Text

Issuance of Amendment Nos. 130 and 33 Regarding Adoption of Technical Specifications Task Force Traveler, TSTF-500, DC Electrical Rewrite - Update to TSTF-360
	ML19276E557
Person / Time
Site:	Watts Bar
Issue date:	12/09/2019
From:	Michael Wentzel; Plant Licensing Branch II
To:	Jim Barstow; Tennessee Valley Authority
	Wentzel, Michael
References
	EPID L-2018-LLA-0494
	Download: ML19276E557 (104)
	v • d • e

UNITED STATES WASHINGTON, D.C. 20555-0001 December 9, 2019 Mr. James Barstow Vice President, Nuclear Regulatory Affairs and Support Services Tennessee Valley Authority 1101 Market Street, LP 4A-C Chattanooga, TN 37402-2801

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNITS 1 AND 2- ISSUANCE OF AMENDMENT NOS. 130 AND 33 REGARDING ADOPTION OF TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER TSTF-500, "DC ELECTRICAL REWRITE- UPDATE TO TSTF-360" (EPID L-2018-LLA-0494)

Dear Mr. Barstow:

The U.S. Nuclear Regulatory Commission (NRC or the Commission) has issued the enclosed Amendment Nos.130 and 33 to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant, Units 1 and 2, respectively. These amendments are in response to the application from the Tennessee Valley Authority dated November 29, 2018, as supplemented by letters dated June 7, 2019; September 4, 2019; and October 10, 2019.

These amendments revise the technical specification requirements for Watts Bar Nuclear Plant, Units 1 and 2, in accordance with the NRG-approved Technical Specifications Task Force (TSTF) Traveler, TSTF 500, Revision 2, "DC [Direct Current] Electrical Rewrite - Update to TSTF 360." In addition, the amendments revise Technical Specification 3.8.4, "DC Sources -

Operating," to declare the associated diesel generator(s) inoperable when one or more diesel generator direct current battery charger(s) in redundant trains is inoperable.

A copy of the related safety evaluation is also enclosed. Notice of issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely, ti U

GUV\ // 'I Michael J. Wentzel,~*oject Manager Plant Licensing Bra~c 11-2 Division of Operatin eactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-390 and 50-391

Enclosures:

1. Amendment No. 130 to NPF-90

2. Amendment No. 33 to NPF-96

3. Safety Evaluation cc: Listserv

UNITED STATES WASHINGTON, D.C. 20555-0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-390 WATTS BAR NUCLEAR PLANT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 130 License No. NPF-90

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

A. The application for amendment by Tennessee Valley Authority {TVA, the licensee) dated November 29, 2018, as supplemented by letters dated June 7, 2019; September 4, 2019; and October 10, 2019, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 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 Commission's 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 Commission's regulations and all applicable requirements have been satisfied.

Enclosure 1

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 Facility Operating License No. NPF-90 is hereby amended to read as follows:

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 130 and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3. This license amendment is effective as of the date of its issuance and shall be implemented within 60 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Undine Shoop, Chief Plant Licensing Branch 11-2 Division of operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Facility Operating License and Technical Specifications Date of Issuance: December 9, 2 O1 9

ATTACHMENT TO AMENDMENT NO. 130 WATTS BAR NUCLEAR PLANT, UNIT 1 FACILITY OPERATING LICENSE NO. NPF-90 DOCKET NO. 50-390 Replace page 3 of Facility Operating License No. NPF-90 with the attached revised page 3.

Replace the following pages of the Appendix A Technical Specifications with the attached pages. The revised pages are identified by amendment number and contain vertical lines indicating the area of change.

Remove Insert 3.8-24 3.8-24 3.8-25 3.8-25 3.8-26 3.8-26 3.8-27 3.8-27 3.8-28 3.8-28 3.8-29 3.8-29 3.8-30 3.8-30 3.8-31 3.8-31 3.8-32 3.8-32 3.8-33 3.8-33 3.8-34 3.8-34 3.8-34a 3.8-34b 3.8-35 3.8-35 3.8-36 3.8-36 5.0-25b

(4) TVA, 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, instrument calibration, or other activity associated with radioactive apparatus or components; and (5) TVA, pursuant to the Act and 10 CFR Parts 30, 40 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 license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter I and 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 TVA is authorized to operate the facility at reactor core power levels not in excess of 3459 megawatts thermal.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 130 and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

(3) Safety Parameter Display System (SPDS) (Section 18.2 of SER Supplements 5 and 15)

Prior to startup following the first refueling outage, TVA shall accomplish the necessary activities, provide acceptable responses, and implement all proposed corrective actions related to having the Watts Bar Unit 1 SPDS operational.

(4) Vehicle Bomb Control Program {Section 13.6.9 of SSER 20)

During the period of the exemption granted in paragraph 2.D.(3) of this license, in implementing the power ascension phase of the approved initial test program, TVA shall not exceed 50% power until the requirements of 10 CFR 73.55(c)(7) and (8) are fully implemented. TVA shall submit a letter under oath or affirmation when the requirements of

. 73.55(c)(7) and (8) have been fully implemented.

Facility License No. ~PF-90 Amendment No. 130

DC Sources - Operating 3.8.4 3.8 ELECTRICAL POWER SYSTEMS 3.8.4 DC Sources - Operating LCO 3.8.4 The Train A and Train B vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE.

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

Vital Battery V may be substituted for any of the required vital batteries.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or two required vital A.1 Restore battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery charger(s) on one voltage to greater than or subsystem inoperable. equal to the minimum established float voltage.

AND A.2 Verify battery float current Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months s; 2 amps.

AND A.3 Restore vital battery charger(s) 7 days to OPERABLE status.

B. One vital DC electrical 8.1 Restore vital DC electrical 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months power subsystem power subsystem to inoperable for reasons OPERABLE status.

other than Condition A.

C. Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Associated Completion Time of Condition A or B AND not met.

C.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (continued)

Watts Bar-Unit 1 3.8-24 Amendment 130

DC Sources - Operating 3.8.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. One or two DG DC battery D.1 Restore DG battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months charger(s) on one train voltage to greater than or inoperable. equal to the minimum established float voltage.

AND D.2 Verify battery float current Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months s; 1 amp.

AND D.3 Restore DG DC battery 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months charger(s) to OPERABLE status.

E. One DG DC train E.1 Restore DG DC train to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable for reasons OPERABLE status.

other than Condition D.

F. Required Action and F.1 Declare associated DG(s) Immediately associated Completion inoperable.

Time of Condition Dor E not met.

OR One or more DG DC battery charger(s) in redundant trains inoperable.

Watts Bar-Unit 1 3.8-25 Amendment 130

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify vital battery terminal voltage is greater than 7 days or equal to the minimum established float voltage.

SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 days equal to the minimum established float voltage.

SR 3.8.4.3 Verify for the vital batteries that the alternate feeder 7 days breakers to each required battery charger are open.

SR 3.8.4.4 Verify correct breaker alignment and indicated power 7 days availability for each DG 125 V DC distribution panel and associated battery charger.

SR 3.8.4.5 Verify each vital battery charger supplies .:: 200 amps 18 months at greater than or equal to the minimum established float voltage for .:: 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

Verify each vital battery charger can recharge the battery to the fully charged state within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months while supplying the largest combined demands of the various continuous steady state loads, after a battery discharge to the bounding design basis event discharge state.

(continued)

Watts Bar-Unit 1 3.8-26 Amendment 130

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.6 --------------NOTE------------

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG battery charger can recharge the 18 months battery to the fully charged state within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months while supplying the largest combined demands of the various continuous steady state loads, after a battery discharge to the bounding design basis event discharge state.

SR 3.8.4.7 ---------------NOTES-------------

1. The modified performance discharge test in SR 3.8.6.7 may be performed in lieu of the service test in SR 3.8.4.7.

2. This Surveillance is not performed in MODE 1, 2, 3, or 4 for required vital batteries.

Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is adequate to supply, and 18 months maintain in OPERABLE status, the required emergency loads and any connected nonsafety loads for the design duty cycle when subjected to a battery service test.

Watts Bar-Unit 1 3.8-27 Amendment 54, 130

DC Sources - Operating 3.8.4 This page intentionally left blank.

Watts Bar-Unit 1 3.8-28 Amendment 12, 130

DC Sources - Operating 3.8.4 This page intentionally left blank.

Watts Bar-Unit 1 3.8-29 Amendment 12, 130

DC Sources - Shutdown 3.8.5 3.8 ELECTRICAL POWER SYSTEMS 3.8.5 DC Sources - Shutdown LCO 3.8.5 Vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems - Shutdown" and to support the Diesel Generators (DGs) required by LCO 3.8.2, "AC Sources - Shutdown."

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

Vital Battery V may be substituted for any of the required vital batteries.

APPLICABILITY: MODES 5 and 6, During movement of irradiated fuel assemblies.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or two required vital A.1 Restore battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery charger(s) on one voltage to greater than or subsystem inoperable. equal to the minimum established float voltage.

AND AND The redundant subsystem vital battery and charger(s) A.2 Verify battery float current Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months OPERABLE. :,; 2 amps.

AND A.3 Restore battery charger(s) to 7 days OPERABLE status.

(continued)

Watts Bar-Unit 1 3.8-30 Amendment 130

DC Sources-Shutdown 3.8.5 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. One or more required vital B.1.1 Declare affected required Immediately DC electrical power feature(s) inoperable.

subsystems inoperable for reasons other than OR Condition A.

B.2.1 Suspend CORE Immediately OR ALTERATIONS.

Required Actions and AND associated Completion Time of Condition A not B.2.2 Suspend movement of Immediately met. irradiated fuel assemblies.

AND B.2.3 Initiate action to suspend Immediately operations involving positive reactivity additions.

AND B.2.4 Initiate action to restore Immediately required DC electrical power subsystems to OPERABLE status.

C. One required DG DC C.1 Declare associated DG Immediately electrical power subsystem inoperable.

inoperable.

Watts Bar-Unit 1 3.8-31 Amendment 130

DC Sources-Shutdown 3.8.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.5.1 --------------------------------NO TE-----------------------------

Th e following SRs are not required to be performed:

SR 3.8.4.5, SR 3.8.4.6, and SR 3.8.4.7.

For DC sources required to be OPERABLE, the In accordance with following SRs are applicable: applicable SRs SR 3.8.4.1 SR 3.8.4.5 SR 3.8.4.2 SR 3.8.4.6 SR 3.8.4.3 SR 3.8.4.7 SR 3.8.4.4 Watts Bar-Unit 1 3.8-32 Amendment 130

Battery Parameters 3.8.6 3.8 ELECTRICAL POWER SYSTEMS 3.8.6 Battery Parameters LCO 3.8.6 Battery parameters for Train A and Train B electrical power subsystem 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within limits.

APPLICABILITY: When associated DC electrical power subsystems and DGs are required to be OPERABLE.

ACTIONS

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

Separate Condition entry is allowed for each battery bank.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or two required vital A.1 Perform SR 3.8.4.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery(ies) on one subsystem with one or AND more battery cells float voltage< 2.07 V. A.2 Perform SR 3.8.6.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months AND A.3 Restore affected cell voltage 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

<! 2.07 V.

B. One or two required vital 8.1 Perform SR 3.8.4.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery(ies) on one subsystem with float AND current> 2 amps.

8.2 Restore vital battery float 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months current to ::; 2 amps.

(continued)

Watts Bar-Unit 1 3.8-33 Amendment 130

Battery Parameters 3.8.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. One or two DG battery(ies) C.1 Perform SR 3.8.4.2. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months on one train with one or more battery cells float AND voltage < 2.07 V.

C.2 Perform SR 3.8.6.2. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months AND C.3 Restore affected cell voltage 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 2! 2.07 V.

D. One or two DG battery(ies) D.1 Perform SR 3.8.4.2. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months on one train with float current > 1 amp. AND D.2 Restore vital battery float 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months current to s 1 amp.

NOTE-------------- ----------------NO TE----------------

Required Action E.2 shall be Required Actions E.1 and E.2 are only completed if electrolyte level was applicable if electrolyte level was below below the top of plates. the top of plates.

E. One or two required vital E.1 Restore electrolyte level to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months battery(ies) on one above top of plates.

subsystem with one or more cells electrolyte level AND less than minimum established design limits. E.2 Verify no evidence of leakage. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months OR AND One or two DG battery(ies) E.3 Restore electrolyte level to 31 days on one train with one or greater than or equal to more cells electrolyte level minimum established design less than minimum limits.

established design limits.

(continued)

Watts Bar-Unit 1 3.8-34 Amendment 130

Battery Parameters 3.8.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME F. One or two required vital F.1 Restore battery pilot cell 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months battery(ies) on one temperature to greater than or subsystem with pilot cell equal to minimum established electrolyte temperature design limits.

less than minimum established design limits.

OR One or two DG battery(ies) on one train with pilot cell electrolyte temperature less than minimum established design limits.

G. One or more vital batteries G.1 Restore battery parameters 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in redundant subsystems for vital batteries in one with battery parameters not subsystem to within limits.

within limits.

H. One or more DG batteries H.1 Restore battery parameters 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in redundant trains with for DG batteries in one train to battery parameters not within limits.

within limits.

(continued)

Watts Bar-Unit 1 3.8-34a Amendment 130

Battery Parameters 3.8.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME I. Required Action and 1.1 Declare associated battery Immediately associated Completion inoperable.

Time of Condition A, B, C, D, E, F, G, or H not met.

One or two required vital battery(ies) on one subsystem with one or more battery cells float voltage < 2.07 V and float current> 2 amps.

OR One or two DG battery(ies) on one train with one or more battery cells float voltage< 2.07 V and float current > 1 amp.

Watts Bar-Unit 1 3.8-34b Amendment 130

Battery Parameters 3.8.6 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 ----------------------NOTE------------------------

Not required to be met when vital battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.1.

Verify each vital battery float current is ~ 2 amps. 7 days SR 3.8.6.2 ----------------------NOTE-----------------------

Not required to be met when DG battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.2.

Verify each DG battery float current is~ 1 amp. 7 days SR 3.8.6.3 Verify each required vital battery and each DG 31 days battery pilot cell float voltage is~ 2.07 V.

SR 3.8.6.4 Verify each required vital battery and each DG 31 days battery connected cell electrolyte level is greater than or equal to minimum established design limits.

SR 3.8.6.5 Verify each required vital battery and each DG 31 days battery pilot cell temperature is greater than or equal to minimum established design limits.

SR 3.8.6.6 Verify each required vital battery and each DG 92 days battery connected cell float voltage is ~ 2.07 V.

(continued)

Watts Bar-Unit 1 3.8-35 Amendment 130

Battery Cell Parameters 3.8.6 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.6.7 -------------------NOTES-----------------------

This Surveillance is not performed in MODE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is~ 80% of the manufacturer's 60 months rating when subjected to a performance discharge test or a modified performance discharge test. AND 12 months when battery shows degradation or has reached 85% of expected life with capacity < 100% of manufacturer's rating 24 months when battery has reached 85% of the expected life with capacity

~ 100% of manufacturer's rating Watts Bar-Unit 1 3.8-36 Amendment 130

Procedures, Programs, and Manuals 5.7 5.7 Procedures, Programs, and Manuals 5.7.2.22 Battery Monitoring and Maintenance Program This Program provides controls for battery restoration and maintenance. The program shall be in accordance with IEEE Standard (Std) 450-2002, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," as endorsed by Regulatory Guide 1.129, Revision 2 (RG), with RG exceptions and program provisions as identified below:

a. The program allows the following RG 1.129, Revision 2 exceptions:

1. Battery temperature correction may be performed before or after conducting discharge tests.

2. RG 1.129, Regulatory Position 1, Subsection 2, "References," is not applicable to this program.

3. In lieu of RG 1.129, Regulatory Position 2, Subsection 5.2, "Inspections," the following shall be used: "Where reference is made to the pilot cell, pilot cell selection shall be based on the lowest voltage cell in the battery."

4. In Regulatory Guide 1.129, Regulatory Position 3, Subsection 5.4.1, "State of Charge Indicator," the following statements in paragraph (d) may be omitted:

"When it has been recorded that the charging current has stabilized at the charging voltage for three consecutive hourly measurements, the battery is near full charge. These measurements shall be made after the initially high charging current decreases sharply and the battery voltage rises to approach the charger output voltage."

5. In lieu of RG 1.129, Regulatory Position 7, Subsection 7.6, "Restoration", the following may be used: "Following the test, record the float voltage of each cell of the string."

b. The program shall include the following provisions:

1. Actions to restore battery cells with float voltage < 2.13 V;

2. Actions to determine whether the float voltage of the remaining battery cells is

.:: 2.13 V when the float voltage of a battery cell has been found to be

< 2.13 V;

3. Actions to equalize and test battery cells that had been discovered with electrolyte level below the top of the plates;

4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and

5. A requirement to obtain specific gravity readings of all cells at each discharge test, consistent with manufacturer recommendations.

Watts Bar-Unit 1 5.0-25b Amendment 130

UNITED STATES WASHINGTON, D.C. 20555-0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-391 WATTS BAR NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 33 License No. NPF-96

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

A. The application for amendment by Tennessee Valley Authority (TVA, the licensee) dated November 29, 2018, as supplemented by letters dated June 7, 2019; September 4, 2019; and October 10, 2019, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 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 Commission's 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 Commission's regulations and all applicable requirements have been satisfied.

Enclosure 2

2. Accordingly, Facility Operating License No. NPF-96 is amended as indicated in the attachment to this license amendment, and paragraph 2.C.(2) is hereby amended to read as follows:

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 33 and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan ..

3. This license amendment is effective as of the date of its issuance and shall be implemented within 60 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Undine Shoop, Chief Plant Licensing Branch 11-2 Division of operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Facility Operating License and Technical Specifications Date of Issuance: December 9, 2 O1 9

ATTACHMENT TO AMENDMENT NO. 33 WATTS BAR NUCLEAR PLANT, UNIT 2 FACILITY OPERATING LICENSE NO. NPF-96 DOCKET NO. 50-391 Replace page 3 of Facility Operating License No. NPF-96 with the attached revised page 3.

Replace the following pages of the Appendix A Technical Specifications with the attached pages. The revised pages are identified by amendment number and contain vertical lines indicating the area of change.

Remove Insert 3.8-21 3.8-21 3.8-22 3.8-22 3.8-23 3.8-23 3.8-24 3.8-24 3.8-25 3.8-25 3.8-26 3.8-26 3.8-27 3.8-27 3.8-28 3.8-28 3.8-29 3.8-29 3.8-30 3.8-30 3.8-30a 3.8-30b 3.8-31 3.8-31 3.8-32 3.8-32 5.0-27a 5.0-27b

C. The license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter I and 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 TVA is authorized to operate the facility at reactor core power levels not in excess of 3411 megawatts thermal.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 33 and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

(3) TVA shall implement permanent modifications to prevent overtopping of the embankments of the Fort Loudon Dam due to the Probable Maximum Flood by June 30, 2018.

(4) PAD4TCD may be used to establish core operating limits until the WBN Unit 2 steam generators are replaced with steam generators equivalent to the existing steam generators at WBN Unit 1.

(5) By December 31, 2019, the licensee shall report to the NRC that the actions to resolve the issues identified in Bulletin 2012-01, "Design Vulnerability in Electrical Power System," have been implemented.

(6) The licensee shall maintain in effect the provisions of the physical security plan, security personnel training and qualification plan, and safeguards contingency plan, and all amendments made pursuant to the authority of 10 CFR 50.90 and 50.54(p ).

(7) TVA shall fully implement and maintain in effect all provisions of the Commission approved cyber security plan (CSP), including changes made pursuant to the authority of 10 CFR 50.90 and 10 CFR 50.54(p). The TVA approved CSP was discussed in NUREG-0847, Supplement 28, as amended by changes approved in License Amendment No. 7.

(8) TVA shall implement and maintain in effect all provisions of the approved fire protection program as described in the Fire Protection Report for the facility, as described in NUREG-0847, Supplement 29, subject to the following provision:

Unit 2 Facility Operating License No. NPF-96 Amendment No. 33

DC Sources - Operating 3.8.4 3.8 ELECTRICAL POWER SYSTEMS 3.8.4 DC Sources - Operating LCO 3.8.4 The Train A and Train B vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE.

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

Vita I Battery V may be substituted for any of the required vital batteries.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or two required vital A.1 Restore battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery charger(s) on one voltage to greater than or subsystem inoperable. equal to the minimum established float voltage.

AND A.2 Verify battery float current Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

~ 2 amps.

AND A.3 Restore vital battery 7 days charger(s) to OPERABLE status.

B. One vital DC electrical 8.1 Restore vital DC electrical 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months power subsystem power subsystem to inoperable for reasons other OPERABLE status.

than Condition A.

C. Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Associated Completion Time of Condition A or B AND not met.

C.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (continued)

Watts Bar - Unit 2 3.8-21 Amendment 33

DC Sources - Operating 3.8.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. One or two DG DC battery D.1 Restore DG battery 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months charger(s) on one train terminal voltage to inoperable. greater than or equal to the minimum established float voltage.

AND D.2 Verify battery float current Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

s; 1 amp.

AND D.3 Restore DG battery 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months charger(s) to OPERABLE status.

E. One DG DC train E.1 Restore DG DC train to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable for reasons other OPERABLE status.

than Condition D.

F. Required Action and F.1 Declare associated DG(s) Immediately Associated Completion inoperable.

Time of Condition D or E not met.

OR One or more DG DC battery charger(s) in redundant trains inoperable.

Watts Bar - Unit 2 3.8-22 Amendment 33

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify vital battery terminal voltage is greater than or 7 days equal to the minimum established float voltage.

SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 days equal to the minimum established float voltage.

SR 3.8.4.3 Verify for the vital batteries that the alternate feeder 7 days breakers to each required battery charger are open.

SR 3.8.4.4 Verify correct breaker alignment and indicated power 7 days availability for each DG 125 V DC distribution panel and associated battery charger SR 3.8.4.5 Verify each vital battery charger supplies ~ 200 amps 18 months at greater than or equal to the minimum established float voltage for ~ 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

OR Verify each vital battery charger can recharge the battery to the fully charged state within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months while supplying the largest combined demands of the various continuous steady state loads, after a battery discharge to the bounding design basis event discharge state.

