Text

Application to Modify Watts Bar Nuclear Plant, Unit I Technical Specifications (TS) 3.8.4, 3.8.5, and 3.8.6 (WBN-TS-12-07)
	ML13248A250
Person / Time
Site:	Watts Bar
Issue date:	08/28/2013
From:	James Shea; Tennessee Valley Authority
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	WBN-TS-12-07
	Download: ML13248A250 (137)
	v • d • e

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 August 28, 2013 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1 Facility Operating License No. NPF-90 NRC Docket No. 50-390

SUBJECT:

Application to Modify Watts Bar Nuclear Plant, Unit I Technical Specifications (TS) 3.8.4, 3.8.5, and 3.8.6 (WBN-TS-12-07)

In accordance with the provisions of 10 Code of Federal Regulations (CFR) 50.90, "Application for amendment of license, construction permit, or early site permit," the Tennessee Valley Authority (TVA) is submitting a request for an amendment to Facility Operating License No. NPF-90 for Watts Bar Nuclear Plant (WBN) Unit 1.

TVA proposes this License Amendment Request (LAR) for the WBN, Unit 1 Technical Specifications (TS) to modify TS 3.8.4, "DC Sources-Operating," TS 3.8.5, "DC Sources-Shutdown," and TS 3.8.6, "Battery Cell Parameters." This amendment request includes changes consistent with both Technical Specifications Task Force (TSTF) change traveler TSTF-360, Revision 1, "DC Electrical Rewrite," and TSTF-500, "DC Electrical Rewrite -

Update to TSTF-360," which provided an update to the changes approved in TSTF-360.

However, the proposed TS changes are based on those TSTF-360 and TSTF-500 changes that are appropriate to the WBN Unit 1 design, because the direct current (DC) electrical power distribution system referenced in the model application is significantly different the system that exists at Watts Bar. Furthermore, due to these differences, TVA has not utilized the model application for TSTF-500, but has provided plant specific justifications for the related TSTF-500 changes being proposed in this LAR. In addition to the TSTF-360 and TSTF-500 related changes, editorial and clarification changes are being made to TS 3.8.4, 3.8.5, and 3.8.6. to this letter provides a description, technical evaluation, regulatory evaluation, and environmental consideration of the proposed changes. Attachments 1 and 2 to the enclosure provide the TS and TS Bases pages marked-up to show the proposed changes. Attachments 3 and 4 to the enclosure provide the existing TS and Bases pages retyped with the proposed changes incorporated.

paper onrecycled Prin~ted I c c

U.S. Nuclear Regulatory Commission Page 2 August 28, 2013 to the enclosure contains a letter from the battery manufacturer verifying the acceptability of using float current monitoring as a reliable and accurate indication of the state-of-charge of the battery, which will hold true over the life of the battery. Attachment 6 to the enclosure is a schematic diagram of the WBN 120V AC and 125V DC Vital Plant Control Power System for information only.

TVA requests approval of this TS change by August 30, 2014, and will implement revised TSs within six months of NRC approval.

TVA has determined that there are no significant hazards considerations associated with the proposed change and that the changes qualify for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9).

The WBN Plant Operations Review Committee and the WBN Nuclear Safety Review Board have reviewed the proposed changes and determined that operation of WBN, in accordance with the proposed change, will not endanger the health and safety of the public.

Additionally, in accordance with 10 CFR 50.91(b)(1), TVA is sending a copy of this letter and enclosures to the Tennessee State Department of Environment and Conservation.

Enclosure 2 provides the list of regulatory commitments associated with this License Amendment Request.

If you have any questions about this change, please contact Mr. E. D. Schrull at 423-751-3850.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th day of August 2013.

Respe u y, J. . hkea Vi e P \sident, Nuclear Licensing Enclosure cc: See Page 3

U.S. Nuclear Regulatory Commission Page 3 August 28, 2013

Enclosures:

1. Evaluation of Proposed Change

2. List of Regulatory Commitments cc (Enclosures):

NRR Project Manager - Watts Bar Nuclear Plant, Unit 1 NRC Regional Administrator - Region II NRC Resident Inspector - Watts Bar Nuclear Plant, Unit 1 NRC Resident Inspector - Watts Bar Nuclear Plant, Unit 2 Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation

ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT UNIT 1 EVALUATION OF PROPOSED CHANGE

Subject:

Application to Modify Watts Bar Nuclear Plant (WBN), Unit ITechnical Specifications (TS) 3.8.4, 3.8.5, and 3.8.6 (WBN-TS-12-07)

1.

SUMMARY

DESCRIPTION

2. DETAILED DESCRIPTION

3. TECHNICAL EVALUATION

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 No Significant Hazards Consideration Determination 4.4 Conclusions

5. ENVIRONMENTAL CONSIDERATION

6. REFERENCES ATTACHMENTS

1. Proposed WBN Unit 1 TS Changes (Markups)

2. Proposed WBN Unit 1 TS Bases Page Changes (Markup) (For Information Only)

3. Proposed WBN Unit 1 TS Changes (Final Typed)

4. Proposed WBN Unit 1 TS Bases Changes (Final Typed) (For Information Only)

5. Plant Specific Verification Regarding the Use of Float Current Monitoring to Verify Battery State of Charge

6. 120V AC & 125V DC Vital Plant Control Power System Diagram E1-1 of 29

1.0

SUMMARY

DESCRIPTION This evaluation supports a request to amend the Watts Bar Nuclear Plant (WBN), Unit 1, Facility Operating License No. NPF-90. The proposed changes will modify WBN, Unit 1 Technical Specification (TS) requirements related to direct current (DC) electrical systems in TS 3.8.4, "DC Sources - Operating," TS 3.8.5, "DC Sources - Shutdown," and TS 3.8.6, "Battery Cell Parameters." In addition, a new "Battery Monitoring and Maintenance Program" is being proposed for Technical Specification 5.7.2.21. The proposed TS changes place requirements on the battery itself rather than the battery cells as currently required.

Specifically, the proposed changes to TS 3.8.4 provide new actions for an inoperable battery charger and alternate testing criteria in the applicable Surveillance Requirements (SRs). The proposed changes also include the relocation of a number of SRs in TS 3.8.4 that perform preventive maintenance on the safety-related batteries to a licensee-controlled program. The proposed changes also modify TS 3.8.6 by relocating TS Table 3.8.6-1, "Battery Cell Parameter Requirements," to a licensee-controlled program, and adding specific actions with associated Completion Times (CTs) for out-of-limits conditions for battery cell voltage, electrolyte level, and electrolyte temperature to TS 3.8.6. Specific SRs are also being proposed for verification of these parameters.

A new program is being proposed as TS 5.7.2.21 for the maintenance and monitoring of station batteries. The items proposed to be relocated will be contained within this program, titled the "Battery Monitoring and Maintenance Program."

These changes are consistent with the Nuclear Regulatory Commission (NRC)-approved Technical Specifications Task Force (TSTF) Travelers TSTF-360, Revision 1, "DC Electrical Rewrite" (Reference 1), and TSTF-500, Revision 2, "DC Electrical Rewrite - Update to TSTF-360" (Reference 2), which provided an update to the changes approved in TSTF-360.

However, since the model application provided in the NRC-approved TSTF-500, Revision 2, referenced a DC electrical power distribution system design that is significantly different from that which exists at Watts Bar, the proposed TS changes are based on those TSTF-360 and TSTF-500 changes that are appropriate to the WBN Unit 1 design. Furthermore, due to these differences, TVA has not utilized the model application for TSTF-500, but has provided plant specific justifications for the related TSTF-500 changes being proposed in this LAR. In addition to the TSTF-360 and TSTF-500 related changes, editorial and clarification changes are being made to TSs 3.8.4, 3.8.5, and 3.8.6.

In addition to the TSTF-360 and TSTF-500 related changes, some editorial changes as well as some clarification changes to these three Technical Specifications are being proposed to improve the use and readability of TSs 3.8.4, TS 3.8.5, and TS 3.8.6.

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2.0 DETAILED DESCRIPTION

Background

Vital 125V DC Control Power System The Vital 125 volt (V) DC Control Power System is a Class 1E DC electrical power system (Reference 4) that provides control power to the emergency alternating current (AC) power system (Reference 5). The 125V DC vital control power system is composed of four redundant channels (designated as Channels 1,11, 111, and IV) which are shared by both WBN Units 1 and 2. Each channel consists of a battery charger that supplies normal DC power, a battery for emergency DC power, and a battery board to facilitate load grouping and provide circuit protection.

Loads are assigned according to their divisional requirements and are shared with WBN Units 1 and 2. Loads requiring four divisions of separation are assigned to the four channels (e.g., Reactor Protection System and Engineered Safety Feature (ESF) Actuation Systems).

Loads requiring two divisions of separation are assigned to Train 1A and 2A (load group A) and Train 1 B and 2B (load group B) and are primarily associated with the ESF systems. One load group can mitigate a design basis accident on one unit and safely shut down the other unit assuming a loss of offsite power to both units.

For load group A, the normal and alternate DC control voltage for the 6.9 kV and 480 V shutdown boards are provided by Channels I and III and for load group B, by Channels II and IV. Loads that do not require divisional separation are assigned among the four channels.

Vital Battery Boards 1,11, 111, and IV have manual access to two spare (backup) chargers for use upon loss of the normal charger. Each pair of spare chargers is mechanically interlocked such that only one charger in each pair can be utilized at a time. Additionally, Vital Battery Boards I, II, Ill, and IV have manual access to a fifth 125V DC Vital Battery System. This fifth 125 DC Vital Battery System is intended to serve as a replacement for any one of the four 125V DC vital batteries during testing, maintenance, and outages with no loss of system reliability under any mode of operation. This arrangement is shown in Attachment 6, Figure 8.1-3.

As shown in UFSAR Figure 8.1-3, the WBN Unit 1 125V DC Vital Control Power System differs substantially from the standard plant design assumed in TSTF-500 and the model NRC Safety Evaluation for the TSTF. The DC System design referenced in TSTF-500 consists of two independent and redundant DC power trains per unit. As discussed above, the WBN Unit 1 125V DC Vital Control Power Systems consists of four redundant channels that are shared with WBN Unit 2. For these reasons, and also that WBN TSs differ from NUREG-1431, Revision 3.1 (which were the basis for TSTF-500), the proposed TS changes are based on those TSTF 360 and TSTF-500 changes that are appropriate to WBN Unit 1 design.

WBN Unit 1 is licensed to 10 CFR 50, Appendix A, General Design Criteria (GDC) 17. The DC electrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a single failure.

As described in the WBN Unit 1 UFSAR Section 8.3.2 (Reference 5), during normal operation the DC load is powered from the battery chargers with the batteries floating on the system. In case of loss of normal power to the battery charger, the DC load is automatically powered from the station batteries.

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Each battery is separately housed in a ventilated room apart from its charger and distribution centers. Each subsystem is located 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 between redundant Class 1 E subsystems, such as batteries, battery chargers, or distribution panels.

Each battery has adequate storage capacity to meet the duty cycle assumptions contained in the WBN Unit 1, UFSAR Section 8.3.2 (Reference 5). Each battery is designed with additional capacity above that required by the design duty cycles to allow for temperature variations and other factors.

Each DC electrical power subsystem battery charger has ample power output capacity for the steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged. Each battery charger also has sufficient excess capacity to restore the battery from the design minimum charge to its fully charged state while supplying normal steady state loads.

Each battery charger is normally 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.

The normal supply of DC current to the vital battery -boards is from the battery charger in each channel. Each charger maintains a float voltage of approximately 135V DC on the associated battery board with the battery connected to the board and is capable of maintaining 140V DC during an equalizing charge period (all loads can tolerate the 140 volt equalizing voltage). The charger supplies normal steady state DC load demand on the battery board and maintains the battery in a charged state. Normal recharging of the battery from the design discharged condition can be accomplished in approximately 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (with accident loads being supplied) following a 30-minute AC power outage and in approximately 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (with normal loads being supplied) following a 4-hour AC power outage. The battery chargers, including the spare chargers if in service, are automatically loaded on the diesel generators following a loss of offsite power (LOOP) event. Two pairs of spare chargers are available for the four channels (two each for two channels). Each spare charger can be connected to either of its two assigned channels. It can also be substituted for or operate in parallel with the normal charger in that channel.

Alternating current power for each charger is derived from the station auxiliary power system via two 480V AC 3-phase circuits which are physically and electrically independent. Each circuit has access to a preferred (offsite) and a standby (onsite) source. If the normal circuit supplying a charger is unavailable, the alternate circuit is selected by a manual transfer. The transfer switches are mechanically interlocked to prevent closing switches in a manner to parallel both feeds. The alternate 480V feeder breakers are verified open in accordance with the TSs. Each charger is equipped with a DC voltmeter, DC ammeter, and charger abnormal alarm.

Malfunction of a charger is annunciated in the Main Control Room. Upon loss of normal power to a charger, each may be energized from the standby power system.

Chargers 1,11, 111, IV, and V are solid-state type devices that convert a 3-phase 480V AC input to a nominal 125V DC output having a rated capacity of 200 amperes. Over this output current E1-4 of 29

range, the DC output voltage will vary no more than +/- 1.0% for a supply voltage amplitude variation of +/- 7.5% and frequency variation of +/- 2.0%.

The operational features of the chargers include:

(1) float and equalize modes of operation; (2) output voltage adjustable over the range of 125 to 140 volts; (3) a current limit feature which limits continuous overload operation to 125% of rated output; (4) protective devices which prevent a failed charger from discharging its associated battery and protect the charger from external overloads; (5) metering and alarm circuits to monitor the charger output; (6) parallel operation capability; and (7) high voltage cutout function that will trip the output breaker in the event there is an over-voltage condition.

The chargers normally operate in the float mode at 135V DC for Batteries I through IV and 138.5V DC for Battery V. The maximum equalizing voltage for Batteries I through IV is 140V DC when connected to the distribution system. The system configuration, using substitution of Battery V, permits off-line equalization at higher than normal values.

Emer-gency DC Supply The emergency supply of DC current to each distribution board is from its associated vital battery. There are five vital batteries for the plant; one associated with each channel and Vital Battery V, which serves as a temporary replacement for Vital Battery 1,11, 111 or IV. These batteries are physically and electrically independent. The vital batteries supply the entire plant DC load in the event the normal power source is unavailable. With normal power unavailable, three vital batteries are capable of supplying all loads required for safe shutdown of both units continuously for 30 minutes. The batteries also have the capability to supply the essential loads required to maintain the plant in a safe shutdown condition for four hours following a loss of all normal and standby AC power, but no accident (i.e., a station blackout). 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 the standby diesel generator (DG).

Diesel Generator 125V DC Control System 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. Battery capacity design requirements consider minimum required voltage for loads and the effects of aging and ambient temperature. 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, E1-5 of 29

comprised of 58 cells, have adequate capacity considering the minimum terminal voltage of 105V DC and de-rating for 50°F temperature and aging.

The normal supply of DC current to the battery boards is from the battery charger. Each charger maintains a float voltage of approximately 130V DC on the associated battery board with the battery connected to the board and is capable of maintaining 135V DC during an equalizing charge period (all loads can tolerate approximately 135V DC equalizing voltage).

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. If the normal charger is unavailable, the alternate charger is selected by the 125V DC transfer switch included in the assembly. The charger is a solid-state type which converts a 3-phase 480V AC input to a nominal 125V DC output. The DC output voltage will vary no more than +/- 1.0% for a supply voltage amplitude variation of +/- 10% and frequency variation of +/- 2.0%. Some operational features of the chargers are:

(1) an output voltage adjustable over the range of 125 to 135 volts; (2) equalize and float modes of operation (the charger normally operates in the float mode at 130V DC, but can be switched to the equalize mode with an output of 135V DC; (3) a current-limit feature which limits continuous overload operation to approximately 140%

of rated output; (4) protective devices which prevent a failed charger from loading the battery; and (5) metering and alarm circuits to monitor the charger output.

2.1 Proposed TS Changes The proposed adoption of TSTF-500, Revision 2, provides new TS Actions for an inoperable battery charger and alternate battery charger testing criteria. A longer Completion Time (CT) for an inoperable battery charger will allow additional time for maintenance and testing.

In addition, monitoring requirements for battery cell parameters and performance requirements for battery maintenance activities are proposed to be relocated from the TSs to a licensee-controlled program. This focuses TS requirements on the analysis basis safety function of the battery.

The proposed TS changes are as following.

Revise 3.8.4, "DC Sources Operating" to add Conditions for inoperable battery chargers and inoperable batteries, and relocate SRs on battery corrosion, connection resistance, and visual inspection, to the new Battery Monitoring and Maintenance Program. Allow use of the Modified Performance testing to satisfy SRs for Service Testing and Performance Testing.

" Revise the list of TS 3.8.4 SRs in TS 3.8.5, "DC Sources - Shutdown," that must be met to be consistent with the changes to TS 3.8.4.

Rename TS LCO 3.8.6, "Battery Cell Parameters" to "Battery Parameters."

Delete TS Table 3.8.6-1.

" Relocate TS 3.8.6 Conditions and SRs for battery cell parameters that do not meet Category A and B limits to the new Battery Monitoring and Maintenance Program.

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Retain Category C limits for cell float voltage and electrolyte level in new proposed TS. Relocate specific gravity limits to the new Battery Monitoring and Maintenance Program and replaced with float current monitoring to determine battery state of charge.

Relocate SR for battery capacity test from TS 3.8.4 to TS 3.8.6.

Add TS 5.7.2.21, "Battery Monitoring and Maintenance Program."

A detailed description of the proposed Technical Specification changes are shown in to this Enclosure 2.2 Need for Proposed Changes WBN Unit 1 Technical Specifications were initially written and approved by the NRC based on the original revision of NUREG-1431, "Standard Technical Specifications - Westinghouse Plants." Since the issuance of Revision 0, many changes have been made to NUREG-1431 to enhance, improve, and clarify the Technical Specifications. One area of enhancements and improvements is in the area of DC sources, TSs 3.8.4, TS 3.8.5, and TS 3.8.6. WBN Unit 1 has not previously updated the WBN Unit 1 Technical Specification to include two of the major changes to these Specifications, TSTF-360 and TSTF-500. Therefore, WBN Unit 1 is proposing to update these three Technical Specifications to bring the WBN Unit 1 Technical Specifications more in line with the industry Standard Technical Specifications. In addition, some editorial and clarification changes related to these three Technical Specifications are also being proposed.

3.0 TECHNICAL EVALUATION

3.1 Changes to TS 3.8.4 DC Sources - Operating TVA proposes to revise TS 3.8.4 LCO Notes, Conditions, Required Actions, and SRs as described below.

3.1.1 LCO 3.8.4 Notes The proposed change revises the Notes for LCO 3.8.4 as follows.

1. Vital Battery V may be substituted for any required vital battery.

2. Spare Vital Battery Chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers.

3. Spare DG Battery Chargers 1Al, 1 B1, 2A1, or 2B1 may be substituted for required DG chargers.

4. 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.

Technical Justification for LCO 3.8.4 Note changes Existing Note 2 is renumbered Note 4. New Notes 2 and 3 allow substitution of the spare vital battery and DG battery chargers for the required battery chargers. The spare battery chargers are fully qualified and appropriately sized to perform their design safety function as those being replaced. The description of the chargers, both normal and spare (also identified as alternate) is provided in Section 2.0 (Background) of this enclosure.

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3.1.2 TS 3.8.4 Actions A and E The proposed change adds new Conditions A and E to address the conditions in which one required vital battery charger on one channel (Condition A) or one required DG battery charger on one train (Condition E) is inoperable. The proposed change increases the Completion Time (CT) for an inoperable battery charger from the existing 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in current Required Actions A. 1 and C.1 to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months in proposed Required Actions A.3 and E.3, provided that battery terminal voltage is 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 (Required Actions A.1 and E.1), and battery float current is verified to be less than or equal to 2 amps for the vital battery and 1 amp for the DG battery once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Actions A.2 and E.2).

Technical Justification for TS 3.8.4 Actions A and E changes New Actions A and E apply when one required vital battery charger on one channel (proposed Condition A) or one required DG battery charger on one train (proposed Condition E) is inoperable. The term "required" is added since there are spare chargers, as stated and discussed in proposed Notes 2 and 3 (i.e., not all installed chargers are required by the LCO to be operable). There are three associated Required Actions for new Conditions A and E. The 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.

Required Actions A. 1 and E. 1 require the 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 . Required Actions A.2 and E.2 require the vital battery float current to be verified to be < 2 amps and the DG battery float current to be verified to be < 1 amp once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . Required Actions A.3 and E.3 require the battery charger to be restored to operable status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

New Required Actions A.1 and E.1 provide assurance that a battery discharge is terminated by requiring that the battery terminal voltage 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 DC control power to AC circuit breakers and thus supports the recovery of AC power following events such as loss-of-offsite power (LOOP) or station blackout (SBO). The 2-hour CT provides an allowance for returning an inoperable charger to operable status or for reestablishing an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage. This provides assurance that the battery will be restored to its fully charged condition from any discharge that might have occurred due to the battery charger being inoperable. At the end of the 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , 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.

New Required Actions A.2 and E.2 require that once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , the battery float current be verified to be < 2 amps for the vital battery and < 1 amp for the DG battery. This confirms that if the battery has been discharged as the result of an inoperable battery charger, it had been recharged. If at the expiration of the 12-hour period, the float current for the vital battery is greater than 2 amps or greater than 1 amp for the DG battery, then the battery is considered inoperable. This verification provides assurance that the battery has sufficient capacity to perform its safety function.

New Required Actions A.3 and E.3 require restoring the inoperable battery charger to operable status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The presumptions that: (1) the DC bus remains energized; (2) the battery discharge is terminated based on restoration of the battery terminal voltage (New E1-8 of 29

Required Actions A.1 and E.1); and (3) the battery is fully recharged based upon battery float current (New Required Actions A.2 and E.2), establish a basis for extending the restoration time for an inoperable battery charger beyond the existing 2-hour CT to 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months (New Required Actions A.3 and E.3).

