 2009257, Unit 2 reactor core isolation cooling rupture disk high pressure relay improperly energized on May 29, 2025

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (2 Samples)

The inspectors evaluated the following temporary or permanent modifications:

(1) Unit 2 main steam valve vault long term scaffold evaluation on April 9, 2025

(2) Unit 3 3B control bay chiller analog to digital control system modifications on May 9, 2025

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated the following:

(1) Unit 2 refueling outage 2R23 activities (April 1, 2025, through April 15, 2025)

(2) Unit 2 forced outage activities (May 12, 2025, through May 17, 2025)

(3) Unit 1 forced outage activities (May 19, 2025, through May 22, 2025)

(4) Unit 2 forced outage activities (May 30, 2025, through June 6, 2025)

71111.24 - Testing and Maintenance of Equipment Important to Risk

The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:

Post-Maintenance Testing (PMT) (IP Section 03.01) (8 Samples)

(1) WO 124425462, Unit 2 main steam relief valves solenoid test after solenoid replacement on April 1, 2025

(2) WO 123809932, Unit 2 reactor core isolation cooling system rated flow at low reactor pressure vessel pressure (150 psi) test following maintenance during refueling outage on April 7, 2025

(3) WO 123797044, Unit 2 primary containment as-left leakage rate following refueling outage maintenance on April 11, 2025

(4) WO 125020450, Unit 2 high pressure coolant injection comprehensive pump test following maintenance during refueling outage on April 16, 2025

(5) WO 123809756, Unit 2 ASME section XI system leakage test of the reactor pressure vessel and associated piping following refueling outage maintenance on April 21, 2025

(6) WO 125039194, Unit 2 main bus cooling fan motor 2B replacement on April 22, 2025

(7) WO 125181124, Unit 1 primary containment local leak rate test of the torus hatch penetration X-200A on April 23, 2025

(8) WO 124248598, Unit 3 control bay chiller 3B testing following installation of new control panel and modification of internal wiring on May 12, 2025

Surveillance Testing (IP Section 03.01) (2 Samples)

(1) WO 124346446, Unit 3 standby liquid control 3A and 3B pumps performance test on April 23, 2025

(2) WO 124346450, Unit 3 core spray flow rate test loop II on April 28, 2025

Diverse and Flexible Coping Strategies (FLEX) Testing (IP Section 03.02) (1 Sample)

(1) WO 124579298 and 124569185, 4 kV combustion turbine generator testing for FLEX support on June 18, 2025

71114.01 - Exercise Evaluation

Inspection Review (IP Section 02.01-02.11) (1 Sample)

(1) The inspectors evaluated the biennial emergency plan exercise during the week of June 23, 2025. The scenario began with a simulated Unit 2 RCS leak which initiates from the bottom head into the drywell. Drywell pressure rises to greater than emergency action level threshold due to the reactor pressure vessel leakage, and an Alert is declared. A short time after, Unit 2s main steam line breaks inside the drywell. The break causes a rapid spike in drywell pressure. After about five minutes, the increased drywell pressure causes a failure of the drywell head gasket and a rapid depressurization occurs, which met the conditions for declaration of a Site Area Emergency. Fuel conditions degrade, increasing radiation levels. When radiation levels reached the prescribed threshold, conditions for a General Emergency were met, and the Offsite Response Organizations were able to demonstrate their ability to implement emergency actions.

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Section 02.01-02.03) (1 Sample)

(1) The inspectors evaluated submitted Emergency Action Level, Emergency Plan, and Emergency Plan Implementing Procedure changes during the week of June 23, 2025. This evaluation does not constitute NRC approval.

71114.06 - Drill Evaluation

Additional Drill and/or Training Evolution (1 Sample)

(1) The inspectors observed and evaluated an emergency preparedness drill on April 30, 2025. Events included loss of water level in the spent fuel pool above irradiated fuel, rise in area radiation levels, 2A and 2B recirculation pump failure and trip, an anticipated transient without scram, and a high pressure coolant injection pump leak outside of drywell after isolation valves failed to isolate.

71114.08 - Exercise Evaluation - Scenario Review

Inspection Review (IP Section 02.01 - 02.04) (1 Sample)

(1) The inspectors reviewed and evaluated in-office, the proposed scenario for the biennial emergency plan exercise at least 30 days prior to the day of the exercise.