SR 3.8.4.6 -------------------------------NO TE------------------------------

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG battery charger can recharge the 18 months battery to the fully charged state within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months while supplying the largest combined demands of the various continuous steady state loads, after a battery discharge to the bounding design basis event discharge state.

(continued)

Watts Bar - Unit 2 3.8-23 Amendment 33

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.7 -------------------------------NO TES----------------------------

1. The modified performance discharge test in SR 3.8.6.7 may be performed in lieu of the service test in SR 3.8.4.7.

2. This Surveillance is not performed in MODE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is adequate to supply, and 18 months maintain in OPERABLE status, the required emergency loads and any connected nonsafety loads for the design duty cycle when subjected to a battery service test.

Watts Bar - Unit 2 3.8-24 Amendment 33

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Watts Bar - Unit 2 3.8-25 Amendment 33

DC Sources - Shutdown 3.8.5 3.8 ELECTRICAL POWER SYSTEMS 3.8.5 DC Sources - Shutdown LCO 3.8.5 Vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems - Shutdown" and to support the Diesel Generators (DGs) required by LCO 3.8.2, "AC Sources - Shutdown."

NOTES------------------------------------------

Vita I Battery V may be substituted for any of the required vital batteries.

APPLICABILITY: MODES 5 and 6, During movement of irradiated fuel assemblies.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or two required A.1 Restore battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months vital battery charger(s) voltage to greater than or on one subsystem equal .to the minimum inoperable. established float voltage.

AND AND The redundant A.2 Verify battery float current Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months subsystem vital battery ::. 2 amps.

and charger(s)

OPERABLE. AND A.3 Restore battery charger(s) to 7 days OPERABLE status.

(continued)

Watts Bar - Unit 2 3.8-26 Amendment 33

DC Sources - Shutdown 3.8.5 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. One or more required B.1.1 Declare affected required Immediately vital DC electrical power feature(s) inoperable.

subsystems inoperable for reasons other than OR Condition A. .

B.2.1 Suspend CORE Immediately OR ALTERATIONS.

Required Actions and AND associated Completion Time of Condition A not B.2.2 Suspend movement of Immediately met. irradiated fuel assemblies.

AND B.2.3 Initiate action to suspend Immediately operations involving positive reactivity additions.

AND B.2.4 Initiate action to restore Immediately required DC electrical power subsystems to OPERABLE status.

C. One required DG DC C.1 Declare associated DG Immediately electrical power inoperable.

subsystem inoperable.

Watts Bar - Unit 2 3.8-27 Amendment 33

DC Sources - Shutdown 3.8.5 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.5.1 -----------------------------NOTE-----------------------------

T he following SRs are not required to be performed: SR 3.8.4.5, SR 3.8.4.6, and SR 3.8.4.7.

For DC sources required to be OPERABLE, the In accordance with following SRs are applicable: applicable SRs SR 3.8.4.1 SR 3.8.4.5 SR 3.8.4.2 SR 3.8.4.6 SR 3.8.4.3 SR 3.8.4.7 SR 3.8.4.4 Watts Bar - Unit 2 3.8-28 Amendment 33

Battery Parameters 3.8.6 3.8 ELECTRICAL POWER SYSTEMS 3.8.6 Battery Parameters LCO 3.8.6 Battery parameters for Train A and Train B electrical power subsystem 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within limits.

APPLICABILITY: When associated DC electrical power subsystems and DGs are required to be OPERABLE.

ACTIONS

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

Separate Condition entry is allowed for each battery bank.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or two required A.1 Perform SR 3.8.4.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months vital battery(ies) on one subsystem with one or AND more battery cells float voltage < 2.07 V. A.2 Perform SR 3.8.6.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months AND A.3 Restore affected cell voltage 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

2.07V.

B. One or two required 8.1 Perform SR 3.8.4.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months vital battery(ies) on one subsystem with float AND current > 2 amps.

8.2 Restore vital battery float 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months current to s 2 amps.

(continued)

Watts Bar - Unit 2 3.8-29 Amendment 33

Battery Parameters 3.8.6 (ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME C. One or two DG C.1 Perform SR 3.8.4.2. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery(ies) on one train with one or more AND battery cells float voltage< 2.07 V. C.2 Perform SR 3.8.6.2. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months AND C.3 Restore affected cell voltage 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

2.07V.

D. One or two DG D. 1 Perform SR 3.8.4.2. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months battery(ies) on one train with float current AND

> 1 amp.

D.2 Restore DG battery float 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months current to $; 1 amp.

NOTE------------------ ------------------NO TE------------------

Required Action E.2 shall be Required Actions E.1 and E.2 are completed if electrolyte level only applicable if electrolyte level was below the top of plates. was below the top of plates.

E. One or two required E.1 Restore electrolyte level to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months vital battery(ies) on one above top of plates.

subsystem with one or more cells electrolyte AND level less than minimum established design E.2 Verify no evidence of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months limits. leakage.

OR AND One or two DG E.3 Restore electrolyte level to 31 days battery(ies) on one train greater than or equal to with one or more cells minimum established design electrolyte level less limits.

than minimum established design limits.

(continued)

Watts Bar - Unit 2 3.8-30 Amendment 33

Battery Parameters 3.8.6 (ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME F. One or two required F.1 Restore battery pilot cell 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months vital battery(ies) on one temperature to greater than subsystem with pilot cell or equal to minimum electrolyte temperature established design limits.

less than minimum established design limits.

OR One or two DG battery(ies) on one train with pilot cell electrolyte temperature less than minimum established design limits.

G. One or more vital G.1 Restore battery parameters 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months batteries in redundant for vital batteries in one subsystems with battery subsystem to within limits.

parameters not within limits.

H. One or more DG H.1 Restore battery parameters 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months batteries in redundant for DG batteries in one train trains with battery to within limits.

parameters not within limits.

(continued)

Watts Bar - Unit 2 3.8-30a Amendment 33

Battery Parameters 3.8.6 (ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME I. Required Action and 1.1 Declare associated battery Immediately associated Completion inoperable.

Time of Condition A, B, C, D, E, F, G, or H not met.

OR One or two required vital battery(ies) on one subsystem with one or more battery cells float voltage < 2.07 V and float current > 2 amps.

OR One or two DG battery(ies) on one train with one or more battery cells float voltage < 2.07 V and float current > 1 amp.

Watts Bar - Unit 2 3.8-30b Amendment 33

Battery Parameters 3.8.6 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 -----------------------------NOTE--------------------------------

Not required to be met when vital battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.1.

Verify each vital battery float current is ::; 2 amps. 7 days SR 3.8.6.2 -----------------------------NO TE-------------------------------

Not required to be met when DG battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.2.

Verify each DG battery float current is ::; 1 amp. 7 days SR 3.8.6.3 Verify each required vital battery and each DG 31 days battery pilot cell float voltage is ~ 2.07 V.

SR 3.8.6.4 Verify each required vital battery and each DG 31 days battery connected cell electrolyte level is greater than or equal to minimum established design limits.

SR 3.8.6.5 Verify each required vital battery and each DG 31 days battery pilot cell temperature is greater than or equal to minimum established design limits.

SR 3.8.6.6 Verify each required vital battery and each DG 92 days battery connected cell float voltage is ~ 2.07 V.

(continued)

Watts Bar - Unit 2 3.8-31 Amendment 33

Battery Parameters 3.8.6 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.6.7 ------------------------------N()TES------------------------------

This Surveillance is not performed in M()DE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is?:: 80% of the 60 months manufacturer's rating when subjected to a performance discharge test or a modified performance discharge test.

12 months when battery shows degradation or has reached 85% of expected life with capacity < 100% of manufacturer's rating 24 months when battery has reached 85% of the expected life with capacity 2 100% of manufacturer's rating Watts Bar - Unit 2 3.8-32 Amendment 33

Procedures, Programs, and Manuals 5.7

5. 7 Procedures, Programs, and Manuals 5.7.2.22 Battery Monitoring and Maintenance Program This Program provides controls for battery restoration and maintenance. The program shall be in accordance with IEEE Standard (Std) 450-2002, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," as endorsed by Regulatory Guide 1.129, Revision 2 (RG), with RG exceptions and program provisions as identified below:

a. The program allows the following RG 1.129, Revision 2 exceptions:

1. Battery temperature correction may be performed before or after conducting discharge tests.

2. RG 1.129, Regulatory Position 1, Subsection 2, "References," is not applicable to this program.

3. In lieu of RG 1.129, Regulatory Position 2, Subsection 5.2, "Inspections," the following shall be used: "Where reference is made to the pilot cell, pilot cell selection shall be based on the lowest voltage cell in the battery."

4. In Regulatory Guide 1.129, Regulatory Position 3, Subsection 5.4.1, "State of Charge Indicator," the following statements in paragraph (d) may be omitted: "When it has been recorded that the charging current has stabilized at the charging voltage for three consecutive hourly measurements, the battery is near full charge. These measurements shall be made after the initially high charging current decreases sharply and the battery voltage rises to approach the charger output voltage."

5. In lieu of RG 1.129, Regulatory Position 7, Subsection 7.6, "Restoration", the following may be used: "Following the test, record the float voltage of each cell of the string."

b. The program shall include the following provisions:

1. Actions to restore battery cells with float voltage < 2.13 V;

2. Actions to determine whether the float voltage of the remaining battery cells is .:: 2.13 V when the float voltage of a battery cell has been found to be < 2.13 V; Watts Bar-Unit 2 5.0-27a Amendment 33

Procedures, Programs, and Manuals 5.7

5. 7 Procedures, Programs, and Manuals 5.7.2.22 Battery Monitoring and Maintenance Program (continued)

3. Actions to equalize and test battery cells that had been discovered with electrolyte level below the top of the plates;

4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and

5. A requirement to obtain specific gravity readings of all cells at each discharge test, consistent with manufacturer recommendations.

Watts Bar-Unit 2 5.0-27b Amendment 33

UNITED STATES WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 130 TO FACILITY OPERATING LICENSE NO. NPF-90 AND AMENDMENT NO. 33 TO FACILITY OPERATING LICENSE NO. NPF-96 TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-390 AND 50-391

1.0 INTRODUCTION

By letter dated November 29, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18334A389), as supplemented by letters dated June 7, 2019; September 4, 2019; and October 10, 2019 (ADAMS Accession Nos. ML19158A394, ML19247C981, and ML19283G172, respectively), Tennessee Valley Authority (TVA, the licensee), requested amendments to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (Watts Bar), Units 1 and 2, respectively. On June 18, 2019, the U.S. Nuclear Regulatory Commission (NRC, the Commission) staff published a proposed no significant hazards consideration determination in the Federal Register (84 FR 28348) for the proposed amendments.

Subsequently, by letter dated September 4, 2019, the licensee provided additional information that expanded the scope of the amendment request as originally noticed in the Federal Register. Accordingly, the NRC staff published a second proposed no significant hazards consideration determination in the Federal Register on September 12, 2019 (84 FR 48180),

which superseded the original notice in its entirety. The supplement dated October 10, 2019, provided additional information that clarified the application, did not expand the scope of the application as noticed, and did not change the NRC staff's proposed no significant hazards consideration determination, as published in the Federal Register on September 12, 2019.

The proposed license amendments would revise the Watts Bar, Units 1 and 2, Technical Specifications (TSs) to adopt the NRG-approved Technical Specifications Task Force Traveler, TSTF-500, Revision 2, "DC [Direct Current] Electrical Rewrite - Update to TSTF-360," dated September 22, 2009 (ADAMS Accession No. ML092670242). Specifically, the licensee proposed changes to the TS requirements related to DC electrical power systems in TS 3.8.4, "DC Sources - Operating"; TS 3.8.5, "DC Sources - Shutdown"; and TS 3.8.6, "Battery Cell Parameters." Additionally, the licensee proposed to add a new program titled "Battery Monitoring and Maintenance Program" to TS Section 5.7, "Procedures, Programs, and Manuals," and relocate a number of surveillance requirements (SRs) in TS 3.8.4 and Table 3.8.6-1 to the new program.

Enclosure 3

The licensee also proposed a plant-specific TS 3.8.4 condition for one or more inoperable diesel generator (DG) DC battery charger(s) in redundant trains that is beyond the scope of TSTF-500, Revision 2.

The proposed changes to TS 3.8.4 in the September 4, 2019, letter, superseded the changes to TS 3.8.4 in the June 7, 2019, and November 29, 2018, letters. The proposed changes to TS 3.8.6 in the June 7, 2019, letter superseded the changes to TS 3.8.6 in the November 29, 2018, letter. The proposed TSTF-500-related changes to TSs 3.8.4, 3.8.5, and 3.8.6 include the following:

New condition, required action, and completion time (CT) for inoperable vital battery charger and DG DC and alternate testing criteria for the battery chargers for TS Limiting Conditions for Operation (LCOs) 3.8.4 and 3.8.5.

Relocation of a number of SRs in TS 3.8.4 that perform preventative maintenance on the safety-related batteries to a licensee-controlled program.

Modification of TS 3.8.6 by relocating Table 3.8.6-1, "Battery Cell Parameter Requirements," to a licensee-controlled program, by addition of specific conditions and required actions with associated CTs for out-of-limits conditions for battery cell voltage, electrolyte level, and electrolyte temperature.

Specific SRs are revised and added for verification of battery parameters.

Addition of a new program titled "Battery Monitoring and Maintenance Program" to TS 5. 7 for the maintenance and monitoring of vital and DG batteries and for the relocation of other mentioned TS items.

The Notice of Availability (NOA) for TSTF-500, Revision 2, was published in the Federal Register on September 1, 2011 (76 FR 54510), to announce the availability of the model application and model safety evaluation (SE) (ADAMS Accession No. ML111751792) for plant-specific adoption of TSTF-500, Revision 2, as part of the consolidated line item improvement process. This NOA was later corrected to clarify that TSTF-500 was available for plant-specific adoption, but not under the consolidated line item improvement process. The clarifying NOA was published in the Federal Register on November 8, 2011 (76 FR 69296).

TSTF-500, Revision 2, Attachment B, "Revisions to Revision 1 of the ISTS [Improved Standard Technical Specifications] NUREGs," provides the changes to Revision 1 of the ISTS NUREGs to incorporate TSTF-500. TSTF-500, Revision 2, states that the changes in Attachment B should be used for plants that have not adopted TSTF-360. Since Watts Bar is a Westinghouse plant that has not adopted TSTF-360, the NRC staff used the changes to NUGEG-1431, Revision 1, "Standard Technical Specifications Westinghouse Plants," in Attachment B of TSTF-500, Revision 2, as the model for evaluating the proposed Wats Bar TS changes.

2.0 REGULATORY EVALUATION

The NRC staff used following regulatory requirements to review the LAR:

Title 10 of the Code of Federal Regulations Part 50 ( 10 CFR Part 50)

The regulation at Appendix A to 10 CFR Part 50, "General Design Criteria for Nuclear Power Plants" (GDC) 17, "Electric power systems," states, in part, that:

An onsite electric power system and an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. [ ... ]

The onsite electric power supplies, including the batteries, and the onsite electric distribution system, shall have sufficient independence, redundancy, and testability to perform their safety functions assuming a single failure.

Electric power from the transmission network to the onsite electric distribution system shall be supplied by two physically independent circuits (not necessarily on separate rights of way) designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions.[ ... ]

Provisions shall be included to minimize the probability of losing electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power unit, the loss of power from the transmission network, or the loss of power from the onsite electric power supplies.

The regulation at 10 CFR Part 50, Appendix A, GDC 1, "Quality standards and records,"

states, in part, that, "Structures, systems, and components important to safety shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions to be performed."

The regulation at 10 CFR Part 50, Appendix A, GDC 18, "Inspection and testing of electric power systems," states, in part, that, "Electric power systems important to safety shall be designed to permit appropriate periodic inspection and testing of important areas and features .... "

The regulation at 10 CFR 50.36, "Technical Specifications," establishes the requirements related to the content of TSs. Pursuant to 10 CFR 50.36(c), TSs are required to include items in five specific categories related to station operation:

(1) safety limits, limiting safety system settings, and limiting control settings; (2) LCOs; (3) SRs; (4) design features; and (5) administrative controls. The proposed changes to the Watts Bar TSs relate to the LCO, SR, and administrative control categories.

The regulation at 10 CFR 50.65, "Requirements for monitoring the effectiveness of maintenance at nuclear power plants," Section (a)(3), states, in part, that, "Performance

and condition monitoring activities and associated goals and preventive maintenance activities shall be evaluated at least every refueling cycle provided the interval between evaluations does not exceed 24 months .... "

The NRC staff used the following regulatory guidance documents for review of the LAR:

Regulatory Guide (RG) 1.129, Revision 2, "Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants," dated February 2007 (ADAMS Accession No. ML063490110), provides guidance with respect to the maintenance, testing, and replacement of vented lead-acid storage batteries in nuclear power plants. This RG endorses, in part, the Institute of Electrical and Electronics Engineers (IEEE) Standard (Std.) 450-2002, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications."

RG 1.32, Revision 2, "Criteria for Safety-Related Electric Power Systems for Nuclear Power Plants," dated February 1977 (ADAMS Accession No. ML003739990), provides guidance with respect to physical separation, electrical isolation, and redundancy for DC systems for to prevent the occurrence of common mode failures. This RG endorses, in part, IEEE Std. 308-1974, "IEEE Standard Criteria for Class 1E Power Systems for Nuclear Power Generating Stations."

RG 1. 75, Revision 0, "Physical Independence of Electric Systems," dated February 1974, provides guidance with respect to the physical independence requirements of the circuits and electric equipment that comprise or are associated with safety systems.

TSTF-500, Revision 2, "DC Electrical Rewrite - Update to TSTF-360."

The model application and SE for plant-specific adoption of TSTF-500, Revision 2 (ADAMS Accession No. ML111751792), as published for availability in the Federal Register on September 1, 2011 (76 FR 54510).

3.0 TECHNICAL EVALUATION

3.1 Design Features of the Watts Bar, Units 1 and 2, Vital DC Power System As described in Section 8.3, "Onsite (Standby) Power System," of the Watts Bar Updated Safety Analysis Report (UFSAR) and in Enclosure 6 of the November 29, 2018, letter, the 125 volt (V)

DC vital control power system is a Class 1E DC electrical power system that provides control power for engineered safety features equipment, emergency lighting, vital inverters, and other safety-related DC powered equipment for the entire plant. The system capacity is sufficient to supply these loads during normal operation and to permit safe shutdown and isolation of the reactor for the station blackout (SBO) condition.

The 125 volt (V) DC vital control power system is composed of four channels ( Channels I, II, 111, and IV) in two trains A and B that are shared by both Units 1 and 2. These four channels provide emergency power to the 120 V alternating current (AC) vital power system that furnishes control power to the reactor protection system. Each channel consists of a battery charger that supplies normal DC power, a battery for emergency DC power, and a battery board

that facilitates load grouping and provides circuit protection. Each train is a 125 V DC vital electrical power subsystem, as described in Enclosure 2 of the September 4, 2019, letter.

Vital Battery Boards I, II, Ill, and IV have manual access to two pairs of spare (backup) chargers for use upon loss of the normal chargers. Each pair of spare chargers is mechanically interlocked such that only one charger in each pair can be used at a time. In addition, Vital Battery Boards I, II, Ill, and IV have manual access to a fifth 125 V DC vital battery system (vital battery V and charger V). Vital battery V serves as a replacement for any one of the four 125 V DC vital batteries during testing, maintenance, and outages with no loss of system reliability under any mode of operation.

During normal operation, the DC loads are powered from the battery chargers in the float charge mode. Float charge is the condition in which the charger is supplying the connected loads, and the battery cells are receiving adequate current to optimally charge the battery. The purpose of the float charge is to overcome the internal losses of the battery such that the battery is maintained in a fully charged state. In case of loss of normal power to the battery charger, the DC loads are automatically powered from the station batteries.

Each battery charger has an ample power output capacity for the steady state operation of connected loads required during normal operation, while maintaining its battery bank fully charged. Each battery charger also has enough excess capacity to restore the battery from the design minimum charged to its fully charged state while supplying normal steady state loads.

With the batteries in the fully charged condition, the DC electrical power system has the capacity to supply the required loads for a minimum of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months with an SBO event. Each battery is designed with excess capacity above that required by the design duty cycles to allow for temperature variations and other factors.

Each battery is separately housed in a ventilated room apart from its charger and distribution centers. Each DC electrical power subsystem is in an area separated physically and electrically from the other subsystem to ensure that a single failure in one subsystem does not cause a failure in a redundant subsystem. There is no sharing of dedicated components such as batteries, battery chargers, or distribution panels between redundant Class 1E subsystems.

Design Features of the Units 1 and 2 DG DC Power System In Enclosure 1, Section 2.0, "Assessment," of its November 29, 2018, letter, the licensee stated:

A DG battery subsystem is provided for each DG. Each subsystem is comprised of a battery, dual battery charger assembly, distribution center, and cabling. The DG battery provides DC control power and field-flash when the charger is unavailable. If 480V AC is available, the charger supplies the normal DC loads, maintains the battery in a fully charged condition, and recharges the battery while supplying the required loads regardless of the status of the plant. The batteries are physically and electrically independent. The DG control power systems are ungrounded and have ground detection instrumentation. Each DG battery has sufficient capacity when fully charged to supply the required loads for a minimum of four-hours following a loss of normal power. (... ] Each battery is normally required to supply loads only during the time interval between loss of normal feed to its charger and the receipt of emergency power to the charger from its respective diesel-generator. The batteries, comprised of 58 cells, have adequate

capacity considering the minimum terminal voltage of 105 volts and derating for 50°F temperature and aging.

The normal supply of DC current to the battery boards is from the battery charger. [ ... ] Each of the chargers (normal and alternate) in the dual charger assembly has a dedicated AC source from two respective 480V AC Diesel Generator Auxiliary Boards.

3.2 Evaluation of Proposed Changes The Watts Bar, Units 1 and 2, DC electrical power systems include vital DC and DG DC electrical power subsystems. In Enclosure 1 of its November 29, 2018, letter, the licensee stated that the vital batteries and DG batteries have different required float currents for determining that their respective batteries are charged. Therefore, the proposed Units 1 and 2 TSs include separate conditions for inoperable batteries and battery chargers for the vital DC and DG DC electrical power subsystems, and separate SRs for verifying the float currents for the required vital batteries and DG batteries. In addition, the licensee applied the term "required" to (1) the vital battery charger to differentiate between the inservice battery charger(s) and the spare battery charger and to (2) the vital battery to differentiate between the vital batteries I-IV and the vital battery V in the vital 125 V DC subsystem.