3.1.3 TS 3.8.4 Actions B and F The proposed change would add new Actions B and F, which would apply when one required vital battery on one channel or one required DG battery on one train is inoperable. The proposed Required Action would state that the battery must be restored to operable status within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

Technical Justification for TS 3.8.4 Actions B and F changes With batteries on one channel or train inoperable, the DC bus is being supplied by an operable battery charger(s). Any event that results in a loss of the AC bus supporting the battery charger(s) will also result in loss of DC power to that subsystem. Recovery of the AC bus, especially if it is due to a LOOP, will be hampered by the fact that many of the components necessary for the recovery (e.g., diesel generator control and field flash, AC load shed and diesel generator output circuit breakers) will rely on battery power. The 2-hour limit is sufficient time and appropriate to effect restoration of an inoperable battery, because the majority of the limiting conditions which lead to battery inoperability (e.g., loss of battery charger, inadequate battery cell voltage) are verified to be met by TSs 3.8.4, 3.8.5, and 3.8.6 along with the allowed Required Actions and associated CTs. In addition, these proposed Actions are consistent with current TS 3.8.4 Actions A and C, which currently apply to the condition of one inoperable vital battery or DG battery.

3.1.4 TS 3.8.4 Conditions A, B, C, and D Renumberinq The proposed change renumbers existing Condition A to Condition C and the exception "for reasons other than Condition A or B" is added to renumbered Condition C. Existing Condition C is renumbered to Condition G and the exception "for reasons other than Condition E or F" is added to renumbered Condition G. Existing Condition B is renumbered to Condition D and the phrase "of Condition A" is changed to "of Condition A, B, or C." Existing Condition D is renumbered to Condition H and the phrase "of Condition C is changed to "of Condition E, F, and G."

Technical Justification for TS 3.8.4 Conditions A, B, C, and D Renumbering changes The proposed change is editorial in nature and will not result in new requirements or change operational restrictions or flexibility. The Conditions are renumbered and the additional words added to the Conditions due to the addition of the proposed Actions A, B, E, and F, as described in subsections 3.1.2 and 3.1.3 above.

3.1.5 SR 3.8.4.1 and SR 3.8.4.2 SR 3.8.4.1 The proposed change revises SR 3.8.4.1 from "Verify vital battery terminal voltage is > 128V (1 32V for Vital Battery V) on float charge" to "Verify vital battery terminal voltage is greater than or equal to the minimum established float voltage." The frequency of 7 days remains E1-9 of 29

unchanged. The value for the minimum established float voltage is removed from the this TS and controlled by the new TS 5.7.2.21 (described below in section 3.4).

SR 3.8.4.2 The proposed change revises SR 3.8.4.2 from "Verify DG battery terminal voltage is > 124V on float charge" to "Verify DG battery terminal voltage is greater than or equal to the minimum established float voltage." The frequency of 7 days remains unchanged. The value for the minimum established float voltage is removed from this TS and controlled by the new TS 5.7.2.21 (described below in section 3.4).

Technical Justification for SR 3.8.4.1 and SR 3.8.4.2 changes This change removes specific terminal voltage criteria currently identified in SR 3.8.4.1 and SR 3.8.4.2 from the TS. The purpose of SR 3.8.4.1 and SR 3.8.4.2 is to verify battery terminal voltage while the system is on a float charge to ensure the effectiveness of the battery charger is not degraded. The battery terminal voltage selected by the battery manufacturer is the minimum voltage which ensures an optimum charging voltage is applied to the battery. The minimum established float voltage will maintain the battery plates in a condition that supports optimizing battery grid life. Maintaining this voltage limit ensures that the battery will be capable of providing its designed safety function. Furthermore, the change to 2.07V for SR 3.8.6.3 (described in subsection 3.3.12 below) will require battery pilot cells to be selected from those that represent the lowest voltage cells in the battery. This ensures that the other cells should be above the pilot cell voltage and above the TS limit.

3.1.6 SR 3.8.4.5, SR 3.8.4.6, SR 3.8.4.7, SR 3.8.4.8, SR 3.8.4.9, and SR 3.8.4.10 The proposed change relocates the requirements SR 3.8.4.5 and SR 3.8.4.6 (visual inspection and connection resistance for vital and DG batteries), SR 3.8.4.7 (visual inspection for physical damage), SR 3.8.4.8 (remove visible corrosion and ensure that connections are clean and tight), and SR 3.8.4.9 and SR 3.8.4.10 (verification of connection resistance for vital and DG batteries) to the new Battery Monitoring and Maintenance Program (TS 5.7.2.21).

Technical Justification for SR 3.8.4.5, SR 3.8.4.6, SR 3.8.4.7, SR 3.8.4.8, SR 3.8.4.9, and SR 3.8.4.10 changes The TS require testing to be performed in accordance with SR 3.0.1. SR 3.0.1 states, in part, "Failure to meet Surveillance, whether such failure is experienced during the performance of the Surveillance or between performances of the Surveillance, shall be failure to meet the LCO."

Resistance verification SR 3.8.4.5 and SR 3.8.4.6 represent the minimum acceptable requirements for operability of required equipment. However, visual inspection of the battery terminals for signs of corrosion, as required by SR 3.8.4.5, SR 3.8.4.6, SR 3.8.4.7 and SR 3.8.4.8, to ensure that connections are clean and tight are generally considered a routine preventive maintenance activity. Visual inspection of the battery terminals 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. Therefore, TVA concludes that these activities are preventive maintenance and that the parameters can be adequately controlled in the new TS 5.7.2.21.

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With regard to the resistance verifications of SR 3.8.4.9 and SR 3.8.4.10, the existing values represent limits at which some action should be taken, not necessarily when the operability of the battery is in question. 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. 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.

Overall connection resistance has a direct impact on operability and is adequately determined by completion of the battery service or modified performance discharge tests. Therefore, these activities are more appropriately controlled under the proposed Battery Monitoring and Maintenance Program (TS 5.7.2.21).

3.1.7 SR 3.8.4.11 and 12 The proposed change renumbers SR 3.8.4.11 and SR 3.8.4.12 to SR 3.8.4.5 and SR 3.8.4.6, and modifies both allowed tests in each of the SRs. The first test allowance in the current SRs (SR 3.8.4.5 and SR 3.8.4.6 second test allowance) will now ensure that the charger is capable of supplying the minimum charging current at the minimum established float voltage for at least 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . The second test allowance (SR 3.8.4.5 and SR 3.8.4.6 second test allowance) adds acceptance criteria as to the time required to recharge the battery (24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ) and clarifies that during the recharging, the charger must also be supplying the largest combined demands of the various steady state loads in lieu of the current requirement to supply normal loads.

Furthermore, it states the start point of the test is after a discharge to the bounding design basis event discharge state, in lieu of the current requirement to start the test after a service or capacity discharge test. The proposed change also deletes the Notes for SR 3.8.4.11 and SR 3.8.1.12.

Technical Justification for TS SR 3.8.4.11 and SR 3.8.4.12 changes Renumbering SR 3.8.4.11 and SR 3.8.4.12 to SR 3.8.4.5 and SR 3.8.4.6 is editorial in nature, and will not result in new requirements or change operational restrictions or flexibility.

SR 3.8.4.11 and SR 3.8.4.12 (renumbered as SR 3.8.4.5 and SR 3.8.4.6) specifies battery charger current requirements for each DC source, and its purpose is to verify the design capacity of each battery charger. The voltage requirements are based on the battery charger voltage level after a response to a loss of AC power. Battery manufacturers establish this voltage limit to provide the optimum charge on the battery and to maintain the battery plates in a condition that supports maintaining the battery grid life. Maintaining this voltage limit should ensure that the battery will be capable of providing its designed safety function. Furthermore, the change to 2.07V for SR 3.8.6.3 and SR 3.8.6.6 requires battery pilot cells to be selected to represent the lowest voltage cells in the battery. This should ensure that the other cells are above the pilot cell voltage, which must remain above the TS limit.

The change also proposes to modify the alternate test method to SR 3.8.4.11 and SR 3.8.4.12 (renumbered as SR 3.8.4.5 and SR 3.8.4.6), which currently states:

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

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The proposed alternate test method is revised to:

"Verify each vital [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 current alternate method for verifying the design capacity of each battery charger may not be sufficient to demonstrate battery charger capability following the battery service test or capacity discharge test and may need to be supplemented with additional loads. The duration of this test may be longer than the charger sizing criteria since the battery recharge is affected by float voltage, temperature, and the exponential decay in charging current. If each battery charger is capable of recharging its respective battery 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 design minimum discharge state, the proposed alternate testing criteria would satisfy the purpose of SR 3.8.4.11 and SR 3.8.4.12.

SR 3.8.4.11 and SR 3.8.4.12 (renumbered as SR 3.8.4.5 and SR 3.8.5.6) are also revised to eliminate the following Notes:

SR 3.8.4.11 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."

SR 3.8.4.12 Note:

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

These restrictions are eliminated since WBN has spare chargers that can be placed in service in order to perform the two SRs for the normal chargers. The spare chargers are allowed to substitute for the normal chargers, as described in Section 3.1.1 above. Therefore, no restriction on performing these SRs during Modes 1, 2, 3, and 4 are required and at least one method of verifying charger OPERABILITY can be performed in MODE 1, 2, 3, or 4 without affecting plant safety.

3.1.8 SR 3.8.4.13 The proposed change renumbers SR 3.8.4.13 to SR 3.8.4.7 and revises Note 1 in SR 3.8.4.13 (new SR 3.8.4.7) to eliminate the "once per 60 months" limitation for satisfying the SR by performing the modified performance discharge test instead of the service discharge test.

Technical Justification for TS SR 3.8.4.13 change TVA proposed revising Note 1 to SR 3.8.4.13 (new SR 3.8.4.7) to eliminate the "once per 60 months" limitation for satisfying the SR by performing the modified performance discharge test instead of the service discharge test, effectively allowing the modified performance discharge test to be used instead of the service discharge test at any time. TVA has confirmed that the modified performance discharge test for the vital batteries completely encompasses the load profile of the battery service discharge test. TVA commits to confirming that the modified performance discharge test for the DG batteries completely encompasses the load profile of the battery service discharge test.

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3.1.9 SR 3.8.4.14 The proposed change moves SR 3.8.4.14 to TS 3.8.6, and renumbers it as SR 3.8.6.7. In addition, the proposed change deletes the Note restriction for performing the SR in Mode 1, 2, 3, or4.

Technical Justification for SR 3.8.4.14 change This change moves SR 3.8.4.14 to TS 3.8.6 and renumbers it as SR 3.8.6.7. In addition, the Note restriction for performing the SR in Mode 1, 2, 3, or 4, which only applies to the vital batteries, is being deleted. The purpose of SR 3.8.4.14 is to verify that the battery capacity for both the vital and DG batteries meet design requirements. Therefore, consistent with the requirements of SR 3.0.1, these surveillances are moved to TS 3.8.6. The proposed SR contains surveillance frequencies based on guidance provided in the IEEE Standard 450-2002 (Reference 3). These frequencies are based on the qualified life of safety-related batteries (typically 20 years) and known historical performance characteristics for vented lead-acid batteries. SR 3.8.6.7 surveillance frequencies will provide adequate data points for trending in order to determine the state-of-health of the safety-related batteries given the expected service life. The surveillance frequencies are appropriate given the condition of the battery, allows sufficient time for corrective actions to be taken, and is consistent with the safety significance of safety-related batteries.

The restriction for performing the test on the vital batteries is eliminated since WBN has a spare battery that can be used to meet the LCO requirement. This is shown in LCO 3.8.4 Note 1.

Thus, this spare battery can be placed in service in order to perform the vital battery SR for the normal batteries. Therefore, no restriction on performing this SR (new SR 3.8.6.7) during Modes 1, 2, 3, and 4 is required.

3.2 TS 3.8.5, DC Sources - Shutdown TVA proposes to revise TS 3.8.5 LCO Notes, Conditions, Required Actions, and SRs as described below.

3.2.1 LCO 3.8.5 LCO Notes The proposed change revises the Notes for LCO 3.8.5 to read:

1. Vital Battery V may be substituted for any required vital battery;

2. Spare Vital Battery Chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers;

3. Spare DG Battery Chargers WA1, 1 B1, 2A1, and 2B1 may be substituted for required DG chargers; and

4. 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.

Technical Justification for TS 3.8.5 LCO Notes change Existing Note 2 is renumbered Note 4. New Notes 2 and 3 allow substitution of the spare vital battery and DG battery chargers for the required battery chargers. The spare battery chargers are fully qualified and appropriately sized to perform their design safety function as those being E1-13 of 29

replaced. The description of the chargers, both normal and spare (also identified as alternate) is provided in Section 2.0 (Background) of this enclosure.

3.2.2 TS 3.8.5 Required Action A.2.4 and Condition B Required Action A.2.4 is modified to clarify that the Required Action is specific to the vital battery subsystem and not the DG electrical power subsystem. The proposed change adds the word "vital," such that the Required Action reads "...restore required vital DC electrical power subsystems to OPERABLE status."

Condition B is modified to address one "or more" required DG DC electrical power subsystem"s" inoperable. Currently, the Condition addresses "one" required DG DC electrical power subsystem inoperable.

Technical Justification for TS 3.8.5 Required Action A.2.4 and Condition B change Current Condition A is only applicable to the vital DC electrical power subsystems. Therefore, the added word "vital" in the Required Action is only providing alignment with the actual Condition. The Condition B addition ensures that proper actions are taken when more than one DG DC electrical power subsystems are required by the LCO and more than one are inoperable. The current Condition only applies to a single inoperability - no Actions are provided when multiple required DG DC electrical power subsystems are inoperable. In addition, LCO 3.0.3 is not applicable to this LCO, since the Applicability of TS 3.8.5 is Modes 5 and 6.

The proposed change clarifies that any time a DG DC electrical subsystem is inoperable, its associated DG is immediately declared inoperable, as stated in Required Action B.1.

Therefore, the proposed changes are editorial in nature and will not result in new requirements or change operational restrictions or flexibility.

3.2.3 SR 3.8.5.1 The proposed change would modify SR 3.8.5.1 to reflect the changes previously described in Section 3.1. Specifically, the SR numbers have been changed to reflect the deletion from Technical Specifications of SRs or renumbering of the SRs remaining in TS 3.8.4, as described in Section 3.1. Furthermore, SR 3.8.4.14 has been moved to TS 3.8.6, thus it is not necessary to provide an exception to this SR in this Specification.

Technical Justification for SR 3.8.5.1 change SR 3.8.5.1 is modified to be consistent with the proposed changes to TS 3.8.4. Revised SR 3.8.5.1 requires all Surveillances required by SR 3.8.4.1 through SR 3.8.4.7 to be met, which are all the SRs proposed to be included in TS 3.8.4. The exception to performing certain SRs, as allowed in the Note to the SR, identifies the same SRs as are in the current Note that are remaining in TS 3.8.4.

The proposed change meets 10 CFR 50.36 requirements for surveillances by ensuring that the necessary quality of systems and components is maintained and that the LCOs will be met.

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3.3 TS 3.8.6, Battery Parameters TVA proposes to revise TS 3.8.6 LCO, Conditions, Required Actions, and SRs. As part of these changes, battery float current monitoring is replacing specific gravity monitoring and a new TS Battery Monitoring and Maintenance Program is being added into TS Chapter 5.

3.3.1 TS 3.8.6 Title The proposed change revises the title of TS 3.8.6 from "Battery Cell Parameters" to "Battery Parameters."

Technical Justification for TS 3.8.6 Title change The revised TS 3.8.6 now includes parameters that are not individual battery cell parameters, but are for the entire battery (all cells). Therefore, the proposed change is editorial in nature and will not result in new requirements or change operational restrictions or flexibility.

3.3.2 TS 3.8.6 LCO The proposed change revises TS 3.8.6 LCO to delete the word "cell" and to require that the battery parameters for the "required" 125V vital batteries and 125V diesel generator (DG) batteries be within limits. In addition, the reference to Table 3.8.6-1 is deleted from the LCO statement.

Technical Justification for TS 3.8.6 LCO The change to delete the term "cell" is consistent with the change described in Section 3.3.1 above. The revised TS 3.8.6 includes parameters that are not individual battery cell parameters.

The change to add the word "required" is consistent with TS 3.8.4 and TS 3.8.5, in that LCO 3.8.4 Note 1 allows the alternate battery (Vital Battery V) to be used to meet the LCO requirements. Thus, the word "required" is added for consistency when there are more installed components than are required to meet the LCO.

The change deleting the reference to Table 3.8.6-1 is consistent with changes described and justified below in Section 3.3.4 below.

Therefore, these changes are editorial in nature.

3.3.3 TS 3.8.6 ACTIONS Note The proposed change deletes the term "bank" from the ACTIONS Note. Specifically, the ACTIONS Note will be changed from "Separate Condition entry is allowed for each battery bank" to "Separate Condition entry is allowed for each battery."

Technical Justification for TS 3.8.6 ACTION Note change The change is editorial in nature, in that WBN Unit 1 does not have battery "banks" nor do the actual Conditions refer to battery banks. Therefore, deletion of the term "bank" brings the ACTIONS Note into alignment with the actual (and revised) Conditions.

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3.3.4 TS 3.8.6 Table 3.8.6-1 The proposed change deletes Table 3.8.6-1, "Battery Cell Parameter Requirements" and moves the information to the new Battery Maintenance and Monitoring Program (new TS 5.7.2.21),

places the limits in new SRs or in new Required Actions, or relocates the information to licensee-controlled documents.

Technical Justification for TS 3.8.6 Table 3.8.6-1 changes TS Table 3.8.6-1 specifies the battery cell parameter requirements, including electrolyte level, float voltage, and specific gravity. TVA proposes deleting the table and moving the information to the new Battery Maintenance and Monitoring Program (new TS 5.7.2.21), placing the limits in new SRs or in new Required Actions, or relocating the information to licensee-controlled documents.

TVA proposes relocating the Category A and B values of TS Table 3.8.6-1 (including Notes a and b) and the Required Actions associated with restoring the cell parameters to within these limits (current TS 3.8.6 Action A and the first Condition in Condition B) to the Battery Monitoring and Maintenance Program. A new TS 5.7.2.21 will control this program, and TVA commits to place this information in the licensee-controlled program. The Category A and B values of TS Table 3.8.6-1 represent appropriate monitoring levels and appropriate preventive maintenance levels for long-term battery quality and extended battery life. Actions to restore deficient values will be implemented in accordance with the TVA's corrective action program.

Furthermore, the battery and its preventive maintenance and monitoring program are under the regulatory requirements of 10 CFR 50.65. This relocation will continue to assure that the battery is maintained at current levels of performance, and that operators appropriately focus on monitoring the battery parameters for degradation.

TVA proposes relocating the Category C specific limiting values of TS Table 3.8.6-1 for the battery electrolyte levels to the Battery Monitoring and Maintenance Program. However, new TS 3.8.6, Conditions E and F, will require the electrolyte temperature (pilot cell only) and level (any battery cell) to be greater than or equal to minimum established design limits. TVA proposes relocating the electrolyte temperature and level criteria (i.e., the minimum established design limits) to the Battery Monitoring and Maintenance Program. This program will be controlled as required by new TS 5.7.2.21, and TVA commits to place this information in a licensee-controlled program. Depending on the available excess capacity of the associated battery, the minimum temperature necessary to support operability of the battery can vary.

Relocating these values to the TS Battery Monitoring and Maintenance Program will provide TVA with added flexibility to monitor and control this limit at values directly related to the battery's ability to perform its assumed function.

TVA also proposes relocating the Category C specific limiting values of TS Table 3.8.6-1 for specific gravity to the Battery Monitoring and Maintenance Program. However, in lieu of relocating the specific gravity, TVA proposes to use float current monitoring to measure battery state of charge. This method is currently allowed by Table 3.8.6-1 Note c for up to 31 days following a battery recharge. This change will allow this method to be utilized on a permanent basis. Attachment 5 of this enclosure provides documentation from the battery manufacturer that if the float current for the vital batteries is < 2 amps and for the DG batteries is : 1 amp, the batteries are at least 98% recharged. TVA therefore commits to maintain a 2% design margin to provide assurance that the batteries are fully charged when the above float current limits are El-16 of 29

reached. In addition, TVA commits to revise the UFSAR to provide a description of this capability. For replacement batteries of a different model/size and/or manufacturer, float current limit changes will be verified as part of the design change documentation package for installing replacement batteries. TVA also commits to ensure that the instrumentation used to monitor float current under new SR 3.8.6.1 and SR 3.8.6.2 (which are described below in Section 3.3.12) will have the necessary accuracy and capability to measure electric currents in the expected range.

The proposed change discussed above will ensure that the battery parameters (maintenance, testing, and monitoring) are appropriately monitored and maintained in accordance with the TS Battery Monitoring and Maintenance Program.

3.3.5 TS 3.8.6 Actions A and C The proposed change adds new TS 3.8.6 Actions A and C to address what is currently the Category C limit for float voltage in TS Table 3.8.6-1. Current TS 3.8.6 Action B requires the battery to be immediately declared inoperable when this value is not met.

Technical Justification for TS 3.8.6 Actions A and C changes TVA proposes deleting Action B, as it refers to the Category C limit for float voltage, and adding new TS 3.8.6 Actions A and C to address what was formerly the Category C limit for float voltage in TS Table 3.8.6-1. These new Actions are applicable when one required vital battery (Action A) or DG battery (Action C) is found with one or more battery cells float voltage less than 2.07V. Actions A and C provide the Required Actions for the condition of a degraded battery cell. The Required Actions are to perform within 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months s: (a) SR 3.8.4.1 or SR 3.8.4.2 - verify the battery terminal voltage is greater than or equal to the minimum established float voltage (Required Actions A.1 and C.1, respectively); and (b) SR 3.8.6.1 or SR 3.8.6.2 - verify each battery's float current is less than or equal to 2 amps for the vital batteries and less than 1 amp for the DG batteries (Required Actions A.2 and C.2, respectivelyl). The above actions ensure that there is still sufficient capacity for the battery to perform its intended function. Provided the above actions are met, Required Actions A.3 and C.3 will allow continued operation for up to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to allow the restoration of the affected cell(s) voltage to greater than or equal to 2.07V.

