Text

Issuance of Amendment Nos. 337, 360, and 320 Regarding Adoption of TSTF-423-A, Revision 1, Technical Specifications End States, NEDC-32988-A
	ML25337A128
Person / Time
Site:	Browns Ferry
Issue date:	12/18/2025
From:	Kimberly Green; NRC/NRR/DORL/LPL2-2
To:	Erb D; Tennessee Valley Authority
	Green K, NRR/DORL/LPL2-2
References
	EPID L-2025-LLA-0070
	Download: ML25337A128 (0)
	v • d • e

December 18, 2025 Mr. Delson C. Erb Vice President, OPS Support Tennessee Valley Authority 1101 Market Street, LP 4A-C Chattanooga, TN 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 ISSUANCE OF AMENDMENT NOS. 337, 360, AND 320 REGARDING ADOPTION OF TSTF-423-A, REVISION 1, TECHNICAL SPECIFICATIONS END STATES, NEDC-32988-A (EPID L-2025-LLA-0070)

Dear Mr. Erb:

The U.S. Nuclear Regulatory Commission (the Commission) has issued the enclosed Amendment Nos. 337, 360, and 320 to Subsequent Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 for the Browns Ferry Nuclear Plant, Units 1, 2, and 3, respectively. These amendments are in response to your application dated April 10, 2025, as supplemented by letter July 14, 2025.

The amendments revise the Browns Ferry Nuclear Plant, Units 1, 2, and 3, technical specifications by adopting Technical Specification Task Force (TSTF) Traveler TSTF-423-A, Revision 1, Technical Specifications End States, NEDC-32998-A, to modify the end state for selected Required Actions to allow the units to stay in Mode 3.

A copy of our related safety evaluation is also enclosed. A notice of issuance will be included in the Commissions monthly Federal Register notice.

Sincerely,

/RA/

Kimberly J. Green, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296

Enclosures:

1. Amendment No. 337 to DPR-33

2. Amendment No. 360 to DPR-52

3. Amendment No. 320 to DPR-68

4. Safety Evaluation cc: Listserv

TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-259 BROWNS FERRY NUCLEAR PLANT, UNIT 1 AMENDMENT TO SUBSEQUENT RENEWED FACILITY OPERATING LICENSE Amendment No. 337 Subsequent Renewed License No. DPR-33

1.

The U.S. Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by the Tennessee Valley Authority (the licensee) dated April 10, 2025, as supplemented by letter dated July 14, 2025, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR) Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Subsequent Renewed Facility Operating License No. DPR-33 is hereby amended, in part, to read as follows:

(2)

Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 337, are hereby incorporated in this subsequent renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of its date of issuance and shall be implemented within 90 days from the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION David Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Date of Issuance: December 18, 2025 DAVID WRONA Digitally signed by DAVID WRONA Date: 2025.12.18 14:05:35 -05'00'

ATTACHMENT TO LICENSE AMENDMENT NO. 337 SUBSEQUENT RENEWED FACILITY OPERATING LICENSE NO. DPR-33 BROWNS FERRY NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-259 Replace the following pages of the Subsequent Renewed Facility Operating License and Appendix A, Technical Specifications (TSs), with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Remove Insert License DPR-33 License DPR-33 Page 3 Page 3 TSs TSs 3.3-75 3.3-75 3.5-1 3.5-1 3.5-3 3.5-3 3.5-12 3.5-12 3.6-20 3.6-20 3.6-22 3.6-22 3.6-31 3.6-31 3.6-32 3.6-32 3.6-34 3.6-34 3.6-44 3.6-44 3.6-51 3.6-51 3.7-4 3.7-4 3.7-6 3.7-6 3.7-9 3.7-9 3.7-13 3.7-13 3.8-6 3.8-6 3.8-23 3.8-23 3.8-37 3.8-37

Subsequent Renewed License No. DPR-33 Amendment No. 337 accordance with the limitations for storage and amounts required for reactor operation, as described in the Final Safety Analysis Report as supplemented and amended; (3)

Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use at any time any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4)

Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use in amounts as required any byproduct, source, or special nuclear material without restriction to chemical or physical form for sample analysis or equipment and instrument calibration or associated with radioactive apparatus or components; (5)

Pursuant to the Act and 10 CFR Parts 30 and 70, to possess but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C.

This subsequent renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I: Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1)

Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 3952 megawatts thermal.

(2)

Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 337, are hereby incorporated in this subsequent renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.

For Surveillance Requirements (SRs) that are new in Amendment 234 to Facility Operating License DPR-33, the first performance is due at the end of the first surveillance interval that begins at implementation of the Amendment 234. For SRs that existed prior to Amendment 234, including SRs with modified acceptance criteria and SRs whose frequency of performance is being extended, the first performance is due at the end of the first surveillance interval that begins on the date the surveillance was last performed prior to implementation of Amendment 234.

(3)

The licensee is authorized to relocate certain requirements included in Appendix A and the former Appendix B to licensee-controlled documents.

RPS Electric Power Monitoring 3.3.8.2 BFN-UNIT 1 3.3-75 Amendment No. 234, 337 3.3 INSTRUMENTATION 3.3.8.2 Reactor Protection System (RPS) Electric Power Monitoring LCO 3.3.8.2 Two RPS electric power monitoring assemblies shall be OPERABLE for each inservice RPS motor generator set or alternate power supply.

APPLICABILITY:

MODES 1, 2, and 3, MODES 4 and 5 with any control rod withdrawn from a core cell containing one or more fuel assemblies.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or both inservice power supplies with one electric power monitoring assembly inoperable.

A.1 Remove associated inservice power supply(s) from service.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B. One or both inservice power supplies with both electric power monitoring assemblies inoperable.

B.1 Remove associated inservice power supply(s) from service.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months C. Required Action and associated Completion Time of Condition A or B not met in MODE 1, 2, or 3.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

ECCS - Operating 3.5.1 BFN-UNIT 1 3.5-1 Amendment No. 234, 240, 249, 311, 328, 337 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS), RPV WATER INVENTORY CONTROL, AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM 3.5.1 ECCS - Operating LCO 3.5.1 Each ECCS injection/spray subsystem and the Automatic Depressurization System (ADS) function of six safety/relief valves shall be OPERABLE.

APPLICABILITY:

MODE 1, MODES 2 and 3, except high pressure coolant injection (HPCI) and ADS valves are not required to be OPERABLE with reactor steam dome pressure 150 psig.

ACTIONS

NOTE--------------------------------------------------

LCO 3.0.4.b is not applicable to HPCI.

CONDITION REQUIRED ACTION COMPLETION TIME A.

One low pressure ECCS injection/spray subsystem inoperable.

OR One low pressure coolant injection (LPCI) pump in both LPCI subsystems inoperable.

A.1 Restore low pressure ECCS injection/spray subsystem(s) to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

ECCS - Operating 3.5.1 BFN-UNIT 1 3.5-3 Amendment No. 234, 240, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME G. Required Action and associated Completion Time of Condition C, D, E, or F not met G.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months H. Two or more ADS valves inoperable.

H.1 Be in MODE 3.

AND H.2 Reduce reactor steam dome pressure to 150 psig.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours I.

Two or more low pressure ECCS injection/spray subsystems inoperable for reasons other than Condition A.

OR HPCI System and one or more ADS valves inoperable.

I.1 Enter LCO 3.0.3.

Immediately

RCIC System 3.5.3 BFN-UNIT 1 3.5-12 Amendment No. 234, 249, 311, 328, 337 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS), RPV WATER INVENTORY CONTROL, AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM 3.5.3 RCIC System LCO 3.5.3 The RCIC System shall be OPERABLE.

APPLICABILITY:

MODE 1, MODES 2 and 3 with reactor steam dome pressure > 150 psig.

ACTIONS

NOTE--------------------------------------------------

LCO 3.0.4.b is not applicable to RCIC.

CONDITION REQUIRED ACTION COMPLETION TIME A.

RCIC System inoperable.

A.1 Verify by administrative means High Pressure Coolant Injection System is OPERABLE.

Immediately AND A.2 Restore RCIC System to OPERABLE status.

14 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Reactor Building-to-Suppression Chamber Vacuum Breakers 3.6.1.5 BFN-UNIT 1 3.6-20 Amendment No. 234, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. One line with one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening.

C.1 Restore the vacuum breaker(s) to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months D. Required Action and associated Completion Time of Condition C not met.

D.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months E. Two lines with one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening.

E.1 Restore all vacuum breakers in one line to OPERABLE status.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months F. Required Action and Associated Completion Time of Condition A, B, or E not met.

F.1 Be in MODE 3.

AND F.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.6 BFN-UNIT 1 3.6-22 Amendment No. 234, 337 3.6 CONTAINMENT SYSTEMS 3.6.1.6 Suppression Chamber-to-Drywell Vacuum Breakers LCO 3.6.1.6 Ten suppression chamber-to-drywell vacuum breakers shall be OPERABLE for opening.

AND Twelve suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required suppression chamber-to-drywell vacuum breaker inoperable for opening.

A.1 Restore one vacuum breaker to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C.

One suppression chamber-to-drywell vacuum breaker not closed.

C.1 Close the open vacuum breaker.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months D.

Required Action and associated Completion Time of Condition C not met.

D.1 Be in MODE 3.

AND D.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

RHR Suppression Pool Cooling 3.6.2.3 BFN-UNIT 1 3.6-31 Amendment No. 234, 241, 328, 337 3.6 CONTAINMENT SYSTEMS 3.6.2.3 Residual Heat Removal (RHR) Suppression Pool Cooling LCO 3.6.2.3 Four RHR suppression pool cooling subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One RHR suppression pool cooling subsystem inoperable.

A.1 Restore the RHR suppression pool cooling subsystem to OPERABLE status.

30 days B.

Two RHR suppression pool cooling subsystems inoperable.

B.1 Restore one RHR suppression pool cooling subsystem to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program C.

Required Action and associated Completion Time of Condition A or B not met.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months D.

Three or more RHR suppression pool cooling subsystems inoperable.

D.1 Restore required RHR suppression pool cooling subsystems to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (continued)

RHR Suppression Pool Cooling 3.6.2.3 BFN-UNIT 1 3.6-32 Amendment No. 234, 241, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and associated Completion Time of Condition D not met.

E.1 Be in MODE 3.

AND E.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

RHR Suppression Pool Spray 3.6.2.4 BFN-UNIT 1 3.6-34 Amendment No. 234, 328, 337 3.6 CONTAINMENT SYSTEMS 3.6.2.4 Residual Heat Removal (RHR) Suppression Pool Spray LCO 3.6.2.4 Four RHR suppression pool spray subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One RHR suppression pool spray subsystem inoperable.

A.1 Restore the RHR suppression pool spray subsystem to OPERABLE status.

30 days B.

Two RHR suppression pool spray subsystems inoperable.

B.1 Restore one RHR suppression pool spray subsystem to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program C. Three or more RHR suppression pool spray subsystems inoperable.

C.1 Restore required RHR suppression pool spray subsystems to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months D. Required Action and associated Completion Time not met.

D.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Secondary Containment 3.6.4.1 BFN-UNIT 1 3.6-44 Amendment No. 234, 251, 311, 337 3.6 CONTAINMENT SYSTEMS 3.6.4.1 Secondary Containment LCO 3.6.4.1 The secondary containment shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Secondary containment inoperable.

A.1 Restore secondary containment to OPERABLE status.

4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

SGT System 3.6.4.3 BFN-UNIT 1 3.6-51 Amendment No. 234, 251, 311, 337 3.6 CONTAINMENT SYSTEMS 3.6.4.3 Standby Gas Treatment (SGT) System LCO 3.6.4.3 Three SGT subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One SGT subsystem inoperable.

A.1 Restore SGT subsystem to OPERABLE status.

7 days B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. Two or three SGT subsystems inoperable.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

RHRSW System 3.7.1 BFN-UNIT 1 3.7-4 Amendment No. 234, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and associated Completion Time of Condition A, B, C, or D not met.

E.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months F. Three or more required RHRSW pumps inoperable.

F.1 Restore one RHRSW pump to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months G. Three or more RHRSW subsystems inoperable.

G.1

NOTE-------------

Enter applicable Conditions and Required Actions of LCO 3.4.7 for RHR shutdown cooling made inoperable by the RHRSW System.

Restore one RHRSW subsystem to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months H. Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

EECW System and UHS 3.7.2 BFN-UNIT 1 3.7-6 Amendment No. 234, 328, 337 3.7 PLANT SYSTEMS 3.7.2 Emergency Equipment Cooling Water (EECW) System and Ultimate Heat Sink (UHS)

LCO 3.7.2 The EECW System with three pumps and UHS shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required EECW pump inoperable.

A.1 Restore the required EECW pump to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. Two or more required EECW pumps inoperable.

OR UHS inoperable.

C.1 Be in MODE 3.

AND C.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

CREV System 3.7.3 BFN-UNIT 1 3.7-9 Amendment 234, 246, 251, 275, 282, 311, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C.

Two CREV subsystems inoperable due to inoperable High Efficiency Particulate Air (HEPA) filter or charcoal adsorbers which do not impact ability of CREV subsystems to meet flowrate requirements specified in the Ventilation Filter Testing Program (VFTP).

C.1 Restore HEPA filter and one charcoal adsorber to OPERABLE status.

7 days D.

One CREV subsystem inoperable due to inoperable charcoal adsorber which does not impact the ability of CREV subsystem to meet flowrate requirements specified in the VFTP.

D.1 Restore charcoal adsorber to OPERABLE status.

14 days E.

Required Action and associated Completion Time of Condition A, B, C, or D not met.

E.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months F.

Two CREV subsystems inoperable for reasons other than Condition B or C.

F.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Control Room AC System 3.7.4 BFN-UNIT 1 3.7-13 Amendment No. 234, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Two Unit 1 and 2 control room AC subsystems inoperable.

B.1 Initiate action to restore one Unit 1 and 2 control room AC subsystem to OPERABLE status.

Immediately AND B.2 Place an alternate method of cooling in operation.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months AND B.3 Restore one control room AC subsystem to OPERABLE status.

