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{{#Wiki_filter:Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402August 28, 201310 CFR 50.90ATTN: Document Control DeskU.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1Facility Operating License No. NPF-90NRC 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 LicenseNo. 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, "DCSources-Shutdown,"
and TS 3.8.6, "Battery Cell Parameters."
This amendment requestincludes changes consistent with both Technical Specifications Task Force (TSTF) changetraveler 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 thatare appropriate to the WBN Unit 1 design, because the direct current (DC) electrical powerdistribution system referenced in the model application is significantly different the system thatexists at Watts Bar. Furthermore, due to these differences, TVA has not utilized the modelapplication for TSTF-500, but has provided plant specific justifications for the related TSTF-500changes being proposed in this LAR. In addition to the TSTF-360 and TSTF-500 relatedchanges, editorial and clarification changes are being made to TS 3.8.4, 3.8.5, and 3.8.6.Enclosure 1 to this letter provides a description, technical evaluation, regulatory evaluation, andenvironmental 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 3and 4 to the enclosure provide the existing TS and Bases pages retyped with the proposedchanges incorporated.
Prin~ted on recycled paper I c c U.S. Nuclear Regulatory Commission Page 2August 28, 2013Attachment 5 to the enclosure contains a letter from the battery manufacturer verifying theacceptability of using float current monitoring as a reliable and accurate indication of thestate-of-charge of the battery, which will hold true over the life of the battery.
Attachment 6 tothe enclosure is a schematic diagram of the WBN 120V AC and 125V DC Vital Plant ControlPower System for information only.TVA requests approval of this TS change by August 30, 2014, and will implement revised TSswithin six months of NRC approval.
TVA has determined that there are no significant hazards considerations associated with theproposed 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 Boardhave 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 andenclosures to the Tennessee State Department of Environment and Conservation.
Enclosure 2 provides the list of regulatory commitments associated with this LicenseAmendment 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 the28th day of August 2013.Respe u y,J. .hkeaVi e P \sident, Nuclear Licensing Enclosure cc: See Page 3 U.S. Nuclear Regulatory Commission Page 3August 28, 2013
==Enclosures:==
: 1. Evaluation of Proposed Change2. List of Regulatory Commitments cc (Enclosures):
NRR Project Manager -Watts Bar Nuclear Plant, Unit 1NRC Regional Administrator
-Region IINRC Resident Inspector
-Watts Bar Nuclear Plant, Unit 1NRC Resident Inspector
-Watts Bar Nuclear Plant, Unit 2Director, Division of Radiological Health -Tennessee State Department of Environment and Conservation ENCLOSURE 1TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT UNIT 1EVALUATION 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 BatteryState of Charge6. 120V AC & 125V DC Vital Plant Control Power System DiagramE1-1 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 1Technical Specification (TS) requirements related to direct current (DC) electrical systems inTS 3.8.4, "DC Sources -Operating,"
TS 3.8.5, "DC Sources -Shutdown,"
and TS 3.8.6, "BatteryCell Parameters."
In addition, a new "Battery Monitoring and Maintenance Program" is beingproposed 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 batterycharger and alternate testing criteria in the applicable Surveillance Requirements (SRs). Theproposed changes also include the relocation of a number of SRs in TS 3.8.4 that performpreventive maintenance on the safety-related batteries to a licensee-controlled program.
Theproposed 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, andelectrolyte temperature to TS 3.8.6. Specific SRs are also being proposed for verification ofthese parameters.
A new program is being proposed as TS 5.7.2.21 for the maintenance and monitoring of stationbatteries.