The Units 1 and 2 DG DC subsystems are plant-specific. The NRC staff used the ISTS for the station DC electrical power subsystem provided in NUGEG-1431, Revision 1, in Attachment B of TSTF-500, Revision 2, to review the proposed changes to the TSs for the DG DC electrical power subsystems.

3.2.1 TS 3.8.4, "DC Sources - Operating," Changes The current TS 3.8.4 LCOs, actions, and SRs for Watts Bar, Units 1 and 2, are similar, except for the LCO notes. Only the Unit 1 TS 3.8.4 LCO includes a note that allows the substitution of the common spare (C-S) DG and its associated DC electrical power subsystem for any of the required DGs and their associated DC electrical power subsystems.

The licensee proposed to revise Units 1 and 2 TS 3.8.4 LCOs, conditions, required actions, and SRs. The proposed changes would (1) revise the LCOs, (2) add new conditions to address the operability of both units' vital DC and DG battery chargers, (3) modify current SRs that require verification of batteries and chargers design capabilities and the battery's terminal voltage, and (4) relocate current preventive maintenance SRs and a current SR that require verification of a battery capacity.

The proposed changes to TS 3.8.4 LCOs, actions, and SRs for Units 1 and 2, are similar, except for the deletion of the Unit 1 TS 3.8.4 LCO note related to the C-S DG. The NRC staff's following evaluation of the proposed changes to TS 3.8.4 is applicable to both Units 1 and 2.

3.2.1.1 Watts Bar, Units 1 and 2, TS 3.8.4; Current LCO 3.8.4 (Revised), Change ( 1)

Unit 1 TS 3.8.4 Current LCO 3.8.4 (Revised)

Current Unit 1, TS 3.8.4, LCO 3.8.4, states:

LCO 3.8.4 Four channels of vital DC and four Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE.

t'IJ()l"ES------------------------------------

1. Vital Battery V may be substituted for any of the required vital batteries

2. The C-S DG and its associated DC electrical power subsystem may be substituted for any of the required DGs and their associated DC electrical power subsystem Revised Unit 1, TS 3.8.4, LC() 3.8.4, would state:

LC() 3.8.4 The Train A and l"rain B vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE

1'\JOl"E-------------------------------------

Vital Battery V may be substituted for any of the required vital batteries l"he Unit 1 LCO 3.8.4 is applicable in Modes 1 through 4.

Unit 2, l"S 3.8.4, Current LC() 3.8.4 (Revised)

Current Unit 2, TS 3.8.4, LCO 3.8.4, states:

LCO 3.8.4 Four channels of vital DC and four Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE.

1'\JOTE-------------------------------------------

Vital Battery V may be substituted for any of the required vital batteries.

Revised Unit 2, TS 3.8.4, LC() 3.8.4, would state:

LCO 3.8.4 The l"rain A and l"rain B vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE

1'\J()TE-------------------------------------------

Vital Battery V may be substituted for any of the required vital batteries.

Unit 2 LCO 3.8.4 is applicable in Modes 1 through 4.

Evaluation of Units 1 and 2 TS 3.8.4: Current LCO 3.8.4 (Revised), Change (1)

The licensee proposed to revise the TS LCO 3.8.4 statement for the vital DC sources from "four channels of vital DC electrical power subsystems" to Train A and Train B vital DC electrical power subsystems" for both Units 1 and 2. In Enclosure 6 of its November 29, 2018, letter, the licensee stated that the four vital DC channels (Channels I, II, Ill, and IV) are grouped in two trains (Channels I and Ill in Train A and Channels II and IV in Train B) shared between both Units 1 and 2.

The NRC staff finds that since the four vital DC channels are grouped in two trains A and B, the proposed LCO 3.8.4 with respect to the vital DC electrical power subsystems is consistent with the current TS LCO 3.8.4 requirement for vital DC electrical power subsystem, and is, therefore, acceptable.

The licensee also proposed to revise the TS LCO 3.8.4 statement for the DG DC electrical power sources from "four DG DC electrical power subsystems" to "Train A and Train B DG DC electrical power subsystems" for both Units 1 and 2. In its September 4, 2019, letter, the licensee explained the relationship between the DG DC electrical power subsystems and trains A and B, as follows:

Each DG DC electrical power subsystem is independent and dedicated to its respective DG. The DGs that are supported by the DG DC electrical power subsystems are arranged in redundant trains (i.e., DG 1A-A and DG 2A-A are in Train A, and DG 1B-B and DG 2B-B are in Train B). Therefore, there are two DG DC electrical power subsystems associated with each DG DC electrical power train. When one or two DGs in a train are inoperable, that train is incapable of performing the safety function and must rely on the redundant train to mitigate an event. Likewise, if one or two of the DG DC electrical power subsystems in a train are inoperable, that train is incapable of performing the safety function and must rely on the redundant train to mitigate an event. Therefore, the LCO requires Train A and Train B DG DC electrical power subsystems to be OPERABLE to support the redundancy of the standby electrical power system.

In Enclosure 4, "New Regulatory Commitment," of its September 4, 2019, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to reflect consistent terminology regarding the arrangement of the four DG DC electrical power subsystems with one subsystem supporting each DG.

The NRC staff finds that since the four DG DC electrical power subsystems are grouped in two electrical power trains A and B with two DG DC electrical power subsystems per train, the proposed change to the LCO 3.8.4 with respect to the DG DC electrical power subsystems is consistent with the existing TS LCO 3.8.4 requirement for the DG DC electrical power subsystem, and is, therefore, acceptable.

The licensee proposed deleting Unit 1 TS LCO 3.8.4 Note 2, which allows the C-S DG to be substituted for any of the required DGs. In Enclosure 1 of its November 29, 2018, letter, the licensee stated that the C-S DG is not being maintained and, therefore, it cannot meet the requirements specified in TS 3.8.1 that would allow it to be substituted for any required DG.

The NRC staff finds the proposed deletion of the Unit 1 TS LCO 3.8.4 note acceptable because the change does not impact TS 3.8.4 requirements for the DG DC electrical power subsystems.

Based on the above, the NRC staff concludes that the proposed revised Units 1 and 2 LCOs 3.8.4 are acceptable because the licensee has identified the minimum components needed for safe operation of the facility in Modes 1 through 4, as required by 10 CFR 50.36(c)(2).

3.2.1.2 Watts Bar, Units 1 and 2, TS 3.8.4, New Condition A (Added), Change (2)

New Units 1 and 2, TS 3.8.4, Condition A, would state:

A. One or two required vital battery charger(s) on one subsystem inoperable.

New Units 1 and 2, TS 3.8.4, Required Actions A.1, A.2, and A.3, would state:

A.1 Restore battery terminal voltage to greater than or equal to the minimum established float voltage.

A.2 Verify battery float current :s; 2 amps.

A.3 Restore vital battery charger(s) to OPERABLE status.

New CTs for Units 1 and 2, TS 3.8.4, New Required Actions A.1, A.2, and A.3, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ," "Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ," and "7 days," respectively.

Evaluation of Watts Bar, Units 1 and 2, TS 3.8.4: New Condition A Change (2)

New Condition A would apply when one or two vital battery charger(s) on one subsystem are inoperable. The new Condition A would have three associated new Required Actions A.1, A.2, and A.3. The new required actions provide a tiered response that focuses on returning the battery to the fully charged state and restoring a fully qualified charger to operable status in a specific time period.

New Required Action A.1 would require the affected battery terminal voltage to be restored to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The battery charger, in addition to maintaining the battery operable, provides control power for safety-related DC powered equipment and supports safe shutdown and isolation of the reactor for an SBO event. The 2-hour CT provides an allowance for returning an inoperable charger to operable status or for reestablishing an alternate means (e.g., spare battery charger) of restoring battery terminal voltage to greater than or equal to the minimum established float voltage. According to Section 8.3.2, "DC Power System," of the Watts Bar UFSAR, the 125 V /

DC vital control power system includes two pairs of spare battery chargers for the four DC channels (one pair for two channels), with each pair of spare chargers mechanically interlocked such that only one charger in each pair can be used at a time. The spare chargers can be manually connected to the battery boards upon loss of the normal chargers. Watts Bar UFSAR, Figure 8.1-3, "120V AC & 125V DC Vital Plant Control Power System," shows that one pair of battery chargers is shared between DC Channels I and II, and the other pair of battery chargers

is shared between DC Channels Ill and IV. Thus, if two vital battery chargers in one vital DC electrical power subsystem (e.g., chargers in DC Channels I and Ill in Train A) are inoperable in new Condition A, two spare chargers with one spare charger in each pair (i.e., one spare charger for the DC Channel I and one spare charger for DC Channel Ill) will be used to substitute for the two inoperable battery chargers. According to Section 8.3.2 and Figure 8.1-3, all the normal and spare chargers have the same rated capacity of 200 amps. Thus, the spare vital battery charger(s) will be able to restore the affected battery(ies) terminal voltage(s) to greater than or equal to the minimum established float voltage within the 2-hour CT. At the end of the 2-hour CT, a terminal voltage of at least the minimum established float voltage provides indication that the battery is on the exponential charging current portion of its recharging cycle.

This provides assurance that the battery can be restored to its fully charged condition from any discharge that occurs due to the charger inoperability. The proposed new Required Action A.1 will allow the DC bus to remain energized and the battery discharge to be terminated and is, therefore, acceptable.

New Required Action A.2 would require that the battery float current be verified as less than or equal to 2 amps once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This would indicate that if the battery had been discharged as the result of the inoperable battery charger, it had been recharged and fully capable of supplying the maximum expected load requirement. In its letter dated June 7, 2019, the licensee stated that the vital batteries would be fully recharged in less than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to less than 2 amps, considering the capacity of the battery chargers (rated for 200 amps) and the relatively small amount of capacity (200 amp-hours) that would be removed from the batteries (rated for 2320 amp-hours) within the 2-hour allowed time to place a battery charger on the battery. If at the expiration of the 12-hour period the battery float current is greater than 2 amps, then the battery is considered inoperable (see Section 3.2.3.3 of this SE for a more detailed discussion on the 2-amp float current value). The verification of float current provides assurance that the battery has sufficient capacity to perform its safety function; therefore, the NRC staff finds the proposed new Required Action A.2 and its associated CT acceptable.

New Required Action A.3 would limit the restoration time for the inoperable battery charger to 7 days. An alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage (e.g., spare battery charger) will be in use during this time. A 7-day CT for an inoperable battery charger is acceptable if an alternate means to charge the batteries is available and is capable of being supplied power from a power source that is independent of the offsite power supply, as described in the UFSAR. In Enclosure 1, Section 2.3, "Optional Changes and Variations," of its November 29, 2018, letter, the licensee stated that the proposed 7-day CT for inoperable vital battery charger(s) is based on the availability of spare charger(s) that are used to substitute for the inoperable charger(s) and can be supplied by the associated DG(s), which is (are) independent of the offsite power supply. Watts Bar UFSAR Section 8.3.2, states that the battery spare chargers, if in service, are automatically loaded on the DGs on a loss-of-offsite power (LOOP). In addition, in Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to include in the Watts Bar UFSAR the minimum requirements for the alternate means (i.e., spare battery charger) that are used to obtain extended battery charger CT (i.e., 7-day CT), where future changes would be subject to the requirements of 10 CFR 50.59. This provides additional assurance that the alternate means (i.e., spare chargers) used to obtain the 7-day CT will be appropriately maintained by the licensee. The NRC staff finds the proposed new Required Action A.3 within the 7-day CT acceptable because the spare battery chargers provide an alternate means to charge the batteries and can be supplied power from the DGs that are independent of the offsite power supply.

Based on the above, the NRC staff concludes that the proposed TS 3.8.4 new Condition A, with its associated required actions and CTs, provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.1.3 Watts Bar, Units 1 and 2, TS 3.8.4; Current Condition A (Revised and Renumbered as Condition B), Change (3)

Current Units 1 and 2, TS 3.8.4, Condition A, states:

A. One vital DC electrical power subsystem inoperable.

Revised and renumbered Units 1 and 2, TS 3.8.4, Condition B, would state:

B. One vital DC electrical power subsystem inoperable for reasons other than Condition A.

Current Units 1 and 2, TS 3.8.4, Required Action A.1, states:

A.1 Restore vital DC electrical power subsystem to OPERABLE status.

Revised and renumbered Units 1 and 2, TS 3.8.4, Required Action B.1, would state:

B.1 Restore vital DC electrical power subsystem to OPERABLE status.

The CT for the revised and renumbered Units 1 and 2, TS 3.8.4, Required Action B.1, would remain unchanged and would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ."

Evaluation of Units 1 and 2 TS 3.8.4; Current Condition A (Revised and Renumbered as Condition B), Change (3)

Current Condition A, which applies when one vital DC electrical power subsystem is inoperable (e.g., inoperable battery and/or inoperable battery charger(s)), would be revised and renumbered as Condition B. The renumbered Condition B would apply when one vital DC electrical power subsystem is inoperable for reasons other than the new Condition A. Because the new Condition A (from Section 3.2.1.2 of this SE) will address the restoration of inoperable vital battery charger(s) within a 7-day CT, the new Condition A must be excluded from the revised and renumbered Condition B, which would have a different CT. The NRC staff finds the proposed revised and renumbered Condition B acceptable because it reflects the addition of the new Condition A to TS 3.8.4.

Current Required Action A.1 would be renumbered as Required Action B.1 with no other changes. The NRC staff finds that renumbering Required Action A.1 as B.1 is editorial in nature, and is, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed TS 3.8.4 revised and renumbered Condition B with its associated required action and CT provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.1.4 Watts Bar, Units 1 and 2, TS 3.8.4, Current Condition B (Revised and Renumbered as Condition C), Change (4)

Current Units 1 and 2, TS 3.8.4, Condition B, states:

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

Revised and renumbered Units 1 and 2, TS 3.8.4, Condition C, would state:

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

Current Units 1 and 2 TS, 3.8.4, Required Actions B.1 and B.2, state:

B.1 Be in MODE 3.

B.2 Be in MODE 5.

Renumbered Units 1 and 2, TS 3.8.4, Required Actions C.1 and C.2, would state:

C.1 Be in MODE 3.

C.2 Be in MODE 5.

The CTs for the renumbered Units 1 and 2, TS 3.8.4, Required Actions C.1 and C.2, would remain unchanged and would state "6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months " and "36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months ," respectively.

Evaluation of Units 1 and 2, TS 3.8.4: Current Condition B (Revised and Renumbered as Condition C), Change (4)

Current Condition B would be revised by adding the new Condition A (inoperable required vital battery charger) and be renumbered as Condition C. The current Required Actions B.1 and B.2 would be renumbered as Required Actions C.1 and C.2, respectively, with the same CTs. The NRC staff finds that the renumbering of Condition B and Required Actions B.1 and B.2 as Condition C and Required Actions C.1 and C.2, respectively, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered Condition C would apply when the required action and associated CT of the new Condition A (from Section 3.2.1.2 of this SE) or the revised and renumbered Condition B (from Section 3.2.1.3 of this SE) are not met. This means that the inoperable required vital battery charger or inoperable vital DC electrical power subsystem (battery) cannot be restored to operable status within the required CT of the new Condition A or the revised and renumbered Condition B. In this case, the revised and renumbered Condition C would require the unit to be brought to Mode 3 in 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months (renumbered Required Action C.1) and to Mode 5 in 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (Required Action C.2). The NRC staff finds that the revised and renumbered Condition C reflects the addition of the proposed new Condition A to TS 3.8.4 and is acceptable because, if the inoperable vital battery charger or inoperable vital DC electrical power

subsystem cannot be restored to operable status within its required CT, then the plant must be brought to a Mode in which the LCO does not apply.

Based on the above, the NRC staff concludes that the proposed TS 3.8.4 revised and renumbered Condition C with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.1.5 Watts Bar, Units 1 and 2, TS 3.8.4; New Condition D (Added), Change (5)

New Units 1 and 2, TS 3.8.4, Condition D, would state:

D. One or two DG battery charger(s) on one train inoperable.

New Units 1 and 2, TS 3.8.4, Required Actions D.1, D.2, and D.3, would state:

D.1 Restore DG DC battery terminal voltage to greater than or equal to the minimum established float voltage.

D.2 Verify battery float current :S 1 amp.

D.3 Restore DG battery charger(s) to OPERABLE status.

New CTs for Units 1 and 2, TS 3.8.4, New Required Actions D.1, D.2, and D.3, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ," "Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ," and "72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months ," respectively.

Evaluation of Units 1 and 2, TS 3.8.4; New Condition D, Change (5)

New Condition D would apply when one or two DG battery charger(s) on one train is(are) inoperable. In its September 4, 2019, letter, the licensee stated that two DG DC electrical power subsystems are associated with each DG DC electrical power train.

The new Condition D would have three associated new Required Actions D.1, D.2, and D.3. The new required actions provide a tiered response that focuses on returning the battery to the fully charged state and restoring a fully qualified charger to operable status in a specific time period.

New Required Action D.1 would require the affected DG battery terminal voltage to be restored to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The DG battery charger, in addition to maintaining the DG battery operable, supports the recovery of AC power following events such as LOOP. The 2-hour CT provides an allowance for returning an inoperable charger to operable status or for reestablishing an alternate means (e.g., spare battery charger) of restoring battery terminal voltage to greater than or equal to the minimum established float voltage.

In Enclosure 1, Section 2.0, of its November 29, 2018, letter, the licensee stated that each DG battery subsystem includes a normal battery charger and an alternate battery charger in a dual battery charger assembly, and the alternate charger is selected by the 125 V DC transfer switch included in the assembly if the normal charger is unavailable.

The NRC staff notes that if an operable alternate battery charger is automatically selected when the normal battery charger is inoperable, the proposed new Condition D will not be entered until the alternate battery charger also becomes inoperable. In this case, an alternate means would not be available to restore the affected DG battery terminal voltage to greater than or equal to the minimum established float voltage (new Required Action D.1 ). Thus, the NRC staff requested the licensee to discuss the TS requirements for an operable DG battery subsystem and an operable DG DC train, and the alternate means that will be used to restore a DG battery terminal voltage to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in the proposed new Condition D.

In its September 4, 2019, letter, the licensee stated that ( 1) each DG DC electrical power subsystem requires one operable battery charger in a dual battery charger assembly for operability, and (2) each DG DC electrical power train, which includes two DG DC electrical power subsystems, requires two operable DG DC battery chargers, each connected to its respective DG battery, for operability. The licensee also stated:

When one or both required DG DC battery charger(s) in a DG DC electrical power train are inoperable, TS LCO 3.8.4, Condition D is entered. Upon declaring the DG DC battery charger(s) inoperable, the Completion Times for Required Actions D.1, D.2, and D.3 run concurrently. Upon discovery of an inoperable DG DC battery charger, the alternate DG battery charger is manually selected at the respective dual battery charger, thereby providing a qualified means to charge the respective DG battery.

DG DC battery terminal voltage would be restored to greater than or equal to the minimum established float voltage after the alternate DG DC battery charger(s) are manually selected at the respective DG DC dual battery charger.

The NRC staff finds that, because the alternate DG battery charger in each dual battery charger assembly is manually selected when the normal DG battery charger is inoperable, the alternate DG battery charger will provide an acceptable alternate means of restoring the DG battery terminal voltage to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in the new Condition D. At the end of the 2-hour CT, a terminal voltage of at least the minimum established float voltage provides indication that the battery is on the exponential charging current portion of its recharging cycle. This provides assurance that the DG battery can be restored to its fully charged condition from any discharge that might have occurred due to the charger inoperability. The proposed new Required Action D.1 will allow the DC bus to remain energized and the battery discharge to be terminated; therefore, the NRC staff finds the proposed new Required Action D.1 with associated CT to be acceptable.

New Required Action D.2 would require that the battery float current be verified as less than or equal to 1 amp once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This would indicate that if the battery had been discharged as the result of the inoperable battery charger, it had been recharged and fully capable of supplying the maximum expected load requirement. In its letter dated June 7, 2019, the licensee stated that the DG batteries would be fully recharged in less than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to less than 1 amp, considering the capacity of the battery chargers (rated for 20 amps) and the relatively small amount of capacity (20.82 amp-hours) that would be removed from the batteries (rated for 192 amp-hours) within the 2-hour allowed time to place an alternate battery charger on the battery. If, at the expiration of the 12-hour period, the DG battery float current is greater than 1 amp, then the battery is considered inoperable (see Section 3.2.3.3 of this SE for a more detailed discussion on the 1-amp float current value). The verification of float current provides

assurance that the battery has sufficient capacity to perform its safety function; therefore, the NRG staff finds the proposed new Required Action D.2 and its associated CT acceptable.

New Required Action D.3 would limit the restoration time for the inoperable battery charger to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . This action is applicable if an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage has been used (e.g., spare battery charger). In its September 4, 2019, letter, the licensee stated that the alternate DG battery charger in the dual battery charger assembly will be manually selected to restore the affected DG terminal voltage to greater than or equal to the minimum established float voltage.

The licensee also stated:

Selecting the alternate DG DC battery charger provides a qualified means to charge the respective DG battery, thereby allowing Condition D to be exited.

The 72-hour Completion Time reflects a reasonable time to effect restoration of a qualified battery charger to OPERABLE status. If the alternate battery charger is also inoperable, but is otherwise capable of restoring terminal voltage to the minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , operation could continue until the 72-hour Completion Time {CT) expires, or until a DG DC battery charger is restored to an operable status.

In its letter dated June 7, 2019, the licensee stated that the 72-hour CT will allow enough time to correct a battery charger problem and is commensurate with the importance of maintaining the DG DC subsystems' capability to respond to a design-basis event. The NRG staff notes that if the inoperable alternate DG battery charger still has the capacity and capability to fully recharge the DG battery (new Required Action D.2), it will provide an acceptable alternate means of recharging the DG battery to allow the 72-hour CT.