7 days C. Required Action and associated Completion Time of Condition A or B not met in MODE 1, 2, or 3.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

AC Sources - Operating 3.8.1 BFN-UNIT 1 3.8-6 Amendment No. 234, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME H. Two or more Unit 1 and 2 DGs inoperable.

H.1 Restore all but one Unit 1 and 2 DG to OPERABLE status.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months I.

Required Action and Associated Completion Time of Condition A, B, C, D, E, F, or H not met.

I.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months J. One or more required offsite circuits and two or more Unit 1 and 2 DGs inoperable.

OR Two required offsite circuits and one or more Unit 1 and 2 DGs inoperable.

OR Two divisions of 480 V load shed logic inoperable.

OR Two divisions of common accident signal logic inoperable.

J.1 Enter LCO 3.0.3.

Immediately (continued)

DC Sources - Operating 3.8.4 BFN-UNIT 1 3.8-23 Amendment No. 234, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and Associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. One or more DG DC electrical power subsystem(s) inoperable.

C.1 Declare associated DG inoperable.

Immediately D. Unit 3 3EB Shutdown Board DC electrical power subsystem inoperable.

D.1 Declare the affected CREV subsystem inoperable.

Immediately

Distribution Systems - Operating 3.8.7 BFN-UNIT 1 3.8-37 Amendment No. 234, 254, 323, 328, 337 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Unit 1 and 2 4.16 kV Shutdown Board A and B inoperable, for reasons other than Condition I.

OR Unit 1 and 2 4.16 kV Shutdown Board C and D inoperable, for reasons other than Condition I.

NOTE----------------

Enter applicable conditions and required actions of Condition B, C, and F when Condition E results in no power source to a required 480 volt board.

E.1 Restore one 4.16 kV Shutdown Board to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months OR In accordance with the Risk Informed Completion Time Program F. One or more required Unit 2 or 3 AC or DC Boards inoperable, for reasons other than Condition I.

F.1 Declare the affected SGT or CREV subsystem inoperable.

Immediately G. Required Action and associated Completion Time of Condition A, B, C, D, E, or I not met.

G.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-260 BROWNS FERRY NUCLEAR PLANT, UNIT 2 AMENDMENT TO SUBSEQUENT RENEWED FACILITY OPERATING LICENSE Amendment No. 360 Subsequent Renewed License No. DPR-52

1.

The U.S. Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Tennessee Valley Authority (the licensee) dated April 10, 2025, as supplemented by letter dated July 14, 2025, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR) Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Subsequent Renewed Facility Operating License No. DPR-52 is hereby amended, in part, to read as follows:

(2)

Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 360, are hereby incorporated in this subsequent renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of its date of issuance and shall be implemented within 90 days from the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION David Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Date of Issuance: December 18, 2025 DAVID WRONA Digitally signed by DAVID WRONA Date: 2025.12.18 14:06:35 -05'00'

ATTACHMENT TO LICENSE AMENDMENT NO. 360 SUBSEQUENT RENEWED FACILITY OPERATING LICENSE NO. DPR-52 BROWNS FERRY NUCLEAR PLANT, UNIT 2 DOCKET NO. 50-260 Replace the following pages of the Subsequent Renewed Facility Operating License and Appendix A, Technical Specifications (TSs), with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Remove Insert License DPR-52 License DPR-52 Page 3 Page 3 TSs TSs 3.3-76 3.3-76 3.5-1 3.5-1 3.5-3 3.5-3 3.5-12 3.5-12 3.6-20 3.6-20 3.6-22 3.6-22 3.6-31 3.6-31 3.6-32 3.6-32 3.6-34 3.6-34 3.6-44 3.6-44 3.6-51 3.6-51 3.7-4 3.7-4 3.7-7 3.7-7 3.7-10 3.7-10 3.7-14 3.7-14 3.8-6 3.8-6 3.8-23 3.8-23 3.8-37 3.8-37

Subsequent Renewed License No. DPR-52 Amendment No. 360 accordance with the limitations for storage and amounts required for reactor operation, as described in the Final Safety Analysis Report as supplemented and amended; (3)

Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use at any time any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4)

Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use in amounts as required any byproduct, source, or special nuclear material without restriction to chemical or physical form for sample analysis or equipment and instrument calibration or associated with radioactive apparatus or components; (5)

Pursuant to the Act and 10 CFR Parts 30 and 70, to possess but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C.

This subsequent renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I: Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1)

Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 3952 megawatts thermal.

(2)

Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 360, are hereby incorporated in this subsequent renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.

For Surveillance Requirements (SRs) that are new in Amendment 253 to Facility Operating License DPR-52, the first performance is due at the end of the first surveillance interval that begins at implementation of the Amendment 253. For SRs that existed prior to Amendment 253, including SRs with modified acceptance criteria and SRs whose frequency of performance is being extended, the first performance is due at the end of the first surveillance interval that begins on the date the surveillance was last performed prior to implementation of Amendment 253.

(3)

The licensee is authorized to relocate certain requirements included in Appendix A and the former Appendix B to licensee-controlled documents.

RPS Electric Power Monitoring 3.3.8.2 BFN-UNIT 2 3.3-76 Amendment No. 253, 360 3.3 INSTRUMENTATION 3.3.8.2 Reactor Protection System (RPS) Electric Power Monitoring LCO 3.3.8.2 Two RPS electric power monitoring assemblies shall be OPERABLE for each inservice RPS motor generator set or alternate power supply.

APPLICABILITY:

MODES 1, 2, and 3, MODES 4 and 5 with any control rod withdrawn from a core cell containing one or more fuel assemblies.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One or both inservice power supplies with one electric power monitoring assembly inoperable.

A.1 Remove associated inservice power supply(s) from service.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.

One or both inservice power supplies with both electric power monitoring assemblies inoperable.

B.1 Remove associated inservice power supply(s) from service.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months C.

Required Action and associated Completion Time of Condition A or B not met in MODE 1, 2, or 3.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

ECCS - Operating 3.5.1 BFN-UNIT 2 3.5-1 Amendment No. 253, 269, 286, 294, 334, 351, 360 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS), RPV WATER INVENTORY CONTROL, AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM 3.5.1 ECCS - Operating LCO 3.5.1 Each ECCS injection/spray subsystem and the Automatic Depressurization System (ADS) function of six safety/relief valves shall be OPERABLE.

APPLICABILITY:

MODE 1, MODES 2 and 3, except high pressure coolant injection (HPCI) and ADS valves are not required to be OPERABLE with reactor steam dome pressure 150 psig.

ACTIONS

NOTE--------------------------------------------------

LCO 3.0.4.b is not applicable to HPCI.

CONDITION REQUIRED ACTION COMPLETION TIME A.

One low pressure ECCS injection/spray subsystem inoperable.

OR One low pressure coolant injection (LPCI) pump in both LPCI subsystems inoperable.

A.1 Restore low pressure ECCS injection/spray subsystem(s) to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

ECCS - Operating 3.5.1 BFN-UNIT 2 3.5-3 Amendment No. 253, 269, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME G. Required Action and associated Completion Time of Condition C, D, E, or F not met.

G.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months H. Two or more ADS valves inoperable.

H.1 Be in MODE 3.

AND H.2 Reduce reactor steam dome pressure to 150 psig.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours I.

Two or more low pressure ECCS injection/spray subsystems inoperable for reasons other than Condition A.

OR HPCI System and one or more ADS valves inoperable.

I.1 Enter LCO 3.0.3.

Immediately

RCIC System 3.5.3 BFN-UNIT 2 3.5-12 Amendment No. 253, 286, 334, 351, 360 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS), RPV WATER INVENTORY CONTROL, AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM 3.5.3 RCIC System LCO 3.5.3 The RCIC System shall be OPERABLE.

APPLICABILITY:

MODE 1, MODES 2 and 3 with reactor steam dome pressure > 150 psig.

ACTIONS

NOTE--------------------------------------------------

LCO 3.0.4.b is not applicable to RCIC.

CONDITION REQUIRED ACTION COMPLETION TIME A.

RCIC System inoperable.

A.1 Verify by administrative means High Pressure Coolant Injection System is OPERABLE.

Immediately AND A.2 Restore RCIC System to OPERABLE status.

14 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Reactor Building-to-Suppression Chamber Vacuum Breakers 3.6.1.5 BFN-UNIT 2 3.6-20 Amendment No. 253, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. One line with one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening.

C.1 Restore the vacuum breaker(s) to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months D. Required Action and associated Completion Time of Condition C not met.

D.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months E. Two lines with one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening.

E.1 Restore all vacuum breakers in one line to OPERABLE status.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months F. Required Action and Associated Completion Time of Condition A, B, or E not met.

F.1 Be in MODE 3.

AND F.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.6 BFN-UNIT 2 3.6-22 Amendment No. 253, 360 3.6 CONTAINMENT SYSTEMS 3.6.1.6 Suppression Chamber-to-Drywell Vacuum Breakers LCO 3.6.1.6 Ten suppression chamber-to-drywell vacuum breakers shall be OPERABLE for opening.

AND Twelve suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required suppression chamber-to-drywell vacuum breaker inoperable for opening.

A.1 Restore one vacuum breaker to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C.

One suppression chamber-to-drywell vacuum breaker not closed.

C.1 Close the open vacuum breaker.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months D.

Required Action and associated Completion Time of Condition C not met.

D.1 Be in MODE 3.

AND D.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

RHR Suppression Pool Cooling 3.6.2.3 BFN-UNIT 2 3.6-31 Amendment No. 253, 272, 351, 360 3.6 CONTAINMENT SYSTEMS 3.6.2.3 Residual Heat Removal (RHR) Suppression Pool Cooling LCO 3.6.2.3 Four RHR suppression pool cooling subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One RHR suppression pool cooling subsystem inoperable.

A.1 Restore the RHR suppression pool cooling subsystem to OPERABLE status.

30 days B.

Two RHR suppression pool cooling subsystems inoperable.

B.1 Restore one RHR suppression pool cooling subsystem to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program C.

Required Action and associated Completion Time of Condition A or B not met.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months D.

Three or more RHR suppression pool cooling subsystems inoperable.

D.1 Restore required RHR suppression pool cooling subsystems to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (continued)

RHR Suppression Pool Cooling 3.6.2.3 BFN-UNIT 2 3.6-32 Amendment No. 253, 272, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and associated Completion Time of Condition D not met.

E.1 Be in MODE 3.

AND E.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

RHR Suppression Pool Spray 3.6.2.4 BFN-UNIT 2 3.6-34 Amendment No. 253, 351, 360 3.6 CONTAINMENT SYSTEMS 3.6.2.4 Residual Heat Removal (RHR) Suppression Pool Spray LCO 3.6.2.4 Four RHR suppression pool spray subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One RHR suppression pool spray subsystem inoperable.

A.1 Restore the RHR suppression pool spray subsystem to OPERABLE status.

30 days B.

Two RHR suppression pool spray subsystems inoperable.

B.1 Restore one RHR suppression pool spray subsystem to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program C. Three or more RHR suppression pool spray subsystems inoperable.

C.1 Restore required RHR suppression pool spray subsystems to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months D. Required Action and associated Completion Time not met.

D.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Secondary Containment 3.6.4.1 BFN-UNIT 2 3.6-44 Amendment No. 253, 290, 334, 360 3.6 CONTAINMENT SYSTEMS 3.6.4.1 Secondary Containment LCO 3.6.4.1 The secondary containment shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Secondary containment inoperable.

A.1 Restore secondary containment to OPERABLE status.

4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

SGT System 3.6.4.3 BFN-UNIT 2 3.6-51 Amendment No. 253, 290, 334, 360 3.6 CONTAINMENT SYSTEMS 3.6.4.3 Standby Gas Treatment (SGT) System LCO 3.6.4.3 Three SGT subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One SGT subsystem inoperable.

A.1 Restore SGT subsystem to OPERABLE status.

7 days B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. Two or three SGT subsystems inoperable.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

RHRSW System 3.7.1 BFN-UNIT 2 3.7-4 Amendment No. 254, 323, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and associated Completion Time of Condition A, B, C, or D not met.

E.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months F. Three or more required RHRSW pumps inoperable.

F.1 Restore one RHRSW pump to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months G. Three or more RHRSW subsystems inoperable.

G.1

NOTE-------------

Enter applicable Conditions and Required Actions of LCO 3.4.7 for RHR shutdown cooling made inoperable by the RHRSW System.

Restore one RHRSW subsystem to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months H. Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

EECW System and UHS 3.7.2 BFN-UNIT 2 3.7-7 Amendment No. 254, 351, 360 3.7 PLANT SYSTEMS 3.7.2 Emergency Equipment Cooling Water (EECW) System and Ultimate Heat Sink (UHS)

LCO 3.7.2 The EECW System with three pumps and UHS shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required EECW pump inoperable.

A.1 Restore the required EECW pump to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. Two or more required EECW pumps inoperable.

OR UHS inoperable.

C.1 Be in MODE 3.

AND C.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

CREV System 3.7.3 BFN-UNIT 2 3.7-10 Amendment 254, 283, 290, 302, 308, 334, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. Two CREV subsystems inoperable due to inoperable High Efficiency Particulate Air (HEPA) filter or charcoal adsorbers which do not impact ability of CREV subsystems to meet flowrate requirements specified in the Ventilation Filter Testing Program (VFTP).

C.1 Restore HEPA filter and one charcoal adsorber to OPERABLE status.

7 days D. One CREV subsystem inoperable due to inoperable charcoal adsorber which does not impact the ability of CREV subsystem to meet flowrate requirements specified in the VFTP.

D.1 Restore charcoal adsorber to OPERABLE status.

14 days E.

Required Action and associated Completion Time of Condition A, B, C, or D not met.

E.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months F.

Two CREV subsystems inoperable for reasons other than Condition B or C.

F.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Control Room AC System 3.7.4 BFN-UNIT 2 3.7-14 Amendment No. 254, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Two Unit 1 and 2 control room AC subsystems inoperable.

B.1 Initiate action to restore one Unit 1 and 2 control room AC subsystem to OPERABLE status.