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 toTSTF-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 fromthat which exists at Watts Bar, the proposed TS changes are based on those TSTF-360 andTSTF-500 changes that are appropriate to the WBN Unit 1 design. Furthermore, due to thesedifferences, TVA has not utilized the model application for TSTF-500, but has provided plantspecific justifications for the related TSTF-500 changes being proposed in this LAR. In additionto the TSTF-360 and TSTF-500 related changes, editorial and clarification changes are beingmade 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 assome clarification changes to these three Technical Specifications are being proposed toimprove the use and readability of TSs 3.8.4, TS 3.8.5, and TS 3.8.6.E1-2 of 29 2.0 DETAILED DESCRIPTION
===Background===
Vital 125V DC Control Power SystemThe Vital 125 volt (V) DC Control Power System is a Class 1 E DC electrical power system(Reference
: 4) that provides control power to the emergency alternating current (AC) powersystem (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 1and 2. Each channel consists of a battery charger that supplies normal DC power, a battery foremergency DC power, and a battery board to facilitate load grouping and provide circuitprotection.
Loads are assigned according to their divisional requirements and are shared with WBN Units 1and 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) andTrain 1 B and 2B (load group B) and are primarily associated with the ESF systems.
One loadgroup can mitigate a design basis accident on one unit and safely shut down the other unitassuming 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 Vshutdown boards are provided by Channels I and III and for load group B, by Channels IIand 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 useupon loss of the normal charger.
Each pair of spare chargers is mechanically interlocked suchthat 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 DCVital Battery System is intended to serve as a replacement for any one of the four 125V DC vitalbatteries during testing, maintenance, and outages with no loss of system reliability under anymode 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 differssubstantially from the standard plant design assumed in TSTF-500 and the model NRC SafetyEvaluation for the TSTF. The DC System design referenced in TSTF-500 consists of twoindependent and redundant DC power trains per unit. As discussed above, the WBN Unit 1125V DC Vital Control Power Systems consists of four redundant channels that are shared withWBN 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 360and 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. TheDC electrical power system is designed to have sufficient independence, redundancy, andtestability 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. Incase of loss of normal power to the battery charger, the DC load is automatically powered fromthe station batteries.
E1-3 of 29 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 theother subsystem to ensure that a single failure in one subsystem does not cause a failure in aredundant 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 inthe 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 andother factors.Each DC electrical power subsystem battery charger has ample power output capacity for thesteady state operation of connected loads required during normal operation, while at the sametime maintaining its battery bank fully charged.
Each battery charger also has sufficient excesscapacity to restore the battery from the design minimum charge to its fully charged state whilesupplying normal steady state loads.Each battery charger is normally in the float-charge mode. Float-charge is the condition inwhich the charger is supplying the connected loads and the battery cells are receiving adequatecurrent to optimally charge the battery.
The purpose of the float-charge is to overcome theinternal 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 eachchannel.
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 DCduring an equalizing charge period (all loads can tolerate the 140 volt equalizing voltage).
Thecharger supplies normal steady state DC load demand on the battery board and maintains thebattery in a charged state. Normal recharging of the battery from the design discharged condition can be accomplished in approximately 12 hours (with accident loads being supplied) following a 30-minute AC power outage and in approximately 36 hours (with normal loads beingsupplied) following a 4-hour AC power outage. The battery chargers, including the sparechargers if in service, are automatically loaded on the diesel generators following a loss ofoffsite 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 assignedchannels.
It can also be substituted for or operate in parallel with the normal charger in thatchannel.Alternating current power for each charger is derived from the station auxiliary power system viatwo 480V AC 3-phase circuits which are physically and electrically independent.
Each circuithas 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 transferswitches are mechanically interlocked to prevent closing switches in a manner to parallel bothfeeds. The alternate 480V feeder breakers are verified open in accordance with the TSs. Eachcharger 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 powerto 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 toa nominal 125V DC output having a rated capacity of 200 amperes.
Over this output currentE1-4 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 ratedoutput;(4) protective devices which prevent a failed charger from discharging its associated batteryand 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 anover-voltage condition.
The chargers normally operate in the float mode at 135V DC for Batteries I through IV and138.5V DC for Battery V. The maximum equalizing voltage for Batteries I through IV is140V DC when connected to the distribution system. The system configuration, usingsubstitution of Battery V, permits off-line equalization at higher than normal values.Emer-gency DC SupplyThe emergency supply of DC current to each distribution board is from its associated vitalbattery.