Based on the above, the NRG staff concludes that the proposed TS 3.8.4 new Condition D with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.1.6 Watts Bar, Units 1 and 2, TS 3.8.4; Current Condition C (Revised and Renumbered as Condition E); Change (6)

Current Units 1 and 2, TS 3.8.4, Condition C, states:

C. One DG DC electrical power subsystem inoperable.

Revised and renumbered Units 1 and 2, TS 3.8.4, Condition E, would state:

E. One DG DC train inoperable for reasons other than Condition D.

Current Units 1 and 2, TS 3.8.4, Required Action C.1, states:

C.1 Restore DG DC electrical power subsystem to OPERABLE status.

Revised and renumbered Units 1 and 2, TS 3.8.4, Required Action E.1, would state:

E.1 Restore DG DC train to OPERABLE status.

The CT for the revised and renumbered Units 1 and 2, TS 3.8.4, Required Action E.1, would remain unchanged and would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ."

Evaluation of Units 1 and 2, TS 3.8.4, Current Condition C (Revised and Renumbered as Condition E), Change (6)

Current Condition C, which applies when one DG DC electrical power subsystem (e.g.,

inoperable battery(ies) and/or inoperable battery charger(s)) is inoperable, would be revised and renumbered as Condition E. Current Required Action C.1 would be revised and renumbered as Required Action E.1 with the same CT of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The NRC staff finds that the renumbering of Condition C and Required Action C.1 as Condition E and Required Action E.1, respectively, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered Condition E would state, "One DG DC train inoperable for reasons other than (new) Condition D." The statement "for reasons other than Condition D" excludes the new Condition D (from Section 3.2.1.5 of this SE) from the revised and renumbered Condition E because the new Condition D will address an inoperable DG battery charger.

In its June 7, 2019, and September 4, 2019, letters, the licensee stated that the DG DC electrical power subsystems support the DGs that are arranged in redundant trains; accordingly, the reference to "DG DC electrical power subsystem" in the revised and renumbered Condition E is changed to "DG DC train" to be consistent with the terminology used for the arrangement of the DGs. The licensee also explained that two DG DC electrical power subsystems are associated with a DG DC train, and if one or two of the DG DC electrical power subsystems in a train is (are) inoperable, that train will be incapable of performing its safety function and must rely on the redundant train to mitigate an event. Since a subsequent failure of the DG DC electrical power subsystem(s) in the redundant train could result in a loss of the minimum required ESF function, continued power operation is limited to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to allow time for restoring the inoperable DG DC train to operable status (revised and renumbered Required Action E.1 ).

Based on the above, the NRC staff concludes that the proposed TS 3.8.4 revised and renumbered Condition E with its associated required action and CT provide acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.1. 7 Watts Bar, Units 1 and 2, TS 3.8.4, Current Condition D (Revised and Renumbered as Condition F), Change (7)

Current Units 1 and 2, TS 3.8.4, Condition D, states:

D. Required Action and Associated Completion Time of Condition C not met.

Revised and renumbered Units 1 and 2, TS 3.8.4, Condition F, would state:

F. Required Action and associated Completion Time of Condition Dor E not met.

OR One or more DG DC battery charger(s) in redundant trains inoperable.

Current Units 1 and 2, TS 3.8.4, Required Action D.1, states:

D.1 Declare associated DG inoperable.

Revised and renumbered Units 1 and 2, TS 3.8.4, Required Action F.1, would state:

F.1 Declare associated DG( s) inoperable.

The CTs for the revised and renumbered Units 1 and 2, TS 3.8.4, Required Actions F.1, would remain unchanged and would state "Immediately."

Evaluation of Units 1 and 2, TS 3.8.4, Current Condition D (Revised and Renumbered as Condition F), Change (7)

Current Condition D is specific to Watts Bar. The current Condition D would be renumbered as Condition F and revised by replacing the Condition "C" in the statement with "D or E," and by adding a new condition for inoperable DG DC charger in redundant trains. Current Required Action D.1 would be renumbered as Required Action F.1 with the same CT of "Immediately."

The NRC staff finds that the renumbering of Condition D and Required Action D.1 as Condition F and Required Action F.1, respectively, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered Condition F would have two conditions joined by an "OR" connector so that either one of them would apply. The first condition of the revised and renumbered Condition F would state, "Required Action and associated Completion Time of Condition D or E not met." Both the new Condition D (from Section 3.2.1.5 of this SE) and the revised and renumbered Condition E ( current Condition C) pertain to an inoperable DG DC electrical power subsystem. If the DG DC electrical power subsystem cannot be restored to operable status within the required CTs (revised and renumbered Condition F), the affected DG may not be able to perform its intended function, as the DG DC subsystem provides the control power and field flash power from either the battery or the battery charger for DG starting and operation. Thus, Required Action D.1 (renumbered as Required Action F.1) requires the DG to be declared inoperable "immediately" and the applicable conditions and required actions in TS 3.8.1, "AC Sources - Operating," to be entered. The NRC staff finds that the first condition of the revised and renumbered Condition F with associated required action and CT are consistent with the Watts Bar current TS requirements for an inoperable DG DC electrical power subsystem, and are, therefore, acceptable.

In its September 4, 2019, letter, the licensee proposed to add a second condition, which is a new plant-specific condition and is out of scope of TSTF-500, Revision 2, to the revised and renumbered Condition F. The proposed second condition of the revised and renumbered Condition F would state, "One or more inoperable DG DC battery charger(s) in redundant trains inoperable." The licensee stated that this proposed change will align the required actions for inoperable DG DC battery charger( s) in redundant trains to the required actions specified for the affected DG(s). If the DG battery chargers in redundant trains were inoperable, the affected DGs in the redundant trains might not be able to perform their safety functions, and loss of function would be possible for the DGs. The renumbered Required Action F.1 will declare the affected DG(s) in the redundant trains inoperable immediately. This declaration will require entry into TS 3.8.1, "AC Sources - Operating," Condition F, which applies to inoperable DG(s) in redundant trains to restore the inoperable DG(s) in one train to operable status within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

The NRC staff finds that the proposed second condition of the revised and renumbered Condition F with associated Required Action F.1 and CT for inoperable DG battery chargers in redundant trains are consistent with the Watts Bar TS requirements for the condition in which the inoperable DG DC subsystems may render the associated DGs incapable of performing their safety functions, and are, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed TS 3.8.4 revised and renumbered Condition F with its associated required action and CT provide acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.1.8 Units 1 and 2, TS 3.8.4, Current SR 3.8.4.1 (Revised), Change (8)

Current Units 1 and 2, SR 3.8.4.1, states:

SR 3.8.4.1 Verify vital battery terminal voltage is .:: 128 V ( 132 V for vital battery V) on float charge.

Revised Units 1 and 2, SR 3.8.4.1, would state:

SR 3.8.4.1 Verify vital battery terminal voltage is greater than or equal to the minimum established float voltage.

The frequency for revised SR 3.8.4.1 would remain unchanged and would state "7 days."

Evaluation of Units 1 and 2, TS 3.8.4, Current SR 3.8.4.1 (Revised), Change (8)

Current SR 3.8.4.1 would be revised to verify that the battery terminal voltage is greater than or equal to "the minimt,1m established float voltage" instead of the specific limiting value of the float voltage.

The purpose of SR 3.8.4.1 is to verify the vital battery terminal voltage while the vital battery is on a float charge to ensure that the effectiveness of the associated battery charger is not degraded. The battery terminal voltage selected by the battery manufacturer is the minimum float voltage that ensures an optimum charging voltage is applied to the battery. In Enclosure 2 of its September 4, 2019, letter, the licensee stated that the vital battery's float voltage requirements are based on the nominal design voltage of the battery and are consistent with the minimum float voltage established by the battery manufacturer, which is 2.20 volts per cell (vpc) times the number of connected cells or 132 V for a 60-cell vital battery. This minimum established float voltage will maintain the battery plates in a condition that supports optimizing the battery grid life and will ensure that the battery will be capable of providing its designed safety function. In addition, the licensee provided a commitment to include the minimum established design limit for the battery terminal float voltage in the Watts Bar UFSAR, where future changes would be subject to the requirements of 10 CFR 50.59. This provides reasonable assurance that the numerical value for the minimum established vital battery float voltage will be appropriately maintained by the licensee to accurately reflect the design of the Watts Bar vital battery system.

The specific limiting value for the minimum established battery float voltage would be relocated to a licensee-controlled program. In Enclosure 4 of its November 29, 2018, letter, the licensee committed to relocate the monitoring of battery float voltage to the proposed new Battery Monitoring and Maintenance Program in TS 5.7 (see Section 3.2.4.1 of this SE for the NRC

staff's evaluation of the program). The new program would require the provision of the limits on the battery terminal voltage. This will allow the flexibility to monitor and control the minimum established float voltage limit at values directly related to the battery's ability to perform its required safety function. The NRC staff finds the revised SR 3.8.4.1 acceptable since relocating the TS limiting value of the battery's terminal float voltage to a licensee-controlled program will allow adequate monitoring of the battery's ability to perform its safety functions.

Based on the above, the NRC staff concludes that the proposed revised SR 3.8.4.1 meets the10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met, and is, therefore, acceptable.

3.2.1.9 Units 1 and 2, TS 3.8.4, Current SR 3.8.4.2 (Revised), Change (9)

Current Units 1 and 2, SR 3.8.4.2, states:

SR 3.8.4.2 Verify DG battery terminal voltage is .::: 124 V on float charge.

Revised Units 1 and 2, SR 3.8.4.2, would state:

SR 3.8.4.2 Verify DG battery terminal voltage is greater than or equal to the minimum established float voltage.

The frequency for revised SR 3.8.4.2 would remain unchanged and would state "7 days."

Evaluation of Units 1 and 2, TS 3.8.4, Current SR 3.8.4.2 (Revised), Change (9)

Current SR 3.8.4.2 would be revised to verify that the battery terminal voltage is greater than or equal to the "minimum established float voltage" instead of the specific limiting value of the float voltage.

The purpose of SR 3.8.4.2 is to verify the vital battery terminal voltage while the vital battery is on a float charge to ensure that the effectiveness of the associated battery charger is not degraded. The battery terminal voltage selected by the battery manufacturer is the minimum float voltage that ensures an optimum charging voltage is applied to the battery. In Enclosure 2 of its September 4, 2019, letter, the licensee stated that the vital battery's voltage requirements in SR 3.8.4.2 are based on the nominal design voltage of the battery and are consistent with the minimum float voltage established by the battery manufacturer, which is 2.20 vpc times the number of connected cells or 127 .6 V for a 58-cell DG battery. This minimum established float voltage will maintain the battery plates in a condition that supports optimizing the battery grid life and will ensure that the battery can provide its designed safety function. In addition, the licensee provided a commitment to include the minimum established design limit for the battery terminal float voltage into the Watts Bar UFSAR, where future changes would be subject to the requirements of 10 CFR 50.59. This provides reasonable assurance that the numerical value for the minimum established DG battery float voltage will be appropriately maintained by the licensee to accurately reflect the design of the Watts Bar DG battery subsystems.

The specific limiting value for the minimum established battery float voltage would be relocated to a licensee-controlled program. The licensee proposed to relocate the monitoring of battery float voltage to the proposed new Battery Monitoring and Maintenance Program in TS 5.7 (see Section 3.2.4.1 of this SE for the NRC staff's evaluation of the program). The new program

would require the provision of the limits for the battery terminal voltage. This will allow the flexibility to monitor and control the minimum established float voltage limit at values directly related to the battery's ability to perform its required safety function. The NRC staff finds the revised SR 3.8.4.2 acceptable since relocating the TS limiting value of the battery's terminal float voltage to the licensee-controlled program will allow adequate monitoring of the battery's ability to perform its safety functions.

Based on the above, the NRC staff concludes that the proposed revised SR 3.8.4.2 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met, and is, therefore, acceptable.

3.2.1.10 Units 1 and 2, TS 3.8.4, Current SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, 3.8.4.8, 3.8.4.9, and 3.8.4.10 (Relocated), Change ( 10)

Current Units 1 and 2, SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, 3.8.4.8, 3.8.4.9, and 3.8.4.10, state:

SR 3.8.4.5 Verify no visible corrosion at terminals and connectors for the vital batteries.

OR Verify connection resistance for the vital batteries is s 80 E-6 ohm for inter-cell connections, s 50 E-6 ohm for inter-rack connections, s 120 E-6 ohm for inter-tier connections, and s 50 E-6 ohm for terminal connections.

SR 3.8.4.6 Verify no visible corrosion at terminals and connectors for the DG batteries.

OR Verify connection resistance for the DG batteries is s 80 E-6 ohm for inter-cell connections, s 50 E-6 ohm for inter-tier connections, and s 50 E-6 ohm for terminal connections.

SR 3.8.4. 7 Verify battery cells, cell plates, and racks show no visual indication of physical damage or abnormal deterioration.

SR 3.8.4.8 Remove visible terminal corrosion and verify battery cell to cell and terminal connections are coated with anti-corrosion material.

SR 3.8.4.9 Verify connection resistance for the vital batteries is s 80 E-6 ohm for inter-cell connections, s 50 E-6 ohm for inter-rack connections, s 120 E-6 ohm for inter-tier connections, and s 50 E-6 ohm for terminal connections.

SR 3.8.4.10 Verify connection resistance for the DG batteries is s 80 E-6 ohm for inter-cell connections, s 50 E-6 ohm for inter-tier connections, and s 50 E-6 ohm for terminal connections.

The current Units 1 and 2, TS 3.8.6, SRs 3.8.4.5 through 3.8.4.10, and their associated surveillance frequencies, would be relocated.

Evaluation of Units 1 and 2, TS 3.8.4, Current SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, 3.8.4.8, 3.8.4.9, and 3.8.4.10 (Relocated), Change (10)

The proposed changes would relocate the requirements of the SRs 3.8.4.5 and 3.8.4.6 (visual inspection for corrosion or verification of connection resistances), SR 3.8.4.7 (visual inspection for physical damage or abnormal deterioration), SR 3.8.4.8 (removal of visible corrosion and ensuring battery cell-to-cell and terminal connections coated with anti-corrosion material), and SRs 3.8.4.9 and 3.8.4.10 (verification of connection resistances) to a licensee-controlled program. In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to relocate the monitoring of battery physical condition (SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, and 3.8.4.8) and battery connection resistance (SRs 3.8.4.5, 3.8.4.6, 3.8.4.9, and 3.8.4.10) to the proposed new Battery Monitoring and Maintenance Program in TS 5.7.

Visual inspection of the battery terminals (SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, and 3.8.4.8) is an important preventive maintenance practice for maintaining a healthy battery (e.g., the early identification and cleaning of battery terminal corrosion can prevent corrosion from spreading between the post and the connector). However, visual inspection of the battery terminals alone does not provide an indication of a battery's capability to perform its design function.

Furthermore, the preventive maintenance for the batteries and related components are subject to the regulatory requirements of 10 CFR 50.65. The NRC staff finds that the preventive maintenance currently contained in SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, and 3.8.4.8 will be adequately controlled in the new Battery Monitoring and Maintenance Program in TS 5. 7.

Regarding the battery cell connection resistance verification of SRs 3.8.4.5, 3.8.4.6, 3.8.4.9, and 3.8.4.10, the resistance values represent limits at which some actions should be taken, not necessarily when the operability of the battery is in question. Between surveillances, the resistance of each battery inter-cell connection varies independently from all the others. Some of these connection resistance values may be higher or lower than others, and the battery will still be able to perform its function and should not be considered inoperable. In Enclosure 1 of its November 29, 2018, letter, the licensee stated that the inter-cell, inter-rack, inter-tier, and terminal connections resistance limits for the vital and DG batteries, as provided in SRs 3.8.4.5, 3.8.4.6, 3.8.4.9, and 3.8.4.10, are based on the battery vendor's recommendations, apply to the battery's overall connection resistance, and allow for normal degradation while maintaining battery operability.

In general, the plant safety analyses do not assume a specific battery inter-cell connection resistance value but typically assume that the batteries will supply adequate power. Therefore, the key operability issue is the overall battery connection resistance. The overall connection resistance has a direct impact on operability and is adequately determined by completion of the battery service or modified performance discharge tests. The NRC staff finds that the verification of the batteries' connections resistance limits in the current SRs 3.8.4.5, 3.8.4.6, 3.8.4.9, and 3.8.4.10 will be more appropriately controlled under the proposed new Battery Monitoring and Maintenance Program in TS 5. 7.

Based on the above, the NRC staff finds that the proposed relocation of SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, 3.8.4.8, 3.8.4.9, and 3.8.4.10 from TS 3.8.4 into the new Battery Monitoring and Maintenance Program in TS 5. 7 will ensure that the visual inspection and verification of connection resistances for the batteries are appropriately monitored and maintained in accordance with the new program. The NRC staff finds that there is reasonable assurance that safe plant conditions will continue to be maintained, and as such, the proposed change is acceptable.

3.2.1.11 Units 1 and 2, TS 3.8.4, Current SR 3.8.4.11 (Revised and Renumbered as SR 3.8.4.5), Change (11)

Current Units 1 and 2, SR 3.8.4.11, states:

SR 3.8.4.11 --------------------------------------N()TE:-----------------------------------------

This Surveillance is normally not performed in M()DE: 1, 2, 3, or 4.

However, credit may be taken for unplanned events that satisfy this SR.

Verify each vital battery charger is capable of recharging its associated battery from a service or capacity discharge test while supplying normal loads.

()R Verify each vital battery charger is capable of operating for .:: 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months at current limit 220 - 250 amps.

Revised and renumbered Units 1 and 2, SR 3.8.4.5, would state:

SR 3.8.4.5 Verify each vital battery charger supplies .:: 200 amps at greater than or equal to the minimum established float voltage for

.:: 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

()R Verify each vital battery charger can recharge the battery to the fully charged state within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months while supplying the largest combined demands of the various continuous steady state loads, after a battery discharge to the bounding design basis event discharge state.

The frequency for the revised and renumbered Units 1 and 2, SR 3.8.4.5, would remain unchanged and would state "18 months."

E:valuation of Units 1 and 2, TS 3.8.4, Current SR 3.8.4.11 (Revised and Renumbered as SR 3.8.4.5), Change (11)

Current SR 3.8.4.11 verifies the design capacity of each vital battery charger based on the criteria for the charger's current limit amps or capability requirements. The proposed change

would revise SR 3.8.4.11 by replacing the criteria for the battery charger's current limit amps with its rated amps and the minimum established float voltage and by modifying the criteria for the charger's capability requirements.

The current SR 3.8.4.11 would be renumbered as SR 3.8.4.5. As discussed in Section 3.2.1.10 of this SE, the current SRs 3.8.4.5 through 3.8.4.10 will be relocated from TS 3.8.4. The NRC staff finds that the renumbering of SR 3.8.4.11 as SR 3.8.4.5 is consistent with the preceding changes to TS 3.8.4, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered SR 3.8.4.5 would provide two options. The first option requires that each battery charger be capable of supplying greater than or equal to 200 amps at greater than or equal to the minimum established float voltage for greater than or equal to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . The amps requirements are based on the output rating of the chargers. The voltage requirements are based on the battery charger voltage level after a response to a loss of AC power. The minimum float voltage is established by battery manufacturers to provide the optimum charge on the battery and to maintain the battery plates in a condition that supports maintaining the grid life. Maintaining this voltage limit ensures that the battery can provide its designed safety function. The value for the minimum established float voltage (132 V) would be relocated to the proposed new Battery Monitoring and Maintenance Program in TS 5.7. In addition, the current SR 3.8.4.11 tests the vital battery charger operation for a period greater than or equal to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . The NRC staff finds that the first option testing criterion of the revised and renumbered SR 3.8.4.5 will verify the design capacity of the vital battery charger, as required by the current SR 3.8.4.11, and is, therefore, acceptable.

The second option of the renumbered SR 3.8.4.5 would require that each battery charger be capable of recharging the battery to the fully charged state within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , while supplying the largest combined demands of the various continuous steady state loads after a battery discharge to the bounding design-basis event discharge state. This option will provide an alternate method for verifying the design capacity of the vital battery chargers. This test would be performed following a battery service test or capacity discharge test. The level of loading required for this test may not be available following the battery service test and will need to be supplemented with additional loads. In Watts Bar UFSAR Section 8.3.2, the licensee stated that each vital battery charger can recharge a battery from the design discharged condition in approximately 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months , while supplying normal loads following a 4-hour AC power outage. The NRC staff finds that the second option for the revised and renumbered SR 3.8.4.5 will confirm the vital battery charger design capacity, and is, therefore, acceptable.

The note, "This Surveillance is normally not performed in MODE 1, 2, 3, or 4. However, credit may be taken for unplanned events that satisfy this SR," for current SR 3.8.4.11 will be deleted.

The NRC staff finds the deletion of the note acceptable since the alternate method can be performed in Mode 1, 2, 3, or 4 without affecting plant safety.

Based on the above, the NRC staff concludes that the proposed revised and renumbered SR 3.8.4.5 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met, and is, therefore, acceptable.

3.2.1.12 Watts Bar, Units 1 and 2, TS 3.8.4, Current SR 3.8.4.12 (Revised and Renumbered as SR 3.8.4.6), Change (12)

Current Units 1 and 2, SR 3.8.4.12, states:

SR 3. 8. 4. 12 --------------------------------------NOTE-----------------------------------------

Cred it may be taken for unplanned events that satisfy this SR.

Verify each diesel generator battery charger is capable of recharging its associated battery from a service or capacity discharge test while supplying normal loads.

Revised and renumbered Units 1 and 2, SR 3.8.4.6, would state:

SR 3.8.4.6 --------------------------------------NOTE-----------------------------------------

Credit may be taken for unplanned events that satisfy this SR.

Verify each DG battery charger can recharge the battery to the fully charged state within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months while supplying the largest combined demands of the various continuous steady state loads, after a battery discharge to the bounding design basis event discharge state.

The frequency for the revised and renumbered Units 1 and 2, SR 3.8.4.6, would remain unchanged and'would state "18 months."

Evaluation of Units 1 and 2, TS 3.8.4, Current SR 3.8.4.12 (Revised and Renumbered as SR 3.8.4.6), Change (12)

Current SR 3.8.4.12 verifies the DG battery charger capability to recharge the associated battery from a service or capacity discharge test while supplying normal loads, and its purpose is to verify the design capacity the DG battery charger.