Immediately AND B.2 Place an alternate method of cooling in operation.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months AND B.3 Restore one control room AC subsystem to OPERABLE status.

7 days C. Required Action and associated Completion Time of Condition A or B not met in MODE 1, 2, or 3.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

AC Sources - Operating 3.8.1 BFN-UNIT 2 3.8-6 Amendment No. 253, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME H. Two or more Unit 1 and 2 DGs inoperable.

H.1 Restore all but one Unit 1 and 2 DG to OPERABLE status.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months I.

Required Action and Associated Completion Time of Condition A, B, C, D, E, F, or H not met.

I.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months J.

One or more required offsite circuits and two or more Unit 1 and 2 DGs inoperable.

OR Two required offsite circuits and one or more Unit 1 and 2 DGs inoperable.

OR Two divisions of 480 V load shed logic inoperable.

OR Two divisions of common accident signal logic inoperable.

J.1 Enter LCO 3.0.3.

Immediately (continued)

DC Sources - Operating 3.8.4 BFN-UNIT 2 3.8-23 Amendment No. 253, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and Associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. One or more DG DC electrical power subsystem(s) inoperable.

C.1 Declare associated DG inoperable.

Immediately D. Unit 3 3EB Shutdown Board DC electrical power subsystem inoperable.

D.1 Declare the affected CREV subsystem inoperable.

Immediately

Distribution Systems - Operating 3.8.7 BFN-UNIT 2 3.8-37 Amendment No. 253, 346, 351, 360 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME F.

Unit 1 and 2 4.16 kV Shutdown Board A and B inoperable, for reasons other than Condition J.

OR Unit 1 and 2 4.16 kV Shutdown Board C and D inoperable, for reasons other than Condition J.

NOTE----------------

Enter applicable conditions and required actions of Condition B, C, D, and G when Condition F results in no power source to a required 480 volt board.

F.1 Restore one 4.16 kV Shutdown Board to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months OR In accordance with the Risk Informed Completion Time Program G. One or more required Unit 1 or 3 AC or DC Boards inoperable, for reasons other than Condition J.

G.1 Declare the affected SGT or CREV subsystem inoperable.

Immediately H. Required Action and associated Completion Time of Condition A, B, D, E, F, or J not met.

H.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months I.

Two or more electrical power distribution subsystems inoperable that result in a loss of function, for reasons other than Condition J.

I.1 Enter LCO 3.0.3.

Immediately (continued)

TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-296 BROWNS FERRY NUCLEAR PLANT, UNIT 3 AMENDMENT TO SUBSEQUENT RENEWED FACILITY OPERATING LICENSE Amendment No. 320 Subsequent Renewed License No. DPR-68

1.

The U.S. Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Tennessee Valley Authority (the licensee) dated April 10, 2025, as supplemented by letter July 14, 2025, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in Title 10 of the Code of Federal Regulations (10 CFR) Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Subsequent Renewed Facility Operating License No. DPR-68 is hereby amended to read as follows:

(2)

Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 320, are hereby incorporated in this subsequent renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of its date of issuance and shall be implemented within 90 days from the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION David Wrona, Chief Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Date of Issuance:

DAVID WRONA Digitally signed by DAVID WRONA Date: 2025.12.18 14:07:04 -05'00'

ATTACHMENT TO LICENSE AMENDMENT NO. 320 SUBSEQUENT RENEWED FACILITY OPERATING LICENSE NO. DPR-68 BROWNS FERRY NUCLEAR PLANT, UNIT 3 DOCKET NO. 50-296 Replace the following pages of the Subsequent Renewed Facility Operating License and Appendix A, Technical Specifications (TSs), with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Remove Insert License DPR-68 License DPR-68 Page 3 Page 3 TSs TSs 3.3-76 3.3-76 3.5-1 3.5-1 3.5-3 3.5-3 3.5-12 3.5-12 3.6-20 3.6-20 3.6-22 3.6-22 3.6-31 3.6-31 3.6-32 3.6-32 3.6-34 3.6-34 3.6-44 3.6-44 3.6-51 3.6-51 3.7-4 3.7-4 3.7-7 3.7-7 3.7-10 3.7-10 3.7-14 3.7-14 3.8-6 3.8-6 3.8-23 3.8-23 3.8-37 3.8-37

Subsequent Renewed License No. DPR-68 Amendment No. 320 accordance with the limitations for storage and amounts required for reactor operation, as described in the Final Safety Analysis Report as supplemented and amended; (3)

Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use at any time any byproduct, source, and special nuclear material as sealed neutron sources for reactor startup, sealed sources for reactor instrumentation and radiation monitoring equipment calibration, and as fission detectors in amounts as required; (4)

Pursuant to the Act and 10 CFR Parts 30, 40, and 70, to receive, possess, and use in amounts as required any byproduct, source, or special nuclear material without restriction to chemical or physical form for sample analysis or equipment and instrument calibration or associated with radioactive apparatus or components; (5)

Pursuant to the Act and 10 CFR Parts 30 and 70, to possess but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C.

This subsequent renewed operating license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations in 10 CFR Chapter I: Part 20, Section 30.34 of Part 30, Section 40.41 of Part 40, Sections 50.54 and 50.59 of Part 50, and Section 70.32 of Part 70; is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified or incorporated below:

(1)

Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 3952 megawatts thermal.

(2)

Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 320, are hereby incorporated in this subsequent renewed operating license. The licensee shall operate the facility in accordance with the Technical Specifications.

For Surveillance Requirements (SRs) that are new in Amendment 212 to Facility Operating License DPR-68, the first performance is due at the end of the first surveillance interval that begins at implementation of the Amendment 212. For SRs that existed prior to Amendment 212, including SRs with modified acceptance criteria and SRs whose frequency of performance is being extended, the first performance is due at the end of the first surveillance interval that begins on the date the surveillance was last performed prior to implementation of Amendment 212.

(3)

The licensee is authorized to relocate certain requirements included in Appendix A and the former Appendix B to licensee-controlled documents.

RPS Electric Power Monitoring 3.3.8.2 BFN-UNIT 3 3.3-76 Amendment No. 213, 320 3.3 INSTRUMENTATION 3.3.8.2 Reactor Protection System (RPS) Electric Power Monitoring LCO 3.3.8.2 Two RPS electric power monitoring assemblies shall be OPERABLE for each inservice RPS motor generator set or alternate power supply.

APPLICABILITY:

MODES 1, 2, and 3, MODES 4 and 5 with any control rod withdrawn from a core cell containing one or more fuel assemblies.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or both inservice power supplies with one electric power monitoring assembly inoperable.

A.1 Remove associated inservice power supply(s) from service.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B. One or both inservice power supplies with both electric power monitoring assemblies inoperable.

B.1 Remove associated inservice power supply(s) from service.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months C. Required Action and associated Completion Time of Condition A or B not met in MODE 1, 2, or 3.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

ECCS - Operating 3.5.1 BFN-UNIT 3 3.5-1 Amendment No. 212, 229, 244, 294, 311, 320 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS), RPV WATER INVENTORY CONTROL, AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM 3.5.1 ECCS - Operating LCO 3.5.1 Each ECCS injection/spray subsystem and the Automatic Depressurization System (ADS) function of six safety/relief valves shall be OPERABLE.

APPLICABILITY:

MODE 1, MODES 2 and 3, except high pressure coolant injection (HPCI) and ADS valves are not required to be OPERABLE with reactor steam dome pressure 150 psig.

ACTIONS

NOTE--------------------------------------------------

LCO 3.0.4.b is not applicable to HPCI.

CONDITION REQUIRED ACTION COMPLETION TIME A.

One low pressure ECCS injection/spray subsystem inoperable.

OR One low pressure coolant injection (LPCI) pump in both LPCI subsystems inoperable.

A.1 Restore low pressure ECCS injection/spray subsystem(s) to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

ECCS - Operating 3.5.1 BFN-UNIT 3 3.5-3 Amendment No. 212, 229, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME G. Required Action and associated Completion Time of Condition C, D, E, or F not met.

G.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months H. Two or more ADS valves inoperable.

H.1 Be in MODE 3.

AND H.2 Reduce reactor steam dome pressure to 150 psig.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours I.

Two or more low pressure ECCS injection/spray subsystems inoperable for reasons other than Condition A.

OR HPCI System and one or more ADS valves inoperable.

I.1 Enter LCO 3.0.3.

Immediately

RCIC System 3.5.3 BFN-UNIT 3 3.5-12 Amendment No. 212, 244, 294, 311, 320 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS), RPV WATER INVENTORY CONTROL, AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM 3.5.3 RCIC System LCO 3.5.3 The RCIC System shall be OPERABLE.

APPLICABILITY:

MODE 1, MODES 2 and 3 with reactor steam dome pressure > 150 psig.

ACTIONS

NOTE--------------------------------------------------

LCO 3.0.4.b is not applicable to RCIC.

CONDITION REQUIRED ACTION COMPLETION TIME A.

RCIC System inoperable.

A.1 Verify by administrative means High Pressure Coolant Injection System is OPERABLE.

Immediately AND A.2 Restore RCIC System to OPERABLE status.

14 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Reactor Building-to-Suppression Chamber Vacuum Breakers 3.6.1.5 BFN-UNIT 3 3.6-20 Amendment No. 212, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. One line with one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening.

C.1 Restore the vacuum breaker(s) to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months D. Required Action and associated Completion Time of Condition C not met.

D.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months E. Two lines with one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening.

E.1 Restore all vacuum breakers in one line to OPERABLE status.

1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months F. Required Action and Associated Completion Time of Condition A, B, or E not met.

F.1 Be in MODE 3.

AND F.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

Suppression Chamber-to-Drywell Vacuum Breakers 3.6.1.6 BFN-UNIT 3 3.6-22 Amendment No. 212, 320 3.6 CONTAINMENT SYSTEMS 3.6.1.6 Suppression Chamber-to-Drywell Vacuum Breakers LCO 3.6.1.6 Ten suppression chamber-to-drywell vacuum breakers shall be OPERABLE for opening.

AND Twelve suppression chamber-to-drywell vacuum breakers shall be closed, except when performing their intended function.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required suppression chamber-to-drywell vacuum breaker inoperable for opening.

A.1 Restore one vacuum breaker to OPERABLE status.

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C.

One suppression chamber-to-drywell vacuum breaker not closed.

C.1 Close the open vacuum breaker.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months D.

Required Action and associated Completion Time of Condition C not met.

D.1 Be in MODE 3.

AND D.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

RHR Suppression Pool Cooling 3.6.2.3 BFN-UNIT 3 3.6-31 Amendment No. 212, 230, 311, 320 3.6 CONTAINMENT SYSTEMS 3.6.2.3 Residual Heat Removal (RHR) Suppression Pool Cooling LCO 3.6.2.3 Four RHR suppression pool cooling subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One RHR suppression pool cooling subsystem inoperable.

A.1 Restore the RHR suppression pool cooling subsystem to OPERABLE status.

30 days B.

Two RHR suppression pool cooling subsystems inoperable.

B.1 Restore one RHR suppression pool cooling subsystem to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program C.

Required Action and associated Completion Time of Condition A or B not met.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months D.

Three or more RHR suppression pool cooling subsystems inoperable.

D.1 Restore required RHR suppression pool cooling subsystems to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (continued)

RHR Suppression Pool Cooling 3.6.2.3 BFN-UNIT 3 3.6-32 Amendment No. 212, 230, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and associated Completion Time of Condition D not met.

E.1 Be in MODE 3.

AND E.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

RHR Suppression Pool Spray 3.6.2.4 BFN-UNIT 3 3.6-34 Amendment No. 212, 311, 320 3.6 CONTAINMENT SYSTEMS 3.6.2.4 Residual Heat Removal (RHR) Suppression Pool Spray LCO 3.6.2.4 Four RHR suppression pool spray subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One RHR suppression pool spray subsystem inoperable.

A.1 Restore the RHR suppression pool spray subsystem to OPERABLE status.

30 days B.

Two RHR suppression pool spray subsystems inoperable.

B.1 Restore one RHR suppression pool spray subsystem to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program C. Three or more RHR suppression pool spray subsystems inoperable.

C.1 Restore required RHR suppression pool spray subsystems to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months D. Required Action and associated Completion Time not met.

D.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Secondary Containment 3.6.4.1 BFN-UNIT 3 3.6-44 Amendment No. 212, 249, 294, 320 3.6 CONTAINMENT SYSTEMS 3.6.4.1 Secondary Containment LCO 3.6.4.1 The secondary containment shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Secondary containment inoperable.

A.1 Restore secondary containment to OPERABLE status.

4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

SGT System 3.6.4.3 BFN-UNIT 3 3.6-51 Amendment No. 212, 249, 294, 320 3.6 CONTAINMENT SYSTEMS 3.6.4.3 Standby Gas Treatment (SGT) System LCO 3.6.4.3 Three SGT subsystems shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One SGT subsystem inoperable.

A.1 Restore SGT subsystem to OPERABLE status.

7 days B. Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. Two or three SGT subsystems inoperable.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

RHRSW System 3.7.1 BFN-UNIT 3 3.7-4 Amendment No. 214, 283, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and associated Completion Time of Condition A, B, C, or D not met.

E.1

NOTE-------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months F. Three or more required RHRSW pumps inoperable.

F.1 Restore one RHRSW pump to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months G. Three or more RHRSW subsystems inoperable.

G.1

NOTE-------------

Enter applicable Conditions and Required Actions of LCO 3.4.7 for RHR shutdown cooling made inoperable by the RHRSW System.

Restore one RHRSW subsystem to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months H. Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

EECW System and UHS 3.7.2 BFN-UNIT 3 3.7-7 Amendment No. 214, 311, 320 3.7 PLANT SYSTEMS 3.7.2 Emergency Equipment Cooling Water (EECW) System and Ultimate Heat Sink (UHS)

LCO 3.7.2 The EECW System with three pumps and UHS shall be OPERABLE.

APPLICABILITY:

MODES 1, 2, and 3.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A.

One required EECW pump inoperable.