The TVA commitment to incorporate the minimum established float voltage limit into the plant's UFSAR provides reasonable assurance that the value will be appropriately maintained by TVA to accurately reflect the design of the plant.

3.3.6 TS 3.8.6 Actions B and D The proposed change adds new TS 3.8.6 Actions B and D to address battery state of charge.

Current TS 3.8.6 Action B requires the battery to be immediately declared inoperable when the current state of charge Category C limit in Table 3.8.6-1 is not met.

Technical Justification for TS 3.8.6 Actions B and D change TVA proposes deleting Action B, as it refers to the category C limit on specific gravity, and adding new TS 3.8.6 Actions B and D to address battery state of charge. These new Actions are applicable when one required vital battery (Action B) is found with float current greater than 2 amps or one required DG battery (Action D) is found with float current greater than 1 amp. A float current of greater than 2 amps for the vital batteries and 1 amp for DG batteries provides indication that a partial discharge has occurred. The Required Actions (Required Actions B.1 E1-17 of 29

and D.1) are to verify within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months that the battery terminal voltage is greater than or equal to the minimum established float voltage (SR 3.8.4.1 and SR 3.8.4.2, respectively), thus confirming battery charger operability. If the terminal voltage is satisfactory and there are no battery cells with voltage less than 2.07V, Required Actions B.2 and D.2 require that within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months the battery be restored to its fully-charged condition (i.e., < 2 amps for the vital battery and < 1 amp for the DG battery) from any discharge that might have occurred due to a temporary loss of the battery charger.

If the terminal voltage is found to be less than the minimum established float voltage, it indicates that the battery charger is either inoperable or is operating in the current limit mode. If the 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 battery has been substantially discharged and likely cannot perform its required design functions. In this case, new Condition H would be entered. This Action requires the associated battery to be immediately declared inoperable, which is consistent with current Action B.

3.3.7 TS 3.8.6 Action E The proposed change adds new TS 3.8.6 Action E to address the level of the electrolyte in a cell. Current TS 3.8.6 Action A provides the actions when electrolyte level does not meet the category A and B limits, and requires verification the level is above the top of the plates within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and to restore the level to within limits in 31 days.

Technical Justification for TS 3.8.6 Action E change TVA proposes adding new TS 3.8.6 Action E to address the electrolyte level in a cell. This new Action E is applicable when one required vital or DG battery is found with one or more cells with an electrolyte level less than the minimum established design limits. If the electrolyte level is above the top of the battery 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 could be considered operable. With the electrolyte level below the top of the plates, there is a potential for dry-out and plate degradation. New Required Actions E.1 and E.2 (as well as provisions in the new Battery Monitoring and Maintenance Program) will restore the electrolyte level to above the plates within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months (Required Action E. 1), ensure that the cause of the loss of the 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 (Required Action E.2), and equalize and test the battery cells that have been discovered with an electrolyte level below the top of the plates in accordance with the Battery Monitoring and Maintenance Program. The new proposed Required Actions will, therefore, ensure the batteries will be restored to an operable condition in a timely manner. In addition, Required Action E.3 requires the battery electrolyte level to be restored to greater than or equal to the minimum established design limits within 31 days.

3.3.8 TS 3.8.6 Action F The proposed change adds new TS 3.8.6 Action F which applies to a battery found with a pilot cell electrolyte temperature less than the minimum established design limit. Current TS 3.8.6 Action B requires the battery to be immediately declared inoperable when a pilot cell electrolyte temperature is not within limits.

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Technical Justification for TS 3.8.6 Action F change TVA proposes adding new TS 3.8.6 Action F which applies to a battery found with a pilot cell electrolyte temperature less than the minimum established design limit. A low electrolyte temperature limits the current and power available from the battery. This new Action F is applicable when one required vital or DG battery is found with a pilot cell electrolyte temperature less than the minimum established design limits. Proposed TS 3.8.6 Required Action F.1 requires the electrolyte pilot cell temperature to be restored 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 . The TVA batteries are sized with correction margins to account for factors affecting performance that include temperature and aging and adequate battery design margins. As a consequence, TVA commits to periodically monitor battery room temperature such that a battery room temperature excursion could reasonably expect to be detected and corrected prior to the average battery electrolyte temperature dropping below the minimum electrolyte temperature. The battery rooms are contained in a separate environmentally controlled area outside the engineered safety feature switchgear rooms. The temperature of the room containing the batteries is currently monitored at least every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months during operator tours. If battery room temperature were to decrease below administrative limits, TVA will implement corrective measures to restore battery room temperature in accordance with plant procedures.

Historic data indicate that temperature deviation between cells in a given battery have not deviated more than 30 F between the highest and lowest temperature cell. This meets IEEE 450-2002 recommendation that the maximum temperature deviation across the battery not exceed a maximum of 50 F.

Based on these considerations and the fact that batteries have very large thermal inertia, it is highly likely that a room temperature excursion would be corrected prior to the battery electrolyte reaching its maximum or minimum design temperature.

3.3.9 TS 3.8.6 Action G The proposed change adds new TS 3.8.6 Action G to addresses the condition in which two or more redundant batteries (i.e., two or more vital batteries or two or more DG batteries) have battery parameters that are not within limits. Currently, TS 3.8.6 Action B requires a battery to be immediately declared inoperable under this condition.

Technical Justification for TS 3.8.6 Action E change TVA proposes adding new TS 3.8.6 Action G to address the condition in which more than one required vital or DG battery has battery parameters not within the limits specified in Conditions A through F. If this condition exists, there is not sufficient assurance that the batteries will be capable of performing their intended safety function. With redundant batteries involved, loss of function is possible for multiple systems that depend upon the batteries. Proposed Required Action G.1 requires the affected battery parameters be restored to within limits within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

The 2-hour time period is consistent with similar LCOs established by the TS (i.e., TS 3.8.9 Distribution Systems - Operating) and is reasonable considering the potential for loss of function of components that depend on the batteries (e.g., AC vital bus subsystem(s), electrical breaker control/position indication power). Accordingly, a relatively short duration is provided to resolve the condition with minimum risk.

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3.3.10 TS 3.8.6 Action H The proposed change deletes existing Action B and replaces it with new Action H.

Technical Justification for TS 3.8.6 Action B change Existing Condition B describes three Conditions of battery cell parameter inoperability. These conditions are:

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

2. One or more batteries with average electrolyte temperature of the representative cells

< 60OF for vital batteries and < 50°F for DG batteries; and

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

If any of these conditions are met, then existing Required Action B.1 requires the associated battery to be immediately declared inoperable. New Action H provides a default condition for battery parameters that fall outside the allowance of the Required Actions for new Conditions A, B, C, D, E, F, and G. Failure to meet any of the Required Actions of new Conditions A through G effectively encompass the existing conditions described above (in items 1, 2, and 3).

Under these conditions, it is assumed that there is insufficient capacity to supply the maximum expected load requirements. New Condition H also addresses the case where one required vital battery or one required DG battery with one or more battery cells float voltage less than 2.07V and a float current greater than 2 amps for the vital batteries or greater than 1 amp for the DG batteries. Since battery capacity may be incapable of performing the intended design function, new Required Action H.1 requires the associated battery to be immediately declared inoperable.

3.3.11 SR 3.8.6.1, SR 3.8.6.2, and SR 3.8.6.3 The proposed change deletes requirements in a) SR 3.8.6.1 to verify battery cell parameters meet TS Table 3.8.6-1 Category A limits; b) SR 3.8.6.2 to verify battery cell parameters meet Table 3.8.6-1 Category B limits and c) SR 3.8.6.3 to verify average electrolyte temperature of representative cells is > 60°F for vital batteries and > 50°F for the DG batteries.

Technical Justification for SR 3.8.6.1, SR 3.8.6.2, and SR 3.8.6.3 change The elimination of existing SR 3.8.6.1 and SR 3.8.6.2 is consistent with the elimination of TS Table 3.8.6-1. The Category A and B values of TS Table 3.8.6-1 for electrolyte level, individual battery cell float voltage, and specific gravity and the remedial actions associated with restoring a battery to operable status are moved to the new Battery Monitoring and Maintenance Program. The Category A and B values of TS Table 3.8.6-1 represent appropriate monitoring levels and appropriate preventive maintenance levels for long-term battery quality and extended battery life. Relocating these battery cell parameters to the Battery Monitoring and Maintenance Program is acceptable because (1) battery capacity is considered adequate when electrolyte level is above the top of the plates; (2) an individual battery cell float voltage criterion of greater than or equal to 2.13V is a maintenance limit; and (3) specific gravity measurement criteria are being replaced by float current monitoring which satisfies the intent of the existing SRs.

Additionally, assurance that these relocated battery cell values will continue to be controlled at their current level, and that actions to restore deficient values will be implemented according to TVA corrective action program.

E1-20 of 29

Furthermore, the battery and its preventive maintenance and monitoring program are under the regulatory requirements of 10 CFR 50.65. This relocation will continue to assure that the battery is maintained at current levels of performance, and that operators appropriately focus on monitoring the battery float current and voltage for indication of degradation.

Existing SR 3.8.6.3 will be replaced with new SR 3.8.6.5 (see Section 3.3.16 below).

The proposed change discussed above ensures the battery parameters (maintenance, testing, and monitoring) are appropriately monitored and maintained in accordance with the Battery Monitoring and Maintenance Program, as specified in TS Section 5.7.2.21.

Therefore, deletion of SR 3.8.6.1, SR 3.8.6.2, and SR 3.8.6.3 (which is replaced by SR 3.8.6.5),

relocation of Category A and B values, and the new SRs described in the following sections provide assurance that battery quality and operability will continue to be maintained.

3.3.12 New SR 3.8.6.1 and SR 3.8.6.2 The proposed change adds new SR 3.8.6.1 and SR 3.8.6.2.

Technical Justification for New SR 3.8.6.1 and SR 3.8.6.2 change TVA proposes adding new SR 3.8.6.1 and SR 3.8.6.2, which require verification every 7 days that the float current for each vital battery is less than or equal to 2 amps and that each DG battery is less than or equal to 1 amp. In addition, a Note states that the limit is not required to be met when the associated .battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.1 (for the vital batteries) and SR 3.8.4.2 (for the DG batteries). The purpose of the SRs 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 for the vital batteries and less than or equal to 1 amp for the DG batteries) 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 stated above in Section 3.3.4 above, the use of float current to determine the state of charge of the battery is consistent with the battery manufacturer recommendations. The Note is acceptable since when the float voltage is not maintained, the Required Actions of TS 3.8.4 Action A or E are being taken, which provide the appropriate and necessary verifications of the battery condition.

3.3.13 New SR 3.8.6.3 The proposed change adds new SR 3.8.6.3.

Technical Justification for New SR 3.8.6.3 change TVA proposes adding new SR 3.8.6.3, which requires verification every 31 days that the float voltage of pilot cells for the vital and DG batteries is greater than or equal to 2.07V. This voltage level represents the minimum acceptable voltage for operability. The Battery Monitoring and Maintenance Program in new TS Section 5.7.2.21 includes actions to restore battery cells with float voltage less than 2.13V and actions to verify that the remaining cells are greater than or equal to 2.07V when a cell or cells have been found to be less than 2.13V. The 31 day frequency provides reasonable assurance that the battery can perform its intended safety E1-21 of 29

function while providing a reasonable time between surveillances to allow appropriate corrective actions consistent with the safety significance of safety-related batteries.

3.3.14 New SR 3.8.6.4 The proposed change adds new SR 3.8.6.4.

Technical Justification for New SR 3.8.6.4 change TVA proposes adding new SR 3.8.6.4, which requires verification every 31 days that the electrolyte level of each individual cell in the vital and DG battery is greater than or equal to the minimum established design limits. 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.

TVA also proposes relocating the specific limiting values for the battery electrolyte level that are in current TS Table 3.8.6-1 to the Battery Monitoring and Maintenance Program, as described and justified in Section 3.3.4 above. SR 3.8.6.4 would require the electrolyte level to be greater than or equal to the "minimum established design limits." Relocation to the Battery Monitoring and Maintenance Program will allow flexibility to monitor and control this limit at values directly related to the battery's ability to perform its required safety function. Incorporating the minimum established design level limit into the plant's UFSAR provides reasonable assurance that the value will be appropriately maintained to accurately reflect the design of the plant.

3.3.15 New SR 3.8.6.5 The proposed change adds new SR 3.8.6.5.

Technical Justification for New SR 3.8.6.5 change TVA proposes adding new SR 3.8.6.5, which requires verification every 31 days that the temperature of each vital and DG battery pilot cell is greater than or equal to the minimum established design limits. This SR replaces existing SR 3.8.6.3, which requires verifying the average (versus pilot cell) electrolyte temperature every 92 days. Batteries have very large thermal inertia, the batteries are designed with margins to account for factors affecting performance (i.e., temperature and aging), and there is monitoring to maintain optimum battery room temperatures. As a result, the pilot cell temperature is a valid representation of the temperature of the battery and is adequate to ensure that the minimum electrolyte temperature is maintained. The surveillance frequency of 31 days is consistent with the recommendations provided in IEEE Std. 450-2002 (Reference 2).

TVA also proposes relocating the specific limiting values for the battery electrolyte temperature to the Battery Monitoring and Maintenance Program. Proposed SR 3.8.6.5 requires the electrolyte temperature to be greater than or equal to the "minimum established design limits."

Depending on the available excess capacity of the associated battery, the minimum temperature necessary to support operability of the battery can vary. Relocation to the Battery Monitoring and Maintenance Program will allow flexibility to monitor and control this limit at values directly related to the battery ability to perform its intended function. Incorporating the minimum established design temperature limit into the plant's UFSAR also provides reasonable assurance that the value will be appropriately maintained to accurately reflect the design of the plant.

E1-22 of 29

3.3.16 New SR 3.8.6.6 The proposed change adds new SR 3.8.6.6.

Technical Justification for New SR 3.8.6.6 change TVA proposes adding new SR 3.8.6.6, which requires verification every 92 days that the float voltage of all connected cells for the vital and DG batteries is greater than or equal to 2.07 V per cell (Vpc). The voltage specified in this SR represents the point at which battery operability cannot be assured. Optimal long term battery performance is obtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This provides adequate over-potential, which limits the formation of lead sulfate and self discharge, which could eventually render the battery inoperable. Float voltages in this range or less, but greater than 2.07 Vpc, are addressed in the Battery Monitoring and Maintenance Program. Furthermore, the Battery Monitoring and Maintenance Program includes actions to restore battery cells with float voltage less than 2.13 Vpc and actions to verify that the remaining cells are greater than or equal to 2.07 Vpc when a cell or cells have been found to be less than 2.13 Vpc. The 2.07 Vpc limit reflects the Operability limit for the batteries. With all battery cells above 2.07 Vpc, there is adequate assurance that the terminal voltage is at an acceptable threshold for establishing battery operability.

3.3.17 New SR 3.8.6.7 The proposed change moves the battery capacity test from existing SR 3.8.4.14 to new SR 3.8.6.7.

Technical Justification for New SR 3.8.6.7 change See Section 3.1.9 above for the technical justification.

3.4 TS 5.7.2.21, Battery Monitoring and Maintenance Program The proposed change would add a new Battery Monitoring and Maintenance Program requirements as TS 5.7.2.21.

Technical Justification for new TS 5.7.2.21 TVA proposes new TS 5.7.2.21, "Battery Monitoring and Maintenance Program," to read as follows.

Battery Monitoring and Maintenance Program This program provides controls for battery restoration and maintenance. The program shall be in accordance with the IEEE Std. 450-2002, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," as endorsed by RG 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.

E1-23 of 29

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 RG 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 < 2.13V;

2. Actions to determine whether the float voltage of the remaining battery cells is > 2.13V when the float voltage of a battery cell has been found to be < 2.1.3V;

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.

Monitoring of the current battery parameters (i.e., specific gravity, electrolyte level, cell temperature, float voltage, connection resistance, and physical condition) will be relocated to this program. The Battery Maintenance and Monitoring 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.

The TS 5.7.2.21 Battery Monitoring and Maintenance 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 TVA corrective action program. Furthermore, the battery and its preventive maintenance and monitoring program continue to be subject to the regulatory requirements of 10 CFR 50.65.

3.5 Conclusion The proposed changes update the WBN Unit 1 to be consistent with TSTF-360 and TSTF-500, as the WBN Unit 1 design allows. While this amendment request does not use the NRC Model Safety Evaluation provided for TSTF-500 as the basis for this change, TVA reviewed E1-24 of 29

Section 2.2 of the model application and has included all applicable information requested by the NRC in this section. Furthermore, Section 2.2 of the model application included other verifications and requested changes to the UFSAR. TVA is providing commitments to ensure the requested verifications and UFSAR changes are made prior to implementing the changes requested in this License Amendment Request (LAR). The list of commitments is provided in to this LAR.

The TVA process governing the processing and submittal of TSs changes and License Amendment Requests requires that the appropriate organizations (e.g., Operations, Training, Engineering, Maintenance, Chemistry, Radiation Protection, and Work Control) identify the documents that are affected by each proposed change to the TSs and Operating Licenses.

Among the items that are considered are training, plant modifications, procedures, special implementation constraints, design documents, surveillance instructions associated with TSs SRs, Technical Requirements Manual, TSs Bases, and UFSAR. The process requires that procedures and design document changes necessary to support TSs Operability are approved prior to implementation of the license amendment. The process also provides assurance that the remaining changes, if any, are scheduled tracked for configuration control.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria The proposed changes, in this amendment request, do not alter or revise onsite DC power systems at WBN which are designed to comply with the following applicable regulations and requirements:

10 CFR 50, Appendix A, General Design Criterion (GDC) 2, "Design Bases for Protection Against Natural Phenomena";

10 CFR 50, Appendix A, GDC 4, "Environmental and Dynamic Effects Design Bases";

10 CFR 50, Appendix A. GDC 5, "Sharing of Structures, Systems, and Components";

10 CFR 50, Appendix A, GDC 17, "Electric Power Systems";

10 CFR 50, Appendix A, GDC 18, "Inspection and Testing of Electric Power Systems";

10 CFR 50, Appendix A, GDC 50, "Containment Design Basis";

Regulatory Guide (RG) 1.6, Revision 0, "Independence Between Redundant Standby (Onsite)

Power Sources and Between their Distribution Systems";

RG 1.32, Revision 2, "Criteria for Safety-Related Electric Power Systems for Nuclear Plants";

RG 1.53, Revision 0, "Application of the Single-Failure Criterion to Nuclear Power Plant Protection Systems";

RG 1.63, Revision 2, "Electric Penetration Assemblies in Containment Structures for Water-Cooled Nuclear Power Plants";

RG 1.75, Revision 2, "Physical Independence of Electric Systems";

E1-25 of 29

RG 1.81, Revision 1, "Shared Emergency and Shutdown Electric Systems for Multi-Unit Nuclear Power Plants";

RG 1.93, Revision 0, "Availability of Electric Power Sources";

RG 1.118, Revision 2, "Periodic Testing of Electric Power and Protection Systems";

RG 1.128, Revision 0, "Installation Design and Installation of Large Lead Storage Batteries for Nuclear Power Plants";

RG 1.129, Revision 1, "Maintenance, Testing, and Replacement of Large Lead Storage Batteries for Nuclear Power Plants";

RG 1.153, Revision 0, "Criteria for Power, Instrumentation, and Control Portions of Safety Systems";

RG 1.155, Revision 1, "Station Blackout"; and RG 1.160, Revision 2, "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants."

With the implementation of the proposed change, WBN Unit 1 will continue to meet the applicable regulations and requirements.

4.2 Precedent An acceptance review in accordance with LIC-1 09 was issued for the following plants: Arkansas Nuclear One, Units 1 and 2, and Palo Verde, Units 1, 2 and 3. Both sites submitted TS changes based on the model application contained in TSTF-500. The proposed TS changes for those plants were based on the DC electrical power distribution model referenced in the Bases for NUREG-1431, Revision 3.1, and only required that the licensee provide technical and regulatory justification for those changes that deviated from the model application. Because WBN Unit 1 DC electrical power distribution system is significantly different from that referenced in the model application, TVA is submitting a stand-alone LAR that provides the technical and regulatory justification for all TS changes to TS 3.8.4, 3.8.5, and 3.8.6.

4.3 Significant Hazards Consideration The proposed changes will modify WBN, Unit 1 Technical Specification (TS) requirements related to direct current (DC) electrical systems in TS 3.8.4, "DC Sources - Operating," TS 3.8.5, "DC Sources - Shutdown," and TS 3.8.6, "Battery Cell Parameters." In addition, a new "Battery Monitoring and Maintenance Program" is being proposed for Technical Specification 5.7.2.21.

The proposed TS changes place requirements on the battery itself rather than the battery cells as currently required.

TVA has concluded that the changes to WBN Unit 1 TS 3.8.4, TS 3.8.5, and TS 3.8.6 do not involve a significant hazards consideration. TVA's conclusion is based on its evaluation in accordance with 10 CFR 50.91 (a)(1) of the three standards set forth in 10 CFR 50.92, "Issuance of Amendment," as discussed below:

E1-26 of 29

Does the proposed amendment involve a significant increase in the probability or consequences of any accident previously evaluated?

Response: No.