The current SR 3.8.4.12 would be revised and renumbered as SR 3.8.4.6. As discussed in the above Section 3.2.1.11 of this SE, the preceding SR 3.8.4.11 will be renumbered as SR 3.8.4.5.

The NRC staff finds that the renumbering of SR 3.8.4.12 as SR 3.8.4.6 is consistent with the proposed changes to TS 3.8.4, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered SR 3.8.4.6 would require that each DG battery charger be capable of recharging the DG battery to the fully charged state within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , while supplying the largest combined demands of the various continuous steady state loads after a battery discharge to the bounding design-basis event discharge state. This test for the DG battery charger would be performed following the DG battery service test or capacity discharge test.

The level of loading required for this test may not be available following the battery service test and will need to be supplemented with additional loads. The duration of this test may be longer than the charger sizing criteria because the battery recharge is affected by float voltage, temperature, and the exponential decay in charging current. In its letter dated June 7, 2019, the licensee stated that the DG batteries would be expected to be fully recharged in less than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months considering the capacity of the DG battery chargers (rated for 20 amps), the normal

steady state loads (10.41 amps) on a DG battery charger, and the relatively small amount of capacity (66.5 amp-hours) that would be removed from the DG batteries(rated for 192 amp-hours) during a 4-hour SBO event.

Because the DG battery charger can recharge the DG battery to the fully charged state within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , as proposed in the revised and renumbered SR 3.8.4.6, the NRC staff finds that the proposed revised and renumbered SR 3.8.4.6 satisfies the purpose of the current SR 3.8.4.12 to verify the DG battery charger design capacity, and is, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed revised and renumbered SR 3.8.4.6 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met, and is, therefore, acceptable.

3.2.1.13 Watts Bar, Units 1 and 2, TS 3.8.4, Current SR 3.8.4.13 (Revised and Renumbered as SR 3.8.4.7), Change (13)

Current Units 1 and 2, SR 3.8.4.13, states:

SR 3.8.4.13 --------------------------------------N()TES----------------------------------------

1. The modified performance discharge test in SR 3.8.4.14 may be performed in lieu of the service test in SR 3.8.4.13 once per 60 months.

2. This Surveillance is not performed in MODE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is adequate to supply, and maintain in OPERABLE status, the required emergency and any connected nonsafety loads for the design duty cycle when subjected to a battery service test Revised and renumbered Units 1 and 2, SR 3.8.4. 7, would state:

SR 3.8.4.7 --------------------------------------N()TES----------------------------------------

1. The modified performance discharge test in SR 3.8.6. 7 may be performed in lieu of the service test in SR 3.8.4. 7.

2. This Surveillance is not performed in M()DE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is adequate to supply, and maintain in OPERABLE status, the required emergency loads and any

connected nonsafety loads for the design duty cycle when subjected to a battery service test The frequency for the revised and renumbered Units 1 and 2, SR 3.8.4.7, would remain unchanged and would state "18 months."

Evaluation of Units 1 and 2, TS 3.8.4, Current SR 3.8.4.13 (Revised and Renumbered as SR 3.8.4.7), Change (13)

The current SR 3.8.4.13 is modified by a Note 1 that allows the performance of the modified performance discharge test in SR 3.8.4.14 instead of the service test in SR 3.8.4.13. The current SR 3.8.4.13 would be revised by renumbering it as SR 3.8.4. 7 and by modifying current Note 1.

The revised SR 3.8.4.17 would be renumbered as SR 3.8.4.7. As discussed in the above Section 3.2.1.12 of this SE, the preceding SR 3.8.4.12 will be renumbered as SR 3.8.4.6.

Therefore, the NRC staff finds that the renumbering of SR 3.8.4.13 as SR 3.8.4. 7 is consistent with the preceding changes to TS 3.8.4, is editorial in nature, and is, therefore, acceptable.

The current Note 1 would be revised by renumbering SR 3.8.4.13 as SR 3.8.4.7 and SR 3.8.4.14 as SR 3.8.6.7, and by deleting "once per 60 months." As discussed above, SR 3.8.4.13 is being renumbered as SR 3.8.4. 7. The SR 3.8.4.14 would be relocated and renumbered as SR 3.8.6.7 (see Section 3.2.3.22 of this SE for a detailed discussion regarding the renumbered SR 3.8.6. 7). The NRC staff finds that the renumbering of the SRs in Note 1 is consistent with the proposed changes to TS 3.8.4 and, therefore, acceptable. In addition, the deletion of "once per 60 months" in Note 1 would allow the modified performance discharge test to be used in lieu of the service test at any time. In Enclosure 1 of its November 29, 2018, letter, the licensee confirmed that the modified performance discharge test completely encompasses the load profile of the battery service test and adequately confirms the intent of the service test to verify the battery capacity to supply the design-basis load profile. Therefore, the NRC staff finds the elimination of "once per 60 months" acceptable.

Based on the above, the NRC staff concludes that the proposed renumbered SR 3.8.4. 7 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met, and is, therefore, acceptable.

3.2.1.14 Watts Bar, Units 1 and 2, TS 3.8.4, Current SR 3.8.4.14 (Relocated to New SR 3.8.6.7), Change (14)

The proposed change would relocate current SR 3.8.4.14 from TS 3.8.4 to TS 3.8.6 SR 3.8.6. 7.

Current Units 1 and 2, SR 3.8.4.14, states:

SR 3. 8. 4. 14 --------------------------------------NOTE-----------------------------------------

Th is Surveillance is not performed in MODE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is ;:: 80% of the manufacturer's rating when subjected to a performance discharge test or a modified performance discharge test.

The frequencies for current Units 1 and 2, SR 3.8.4.14, state, "60 months" AND "12 months when battery shows degradation or has reached 85% of [the] expected life with capacity

< 100% of manufacturer's rating" AND "24 months when battery has reached 85% of the expected life with capacity ;:: 100% of manufacturer's rating."

Evaluation of Units 1 and 2, TS 3.8.4, Current SR 3.8.4.14 (Deleted and Relocated to SR 3.8.6.7), Change (14)

The licensee proposed relocating the current SR 3.8.4.14 from TS 3.8.4 to new SR 3.8.6. 7 in TS 3.8.6. The purpose of this SR is to demonstrate the operability of the battery; thus, this surveillance is relocated to TS 3.8.6, "Battery Parameters." This change is discussed further in Section 3.2.3.22 of this SE.

3.2.2 TS 3.8.5 (DC Sources - Shutdown) Changes This section addresses the proposed changes to both Units 1 and 2 TS 3.8.5. TS 3.8.5 requirements are similar for both Units 1 and 2, except for the LCO notes. Only the Unit 1 TS 3.8.5 LCO includes a note that allows the substitution of the C-S DG and its associated DC electrical power subsystem for any of the required DGs and their associated DC electrical power subsystems.

In its November 29, 2018, letter, Enclosure 2, the licensee provided the following description of the Units 1 and 2 LCO 3.8.5 requirements:

The 125V Vital DC electrical power subsystems, each vital subsystem channel consisting of a battery bank, associated battery charger, and the corresponding control equipment and interconnecting cabling within the channel; and the DG DC electrical power subsystems, each consisting of a battery, a battery charger, and the corresponding control equipment and interconnecting cabling, are required to be OPERABLE to support required subsystems of the distribution systems required OPERABLE by LCO 3.8.10, "Distribution Systems - Shutdown" and the required DGs required OPERABLE by LCO 3.8.2, "AC Sources -

Shutdown." As a minimum, one vital DC electrical power subsystem (i.e.,

Channels I and Ill, or II and IV) and two DG DC electrical power subsystems (i.e.,

1M and 2A-A or 1B-B and 2B-B) shall be OPERABLE. This ensures the availability of sufficient DC electrical power sources to operate the plant in a safe manner and to mitigate the consequences of postulated events during shutdown (e.g., fuel handling accidents).

The proposed changes to Units 1 and 2 TS 3.8.5 would (1) add a new condition to address the operability of the units' vital DC battery chargers and (2) revise the existing condition and an SR In addition, the Unit 1 LCO 3.8.5 would be revised by modifying the LCO notes.

The proposed changes to TS 3.8.5 LCOs, actions, and SRs for Units 1 and 2 are similar, except the deletion of the Unit 1 TS 3.8.5 LCO note related to the C-S DG. The NRC staff's evaluation below of the proposed changes to TS 3.8.5 is applicable to both Units 1 and 2.

3.2.2.1 Watts Bar, Unit 1, TS 3.8.5, Current LCO 3.8.5 (Revised), Change (1)

Current Unit 1, TS 3.8.5, LCO 3.8.5, states:

LCO 3.8.5 Vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems - Shutdown" and to support the Diesel Generators (DGs) required by LCO 3.8.2, "AC Sources -

Shutdown."

I\IOTES------------------------------------

1. Vital Battery V may be substituted for any of the required vital batteries.

2. The C-S DG and its associated DC electrical power subsystem may be substituted for any of the required DGs and their associated DC electrical power subsystem.

Revised Unit 1, TS 3.8.5, LCO 3.8.5, states:

LCO 3.8.5 Vital DC and Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE to support the DC electrical power distribution subsystem( s) required by LCO 3.8.10, "Distribution Systems - Shutdown" and to support the Diesel Generators (DGs) required by LCO 3.8.2, "AC Sources -

Shutdown."

1\JOTE----- ---------------------------------

Vital Battery V may be substituted for any of the required vital Batteries.

Evaluation of Unit 1, TS 3.8.5, Current LCO 3.8.5 (Revised), Change (1)

The licensee proposed deleting the current Unit 1 TS LCO 3.8.5 note that allows the C-S DG and its associated DC electrical power subsystem to be substituted for any of the required DGs and their associated DC electrical power subsystem. In Enclosure 1 of its l\lovember 29, 2018, letter, the licensee stated that the C-S DG is not being maintained and, therefore, it cannot meet the requirements specified in TS 3.8.1. The I\IRC staff finds that because the current Unit 1 TS LCO 3.8.5 does not require the operability of the C-S DG DC electrical power subsystem, the proposed deletion of the current Unit 1 TS LCO 3.8.5 note is acceptable.

Based on the above, the I\IRC staff finds that the proposed revised Unit 1 TS LCO 3.8.5 is acceptable since the proposed change does not impact the current TS LCO 3.8.5 requirements for the DG DC electrical power subsystems, and the revised Unit 1 TS LCO 3.8.5 will continue to identify the minimum components needed for safe operation of the facility in shutdown modes, as required by 10 CFR 50.36(c)(2)(i).

3.2.2.2 Watts Bar, Units 1 and 2, TS 3.8.5, New Condition A (Added), Change (2)

New Units 1 and 2, TS 3.8.5, Condition A, would state:

A. One or two required vital battery charger(s) on one subsystem inoperable.

The redundant subsystem vital battery and charger( s) OPERABLE.

New Units 1 and 2, TS 3.8.5, Required Actions A.1, A.2, and A.3, would state:

A.1 Restore battery terminal voltage to greater than or equal to the minimum established float voltage.

A.2 Verify battery float current s 2 amps.

A.3 Restore vital battery charger(s) to OPERABLE status.

New CTs for Units 1 and 2, TS 3.8.5, New Required Actions A.1, A.2, and A.3, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ," "Once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ," and "7 days," respectively.

Evaluation of Units 1 and 2, TS 3.8.5, New Condition A (Added), Change (2)

New Condition A would be applicable when one or two required vital battery charger(s) on one subsystem is inoperable and the redundant subsystem vital battery and charger(s) are operable.

Condition A is included in TS 3.8.5 when the plant-specific implementation of TSTF-500, Revision 2, TS 3.8.5 requires both a DC electrical subsystem and its redundant subsystem to be operable. In Enclosure 1 of its November 29, 2018, letter, the licensee stated that the operability of both vital DC electrical power subsystems could be required during a portion of the of the LCO 3.8.5 applicability. According to the TS 3.8.5 Bases, at least one vital DC electrical power train (i.e., Channels I and Ill, or II and IV) is required to be operable to support the vital DC electrical power distribution subsystems required by LCO 3.8.10. In addition, two trains (or redundant trains) of vital DC electrical power distribution subsystems may be required by LCO 3.8.10. In this case, TS LCO 3.8.5 will require both a vital DC electrical power subsystem and its redundant subsystem to be operable to support the redundant trains of vital DC electrical power distribution subsystems in LCO 3.8.1 O; therefore, the NRC staff finds the proposed new Condition A acceptable.

New Required Action A.1 would require the affected vital battery terminal voltage to be restored to greater than or equal to the minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The battery charger, in addition to maintaining the battery operable, supports the recovery of AC power following events such as LOOP or SBO. The 2-hour CT provides an allowance for returning an inoperable charger to operable status or for reestablishing an alternate means (e.g., spare battery charger) of restoring battery terminal voltage to greater than or equal to the minimum established float voltage.

According to Section 8.3.2 of the Watts Bar UFSAR, the 125 V DC vital control power system includes two pairs of spare battery chargers for the four DC channels (one pair for two channels), with each pair of spare chargers mechanically interlocked such that only one charger in each pair can be used at a time. The licensee stated that the spare chargers can be manually connected to the battery boards upon loss of the normal chargers. The Watts Bar UFSAR, Figure 8.1-3, shows that one pair of battery chargers is shared between the DC Channels I and II and the other pair of battery chargers is shared between the DC Channels Ill and IV. Thus, if two vital battery chargers (e.g., chargers in DC Channels I and Ill) are inoperable in one vital DC electrical power subsystem (e.g., Train A) in new Condition A, two spare chargers with one spare charger in each pair (i.e., one spare charger for DC Channel I and one spare charger for DC Channel Ill) will be used to substitute for the two inoperable battery chargers. According to Section 8.3.2 and Figure 8.1-3, all the normal and spare chargers have the same rated capacity of 200 amps. Thus, the spare vital battery charger(s) will be able to restore the affected battery(ies) terminal voltage(s) to greater than or equal to the minimum established float voltage within the 2-hour CT. At the end of the 2-hour CT, a terminal voltage of at least the minimum established float voltage provides indication that the battery is on the exponential charging current portion of its recharging cycle. This provides assurance that the battery can be restored to its fully charged condition from any discharge that might have occurred due to the charger inoperability. The proposed new Required Action A.1 will allow the DC bus to remain energized and the battery discharge to be terminated; therefore, the NRC staff finds the proposed new Required Action A.1 with associated CT acceptable.

New Required Action A.2 would require that the battery float current be verified as less than or equal to 2 amps once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This would indicate that, if the battery had been discharged as the result of the inoperable battery charger, it had been recharged and fully capable of supplying the maximum expected load requirement. In its letter dated June 7, 2019, the licensee stated that the vital batteries would be fully recharged in less than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to less than 2 amps, considering the capacity of the battery chargers (rated for 200 amps) and the relatively small amount of capacity (200 amp-hours) that would be removed from the batteries (rated for 2320 amp-hours) within the 2-hour allowed time to place a battery charger on the battery. If at the expiration of the 12-hour period, the battery float current is greater than 2 amps, then the battery is considered inoperable (see Section 3.2.3.3 of this SE for a more detailed discussion on the 2-amp float current value). The NRC staff finds the proposed new Required Action A.2 and its associated CT acceptable because this verification of float current provides assurance that the battery has sufficient capacity to perform its safety function.

New Required Action A.3 would limit the restoration time for the inoperable battery charger to 7 days. An alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage (e.g. spare battery charger) will be in use during this time. A 7-day CT for an inoperable battery charger is acceptable if an alternate means to charge the batteries is available and is capable of being supplied power from a power source that is independent of the offsite power supply, as described in the UFSAR. In Enclosure 1, Section 2.3, of its November 29, 2018, letter, the licensee stated that the proposed 7-day CT for inoperable vital battery charger(s) is based on the availability of spare charger(s) that are used to substitute for the inoperable charger(s) and can be supplied by the associated DG(s), which is (are) independent of the offsite power supply. In the Watts Bar UFSAR, Section 8.3.2, the licensee stated that the spare chargers, if in service, are automatically loaded on the DGs for a LOOP event. In addition, in Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to include in the Watts Bar UFSAR the minimum requirements for the alternate means (i.e., spare battery charger) that are used to obtain extended battery charger CT (i.e.,

7-day CT), where future changes would be subject to the requirements of 10 CFR 50.59. This

provides additional reasonable assurance that the alternate means (i.e., spare chargers) used to obtain the 7-day CT will be appropriately maintained by the licensee.

The NRC staff finds the proposed new Required Action A.3 within 7-day CT is acceptable because the spare battery chargers provide an alternate means to charge the batteries and are capable of being supplied power from the DGs that are independent of the offsite power supply.

Based on the above, the NRC staff concludes that the proposed TS 3.8.5 new Condition A with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.2.3 Watts Bar, Unit 1, TS 3.8.5, Current Condition A (Revised and Renumbered as Condition B), Change (3)

Current Units 1 and 2, TS 3.8.5, Condition A, states:

A. One or more required vital DC electrical power subsystems inoperable.

Revised and renumbered Units 1 and 2, TS 3.8.5, Condition B, would state:

B. One or more required vital DC electrical power subsystems inoperable for reasons other than Condition A.

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

Current Units 1 and 2, TS 3.8.5, Required Actions A.1.1, A.2.1, A.2.2, A.2.3, and A.2.4, state:

A.1.1 Declare affected required feature(s) inoperable.

OR A.2.1 Suspend CORE ALTERATIONS.

A.2.2 Suspend movement of irradiated fuel assemblies.

A.2.3 Initiate action to suspend operations involving positive reactivity additions.

A.2.4 Initiate action to restore required DC electrical power subsystems to OPERABLE status.

Revised and renumbered Units 1 and 2, TS 3.8.5, Required Actions 8.1.1, 8.2.1, 8.2.2, 8.2.3, and 8.2.4, would state:

8.1.1 Declare affected required feature(s) inoperable.

OR 8.2.1 Suspend CORE ALTERATIONS.

8.2.2 Suspend movement of irradiated fuel assemblies.

8.2.3 Initiate action to suspend operations involving positive reactivity additions.

8.2.4 Initiate action to restore required DC electrical power subsystems to operable status.

The CTs for the revised and renumbered Units 1 and 2, TS 3.8.5, Required Actions 8.1.1, 8.2.1, 8.2.2, 8.2.3, and 8.2.4, would remain unchanged and would state, "Immediately."

Evaluation of Units 1 and 2, TS 3.8.5, Current Condition A (Revised and Renumbered as Condition 8) 1 Change (3)

Current Condition A would be revised and renumbered as Condition 8, and current Required Actions A.1.1, A.2.1, A.2.2, A.2.3, and A.2.4 would be renumbered as 8.1.1, 8.2.1, 8.2.2, 8.2.3, and 8.2.4. The NRC staff finds that the renumbering of Condition A and Required Actions A.1.1, A.2.1, A.2.2, A.2.3, and A.2.4 as Condition 8 and Required Actions 8.1.1, 8.2.1, 8.2.2, and 8.2.4, respectively, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered Condition 8 would state, "One or more required vital DC electrical power subsystems inoperable for reasons other than Condition A or required actions and associated Completion Time of Condition A not met." The new Condition A (from Section 3.2.2.2 of this SE) will address the condition where a required vital DC electrical power subsystem is rendered inoperable due to an inoperable charger. The NRC staff finds the revised and renumbered Condition 8 is acceptable because this change reflects the addition of new Condition A.

The renumbered Required Actions 8.1.1, 8.2.1, 8.2.2, 8.2.3, and 8.2.4 and associated CTs remain the same for the revised and renumbered Condition 8.

If two trains of vital DC subsystems are required by LCO 3.8.10, the remaining subsystem with DC power available may be capable of supporting sufficient systems to allow continuation of core alterations and irradiated fuel movement. Therefore, the option of declaring the required features inoperable with the associated DC power source(s) also inoperable is implemented with restrictions in accordance with the affected required features LCO actions. Otherwise, sufficiently conservative actions are made (i.e., to suspend core alterations, movement of

irradiated fuel assemblies, and operations with a potential for draining the reactor vessel) to minimize the probability of the occurrence of postulated events. Suspension of these activities does not preclude completion of actions to establish a safe, conservative condition. It is further required to initiate action to immediately restore required DC electrical power subsystems to operable status. The restoration of the required DC electrical power subsystems should be completed as quickly as possible in order to minimize the time during which the plant safety systems may be without sufficient power. The CT of immediately is consistent with the required times for actions requiring prompt attention. The NRC staff finds current required actions and associated CTs for the proposed revised and renumbered Condition B acceptable because they are consistent with the current licensing basis for inoperable vital DC electrical power subsystems at shutdown conditions.

Based on the above, the NRC staff concludes that the proposed TS 3.8.5 revised and renumbered Condition B with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.2.4 Watts Bar, Unit 1, TS 3.8.5, Current Condition B (Renumbered as Condition C),

Change (4)

Current Units 1 and 2, TS 3.8.5, Condition B, states:

B. One required DG DC electrical power subsystem inoperable.

Renumbered Units 1 and 2, TS 3.8.5, Condition C, would state:

C. One required DG DC electrical power subsystem inoperable.

Current Units 1 and 2, TS 3.8.5, Required Action B.1, states:

B.1 Declare associated DG inoperable.

Renumbered Units 1 and 2, TS 3.8.5, Required Action C.1, would state:

C.1 Declare associate DG inoperable.

The CT for the renumbered Units 1 and 2, TS 3.8.5, Required Actions C.1, would remain unchanged and would state "Immediately."

Evaluation of Units 1 and 2. TS 3.8.5. Current Condition B (Renumbered as Condition C).

Change (4)

The current Condition B is specific to Watts Bar. The current Condition B and Required

. Action B.1 would be renumbered as Condition C and Required Action C.1, respectively. As discussed in Section 3.2.2.3 of this SE, the current Condition A will be renumbered as Condition B.

The NRC staff finds that the renumbering of Condition B and Required Action B.1 as Condition C and Required Action C.1, respectively, is consistent with the proposed changes to TS 3.8.5, is editorial in nature, and is, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed TS 3.8.5 renumbered Condition C with its associated required action and CT provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.2.5 Watts Bar, Unit 1, TS 3.8.5, Current SR 3.8.5.1 (Revised), Change (5)

Current Units 1 and 2, SR 3.8.5.1, states:

SR 3.8.5.1 --------------------------------------N()TE:-----------------------------------------

The following SRs are not required to be performed: SR 3.8.4.11, SR 3.8.4.12, SR 3.8.4.13, and SR 3.8.4.14.