A.1 Restore the required EECW pump to OPERABLE status.

7 days OR In accordance with the Risk Informed Completion Time Program B.

Required Action and associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. Two or more required EECW pumps inoperable.

OR UHS inoperable.

C.1 Be in MODE 3.

AND C.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 36 hours

CREV System 3.7.3 BFN-UNIT 3 3.7-10 Amendment 214, 241, 249, 261, 267, 294, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. Two CREV subsystems inoperable due to inoperable High Efficiency Particulate Air (HEPA) filter or charcoal adsorbers which do not impact ability of CREV subsystems to meet flowrate requirements specified in the Ventilation Filter Testing Program (VFTP).

C.1 Restore HEPA filter and one charcoal adsorber to OPERABLE status.

7 days D. One CREV subsystem inoperable due to inoperable charcoal adsorber which does not impact the ability of CREV subsystem to meet flowrate requirements specified in the VFTP.

D.1 Restore charcoal adsorber to OPERABLE status.

14 days E.

Required Action and associated Completion Time of Condition A, B, C, or D not met.

E.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months F.

Two CREV subsystems inoperable for reasons other than Condition B or C.

F.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

Control Room AC System 3.7.4 BFN-UNIT 3 3.7-14 Amendment No. 214, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Two Unit 3 control room AC subsystems inoperable.

B.1 Initiate action to restore one Unit 3 control room AC subsystem to OPERABLE status.

Immediately AND B.2 Place an alternate method of cooling in operation.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months AND B.3 Restore one control room AC subsystem to OPERABLE status.

7 days C. Required Action and associated Completion Time of Condition A or B not met in MODE 1, 2, or 3.

C.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (continued)

AC Sources - Operating 3.8.1 BFN-UNIT 3 3.8-6 Amendment No. 212, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME H. Two or more Unit 3 DGs inoperable.

H.1 Restore all but one Unit 3 DG to OPERABLE status.

2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months I.

Required Action and Associated Completion Time of Condition A, B, C, D, E, F, or H not met.

I.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months J. One or more required offsite circuits and two or more Unit 3 DGs inoperable.

OR Two required offsite circuits and one or more Unit 3 DGs inoperable.

OR Two divisions of 480 V load shed logic inoperable.

OR Two divisions of common accident signal logic inoperable.

J.1 Enter LCO 3.0.3.

Immediately (continued)

DC Sources - Operating 3.8.4 BFN-UNIT 3 3.8-23 Amendment No. 212, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and Associated Completion Time of Condition A not met.

B.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months C. One or more DG DC electrical power subsystem(s) inoperable.

C.1 Declare associated DG inoperable.

Immediately D. One or more Unit 1 and 2 Shutdown Board DC electrical power subsystem(s) inoperable.

D.1 Declare the affected SGT or CREV subsystem inoperable.

Immediately

Distribution Systems - Operating 3.8.7 BFN-UNIT 3 3.8-37 Amendment No. 212, 306, 311, 320 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME F. Unit 3 4.16 kV Shutdown Board 3EA and 3EB inoperable.

OR Unit 3 4.16 kV Shutdown Board 3EC and 3ED inoperable.

NOTE----------------

Enter applicable conditions and required actions of Condition B, C, D, and G when Condition F results in no power source to a required 480 volt board.

F.1 Restore one 4.16 kV Shutdown Board to OPERABLE status.

8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months OR In accordance with the Risk Informed Completion Time Program G. One or more required Unit 1 or 2 AC or DC Boards inoperable, for reasons other than Condition J.

G.1 Declare the affected SGT or CREV subsystem inoperable.

Immediately H. Required Action and associated Completion Time of Condition A, B, D, E, F, or J not met.

H.1

NOTE ------------

LCO 3.0.4.a is not applicable when entering MODE 3.

Be in MODE 3.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months I.

Two or more electrical power distribution subsystems inoperable that result in a loss of function.

I.1 Enter LCO 3.0.3.

Immediately (continued)

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 337, 360, AND 320 TO SUBSEQENT RENEWED FACILITY OPERATING LICENSE NOS. DPR-33, DPR-52, AND DPR-68 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, AND 50-296

1.0 INTRODUCTION

By application dated April 10, 2025 (Reference 1), as supplemented by letter July 14, 2025 (Reference 2), the Tennessee Valley Authority (TVA, the licensee), submitted a license amendment request (LAR) for Browns Ferry Nuclear Plant (Browns Ferry or BFN), Units 1, 2, and 3. The requested changes are the adoption of Technical Specifications Task Force (TSTF)

Traveler TSTF-423, Revision 1, Technical Specifications End States, NEDC 32988-A, (Reference 3). TSTF-423, Revision 1, incorporates the Boiling Water Reactor (BWR) Owners Group (BWROG) approved Topical Report NEDC-32988, Revision 2, Technical Justification to Support Risk Informed Modification to Selected Required Action End States for BWR Plants (Reference 4), into the BWR Standard Technical Specifications (STS). The changes proposed in TSTF-423 are based on Revision 3 of the BWR STS NUREGs1.

The supplement dated July 14, 2025, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the U.S. Nuclear Regulatory Commission (the Commission or NRC) staffs original proposed no significant hazards consideration determination as published in the Federal Register on June 10, 2025 (90 FR 24417).

TSTF-423 is one of the industrys initiatives developed under the Risk Management Technical Specifications (RMTS) program. These initiatives are intended to maintain or improve safety through the incorporation of risk assessment and management techniques in technical specifications (TSs). The program is designed to reduce unnecessary burden and make TS 1 NUREG-1433, Revision 3, Standard Technical Specifications General Electric Plants, BWR/4 Specifications, Volumes 1 and 2 (ML041910194 and ML041910212, respectively).

NUREG-1434, Revision 3, Standard Technical Specifications General Electric Plants, BWR/6 Specifications, Volumes 1 and 2 (ML041910204 and ML041910223, respectively).

requirements consistent with the Commissions other risk-informed regulatory requirements, particularly the maintenance rule.

The regulation at Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36, Technical specifications, states, in part, that: [w]hen a limiting condition for operation of a nuclear reactor is not met, the licensee shall shutdown the reactor or follow the remedial action permitted by the technical specification until the condition can be met. The STS and most plant TS provide a completion time (CT) for the plant to meet the limiting condition for operation (LCO). If the LCO or the remedial action cannot be met within the CT, then the reactor is required to be shut down. When the STS and individual plant TSs were written, the shutdown condition or end state specified was usually cold shutdown.

The STS for BWR plants define five operational modes. In general, they are:

Mode 1-Power Operation. The reactor mode switch is in run position.

Mode 2 - Reactor Startup. The reactor mode switch is in refuel position (with all reactor vessel head closure bolts fully tensioned) or in startup/hot standby position.

Mode 3 - Hot Shutdown. The reactor coolant system (RCS) temperature is above 200 degrees Fahrenheit (F) (TS specific) and the reactor mode switch is in shutdown position (with all reactor vessel head closure bolts fully tensioned).

Mode 4 - Cold Shutdown. The RCS temperature is equal to, or less than 200 degrees F, and the reactor mode switch is in shutdown position (with all reactor vessel head closure bolts fully tensioned).

Mode 5 - Refueling. The reactor mode switch is in shutdown or refuel position, and one or more reactor vessel head closure bolts are less than fully tensioned.

Criticality is not allowed in Modes 3 through 5.

Topical Report NEDC-32988, Revision 2, provides the technical basis to change certain required end states when the TS Actions for remaining in power operation cannot be met within the CTs. Most of the requested TS changes permit an end state of hot shutdown (Mode 3), if risk is assessed and managed, rather than an end state of cold shutdown (Mode 4) contained in the current TS. The request was limited to those end states where: (1) entry into the shutdown mode is for a short interval, (2) entry is initiated by inoperability of a single train of equipment or a restriction on a plant operational parameter, unless otherwise stated in the applicable TS, and (3) the primary purpose is to correct the condition and return to power operation as soon as is practical.

TSTF-423 generally allows a Mode 3 end state rather than a Mode 4 end state for selected conditions in order to perform short-duration repairs which necessitate exiting the original Mode of operation. Short duration repairs are on the order of 2-to-3 days, but not more than a week.

2.0 REGULATORY EVALUATION

In 10 CFR 50.36, the Commission established its regulatory requirements related to the content of TSs. Pursuant to 10 CFR 50.36(c), TSs are required to include items in the following five specific categories related to station operation: (1) safety limits, limiting safety system settings, and limiting control settings; (2) LCOs; (3) surveillance requirements (SRs); (4) design features; and (5) administrative controls. As stated in 10 CFR 50.36(c)(2)(i), the Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When an limiting condition for operation of a nuclear reactor is not met, the licensee shall shutdown the reactor or follow any remedial action permitted by the technical specifications.

In describing the basis for changing end states, NEDC-32988-A (Reference 4) states:

Cold shutdown is normally required when an inoperable system or train cannot be restored to an operable status within the allowed time. Going to cold shutdown results in the loss of steam-driven systems, challenges the shutdown heat removal systems, and requires restarting the plant. A preferred operational mode is one that maintains adequate risk levels while repairs are completed without causing unnecessary challenges to plant equipment during shutdown and startup transitions.

In the end state changes under consideration in this LAR, a problem with a component or train has, or will, result in a failure to meet the TS, and a controlled shutdown is directed because a TS Action requirement cannot be met within the TS CT.

The original TSs and the design basis analyses were developed under the perception that putting a plant in cold shutdown would result in the safest condition. The assumption was also that the design basis analyses would bound credible shutdown accidents. In the late 1980s and early 1990s, the NRC and licensees recognized that this idea was not always correct and took actions to improve shutdown operation. During the same time STS were developed, and many licensees improved their TSs.

Controlling shutdown risk encompasses control of conditions that can cause potential initiating events and responses to those initiating events that do occur. Initiating events are a function of equipment malfunctions and human error. Responses to events are a function of plant sensitivity, ongoing activities, human error, defense-in-depth, and additional equipment malfunctions.

In practice, the risk during shutdown operations is often addressed via voluntary actions and application of 10 CFR 50.65, Requirements for monitoring the effectiveness of maintenance at nuclear power plants (i.e., the Maintenance Rule). Paragraph 50.65(a)(4) states:

Before performing maintenance activities... the licensee shall assess and manage the increase in risk that may result from the proposed maintenance activities. The scope of the assessment may be limited to structures, systems, and components that a risk-informed evaluation process has shown to be significant to public health and safety.

Regulatory Guide (RG) 1.160, Monitoring the Effectiveness of Maintenance at Nuclear Power Plants (Reference 5), provides guidance on implementing the provisions of 10 CFR 50.65(a)(4) by endorsing NUMARC 93-01, Revision 4F (Reference 6), which has been endorsed by the NRC. The changes in TSTF-423 are consistent with the regulations and associated regulatory guidance noted above.

3.0 TECHNICAL EVALUATION

The changes proposed in the LAR are consistent with the changes proposed and justified in Topical Report NEDC-32988-A, Revision 2, and approved by the associated NRC safety evaluation (SE) (Reference 7). The evaluation included in the NRC staff SE, as appropriate and applicable to the changes of TSTF-423, is summarized here and differences from the SE are justified. In its application, the licensee commits to TSTF-IG-05-02, Revision 2, Implementation Guidance for TSTF-423, Revision 1, Technical Specifications End States, NEDC-32988-A (Reference 8), which provides guidance for implementing the maintenance rule, risk assessment, and risk management actions associated with the end state changes. The NRC accepted this guidance, and its adoption, which is included in the traveler and committed to in the LAR, as a plant requirement. An overview of the generic evaluation and associated risk assessment is provided below, along with a summary of the associated TS changes justified by topical report NEDC-32988-A, Revision 2.

This LAR only changes the end state allowed by TS when a Condition is not met. The plant Conditions, Required Actions (RAs), and Completion Times (CTs) vary depending on plant design. Generally, instead of a plant being required to enter cold shutdown (Mode 4), the new end state allows operation in hot shutdown (Mode 3) for a period of time, to correct the condition. The other Conditions, RAs, and CTs for the TS involved are unchanged. The risk analysis demonstrated that it is acceptable to remain in Mode 3 instead of entering Mode 4 for some Conditions.

3.1 Risk Assessment The objective of the BWROG topical report, NEDC-32988-A (Reference 4), risk assessment was to show that any risk increases associated with the changes in TS end states are either negligible or result in a decrease in risk. The topical report documents a risk-informed analysis of the proposed TS changes. Probabilistic risk assessment (PRA) results and insights are used, in combination with results of deterministic assessments, to identify and propose changes in end states for all BWR plants. This evaluation was performed in accordance with guidance provided in Regulatory Guide (RG) 1.174, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis (Reference 9), and RG 1.177, An Approach for Plant-Specific, Risk-Informed Decision Making:

Technical Specifications (Reference 10). The three-tiered approach documented in RG 1.177 was followed.

The first tier includes the assessment of the risk impact of the proposed change for comparison to acceptance guidelines consistent with the Commissions Safety Goal Policy Statement, as documented in RG 1.174. This ensures that there are no unacceptable temporary risk increases resulting from the TS change, such as when equipment is taken out of service. The second tier addresses the need to preclude potentially high-risk configurations, which could result if additional equipment is removed from service while in the condition for which the end state is modified, as allowed by this TS change. The third tier addresses the application of 10 CFR 50.65(a)(4) of the Maintenance Rule for identifying potential risk significant configurations due to activities while a plant is in a modified end state and taking appropriate actions to avoid them.

The BWROGs risk assessment approach was found comprehensive and acceptable in the SE for the topical report (Reference 7). In addition, the analyses show that the three-tiered approach criteria for allowing TS changes are met as follows:

Risk Impact of the Proposed Change (Tier 1). The risk changes associated with the TS changes in TSTF-423, in terms of mean yearly increases in core damage frequency (CDF) and large early release frequency (LERF), are risk neutral or risk beneficial. In addition, there are no significant temporary risk increases, as defined by RG 1.177 criteria, associated with the implementation of the TS end state changes.