The proposed changes restructure the Technical Specifications (TS) for the direct current (DC) electrical power system and are consistent with Technical Specifications Task Force (TSTF) change TSTF-360, Revision 1 and TSTF-500, Revision 2. The proposed changes modify TS Actions relating to battery and battery charger inoperability. The DC electrical power system, including associated battery chargers, is not an initiator of any accident sequence analyzed in the Updated Final Safety Analysis Report (UFSAR). Rather, the DC electrical power system supports equipment used to mitigate accidents. The proposed changes to restructure TS and change surveillances for batteries and chargers to incorporate the updates included in TSTF-360, Revision 1 as updated by TSTF-500, Revision 2, will maintain the same level of equipment performance required for mitigating accidents assumed in the UFSAR. Operation in accordance with the proposed TS would ensure that the DC electrical power system is capable of performing its specified safety function as described in the UFSAR.

Therefore, the mitigating functions supported by the DC electrical power system will continue to provide the protection assumed by the analysis. The relocation of preventive maintenance surveillances, and certain operating limits and actions, to a licensee controlled Battery Monitoring and Maintenance Program will not challenge the ability of the DC electrical power system to perform its design function. Appropriate monitoring and maintenance that are consistent with industry standards will continue to be performed. In addition, the DC electrical power system is within the scope of 10 CFR 50.65, "Requirements for monitoring the effectiveness of maintenance at nuclear power plants," which will ensure the control of maintenance activities associated with the DC electrical power system.

The integrity of fission product barriers, plant configuration, and operating procedures as described in the UFSAR will not be affected by the proposed changes. Therefore, the consequences of previously analyzed accidents will not increase by implementing these changes.

Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed changes involve restructuring the TS for the DC electrical power system.

The DC electrical power system, including associated battery chargers, is not an initiator to any accident sequence analyzed in the UFSAR. Rather, the DC electrical power system supports equipment used to mitigate accidents. The proposed changes to restructure the TS and change surveillances for batteries and chargers to incorporate the updates included in TSTF-360 Revision 1 as updated by TSTF-500, Revision 2, will maintain the same level of equipment performance required for mitigating accidents assumed in the UFSAR. Administrative and mechanical controls are in place to ensure E1-27of29 .

the design and operation of the DC systems continues to meet the plant design basis described in the UFSAR.

Therefore, the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No.

The margin of safety is established through equipment design, operating parameters, and the setpoints at which automatic actions are initiated. The equipment margins will be maintained in accordance with the plant-specific design bases as a result of the proposed changes. The proposed changes will not adversely affect operation of plant equipment. These changes will not result in a change to the setpoints at which protective actions are initiated. Sufficient DC capacity to support operation of mitigation equipment is ensured. The changes associated with the new battery Maintenance and Monitoring Program will ensure that the station batteries are maintained in a highly reliable manner.

The equipment fed by the DC electrical sources will continue to provide adequate power to safety-related loads in accordance with analysis assumptions. TS changes made to be consistent with the changes in TSTF-360, Revision 1, as updated by TSTF-500, Revision 2, maintain the same level of equipment performance stated in the UFSAR and the current TSs.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

4.4 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR Part 20, and would change an inspection or surveillance requirement. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

E1-28 of 29

6.0 REFERENCES

1. TSTF-360, Revision 1, "DC Electrical Rewrite."

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

3. IEEE Standard 450-2002, "IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications," The Institute of Electrical and Electronics Engineers, Inc.

4. WBN Unit 1, UFSAR Section 8.3.1, "AC Power System."

5. WBN Unit 1, UFSAR Section 8.3.2, "DC Power System."

E1-29 of 29

ATTACHMENT I Proposed WBN Unit I TS Changes (Markups)

Al-1

DC Sources - Operating 3.8.4 3.8 ELECTRICAL POWER SYSTEMS 3.8.4 DC Sources - Operating LCO 3.8.4 Four channels of vital DC and four Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE.

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

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

2. Spare Vital Chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required Vital chargers.

3. Spare DG Chargers 1A1, 1B1, 2A1, or 2B1 may be substituted for required DG chargers.

24. 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.

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

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

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

AND A.3 Restore vital battery charger 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to OPERABLE status.

B. One required vital battery B.1 Restore vital battery to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable. OPERABLE status.

AC. One required vital DC AC.1 Restore vital DC eleetFieal- 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months ectFic*al powerF sbsystemchannel to sub6ysteinchannel OPERABLE status.

inoperable for reasons other than Condition A or B.

BD. Required Action and BD.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion AND Time of Condition A, B or C not met. 9D.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

DC Sources - Operating 3.8.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. One required DG battery E.1 Restore DG battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months charger inoperable, voltage to greater than or equal to the minimum established float voltage.

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

< 1 amp.

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

F. One required DG battery F.1 Restore DG battery to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable. OPERABLE status.

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

other than Condition E or F.

1H. Required Action and 14H.1 Declare associated DG Immediately associated Completion inoperable.

Time of Condition GE, F, or G not met.

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-' 128 V (132 V for vital batteiy-V-Gn float ehargevoltage.

SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 days equal to the minimum established --1-24-V-enfloat -

GhaFevoltage.

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 125V DC distribution panel and associated battery charger.

(continued)

Watts Bar-Unit 1 3.8-25

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.84.5 Vori.fy no visible corroslon at term!ials and connectors for the "ital batteiors.

QR Verify G.n.e.t-*.*.. resistane* for the vital batteries is

_ 80 E 6 ohm for inter col connectiGons, < 50 E 6 ohm for inter rack connetons,

120 E 6 ohm-fo;r intrtier frntr ,and rconnect 50 E 68oh - for teminfal GGAReGtGR Verify no Visibble corroion69- at ter~minals and coennectors- 92-dayS for the; DG batteries.

OR Verify connection resistanco for the DG batteries is t 80 E 6 ohm for inter Goil cnnection, 50=E f 6 ohm3, fnor inter tier cnnections, and 50 Em 6 ohm for terminal connections.

SR 3.9.4.7-Verify batte~' cells, coil' plates, and racks Show no 1: m visual idctOn f physical damage or abnormal SR~&4Remoeve vfisfible termninal corrosion and verify batter; 1-2 menths cGell to cell and teirminOa.l cnecin are cAPted wieth antR~iwcor.Arosion m~aterial.

(continued Watts Bar-Unit 1 3.8-26

DC Sources - Operating 3.8.4 SURVEILLANCE FREQUENCY Verif.. connection rosistAnco for the vital batteries is 12 menths 4 80 E-6 ohmfrA Wno ce911 connotions - 50 E 6R forF inter rack connections, *120 E 6Rohm forintr tier-connections, aRnd

50 E 6 ohm for termin.al G0RR9GtGA

&R 2_84WQ Vorify connec-tioresitac for the DG batteries6 1-2 menthi

<- 8_0 EM-"*

6 hRm- fo-r iRter cellII connections, - 50 E 6 ohm fmor inter tier co Gnnecti8nS, and _'-50EF-6ohm for terminal connections.

SR 3.8.4.14-5 NOTE Thio Sur-,eillnce is normally not peF....,d in MODE 1, 2, 3, o-r 4. HoWeer, cedit mRay be taken for unplanned events that satisfy this SR.

Verify each vital battery charger is Gapable ef 18 months recharging its associated batter'; from a srioo capacity discharge test while supplying normal lead6supplies > 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 .

OR Verify each vital battery charger 0s-eapable-of operating for >_4 ho-urs- at courrent limnit 2:20 :250 aa4Wan 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.

(continued)

Watts Bar-Unit 1 3.8-27 Amendment 54

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.426 NOTE Credit may be taken for Uplannod -ventsthat satisfy this SR.

Verify each diesel-geRe.,ateDG battery charger 18 months supplies > 20 amps at greater than or equal to the minimum established float voltage for > 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months sis-cGipable Of FeGaiig!RiyI its GGOiat JJLtte tFE)ri a

-c se orcpacity dischargo test While supplying eFFnal ead* .

OR 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.

SR 3.8.4.47 ----------------------- NOTES----------------

1. The modified performance discharge test in SR 3.8.46.447 may be performed in lieu of the-SerVice test in SR 3.8.4.-37 once per 69 mn,,ths.

2. This Sueilae iot performIed, in MODE ,, 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 3.8-28 Amendment 12

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.!4 NOTES T-hi6 Survoillance8 i ot po~formFed in MODE 1, 2, 3, or 4 for required vita' batteries. Credit may be takon for unplanned eVRnts that satisfy this SR.

Vorify batter' capacity is Ž; 80% of themanufactuor's 6-fnectuhs r-ating when subjoctod to a po4ormaRce discharge torst-ormoifed oformanco discharge test- AND 12 months when dogradation Or has reac hed 85% of*

expected lifo wth-capacity 4100% Of batte,-y rhes w6h mfanRufacturor'srating ANQ 24 meonths;i.when batter; has reached 85% of expocted lifo with capacit" ý 100%

of mnanufacturer's Watts Bar-Unit 1 3.8-29 Amendment 12

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."

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

2.* Spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers.

3. Spare DG chargers 1Al, 1B1, 2A1, or 2B1 may be substituted for required DG chargers.

24. 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 subsystems.

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

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

subsystems inoperable.

OR A.2.1 Suspend CORE Immediately ALTERATIONS.

AND A.2.2 Suspend movement of Immediately irradiated fuel assemblies.

(continued)

Watts Bar-Unit I 3.8-30

DC Sources-Shutdown 3.8.5 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. (continued) AND A.2.3 Initiate action to suspend Immediately operations involving positive reactivity additions.

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

B. One or more required DG B.1 Declare associated DG Immediately DC electrical power inoperable subsystems inoperable.

Watts Bar-Unit 1 3.8-31

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

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

The following SRs are not required to be performed: SR 3.8.4.14_5, SR 3.8.4.4-26, SR 3.9.4137-, and SR 3.8.4.4-47.

For DC sources required to be OPERABLE, the In accordance with following SRs are applicable: applicable SRs SR 3.8.4.1 SR 3.8.4.6 SR 3.8.4.2 SR 3.8.4.7 SR 384.14 SR 3.8.4.3 SR 3.8.4.9 SR 3.8.4.4 SR 3.8.4.5 SSR R 3.9.4!.!

3.9..1 Watts Bar-Unit 1 3.8-32

Battery GeU-Parameters 3.8.6 3.8 ELECTRICAL POWER SYSTEMS 3.8.6 Battery Gell-Parameters I LCO 3.8.6 Battery Gell-parameters for required 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within the limits of Table 3.6.41.

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

ACTIONS

NOTE-Separate Condition entry is allowed for each battery-baRk.

CONDITION REQUIRED ACTION COMPLETION TIME A. Onie or moroe bhattorioc with A. I Vorify pilot c8l16 oloctrolyto8e one Or moroe batter,' coil level -and-float voltage mooet parametere not Within Table 3.8.69 1Catogor,' C Catogor,' A or B lim~itS.

At4P A.2 Verify battery cel! paFa*m*otr, :24-he-w mnoot Table 3-8.65 1 Categor C (nnAND theeaftef AND A.3 Rectoro batter,' cell 3-1 days parameterc to Category A and liits oaf Table 3861 (continued)

Watts Bar-Unit 1 3.8-33

Battery GeII-Parameters 3.8.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B A.Rouirod Action and I13 Declare associatod battery Immediately associated Completion iniepeFable.

Timo of Condition A not Ono or mrenr- bhatteries with aVorage oloctrolye temper1ture of the representative cells 4-0 'F-for vital batterIes and - 502P for DG ba4tteres OnA or more batteries; with one or mo-re battwGerol!

parametes net Withi Category C values. I_________________ I_________

[Replace Actions with Insert 1 (TS 3.8.6 ACTIONS)I.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6. 1. Veiy battery sell parameters mteet Table 3.8.6 1 7udaed Category A lmts (continued)

Wafts Bar-Unit 1 3.8-34

Battery Ge4-Parameters 3.8.6 Insert 1 - TS 3.8.6 Actions ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One required vital battery 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 with one or more battery cells float voltage < 2.07 V. AND 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 float 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months voltage > 2.07 V.

B. One required vital battery B.1 Perform SR 3.8.4.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months with float current > 2 amps.

AND B.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.

C. One required DG battery 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 with one or more battery cells float voltage < 2.07 V. AND 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months C.2 Perform SR 3.8.6.2. 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months AND C.3 Restore affected cell float voltaqe > 2.07 V.

DD. One required DG battery 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 with float current > 1 amp.

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

E. One required battery ------------------- NOTE -----------

with one or more cells with Required Actions E.1 and E.2 are only electrolyte level less than applicable if electrolyte level was below minimum established the top of plates.

design limits.

E.1 Restore electrolyte level to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months above top of plates.

AND Watts Bar-Unit 1 Inserts for Page 3.8-34

Battery GeN-Parameters 3.8.6 CONDITION REQUIRED ACTION COMPLETION TIME E.2 Verify no evidence of leakage. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months AND E.3 Restore electrolyte level to 31 days greater than or equal to minimum established design limits.

F. One required battery F.1 Restore battery pilot cell 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months with Pilot cell electrolyte temperature to greater than or temperature less than equal to minimum established minimum established desiqn limits.

design limits.

G. More than one required vital G.1 Restore battery parameters to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months batteries with battery within limits.

parameters not within limits.

OR More than one reguired DG batteries with battery parameters not within limits.

H. Required Action and B.1 Declare associated battery Immediately associated Completion inoperable.

Time of Condition A, B, C.

D, E. F or G not met.

OR One required vital battery with one or more battery cells float voltage < 2.07 V and float current > 2 amps.

OR One required DG battery with one or more battery cells float voltage < 2.07V and float current> 1 amp. II Watts Bar-Unit 1 Inserts for Page 3.8-34

Battery Gell-Parameters 3.8.6 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.6.2 Verify batteyr.col pa.am.oto.. moo.t Table 3.8.6 1 Category B limis 92 days AND

'GGew:thin 21 hours2.430556e-4 days 0.00583 hours 3.472222e-5 weeks 7.9905e-6 months afe-a bttefyL di*charge - 110 I for vital battories (11 3.5 V for vital battery V) or 106.5 V for 1DG ratte4ues AND Once mithin :24 hours overcharge ~150 V fopr i~tal battore battery V) or 115 V SR 3.8.6.3 Verify average eloctroTte temperature of 92 days representative cells is Ž 60 OF for vital batteries and 50°F for the PG battries.j

[Replace Surveillance Requirements with Insert 2 (TS 3.8.6 SRs).1 Watts Bar-Unit 1 3.8-35

Battery GeU-Parameters 3.8.6 Insert 2 - TS 3.8.6 SRs 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 volta-ge 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 and DG battery pilot cell 31 days float voltage is > 2.07 V.

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

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

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

Watts Bar-Unit I Inserts for Page 3.8-35

Battery Gell-Parameters 3.8.6 SURVEILLANCE FREQUENCY SR 3.8.6.7 ------------------------- NOTE ----------------

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

Verify battery capacity is > 80% of the manufacturer's 60 months rating when subiected to a performance discharge test or a modified performance discharge test. 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 Watts Bar-Unit 1 Inserts for Page 3.8-35

Battery Ge*l-Parameters 3.8.6 Table 3.8.6 1 (page 1 of !)

Ri*ttARv C'II PDammetr Req*I iriments CAT-EORY A_: CATEGORY B: CATEGOR PARAME LIMITS FOR EACH LIMITS FOR EACH ALLOWABLE LMIT DESIGNATED PILOT CONNE*T-ED CELL FR--*A Gr-09G#01eI4e Level M*irnmum leI iiu ee Above top of plates, indication mark, and indicatien mark, and and not ove.flowing

q41/ inc-abo- *1/4 inch aboe'-

maximum lelmaximum level4 indicatioRnmark (a) indication mark (a)

Fleat Veltage _2-.-.2..V

.>2.074 Specific Gravity (b)(c) -1.200 1.1-95 hnet mror than 0.0:20 beloW average of all AND connected coi Ave~age of al AND connected cells Average of agW connected cells (a) It it aceptable f4or the 9electrole level to tempo*rarly increase above the specified maxI mIm level during equalizing charges provided it is not evwflowing.

(b) Corrected far electrolyte temperature and level. Level correction is not required, however, when batter; charging 6 e-2 amps when on float charge for Vital batteries, and- -4 1..0 amp for DG batteres.

(G)

& I A batter: chargingI current of e-2 amps when on float charae for vital batteries6 -and- 41.0 amoR for DG batterfies is acceptable for mneeting specific gravity limits. followineg a batter,' recharge, for a maximum of 31 days. When charging current is used to satisfy specific graVity requir~ements, sPeecifi Eravitv o~f eac-rh connectedl cell shall be measrG'ed Drierr ....

to expiratien

. r ...............

of the 31 dav aiiewa4efRf Watts Bar-Unit I 3.8-36

Procedures, Programs and Manuals 5.7 5.7 Procedures, Programs, and Manuals 5.7.2.21 Battery Monitoring and Maintenance Pro-gram This Pro-gram 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 < 2.13V;

2. Actions to determine whether the float voltage of the remaining battery cells is - 2.13V when the float voltage of a battery cell has been found to be < 2.13V:

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 dischar-ge test, consistent with manufacturer recommendations.

Watts Bar-Unit 1 5.0-25b

ATTACHMENT 2 Proposed WBN Unit I Bases Page Changes (Markup)

(For Information Only)

A2-1

DC Sources-Operating B 3.8.4 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.4 DC Sources - Operating BASES BACKGROUND The station DC electrical power system provides the AC emergency power system with control power. It also provides both motive and control power to selected safety related equipment and preferred AC vital bus power (via inverters). As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1), the DC electrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a single failure. The DC electrical power system also conforms to the recommendations of Regulatory Guide 1.6 (Ref. 2) and IEEE-308 (Ref. 3).

125V Vital DC Electrical Power Subsystem The vital 125V DC electrical power system is a Class IE system whose safety function is to provide control power for engineered safety features equipment, emergency lighting, vital inverters, and other safety-related DC powered equipment for the entire unit. The system capacity is sufficient to supply these loads and any connected nonsafety loads during normal operation and to permit safe shutdown and isolation of the reactor for the "loss of all AC power" condition. The system is designed to perform its safety function subject to a single failure.

The 125V DC vital power system is composed of the four redundant channels (Channels I and III are associated with Train A and Channels II and IV are associated with Train B) and consists of four lead-acid-calcium batteries, eight battery chargers (including two pairs of spare chargers), four distribution boards, battery racks, and the required cabling, instrumentation and protective features.

Each channel is electrically and physically independent from the equipment of all other channels so that a single failure in one channel will not cause a failure in another channel. Each channel consists of a battery charger which supplies normal DC power, a battery for emergency DC power, and a battery board which facilitates load grouping and provides circuit protection. These four channels are used to provide emergency power to the 120V AC vital power system which furnishes control power to the reactor protection system. No automatic connections are used between the four redundant channels.

Battery boards 1,11, 111, and IV have a charger normally connected to them and also have manual access to a spare (backup) charger for use upon loss of the normal charger.

(continued)

Watts Bar-Unit 1 B 3.8-54 Revision 105

DC Sources-Operating B 3.8.4 BASES BACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Additionally, battery boards I, II, Ill, and IV have manual access to the fifth vital battery system. The fifth 125V DC Vital Battery System is intended to serve as a replacement for any one of the four.125V DC vital batteries during their testing, maintenance, and outages with no loss of system reliability under any mode of operation.

Each of the vital DC electrical power subsystems provide the control power for its associated Class 1E AC power load group, 6.9 kV switchgear, and 480V load centers. The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, they power the emergency DC lighting system.

The vital DC power distribution system is described in more detail in Bases for LCO 3.8.9, "Distribution System - Operating," and LCO 3.8.10, "Distribution Systems - Shutdown."

Each vital battery has adequate storage capacity to carry the required load continuously for at least 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months in the event of a loss of all AC power (station blackout) without an accident or for 30 minutes with an accident considering a single failure. Load shedding of non-required loads will be performed to achieve the required coping duration for station blackout conditions.

Each 125V DC vital battery is separately housed in a ventilated room apart from its charger and distribution centers, except for Vital Battery V. Each subsystem is located 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 between redundant Class 1 E subsystems, such as batteries, battery chargers, or distribution panels.

The batteries for the vital DC electrical power subsystems are sized to produce required capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the 100% design demand. The voltage limit is 2.13 V per cell, whiGh correspends to a total minimum voltage output of ! 29V por batteFry (1232 for Vital Batter; V). The criteria for sizing large lead storage batteries are defined in IEEE-485 (Ref.5).

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum output voltage is 120V, for a 60 cell battery (vital battery) the total minimum output voltage is 124V and for a 62 cell battery (5 tI vital battery) the total minimum output voltage is 128V. The open circuit voltage is the voltage maintained when there is no charging or discharging. Once fully charged the battery cell will maintain approximately 97% of its capacity for 30 days without further charginq per manufacturer's instructions. Optimal long term performance however, is obtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This provides adeguate over-potential, which limits the formation of lead sulfate and self discharge.

(continued)

Watts Bar-Unit 1 B 3.8-55

DC Sources-Operating B 3.8.4 BASES BACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Each Vital DC electrical power subsystem has ample power output capacity for the steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged. Each battery charger also has sufficient capacity to restore the battery bank from the design minimum charge to its fully charged state within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (with accident loads being supplied) following a 30 minute AC power outage and in approximately 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (while supplying normal steady state loads following a 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months AC power outage), (Ref.6).

The battery charger is normally 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. This assures the internal losses of a battery are overcome and the battery is maintained in a fully charged state.

When desired, the charger can be placed in the equalize mode. The equalize mode is at a higher voltage than the float mode and charging current is correspondingly higher. The battery charger is operated in the equalize mode after a battery discharge or for routine maintenance. Following a battery discharge, the battery recharge characteristic accepts current at the current limit of the battery charger (if the discharge was significant, e.g., following a battery service test) until the battery terminal voltage approaches the charger voltage setpoint. Charging current then reduces exponentially during the remainder of the rechar-ge cycle. Lead calcium batteries have recharge efficiencies of greater than 91%, so once at least 110% of the ampere-hours discharged have been returned, the battery capacity would be restored to the same condition as it was prior to the discharge. This can be monitored by direct observation of the exponentially decaying charging current or by evaluating the amp-hours discharged from the battery and amp-hours returned to the battery.