For DC sources required to be ()PE:RABLE:, the following SRs are applicable:

SR 3.8.4.1 SR 3.8.4.6 SR 3.8.4.11 SR 3.8.4.2 SR 3.8.4.7 SR 3.8.4.12 SR 3.8.4.3 SR 3.8.4.8 SR 3.8.4.13 SR 3.8.4.4 SR 3.8.4.9 SR 3.8.4.14 SR 3.8.4.5 SR 3.8.4.10 Revised Units 1 and 2, SR 3.8.5.1, would state:

SR 3.8.5.1 --------------------------------------N()TE:-----------------------------------------

The following SRs are not required to be performed: SR 3.8.4.5, SR 3.8.4.6, and SR 3.8.4.7.

For DC sources required to be ()PE:RABLE:, the following SRs are applicable:

SR 3.8.4.1 SR 3.8.4.5 SR 3.8.4.2 SR 3.8.4.6 SR 3.8.4.3 SR 3.8.4.7 SR 3.8.4.4 The frequency for revised Units 1 and 2 SR 3.8.5.1 would remain unchanged and would state, "In accordance with applicable SRs."

!::valuation of Units 1 and 2, TS 3.8.5, Current SR 3.8.5.1 (Revised), Change (5)

The current SR 3.8.5.1 would be revised by modifying the applicable SRs from SR 3.8.4.1 -

SR 3.8.4.14 to SR 3.8.4.1 -SR 3.8.4.7.

As discussed in Sections 3.2.1.10 1 - 3.2.1.14 of this SE:, (1) SRs 3.8.4.5, 3.8.4.6, 3.8.4.7, 3.8.4.8, 3.8.4.9, and 3.8.4.10 will be relocated from TS 3.8.4; (2) SRs 3.8.4.11, 3.8.4.12, and 3.8.4.13 will be revised and renumbered as SRs 3.8.4.5, 3.8.4.6, and 3.8.4. 7, respectively; and (3) SR 3.8.4.14 will be relocated to TS 3.8.6 and renumbered as SR 3.8.6.6. The NRC staff finds that the proposed list of applicable SRs 3.8.4.1 - 3.8.4. 7 referenced in the revised SR 3.8.5.1 is consistent with the proposed changes to TS 3.8.4, and is, therefore, acceptable.

The current note in the current SR 3.8.5.1 allows the current SR 3.8.4.11 (vital battery charger capacity test), SR 3.8.4.12 (DG battery charger capacity test), SR 3.8.4.13 (battery service test),

and SR 3.8.4.14 not to be performed. According to TS B 3.8.5, the intent of the current note is to preclude requiring the operable DC sources (battery and battery chargers) from being discharged below their capability to provide the required power supply or from being rendered inoperable during the performance of SRs for the battery charger capacity tests and the battery service test. Nevertheless, these SRs must still be capable of being met.

The current note would be revised by renumbering SR 3.8.4.11 as SR 3.8.4.5, SR 3.8.4.12 as SR 3.8.4.6, and SR 3.8.4.13 as SR 3.8.4. 7, and by deleting SR 3.8.4.14. As discussed above, renumbering of SRs 3.8.4.5, 3.8.4.6, and 3.8.4. 7 is consistent with the proposed changes to TS 3.8.4, and the deletion of SR 3.8.4.14 from the revised note is consistent with the proposed relocation of SR 3.8.4.14 to TS 3.8.6.

The revised note in the revised SR 3.8.5.1 would not require the performance of the renumbered SR 3.8.4.5 (vital battery charger capacity test), SR 3.8.4.6 (DG battery charger capacity test), and SR 3.8.4.7 (battery service test) in TS 3.8.5 (shutdown conditions). The renumbered SRs 3.8.4.5 and 3.8.4.6 may be performed during normal operation in TS 3.8.4 without affecting plant safety, and credit may be taken for unplanned events that satisfy the renumbered SR 3.8.4. 7 during normal operation in TS 3.8.4. Since the renumbered SRs 3.8.4.5, 3.8.4.6, and 3.8.4. 7 can be performed during operating conditions, the revised note will prevent requiring the operable DC sources from being discharged below their capability to provide the required power supply or from being rendered inoperable during the performance of these SRs at shutdown (TS 3.8.5). The NRC staff finds that the revised note for the revised SR 3.8.5.1 satisfies the intent of the current note and is acceptable.

In summary, the NRC staff finds the proposed revised SR 3.8.5.1 acceptable because the proposed changes to the current SR 3.8.5.1 are consistent with the proposed changes to TS 3.8.4.

Based on the above, the NRC staff concludes that the proposed revised SR 3.8.5.1 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met and is acceptable.

3.2.3 TS 3.8.6 (Battery Parameters) Changes The licensee proposed replacing the battery-specific gravity monitoring with the float current monitoring for determining the stated charge (OPERABILITY} of the battery. The licensee also proposed revising the current TS 3.8.6 title, LCO, required actions, and SRs; deleting Table 3.8.6-1, "Battery Cell Parameter Requirements"; and relocating select SRs to the new TS 5.7.2.22, "Battery Monitoring and Maintenance Program."

In its September 4, 2019, letter, the licensee stated that two DG DC electrical power subsystems (each subsystem includes a battery) are associated with each DG DC electrical power train.

The current TS 3.8.6 and the proposed changes to TS 3.8.6 are similar for both Units 1 and 2.

Therefore, the following NRC staff evaluation of the proposed changes to TS 3.8.6 is applicable to both Units 1 and 2.

3.2.3.1 Watts Bar, Units 1 and 2, TS 3.8.6, Title (Revised), Change (1)

The proposed change would revise the title of TS 3.8.6 from "Battery Cell Parameters" to "Battery Parameters."

Evaluation of Units 1 and 2, TS 3.8.6, Title (Revised), Change (1)

The current TS 3.8.6 specifies the requirements for battery cell parameters. The revised TS 3.8.6 would provide requirements for battery cell parameters and battery float currents.

Since the revised TS 3.8.6 will address battery parameters (cell parameters and float currents),

the NRC staff finds that deleting the term "Cell" in the title of TS 3.8.6 is editorial in nature, and is, therefore, acceptable.

3.2.3.2 Watts Bar, Units 1 and 2, TS 3.8.6, Table 3.8.6-1, "Battery Cell Parameter Requirements" (Deleted), Change (2)

The current TS Table 3.8.6-1, "Battery Cell Parameters Requirements," specifies the requirements (Categories A, B, and C limits) for the battery cell parameters (electrolyte level, float voltage, and specific gravity). The proposed change would delete TS Table 3.8.6-1 and relocate the table requirements to proposed new SRs in TS 3.8.6 and the new Battery Monitoring and Maintenance Program in TS 5. 7.

Evaluation of Units 1 and 2, TS 3.8.6, Table 3.8.6-1 (Deleted), Change (2)

The TS Table 3.8.6-1, Category A, defines the normal limits for each designated pilot cell; Category B defines the normal limits for each connected cell; and Category C defines the allowable limits for each connected cell.

In Enclosure 1 of its November 29, 2018, letter, Section 1.0, "Description," the licensee proposed to relocate Table 3.8.6-1 to the proposed new Battery Monitoring and Maintenance Program in TS 5. 7 (see Section 3.2.4.1 of this SE for the NRC staff's evaluation of the program).

In its letter dated June 7, 2019, the licensee stated that the battery parameters (electrolyte, float voltage, specific gravity) will be relocated at their current Categories A, B, and C levels to the proposed new program in TS 5. 7. The licensee further stated that the battery cell parameters within the program will be controlled in accordance with the program and actions to restore deficient values of any of the parameters will be implemented in accordance with the TVA corrective action program.

The Category A and B limits for battery electrolyte level, float voltage, and specific gravity represent appropriate monitoring levels and appropriate preventive maintenance levels for long-term battery quality and extended battery life. The Category C limits for battery float voltage and electrolyte level will be addressed in the proposed TS 3.8.6, new Conditions A (vital battery float voltage), C (DG battery float voltage), and E (electrolyte level) (see Sections 3.2.3.6, 3.2.3.8, and 3.2.3.10 of this SE for the NRC staff's evaluation of the proposed new TS 3.8.6 Conditions A, C, and E). The Category C limits for specific gravity used for verifying battery state of charge will be replaced with float current monitoring in the proposed new SR 3.8.6.1 (vital battery float current) and SR 3.8.6.2 (DG battery float current) (see Sections 3.2.3.16 and 3.2.3.17 of this SE for the NRC staff's evaluation of the proposed new SRs 3.8.6.1 and 3.8.6.2). In addition, the proposed new SRs 3.8.6.3, 3.8.6.4, and 3.8.6.6 will require monitoring of battery pilot cell float voltage, connected cell electrolyte level, and

connected cell float voltage, respectively (see Sections 3.2.3.18, 3.2.3.19, and 3.2.3.21 of this SE for the NRC staff's evaluation of the proposed new SRs 3.8.6.3, 3.8.6.4, and 3.8.6.6).

The NRC staff finds the relocation of the Category A, B, and C limits to the Battery Monitoring and Maintenance Program acceptable because (1) Category A and B limits are maintenance levels, (2) Category C limits will be addressed in proposed new SRs and conditions, and specific gravity measurement criteria are being replaced with float current monitoring, and (3) the licensee provided assurance that these battery parameter values will continue to be controlled in accordance with the program, and that actions to restore deficient values of any of the parameters will be implemented in accordance with the licensee's corrective action program.

Based on the above, the NRC staff concludes that the proposed elimination of TS Table 3.8.6-1 ensures the battery parameters (maintenance, testing, and monitoring) will be appropriately monitored and maintained in accordance with the new Battery Monitoring and Maintenance Program in TS 5. 7 and the new requirements in TS 3.8.6. Therefore, the NRC staff finds that there is assurance that safe plant conditions will continue to be maintained, and as such, the proposed deletion of TS Table 3.8.6-1 is acceptable.

3.2.3.3 Watts Bar, Units 1 and 2, TS 3.8.6, Float Current Monitoring (Added to Replace Specific Gravity Measurement), Change (3)

The proposed change would replace requirements to measure specific gravity to determine the battery state of charge with requirements to monitor battery float current and would relocate requirements to obtain specific gravity readings to the proposed new Battery Monitoring and Maintenance Program specified in TS 5.7.

Evaluation of Units 1 and 2, TS 3.8.6, Float Current Monitoring (Added to Replace Specific Gravity Measurement), Change (3)

Currently battery cell-specific gravity verification is required by existing SRs 3.8.6.1 and 3.8.6.2 and TS 3.8.6 Condition A based on the Category A, B, and C values of current TS Table 3.8.6-1. The Category C specific gravity values are the allowable values for each battery connected cell.

The licensee proposed replacing the requirement for monitoring the specific gravity to determine the battery state of charge with the requirement for monitoring the battery's float current. Float current monitoring is recognized by the industry as being a more direct method for determining battery state of charge than specific gravity monitoring. In Enclosure 5 of its November 29, 2018, letter, the licensee provided letters dated May 30, 2013, and February 23, 2018, from C&D Technologies, Inc, the manufacturer of the Watts Bar Class 1E batteries (vital and DG batteries), verifying the acceptability of using float current measurement as a reliable indication of the batteries' state of charge for the life of the batteries.

The licensee proposed a float current of 2 amps for the vital batteries and 1 amp for the DG batteries. In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include how a 2 percent design margin for the vital and DG batteries corresponds to a 2-amp float current value for the vital batteries and a 1-amp float current value for the DG batteries, indicating that the batteries are at least 98 percent charged.

The NRC staff requested the licensee to explain how maintaining the 2 percent design margin for the vital and DG batteries will ensure that the batteries are fully charged (i.e., capable of

performing their design functions). In its letter dated June 7, 2019, the licensee stated that it verified via the vital and DG battery manufacturers that a charging current of less than or equal to 2 amps for the vital batteries and less than or equal to 1 amp for the DG batteries indicate that the batteries are at least 98 percent charged. Therefore, maintaining an additional 2 percent design margin in the battery sizing calculation is needed to ensure that 100 percent battery capacity is available once the charging current is 2 amps or less for the vital batteries and 1 amp or less for the DG batteries. The licensee stated that this is equivalent to the vital and DG batteries being 100 percent charged because the battery sizing calculation ensures that the batteries can perform their safety-related functions during a design-basis event.

The NRC staff finds that ( 1) the licensee's verification of the battery manufacturer specifications regarding the use of the float current measurement to determine the batteries' state of charge, and (2) the addition of 2 percent design margin to the batteries' sizing to ensure that the batteries can perform their safety functions, as will be described in the Watts Bar UFSAR, provide adequate assurance that replacing the specific gravity measurements with the float current monitoring will not impact the ability to accurately determine the operability of the batteries. The NRC staff concludes that the proposed float current monitoring is a suitable replacement for the specific gravity monitoring when used to determine the state of charge of the batteries.

The requirements for monitoring the float current are provided in the proposed new SR 3.8.6.1 and SR 3.8.6.2 (see Sections 3.2.3.16 and 3.2.3.17 of this SE for the NRC staff's evaluation of the proposed new SRs 3.8.6.1 and 3.8.6.2, respectively). In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to verify that the measuring equipment that will be used to monitor float current under the proposed new SRs 3.8.6.1 and 3.8.6.2 will have the necessary accuracy and capability to measure electrical currents in the expected range.

Specific gravity monitoring is appropriate for troubleshooting activities and for periodic trending of the battery's state of health. The licensee will continue taking and trending specific gravity measurements during maintenance and testing activities prior to performing a battery service test or battery modified performance discharge test in accordance with the new proposed Battery Monitoring and Maintenance Program in TS 5.7.

Based on the above, the NRC staff concludes that the proposed float current monitoring meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met, and is, therefore, acceptable.

3.2.3.4 Watts Bar, Units 1 and 2, TS 3.8.6, Current LCO 3.8.6 (Revised), Change (4)

Current Units 1 and 2, LCO 3.8.6, states:

LCO 3.8.6 Battery cell parameters for 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within the limits of Table 3.8.6-1.

Revised Units 1 and 2, LCO 3.8.6, would state:

LCO 3.8.6 Battery parameters for Train A and Train B electrical power subsystem 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within limits.

Evaluation of Units 1 and 2, TS 3.8.6, Current LCO 3.8.6 (Revised), Change (4)

Current LCO 3.8.6 requires that the battery cell parameters for 125 V vital batteries and 125 V DG batteries be within limits. The LCO 3.8.6 would be revised by adding the term "Train A and Train B electrical power subsystem" and by deleting the term "cell" and the reference to Table 3.8.6-1. In Enclosure 6 of its November 29, 2018, letter, and Enclosure 2 of its September 4, 2019, letter, the licensee stated that the 125 V DC vital power system, including the 125 V vital batteries is arranged in the Train A and Train B vital DC electrical power subsystem. In its June 7, 2019, letter, the licensee stated that the DG DC subsystems, including the 125 V DG batteries, are associated with Train A and Train B of the DGs. Since the 125 V vital batteries and 125 V DG batteries are aligned to Train A and Train B electrical power subsystems, the NRC staff finds that adding the term "Train A and Train B electrical power subsystem" to the LCO 3.8.6 statement does not change the current requirements of LCO 3.8.6, is editorial in nature, and is, therefore, acceptable. In addition, since the term "cell" and Table 3.8.6-1 will be deleted from TS 3.8.6 (see Sections 3.2.3.1 and 3.2.3.2 of this SE for the NRC staff's evaluation of the proposed deletions), the NRC staff finds that deleting the term "cell" and the reference to Table 3.8.6-1 from LCO 3.8.6 is consistent with the proposed changes to TS 3.8.6 and is, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed revised Units 1 and 2 LCOs 3.8.6 are acceptable and will continue to meet the requirements of 10 CFR 50.36(c)(2) since the proposed changes are editorial in nature and do not change the current requirements of the Units 1 and 2 LCOs 3.8.6.

3.2.3.5 Watts Bar, Units 1 and 2, TS 3.8.6, Current Condition A (Deleted), Change (5)

Current Units 1 and 2, TS 3.8.6, Condition A, states:

A. One or more batteries with one or more battery cell parameters not within Category A or B limits.

Current Units 1 and 2, TS 3.8.6, Required Actions A.1, A.2, and A.3, state:

A.1 Verify pilot cells electrolyte level and float voltage meet Table 3.8.6-1 '

Category C limits.

A.2 Verify battery cell parameters meet Table 3.8.6-1 Category C limits.

A.3 Restore battery cell parameters to Category A and B limits of Table 3.8.6-1.

The current CTs to be deleted are "1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months ," "24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months AND Once per 7 days thereafter," and "31 days," for Required Actions A.1, A.2, and A.3, respectively.

Evaluation of Units 1 and 2, TS 3.8.6, Current Condition A (Deleted), Change (5)

The proposed change would delete current Condition A with its associated required actions and CTs. The current Condition A references the battery parameter limits in the Table 3.8.6-1. As discussed in Section 3.2.3.2 of this SE, Table 3.8.6-1 will be deleted from TS 3.8.6. The NRC staff finds that the removal of the current Condition A with its associated required actions and CTs from TS 3.8.6 is consistent with the elimination of TS Table 3.8.6-1, and is, therefore, acceptable.

3.2.3.6 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition A (Added), Change (6)

New Units 1 and 2, TS 3.8.6, Condition A, would state:

A. One or two required vital battery(ies) on one subsystem with one or more battery cells float voltage< 2.07 V.

f'Jew Units 1 and 2, TS 3.8.6, Required Actions A.1, A.2, and A.3, would state:

A.1 Perform SR 3.8.4.1.

A.2 Perform SR 3.8.6.1.

A.3 Restore affected cell voltage~ 2.07 V.

New CTs for Units 1 and 2, TS 3.8.6, Required Actions A 1, A.2, and A.3, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ,"

"2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ," and "24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ," respectively.

Evaluation of Units 1 and 2, TS 3.8.6, New Condition A (Added), Change (6)

The proposed new TS 3.8.6 Condition A would address the required vital battery(ies) in one subsystem with cell(s) float voltage less than 2.07 V. In Enclosure 2 of its September 4, 2019, letter, the licensee stated that the vital battery cells are of flooded lead acid construction with an open circuit voltage of 2.063 vpc, which is maintained when the cell is not charging or discharging. A battery cell voltage below the open circuit cell voltage indicates that the cell is discharging. The proposed battery cell float voltage limit of 2.07 V is greater than the actual vital battery cell open circuit float voltage of 2.063 V. This indicates that the battery cell will not discharge at 2.07 V float voltage. As proposed in new Condition A, the vital battery cell float voltage less than 2.07 V would indicate a partial discharge of the battery cell.

New Condition A would contain remedial measures (required actions) for the condition of a degraded vital battery cell. The proposed new Required Actions A.1 and A.2 would require the licensee to verify that, within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , (a) the battery terminal voltage is greater than or equal to the minimum established float voltage (revised SR 3.8.4.1), and (b) each battery's float current is less than or equal to 2 amps (new SR 3.8.6.1 ), respectively (see Sections 3.2.1.8 and 3.2.3.16 of this SE for the NRC staff's evaluation of the proposed revised SR 3.8.4.1 and new SR 3.8.6.1, respectively). These actions will ensure that there is still sufficient battery capacity to perform the intended function so that the affected battery will not be required to be

considered inoperable solely because of one or more cells float voltage less than 2.07 V.

Therefore, new Required Action A.3 would allow continued operation for a limited period up to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for restoring the affected cell(s) voltage to greater than or equal to 2.07 V. The NRC staff finds that the proposed Required Actions A.1, A.2, and A.3 with the associated CTs are reasonable and are, therefore, acceptable.

In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include the minimum established design limit for battery terminal float voltage. Future changes to this value would be subject to the requirements of 10 CFR 50.59.

This provides reasonable assurance that the value of the battery terminal float voltage will be appropriately maintained by the licensee to reflect accurately the design of the vital batteries.

Based on the above, the NRC staff concludes that the proposed TS 3.8.6 new Condition A with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3. 7 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition B (Added), Change (7)

New Units 1 and 2, TS 3.8.6, Condition B, would state:

B. One or two required vital battery(ies) on one subsystem with float current > 2 amps.

New Units 1 and 2 TS, 3.8.6, Required Actions B.1 and B.2, would state:

B.1 Perform SR 3.8.4.1.

B.2 Restore vital battery float current to s 2 amps.

New CTs for Units 1 and 2 TS 3.8.6, Required Actions B.1 and B.2, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months " and "12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ," respectively.

Evaluation of Units 1 and 2, TS 3.8.6, New Condition B (Added), Change (7)

The proposed new Condition B would address the required vital battery(ies) in one subsystem with float current greater than 2 amps. The battery float current greater than 2 amps indicates that a partial discharge of the battery has occurred. The discharge in battery may be due to a temporary loss of a battery charger or possibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity.

The proposed new Required Action B.1 would verify within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months that the required vital battery terminal voltage is greater than or equal to the minimum established float voltage (revised SR 3.8.4.1 ), thus confirming battery charger operability. If the terminal voltage is satisfactory, the proposed new Required Action B.2 would ensure that the affected vital battery float current is restored to less than 2 amps within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This would confirm that the affected vital battery had been fully recharged from any discharge that might have occurred. In its letter dated June 7, 2019, the licensee stated that the vital batteries would be fully recharged in less than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to less than 2 amps, considering the capacity of the vital battery chargers (rated for 200 amps), the normal steady state loads ( 100 amps) on the vital battery chargers, and the

relatively small amount of capacity (200 amp-hours) that would be removed from the batteries (rated for 2,320 amp-hours) within the 2-hour allowed time to place a battery charger on the battery. Restoring the affected required vital battery to its fully charged state provides the assurance that the battery has sufficient capacity to perform its safety function.

If the vital battery's terminal voltage is found to be less than the minimum established float voltage, it indicates that the vital battery charger is either inoperable or is operating in the current limit mode. If the vital battery charger is operating in the current limit mode for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , it indicates that the vital battery has been substantially discharged and likely cannot perform its required design functions. In this case, the proposed new TS 3.8.6 Condition I would be entered.