Avoidance of Risk Significant Configurations (Tier 2). The risk analyses, which are based on single LCOs, show that there are no high-risk configurations associated with the TS end state changes due to remaining in Mode 3 with the equipment affected by the proposed changes inoperable. The reliability of redundant trains is normally covered by a single LCO. When multiple LCOs occur, which affect trains in several systems, the plants risk-informed configuration risk management program (CRMP), or the plant-specific program for implementing the Maintenance Rule (10 CFR 50.65(a)(4)), ensures that high-risk configurations are avoided. As part of the implementation of TSTF-423, the licensee has committed to follow Section 11 of NUMARC 93-01 and include guidance in appropriate plant procedures and/or administrative controls to preclude high-risk plant configurations when the plant is at the proposed end state. The original traveler referred to Revision 3 of NUMARC 93-01. The licensee stated that they are currently following Revision 4F of NUMARC 93-01, which was endorsed by the NRC in RG 1.160, Revision 4. The NRC staff finds that such guidance is adequate for preventing risk significant plant configurations.

Configuration Risk Management (Tier 3). As stated in the LAR, the licensee has a program to comply with 10 CFR 50.65(a)(4) to assess and manage the risk from maintenance activities. This program can support a licensees decision in selecting the appropriate actions to control risk for most cases in which a TS is entered.

The generic risk impact of the end state mode change was evaluated subject to the following assumptions, which are incorporated into the TS, TS Bases, and TSTF-IG-05-02 (Reference 8):

The entry into the end state is initiated by the inoperability of a single train of equipment or a restriction on a plant operational parameter, unless otherwise stated in the applicable TS.

The primary purpose of entering the end state is to correct the condition and return to power as soon as is practical.

When Mode 3 is entered as the end state, the time the reactor coolant pressure is above 500 pounds per square inch gauge (psig) will be minimized. If 500 psig is exceeded for more than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , the associated plant risk will be assessed and managed.

These assumptions are consistent with typical entries into Mode 3 for short duration repairs, which is the intended use of the TS end state changes. The NRC staff concludes that going to Mode 3 (hot shutdown) instead of going to Mode 4 (cold shutdown) to carry out equipment repairs that are of short duration, does not have an adverse effect on plant risk.

, Regulatory Commitments, of the LAR states:

TVA will follow the guidance established in Section11 of NUMARC 93-01, Industry Guidance for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, Nuclear Management and Resource Council.

Additionally, the licensee also commits to the following:

TVA will follow the guidance established in TSTF-IG-05-02, Revision 2, Implementation Guidance for TSTF-423, Revision 1, Technical Specifications End States, NEDC-32988-A.

By following the Implementation Guidance, the licensee will ensure that defense-in-depth is maintained for key safety functions by ensuring availability of Tier 2 systems/equipment necessary for safe shutdown. Therefore, the NRC staff finds the licensees commitments to be acceptable.

3.2 Assessment of TS Changes The changes proposed by TVA in adopting TSTF-423, Revision 1, are consistent with Topical Report NEDC-32988 (Reference 4), as approved by NRC staff SE (Reference 7). The proposed changes are described below, including a synopsis of the STS LCO and a conclusion regarding the acceptability of the change.

TSTF-423, Revision 1, modifies each RA with the preferred Mode 3 end state, by a note stating, LCO 3.0.4.a is not applicable when entering MODE 3. Adding this note into the TSs provides assurance that an inappropriate entry into Mode 3 utilizing the provisions of LCO 3.0.4.a during startup is not made. Therefore, the NRC staff finds the inclusion of this note for the affected TS to be acceptable.

The licensee did not incorporate all the changes allowed by TSTF-423, as noted in corresponding sections below. The licensee also identified changes and variations required due to the plant-specific TS being different from the STS on which TSTF-423 is based. Table 1 of of the LAR provides a brief description of the variations and identifies the changes that were not incorporated for the Browns Ferry TSs. The TSs that have variations for plant-specific adoption are described and discussed in the appropriate sections below.

For variations due to numbering differences between the Browns Ferry TSs and the STSs, on which the TSTF traveler is based, the changes are merely administrative in nature and do not affect the technical conclusions of this SE.

Variations that affect the nomenclature of equipment, the number of components or subsystems to be operable, or the RA timing do not affect the NRC staff technical conclusions regarding the end states for the LCOs. The licensing bases for the Browns Ferry units include a number of differences from the assumptions on which the STS are based. The Browns Ferry TS LCOs were developed considering these differences. Since the only changes resulting from this LAR are the adoption of new end states, TS differences in Conditions and RAs due to variations between the plant-specific design and STS assumptions regarding design are irrelevant. The plant Conditions, RAs, and CTs have been approved for the Browns Ferry units. The proposed end states will put the Browns Ferry units in the same end state condition as the TSTF considering the plant configuration requiring the end state differences.

The following subsections describe the proposed changes, including a synopsis of the TS LCO, and a conclusion of acceptability. To help in understanding the changes and the descriptions in this section, it may be helpful to refer to the TS markups in Enclosure 1 to the LAR, Attachments 1.1, 1.2, and 1.3 for Units 1, 2, and 3, respectively. In some cases, the entire TS is not provided in the markup so referring to the plant TSs may also be helpful [ML052780019 (Unit 1); ML052780020 (Unit 2); ML052780411 (Unit 3)]. The TSs are almost identical between the units with a few differences. The differences are noted in the discussions below where appropriate.

3.2.1 LCO 3.3.8.2: Reactor Protection System (RPS) Electric Power Monitoring The RPS Electric Power Monitoring System is provided to isolate the RPS bus from the normal uninterruptible power supply or an alternate power supply in the event of over voltage, under voltage, or under frequency. This system protects the load connected to the RPS bus against unacceptable voltage and frequency conditions and forms an important part of the primary success path of the essential safety circuits. Some of the essential equipment powered from the RPS buses include the RPS logic, scram solenoids, and various valve isolation logic. The TS change allows the plant to remain in Mode 3 until the repairs are completed.

LCO: For Modes 1, 2, 3, and Modes 4 and 5 with any control rod withdrawn from a core cell containing one or more fuel assemblies, two RPS electric power monitoring assemblies shall be OPERABLE for each in-service RPS motor generator set, or alternate power supply.

Condition Requiring Entry into End State: If the LCO cannot be met, the associated in-service power supply(s) must be removed from service within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months (Required Action B.1). In Modes 1, 2, and 3, if the in-service power supply(s) cannot be removed from service within the allotted time, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Actions C.1 and C.2).

Modification for End State Required Actions: The change allows the plant to remain in Mode 3 until the repair actions are completed. Required Action C.2, which required the plant to be in Mode 4, is deleted, allowing the plant to stay in Mode 3 while completing repairs.

Assessment: To reach Mode 3, per the TS, there must be a functioning power supply with degraded protective circuitry in operation. However, the over voltage, under voltage, or under frequency condition must exist for an extended period to cause damage. There is a low probability of this occurring in the short period of time that the plant would remain in Mode 3 without this protection.

The specific failure condition of interest is not risk significant for BWR PRAs. If the required restoration actions cannot be completed within the specified time, going into Mode 4 at Browns Ferry would cause loss of the high-pressure reactor core isolation cooling system (RCIC) and loss of the power conversion system (condenser/feedwater), and would require activating the residual heat removal (RHR) system. In addition, emergency operating procedures (EOPs) direct the operator to take control of the depressurization function if low pressure injection/spray systems are needed for reactor pressure vessel (RPV) water makeup and cooling. Based on the low probability of loss of the RPS power monitoring system during the infrequent and limited time in Mode 3 and the number of systems available in Mode 3, the NRC staff concludes that the risks of staying in Mode 3 are approximately the same as and, in some cases, lower than the risks of going to the Mode 4 end state; therefore, the change is acceptable.

3.2.2 LCO 3.4.3: Safety Relief Valves The licensee did not request any changes to LCO 3.4.3.

3.2.3 LCO 3.5.1: Emergency Core Cooling Systems (ECCS) - (Operating)

The ECCS provides cooling water to the core in the event of a loss-of-coolant accident (LOCA).

This set of ECCS TSs provides the operability requirements for the various ECCS subsystems as described below. This TS change would delete the secondary actions. The plant can remain in Mode 3 until the required repair actions are completed. The reactor is not depressurized.

LCO: Each ECCS injection/spray subsystem and the automatic depressurization system (ADS) function of six safety/relief valves shall be operable.

Conditions requiring entry into end state: If the LCO cannot be met, the following actions must be taken for the listed Conditions:

A. If one low pressure ECCS injection/spray subsystem is inoperable or one low pressure coolant injection (LPCI) pump in both LPCI subsystems is inoperable, the subsystem(s) must be restored to operable status in 7 days or in accordance with the risk-informed completion time (RICT).

B. If the inoperable low pressure ECCS injection/core spray subsystem cannot be restored to operable status, the unit must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

C. If the high-pressure coolant injection (HPCI) system is inoperable, the reactor core isolation cooling (RCIC) system must be verified to be operable by administrative means immediately and the HPCI system restored to operable status within 14 days or in accordance with the RICT.

D. If the HPCI system is inoperable and Condition A (above) is entered, the HPCI system or the low pressure ECCS subsystem must be restored to operable within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or in accordance with the RICT.

E. If one ADS valve is inoperable, it must be restored to operable status within 14 days or in accordance with the RICT.

F. If one ADS valve is inoperable and Condition A (above) is entered, the ADS valve must be restored to operable status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or in accordance with the RICT, or the low pressure ECCS injection/spray subsystem must be restored to operable within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or in accordance with the RICT.

G. If two or more ADS valves are inoperable, or the required actions and associated CT of Conditions C, D, E or F cannot be met, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and the reactor steam dome pressure must be reduced to less than or equal to 150 psig within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

H. If two or more low pressure ECCS injection/spray subsystems are inoperable for reasons other than Condition A (above) or the HPCI system and one or more ADS valves are inoperable, the plant must enter LCO 3.0.3 immediately.

Modification for Required Actions:

A. No change B. If the ECCS injection or spray system is inoperable, the plant must be placed in Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The plant is not taken into Mode 4 (cold shutdown).

C. No change D. No change E. No change F. No change G. Condition G is split into G and H. A new Condition G retains some of the original Condition G requirements and assigns a new end state. The new Condition G states if the Actions and associated CTs described in C, D, E, or F (above) are not met, the plant is required to be in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

H. Original Condition G is renumbered to H. Condition H contains the requirements from the original Condition G that if 2 or more ADS valves are inoperable the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and the reactor steam dome pressure must be reduced to less than or equal to 150 psig within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

I.

Original Condition H is renumbered to letter I. No other changes are made.

Assessment: The BWROG performed a comparative PRA evaluation in TR NEDC-32988-A of the core damage risks of operation in the current end state (i.e., Mode 4) and the proposed Mode 3 end state (Reference 4). The evaluation indicates that the core damage risks are lower in Mode 3 than in the current end state Mode 4. Going to Mode 4 for one ECCS subsystem or one ADS valve would cause loss of the high-pressure steam-driven injection system (RCIC/HPCI), and loss of the power conversion system (condenser/feedwater), and require activating the RHR system. In addition, EOPs direct the operator to take control of the depressurization function if low-pressure injection/spray systems are needed for RPV water makeup and cooling. Based on the low probability of loss of the reactor coolant inventory and the number of systems available in Mode 3, the NRC staff concludes in the SE to the BWR topical report that the risks of staying in Mode 3 are approximately the same as, and in some cases lower than, the risks of going to the Mode 4 end state.

Based on the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC finds the change acceptable.

3.2.4 LCO 3.5.3: RCIC System The function of the RCIC system is to provide reactor coolant makeup during loss of feedwater and other transient events. This TS provides the operability requirements for the RCIC system as described below. The TS change allows the plant to remain in Mode 3 until the repairs are completed.

LCO: The RCIC system must be operable during Mode 1 and Mode 2, and Mode 3 when the reactor steam dome pressure is greater than 150 psig.

Condition requiring entry into end state: If the LCO cannot be met, the following actions must be taken: (a) immediately verify by administrative means that the HPCI system is operable, and (b) restore the RCIC system to operable status within 14 days or in accordance with the RICT. If either or both actions cannot be completed within the allotted time, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and the reactor steam dome pressure must be reduced to less than 150 psig within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

Modification for end state required actions: This TS change allows the plant to remain in Mode 3 (hot shutdown) until the required repairs are completed. The reactor steam dome pressure is not reduced to less than 150 psig.

Assessment: This change would allow the inoperable RCIC system to be repaired in a plant operating mode with lower risk and without challenging the normal shutdown systems. The BWROG topical report did a comparative PRA evaluation of the core damage risks of operation in the current end state (Mode 3 with steam dome pressure 150 psig) and in the proposed Mode 3 end state. The evaluation indicates that the core damage risks are lower in Mode 3 than in Mode 4. Going to Mode 3 with reactor steam dome pressure less than 150 psig for inoperability of RCIC would also cause loss of the high-pressure steam-driven injection systems (RCIC/HPCI) and loss of the power conversion system (condenser/feedwater) and would require activating the RHR system. In addition, EOPs direct the operator to take control of the depressurization function if low pressure injection/spray systems are needed for RPV water makeup and cooling. Based on the low probability of loss of the necessary overpressure protection function and the number of systems available in Mode 3, the NRC staff concludes in the SE to the BWR topical report that the risks of staying in Mode 3 are approximately the same as, and in some cases lower than, the risks of going to the Mode 4 end state.

Based on the above assessment, and because the time spent in Mode 3 at higher pressure to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC staff finds the change acceptable.

3.2.5 STS LCO 3.6.1.6: Low-Low Set (LLS) Valves The Browns Ferry TSs do not include a specification for LLS valves.

3.2.6 LCO 3.6.1.5 (STS LCO 3.6.1.7): Reactor Building-to-Suppression Chamber Vacuum Breakers The reactor building-to-suppression chamber vacuum breakers relieve vacuum when the primary containment depressurizes below the pressure of the reactor building, thereby serving to preserve the integrity of the primary containment.