125V Diesel Generator (DG) DC Electrical Power Subsystem Control power for the DGs is provided by five DG battery systems, one per DG.

Each system is comprised of a battery, a dual battery charger assembly, distribution center, cabling, and cable ways. The DG 125V DC control power and field-flash circuits have power supplied from their respective 125V distribution panel. The normal supply of DC current is from the associated charger. The battery provides control and field-flash power when the charger is unavailable.

The charger supplies the normal DC loads, maintains the battery in a fully charged condition, and recharges (480V AC available) the battery while supplying the required loads regardless of the status of the unit. The batteries are physically and electrically independent. The battery has sufficient capacity when fully charged to supply required loads for a minimum of 30 minutes following a loss of normal power. Each battery is normally required to supply loads during the time interval between loss of normal feed to its charger and the receipt of emergency power to the charger from its respective DG.

(continued)

Watts Bar-Unit 1 B 3.8-56 Revis ion 113

DC Sources-Operating B 3.8.4 BASES APPLICABLE The initial conditions of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in FSAR, Section 6 (Ref. 7), and in FSAR, Section 15 (Ref. 7),

assume that the Engineered Safety Feature (ESF) systems are OPERABLE.

The vital DC electrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all power for the emergency auxiliaries, and control and switching during all MODES of operation. The DG battery systems provide DC power for the DGs.

The OPERABILITY of the DC sources is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the plant. This includes maintaining the DC sources OPERABLE during accident conditions in the event of:

a. An assumed loss of all offsite AC power or all onsite AC power; and

b. A worst case single failure.

The DC sources satisfy Criterion 3 of the NRC Policy Statement.

LCO Four 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 supplying power to the associated DC bus within the channel; and four DG DC electrical power subsystems each consisting of a battery, a dual battery charger assembly, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (AOO) or a postulated DBA. Loss of any DC electrical power subsystem does not prevent the minimum safety function from being performed (Ref. 4).

An OPERABLE vital DC electrical power subsystem requires all required batteries and respective chargers to be operating and connected to the associated DC buses.

The LCO is modified by twefour Notes. Note 1 indicates that Vital Battery V may be substituted for any of the required vital batteries. However, the fifth battery cannot be declared OPERABLE until it is connected electrically in place of another battery and it has satisfied applicable Surveillance Requirements. Note 2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital charqers. Note 3 indicate that spare DG chargers 1Al, 1B1, 2A1, or 2B1 may be substituted for required DG chargers. However, the spare charger(s) cannot be declared OPERABLE until it is connected electrically in place of another charger, and it has satisfied applicable Surveillance Requirements. Note 24 has boon addod toindicates that the C-S DG and its associated DC subsystem may be substituted for any of the required DGs.

However, the C-S DG and its associated DC subsystem cannot be declared OPERABLE until it is connected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.

(continued)

Watts Bar-Unit 1 B 3.8-57 Revision 113

DC Sources-Operating B 3.8.4 BASES APPLICABILITY The four vital DC electrical power sources and four DG DC electrical power sources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safe plant operation and to ensure that:

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AOs or abnormal transients; and

b. Adequate core cooling is provided, and containment integrity and other vital functions are maintained in the event of a postulated DBA.

The DC electrical power requirements for MODES 5 and 6 are addressed in the Bases for LCO 3.8.5, "DC Sources - Shutdown."

ACTIONS A.1. A.2. A.3. E.. E.2. and E.3 Condition A. represents oe vital ch annol with a loss of ability toomepletely respond to an event, and a poteRti* 4loss of ability to emi en .ergzdduring normai operation. it Is, tleretoe, imperative tnat t1*e peraltorsI1 at tRention*I* ou*Ro stabilizing the plant, minimizing the potential for complete loss . of DC power to the affecoted- trainR. The 2 hulismit isconsistent With the alloweAAd_ timoP for an inoperable DG distribution system train.

If one of the required vital DG olectrical powor subsystems is,inoporable (e.g.,

inoperable batter,', inoporable batter; charger(s), or inoperable battor; chargor and associated ioRporablo bailer,'), the remaining vital DG electrical poere subsystem has the capacity to suppedt a.cafe s11-hutdown and to m~itigate an accident conddition. SinoR~a subsequent worst case single failue of the OPE=RABLEm subsystem would, however, result in a sitution wfheerethe ability of the 125V DG electrical power subsystem to suppedt its required ESF function is not assurFed, continRued power operation should not excoed -2hourws. T-he 2hour Completion Time is based on Regulator,' Guide 1.93 (Ref. 8) and reflects _a reasonable time to assess plant status as a;func-tion of the inoperable vital PC electirical power subsystem and, if the vital DC electrical power subsystemA is not restore9d to-OPERABLE. status, to prepare to effect an orderly and safe plant sh, 4tawn~

(continued)

Watts Bar-Unit I B 3.8-58

DC Sources-Operating B 3.8.4 BASES A t'rI-*%kIC B.!-and- .2 if the inoperablo8 Vital DC oloctrical power 6ubeystom cannoRQt be rosto4hroRd_ to-OPERABLE status within the required Complotion Time, the plant Must he bFrught to a MODE, iR Which the LCO de*r not apply. To achieve this status, the-plant mAust be brog~lht to at least MODE 2 withnA 6 hourFS and to MODE 5 within 368 hours0.00426 days 0.102 hours 6.084656e-4 weeks 1.40024e-4 months . TPhe allowMAed Completion Times are reasonable, based an operatingf experience, to reach the required plant conditions frmF full power conditions ina4rl orderly mnanner and without challenging plant systems. The Completion Timne to bring the plant to MODE 5 is6Gconstent with the tiMe Feqw÷,ed in Regulator; Guide 1.*3 (Ref. 8).

G_4 Condition G represents oneDG with a lss oef ability to chmpletely rosperad to a eveNt. Srinde a subrequet rsingle failue On the o ppoesite train coetd result in a atationawhere the requ E ired cS is not assured, eontirued power function opefation shouldwi t eXieed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The t 2 hous rintheisnsenwith fimeWAelim the allowed time foPR an inoperable vital DG electrical power subsystemr.

94 If the DG Dr electrical power subsystem cannot be restored to OPERAbBLE sotatus in the associated Completier Time, the atssoeated Dh may beinapable of peminmimg its intended functivo be iAmeduately declared inorl and muvistd This declaratiero awls requires entry inteapplicable conditions and Required Actions for a inopr D, LCO 3.8.1, "AC Souresb Operatint."

Condition A and E represent one channel with one battery charg-er inoperable (e.g.. the voltage limit of SR 3.8.4.1 or SR 3.8.4.2 is not maintained). The 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 reasonable time period. Required Actions A.1 and E.1 require that the battery terminal voltage be restored to greater than or egual to the minimum established float voltagqe within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . This time provides for returning the inoperable charger to OPERABLE status or providing an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float.

voltage. Restoring the battery terminal voltage to greater than or eglual to the minimum established float voltage provides good assurance that, within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , the battery will be restored to its recharged condition from any discharge that might have occurred due to the charger inoperability.

A discharged battery having terminal voltage of at least the minimum established float voltage indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. The time to return a battery to its fully charged state under this condition is simply a function of the amount of the previous discharge and the recharge characteristic of the battery. Thus there is good assurance of fully recharging the battery within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , avoiding a premature shutdown with its own attendant risk.

If battery terminal float voltage cannot be restored to greater than or equal to the (continued)

Watts Bar-Unit 1 B 3.8-59

DC Sources-Operating B 3.8.4 BASES minimum established float voltage within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , and the charger is not operating in the current-limiting mode, a faulty charger is indicated. A faulty charger that is incapable of maintaining established battery terminal float voltaaqe does not provide assurance that it can revert to and operate properly in the current limit mode that is necessary during the recovery period following a battery discharge event that the DC system is designed for.

If the charger is operating in the current limit mode after 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months that is an indication that the battery is partially discharged and its capacity margins will be reduced. The time to return the battery to its fully charged condition in this case is a function of the battery charger capacity, the amount of loads on the associated DC system, the amount of the previous discharge, and the recharge characteristic of the battery. The charne time can be extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Required Actions A.2 and E.2 require that the battery float current be verified less than or equal to 2 amps for the vital battery and less than or equal to 1 amp for the DG battery. This indicates that, if the battery had been discharged as the result of the inoperable battery charger, it is now fully capable of supplying the maximum expected load reduirement. The 2 amp value for the vital battery and the 1 amp value for the DG battery are based on returning the battery to 98%

charge and assume a 2% design margin for the battery. If at the expiration of the initial 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months period the battery float current is not less than or equal to 2 amps for the vital battery or 1 amp for the DG battery, then this indicates there may be additional battery problems and the battery must be declared inoperable.

Required Actions A.3 and E.3 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., balance of plant non-Class 1E battery charger). The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time reflects a reasonable time to effect restoration of the qualified battery charger to OPERABLE status.

B.1 and F.1 Conditions B and F represent one channel (subsystem) with one battery inoperable. With one battery inoperable, the DC bus is being supplied by the OPERABLE battery charger. Any event that results in a loss of the AC bus supporting the battery charger will also result in loss of DC to that subsystem.

Recovery of the AC bus, especially if it is due to a loss of offsite power, will be hampered by the fact that many of the components necessary for the recovery (e.g., diesel generator control and field flash circuits, AC load shed and diesel generator output circuit breakers, etc.) will likely rely upon the battery. In addition any DC load transients that are beyond the capability of the battery charger and normally require the assistance of the battery will not be able to be brought online. The 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months limit allows sufficient time to effect restoration of an inoperable battery given that the maiority of the conditions that lead to battery inoperability (e.g., loss of battery charger, battery cell voltage less than 2.07 V, etc.) are identified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specific Completion Times.

Watts Bar-Unit 1 B 3.8-59a

DC Sources-Operating B 3.8.4 BASES C.1 and G.1 Conditions C and G represent a loss of one DC electrical power subsystem to completely respond to an event, and a potential loss of ability to remain energized during normal operation. It is therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete loss of DC power to the affected subsystem. The 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months limit is consistent with the allowed time for an inoperable DC distribution subsystem.

If one of the required DC electrical power subsystems is inoperable for reasons other than Conditions A or B for the vital batteries or Conditions E or F for the DG DC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accident condition. Since a subsequent worst case single failure could, however, result in the loss of the minimum necessary DC electrical subsystems to mitigate a worst case accident, continued power operation should not exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months Completion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects a reasonable time to assess unit status as a function of the inoperable DC electrical power subsystem and, if the DC electrical power subsystem is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown.

D.1 and D.2 If the inoperable Vital DC electrical power subsystem cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. The Completion Time to bring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).

9H.1 If the DG DC electrical power subsystem cannot be restored to OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must be immediately declared inoperable.

This declaration also requires entry into applicable Conditions and Required Actions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."

Watts Bar-Unit 1 B 3.8-59b

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2 REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the battery charners, which support Ghafg#fi-eystem-af,d-the ability of the batteries to perform their intended function. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state while supplying the continuous steady state loads of the associated DC subsystem. On float charge, battery cells will receive adequate current to optimally charge the battery. The 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. For example the minimum nominal terminal voltage for the 5th Vital Battery is 136V (62 cells times 2.20 Vpc), the minimum nominal terminal voltage for the vital batteries is 132V (60 cells times 2.20 Vpc) and the minimum nominal terminal voltage for the DG batteries is 128V (58 cells times 2.20 Vpc).

These voltaqe levels maintain the battery plates in a condition that supports maintaining the grid life.

The voltage requirements listed above are based on the critical design voltage of the battery and are consistent with the initial voltages assumed in the battery sizing calculations. The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).

SR 3.8.4.3 Verifying that for the vital batteries that the alternate feeder breakers to each required battery charger is open ensures that independence between the power trains is maintained. The 7-day Frequency is based on engineering judgment, is consistent with procedural controls governing breaker operation, and ensures correct breaker position.

SR 3.8.4.4 This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning properly, with all required circuit breakers closed and buses energized from normal power. The 7 day Frequency takes into account the redundant DG capability and other indications available in the control room that will alert the operator to system malfunctions.

SR 3.8.4.5 and SR 3.8.4.6 Visual inspoc.tio. toe U9 dotct corro.ion of the battey coIs and connections, or moeasUr8Fem t of the rosistance of oach ineclitrak nooanda tor-minal connucu:n, pr1y.laec aRn indcic=tn Of pnyscI= damage OFraonormna Eoe!rioraiu-on that could potentially dograd, battery pe.foermance. These SRs verify the design capacity of the vital and DG battery chargers. According to Regulatory Guide 1.32 (Ref. 6). the battery charger supply is recommended to be based on the largest combined demands of the various steady state loads and the charging capacity to restore the battery from the design minimum charge state to the recharged state, irrespective of the status of the unit during these demand occurrences. Verifying the capability of the charger to operate in a sustained current limit condition ensures that these requirements can be satisfied.

(continued)

Watts Bar-Unit 1 B 3.8-60

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.5 and SR 3.8.4.6 (continued)

REQUIREMENTS The limits, established for thiS SR must be no more8 than 20% abovo the resistanco as mneasured during installation, or not above the cefiling value established by the manufacturer. The SRs provide two options. One option requires that each vital battery charger be capable of supplying 200 amps (20 amps for the DG battery charger) at the minimum established float voltage for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . Recharging the battery or testing for a minimum of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months is sufficient to verify the output capability of the charger can be sustained, that current limit adjustments are Properly set and that protective devices will not inhibit performance at current limit settings.

The Sr'ilac FrFequencY foar these inspection, Which can detect conditions that can cause poWer losses due to Ire-sistancue heating, is,92 days. This Frequency is conrsidred acceptable based n opaerating expefienre related to detecting corrosion trends.

rhe other option requires that each battery changer be caroable of recharging the battery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the status of the plant during which these demands occur). This level of loading may not normally be available following the battery service test and will need to be supplemented with additional loads. The duration for this test may be longer than the charger sizing criteria since the battery recharge is affected by float voltage, temperature, and the exponential decay in charging current. The battery is recharged when the measured charging current is < 2 amps for the vital batteries and < 1 for the DG batteries.

The Surveillance Frequency is acceptable, given the plant conditions required to perform the test and the other administrative controls existing to ensure adequate charger performance during these 18 month intervals. In addition, this Frequency is intended to be consistent with expected fuel cycle lengths.

(continued)

Watts Bar-Unit 1 B 3.8-61 Revision 56, 69 Amendment 54

DC Sources-Operating B 3.8.4 BASES SR 3.8.4.7 Visual inspec~tionA of the-batter,' cells, cel! plates, and batter' rackrs provides, an in;dication of phy*-i*l damage or abnormal deterioration that could potentially degrade batter. pe1formancI.*,

The 12 mRonth Frequency for this SR is consistent With IEE 1~=450 (Ref. 9), Which recommendr, detailed visual insiqecti9n of coi cnd-ition and racRk intearity on a yea.basis.A battery service test is a special test of battery capability, as found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system. The discharge rate and test length should correspond to worst case design duty cycle requirements based on References 10 and 12.

The Surveillance Frequency of 18 months is consistent with the recommendations of Regulatory Guide 1.32 (Ref.6) and Regulatory Guide 1.129 (Ref. 11), which state that the battery service test should be performed during refueling operations or at some other outage, with intervals between tests, not to exceed 18 months.

This SR is modified by two Notes. Note 1 allows the performance of a modified performance discharge test in lieu of a service test. The modified performance discharge test is a simulated duty cycle consisting of must two rates; the one minute rate published for the battery or the lar-gest current load of the duty cycle, followed by the test rate employed for the performance test, both of which envelope the duty cycle of the service test. Since the ampere-hours removed by a rated one minute dischar-ge represents a very small portion of the battery capacity, the test rate can be changed to that for the performance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance dischar-ge test should remain above the minimum battery terminal voltage specified in the battery service test forthe duration of time equal to that of the service test.

Note 2 allow the plant to take credit for unplanned events that satisfy this SR.

Examples of unplanned events may include:

11 Unexpected operational events which cause the eguipment to perform the function specified by this Surveillance, for which adequate documentation of the required performance is available; and 2.) Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component to OPERABLE, provided the maintenance was required, or performed in coniunction with maintenance required to maintain OPERABILITY or reliability.

Watts Bar-Unit 1 B 3.8-61 a

DC Sources-Operating B 3.8.4 BASES SR 3.8.4.8. SIR. 3.8.41.9-aind SR 3.8.1.10 Visual inspection and resistance measuremonts of ntrac nede, intrcl, 8 and-terminall connectfions provide an indication Of physical damage or abnormal deterioration that could indicate degraded batter; condition. The anticorrosion mnaterial is used to help ensure good 8eletricial connections and to reduce termin-al deterioration. The visual inspection for corrosionA is not inended to reqireremval of an~d inspection under eac-i-h termin-al cneto.The remoeval of voisibhle corrosio isa rentive mnaintenance SR. The presence of visible corrosion does not necessarily r-epresent a;failure of thisSRpoievsbl coroson s emoved duFrin pedoF~armanc of SR 3.8.1.8. For the purposes of trending, inter cell (vital and DG batteries) and inter tier (vital and DG baftteies) connecR6tionsG are measured from batter' post to batter; post. Inter rack (vital batteries), inter tier (DG Batteries), and terminal connec8tions (vital And DG batteries) are measure-d *fro terminal lug to battery post-.

Watts Bar-Unit 1 B 3.8-61 b

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.8. SR 3.8.4.9 and SR 3.8.1.10 (continued)

REQIRt* IISEMENTS The cnneRctin res;h L limits for SR 3.8.1.9 and SR 3.8.1.10 s;hall bo no mor-than 20%7 above the resistance as mneauroc curing instaiiamion, or not apeeve Mnc coiling value established by the manufacturer.

The Sur-me-illance rFrequencies of 12 months, is,consFistent;with IEEE 150 (Ref. 9),

which recommends cell to cell and terminal connection resistance measurement eR a yeagyba e This SR requires that each vital battery charger be capable of*e*harging its associated batter; from a capacity or sor~ice discharge test while supplying normal loads, Or alternatively, operating at cu*rRet Iimit for a minimumA of 1 houlrs at a nominal 1215 VDCG. These rq . irmnts are based en the design capacity of the chargrs (Ref. 4) and theiFr performanc charaGteristic of curre9nt Imfit operation for a substantial portion of the recharge period. Batter; charger output current oi,limited to 110% 125% of the 200 amp rated output. Reharfgirg the bailer' or testing for a minimum of 14or ssfiin to verify the output capability Of th chaFrger cncy besusained, that g-cuent limit adjustments are properly set and that protective devi*cs**Will not n*hibit pefor.ance at current limit settngs. According to Regulator,' Guide 1.32 (Ref. 6), the batter,' charg@er supply is requir~ed to be based en the largest combined demands of the various steady state leads and the charging capacity to restore the batter; from the design ini*mu mcharge state to the fully charged state, irrespective of the status of the plant during these dem,,and,occu..

÷*÷rrences. Verifying th8 capability of the charger to operate in a sustained courrent limit condition ensures that these requirements can be satisfied-.

The Surve"iance FrFequency is acceptable, given the plant conditions required to-pwerfor the test and the other administrative controls existing to ensure adequat charger performnance durinig these 189 month finter~vals. in addition, this FrFequency is inten-ded_ to bhe consistent With expected fuel cycle lengths.

(continued)

Watts Bar-Unit 1 B 3.8-62

DC Sources-Operating B 3.8.4 BASES S*1RVEII I ALNGlS"8'1 (continuod)

REQUIREMENTS This SR is medified by a Note. The roascn for the Note is that pe.forming the Sur.'eillanco May perturb the olectrical distribution system and challenge safety syrstms. Thor Su,,eMIlance is normally porform..d duri*n MOIDES 5 ad 6 SO.nc it would ro.uiro the G e'eGtr*c;al *o"We subsystom to b ,

Rnoperablo during po.formanc of the . test. HoweV.. , thi. Sur.eillan. e May be pe*formned on MODES 1, 2, 3, Or 4 proIided the Vital B÷atte , V ri substituted in accordance With LCO Note 1. Credit mnay be takenfo unplanned events that Gatwsf' this SR. Examples of unplanned events may

1) Unexpected operational events which cGause the equipment to performn the function specified by this SUrVeillaAce, 'For WhIch adequate docume*ntatiGn Of the* equired perf*orman e is available; a~d

2) Post

1. . .. ..* ...rrective

. * ... . maintenance

.~ ..... .4.. te.sting

, . . that

. . requires

. ." . . . performance

of H.; u;. emn.;; ; P*;,,e.,r ;;'. w;;";".:

p'evi-etmte manternare Wtas required, or pefoFrmed in conjunction with mRaintenaneruid t( maintain OPERBILI TY Or reliability.

-SR3.84.!2 T-his SR requires that each diesel generator battery charger be capable of rech~arging itro associated battery from a capacity Or GerV9Ge diScharge test while supplying normnal loads, Or altebatively, operating at current limit for a minimu*mn of 411"2 hos at a nominal *125 D*. This requirement irs based On the design capacity Of the chargers (Ref. 13) and their perfoFrmance character istic. Of current limnit p*eration for a substantial po*rFtn of the recharge peieod. Batterl;l-har output current is limited to aiaiu f 14'007 of the 20aprtdOutpu.

Recharging the batter; verifies the outpu1t capability of th hagra e-sustained, that current limit adjustments are properly set and that protective devices well not inhibit per9forance at current limit settings. AccorFding to Regulator,' Guide 1.32 (Ref. 65), the battery .charger supply is,required to be based on the largest combined demands of the various steady state loads and the charging capacity to restoeM the battery from the desg minmu :harge c state to the fullycharged state, irrFespective of the status,of the plant during these demand occurrences. Verifying the capability of the charger to operate in a suIstained current limfit GGondition; ensures that these requirements can be 6atmfiefld.