There are five vital batteries for the plant; one associated with each channel and VitalBattery V, which serves as a temporary replacement for Vital Battery 1, 11, 111 or IV. Thesebatteries are physically and electrically independent.
The vital batteries supply the entire plantDC 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 unitscontinuously for 30 minutes.
The batteries also have the capability to supply the essential loadsrequired to maintain the plant in a safe shutdown condition for four hours following a loss of allnormal and standby AC power, but no accident (i.e., a station blackout).
Each battery isnormally required to supply loads only during the time interval between loss of normal feed to itscharger and the receipt of emergency power to the charger from the standby diesel generator (DG).Diesel Generator 125V DC Control SystemA 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 DCcontrol power and field-flash when the charger is unavailable.
If 480V AC is available, thecharger supplies the normal DC loads, maintains the battery in a fully charged condition, andrecharges 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 areungrounded 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 aloss of normal power. Battery capacity design requirements consider minimum required voltagefor loads and the effects of aging and ambient temperature.
Each battery is normally required tosupply loads only during the time interval between loss of normal feed to its charger and thereceipt 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 of105V 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.
Eachcharger maintains a float voltage of approximately 130V DC on the associated battery boardwith the battery connected to the board and is capable of maintaining 135V DC during anequalizing 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 ACsource from two respective 480V AC Diesel Generator Auxiliary Boards. If the normal charger isunavailable, the alternate charger is selected by the 125V DC transfer switch included in theassembly.
The charger is a solid-state type which converts a 3-phase 480V AC input to anominal 125V DC output. The DC output voltage will vary no more than +/- 1.0% for a supplyvoltage 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 modeat 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 ChangesThe 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) foran 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 alicensee-controlled program.
This focuses TS requirements on the analysis basis safetyfunction of the battery.The proposed TS changes are as following.
* Revise 3.8.4, "DC Sources Operating" to add Conditions for inoperable battery chargersand inoperable batteries, and relocate SRs on battery corrosion, connection resistance, and visual inspection, to the new Battery Monitoring and Maintenance Program.
Allowuse of the Modified Performance testing to satisfy SRs for Service Testing andPerformance Testing." Revise the list of TS 3.8.4 SRs in TS 3.8.5, "DC Sources -Shutdown,"
that must be metto 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 meetCategory A and B limits to the new Battery Monitoring and Maintenance Program.E1-6 of 29 Retain Category C limits for cell float voltage and electrolyte level in new proposedTS. 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 inAttachment 1 to this Enclosure 2.2 Need for Proposed ChangesWBN Unit 1 Technical Specifications were initially written and approved by the NRC based onthe original revision of NUREG-1431, "Standard Technical Specifications
-Westinghouse Plants."
Since the issuance of Revision 0, many changes have been made to NUREG-1431 toenhance,
: improve, and clarify the Technical Specifications.
One area of enhancements andimprovements is in the area of DC sources, TSs 3.8.4, TS 3.8.5, and TS 3.8.6. WBN Unit 1 hasnot previously updated the WBN Unit 1 Technical Specification to include two of the majorchanges 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 andclarification 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 asdescribed below.3.1.1 LCO 3.8.4 NotesThe 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 vitalchargers.
: 3. Spare DG Battery Chargers 1Al, 1 B1, 2A1, or 2B1 may be substituted for requiredDG chargers.
: 4. The C-S DG and its associated DC electrical power subsystem may be substituted forany of the required DGs and their associated DC electrical power subsystem.
Technical Justification for LCO 3.8.4 Note changesExisting Note 2 is renumbered Note 4. New Notes 2 and 3 allow substitution of the spare vitalbattery and DG battery chargers for the required battery chargers.
The spare battery chargersare fully qualified and appropriately sized to perform their design safety function as those beingreplaced.
The description of the chargers, both normal and spare (also identified as alternate) is provided in Section 2.0 (Background) of this enclosure.
E1-7 of 29 3.1.2 TS 3.8.4 Actions A and EThe proposed change adds new Conditions A and E to address the conditions in which onerequired vital battery charger on one channel (Condition A) or one required DG battery chargeron one train (Condition E) is inoperable.