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

MS05: Safety System Functional Failures Sample (IP Section 02.04)===

(1) Unit 1 (April 1, 2024, through March 31, 2025)

(2) Unit 2 (April 1, 2024, through March 31, 2025)

(3) Unit 3 (April 1, 2024, through March 31, 2025)

MS07: High Pressure Injection Systems (IP Section 02.06) (3 Samples)

(1) Unit 1 (April 1, 2024, through March 31, 2025)

(2) Unit 2 (April 1, 2024, through March 31, 2025)

(3) Unit 3 (April 1, 2024, through March 31, 2025)

MS08: Heat Removal Systems (IP Section 02.07) (3 Samples)

(1) Unit 1 (April 1, 2024, through March 31, 2025)

(2) Unit 2 (April 1, 2024, through March 31, 2025)

(3) Unit 3 (April 1, 2024, through March 31, 2025)

EP01: Drill/Exercise Performance Sample (IP Section 02.12) (1 Sample)

(1) January 1, 2024, through March 31, 2025 EP02: Emergency Response Organization Drill Participation (IP Section 02.13) (1 Sample)

(1) January 1, 2024, through March 31, 2025 EP04: Emergency Response Facility and Equipment Readiness (ERFER) (IP Section 02.14) (1 Partial)

(1)

(Partial)

This is a new NRC performance indicator, described in NEI 99-02, Revision 8 (ML24331A114). Licensees began collecting data for this performance indicator on January 1, 2025. Therefore, at the time of inspection there was no quarterly data compiled and submitted to the NRC.

===71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03) (1 Partial)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

(1)

(Partial)

CR 2007162, corrective actions to address repetitive failures of the 3B diesel right bank starting air check valve 71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)===

(1) The inspectors reviewed the licensees corrective action program to identify potential trends in equipment performance that might be indicative of a more significant safety issue.

71153 - Follow Up of Events and Notices of Enforcement Discretion Event Follow up (IP Section 03.01)

(1) The inspectors evaluated operators' response and event follow-up to a Unit 2 unplanned reactor scram due to turbine trip caused by low electro-hydraulic control pressure on May 12, 2025.

(2) The inspectors evaluated operators' response and event follow-up to a Unit 2 unplanned reactor scram due to trips of both reactor recirculation pumps on May 30, 2025.

Event Report (IP Section 03.02) (1 Sample)

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 05000296/2025-001-00 and LER 05000296/2025-001-01, Unit 3, Automatic Reactor Scram Following Main Generator Trip (ADAMS Accession No.

ML25099A030 and ML25149A021). No performance deficiency nor violation of NRC requirements was identified. These LER's are Closed. Per IMC 0309, Reactive Inspection Decision Basis for Power Reactors, the NRC considered whether the event described in these LERs should be the subject of a reactive inspection and determined that a reactive inspection was not necessary as documented in ML25057A286.

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

===60859 - Independent Spent Fuel Storage Installation License Renewal Inspection Inspections were conducted using the appropriate portions of the IPs in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2690, Inspection Program for Storage of Spent Reactor Fuel and Reactor-Related Greater-than-Class C Waste at Independent Spent Fuel Storage Installations (ISFSI) and for 10 CFR Part 71 Transportation Packaging.

Independent Spent Fuel Storage Installation License Renewal Inspection===

(1) The inspectors reviewed a sample of documents planning and implementing aging management activities (i.e., time-limited aging analyses (TLAA) and aging management programs (AMPs)) required by renewed Certificates of Compliance (CoC) 1014-1 and 1014-5 issued for the HI-STORM 100 cask system and described in the applicable Final Safety Analysis Reports (FSARs).

The inspection team was onsite from June 9-12, 2025. During this time, the inspectors reviewed implementing documents, observed in-process activities, and conducted interviews with licensee staff to verify that the licensee had planned and was implementing the necessary actions to:

(a) comply with the conditions stipulated in the renewed CoCs; and

(b) implement the TLAAs and AMPs as described in updated HI-STORM 100 FSARs and associated NRC safety evaluation report.

The inspectors reviewed NPG-SPP-07.9.5, Dry Cask Storage Aging Management Program for HI-STORM 100 Systems, Revision 0001, which provides programmatic governance and implementation of the Tennessee Valley Authority (TVA) ISFSI AMPs. Additionally, the inspectors directly observed activities associated with the leading cask Multi-Purpose Canister (MPC) AMP and HI-STORM 100 Overpack AMP while onsite. Specifically, the inspectors observed remote visual inspection of MPC

1. 1021-113 and HI-STORM 100 Overpack #1024-142 exterior and interior surfaces, respectively, performed in accordance with MPC-BFN-003, Holtec Vendor Instruction for MPC and HI-STORM Aging Management Examination, Revision 12.