LCO: Each reactor building-to-suppression chamber vacuum breaker shall be operable.

Condition Requiring Entry into End State: If one line has one or more reactor building-to-suppression chamber vacuum breakers inoperable for opening, the breaker(s) must be returned to operability within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (Required Action C.1). If two lines with one or more reactor building-to suppression chamber vacuum breakers are inoperable for opening all vacuum breakers must be restored to operable within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months (Required Action D.1). If the vacuum breaker(s) cannot be returned to operability within the allotted time, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action E.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action E.2).

Modification for End State Required Actions: Modify the Required Actions so that if vacuum breaker(s) cannot be returned to operable status within the required CT, the plant is placed in hot shutdown. That is:

1. Insert a new Condition D that requires the plant be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months if the Required Actions for Condition C (one line with one or more vacuum breakers inoperable) are not met. This eliminates the requirement to proceed to Mode 4 if the Required Action for Condition C is not met. This is the only end state changed for this LCO.

2. Modify the old Condition D by renumbering it to Condition E.

3. Modify the old Condition E by renumbering to Condition F and revising it to require the plant be placed in Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months if the plant fails to comply with the required actions related to Conditions A, B, and E (previously D). The previous end state required by the LCO for these conditions is unchanged.

Assessment: The BWROG determined that the specific failure condition of interest is not risk significant in BWR PRAs (Reference 4). The revised end state would only be applicable to the situation where the vacuum breaker(s) in one line are inoperable for opening, with the remaining operable vacuum breakers capable of providing the necessary vacuum relief function. The existing end state remains unchanged, as established by new Condition F, for conditions involving more than one inoperable line or vacuum breaker since they are needed in Modes 1, 2, and 3. In Mode 3, for other accident considerations, HPCI, RCIC, and the power conversion system (condensate/ feedwater) remain available for water makeup and decay heat removal.

Additionally, the EOPs direct the operators to take control of the depressurization function if low pressure injection/spray systems are needed for reactor coolant makeup and cooling.

Therefore, defense-in-depth is maintained with respect to water makeup and decay heat removal by remaining in Mode 3.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC staff finds the change acceptable.

3.2.7 LCO 3.6.1.6 (STS LCO 3.6.1.8): Suppression Chamber-to-Drywell Vacuum Breakers The function of the suppression chamber-to-drywell vacuum breakers is to relieve vacuum in the drywell, thereby preventing an excessive negative differential pressure across the wetwell/drywell boundary.

LCO: Ten suppression chamber-to-drywell vacuum breakers shall be operable for opening.

Condition Requiring Entry into End State: If one suppression chamber-to-drywell vacuum breaker is inoperable for opening, the breaker must be returned to operability within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (Required Action A.1). If one suppression chamber-to-drywell vacuum breaker is not closed it must be closed within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months (Required Action B.1). If the vacuum breaker cannot be returned to operability within the allotted time, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action C.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action C.2).

Modification for End State Required Actions: Modify the Required Actions so that if vacuum breaker that is inoperable for opening cannot be returned to operable status within the required CT, the plant is placed in Mode 3 without being required to proceed to Mode 4. For the vacuum breaker that is not closed, the end state is unchanged, and the Unit must be taken to Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . To make the change a new Condition B is added which requires the plant to be taken to Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months if Required Action A.1 is not completed within its CT. The original Condition B is renumbered to C. Condition C is renumbered to D and made to apply only to (new) Condition C, with Required Actions D.1 and D.2, shutting down the plant to Mode 3 and then Mode 4 respectively, to address an inability to comply with the required actions related to new Condition C, to close the vacuum breaker.

Assessment: The BWROG determined that the specific failure of interest is not risk significant in BWR PRAs (Reference 4). The reduced end state would only be applicable to the situation where one suppression chamber-to-drywell vacuum breaker is inoperable for opening, with the remaining operable vacuum breakers capable of providing the necessary vacuum relief function, since they are required in Modes 1, 2, and 3. By remaining in Mode 3, HPCI, RCIC, and the power conversion system (condensate/feedwater) remain available for water makeup and decay heat removal. Additionally, the EOPs direct the operators to take control of the depressurization function if low pressure injection/spray systems are needed for RCS makeup and cooling.

Therefore, defense-in-depth is maintained with respect to water makeup and decay heat removal by remaining in Mode 3. The existing end state remains unchanged for conditions involving any suppression chamber-to-drywell vacuum breakers that are stuck open, as established by new Condition D.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC staff finds the change acceptable.

3.2.8 STS LCO 3.6.1.9: Main Steam Isolation Valve (MSIV) Leakage Control System (LCS)

The Browns Ferry TSs do not include a specification for MSIV LCS.

3.2.9 LCO 3.6.2.3: RHR Suppression Pool Cooling Some means must be provided to remove heat from the suppression pool so that the temperature inside the primary containment remains within design limits. This function is provided by four redundant RHR suppression pool cooling subsystems.

LCO: Four RHR suppression pool cooling subsystems shall be operable. (STS requires 2 RHR suppression pool cooling systems operable with one required to perform the required cooling function.) For Browns Ferry, any two of the four suppression pool cooling subsystems can provide the necessary cooling.

Condition Requiring Entry into End State: If one RHR suppression pool cooling subsystem is inoperable (Condition A), it must be restored to operable status within 30 days (Required Action A.1). If two RHR suppression pool cooling subsystems are inoperable (Condition B), one of them must be restored to operable status within 7 days or in accordance with the RICT (Required Action B.1). If three or more RHR suppression pool cooling subsystems are inoperable (Condition C), the required subsystems must be restored to operable status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (Required Action C.1). If the RHR suppression pool cooling subsystems cannot be restored to operable status within the allotted time (Condition D), the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action D.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action D.2).

Modification for End State Required Actions: Add new Condition C, Required Action and associated Completion Time of Condition A or B not met, with Required Action C.1, be in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . Condition C is renumbered to Condition D and revised to state that the required subsystems be restored to operable status. Condition D is renumbered to Condition E and modified to be applicable only when Condition D is not met. This maintains the existing end state requirement to enter Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months for three or more RHR suppression pool subsystems inoperable.

Assessment: The BWROG performed a comparative PRA evaluation of the core damage risks of operation in the current end state versus operation in the Mode 3 end state (Reference 4).

The results indicated that the core damage risks while operating in Mode 3 (assuming the individual failure conditions) are lower or comparable to the current end state. Two subsystems of the RHR suppression pool cooling system are sufficient to accomplish the required safety function. By remaining in Mode 3, HPCI, RCIC, and the power conversion system (condensate/feedwater) remain available for water makeup and decay heat removal.

Additionally, the EOPs direct the operators to take control of the depressurization function if low pressure injection/spray systems are needed for RCS makeup and cooling. Therefore, defense-in-depth is improved with respect to water makeup and decay heat removal by remaining in Mode 3.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC staff finds the change acceptable.

3.2.10 LCO 3.6.2.4: RHR Suppression Pool Spray Following a design-basis accident (DBA), the RHR suppression pool spray system removes heat from the suppression chamber airspace. A minimum of two RHR suppression pool spray subsystems are required to mitigate potential bypass leakage paths from drywell and maintain the primary containment peak pressure below the design limits.

LCO: Four RHR suppression pool spray subsystems shall be operable. (STS assumes two loops operable with one required to perform the required cooling function.) For Browns Ferry, any two of the four suppression pool spray subsystems can provide the necessary cooling.

Condition Requiring Entry into End State: If one RHR suppression pool spray subsystem is inoperable (Condition A), it must be restored to operable status within 30 days (Required Action A.1). If two RHR suppression pool spray subsystems are inoperable (Condition B), one of them must be restored to operable status within 7 days or in accordance with the RICT (Required Action B.1). If three or more RHR suppression pool spray subsystems are inoperable (Condition C) they must be restored to operable within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (Required Action C.1). If the RHR suppression pool spray subsystem(s) cannot be restored to operable status within the allotted time (Condition D), the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action D.1), and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action D.2).

Modification for End State Required Actions: Delete Required Action D.2. This allows the plant to stay in Mode 3 instead of transitioning to Mode 4.

Assessment: The main function of the RHR suppression spray system is to remove heat from the suppression chamber so that the pressure and temperature inside primary containment remain within analyzed design limits. The RHR suppression spray system was designed to mitigate potential effects of a postulated DBA, that is, a large-break LOCA which is assumed to occur concurrently with the most limiting single failure. The analysis used conservative inputs, such as for initial suppression pool water volume and temperature. Under the conditions assumed in the DBA, steam blown down from the break could bypass the suppression pool and end up in the suppression chamber air space and the RHR suppression spray system could be needed to condense the steam so that the pressure and temperature inside primary containment remain within analyzed design basis limits. However, the frequency of a DBA is very small, and the containment has considerable margin to failure above the design limits. For these reasons, the unavailability of up to all of the RHR suppression spray subsystems has no significant impact on CDF or LERF, even for accidents initiated during operation at power.

Therefore, it is very unlikely that the RHR suppression spray system will be challenged to mitigate an accident occurring during power operation. This probability becomes extremely unlikely for accidents that would occur during a small fraction of the year during which the plant would be in Mode 3 (associated with lower initial energy level and reduced decay heat load as compared to power operation) to repair the failed RHR suppression spray system.

Section 6 of Reference 7 provides the details of the NRC staffs assessment for approval of Topical Report Section (TRS) 4.5.1.11 and the change to LCO 3.6.2.4, Residual Heat Removal (RHR) Suppression Pool Spray. Section 5 of the Topical Report SE provides the general risk argument for staying in Mode 3 instead of going to Mode 4 to repair the RHR Suppression Pool Spray system (one or both trains). The change is also supported by defense-in-depth considerations. Section 5.2 of the SE makes a comparison between the Mode 3 and the Mode 4 end state, with respect to the means available to perform critical functions (i.e., functions contributing to the defense-in-depth philosophy) whose success is needed to prevent core damage and containment failure and mitigate radiation releases and precluding the need for RHR suppression spray subsystems.

In addition, the probability of a DBA (large-break LOCA) is much smaller during shutdown as compared to power operation. A DBA in Mode 3 would be considerably less severe than a DBA occurring during power operation since Mode 3 is associated with lower initial energy level and reduced decay heat load. Under these extremely unlikely conditions, an alternate method that can be used to remove heat from the primary containment (in order to keep the pressure and temperature within the analyzed design basis limits) is containment venting. For more realistic accidents that could occur in Mode 3, several alternate means are available to remove heat from the primary containment, such as the RHR system in the suppression pool cooling mode and the containment spray mode. The risk and defense-in-depth arguments, used according to the integrated decision-making process of RGs 1.174 and 1.177, support the conclusion that Mode 3 is as safe as, if not safer than, Mode 4 for repairing an inoperable RHR suppression spray system.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC staff finds the change acceptable.

3.2.11 LCO 3.6.4.1: Secondary Containment Following a DBA, the function of the secondary containment is to contain, dilute, and stop radioactivity (mostly fission products) that may leak from primary containment. Its leak tightness is required to ensure that the release of radioactivity from the primary containment is restricted to those leakage paths and associated leakage rates assumed in the accident analysis and that fission products entrapped within the secondary containment structure will be treated by the standby gas treatment (SGT) system prior to discharge to the environment.

LCO: The secondary containment shall be operable.

Condition Requiring Entry into End State: If the secondary containment is inoperable, it must be restored to operable status within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months (Required Action A.1). If it cannot be restored to operable status within the allotted time, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action B.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action B.2).

Modification for End State Required Actions: Delete Required Action B.2. This permits the plant to remain in Mode 3, instead of proceeding to Mode 4, to make repairs to establish secondary containment as operable.

Assessment: This LCO entry condition does not include gross leakage through an unisolable release path because the primary containment is reliable. To support this premise, the BWROG determined that previous generic PRA work related to Appendix J requirements has shown that containment leakage is not risk significant (Reference 4). The primary containment and all other primary and secondary containment-related functions would still be operable, including the SGT system, thereby minimizing the likelihood of an unacceptable release. By remaining in Mode 3, HPCI, RCIC, and the power conversion system (condensate/feedwater) remain available for water makeup and decay heat removal. Additionally, the EOPs direct the operators to take control of the depressurization function if low pressure injection/spray systems are needed for RCS makeup and cooling. Therefore, defense-in-depth is improved with respect to water makeup and decay heat removal by remaining in Mode 3.

The requested change is acceptable based on the discussion above. Note that the NRC staffs approval relies upon the primary containment operability while in this end state and also relies on other secondary containment functions to be operable, including standby gas treatment. If primary containment is inoperable, the plant must be taken to Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months per LCO 3.6.1.1 (TS 3.6.1.1, Primary Containment).

3.2.12 LCO 3.6.4.3: SGT System The function of the SGT system is to ensure that radioactive materials that leak from the primary containment into the secondary containment following a DBA are filtered and adsorbed prior to exhausting the effluent to the environment.

LCO: Three SGT subsystems shall be operable. (STS requires two SGT subsystems operable.)

In addition, the STS include an applicability for during movement of [recently] irradiated fuel assemblies in [secondary] containment. Browns Ferry does not have this applicability.

Condition Requiring Entry into End State: If one SGT subsystem is inoperable, it must be restored to operable status within 7 days (Required Action A.1). If the SGT subsystem cannot be restored to operable status within the allotted time, the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action B.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action B.2). In addition, if two or three SGT subsystems are inoperable in Modes 1, 2, or 3, LCO 3.0.3 must be entered immediately (Required Action C.1).

Modification for End State Required Actions: Delete Required Action B.2. This results in the end state for one SGT subsystem inoperable to Mode 3 from Mode 4. Change Required Action C.1 to Be in Mode 3 with a Completion Time of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This changes the end state for two or three SGT subsystems inoperable from Enter LCO 3.0.3 (essentially Mode 4) to Mode 3.

Assessment: The unavailability of one, two, or three SGT subsystems has no impact on CDF or LERF, irrespective of the mode of operation at the time of the assumed accident. Furthermore, the challenge frequency of the SGT system (i.e., the frequency with which the system is expected to be challenged to mitigate offsite radiation releases resulting from materials that leak from the primary to the secondary containment above TS limits) is less than 1.0x10-6/yr.