The proposed change increases the Completion Time(CT) for an inoperable battery charger from the existing 2 hours in current Required Actions A. 1and C.1 to 72 hours in proposed Required Actions A.3 and E.3, provided that battery terminalvoltage is restored to greater than or equal to the minimum established float voltage within2 hours (Required Actions A.1 and E.1), and battery float current is verified to be less than orequal to 2 amps for the vital battery and 1 amp for the DG battery once per 12 hours (Required Actions A.2 and E.2).Technical Justification for TS 3.8.4 Actions A and E changesNew 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) isinoperable.
The term "required" is added since there are spare chargers, as stated anddiscussed in proposed Notes 2 and 3 (i.e., not all installed chargers are required by the LCO tobe operable).
There are three associated Required Actions for new Conditions A and E. TheRequired Actions provide a tiered response that focuses on returning the battery to the fullycharged 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 thanor equal to the minimum established float voltage within 2 hours. Required Actions A.2 and E.2require the vital battery float current to be verified to be < 2 amps and the DG battery floatcurrent to be verified to be < 1 amp once per 12 hours. Required Actions A.3 and E.3 requirethe battery charger to be restored to operable status within 72 hours.New Required Actions A.1 and E.1 provide assurance that a battery discharge is terminated byrequiring that the battery terminal voltage be restored to greater than or equal to the minimumestablished float voltage within 2 hours. The battery charger, in addition to maintaining thebattery operable, provides DC control power to AC circuit breakers and thus supports therecovery 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 operablestatus or for reestablishing an alternate means of restoring battery terminal voltage to greaterthan or equal to the minimum established float voltage.
This provides assurance that thebattery will be restored to its fully charged condition from any discharge that might haveoccurred due to the battery charger being inoperable.
At the end of the 2 hours, a terminalvoltage of at least the minimum established float voltage provides indication that the battery ison the exponential charging current portion of its recharging cycle.New Required Actions A.2 and E.2 require that once per 12 hours, the battery float current beverified to be < 2 amps for the vital battery and < 1 amp for the DG battery.
This confirms that ifthe battery has been discharged as the result of an inoperable battery charger, it had beenrecharged.
If at the expiration of the 12-hour period, the float current for the vital battery isgreater 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 toperform its safety function.
New Required Actions A.3 and E.3 require restoring the inoperable battery charger to operablestatus within 72 hours. The presumptions that: (1) the DC bus remains energized; (2) thebattery discharge is terminated based on restoration of the battery terminal voltage (NewE1-8 of 29 Required Actions A.1 and E.1); and (3) the battery is fully recharged based upon battery floatcurrent (New Required Actions A.2 and E.2), establish a basis for extending the restoration timefor an inoperable battery charger beyond the existing 2-hour CT to 72 hours (New RequiredActions A.3 and E.3).3.1.3 TS 3.8.4 Actions B and FThe proposed change would add new Actions B and F, which would apply when one requiredvital battery on one channel or one required DG battery on one train is inoperable.
Theproposed Required Action would state that the battery must be restored to operable statuswithin 2 hours.Technical Justification for TS 3.8.4 Actions B and F changesWith batteries on one channel or train inoperable, the DC bus is being supplied by an operablebattery charger(s).
Any event that results in a loss of the AC bus supporting the batterycharger(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 anddiesel 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 thelimiting 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 allowedRequired Actions and associated CTs. In addition, these proposed Actions are consistent withcurrent TS 3.8.4 Actions A and C, which currently apply to the condition of one inoperable vitalbattery 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 "forreasons other than Condition A or B" is added to renumbered Condition C. Existing Condition Cis renumbered to Condition G and the exception "for reasons other than Condition E or F" isadded to renumbered Condition G. Existing Condition B is renumbered to Condition D and thephrase "of Condition A" is changed to "of Condition A, B, or C." Existing Condition D isrenumbered 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 changesThe proposed change is editorial in nature and will not result in new requirements or changeoperational restrictions or flexibility.