(continued)

Watts Bar-Unit 1 B 3.8-63 Revision 112

DC Sources-Operating B 3.8.4 BASES SUIDRVEIILLA.NCEIGi= SR 3.8.4412(ctnud REQlIREENlTS; The Sur.'eillance FrFequency is acceptable, given the plant conditions required to performA the test and thes other administrative controls existing to ensure adequate charge*r peFr4frmanle during these 18 month interals. In addition, this FrFequency is intended to be consistent With expected fuel cycle lengths.

.Fo subsystem, this Su.ei the DG DG electrical may be performed MODES 1,2, 3, or 4 in conjunctio With LCO 3.8.1 .B since the DGZ Q electrical power Gubcy~tomR supplies leads only for the inoper~able diesel gener-ator and would net otheWrxs challenge safety systems supplied from vital electrical distr&ibution systems. if available, tfhe G , UG and its assoc.iated PC eir" tc*,-a power subsystem . .acsubstituted in may be LO

.rdan.e. .ith Note 2.

Additionally, credit may be taken for unplanned events that satisfy+this, SR Examp!es of unplanned events may inc'lude:

1) Unexpected operational events which cause the equipment to performR the function specified by this Surveillance, for which adequate-documnentation of the required performnance is available; and

2) Pest cor-rec~tive maintenance testing that requires perfoFrmance of this, Survillnce n oder to restore the component to OPERA.BLE, provided the maintenance was required, or performned in conjunction wMith

.main;tenance required to maintain OPERABILITY or relfiability A bailer; ser~ice test is a special test of batter; capability, as found, to satisfy th deswRg FequFie*ment* (battery' duty cycl,) Of the DG eletFri*al power system,. The, discharge rate and test length should correspond to wonrst case design dluty cycl requirements based On Reference.0 and 12.

The Surveillance rFrequency of 18 mo~nths is consistent with the recommendations of Regulator; Guide 1.32 (Ref. 6) and Regulator; Guide 1.129-(Ref. 11), which state that the batter,' service test should be perfoFrmed during.

refueling operations, Or at some other outage, with intervals between tests, net to-exceed 18 mon~ths.

(continued)

Waits Bar-Unit 1 B 3.8-64 Revision 19, 66 Amendment 12

DC Sources-Operating B 3.8.4 BASES SURVEILLA.hCE SR3..11 (continued)

REQUIREMENTS T-his SR is moedified by two Notes. Noto I allows tho performFance of a modified performnance discharge test in lieu of a servic~e test once per 60 mon~ths. The moedified performance discharge test is a simulatod duty cycle consisting of just two rates; the one minute rate published for the batter,' Or the largest current load of the duty cycle, followed by the test rate employed for the perforancwe test, bonth of %whic-henvelope the duty cycle of the ser~ice testf. SiOnce the am~pere hours6 removed by a rated one minute discharge represents a vory'small portion of the battory capacity, tho test rate can be changed to th-at for the performFance teswithout copoiig the results of the performFance discharge test.

The bailer; termin~al voltage for the moedified porfoFrmance discharge test should-remai~n above the Fminim;um bailery teFrminal voltage specified in the bailer,'

s;ervicne test foAr the dluration of time equal to that of the serVice test.r A moedified discharge test is a test of the bailer,' capacity and its ability to provide a high rate, short duration load (usually the highest rate of the du~ty cycle.) This, Will Gften confir the bailers ability to moo.t the c...ti.al period 01 the lead duty cycle, in addition to deteMrminin its percentage Of rated capacity. Initial:

conditions for the moedified performance discharge test should be identicall to those specified for a ser:ice test.

Theuron ,,+for Note 2 is that performin*g the Sur illance .. may prturb the Vital e~lecrtric~al dis-tribution systemn and- challenge safety systemsR. How8eve, this Suryeillance may be performed inMODES I, 2, 3, Or 4 provided that Vital Bailer;L Vsusten accordance wiNot 2. dtC0nIA-, e 1. Foyr the OG QC elnctrical ubs.ystems, this sur-i..ancmay be performed in MODES , 2, 3, or 4 in cejntinwt LCO 3.8.l.B since the supplied loads are only for the inoeal dislgeeao and would not othorwffise challenge safety system leas; wAhic-h are supplied fromR vital electrical distribution systemsr. if available, the C S DG and its associated DG electrical power subsystemA may be substituted in accordance With LCO Note 2. Additionally, credit mnay be taken for unplanned events that satisb' this SR. Examples of unplanned events mnay icue

1) Unexpected operation-al e-venIts which cause the equipment to performA i dl I Ill F I i i he8umntiAonspecifiedbv thi6 Surveiiiance .......... 7 ror ........ ui Iaaeouate

...

Wnic docum~entation of the roqui're penr,,anco s available; -and

.-- j * .-- --i (continued)

Wafts Bar-Unit 1 B 3.8-65 Revision 12 Amendment 12

DC Sources-Operating B 3.8.4 BASES SUVI\rll ANCE'r SR 3.8.1.13 (contnuod),,rl REQUIREMENTS

2) Poet corecF8tivo maintonance totting that roquires perform~anco Of this Sur.'eilance in orFder to restore the component to OPERABLE, provided the mnaintenance Was, required, Or perfoFrmed in conjunction with mnaintenance required to mnaintain OPERABILITY or reliability.

SR-3.9.4.44 A bailer,' performance discharge test is, a test of.cnwstant current capacity of a bailer,', normna ly done in tho as found conditio, aftor having boon in ser~ice, to-detect any change in the csapacity deteFrmined by the acceptance test. The test is_

intended to determnine overall bailer,' degradation due to age and usage.

A bailer, modified perform~ance discharge test is describeAd_ in the- B~ases for 32.8.1.123. Eithe the batter,'perforaEn;e diechargo test Or the modified perfoqrmance discharge testis6 acceptable foFrsatisfYing SR 3.8.4f1.; however, only the modified per*forancs e discharge test May be used to satisfy SR 3.5.1.11 while satisfying the requiremfents of SR 3.8.1.13 at the same time.

The acceptanceh*

crteria; for this Su, are cRonsistent with IErEE=

,feillane 450 (Ref. 9) and IEEE 15 (Ref. 5). Thhese references d rco.meAd that the balefr, be replaced if its capacity is,belo)w 80% of the-manuf.act'urer rating. A capacity of 80% chews that the bailer,' rate of deterioratio i ncesRg even if there is ample ca~iacity to mneet the load requirem~ents.

The Sur.'eilance Frequency for this test is normnally 6_0 months. If the bailer,'

shows degradation, or if the bailer,' has reached 85% of its expecated life and capacity is 100% o~f the m~anufacturer's rating, the Suryeillance Freuec ' Is reu edt 1_2 months. H'A; A"owever, if the baile~yrshows no degradation but hams reachedd 8-5%. of its expected life, the Suw.eillance FrFequency is only reduced to

21. moen~ths foA-r bhafAFierie that retain capacity :! 100% o-f the mnanufac;ture~rs rating.

Degradation is Ondic~ated, according to IEEE 150 (Ref.f 0), when the bailer capacity drops by mor9e than 10% relative to its capacity on the preiu performnance test or wMhen it is > 10%5 belowA the MAnu facturer rating. These FFreuencies are c~~wonitent with the recommFn~endations fin IEEE 150 (Ref.91t (continued)

Waits Bar-Unit 1 B 3.8-66 Revision 19 Amendment 12

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.14 (continued),

DrEQU*lI REM EN5AI:

TS This SR is modified by a Note. The reason for the Note is that pefeorming the Surveillance may pedurb the vital electrical distFibution system and challenge safety systems. However, this Sun'eillance mnay be performed in MODES 1,2, 3-,

or 4 provided that Vital Battery' V is substituted in accordance with LCO Note I.

For the DG DC electrical subsystem, this suM"eillance may be performed in MODES I, 2, 3, Or 4 in conjuncfion With LCO 3.8.l.B since the supplied leads are only fr the inoperable diesel generator would net etherise challenge safety

,and system leads which are supplied frem vital electri;cia d;s*tibution systems. if avalable, the C S DG and isassociated DG electrial power subsystem may be substituted in accor~dance With LCO Note 2. Additionally, credit may be takenfr unplanned events, that satisfy this SR. Examples of unplanned events mnay

1) Unexpected operational events which cause the equipment to performn the-tunction. specitied by tihiG SeFV e aAGe, tor W..c.hadequate dGcum.e*tation of the required perforn ej an4

2) Post corrective mainte nance testing that requires performnance oft hie Survillncein order tiD restore the component to OPERABLE, pro v'-dtcd tne m~aintenance was required, Or performed in conjunction with-m~aintenance required to maintain OPERAB-ILITY or reliability.

(continued)

Wafts Bar-Unit 1 B 3.8-67 Revision 19 Amendment 12

DC Sources-Operating B 3.8.4 BASES REFERENCES 1. Title 10, Code of Federal Regulations, Part 50, Appendix A, General Design Criterion 17, "Electric Power System."

2. Regulatory Guide 1.6, "Independence Between Redundant Standby (Onsite) Power Sources and Between Their Distribution Systems," U.S.

Nuclear Regulatory Commission, March 10, 1971.

3. IEEE-308-1971, "IEEE Standard Criteria for Class 1E Power Systems for Nuclear Power Generating Stations," Institute of Electrical and Electronic Engineers.

4. Watts Bar FSAR, Section 8.3.2, "DC Power System."

5. IEEE-485-1983, "Recommended Practices for Sizing Large Lead Storage Batteries for Generating Stations and Substations," Institute of Electrical and Electronic Engineers.

6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric Power Systems for Nuclear Power Plants," February 1977, U.S. Nuclear Regulatory Commission.

7. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6 "Engineered Safety Features."

8. Regulatory Guide 1.93, "Availability of Electric Power Sources," U.S.

Nuclear Regulatory Commission, December 1974.

9 IEEE 150) 1980!11995, "IEFEE Rocommended Practice for MainteAnceG ToSting and Replacemnent of Largo Load Storage Battoriesfo Generating Stations and Subsystems," Institute of Elec8trical and Elec"Rnic Engineers.. IEEE-450-2002, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Vented Lead - Acid Batteries for Stationary Applications," Institute of Electrical and Electronics Engineers, Inc.

10. TV4A CGaIulation WBN EEB MS TIl-l 1-0003, "125 VDC Vital Batter' y an Charger Evalation.:" TVA Calculation EDQ00023620070003, "125V DC Vital Battern System Analysis."

11. Regulatory Guide 1.129, "Maintenance Testing and Replacement of Large Lead Storage Batteries for Generating Stations and Subsystems,"

U.S. Nuclear Regulatory Commission, February 1978.

(continued)

Watts Bar-Unit 1 B 3.8-68

DC Sources-Operating B 3.8.4 BASES REFERENCES 12. TVA Calculation WBN EEB-MS-TI 11-0062, "125 V DC Diesel Generator (continued) Control Power System Evaluation"

13. Watts Bar FSAR, Section 8.3.1, "AC Power System."

Watts Bar-Unit 1 B 3.8-69

DC Sources - Shutdown B 3.8.5 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.5 DC Sources - Shutdown BASES BACKGROUND A description of the DC sources is provided in the Bases for LCO 3.8.4, "DC Sources - Operating."

APPLICABLE The initial conditions of Design Basis Accident and transient analyses in SAFETY the FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume that Engineered ANALYSES Safety Feature systems are OPERABLE. The vital DC electrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation. The DG battery systems provide DC power for the DGs.

The OPERABILITY of the DC sources is consistent with the initial assumptions of the accident analyses and the requirements for the supported systems' OPERABILITY.

The OPERABILITY of the minimum DC electrical power sources during MODES 5 and 6, and during movement of irradiated fuel assemblies ensures that:

a. The plant can be maintained in the shutdown or refueling condition for extended periods;

b. Sufficient instrumentation and control capability is available for monitoring and maintaining the plant status; and

c. Adequate DC electrical power is provided to mitigate events postulated during shutdown, such as a fuel handling accident.

The DC sources satisfy Criterion 3 of the NRC Policy Statement.

(continued)

Watts Bar-Unit 1 B 3.8-70

DC Sources - Shutdown B 3.8.5 BASES (continued)

LCO 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 trains 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 train (i.e., Channels I and III, or II and IV) and two DG DC electrical power subsystems (i.e., 1A-A 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 LCO is modified by twefour Notes. Note 1 indicates that Vital Battery V may be substituted for any of the required vital batteries. However, the fifth battery cannot be declared OPERABLE until it is connected electrically in place of another battery and it has satisfied applicable Surveillance Requirements. Note 2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers. Note 3 indicates that spare DG chargers 1A1, 181, 2A1, or 2B1 may be substituted for required DG chargers. However, the spare charger(s) cannot be declared OPERABLE until it is connected electrically in place of another charger, and it has satisfied applicable Surveillance Requirements. Note 4 har beon added to indicates that the C-S DG and its associated DC subsystem may be substituted for any of the required DGs.

However, the C-S DG and its associated DC subsystem cannot be declared OPERABLE until it is connected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.

Applicability The DC electrical power sources required to be OPERABLE in MODES 5 and 6, and during movement of irradiated fuel assemblies, provide assurance that:

a. Required features needed to mitigate a fuel handling accident are available; (continued)

Watts Bar-Unit 1 B 3.8-71

DC Sources - Shutdown B 3.8.5 BASES APPLICABILITY b. Required features necessary to mitigate the effects of events that can (continued) lead to core damage during shutdown are available; and

c. Instrumentation and control capability is available for monitoring and maintaining the plant in a cold shutdown condition or refueling condition.

The DC electrical power requirements for MODES 1, 2, 3, and 4 are covered in LCO 3.8.4.

ACTIONS A.1, A.2.1, A.2.2, A.2.3, and A.2.4 If two trains are required by LCO 3.8.10, the remaining train with DC power available may be capable of supporting sufficient systems to allow continuation of CORE ALTERATIONS and fuel movement. By allowing the option to declare required features inoperable with the associated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with the affected required features LCO ACTIONS. In many instances, this option may involve undesired administrative efforts. Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies, and operations involving positive reactivity additions). The Required Action to suspend positive reactivity additions does not preclude actions to maintain or increase reactor vessel inventory, provided the required SDM is maintained.

Suspension of these activities shall not preclude completion of actions to establish a safe conservative condition. These actions minimize probability of the occurrence of postulated events. It is further required to immediately initiate action to restore the required vital DC electrical power subsystems and to continue this action until restoration is accomplished in order to provide the necessary DC electrical power to the plant safety systems.

(continued)

Watts Bar-Unit 1 B 3.8-72

DC Sources - Shutdown B 3.8.5 BASES ACTIONS A.1, A.2.1, A.2.2, A.2.3, and A.2.4 (continued)

The Completion Time of immediately is consistent with the required times for actions requiring prompt attention. The restoration of the required vital 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.

B. 1 If theone or more required DG DC electrical power subsystem cannot be restored to OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must be immediately declared inoperable. This declaration also requires entry into applicable Conditions and Required Actions for an inoperable DG, LCO 3.8.2, "AC Sources-Shutdown."

SURVEILLANCE SR 3.8.5.1 REQUIREMENTS SR 3.8.5.1 requires performance of all Surveillances required by SR 3.8.4.1 through SR 3.8.4.4-47. Therefore, see the corresponding Bases for LCO 3.8.4 for a discussion of each SR.

This SR is modified by a Note. The reason for the Note is to preclude requiring the OPERABLE DC sources from being discharged below their capability to provide the required power supply or otherwise rendered inoperable during the performance of SRs. It is the intent that these SRs must still be capable of being met, but actual performance is not required.

REFERENCES 1. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6, "Engineered Safety Features."

2. Watts Bar FSAR, Section 8.0, "Electric Power."

Watts Bar-Unit 1 B 3.8-73

Battery Geti-Parameters B 3.8.6 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.6 Battery Gell-Parameters I BASES BACKGROUND This LCO delineates the limits on battery float current, electrolyte temperature, electrolyte level, and cell float voltage, and sp1ci9c gr&vity for both the 125V vital DC electrical power subsystem and the diesel generator (DG) batteries. A discussion of these batteries and their OPERABILITY requirements is provided in the Bases for LCO 3.8.4, "DC Sources - Operating," and LCO 3.8.5, "DC Sources - Shutdown." Additional controls for various battery parameters are also provided in Specification 5.7.2.21, Battery Monitoring and Maintenance Program.

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts Per cell (Vpc). For a 58 cell battery (DG battery) the total minimum output voltage is 120V, for a 60 cell battery (vital batter) the total minimum output voltage is 124V and for a 62 cell battery (5th vital battery) the total minimum output voltage is 128V. The open circuit voltage is the voltage maintained when there is no charging or dischar-ging. Once fully charged the battery cell will maintain approximately 97% of its capacity for 30 days without further charging per manufacturer's instructions. Optimal long term performance however, is obtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This provides adequate over-potential, which limits the formation of lead sulfate and self discharge as discussed in FSAR, Chapter 8 (Ref. 4).

APPLICABLE The initial conditions of Design Basis Accident (DBA) and transient analyses in SAFETY the FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume Engineered Safety ANALYSES Feature systems are OPERABLE. The vital DC electrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation. The DG battery systems provide DC power for the DGs.

The OPERABILITY of the DC subsystems is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the plant. This includes maintaining at least one train of DC sources OPERABLE during accident conditions in the event of:

a. An assumed loss of all offsite AC power or all onsite AC power; and

b. A worst case single failure.

Battery eelI-parameters satisfy the Criterion 3 of the NRC Policy Statement.

I LCO Battery eel-parameters must remain within acceptable limits to ensure availability of the required DC power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence or a postulated DBA.

(continued)

Watts Bar-Unit 1 B 3.8-74

Battery Ge#-Parameters I B 3.8.6 BASES LCO EGt Batter parameter limits are conservatively established, allowing (continued) continued DC electrical system function even with Catogo.y A and B limits not met. Additional preventative maintenance, testing, and monitoring are conducted in accordance with Specification 5.7.2.21, Battery Monitoring and Maintenance Program.

APPLICABILITY The battery seel-parameters are required solely for the support of the associated vital DC and DG DC electrical power subsystems. Therefore, battery parameter limits are ele&9:I4e i6 only required when the DC power source is required to be OPERABLE. Refer to the Applicability discussion in Bases for LCO 3.8.4 and LCO 3.8.5.

ACTIONS A.1, A.2, an4-A.3, C.1, C.2, and C.3 With one Or mor9 cell6 in 9A9 Or mOre b".o Within limits (i.e., Category A-limits not met, Category B limits nRt me.t, or Catg-* ry A and B limit..nt Met) but-within the Categor; C limits specified in; Table 3.8.6 1 in the accomnpanyin _LCO, I the eator-y is dograded but mor~e is Still 6uRncIent capacity to ponormF~ tne_ Wended function9. Thoe~foe, the affocted batter; is not roquireAd_ to be consideredA~

2inoperable solely as a result of Categery A or B limit6 not mnet, and operation is pe~rmitted for a limited period-.

The pilot cell electrolyt level and float Voltage are requirod to be verified to mneet-the Category C lirmits within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months (Requirod Action Al). This*check will poide a quick iniainof the status of the remainder of the batter; cells. On hour provides time to inspect the electrolyte level and to confirmA the float voltage&

of the pilot coills. One hour is considered_ a Freaonable amou,nt of time to perfoDFrm the required ver-ification.

Verification that the Category G limi~ts are mnet (Required Action A.2) provides assurancGe that during the time needed to restore the parameters to the Category A and B3lfimits, the batter,' isstill capable of perfo9Frming its intended function. A period of 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is allowed to complete the initial Verification because specific gravity mneasurements must be obtained for each connected cell. Taking into consider-ation both the time required to performn the required Verification and the assurance that the batter' coil! paramneters are not seVerely deqraded, this ti~me is; con9sidered reasonable. The veiiainis reeated at 7 (continued)

Watts Bar-Unit 1 B 3.8-75

Battery Cell-Parameters B 3.8.6 BASES ACTIONS A.1, A.2, aP, -A.3, C.1, C.2, and C.3 (continued) day inter~als until the parameters are roetorod to Categor; A and B li*mits. Th486 poriodic verification ie consistent with the normal Frequency of pilot ceil Continued operation i6 erly permirted for 31 days before bastto, onel parameter muot boe rstored to WithirCategrr; A and B3limits. With the cosidveratio that, while battery degraded, sucot capacity iscaapacity misIto rio the internded fuction and to allow. time to.8.fully tofe the batte cell parameters ry to armeal limoit, this time is acceptable pcrqito declarnRg the batery inoperSable.

If one required vital battery or one required DG battery has one or more cell voltage <2.07 V. the battery is considered degraded. Within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months verification of the required battery charger OPERABILITY is made by monitoring the battery terminal voltage (SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state of charge by monitorinqthe batter float charge current (SRe3.8.6.1 or SR 3.8.6.12o This assures that there is still sufficient battery capacity to perform the intended function. Therefore, the affected battery is not required to be considered inoperable solely as a result of one or more cells in one battey < 2.07 V and continued operation is permitted for a limited period up to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

Since the Required Actions only specify "Perform," a failure of SIR 3.8.4.1. SIR 3.8.6.1, SIR 3.8.4.2. or SR 3.8.6.2 acceptance criteria does not result in this Required Action not met. However, if one of the SRs is failed the appropriate Condition(s) depending on the cause of the failures, is entered. If SIR 3.8.6.1 or.

SIR 3.8.6.2 is failed then there is net assurance that there is still sufficient batterv capacity to perform the intended function and the battery must be declared inoperable immediately.