The NRC staff concludes that, based on the above discussion, the proposed TS 3.8.6 new Condition B with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.8 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition C (Added), Change (8)

New Units 1 and 2, TS 3.8.6, Condition C, would state:

C. One or two DG battery(ies) on one train with one or more battery cells float voltage < 2.07 V.

New Units 1 and 2, TS 3.8.6, Required Actions C.1, C.2, and C.3, would state:

C.1 Perform SR 3.8.4.2.

C.2 Perform SR 3.8.6.2.

C.3 Restore affected cell voltage~ 2.07 V.

New CTs for Units 1 and 2, TS 3.8.6, Required Actions C.1, C.2, and C.3, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ,"

"2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ," and "24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ," respectively.

Evaluation of Units 1 and 2, TS 3.8.6, New Condition C (Added), Change (8)

The proposed new TS 3.8.6 Condition C would address the DG battery(ies) on one train with cell(s) float voltage less than 2.07 V. According to current Table 3.8.6-1 Category C allowable value, a battery cell float voltage is not allowed to be equal to 2.07 V. In its letter dated June 7, 2019, the licensee stated that the proposed battery cell float voltage limit of 2.07 Vis based on the nominal open circuit cell voltage of 2.06 V for the DG battery cells and the fact that a cell float voltage greater than the open circuit voltage is sufficient to prevent discharge of the floating cell. The proposed new Condition C would contain remedial measures (required actions) for the condition of a degraded DG battery cell with float voltage less than 2.07 V.

The proposed new Required Actions C.1 and C.2 would require the licensee to verify that, within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , (a) the battery terminal voltage is greater than or equal to the minimum established

float voltage (revised SR 3.8.4.2), and (b) each battery's float current is less than or equal to 2 amps (new SR 3.8.6.2), respectively (see Sections 3.2.1.9 and 3.2.3.17 of this SE for the NRC staff's evaluation of the proposed revised SR 3.8.4.2 and the new SR 3.8.6.2, respectively).

These actions will ensure that there is still sufficient battery capacity to perform the intended function so that the affected battery will not be required to be considered inoperable solely as a result of one or more cells float voltage less than 2.07 V. Therefore, the new Required Action C.3 would allow continued operation for a limited period up to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for restoring the affected cell(s) voltage to greater than or equal to 2.07 V. The NRC staff finds the proposed Required Actions C.1 and C.2 with the associated CTs are reasonable and, therefore, acceptable.

In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include the minimum established design limit for battery terminal float voltage. Future changes to this value would be subject to the requirements of 10 CFR 50.59.

This provides reasonable assurance that the value of the battery terminal float voltage will be appropriately maintained by the licensee to accurately reflect the design of the DG batteries.

Based on the above, the NRC staff concludes that the proposed TS 3.8.6 new Condition C with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.9 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition D (Added), Change (9)

New Units 1 and 2, TS 3.8.6, Condition D, would state:

D. One or two DG battery(ies) on one train with float current> 1 amp.

New Units 1 and 2, TS 3.8.6, Required Actions D.1 and D.2, would state:

D.1 Perform SR 3.8.4.2.

D.2 Restore vital battery float current to ::. 1 amp.

New CTs for Units 1 and 2, TS 3.8.6, Required Actions D.1 and D.2, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months " and "12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ," respectively.

Evaluation of Units 1 and 2, TS 3.8.6, New Condition D (Added), Change (9)

The proposed new Condition D would address one or more DG battery(ies) on one train with float current greater than 1 amp. The battery float current greater than 1 amp indicates that a partial discharge of the battery has occurred. The discharge in battery may be due to a temporary loss of a battery charger or possibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity.

The proposed new Required Action D.1 would verify within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months that the DG battery terminal voltage is greater than or equal to the minimum established float voltage (revised SR 3.8.4.2),

thus confirming battery charger operability. If the DG battery terminal voltage is satisfactory, the proposed new Required Action B.2 would ensure that the affected vital battery float current is restored to less than 2 amps within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . This would confirm that the affected DG battery

had been fully recharged from any discharge that might have occurred. In its letter dated June 7, 2019, the licensee stated that the DG batteries would be fully recharged in less than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to less than 1 amp, considering the capacity of the battery chargers (rated for 20 amps) and the relatively small amount of capacity (20.82 amp-hours) that would be removed from the batteries (rated for 192 amp-hours) within the 2-hour allowed time to place a battery charger on the battery. Restoring the affected DG battery to its fully charged state provides the assurance that the battery has sufficient capacity to perform its safety function.

If the DG battery terminal voltage is found to be less than the minimum established float voltage, it indicates that the DG battery charger is either inoperable or is operating in the current limit mode. If the DG battery charger is operating in the current limit mode for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , it indicates that the DG battery has been substantially discharged and likely cannot perform its required design functions. In this case, the proposed new TS 3.8.6 Condition I would be entered.

The NRC staff concludes that, based on the above discussion, the proposed TS 3.8.6 new Condition D with its associated required actions and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.10 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition E (Added), Change ( 10)

New Units 1 and 2, TS 3.8.6, Condition E, with note, would state:

N()TE-----------------------------------------

Required Action E.2 shall be completed if electrolyte level was below the top of plates.

E. ()ne or two required vital battery(ies) on one subsystem with one or more cells electrolyte level less than minimum established design limits.

()R

()ne or two DG battery(ies) on one train with one or more cells electrolyte level less than minimum established design limits.

New Units 1 and 2, TS 3.8.6, Required Actions E.1, E.2, and E.3, with note, would state:

N()TE----------------------------------------------

Required Actions E.1 and E.2 are only applicable if electrolyte level was below the top of plates.

E.1 Restore electrolyte level to above the top of plates.

E.2 Verify no evidence of leakage.

E.3 Restore electrolyte level to greater than or equal to minimum established design limits.

New CTs for Units 1 and 2, TS 3.8.6, Required Action E.1, E.2, and E.3, would state "8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ," "12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ," and "31 days," respectively:

Evaluation of Units 1 and 2, TS 3.8.6, New Condition E (Added), Change (10)

The new Condition E would address the required vital battery(ies) on one subsystem or the DG battery(ies) on one train with cell(s) electrolyte level less than the minimum established design limits.

If the electrolyte level is above the top of the plates but below the minimum limit (i.e., minimum level indication mark on the battery cell jar), the battery should still have sufficient capacity to perform its intended safety function and is not considered inoperable. The new Required Action E.3 would restore the affected battery electrolyte level to greater than or equal to the minimum established design limits within 31 days.

With the battery cell electrolyte level below the top of the plates, there is a potential for dryout and plate degradation. The proposed new Required Action E.1 would ensure that the cell electrolyte level is restored to above the top of the plates (current Table 3.8.6-1 Category C limit for electrolyte level) within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , and the proposed new Required Action E.2 would ensure that the cause of the loss of electrolyte level is not due to a leak in the battery cell jar within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . These actions would be modified by a note to indicate that they would be applicable only if the electrolyte level is below the top of the plates. Additionally, provisions in the proposed new Battery Monitoring and Maintenance Program specified in TS 5. 7 would provide actions to equalize and test the battery cells that that have been discovered with an electrolyte level below the top of the plates. The new Required Action E.3 would restore the affected battery electrolyte level to greater than or equal to the minimum established design limits within 31 days. The NRC staff finds that the proposed new Required Actions E.1, E.2, and E.3 with associated CTs will ensure that the batteries will be restored to an operable condition in a timely manner and are, therefore, acceptable.

In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include the minimum established design limit for battery cells electrolyte level. Future changes to this value would be subject to the requirements of 10 CFR 50.59. This provides reasonable assurance that the value of the limit will be appropriately maintained by the licensee to accurately reflect the design of the batteries.

Based on the above discussion, the NRC staff concludes that the proposed TS 3.8.6 new Condition E with its associated notes, required actions, and CTs provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.11 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition F (Added), Change (11)

New Units 1 and 2, TS 3.8.6, Condition F, would state:

F. One or two required vital battery(ies) on one subsystem with pilot cell electrolyte temperature less than minimum established design limits.

OR One or two DG battery(ies) on one train with pilot cell electrolyte temperature less than minimum established design limits.

New Units 1 and 2, TS 3.8.6, Required Action F.1, would state:

F.1 Restore battery pilot cell temperature to greater than or equal to minimum established design limits.

New CT for new Units 1 and 2, TS 3.8.6, Required Action F.1, would state "12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ."

Evaluation of Units 1 and 2, TS 3.8.6, New Condition F (Added}, Change (11}

The proposed new Condition F would apply to one or two required vital battery(ies) on one subsystem or to one or two DG battery(ies) on one train found with a pilot cell electrolyte temperature less than the minimum established design limits.

Batteries are designed with margins to account for factors that affect battery performance. As described in Section 8.3 of the Watts Bar UFSAR, the vital and DG battery capacity design requirements consider the effects of aging and ambient temperature. In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include ( 1) how the vital and DG batteries are sized with correction margins that include temperature and aging and how these margins are maintained, and (2) how a 2 percent design margin for the vital and DG batteries corresponds to 2-amp float current for the vital batteries and 1-amp float current for the DG batteries, indicating that the batteries are 98 percent charged. Future changes to these values would be subject to the requirements of 10 CFR 50.59. This provides reasonable assurance that the values of the margins will be appropriately maintained by the licensee to accurately reflect the design of the batteries.

Furthermore, in its letter dated June 7, 2019, the licensee discussed the monitoring of the vital and DG battery room temperatures and actions to maintain and restore battery room temperatures within design limits. The licensee stated that the vital battery and the DG battery rooms are monitored once per shift ( 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ) by operations personnel. For the vital battery rooms, the auxiliary building heating, ventilation, and air conditioning maintains the battery room temperature within the environmental design limits. The auxiliary building heating, ventilation, and air conditioning operating procedures include compensatory actions for coping with and recovery from loss of train cooling so that design temperatures for the area are not exceeded.

For the DG batteries, the DG building ventilation system maintains temperatures within the limits of the environmental design criteria. Should the DG battery room temperatures approach temperature limits, operators will respond with plant procedures to improve room temperatures.

Based on these above considerations (i.e., battery temperature margins and room temperature monitoring) and the fact that batteries have very large thermal inertia, the NRC staff finds that a battery room temperature excursion will likely be corrected by the licensee prior to the battery electrolyte reaching its maximum or minimum design temperature. Thus, the NRC staff concludes that the pilot cell temperature is an accurate representation of the temperature of the batteries because: (1) batteries have very large thermal inertia; (2) batteries are designed with margins (i.e., temperature, aging, and design); and (3) the licensee monitors and corrects low battery room temperatures.

If pilot cell electrolyte temperature for battery(ies) on one vital DC subsystem or one DG DC train falls below the minimum established design temperature, the proposed new Required Action F .1 would restore the vital or DG battery pilot cell temperature to greater than or equal to the minimum established design limits within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . Since the temperature of the entire battery is represented by the pilot cell temperature, the 12-hour CT provides adequate time to restore the battery electrolyte temperature within established limits. Therefore, the NRC staff finds that the Required Action F.1 and associated 12-hour CT are acceptable.

In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to include the minimum established design limit for battery electrolyte temperature into the Watts Bar UFSAR. This provides reasonable assurance that the numerical value will be appropriately maintained by the licensee to accurately reflect the design of the battery subsystems.

Based on the above discussion, the NRC staff concludes that the proposed TS 3.8.6 new Condition F with its associated required action and CT provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.12 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition G, Change (12)

New Units 1 and 2, TS 3.8.6, Condition G, would state:

G. One or more vital batteries in redundant subsystems with battery parameters not within limits.

New Units 1 and 2, TS 3.8.6, Required Action G.1, would state:

G.1 Restore battery parameters for vital batteries in one subsystem to within limits.

New CT for Units 1 and 2, TS 3.8.6, Required Action G.1, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ."

Evaluation of Units 1 and 2, TS 3.8.6, New Condition G (Added), Change (12)

The proposed new Condition G would address the condition where one or more vital batteries in redundant subsystems is (are) found with battery parameters not within limits. If this condition exists, there is not sufficient assurance that the vital batteries can perform their intended safety functions. With redundant batteries involved, loss of safety function is possible for multiple systems that depend upon the batteries.

The proposed new Required Action G.1 would restore the parameters for the affected battery in one subsystem within limits within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . Considering the potential for loss of function of components (i.e., engineered safety features, vital inverter(s)) that depend on the redundant vital batteries, the NRC staff finds the relatively short duration of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to resolve the condition reasonable and, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed TS 3.8.6 new Condition G with its associated required action and CT provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.13 Watts Bar, Units 1 and 2, TS 3.8.6, New Condition H, Change ( 13)

New Units 1 and 2, TS 3.8.6, Condition H, would state:

H. One or more DG batteries in redundant trains with battery parameters not within limits.

New Units 1 and 2, TS 3.8.6, Required Action H.1, would state:

H.1 Restore battery parameters for DG batteries in one train to within limits.

New CT for Units 1 and 2, TS 3.8.6, Required Action H.1, would state "2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ."

Evaluation of Units 1 and 2, TS 3.8.6, New Condition H (Added), Change (13)

The proposed new Condition H would address the condition where one or more DG batteries in redundant trains are found with battery parameters not within limits. If this condition exists, there is not sufficient assurance that the DG batteries can perform their intended safety functions. With redundant batteries involved, loss of function is possible for the DGs that depend upon the batteries.

The proposed new Required Action H.1 would restore the parameters for the affected DG battery in one train within limits in 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . Considering the potential for loss of function of redundant DGs that depend on the redundant DG batteries, the NRC staff finds the relatively short duration of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to resolve the condition reasonable and, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed TS 3.8.6 new Condition H with its associated required action and CT provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.14 Watts Bar, Units 1 and 2, TS 3.8.6, Current Condition B (Revised and Renumbered as Condition I), Change (14)

Current Units 1 and 2, TS 3.8.6, Condition B, states:

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

One or more batteries with average electrolyte temperature of the representative cells< 60°F for vital batteries and< 50°F for DG batteries.

OR One or more batteries with one or more battery cell parameters not within Category C values.

Revised and renumbered Units 1 and 2, TS 3.8.6, Condition I, would state:

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

OR One or two required vital battery(ies) on one subsystem with one or more battery cells float voltage < 2.07 V and float current > 2 amps.

OR One or two DG battery(ies) on one train with one or more battery cells float voltage < 2.07 V and float current > 1 amp.

Current Units 1 and 2, TS 3.8.6, Required Action B.1, states:

B.1 Declare associated battery inoperable.

Revised and renumbered Units 1 and 2, TS 3.8.6, Required Action 1.1, would state:

1.1 Declare associated battery inoperable.

The CT for the revised and renumbered Units 1 and 2, TS 3.8.6, Required Action 1.1, would remain unchanged and would state "Immediately."

Evaluation of Units 1 and 2, TS 3.8.6, Current Condition B (Revised and Renumbered as Condition I), Change (14)

Current Condition B describes conditions of battery inoperability. Current Condition B would be revised by deleting its second entry and third entry conditions, modifying its first entry condition, and adding two new alternate conditions. The second entry condition (i.e., one or more batteries with average electrolyte temperature of the representative cells< 60 °F for vital batteries and< 50 °F for DG batteries) would be deleted. The licensee proposed to monitor pilot cell electrolyte temperature (proposed new SR 3.8.6.5) instead of the average electrolyte temperature of representative cells ( current SR 3.8.6.3). The out-of-limit condition for pilot cell electrolyte temperature will be covered in the proposed new TS 3.8.6, Condition F. The third entry condition (i.e., one or more batteries with one or more battery cell parameters not within Category C values) would also be deleted. Deleting the third entry condition is consistent with the elimination of TS Table. 3.8.6-1, which includes the Category C values from TS 3.8.6. The NRC staff finds that the deletion of the second entry and third entry conditions of current Condition B is consistent with the proposed changes to the TSs and, therefore, acceptable.

The revised Condition B would be renumbered as Condition I. Current Required Action B.1 would be renumbered as Required Action 1.1 with the same CT of "immediately." The NRC staff finds that the renumbering of Condition B and Required Action B.1 as Condition I and Required Action 1.1, respectively, is editorial in nature, and is, therefore, acceptable.

The revised and renumbered Condition I would apply when battery parameters fall outside the allowance of the required actions for Condition A, B, C, D, E, F, G, or H. Under this condition, it is assumed that there is insufficient capacity to supply the maximum expected load requirements. The revised and renumbered Condition I would also address two new alternate conditions: ( 1) one or two required vital battery(ies) on one subsystem found with one or more battery cells having a float voltage less than 2.07 V and a float current greater than 2 amps, or (2) one or two DG battery(ies) on one train found with one or more battery cells having a float voltage less than 2.07 Vanda float current greater than 1 amp. In these cases, the affected

required vital battery(ies) or DG battery(ies) may not have sufficient capacity to perform their intended design functions.

The renumbered Required Action 1.1 for either of the above entry conditions for the renumbered Condition I would declare the associated battery inoperable with a CT of "immediately." Since the battery capacity may be insufficient to supply the required loads in the above conditions specified for the revised and renumbered Condition I, the NRC staff finds that the Required Action 1.1 and associated CT for the revised and renumbered Condition I are reasonable and consistent with TSTF-500, Revision 2, and are, therefore, acceptable.

Based on the above, the NRC staff concludes that the proposed TS 3.8.6 revised and renumbered Condition I with its associated required action and CT provides acceptable remedial actions that provide reasonable assurance of public health and safety.

3.2.3.15 Watts Bar, Units 1 and 2, TS 3.8.6, Current SRs 3.8.6.1, 3.8.6.2, and 3.8.6.3 (Deleted),

Change (15)

Current Units 1 and 2, TS 3.8.6, SRs 3.8.6.1, 3.8.6.2, and 3.8.6.3, state:

SR 3.8.6.1 Verify battery cell parameters meet Table 3.8.6-1 Category A limits.

SR 3.8.6.2 Verify battery cell parameters meet Table 3.8.6-1 Category B limits.

SR 3.8.6.3 Verify average electrolyte temperature of representative cells is

~ 60°F for vital batteries and ~ 50°F for the DG batteries.

The current Units 1 and 2, TS 3.8.6, SRs 3.8.6.1, 3.8.6.2, and 3.8.6.3, and their associated surveillance frequencies, would be deleted.

Evaluation of Units 1 and 2, TS 3.8.6, Current SRs 3.8.6.1, 3.8.6.2, and 3.8.6.3 (Deleted),

Change (15)

The TS Table 3.8.6-1 Category A and B limits, as referenced in current SRs 3.8.6.1 and 3.8.6.2, do not represent conditions in which the batteries cannot perform their safety functions. As discussed in Section 3.2.3.2 of this SE, the Table 3.8.6-1 Category A and B limits will be relocated to the Battery Monitoring and Maintenance Program in TS 5. 7. Since the Table 3.8.6-1 Category A and B limits referenced in the current SRs 3.8.6.1 and 3.8.6.2 will be eliminated from TS 3.8.6, the NRC staff finds that the elimination of current SRs 3.8.6.1 and 3.8.6.2 is acceptable.

The current SR 3.8.6.3 requires the monitoring of the battery's average cell electrolyte temperature. The licensee proposed to replace the monitoring of the battery average cells electrolyte temperature with the monitoring of the pilot cell electrolyte temperature in the proposed new SR 3.8.6.5 (see Section 3.2.3.20 of this SE for the NRC staff's evaluation of the proposed new SR 3.8.6.5). Because the battery cell temperature will be monitored in the proposed new SR 3.8.6.5, the NRC staff finds the elimination of the current SR 3.8.6.3 acceptable.

Based on the above, the NRC staff concludes that the proposed deletion of SRs 3.8.6.1, 3.8.6.2, and 3.8.6.3 is acceptable because the change is consistent with the proposed changes to TS 3.8.6.

3.2.3.16 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.1 (Added), Change ( 16)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.1, would state:

SR 3.8.6.1 -------------------------------------N()TE------------------------------------

Not required to be met when vital battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.1.

Verify each vital battery float current is s; 2 amps.

The frequency for the new Units 1 and 2, TS 3.8.6, SR 3.8.6.1, would state "7 days."

Evaluation of Units 1 and 2, TS 3.8.6, New SR 3.8.6.1 (Added), Change (16)

The proposed new SR 3.8.6.1 would require verification that the float current for each vital battery is less than or equal to 2 amps every 7 days.

The purpose of this SR is to determine the state of charge of the battery. Float charge is the condition in which the battery charger is supplying the continuous small amount of current (i.e.,

less than or equal to 2 amps) required to overcome the internal losses of a battery to maintain the battery in a fully charged state. The float current requirements are based on the float current indicative of a charged battery. As discussed in Section 3.2.3.3 of this SE, the use of float current to determine the state of charge of the battery is consistent with the recommendations of the battery manufacturer.

The proposed new SR 3.8.6.1 would be modified by a note that would allow SR 3.8.6.1 not to be met when the vital battery terminal voltage is less than the minimum established float voltage of the revised SR 3.8.4.1. When this minimum established float voltage is not maintained at the vital battery's terminals, it likely indicates issues with the vital battery and/or the associated battery charger. In this case, the required actions for the new TS 3.8.4 Conditions A and/or the revised TS 3.8.4 Condition B will provide the necessary and appropriate verifications of the vital battery condition. Furthermore, the float current limit is established based on the nominal float voltage value and is not directly applicable when this minimum established float voltage is not maintained.

Based on the above, the NRC staff concludes that the proposed new SR 3.8.6.1 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met and it is, therefore, acceptable.

3.2.3.17 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.2 (Added), Change ( 17)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.2, would state:

SR 3. 8. 6. 2 -------------------------------------NOTE------------------------------------

Not required to be met when DG battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.2.

Verify each DG battery float current is s 1 amp.

The frequency for the new Units 1 and 2, TS 3.8.6, SR 3.8.6.2, would state "7 days."

Evaluation of Units 1 and 2, TS 3.8.6, New SR 3.8.6.2 (Added), Change (17)

The proposed new SR 3.8.6.2 would require verification of the float current for each DG battery to be less than or equal to 1 amp every 7 days.

The purpose of this SR is to determine the state of charge of the battery. Float charge is the condition in which the battery charger is supplying the continuous small amount of current (i.e.,

less than or equal to 1 amp) required to overcome the internal losses of a battery to maintain the battery in a fully charged state. The float current requirements are based on the float current indicative of a charged battery. As discussed in Section 3.2.3.3 of this SE, the use of float current to determine the state of charge of the battery is consistent with the recommendations of the battery manufacturer.