Consequently, the conditional probability that this system will be challenged during the repair time interval while the plant is in the end state is less than 1.0x10-8. This probability is considerably smaller than probabilities considered negligible in RG 1.177 for much higher consequence risks, such as large early release.

Section 6 of Reference 7 provides the details of the NRC staffs assessment for approval of TRS 4.5.1.13, TRS 4.5.2.11, and LCO 3.6.4.3, Standby Gas Treatment (SGT) System.

Section 5 of the Topical Report SE provides the general risk argument for staying in Mode 3 instead of going to Mode 4 to repair the SGT subsystem(s). The argument for staying in Mode 3 instead of going to Mode 4 to repair the SGT system (one, two, or three trains) is also supported by defense-in-depth considerations. Section 5.2 of the SE makes a comparison between the Mode 3 and the Mode 4 end state, with respect to the means available to perform critical functions (i.e., functions contributing to the defense-in-depth philosophy) whose success is needed to prevent core damage and containment failure and mitigate radiation releases. The risk and defense-in-depth arguments, used according to the integrated decision-making process of RGs 1.174 and 1.177, support the conclusion that Mode 3 is as safe as, if not safer than, Mode 4 for repairing an inoperable SGT system.

Based upon the above assessment, the very low risk of having the SGT system inoperable, because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations (discussed in Reference 4), the NRC staff finds the change acceptable.

3.2.13 LCO 3.7.1: Residual Heat Removal Service Water (RHRSW) System The RHRSW system is designed to provide cooling water for the RHR system heat exchangers, which are required for safe shutdown following a normal shutdown or DBA or transient.

LCO: For Browns Ferry, the number of RHRSW pumps required to be operable depends on the status of the units. For Browns Ferry, four RHRSW subsystems are required to be operable with the number of required pumps as listed below:

1 unit fueled - four OPERABLE RHRSW pumps, 2 units fueled - six OPERABLE RHRSW pumps, 3 units fueled - eight OPERABLE RHRSW pumps.

The Browns Ferry RHRSW system is common to the three units and consists of four independent and redundant subsystems. Two subsystems with one pump operating in each are capable of providing the cooling requirements to maintain safe shutdown for one unit.

The STS requires two RHRSW subsystems to be operable.

Condition Requiring Entry into End State: If the LCO cannot be met, the following actions must be taken for the listed Conditions:

A. If one required RHRSW pump is inoperable (Condition A), five RHRSW pumps powered from separate 4 kV shutdown boards must be verified operable immediately (Required Action A.1) or the inoperable pump must be restored to operable status within 30 days (Required Action A.2).

B. If one RHRSW subsystem is inoperable (Condition B) it must be restored to operable status within 30 days (Required Action B.1).

C. If two required RHRSW pumps are inoperable (Condition C), one pump must be restored to operable status within 7 days or per the RICT (Required Action C.1).

D. If two RHRSW subsystems are inoperable (Condition D), one RHRSW subsystem must be restored to operable status within 7 days or per the RICT (Required Action D.1).

E. If three or more required RHRSW pumps are inoperable (Condition E), one RHRSW pump must be restored to operable status in 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (Required Action E.1).

F. If three or more RHRSW subsystems are inoperable (Condition F), one RHRSW subsystem must be restored to operable status in 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

G. If the required actions and associated completion times cannot be met within the allotted time (Condition G), the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action G.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action G.2).

Modification for End State Required Actions: Conditions A, B, C, and D are unchanged. A new Condition E is inserted (after D) that states Required Action and associated Completion Time of Condition A, B, C, or D not met. A new Required Action E.1 is inserted to take the plant to Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . Renumber Conditions E (and Required Action E.1), and F (and Required Action F.1), to Conditions F (and Required Action F.1) and G (and Required Action G.1), respectively. Renumber existing Condition G (along with Required Actions G.1 and G.2) to Condition H (and Required Actions H.1 and H.2) and make the Condition H applicable only if Conditions F or G Required Actions are not completed within the Completion Time. The existing required actions (from G) are retained as H.1 and H.2 which require the plant to be taken to Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

This changes the end states allowing Conditions A, B, C, and D to remain in Mode 3 in accordance with new Condition E. The end state for renumbered Conditions F and G, imposed by renumbered Condition H, requires the plant to be taken to Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . For cases where the design flow is available from the operable subsystems, a Mode 3 end state is allowed. For cases where the number of subsystems or pumps may not provide the design cooling requirements, a Mode 4 end state is specified. The treatment for Browns Ferry is analogous to the TSTF treatment for the STS design.

Assessment: The BWROG performed a comparative PRA evaluation in TR NEDC-32988-A (Reference 4) of the core damage risks when operating in the current end state versus the Mode 3 end state. The results indicated that the core damage risks while operating in Mode 3 (assuming the individual failure conditions) are lower or comparable to the current end state. By remaining in Mode 3, HPCI, RCIC, and the power conversion system (condensate/feedwater) remain available for water makeup and decay heat removal. Additionally, the EOPs direct the operators to take control of the depressurization function if low pressure injection/spray systems are needed for RCS makeup and cooling. Therefore, defense-in-depth is improved with respect to water makeup and decay heat removal by remaining in Mode 3, and the required safety function can still be performed with the RHRSW subsystem components that are still operable.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.2.14 LCO 3.7.2: Emergency Equipment Cooling Water (EECW) System and Ultimate Heat Sink (UHS)

The EECW system (in conjunction with the UHS) is designed to provide cooling water for the removal of heat from certain safe shutdown-related equipment heat exchangers following a DBA or transient.

LCO: The EECW system with three pumps and UHS shall be operable.

The Browns Ferry EECW system and UHS are common to the three units. It has two independent loops that each have two pumps. Two EECW pumps are capable of providing the required cooling capacity.

The STS requires two plant service water (PSW) (different name than EECW) subsystems and the UHS to be operable.

Condition Requiring Entry into End State: If the LCO cannot be met, the following actions must be taken for the listed conditions:

A. If one EECW required pump is inoperable (Condition A), it must be restored to operable status within 7 days or per the RICT (Required Action A.1).

B. If Required Action A.1 is not completed in time, or two or more required EECW pumps are inoperable, or the UHS is inoperable (Condition B), the plant must be placed in Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months .

Modification: Condition B is modified so that it only addresses Condition A. Its required action is changed to delete the requirement to go to Mode 4. A new Condition C is added for two or more required EECW pumps inoperable or UHS inoperable. The required actions for Condition C are to be in Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in Mode 4 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . For cases where the design flow is available from the operable pumps, a Mode 3 end state is allowed. For cases where the number of pumps or the UHS may not provide the design cooling requirements, a Mode 4 end state is specified. The treatment for Browns Ferry is analogous to the TSTF treatment for the STS design.

Assessment: The BWROG topical report performed a comparative PRA evaluation of the core damage risks associated with operating in the current end state versus the Mode 3 end state.

The results indicated that the core damage risks while operating in Mode 3 (assuming the individual failure conditions) are lower or comparable to the current end state. With one required pump inoperable, the remaining pumps are adequate to perform the EECW heat removal function. By remaining in Mode 3, HPCI, RCIC, and the power conversion system (condensate/feedwater) remain available for water makeup and decay heat removal.

Additionally, the EOPs direct the operators to take control of the depressurization function if low pressure injection/spray systems are needed for RCS makeup and cooling. Therefore, defense-in-depth is improved with respect to water makeup and decay heat removal by remaining in Mode 3.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.2.14 LCO 3.7.3 (STS LCO 3.7.4): Control Room Emergency Ventilation System (CREVS)

The CREVS provides a radiologically controlled environment from which the plant can be safely operated following an uncontrolled release of radiation.

LCO: Two CREV subsystems shall be operable.

(The STS call this system the Main Control Room Environmental Control (MCREC) System.)

Condition Requiring Entry into End State: If the LCO cannot be met, the following actions must be taken for the listed conditions:

A. If one CREV subsystem is inoperable for reasons other than B, C, or D (Condition A),

the inoperable system must be restored to operable status within 7 days (Required Action A.1).

B. If one or more CREV subsystems is inoperable due to an inoperable [control room envelope] CRE boundary (Condition B), action must be taken to implement mitigating actions immediately (Required Action B.1), the mitigating actions must be verified adequate to protect the CRE occupants within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months (Required Action B.2), and the CRE boundary must be restored to operable within 90 days (Required Action B.3).

C. If two CREV subsystems are inoperable due to inoperable high efficiency particulate air (HEPA) filter or charcoal adsorbers which do not impact the ability of the CREV subsystems to meet flowrate requirements (Condition C), the HEPA filter and one charcoal adsorber must be restored to operable status within 7 days (Required Action C.1).

D. If one CREV subsystem is inoperable due to an inoperable charcoal adsorber which does not impact the ability of the CREV subsystem to meet flowrate requirements (Condition D), the charcoal adsorber must be restored to operable status within 14 days (Required Action D.1).

E. If the required action and Completion Time of Condition A, B, C, or D is not met (Condition E), the plant is required to be placed in Mode 3 in 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action E.1) and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action E.2).

F. If two CREV subsystems are inoperable for reasons other than Conditions B or C (Condition F), the plant is required to enter LCO 3.0.3 (Required Action F.1).

Modification for End State Required Actions: Delete Required Action E.2 and change Required Action F.1 to be in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This eliminates the requirement to enter Mode 4 when the CREVS is inoperable.

Assessment: The unavailability of one or both CREV subsystems has no significant impact on CDF or LERF, irrespective of the mode of operation at the time of the accident. Furthermore, the challenge frequency of the CREV system (i.e., the frequency with which the system is expected to be challenged to provide a radiologically controlled environment in the main control room following a DBA which leads to core damage and leaks of radiation from the containment that can reach the control room) is less than 1.0x10-6/yr. Consequently, the conditional probability that this system will be challenged during the repair time interval while the plant is at either the current or the proposed end state (i.e., Mode 4 or Mode 3, respectively) is less than 1.0x10-8. This probability is considerably smaller than probabilities considered negligible in RG 1.177 for much higher consequence risks, such as large early release.

Section 6 of the NRC SE on NEDC-32988 provides the details of the NRC staffs assessment for approval of TRS 4.5.1.16, and LCO 3.7.4, Control Room Emergency Ventilation (CREV)

System. The argument for staying in Mode 3 instead of going to Mode 4 to repair the CREVS (one or both trains) is also supported by defense-in-depth considerations. Section 5.2 of the SE makes a comparison between the Mode 3 and the Mode 4 end state, with respect to the means available to perform critical functions (i.e., functions contributing to the defense-in-depth philosophy) whose success is needed to prevent core damage and containment failure and mitigate radiation releases. The risk and defense-in-depth arguments, used according to the integrated decision-making process of RGs 1.174 and 1.177, support the conclusion that Mode 3 is as safe as Mode 4 (if not safer) for repairing an inoperable CREVS.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.2.15 LCO 3.7.4 (STS LCO 3.7.5): Control Room Air Conditioning (AC) System The control room air conditioning system provides temperature control for the control room following control room isolation. At Browns Ferry there is a Unit 1 and 2 control room AC system and a separate Unit 3 control room AC system.

LCO: Two control room air conditioning subsystems shall be operable. (The STS LCO for the Control Room AC System is 3.7.5.) Both Browns Ferry and the STS have applicability in Modes 1, 2, and 3, and during movement of irradiated fuel in the secondary containment.

Browns Ferry has an applicability for during core alterations which is not in the STS. The STS have applicability for conditions that could drain the reactor vessel while Browns Ferry does not.

This change only affects the conditions associated with Modes 1, 2, and 3.

Condition Requiring Entry into End State:

A. If one control room air conditioning subsystem is inoperable (Condition A), the subsystem must be restored to operable status within 30 days (Required Action A.1).

B. If two control room AC subsystems are inoperable (Condition B), the plant must initiate action to restore one AC subsystem to operable status immediately (Required Action B.1), and place an alternate cooling method in operation (Required Action B.2), and restore one AC subsystem to operable within 7 days (Required Action B.3).

C. If the required actions and associated completion times of Conditions A or B cannot be met (Condition C), the plant must be placed in Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Action C.1), and in Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action C.2).

Modification for End State Required Actions: Delete Required Action C.2. This eliminates the requirement to go to Mode 4 as an end state for this LCO. This is consistent with the TSTF end state.

Assessment: The unavailability of one or both air conditioning subsystems has no significant impact on CDF or LERF, irrespective of the mode of operation at the time of the accident.

Furthermore, the challenge frequency of the air conditioning system (i.e., the frequency with which the system is expected to be challenged to provide temperature control for the control room following control room isolation following a DBA) is less than 1.0x10-6/yr. Consequently, the conditional probability that this system will be challenged during the repair time interval while the plant is at either the current or the proposed end state (i.e., Mode 4 or Mode 3, respectively) is less than 1.0x10-8. This probability is considerably smaller than probabilities considered negligible in RG 1.177 for much higher consequence risks, such as large early release.

Section 6 of the NRC SE on NEDC-32988 provides the details of the NRC staffs assessment for approval of TRS 4.5.1.17, and LCO 3.7.5, Control Room Air Conditioning (AC) System.

The argument for staying in Mode 3 instead of going to Mode 4 to repair the air conditioning system (one or both trains) is also supported by defense-in-depth considerations. Section 5.2 of the SE makes a comparison between the Mode 3 and the Mode 4 end state, with respect to the means available to perform critical functions (i.e., functions contributing to the defense-in-depth philosophy) whose success is needed to prevent core damage and containment failure and mitigate radiation releases. The risk and defense-in-depth arguments, used according to the integrated decision-making process of RGs 1.174 and 1.177, support the conclusion that Mode 3 is as safe as, if not safer than, Mode 4 for repairing an inoperable air conditioning system.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.2.16 LCO 3.7.6: Main Condenser Off Gas (MCOG)

The Browns Ferry TSs do not include a specification for the MCOG system.