For those license renewal items that were not completed at the time of this inspection, the team verified that there was reasonable assurance that the items were on track for completion in accordance with an established implementation schedule consistent with the conditions of the CoCs, FSARs, technical specifications, and the NRC safety evaluation report.

INSPECTION RESULTS

No findings were identified.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On June 12, 2025, the inspectors presented the ISFSI license renewal inspection results to Mr. Daniel Komm, Site Vice President, and other members of the licensee staff.

• On June 26, 2025, the inspectors presented the emergency preparedness inspection results to Mr. Walter Lee, Nuclear Emergency Preparedness Senior Manager, and other members of the licensee staff.

• On July 15, 2025, the inspectors presented the integrated inspection results to Mr. David Renn, Site Regulatory Compliance Manager, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

BFE-4918

PAR of BFN Dry Cask Aging Management Cask Selection

Revision 0

BFN 10 CFR

2.212

Report of Evaluations for the HI-STORM 100 System

Revision 8

HI-2002444

Holtec International, HI-STORM 100 Final Safety Analysis

Report

Revision 2.1

Miscellaneous

HI-2002444

Holtec International, HI-STORM 100 Final Safety Analysis

Report

Revision 7.1

MPC-BFN-003

Holtec Vendor Instruction for MPC and HI-STORM Aging

Management Examination

Revision 12

Procedures

NPG-SPP-07.9.5

Dry Cask Storage Aging Management Program for HI-

STORM 100 Systems

Revision

0001

60859

Self-Assessments CR Number:

2001242

BFN Independent Spent Fuel Storage (ISFSI) Aging

Management Program (AMP) Effectiveness

Revision 0

71111.07A

Work Orders

24517746

Corrective Action

Documents

CR 1997451,

1997586,

2001054,

2005579,

2009257

0-45E765-26

Wiring Diagram 4160V Shutdown Auxiliary Power Schematic

Diagram

Revision 11

0-730E930-3

Elementary Diagram Core Spray System

Revision 13

1-45E765-7

Wiring Diagram 4160V Shutdown Auxiliary Power Schematic

Diagram

Revision 22

71111.15

Drawings

1-730E929-2

Automatic Blowdown System

Revision 21

Engineering

Evaluations

Long Term Scaffold Request for Scaffold 25-MS-067-2

04/05/2025

BFN 20-1822-02

Unit 3 - B Control Bay Chiller Digital Upgrades

Revision 1

FCR-TVA-2025-

2903

Qualification of New Ferulok Fittings and Addition of Mark

Numbers for Connections C14 and C15

04/07/2025

71111.18

Miscellaneous

FCR-TVA-2025-

2974

Request to re-route 1/4" OD SS sense lines for 3-PT-03-

1951A and 3-PT-1951B

04/25/2025

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

FCR-TVA-2025-

2992

Update Junction Box support for transductor mounting

04/24/2025

FCR-TVA-2025-

2998

Remove extraneous Expansion Solenoid

04/26/2025

FCR-TVA-2025-

2999

Incorporate As-built Dimensions for Chiller 3B Tubing Routes

04/26/2025

Corrective Action

Documents

2000772,

2008508,

2008258

71111.24

Work Orders

24425462,

23638692,

23809932,

23797044,

23809756,

25039194,

24346446,

24346450,

23389290,

24248598,

25181124,

24579298,

24569185,

25020450

EPIP-1

Emergency Classification Procedure

Rev. 68

REP-Appendix A

Browns Ferry Nuclear Plant Radiological Emergency Plan

Rev. 114

71114.01

Procedures

REP-Generic

Radiological Emergency Plan (Generic Part)

Rev. 117

71152A

Corrective Action

Documents

1779634,

1799069,

1813331,

1813643,

1866096,

1884223,

1997586,

2004275,

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

1814485,

1970047

Corrective Action

Documents

Resulting from

Inspection

2007162,

2011280

Work Orders

2102380,

25281021,

23278111,

23626978,

2895304,

2884648,

2884649,

2884666,

2884667,

24467612,

24467613

Corrective Action

Documents

1990732

Miscellaneous

EMI Test Report

PO 7548239

Electromagnetic Interference (EMI) Test Report PO 7548239

71153

Procedures

EPI-0-242-

BUS001

Main Transformer, Unit Station Service Transformer and

Associated Bus Work (Major Outage)

Revision 52