The proposed new SR 3.8.6.2 would be modified by a note that would allow SR 3.8.6.2 not to be met when the DG battery terminal voltage is less than the minimum established float voltage of the revised SR 3.8.4.2. When this minimum established float voltage is not maintained at the DG battery's terminals, it likely indicates issues with the DG battery and/or the associated battery charger. In this case, the required actions for the new TS 3.8.4 Condition D and/or the revised TS 3.8.4 Condition E will provide the necessary and appropriate verifications of the DG battery condition. Furthermore, the float current limit is established based on the nominal float voltage value and is not directly applicable when this minimum established float voltage is not maintained.

Based on the above, the NRC staff concludes that the proposed new SR 3.8.6.2 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met and it is, therefore, acceptable.

3.2.3.18 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.3 (Added), Change ( 18)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.3, would state:

. SR 3.8.6.3 Verify each required vital battery and each DG battery pilot cell float voltage is~ 2.07 V.

The frequency for new Units 1 and 2, TS 3.8.6, SR 3.8.6.3, would state "31 days."

Evaluation of Units 1 and 2, TS 3.8.6, New SR 3.8.6.3 (Added), Change (18)

The proposed new SR 3.8.6.3 would require verifying each battery pilot cell float voltage every 31 days. The proposed 31-day frequency is consistent with the recommendations of IEEE Std. 450-2002.

The battery cell float voltage limit of 2.07 V reflects the operability limit for the batteries. Due to the use of the 2.07 V as the minimum voltage limit for battery cells, battery pilot cells must be selected to represent the lowest voltage cells in the battery. This ensures that the other cells are above the pilot cell voltage, which must be greater than or equal to the TS limit. The licensee proposed to select the battery pilot cell based on the lowest voltage cell in the battery in accordance with the proposed new Battery Monitoring and Maintenance Program in TS 5. 7 (see Section 3.2.4.1 of this SE for the NRC staff's evaluation of the proposed new program).

The NRC staff finds that the Watts Bar method of selection of pilot cells based on the lowest voltage cell in the battery is acceptable.

Optimal long-term battery performance is obtained by maintaining a float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer. This provides adequate over-potential, which limits the formation of lead sulfate and self-discharge that could eventually render the battery inoperable. In Enclosure 2 of its September 4, 2019, letter, the licensee stated that optimal long-term battery performance is obtained by maintaining a float voltage between 2.20 to 2.25 vpc. Float voltages in this range (i.e., 2.20 to 2.25 vpc) or less, but greater than 2.07 vpc, would be addressed in the proposed new Battery Monitoring and Maintenance Program in TS 5. 7. The program would include ( 1) actions to restore battery cells with float voltage less than 2.13 V, and (2) actions to verify that the remaining cells are greater than or equal to 2.13 V when a cell or cells have been found to be less than 2.13 V. The program would also require the selection of a battery pilot cell based on the lowest voltage cell in the battery. This will ensure that when the pilot cell float voltage is greater than or equal to 2.07 V, all battery cells will be above 2.07 V. With all battery cell float voltages above 2.07 V, there is adequate assurance that the battery terminal voltage is at an acceptable threshold for establishing battery operability. Furthermore, in Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include how long-term battery performance is obtained by maintaining a float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer. Future changes to this value would be subject to the requirements of 10 CFR 50.59. This provides reasonable assurance that the numerical value of the battery's minimum float voltage will be appropriately maintained by the licensee to accurately reflect the design of the batteries.

Based on the above, the NRC staff concludes that the proposed new SR 3.8.6.3 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the associated LCOs will be met, and is, therefore, acceptable.

3.2.3.19 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.4 (Added), Change ( 19)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.4, would state:

SR 3.8.6.4 Verify each required vital battery and each DG battery connected cell electrolyte level is greater than or equal to minimum established design limits.

The frequency for new Units 1 and 2, TS 3.8.6, SR 3.8.6.4, would state "31 days."

Evaluation of Units 1 and 2, TS 3.8.6, Revised New SR 3.8.6.4 (Added), Change (19)

The proposed new SR 3.8.6.4 would require verifying each required vital battery and each DG battery connected cell electrolyte level every 31 days. The proposed 31-day frequency is consistent with the recommendations of IEEE Std. 450-2002.

Operation of the batteries at electrolyte levels greater than the minimum established design limit ensures that the battery plates do not suffer physical damage and continue to maintain adequate electron transfer capability. In Enclosure 4 of its November 29, 2018, letter, the licensee committed to relocate the monitoring of the battery electrolyte level to the Battery Monitoring and Maintenance Program in TS 5.7. This relocation will allow flexibility to monitor and control this limit at values directly related to the battery ability to perform its required safety function. The licensee also committed to incorporate the minimum established design limit for battery electrolyte level into the Watts Bar UFSAR. This provides reasonable assurance that the numerical value will be appropriately maintained by the licensee to accurately reflect the design of the batteries.

Based on the above discussion, the NRC staff concludes that the proposed new SR 3.8.6.4 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met and is, therefore, acceptable.

3.2.3.20 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.5 (Added), Change (20)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.5, would state:

SR 3.8.6.5 Verify each required vital battery and each DG battery pilot cell temperature is greater than or equal to minimum established design limits.

The frequency for new Units 1 and 2, TS 3.8.6, SR 3.8.6.5, would state "31 days."

Evaluation of Units 1 and 2, TS 3.8.6, New SR 3.8.6.5 (Added), Change (20)

The proposed new SR 3.8.6.5 would require verifying each required vital battery and each DG battery pilot cell temperature (versus average cell temperature) is greater than or equal to the minimum established design limits every 31 days. The proposed 31-day frequency is consistent with the recommendations of IEEE Std. 450-2002.

Currently, the licensee monitors battery average cell electrolyte temperature (current SR 3.8.6.3) instead of battery pilot cell temperature (proposed new SR 3.8.6.5). In order to use the battery pilot cell temperature instead of the battery average cell temperature, temperature must be used as a criterion when selecting a pilot cell. However, if it can be shown that the maximum temperature deviation across the battery does not exceed the maximum of 5 °Fas recommended by IEEE Std. 450-2002, then temperature is not a critical parameter and does not have to be considered when selecting pilot cells. The NRC staff requested the licensee to discuss the selection of the battery pilot cell based on temperature.

In its June 7, 2019, response letter, the licensee stated that ( 1) current weekly surveillance instructions identify the selection of pilot cell based on voltage and specific gravity parameters because cell temperatures are typically maintained within +/-3 °F, and (2) past actual battery surveillance data for all vital and DG batteries show that all recorded vital battery electrolyte temperatures were within the IEEE St. 450-2002 recommended maximum of 5 °F. The licensee concluded that the vital and DG battery pilot cells will not be selected based on temperature because the maximum temperature deviation across the vital and DG batteries, as recorded in the surveillance data, does not exceed the IEEE Std. 450-2002 recommended maximum of 5 °F. The NRC staff finds that, since the maximum temperature variations across the vital and DG batteries do not exceed 5 °F, temperature is not a critical parameter and does not have to be considered when selecting pilot cells for selection of battery pilot cells.

As discussed in Section 3.2.3.11 of this SE, batteries have very large thermal inertia, batteries are designed with margins to account for factors affecting performance (i.e., temperature, aging), and there is monitoring to maintain optimum battery room temperatures. As a result, the pilot cell temperature is an accurate representation of the temperature of the battery and is adequate to ensure that the minimum electrolyte temperature is maintained. In addition, depending on the available excess capacity of the associated battery, the minimum temperature necessary to support operability of the battery can vary. In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to relocate the monitoring of the battery cell temperature to the proposed new Battery Monitoring and Maintenance Program in TS 5.7. This relocation will allow flexibility to monitor and control this limit at values directly related to the battery ability to perform its intended function.

Based on the above discussion, the NRC staff concludes that the proposed new SR 3.8.6.5 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the associated LCOs will be met and is, therefore, acceptable.

3.2.3.21 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.6 (Added), Change (21)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.6, would state:

SR 3.8.6.6 Verify each required vital battery and each DG battery connected cell float voltage is.::: 2.07 V.

The frequency for new Units 1 and 2, TS 3.8.6, SR 3.8.6.5, would state "92 days."

Evaluation of Units 1 and 2, TS 3.8.6, New SR 3.8.6.6 (Added), Change (21)

The proposed new SR 3.8.6.6 would require verifying each required vital battery and each DG battery connected cell float voltage every 92 days. The proposed 92-day frequency is consistent with TSTF-500, Revision 2.

Optimal long-term battery performance is obtained by maintaining a float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer. This provides adequate over-potential, which limits the formation of lead sulfate and self-discharge, which could eventually render the battery inoperable. In Enclosure 2 of its September 4, 2019, letter, the licensee stated that optimal long-term battery performance is obtained by maintaining a float voltage between 2.20 to 2.25 vpc. Float voltages in this range (i.e., 2.20 to 2.25 vpc) or less, but greater than 2.07 vpc, would be addressed in the proposed new Battery Monitoring

and Maintenance Program in TS 5.7. The program would include (1) actions to restore battery cells with float voltage less than 2.13 V, and (2) actions to verify that the remaining cells are greater than or equal to 2.13 V when a cell or cells have been found to be less than 2.13 V. The 2.07 V individual cell limit reflects the operability limit for the batteries. With all battery cells' float voltages above 2.07 V, there is adequate assurance that the battery's terminal voltage is at an acceptable threshold for establishing battery operability. Furthermore, in Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to revise the Watts Bar UFSAR to include how long-term battery performance is obtained by maintaining a float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer.

Future changes to this value would be subject to the requirements of 10 CFR 50.59. This provides reasonable assurance that the numerical value of the battery's minimum float voltage will be appropriately maintained by the licensee to accurately reflect the design of the batteries.

Based on the above discussion, the NRC staff concludes that the proposed new SR 3.8.6.6 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the associated LCOs will be met and is, therefore, acceptable.

3.2.3.22 Watts Bar, Units 1 and 2, TS 3.8.6, New SR 3.8.6.7 (Relocated- Current SR 3.8.4.14), Change (22)

New Units 1 and 2, TS 3.8.6, SR 3.8.6.7, would state:

SR 3. 8. 6. 7 --------------------------------------NOTE-----------------------------------------

Th is Surveillance is not performed in MODE 1, 2, 3, or 4 for required vital batteries. Credit may be taken for unplanned events that satisfy this SR.

Verify battery capacity is ~ 80% of the manufacturer's rating when subjected to a performance discharge test or a modified performance discharge test.

Frequencies for Units 1 and 2, TS 3.8.6, SR 3.8.6.7, would state:

Frequency 60 months 12 months when battery shows degradation or has reached 85%

of expected life with capacity < 100% of manufacturer's rating 24 months when battery has reached 85% of the expected life with capacity ~ 100% of manufacturer's rating

Evaluation of Units 1 and 2, TS 3.8.6, New SR 3.8.6. 7 (Relocated - Current SR 3.8.4.14 ),

Change (22)

The current SR 3.8.4.14 is a battery capacity test with three surveillance frequencies, which depend on the battery's expected life, degradation, and capacity. These frequencies are based on the qualified life (typically 20 years) and known historical performance characteristics for vented lead-acid batteries as discussed in the IEEE Std. 450-2002. The proposed new SR 3.8.6. 7 would verify battery capacity similar to the current SR 3.8.4.8. The surveillance frequencies for the new SR 3.8.6. 7 would remain the same as for the current SR 3.8.4.14 and would provide adequate data points for trending to determine the state of health of the safety-related batteries given the expected service life. The surveillance frequencies (1) are appropriate given the condition of the battery, (2) allow sufficient time for corrective actions to be taken, and (3) are consistent with the safety significance of safety-related batteries. The NRC staff finds that the proposed new SR 3.8.6.7 is consistent with current SR 3.8.4.14 and is, therefore, acceptable.

Based on the above discussion, the NRC staff concludes that the proposed new SR 3.8.6. 7 meets the 10 CFR 50.36(c)(3) requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the associated LCOs will be met and is, therefore, acceptable.

3.2.4 TS 5.7 (Procedures, Programs, and Manuals) Change The proposed change to TS 5. 7 is similar for Units 1 and 2. Therefore, the below NRC staff evaluation of the proposed change to TS 5. 7 is applicable to both units.

3.2.4.1 Watts Bar, Units 1 and 2, TS 5.7.2.22, New Battery Monitoring and Maintenance Program (Added), Change (1)

New Units 1 and 2, TS 5. 7 .2.22, would state:

TS 5.7.2.22 Battery Monitoring and Maintenance Program This Program provides controls for battery restoration and maintenance. The program shall be in accordance with IEEE Standard (Std.) 450-2002, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," as endorsed by Regulatory Guide 1.129, Revision 2 (RG), with RG exceptions and program provisions as identified below:

a. The program allows the following RG 1.129, Revision 2 exceptions:

1. Battery temperature correction may be performed before or after conducting discharge tests.

2. RG 1.129, Regulatory Position 1, Subsection 2, "References," is not applicable to this program.

3. In lieu of RG 1.129, Regulatory Position 2, Subsection 5.2, "Inspections," the following shall be used: "Where reference is made to the pilot cell, pilot cell selection shall be based on the lowest voltage cell in the battery."

4. In Regulatory Guide 1.129, Regulatory Position 3, Subsection 5.4.1, "State of Charge Indicator," the following statements in paragraph (d) may be omitted: "When it has been recorded that the charging current has stabilized at the charging voltage for three consecutive hourly measurements, the battery is near full charge.

These measurements shall be made after the initially high charging current decreases sharply and the battery voltage rises to approach the charger output voltage."

5. In lieu of RG 1.129, Regulatory Position 7, Subsection 7 .6, "Restoration", the following may be used: "Following the test, record the float voltage of each cell of the string."

b. The program shall include the following provisions:

1. Actions to restore battery cells with float voltage

< 2.13 V;

2. Actions to determine whether the float voltage of the remaining battery cells is ~ 2.13 V when the float voltage of a battery cell has been found to be

< 2.13 V;

3. Actions to equalize and test battery cells that had been discovered with electrolyte level below the top of the plates;

4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and

5. A requirement to obtain specific gravity readings of all cells at each discharge test, consistent with manufacturer recommendations.

Evaluation of Units 1 and 2. TS 5.7.2.22. Battery Monitoring and Maintenance Program.

Change (1)

The proposed new Battery Maintenance and Monitoring Program would be in accordance with IEEE Std. 450-2002, as endorsed by RG 1.129, Revision 2. RG 1.129, Revision 2, provides guidance with respect to the maintenance, testing, and replacement of vented lead-acid storage

batteries in nuclear power plants. The exceptions to RG 1.129, Revision 2 (listed in TS 5.7.2.22), represent reasonable technical approaches and are appropriate for applying the RG provisions to the proposed TS requirements for operating plants.

In Enclosure 4 of its November 29, 2018, letter, the licensee provided a commitment to relocate the monitoring of the current battery parameters (i.e., specific gravity, electrolyte level, cell temperature, float voltage, connection resistance, and physical condition) to the proposed new Battery Monitoring and Maintenance Program. The program will ensure that the above battery parameters will be maintained and that actions will be implemented should the battery parameter(s) not be met.

TS 5.7.1, "Procedures," requires written procedures to be established, implemented, and maintained for the proposed new Battery Monitoring and Maintenance Program in TS 5.7.2.22.

The program provides assurance that the battery parameters will be monitored and controlled in accordance with the program, and that actions to restore deficient parameters will be implemented in accordance with the licensee's corrective action program. Furthermore, the batteries and their preventive maintenance and monitoring program continue to be subject to the regulatory requirements of 10 CFR 50.65.

The NRC staff finds that the proposed new Battery Monitoring and Maintenance Program is consistent with TSTF-500, Revision 2, and provides assurance that the battery will be maintained at required levels of performance and that pertinent battery parameters will be monitored. Based on the above discussion, the NRC staff concludes that the proposed new TS 5.7.2.22, Battery Monitoring and Maintenance Program, provides the necessary provisions relating to procedures to assure safe operation of the facility.

3.3 Regulatory Commitments In Enclosure 4 of its letters dated November 29, 2018; June 7, 2019; and September 4, 2019, the licensee provided the following regulatory commitments to be implemented with the amendments:

Commitment Due Date/Event TVA commits to include in the UFSAR a requirement to Prior to implementation of maintain a 2 percent design margin for the vital batteries the approved TSTF-500 which corresponds to a 2 amp float current value being used license amendment as an indication that the battery is at least 98 percent charged.

TVA commits to include in the FSAR [Final Safety Analysis Prior to implementation of Report] a requirement to maintain a 2 percent design margin the approved TSTF-500 for the DG batteries which corresponds to a 1 amp float license amendment current value being used as an indication that the battery is at least 98 percent charged.

Commitment Due Date/Event TVA commits that the licensee-controlled program, required Prior to implementation of and described in TS Section 5.7, "Programs, Programs, and the approved TSTF-500 Manuals," and titled, "Battery Monitoring and Maintenance license amendment Program," will require verification of the selection of the pilot cell or cells when performing SR 3.8.6.6.

TVA commits to a licensee-controlled program that will require Prior to implementation of the availability of a means to charge the batteries that is the approved TSTF-500 capable of being supplied power from a power source that is license amendment independent of the offsite power supply.

TVA commits to verify that the equipment that will be used to Prior to implementation of monitor float current under SR 3.8.6.1 and SR 3.8.6.2 will the approved TSTF-500 have the necessary accuracy and capability to measure license amendment electrical currents in the expected range. Additionally, TVA commits to verify that the minimum required procedural time to measure battery float current will be 30 seconds or as recommended by the float current measurement instrument manufacturer.

TVA commits to relocating the monitoring of battery Prior to implementation of parameters (i.e., specific gravity, electrolyte level, cell the approved TSTF-500 temperature, float voltage, connection resistance, and license amendment physical condition) to the licensee-controlled program, required and described in TS Section 5.7, "Programs, Programs, and Manuals," and titled the "Battery Monitoring and Maintenance Program."

TVA commits to revising the FSAR to include the following: Prior to implementation of the approved TSTF-500

1) How a 2 percent design margin for the vital batteries license amendment corresponds to a 2 amp float current value indicating that the battery is at least 98 percent charged.

2) How a 2 percent design margin for the DG batteries corresponds to a 1 amp float current value indicating that the battery is at least 98 percent charged.

3) How long term battery performance is obtained by maintaining a float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer.

4) How the batteries are sized with correction margins that include temperature and aging and how these margins are maintained.

5) The minimum established design limit for battery terminal float voltage.

6) The minimum established design limit for electrolyte level.

7) The minimum established design limit for electrolyte temperature.

Commitment Due Date/Event

8) How each battery is designed with additional capacity above that required by the design duty cycles to allow for temperature variations and other factors.

9) Normal DC system operation i.e., powered from the battery chargers with the batteries floating on the system, and with a loss of normal power to the battery charger.

10) The minimum requirements for the alternate means (i.e., spare battery charger) that are used to obtain an extended battery charger CT.

11) TVA will revise the Watts Bar FSAR to reflect consistent terminology regarding the arrangement of the diesel generator (DG) direct current electrical power system in four subsystems, with one subsystem suooortinq each DG.

The NRC staff notes that the above descriptions in Commitment Nos. 1 - 11 will be incorporated into the Watts Bar UFSAR prior to the implementation of the approved amendments and submitted in the subsequent UFSAR update, as required by 10 CFR 50.71(e).

Thus, future changes to the descriptions in the UFSAR will be adequately controlled under the provisions of 10 CFR 50.59.

3.4 Summary and Conclusion Based on the above evaluation, the NRC staff finds that the proposed changes to the Units 1 and 2 TSs to adopt TSTF-500, Revision 2, provide assurance of the continued availability of the vital and DG DC power required to shut down the reactor and to maintain the reactor in a safe condition after an anticipated operational occurrence or a postulated design-basis accident. The NRC staff also finds that the proposed TS changes continue to meet the requirements of 10 CFR 50.36. Therefore, the NRC staff concludes that the proposed changes are acceptable.

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendments on October 9, 2019. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFRPart 20 and change SRs.

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 amendments involve no significant hazards consideration, published in the Federal Register on September 12, 2019 (84 FR 48180), 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 Commission's 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.

Principal Contributor: A. Foli Date: December 9, 2019

J. Barstow

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNITS 1 AND 2 - ISSUANCE OF AMENDMENT NOS. 130 AND 33 REGARDING ADOPTION OF TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER TSTF-500, "DC ELECTRICAL REWRITE- UPDATE TO TSTF-360" (EPID L-2018-LLA-0494)

DATED DECEMBER 9, 2019 DISTRIBUTION:

PUBLIC PM File Copy RidsACRS_MailCTR Resource RidsNrrDorlLpl2-2 Resource RidsNrrDeEeob Resource RidsNrrDssStsb Resource RidsNrrPMWattsBar Resource RidsNrrLABLRonewica Resource RidsRgn2MailCenter Resource AFoli, NRR ADAMS Access1on No.: ML19276E557 *b1y e-ma1*1 OFFICE NRR/DORULPL2-2/PM NRR/DORULPL2-2/LA NRR/DE/EEOB/BC(A)

NAME MWentzel LRonewicz DWilliams DATE 10/08/2019 10/08/2019 9/25/2019 OFFICE NRR/DSS/STSB/BC* OGC- NLO(w/edits)* NRR/DORULPL2-2/BC NAME VCusumano DRoth UShoop DATE 10/24/2019 11/12/2019 12/09/2019 OFFICE NRR/DORULPL2-2/PM NAME MWentzel DATE 12/09/2019 OFFICIAL RECORD COPY

v t e Letter Sequence Approval
EPID:L-2018-LLA-0494, TSTF-500 (Approved, Closed)
Initiation Acceptance... Supplement Administration Meeting Questions Answers 7 June 2019 Results Approval, Approval Other: ML19241A295, ML19241A296
MONTHYEAR2019-12-09 [Table View]

ML19276E557

Text

SUBJECT:

Dear Mr. Barstow:

Enclosures:

Attachment:

Attachment:

1.0 INTRODUCTION

2.0 REGULATORY EVALUATION

3.0 TECHNICAL EVALUATION

4.0 STATE CONSULTATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 CONCLUSION

SUBJECT:

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