3.2.17 LCO 3.8.1: AC Sources (Operating)

The purpose of the alternating current (AC) electrical system is to provide, during all situations, the power required to put and maintain the plant in a safe condition and prevent the release of radioactivity to the environment.

The Class 1E electrical power distribution system AC sources consist of the offsite power source (preferred power sources, normal and alternate(s)) and the onsite standby power sources (e.g., emergency diesel generators (EDGs)). Units 1 and 2 have 4 shared EDGs and Unit 3 has 4 EDGs. As required by General Design Criterion (GDC) 17 of 10 CFR Part 50, Appendix A, the design of the AC electrical system provides independence and redundancy.

The onsite Class 1E AC distribution system is divided into redundant divisions so that the loss of any one division does not prevent the minimum safety functions from being performed. Each division (power board for Browns Ferry) has connections to two preferred offsite power sources and a single EDG or other Class 1E Standby AC power source.

Offsite power is supplied to the unit switchyard(s) from the transmission network by two transmission lines. From the switchyard(s), two electrically and physically separated circuits provide AC power through stepdown transformers to the 4.16-kV emergency buses. In the event of a loss of offsite power, the emergency electrical loads are automatically connected to the EDGs in sufficient time to provide for a safe reactor shutdown and to mitigate the consequence of a DBA such as a LOCA.

LCO: The following AC electrical power sources shall be operable in Modes 1, 2, and 3:

a. Two qualified circuits between the offsite transmission network and the onsite Class1E AC Electric Power Distribution System;

b. Unit 1 and 2 diesel generators (DGs) with two divisions of 480 V load shed logic and common accident signal logic operable; and

c. Unit 3 DG(s) capable of supplying the Unit 3 4.16kV shutdown board(s) required by LCO 3.8.7, Distribution System - Operating..

Condition requiring entry into end state: Plant operators must bring the plant to Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months following the sustained inoperability of: (1) one required offsite circuit; (2) one required DG; (3) one division of 480 V load shed logic; (4) one division of common accident signal logic; (5) two required offsite circuits; (6) one required offsite circuit and one DG; or (7) two or more DGs.

Modification for end state required actions: Delete required action I.2 to go to Mode 4 (cold shutdown). The plant will remain in Mode 3 (hot shutdown).

Assessment: Entry into any of the conditions for the AC power sources implies that the AC power sources have been degraded and the single failure protection for the safe shutdown equipment may be ineffective. Consequently, as specified in TS 3.8.1 at present, the plant operators must bring the plant to Mode 4 when the required action is not completed by the specified time for the associated action.

The BWROG did a comparative PRA evaluation of the core damage risks of operation in the current end state and in the Mode 3 end state (Reference 4). Events initiated by the loss of offsite power are dominant contributors to CDF in most BWR PRAs, and the steam-driven core cooling systems (RCIC and HPCI) play a major role in mitigating these events. The evaluation indicates that the core damage risks are lower in Mode 3 than in Mode 4 for one inoperable AC power source. Going to Mode 4 for one inoperable AC power source would cause loss of the high-pressure steam-driven injection system (RCIC/HPCI), and loss of the power conversion system (condenser/feedwater), and require activating the RHR system. In addition, EOPs direct the operator to take control of the depressurization function if low pressure injection/spray systems are needed for RPV water makeup and cooling. Based on the low probability of loss of the AC power and the number of steam-driven systems available in Mode 3, the NRC staff concludes in the SE to the BWR topical report that the risks of staying in Mode 3 are lower than going to the Mode 4 end state.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.2.18 LCO 3.8.4: DC Sources (Operating)

The purpose of the direct current (DC) power system is to provide a reliable source of DC power for both normal and abnormal conditions. It must supply power in an emergency for an adequate length of time until normal supplies can be restored. The DC electrical system:

a. Provides the AC emergency power system with control power;

b. Provides motive and control power to selected safety related equipment; and

c. Provides power to preferred AC vital buses (via inverters).

LCO: For Modes 1, 2, and 3, the following DC sources are required to be operable:

a. Unit DC subsystems 1, 2, and 3;

b. Shutdown Board DC subsystems A, B, C, and D;

c. Unit 1 and 2 Diesel Generator (DG) DC subsystems;

d. Unit 3 DG DC subsystem(s) supporting DG(s) required to be OPERABLE by LCO 3.8.1, AC Sources - Operating; and

e. Unit 3 Shutdown Board DC subsystem 3EB needed to support equipment required to be operable by LCO 3.7.3, Control Room Emergency Ventilation (CREV) System.

Condition requiring entry into end state: The plant operators must bring the plant to Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months following the inoperability of one DC electrical power subsystem or the inoperability of one Unit 1 and 2 Shutdown Board DC electrical power system for a period of 7 days or per the RICT.

Modification for end state required actions: Delete Required Action B.2 to go to Mode 4 (cold shutdown). The plant will remain in Mode 3 (hot shutdown).

Assessment: If one of the DC electrical power subsystems is inoperable, the remaining DC electrical power subsystems have the capacity to support a safe shutdown and to mitigate an accident condition. The BWROG did a comparative PRA evaluation of the core damage risks of operation in the current end state and in the Mode 3 end state, with one DC system inoperable (Reference 4). Events initiated by the loss of offsite power are dominant contributors to CDF in most BWR PRAs, and the steam-driven core cooling systems (RCIC and HPCI) play a major role in mitigating these events. The evaluation indicates that the core damage risks are lower in Mode 3 than in Mode 4. Going to Mode 4 for one inoperable DC power source would cause loss of the high-pressure steam-driven injection system (RCIC/HPCI), and loss of the power conversion system (condenser/feedwater), and require activating the RHR system. In addition, EOPs direct the operator to take control of the depressurization function if low pressure injection/spray systems are needed for RPV water makeup and cooling. Based on the low probability of loss of the DC power and the number of systems available in Mode 3, the NRC staff concludes in the SE to the BWR topical report that the risks of staying in Mode 3 are approximately the same as, and in some cases lower than, the risks of going to the Mode 4 end state.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.2.19 STS LCO 3.8.7: Inverters (Operating)

The Browns Ferry TSs do not have a specification for Inverters during operation.

3.2.20 LCO 3.8.7 (STS LCO 3.8.9): Distribution Systems (Operating)

The onsite Class 1E AC and DC electrical power distribution system is divided into redundant and independent AC and DC electrical power distribution systems. The primary AC electrical power distribution subsystem consists of four Unit 1 and Unit 2 4.16 kV shutdown boards, each having an offsite source of power, as well as a dedicated onsite DG source. The secondary plant distribution system includes 480 VAC shutdown boards and associated load centers and transformers. There are three unit DC and associated 250 VDC (reactor motor-operated valve)

RMOV boards and five Shutdown Board 250 VDC electrical power distribution systems. There is one 125 VDC DG electrical power distribution subsystem for each DG that supports the necessary power for engineered safety feature functions.

LCO: For Modes 1, 2, and 3, the following electrical power distribution subsystems shall be operable:

a. Unit 1 and 2 (Unit 3) 4.16 kV Shutdown Boards;

b. Unit 1 (Unit 2) (Unit 3) 480 V Shutdown Boards;

c. Unit 1 480 V RMOV Boards 1A and 1B (Unit 2 480 V RMOV Boards 2A, 2B, 2D, and 2E)

(Unit 3 480 V RMOV Boards 3A, 3B, 3D, and 3E);

d. Unit 1 and 2 DG Auxiliary Boards;

e. Unit DC Boards and 250 V DC RMOV Boards 1A, 1B, and 1C (Unit 2: RMOV Boards 2A, 2B, and 2C) (Unit 3: RMOV Boards 3A, 3B, and 3C);

f.

Unit 1 and 2 Shutdown Board DC Distribution Panels (Unit 3: Shutdown Board DC Distribution Panel 3EB); and

g. Unit 2 and 3 AC and DC Boards needed to support equipment required to be operable by LCO 3.6.4.3, Standby Gas Treatment (SGT) System, and LCO 3.7.3, Control Room Emergency Ventilation (CREV) System. (Unit 2: Unit 1 and 3) (Unit 3: Unit 1 and 2)

This list of components required for operability and the description above are similar for Units 1, 2, and 3. The differences for Units 2 and 3 are shown in parentheses.

Condition requiring entry into end state: The plant operators must bring the plant to Mode 3 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and to Mode 4 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months following the sustained inoperability of one AC or one DC electrical power subsystem.

Modification for end state required actions: The TS change is to remove the requirement to place the plant in Mode 4, Required Action in G.2 for Unit 1, and H.2 for Units 2 and 3.

Condition H (Unit 1) and Condition I (Units 2 and 3) require immediate entry into 3.0.3 if more than one subsystem is inoperable resulting in a loss of function.

Assessment: If one of the AC, DC, or vital AC subsystems is inoperable, the remaining AC, DC, and vital AC subsystems have the capacity to support a safe shutdown and to mitigate an accident condition. The BWROG did a comparative PRA evaluation of the core damage risks of operation in the current end state and in the Mode 3 end state, with one of the AC/DC subsystems inoperable (Reference 4). Events initiated by the loss of offsite power are dominant contributors to CDF in most BWR PRAs, and the steam-driven core cooling systems (RCIC and HPCI) play a major role in mitigating these events. The evaluation indicates that the core damage risks are lower in Mode 3 than in Mode 4. Going to Mode 4 for one inoperable AC/DC/AC vital subsystem would cause loss of the high-pressure steam-driven injection system (RCIC/HPCI), and loss of the power conversion system (condenser/feedwater), and require activating the RHR system. In addition, EOPs direct the operator to take control of the depressurization function if low pressure injection/spray systems are needed for RPV water makeup and cooling. Based on the low probability of loss of the AC/DC/AC vital electrical subsystems during the infrequent and limited time in Mode 3 and the number of systems available in Mode 3, the NRC staff concludes in the SE to the BWR topical report that the risks of staying in Mode 3 are approximately the same as, and in some cases lower than, the risks of going to the Mode 4 end state.

Based upon the above assessment, and because the time spent in Mode 3 to perform the repair is infrequent and limited, and in light of defense-in-depth considerations, the NRC staff finds the change acceptable.

3.3 Technical Conclusion The NRC staff finds the proposed changes acceptable because the licensee has established end state actions that have been evaluated for their impact on plant risk and shown to result in similar or reduced risk to the plant. These end state actions are required when an LCO is not met and other actions allowed by the TS have not been successful in exiting the LCO.

Paragraph 50.36(c)(2)(i) of 10 CFR states When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shutdown the reactor or follow any remedial action permitted by the technical specifications. The NRC staff has determined that the proposed end states provide equivalent or reduced risk compared to the existing end states as described for each affected LCO. Therefore, the changes are acceptable because, as revised, they will continue to meet the requirements of 10 CFR 50.36.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Alabama State official was notified of the proposed issuance of the amendment on August 6, 2025. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission previously issued a proposed finding that the amendment involves no significant hazards consideration published in the Federal Register on June 10, 2025 (90 FR 24417), and there has been no public comment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

7.0 REFERENCES

1. Letter from Hulvey, K. D., Tennessee Valley Authority, to U.S. Nuclear Regulatory Commission, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - License Amendment Request for Adoption of Technical Specifications Task Force (TSTF) Traveler TSTF-423-A, Revision 1, Technical Specifications End States, NEDC-32988-A, Using the Consolidated Line Item Improvement Process (BFN-TS-548), April 10, 2025 (Agencywide Documents Access and Management System Accession No. ML25100A124).

2. Letter from Hulvey, K. D., Tennessee Valley Authority, to U.S. Nuclear Regulatory Commission, Browns Ferry Nuclear Plant, Units 1, 2, and 3 - Supplement to License Amendment Request for Adoption of Technical Specifications Task Force (TSTF) Traveler TSTF-423-A, Revision 1 (EPID L-2025-LLA-0070), July 14, 2025 (ML25195A060).

3. TSTF-423, Revision 1, Technical Specifications End States, NEDC-32988-A, dated December 22, 2009 (ML093570241).

4. NEDC-32988-A, Revision 2, Technical Justification to Support Risk-Informed Modification to Selected Required Action End States for BWR Plants, December 2002 (ML030170090).

5. Regulatory Guide 1.160, Revision 4, Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, USNRC, August 2018 (ML18220B281).

6. NUMARC 93-01, Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, Nuclear Energy Institute, Revision 4F, April 2018 (ML18120A069).

7. NRC Safety Evaluation for Topical Report NEDC-32988, Revision 2, September 27, 2002 (ML022700603).

8. TSTF-IG-05-02, Revision 2, Implementation Guidance for TSTF-423, Revision 1, Technical Specifications End States, NEDC-32988-A, November 2009 (ML093570241).

9. Regulatory Guide 1.174, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, USNRC, July 1998 (ML003740133).

10. Regulatory Guide 1.177, An Approach for Plant Specific, Risk-Informed Decisionmaking:

Technical Specifications, USNRC, August 1998 (ML003740176).

Principal Contributors: S. Smith, NRR A. Stubbs, NRR E. Kleeh, NRR Date: December 18, 2025

ML25337A128 NRR-058 OFFICE NRR/DORL/LPLII-2/PM NRR/DORL/LPLII-2/LA NRR/DSS/SCPB/BC NRR/DEX/EEEB/BC NAME KGreen ABaxter MValentin WMorton (DMurdock for)

DATE 12/03/2025 12/15/2025 09/25/2025 12/16/2025 OFFICE NRR/DSS/STSB/BC NRR/DORL/LPLII-2/BC NRR/DORL/LPLII-2/PM NAME SMehta DWrona KGreen DATE 09/25/2025 12/18/2025 12/18/2025

v t e Letter Sequence Approval
EPID:L-2025-LLA-0070, TSTF-423 (Open)
Initiation Request Acceptance Administration Questions Answers Results Approval, Approval Other:
MONTHYEAR2025-12-18 [Table View]

ML25337A128

Text

SUBJECT:

Dear Mr. Erb:

Enclosures:

1.0 INTRODUCTION

2.0 REGULATORY EVALUATION

3.0 TECHNICAL EVALUATION

4.0 STATE CONSULTATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 CONCLUSION

7.0 REFERENCES

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