B., B.2. D.1. and D.2 With oequ Or moa batteries with ona Or More battemp' cl parameters ouirtside the Category C limits for any coennected coil, sufficient capacity to supply the maximu.ml eAxpcted load requirement is not asrF;; ed and the corresponding Vital DG or DG DG electrical power subsystem must be declaredinprbe Additionally, other potentially extroeFA conditions, such as not completing the Required Ac-tions of Condition A within the required Completion Timeo vrg electrel4e temperature Of representatiVe cells falling below 60OF for the vital batteries Or 600F for DG_ batteries, are also cause forF immediately declamrig the assciaedVital DG Or _DG DG electrical power subsysteminpeabe One required vital battery with float current > 2 amps or one required DG battery with float current > 1 amp indicates that a partial discharge of the battery capacity has occurred. This 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. Within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months verification of the required battery charger OPERABILITY is made by monitoring the battery terminal voltage.

(continued)

Watts Bar-Unit 1 B 3.8-76

Battery -eII-Parameters B 3.8.6 BASES If the terminal voltage is found to be less than the minimum established float volta-ge there are two possibilities, the battery charqer is inoperable or is operating in the current limit mode. Condition A and C address charger inoperability. If the charger is operating in the current limit mode after 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months that is an indication that the battery has been substantially discharged and likely cannot perform its required design functions. The time to return the battery to its fully charged condition in this case is a function of the battery chargqer capacity, the amount of loads on the associated DC system, the amount of the previous discharge, and the recharge characteristic of the battery. The charge time can be extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (Required Actions B.2 and C.2). The battery must therefore be declared inoperable.

If the float voltage is found to be satisfactory but there are one or more battery cells with float voltage less than 2.07 V. the associated "OR" statement in Condition H is applicable and the battery must be declared inoperable immediately. If float voltage is satisfactory and there are no cells less than 2.07 V there is good assurance that, within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , the battery will be restored to its recharged condition (Required Actions B.2 and C.2) from any discharge that might have occurred due to a temporary loss of the battery charger.

A discharged battery with float voltage (the charger setpoint) across its terminals indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. The time to return a battery to its recharged state under this condition is simply a function of the amount of the previous discharge and the recharge characteristic of the battery. Thus there is good assurance of fully rechar-ging the battery within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , avoiding a premature shutdown with its own attendant risk.

If the condition is due to one or more cells in a low voltage condition but still greater than 2.07 V and float voltage is found to be satisfactory, this is not indication of a substantially discharged battery and 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is a reasonable time prior to declaring the battery inoperable.

Since Required Actions B.1 and C.1 only specify "perform," a failure of SR 3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in the Required Action not met.

However, if SR 3.8.4.1 or SR 3.8.4.2 is failed, the appropriate Condition(s),

depending on the cause of the failure, is entered.

E.1, E.2, and E.3 With one required vital or DG battery with one or more cells electrolyte level above the top of the plates, but below the minimum established design limits, the battery still retains sufficient capacity to perform the intended function. Therefore, the affected battery is not required to be considered inoperable solely as a result of electrolyte level not met. Within 31 days the minimum established design limits for electrolyte level must be re-established.

(continued)

Watts Bar-Unit 1 B 3.8-76a

Battery Gell-Parameters B 3.8.6 BASES With electrolyte level below the top of the plates there is a potential for dryout and plate degradation. Required Actions E.1 and E.2 addressed this potential as well as provisions in Specification 5.7.2.21 .b, Battery Monitoring and Maintenance Program. They are modified by a Note that indicates they are only applicable if electrolyte level is below the top of the plates. Within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months level is required to be restored to above the top of the plates. The Required Action E.2 requirement to verify that there is no leakage by visual inspection and the Specification 5.7.2.21 .b item to initiate action to equalize and test in accordance with manufacturer's recommendation are taken from IEEE Standard 450. They are performed following the restoration of the electrolyte level to above the top of the plates. Based on the results of the manufacturer's recommended testing the battery may have to be declared inoperable and the affected cell(s) replaced.

F. 1 With one required vital or DG battery with pilot cell temperature less than the minimum established design limits, 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months is allowed to restore the temperature to within limits. A low electrolyte temperature limits the current and power available. Since the battery is sized with margin, while battery capacity is degraded, sufficient capacity exists to perform the intended function and the affected battery is not required to be considered inoperable solely as a result of the pilot cell temperature not met.

G.1 With more than one required vital or more than one DG batteries with battery parameters not within limits as specified in Conditions A through F there is not sufficient assurance that battery capacity has not been affected to the degree that the batteries can still perform their required function, given that redundant batteries are involved. With redundant batteries involved this potential could result in a total loss of function on multiple systems that rely upon the batteries.

The longer Completion Times specified for battery parameters on non-redundant batteries not within limits are therefore not appropriate, and the parameters must be restored to within limits on at least one subsystem within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

H.1 With one or more batteries with any battery parameter outside the allowances of the Required Actions for Condition A. B. C, D. E, F or G sufficient capacity to supply the maximum expected load requirement is not assured and the corresponding battery must be declared inoperable. Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 V and float current greater than 2 amps for the vital batteries or 1 amp for the DG batteries indicates that the battery capacity may not be sufficient to perform the intended functions. Under these conditions, the battery must be declared inoperable immediately.

(continued)

Watts Bar-Unit 1 B 3.8-76b

Battery Getl-Parameters B 3.8.6 BASES SURVEILLANCE SR 3.8.6.1 and SR 3.8.6.2 REQUIREMENTS Thus SIR verifies; that Gategeoy A battory' oel! parame~toeF aro concictont with IEEE 450 (Ref. 2), Which rocomm~end6 regular battery' inspectionc (at least oee por monith) including voltage, specific gravity, and oloctrOlyte tem~porature Of pilot-Verifying battery float current while on float charge is used to determine the state of charge of the battery. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery and maintain the battery in a charged state. The equipment used to monitor float current must have the necessary accuracy and resolution to measure electrical currents in the expected range. The float current requirements are based on the float current indicative of a charged battery. The 7 day Frequency is consistent with IEEE-450 (Ref. 2).

This SR is modified by a Note that states the float current requirement is not required to be met when battery terminal voltage is less than the minimum established float voltage of SR 3.8.4.1 or SR 3.8.4.2. When this float voltage is not maintained the Required Actions of LCO 3.8.4 ACTION A or E are being taken, which provide the necessary and appropriate verifications of the battery condition. Furthermore, the float current limit of 2 amps for the vital battery and 1 amp for the DG battery is established based on the nominal float voltage value and is not directly applicable when this voltage is not maintained.

(continued)

Watts Bar-Unit 1 B 3.8-76c

Battery GeU-Parameters B 3.8.6 BASES SURVEILLANCE I REQUIREMENTS (continued) The qlurterly inspectio 9f specific gravity and voltage is consistont t 4D -A U +"k IEFEE 450 (Ref.2). in additi*on, within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of a batter; discharge 110V -

(11 3.5V forF Vital Batter,' V or-F 106.5P forF PG batterie6) or a batter; ovorchargo

>1 50V (15P -Vfor Vitalol Bailer; V Or 145VI for -DG-battor9ies), the batter; mnust be Ipn

...... ~ rat o ".k;.I, vnn~ptfrll a,. rMn 0. rao fa ~ +s ~ 4 4f'~ ~I (I ! 3.5V for Vital Batter; V or 106.5V for DG batteris), doa not constitute a battorp di'charge pro"ided the battery terminal voltage and float current return to pro tra-nsiet values. This ;nspe-ti-n is a6o9 consistent With !EEE 1-r-50 (Rf.2), whic recommeInds special inspections following a sovero dicharge

or erc*harqg, to oRo that no significant degradatiOn of the bailer- occurS

.. as.cnquence a Of such discharge Or oVer-harge.

SR-3.3a This Su'eillancq verification that the averago tempratue Of represenn toativ cellst isf 600F for the vital batteries, and 501F for vit the G batteriesI, is oansistnt 1wth a recommtendation of IheE 450 (Ref. 2), that states that the temperature Of potenales in representative clatils should be determnedse a quadterly basis.

';Lower than no~rmal temperatures act to inhibit or reduce batter; capacity. T-his SR eRnsure that the rS operating temiperatues Fremain within anaceptable operating range. This limipt ibarsed n manu fac recommendations5.7.2.21. SA s SR 3.8.6.3 and SR 3.8.6.6 Optimal long term battery performance is obtained by maintaining float voltage greater than or equal to the minimum established design limits Provided by the battery manufacturer which is 2.20 Vpc. This corresponds to a terminal voltage of 128V for the IDG batteries. 132V for the vital batteries I through IV and 136V for the vital battery V. The specified float voltage provides adequate over-potential, which limits the formation of lead sulfate and self discharge. which could eventually render the battery inoperable. Float voltages in this range or less, but greater than 2.07 Vpc. are addressed in Specification 5.7.2.21. SRs 3.8.6.3 and 3.8.6.6 require verification that the cell float voltages are equal to or greater than the short term absolute minimum voltage of 2.07V.

The Frequency for cell voltagqe verification every 31 days for pilot cell and 92 days for each connected cell is consistent with IEEE-450 (Ref. 2).

SR 3.8.6.4 The limit specified for electrolyte level ensures that the plates suffer no physical damage and maintains adequate electron transfer capability. The minimum design electrolyte level is the minimum level indication mark on the battery cell Dar. The Frequency is consistent with IEEE-450 (Ref.

2).

(continued)

Watts Bar-Unit 1 B 3.8-77

Battery Gel4-Parameters B 3.8.6 BASES SURVEILLANCE REQUIREMENTS (continued) SR 3.8.6.5 This Surveillance verifies that the pilot cell temperature is greater than or equal to the minimum established design limit (i.e., 60 °F for vital batteries and 50 OF for DG batteries). Pilot cell electrolyte temperature is maintained above this temperature to assure the battery can provide the required current and voltage to meet the design requirements. Temperature lower than assumed in battery sizinq calculations will not ensure battery capacity is sufficient to perform its design function. The Frequency is consistent with IEEE-450 (Ref. 2).

SR 3.8.6.7 A battery performance discharge test is a test of battery capacity using constant current. The test is intended to determine overall battery degradation due to age and usage.

Either the battery performance discharge test or the modified performance discharge test is acceptable for satisfyingq SR 3.8.6.7; however, only the modified performance discharge test may be used to satisfy the battery service test requirements of SR 3.8.4.7.

A modified performance test is a test of the battery capacity and its ability to provide a high rate, short duration load (usually the highest rate of the duty cycle). This will often confirm the battery's ability to meet the load duty cycle, in addition to determining its percentage of rated capacity. Initial conditions for the modified performance discharge test should be identical to those specified for a service test.

It may consist of must two rates; for instance the one minute rate for the battery or the largest current load of the duty cycle, followed by the test rate employed for the performance test, both of which envelope the duty cycle of the service test.

Since the ampere-hours removed by a one minute discharge represents a very small portion of the battery capacity, the test rate can be changed to that for the performance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge test must remain above the minimum battery terminal voltage specified in the battery service test for the duration of time equal to that of the service test.

The acceptance criteria for this Surveillance are consistent with IEEE-450 (Ref.

2) and IEEE-485 (Ref. 3). These references recommend that the battery be replaced if its capacity is below 80% of the manufacturer's rating. A capacity of 80% shows that the battery rate of deterioration is increasing, even if there is ample capacity to meet the load requirements. Furthermore, the battery is sized to meet the assumed duty cycle loads when the battery design capacity reaches this 80% limit.

(continued)

Watts Bar-Unit 1 B 3.8-77a

Battery Cl-U-Parameters B 3.8.6 BASES SURVEILLANCE SR 3.8.6.7 REQUIREMENTS (continued) The Surveillance Frequency for this test is normally 60 months. If the battery shows degradation, or if the battery has reached 85% of its expected life and capacity is < 100% of the manufacturer's ratinq, the Surveillance Frequency is reduced to 12 months. However, if the battery shows no degradation but has reached 85% of its expected life, the Surveillance Frequency is only reduced to 24 months for batteries that retain capacity > 100% of the manufacturer's ratingqs.

Degradation is indicated, according to IEEE-450 (Ref. 2), when the battery capacity drops by more than 10% relative to its capacity on the previous performance test or when it is > 10% below the manufacturer's rating. These Frequencies are consistent with the recommendations in IEEE-450 (Ref. 2).

This SR is modified by a Note. The reason for the Note is to allow the plant to take credit for unplanned events that satisfy this SR. Examples of unolanned events may include:

1) Unexpected operational events which cause the equipment to perform the function specified by this Surveillance for which adequate documentation of the required performance is available: and

2) Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component to OPERABLE, provided the maintenance was required, or performed in coniunction with maintenance required to maintain OPERABILITY or reliability.

Tab ..R I I flic table doinoAwtoc, tIo liMite On oioctroiý' level, Peoat veltagoe, and 6pocitic gr*lity tor tFro Elioron"t .atg*..ero. Th I meaning ot eac-ih catog-rly i. iicGused below.

(continued)

Watts Bar-Unit 1 B 3.8-77b

Battery GeHl-Parameters B 3.8.6 BASES SURVEILLANCE T-lable 3.81 (cnrtinRLud)

REQUIREMENTS Category Adefines the normnal paramneterF limit forF each designated pilot coil'i each bailer;. The cells selected as pilot cells are those whose temperature, voltage, and electrolyte specific gravity approximFate the s~tate of charge of the entm~e bate.9e The Category A limits specified for electrolyte level are based ORnmanufacturer recommendations and are consistent With the guidance_ in IrEmEE150 (Ref. 2),

with the extra - inch; allowance above the high water level indication for-operati~gng argi to acoeunt for temperatures and charge effects. In addition to-this allowance, footnote a to Table 3.8.6 1 per~mits the electrolyt level to be above the spec-ifie-d mfaximumA level during equalfizing charge, provided it is; not overflowing. These limffits ensure that the plates suffer no physical damage, and that adequate electFro transfer capability is m~aintafined in the event of transient condtios. EEE 150 (Ref. 2) recommenAds6 that electrolyt4e level readings should be made only after the battery has been at float charge for at least 7:2 hou rs.

The Category A limit specified forfloat voltage iŽ2.13 V per cell. This value i based On the recommendations of IFEEE 150 (Ref. 2), which states that prolonged operation of cells- 2. 13ZcanR reduce the life expectancy of cells.

The Category A limnit specified for specific gravity for each pfilot cell's 1.200 (0.015 below the AAmanufacturer fully charged nominal specific gravity or a batterycharging current that had stabilized at a low.A value). This valu is-characteristic Of a charged cell with adequate capacity. According to IEEE 150-(Ref. 2), the specific gravity readings are based on a temperature of 77 OF (25 PC+.

The specific. gravity readings are corrected for actual electrolye temperature and-level. PFo each 3 OF (1.67 00) above 77 OF (25 2GC,1 point (0.001) is added to the reading; 1 point is subtrac for each 3 OF below 77 OF. The specfic gravity of the electrolyte in a cell'nr ea s with aloss of water dlue to electrolysis Or evape~aeen.

(continued)

Watts Bar-Unit 1 B 3.8-78

Battery Ge*l-Parameters I B 3.8.6 BASES SURVEILLANCE Table 3.8.6 1(continued)

REQUIREMENTS Category B defines the normal paFrameter limits for each connoct1ed ell. Tho termF "connecGted- cell" excludes any batter; coil! that ma" be jumnpered out.

The Category B limits specified for electrolyte level and float voltage are the same as those specified for Category A and have been discussed above. The Categery B limit specified for specific gravity for each GRnlneted cell is, 1.195 (0.020 below the mnanufacturer fully charged, nomninal specific gravity) with the average of all connected cells> 1.205 (0.010 below the m~anufacturer fully charged, nominal specific gravity). These values,are ba-sed on manufacturer's recommFendations. The miiumseific gravity value required for each cell ensueres that the effects of a hihl chredo newly installed coil! Will net m~ask overall degrad-ation of the battery.

Category C defines, the limnits for each coennecrte-d c~ell. These values, although reduced, provide assrUanco that sufficient capacity exists to pe~form. the intenRd-e4 function and maintain a mnargin Of Safety. When any battery parameter is; eotsid' 8-the Category C limits, the assurance Of sufficient capacity described_ -aboveno longer exists, and the battery must be declared inoperable.

The Category C limnits specified for electrel'e level (above the top of the plates m.mait-ain ad-equate electron transfer capability. The&Gatgory C limits for float voltage is, based en IEEE 450 (Ref. 2), which states that a coil' voltage of 2.07-V Or below, und~er float conditions, and not caused by elevated temperaturwe of the cell, iniatsinenl! coiprblems and may reur cl eplacem~ent.

The Category C limi~ts Of avrg speific gravit" 1.195 is basedo mnanufacturer recommendations (0.020 below the (continued)

Watts Bar-Unit 1 B 3.8-79

Battery Gell-Parameters B 3.8.6 BASES SURVEILLANCE Tablo 3.9.6 1 (continued)

REQUIREMENTS manufactuwrernrcmmended fully charged, F)nominal specific gravity). in addition to that 10Alimt, itiFequired that the specific graVity forF each connecte coil mus't be no le-ss than 0-0 below-4 the average of all connecated coils. This limit ensueres that the effect of a highly charged Or new. cýell doAesF Mat m.a-ck oaverall degradation-ef he baftepý-

The footnoter,to Table 3.8.6 1 are applicable to Categor,' A, B3, and C Specific graviy Fotn eth to Table 3m8.6 1 requires the above mentioned correction for electrol'Ae level and temperature, with the eXception that level cerrection is not required when batter; charging current is2 am;pe On float charge) for Vital bteisand 4 1.0 amRps for DG b~atterieS. T-his current provides, in general, an iniainof overall batter,' cOndition.

Becaus8eof specific. gravity gradients that are produced duFrin the recharging process, delays of several days m~ay occur While waiting for the specific gravity to-eot-abilizo. A.Stabilized charger current is an acceptable alternative to specific gravity meaur~ement for determining the state Of charge. T-his phenm oni disc-ussr~ed- in !EgE 150 (Ref. 2). Footnote Gto Table 32.8.6 1 allRows the float charge current to be8 useAd- as an alternate to specific gravity for Up to 31 days folwn a bater; recharge. Within 31 days each connected cell's specific graviy mus~t be m~easreFd to co4fnfr the state of charge. FollGowig a mninre batter; recharge (such as equalizing charge that does- not follow a deep discharge) specific gravity gradients are nEt significant, and confirming measurements may be made in less than 31 days.

REFERENCES 1. Watts Bar FSAR, Section 15, "Accident Analysis," and Section 6, "Engineered Safety Features."

2. IEEE 450 1980/11995, "IEEE Recommended PracticGe for MaintenanGe, Tes6ting, and Replacement of L~arge Lead Storage Batteries for G-.enating Stations and Substations." IEEE Std 450-2002, "IEEE Recommended Practice for Maintenance, Testing and ReDlacement of Vented Lead - Acid Batteries for Stationary Applications," Institute of Electrical and Electronics Engineers, Inc.

3. IEEE Std 485-1983, "IEEE Recommended Practice for Sizing Larme Lead Storage Batteries for Generatinq Stations and Substations," The Institute of Electrical and Electronics Engineers, Inc.

4. Watts Bar FSAR, Section 8, "Electric Power."

Watts Bar-Unit 1 B 3.8-80

ATTACHMENT 3 Proposed WBN Unit 1 TS Changes (Final Typed)

A3-1

DC Sources - Operating 3.8.4 3.8 ELECTRICAL POWER SYSTEMS 3.8.4 DC Sources - Operating LCO 3.8.4 Four channels of vital DC and four Diesel Generator (DG) DC electrical power subsystems shall be OPERABLE.

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

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

2. Spare Vital Chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required Vital chargers.

3. Spare DG Chargers 1A1, 1B1, 2A1, or 2B1 may be substituted for required DG chargers.

4. 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.

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

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

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

AND A.3 Restore vital battery charger 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to OPERABLE status.

B. One required vital battery B.1 Restore vital battery to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable. OPERABLE status.

C. One required vital DC C.1 Restore vital DC channel to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months channel inoperable for OPERABLE status.

reasons other than Condition A or B.

(continued)

Watts Bar-Unit 1 3.8-24

DC Sources - Operating 3.8.4 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. Required Action and D.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion AND Time of Condition A, B, or C not met. D.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months E. One required DG battery E.1 Restore DG battery terminal 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months charger inoperable, voltage to greater than or equal to the minimum established float voltage.

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

< 1 amp.

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

F. One required DG battery F.1 Restore DG battery to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months inoperable. OPERABLE status.

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

other than Condition E or F.

H. Required Action and H.1 Declare associated DG Immediately Associated Completion inoperable.

Time of Condition E, F, or G not met.

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.

(continued)

Watts Bar-Unit 1 3.8-25

DC Sources - Operating 3.8.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY 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 125V 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 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 3.8.4.6 Verify each DG battery charger supplies > 20 amps at 18 months 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 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.

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

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

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

18 months 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 subject to a battery service test.

Watts Bar-Unit 1 3.8-26

DC Sources - Operating 3.8.4 This Page Intentionally Blank Watts Bar-Unit 1 3.8-27

DC Sources - Operating 3.8.4 This Page Intentionally Blank Watts Bar-Unit 1 3.8-28

DC Sources - Operating 3.8.4 This Page Intentionally Blank Waits Bar-Unit 1 3.8-29

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 ----------------------

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

2. Spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers.

3. Spare DG chargers 1A1, 1B1, 2A1, or 2B1 may be substituted for required DG chargers.

4. 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 subsystems.

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

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

subsystems inoperable.

OR A.2.1. Suspend CORE Immediately ALTERATIONS.

AND A.2.2 Suspend movement of Immediately irradiated fuel assemblies.

I_ (continued)

Watts Bar-Unit 1 3.8-30

DC Sources-Shutdown 3.8.5 ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. (continued) AND A.2.3 Initiate action to suspend Immediately operations involving positive reactivity additions.

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

B. One or more required B.1 Declare associated DG Immediately DG DC electrical power inoperable subsystems inoperable.

Watts Bar-Unit 1 3.8-31

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

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 OPERABLE, the following SRs are applicable: In accordance with applicable SRs SR 3.8.4.1 SR 3.8.4.6 SR 3.8.4.2 SR 3.8.4.7 SR 3.8.4.3 SR 3.8.4.4 SR 3.8.4.5 Watts Bar-Unit 1 3.8-32

Battery Parameters 3.8.6 3.8 ELECTRICAL POWER SYSTEMS 3.8.6 Battery Parameters LCO 3.8.6 Battery parameters for required 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within the 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.

CONDITION REQUIRED ACTION COMPLETION TIME A. One required vital battery 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 with one or more battery cells float voltage < 2.07 V. AND 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 float 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months voltage >-2.07 V.

B. One required vital battery B.1 Perform SR 3.8.4.1. 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months with float current > 2 amps.

AND B.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.

C. One required DG battery 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 with one or more battery cells float voltage < 2.07 V. AND 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 float 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months voltage > 2.07 V.

(continued)

Watts Bar-Unit 1 3.8-33

Battery Parameters 3.8.6 CONDITION REQUIRED ACTION COMPLETION TIME D. One required DG battery 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 with float current > 1 amp.

AND 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.

E. One required battery ------------------ NOTE ----------

with one or more cells with electrolyte level less than Required Actions E.1 and E.2 are only electt leelalessthan applicable if electrolyte level was below minimum established the top of plates.

design limits.

E.1 Restore electrolyte level to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months above top of plates.

AND E.2 Verify no evidence of leakage. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months AND E.3 Restore electrolyte level to 31 days greater than or equal to minimum established design limits.

F. One required battery F.1 Restore battery pilot cell 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months with pilot cell electrolyte temperature to greater than or temperature less than equal to minimum established minimum established design limits.

design limits.

G. More than one required vital G.1 Restore battery parameters to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months batteries with battery within limits.

parameters not within limits.

OR More than one required DG batteries with battery parameters not within limits.

(continued)

Watts Bar-Unit 1 3.8-34

Battery Parameters 3.8.6 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME H. Required Action and B.1 Declare associated battery Immediately associated Completion inoperable.

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

OR One required vital battery with one or more battery cells float voltage < 2.07 V and float current > 2 amps.

OR One required DG battery with one or more battery cells float voltage < 2.07V and float current > 1 amp.

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 and DG battery pilot cell. 31 days float voltage is > 2.07 V.

(continued)

Watts Bar-Unit 1 3.8-35

Battery Parameters 3.8.6 SURVEILLANCE REQUIREMENTS (continued)

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

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

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

SR 3.8.6.7 ---------- NOTE---------------

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 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 Watts Bar-Unit 1 3.8-36

Procedures, Programs and Manuals 5.7 5.7 Procedures, Programs, and Manuals 5.7.2.21 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 < 2.13V;

2. Actions to determine whether the float voltage of the remaining battery cells is ? 2.13V when the float voltage of a battery cell has been found to be < 2.13V;

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

ATTACHMENT 4 Proposed WBN Unit I TS Bases Changes (Final Typed)

(For Information Only)

A4-1

DC Sources-Operating B 3.8.4 B 3.8 ELECTRICAL POWER SYSTEMS B 3.8.4 DC Sources - Operating BASES BACKGROUND The station DC electrical power system provides the AC emergency power system with control power. It also provides both motive and control power to selected safety related equipment and preferred AC vital bus power (via inverters). As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1), the DC electrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a single failure. The DC electrical power system also conforms to the recommendations of Regulatory Guide 1.6 (Ref. 2) and IEEE-308 (Ref. 3).

125V Vital DC Electrical Power Subsystem The vital 125V DC electrical power system is a Class IE system whose safety function is to provide control power for engineered safety features equipment, emergency lighting, vital inverters, and other safety-related DC powered equipment for the entire unit. The system capacity is sufficient to supply these loads and any connected nonsafety loads during normal operation and to permit safe shutdown and isolation of the reactor for the "loss of all AC power" condition. The system is designed to perform its safety function subject to a single failure.

The 125V DC vital power system is composed of the four redundant channels (Channels I and III are associated with Train A and Channels II and IV are associated with Train B) and consists of four type lead-acid-calcium batteries, eight battery chargers (including two pairs of spare chargers), four distribution boards, battery racks, and the required cabling, instrumentation and protective features. Each channel is electrically and physically independent from the equipment of all other channels so that a single failure in one channel will not cause a failure in another channel. Each channel consists of a battery charger which supplies normal DC power, a battery for emergency DC power, and a battery board which facilitates load grouping and provides circuit protection.

These four channels are used to provide emergency power to the 120V AC vital power system which furnishes control power to the reactor protection system. No automatic connections are used between the four redundant channels.

Battery boards I, II, Ill, and IV have a charger normally connected to them and also have manual access to a spare (backup) charger for use upon loss of the normal charger.

(continued)

Watts Bar-Unit 1 B 3.8-54

DC Sources-Operating B 3.8.4 BASES BACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Additionally, battery boards 1,11,111,and IV have manual access to the fifth vital battery system. The fifth 125V DC Vital Battery System is intended to serve as a replacement for any one of the four 125V DC vital batteries during their testing, maintenance, and outages with no loss of system reliability under any mode of operation.

Each of the vital DC electrical power subsystems provide the control power for its associated Class 1 E AC power load group, 6.9 kV switchgear, and 480V load centers. The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, they power the emergency DC lighting system.

The vital DC power distribution system is described in more detail in Bases for LCO 3.8.9, "Distribution System - Operating," and LCO 3.8.10, "Distribution Systems - Shutdown."

Each vital battery has adequate storage capacity to carry the required load continuously for at least 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months in the event of a loss of all AC power (station blackout) without an accident or for 30 minutes with an accident considering a single failure. Load shedding of non-required loads will be performed to achieve the required coping duration for station blackout conditions.

Each 125V DC vital battery is separately housed in a ventilated room apart from its charger and distribution centers, except for Vital Battery V. Each subsystem is located 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 between redundant Class 1E subsystems, such as batteries, battery chargers, or distribution panels.

The batteries for the vital DC electrical power subsystems are sized to produce required capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the 100% design demand. The criteria for sizing large lead storage batteries are defined in IEEE-485 (Ref.5).

The battery cells are of flooded lead acid construction with a nominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum output voltage is 120V, for a 60 cell battery (vital battery) the total minimum output voltage is 124V and for a 62 cell battery (5 th vital battery) the total minimum output voltage is 128V. The open circuit voltage is the voltage maintained when there is no charging or discharging. Once fully charged the battery cell will maintain approximately 97% of its capacity for 30 days without further charging per manufacturer's instructions. Optimal long term performance however, is obtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This provides adequate over-potential, which limits the formation of lead sulfate and self discharge.

(continued)

Watts Bar-Unit 1 B 3.8-55

DC Sources-Operating B 3.8.4 BASES BACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Each Vital DC electrical power subsystem has ample power output capacity for the steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged. Each battery charger also has sufficient capacity to restore the battery bank from the design minimum charge to its fully charged state within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months (with accident loads being supplied) following a 30 minute AC power outage and in approximately 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months (while supplying normal steady state loads following a 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months AC power outage) (Ref. 6).

The battery charger is normally 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. This assures the internal losses of a battery are overcome and the battery is maintained in a fully charged state.

When desired, the charger can be placed in the equalize mode. The equalize mode is at a higher voltage than the float mode and charging current is correspondingly higher. The battery charger is operated in the equalize mode after a battery discharge or for routine maintenance. Following a battery discharge, the battery recharge characteristic accepts current at the current limit of the battery charger (if the discharge was significant, e.g., following a battery service test) until the battery terminal voltage approaches the charger voltage setpoint. Charging current then reduces exponentially during the remainder of the recharge cycle. Lead calcium batteries have recharge efficiencies of greater than 91%, so once at least 110% of the ampere-hours discharged have been returned, the battery capacity would be restored to the same condition as it was prior to the discharge. This can be monitored by direct observation of the exponentially decaying charging current or by evaluating the amp-hours discharged from the battery and amp-hours returned to the battery.

125V Diesel Generator (DG) DC Electrical Power Subsystem Control power for the DGs is provided by five DG battery systems, one per DG.

Each system is comprised of a battery, a dual battery charger assembly, distribution center, cabling, and cable ways. The DG 125V DC control power and field-flash circuits have power supplied from their respective 125V distribution panel. The normal supply of DC current is from the associated charger. The battery provides control and field-flash power when the charger is unavailable.

The charger supplies the normal DC loads, maintains the battery in a fully charged condition, and recharges (480V AC available) the battery while supplying the required loads regardless of the status of the unit. The batteries are physically and electrically independent. The battery has sufficient capacity when fully charged to supply required loads for a minimum of 30 minutes following a loss of normal power. Each battery is normally required to supply loads during the time interval between loss of normal feed to its charger and the receipt of emergency power to the charger from its respective DG.

Watts Bar-Unit 1 B 3.8-56

DC Sources-Operating B 3.8.4 BASES APPLICABLE The initial conditions of Design Basis Accident (DBA) and SAFETY ANALYSES transient analyses in FSAR, Section 6 (Ref. 7), and in FSAR, Section 15 (Ref. 7),

assume that the Engineered Safety Feature (ESF) systems are OPERABLE.

The vital DC electrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control power for switching during all MODES of operation. The DG battery systems provide DC power for the DGs. The OPERABILITY of the DC sources is consistent with the initial assumptions of the accident analyses and is based upon meeting the design basis of the plant. This includes maintaining the DC sources OPERABLE during accident conditions in the event of:

a. An assumed loss of all offsite AC power or all onsite AC power; and

b. A worst case single failure.

The DC sources satisfy Criterion 3 of the NRC Policy Statement.

LCO Four 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 supplying power to the associated DC bus within the channel; and four DG DC electrical power subsystems each consisting of a battery, a dual battery charger assembly, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE to ensure the availability of the required power to shut down the reactor and maintain it in a safe condition after an anticipated operational occurrence (AOO) or a postulated DBA. Loss of any DC electrical power subsystem does not prevent the minimum safety function from being performed (Ref. 4).

An OPERABLE vital DC electrical power subsystem requires all required batteries and respective chargers to be operating and connected to the associated DC buses.

The LCO is modified by four Notes. Note 1 indicates that Vital Battery V may be substituted for any of the required vital batteries. However, the fifth battery I

cannot be declared OPERABLE until it is connected electrically in place of another battery and it has satisfied applicable Surveillance Requirements. Note 2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vital chargers. Note 3 indicates that spare DG chargers 1Al, 1 B1, 2A1, or 2B1 may be substituted for required DG chargers. However, the spare charger(s) cannot be declared OPERABLE until it is connected electrically in place of another charger, and it has satisfied applicable Surveillance Requirements. Note 4 indicates that the C-S DG and its associated DC subsystem may be substituted for any of the required DGs. However, the C-S DG and its associated DC subsystem cannot be declared OPERABLE until it is connected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.

Watts Bar-Unit 1 B 3.8-57

DC Sources-Operating B 3.8.4 BASES APPLICABILITY The four vital DC electrical power sources and four DG DC electrical power sources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safe plant operation and to ensure that:

a. Acceptable fuel design limits and reactor coolant pressure boundary limits are not exceeded as a result of AOs or abnormal transients; and

b. Adequate core coolingis provided, and containment integrity and other vital functions are maintained in the event of a postulated DBA.

The DC electrical power requirements for MODES 5 and 6 are addressed in the Bases for LCO 3.8.5, "DC Sources - Shutdown."

ACTIONS A.1, A.2, A.3, E.1, E.2, and E.3 Conditions A and E represent one channel with one battery charger inoperable (e.g., the voltage limit of SR 3.8.4.1 or SR 3.8.4.2 is not maintained). The 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 reasonable time period. Required Actions A.1 and E.1 require that the battery.

terminal voltage 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 . This time provides for returning the inoperable charger to OPERABLE status or providing an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established float voltage. Restoring the battery terminal voltage to greater than or equal to the minimum established float voltage provides good assurance that, within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , the battery will be restored to its recharged condition from any discharge that might have occurred due to the charger inoperability.

A discharged battery having terminal voltage of at least the minimum established float voltage indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. The time to return a battery to its fully charged state under this condition is simply a function of the amount of the previous discharge and the recharge characteristic of the battery. Thus there is.

good assurance of fully recharging the battery within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , avoiding a premature shutdown with its own attendant risk.

If battery terminal float voltage cannot 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 , and the charger is not operating in the current-limiting mode, a faulty charger is indicated. A faulty charger that is incapable of maintaining established battery terminal float voltage does not provide assurance that it can revert to and operate properly in the current limit mode that is necessary during the recovery period following a battery discharge event that the DC system is designed for.

If the charger is operating in the current limit mode after 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months that is an indication that the battery is partially discharged and its capacity margins will be reduced. The time to return the battery to its fully charged condition in this case is a function of the battery charger capacity, the amount of loads on the associated (continued)

Watts Bar-Unit 1 B 3.8-58

DC Sources-Operating B 3.8.4 BASES ACTIONS DC system, the amount of the previous discharge, and the recharge characteristic of the battery. The charge time can be extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

Required Actions A.2 and E.2 require that the battery float current be verified less than or equal to 2 amps for the vital battery and less than or equal to 1 amp for the DG battery. This indicates that, if the battery had been discharged as the result of the inoperable battery charger, it is now fully capable of supplying the maximum expected load requirement. The 2 amp value for the vital battery and the 1 amp value for the DG battery are based on returning the battery to 98%

charge and assume a 2% design margin for the battery. If at the expiration of the initial 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months period the battery float current is not less than or equal to 2 amps for the vital battery or 1 amp for the DG battery, then this indicates there may be additional battery problems and the battery must be declared inoperable.

Required Actions A.3 and E.3 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., balance of plant non-Class 1 E battery charger). The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion Time reflects a reasonable time to effect restoration of the qualified battery charger to OPERABLE status.

B.1 and F.1 Conditions B.1 and F.1 represent one channel (subsystem) with one battery inoperable. With one battery inoperable, the DC bus is being supplied by the OPERABLE battery charger. Any event that results in a loss of the AC bus supporting the battery charger will also result in loss of DC to that subsystem.

Recovery of the AC bus, especially if it is due to a loss of offsite power, will be hampered by the fact that many of the components necessary for the recovery (e.g., diesel generator control and field flash circuits, AC load shed and diesel generator output circuit breakers, etc.) will likely rely upon the battery. In addition any DC load transients that are beyond the capability of the battery charger and normally require the assistance of the battery will not be able to be brought online. The 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months limit allows sufficient time to effect restoration of an inoperable battery given that the majority of the conditions that lead to battery inoperability (e.g., loss of battery charger, battery cell voltage less than 2.07 V, etc.) are identified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specific Completion Times.

C.1 and G.1 Conditions C.1 and G.1 represent a loss of one DC electrical power subsystem to completely respond to an event, and a potential loss of ability to remain energized during normal operation. It is therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete loss of DC power to the affected subsystem. The 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months limit is consistent with the allowed time for an inoperable DC distribution subsystem.

If one of the required DC electrical power subsystems is inoperable for reasons other than Conditions A or B for the vital batteries or Conditions E or F for the DG (continued)

Watts Bar-Unit 1 B 3.8-59

DC Sources-Operating B 3.8.4 BASES ACTIONS DC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accident condition. Since a subsequent worst case single failure could, however, result in the loss of the minimum necessary DC electrical subsystems to mitigate a worst case accident, continued power operation should not exceed 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months . The 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months Completion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects a reasonable time to assess unit status as a function of the inoperable DC electrical power subsystem and, if the DC electrical power subsystem is not restored to OPERABLE status, to prepare to effect an orderly and safe unit shutdown.

D.1 and D.2 If the inoperable Vital DC electrical power subsystem cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. The Completion Time to bring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).

H.1 If the DG DC electrical power subsystem cannot be restored to OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must be immediately declared inoperable.

This declaration also requires entry into applicable Conditions and Required Actions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."

SURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2 REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the battery chargers, which support the ability of the batteries to perform their intended function. Float charge is the condition in which the charger is supplying the continuous charge required to overcome the internal losses of a battery (or battery cell) and maintain the battery (or a battery cell) in a fully charged state while supplying the continuous steady state loads of the associated DC subsystem. On float charge, batterycells will receive adequate current to optimally charge the battery. The 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. For example the minimum nominal terminal voltage for the 5th Vital Battery is 136V (62 cells times 2.20 Vpc), the minimum nominal terminal voltage for the vital batteries is 132V (60 cells times 2.20 Vpc) and the minimum nominal terminal voltage for the DG batteries is 128V (58 cells times 2.20 Vpc). These voltage levels maintain the battery plates in a condition that supports maintaining the grid life.

(continued)

Watts Bar-Unit 1 B 3.8-60

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE The voltage requirements listed above are based on the critical design voltage of REQUIREMENTS the battery and are consistent with the initial voltages assumed in the battery sizing calculations. The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).

SR 3.8.4.3 Verifying that for the vital batteries that the alternate feeder breakers to each required battery charger is open ensures that independence between the power trains is maintained. The 7-day Frequency is based on engineering judgment, is consistent with procedural controls governing breaker operation, and ensures correct breaker position.

SR 3.8.4.4 This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning properly, with all required circuit breakers closed and buses energized from normal power. The 7 day Frequency takes into account the redundant DG capability and other indications available in the control room that will alert the operator to system malfunctions.

SR 3.8.4.5 and SR 3.8.4.6 These SRs verify the design capacity of the vital and DG battery chargers.

According to Regulatory Guide 1.32 (Ref. 6), the battery charger supply is recommended to be based on the largest combined demands of the various steady state loads and the charging capacity to restore the battery from the design minimum charge state to the recharged state, irrespective of the status of the unit during these demand occurrences. Verifying the capability of the charger to operate in a sustained current limit condition ensures that these requirements can be satisfied.

The SRs provide two options. One option requires that each vital battery charger be capable of supplying 200 amps (20 amps for the DG battery charger) at the minimum established float voltage for 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . Recharging the battery or testing for a minimum of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months is sufficient to verify the output capability of the charger can be sustained, that current limit adjustments are properly set and that protective devices will not inhibit performance at current limit settings.

The other option requires that each battery charger be capable of recharging the battery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the status of the plant during which these demands occur). This level of loading may not normally be available following the battery service test and will need to be supplemented with additional loads. The duration for this test may be longer than the charger sizing criteria since the battery recharge is affected by float voltage, temperature, and the exponential decay in charging current. The battery is recharged when the measured charging current is < 2 amps for the vital batteries and : 1 for the DG batteries.

The Surveillance Frequency is acceptable, given the plant conditions required to perform the test and the other administrative controls existing to ensure adequate charger performance during these 18 month intervals. In addition, this Frequency is intended to be consistent with expected fuel cycle lengths.

(continued)

Watts Bar-Unit 1 B 3.8-61

DC Sources-Operating B 3.8.4 BASES SURVEILLANCE SR 3.8.4.7 REQUIREMENTS A battery service test is a special test of battery capability, as found, to satisfy the design requirements (battery duty cycle) of the DC electrical power system. The discharge rate and test length should correspond to worst case design duty cycle requirements based on References 10 and 12.

The Surveillance Frequency of 18 months is consistent with the recommendations of Regulatory Guide 1.32 (Ref.6) and Regulatory Guide 1.129 (Ref.1 1), which state that the battery service test should be performed during refueling operations or at some other outage, with intervals between tests, not to exceed 18 months.

This SR is modified by two Notes. Note 1 allows the performance of a modified performance discharge test in lieu of a service test. The modified performance discharge test is a simulated duty cycle consisting of just two rates; the one minute rate published for the battery or the largest current load of the duty cycle, followed by the test rate employed for the performance test, both of which envelope the duty cycle of the service test. Since the ampere-hours removed by a rated one minute discharge represents a very small portion of the battery capacity, the test rate can be changed to that for the performance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge test should remain above the minimum battery terminal voltage specified in the battery service test for the duration of time equal to that of the service test.

Note 2 allow the plant to take credit for unplanned events that satisfy this SR.

Examples of unplanned events may include:

1) Unexpected operational events which cause the equipment to perform the function specified by this Surveillance, for which adequate documentation of the required performance is available; and

2) Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component to OPERABLE, provided the maintenance was required, or performed in conjunction with maintenance required to maintain OPERABILITY or reliability.

Watts Bar-Unit 1 B 3.8-62

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DC Sources-Operating B 3.8.4 BASES REFERENCES 1. Title 10, Code of Federal Regulations, Part 50, Appendix A, General Design Criterion 17, "Electric Power System."

2. Regulatory Guide 1.6, "Independence Between Redundant Standby (Onsite) Power Sources and Between Their Distribution Systems," U.S.

Nuclear Regulatory Commission, March 10, 1971.

3. IEEE-308-1971, "IEEE Standard Criteria for Class 1E Power Systems for Nuclear Power Generating Stations," Institute of Electrical and Electronic Engineers.

4. Watts Bar FSAR, Section 8.3.2, "DC Power System."

5. IEEE-485-1983, "Recommended Practices for Sizing Large Lead Storage Batteries for Generating Stations and Substations," Institute of Electrical and Electronic Engineers.

6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric Power Systems for Nuclear Power Plants," February 1977, U.S. Nuclear Regulatory Commission.

7. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6 "Engineered Safety Features."

8. Regulatory Guide 1.93, "Availability of Electric Power Sources," U.S.

Nuclear Regulatory Commission, December 1974.

9 IEEE-450-2002, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Vented Lead - Acid Batteries for Stationary Applications," Institute of Electrical and Electronics Engineers, Inc.

10. TVA Calculation EDQ00023620070003, "125V DC Vital Battery System Analysis."

11. Regulatory Guide 1.129, "Maintenance Testing and Replacement of Large Lead Storage Batteries for Generating Stations and Subsystems,"

U.S. Nuclear Regulatory Commission, February 1978.

(continued)

Watts Bar-Unit 1 B 3.8-68

DC Sources-Operating B 3.8.4 BASES REFERENCES 12. iVA Calculation WBN EEB-MS-TI1 1-0062, "125 V DC Diesel Generator (continued) Control Power System Evaluation"