The Conditions are renumbered and the additional wordsadded to the Conditions due to the addition of the proposed Actions A, B, E, and F, asdescribed in subsections 3.1.2 and 3.1.3 above.3.1.5 SR 3.8.4.1 and SR 3.8.4.2SR 3.8.4.1The 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 thanor equal to the minimum established float voltage."
The frequency of 7 days remainsE1-9 of 29 unchanged.
The value for the minimum established float voltage is removed from the this TSand controlled by the new TS 5.7.2.21 (described below in section 3.4).SR 3.8.4.2The proposed change revises SR 3.8.4.2 from "Verify DG battery terminal voltage is > 124V onfloat charge" to "Verify DG battery terminal voltage is greater than or equal to the minimumestablished float voltage."
The frequency of 7 days remains unchanged.
The value for theminimum established float voltage is removed from this TS and controlled by the newTS 5.7.2.21 (described below in section 3.4).Technical Justification for SR 3.8.4.1 and SR 3.8.4.2 changesThis change removes specific terminal voltage criteria currently identified in SR 3.8.4.1 andSR 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 terminalvoltage while the system is on a float charge to ensure the effectiveness of the battery chargeris not degraded.
The battery terminal voltage selected by the battery manufacturer is theminimum voltage which ensures an optimum charging voltage is applied to the battery.
Theminimum established float voltage will maintain the battery plates in a condition that supportsoptimizing battery grid life. Maintaining this voltage limit ensures that the battery will be capableof 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 thosethat represent the lowest voltage cells in the battery.
This ensures that the other cells should beabove 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 3.8.4.10The 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 physicaldamage),
SR 3.8.4.8 (remove visible corrosion and ensure that connections are clean andtight), and SR 3.8.4.9 and SR 3.8.4.10 (verification of connection resistance for vital andDG 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, andSR 3.8.4.10 changesThe 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 theSurveillance 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 batteryterminals for signs of corrosion, as required by SR 3.8.4.5, SR 3.8.4.6, SR 3.8.4.7 andSR 3.8.4.8, to ensure that connections are clean and tight are generally considered a routinepreventive 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 thepost and the connector).
: However, visual .inspection of the battery terminals alone does notprovide an indication of a battery's capability to perform its design function.
Therefore, TVAconcludes that these activities are preventive maintenance and that the parameters can beadequately controlled in the new TS 5.7.2.21.
El-10 of 29 With regard to the resistance verifications of SR 3.8.4.9 and SR 3.8.4.10, the existing valuesrepresent limits at which some action should be taken, not necessarily when the operability ofthe 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.
Betweensurveillances, the resistance of each battery inter-cell connection varies independently from allthe others. Some of these connection resistance values may be higher or lower than others, andthe 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, theseactivities are more appropriately controlled under the proposed Battery Monitoring andMaintenance Program (TS 5.7.2.21).
3.1.7 SR 3.8.4.11 and 12The 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 capableof supplying the minimum charging current at the minimum established float voltage for at least4 hours. The second test allowance (SR 3.8.4.5 and SR 3.8.4.6 second test allowance) addsacceptance criteria as to the time required to recharge the battery (24 hours) and clarifies thatduring the recharging, the charger must also be supplying the largest combined demands of thevarious 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 basisevent discharge state, in lieu of the current requirement to start the test after a service orcapacity discharge test. The proposed change also deletes the Notes for SR 3.8.4.11 andSR 3.8.1.12.
Technical Justification for TS SR 3.8.4.11 and SR 3.8.4.12 changesRenumbering 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 batterycharger current requirements for each DC source, and its purpose is to verify the designcapacity of each battery charger.
The voltage requirements are based on the battery chargervoltage level after a response to a loss of AC power. Battery manufacturers establish thisvoltage limit to provide the optimum charge on the battery and to maintain the battery plates in acondition that supports maintaining the battery grid life. Maintaining this voltage limit shouldensure 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 torepresent the lowest voltage cells in the battery.
This should ensure that the other cells areabove 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."El-11 of 29 The proposed alternate test method is revised to:"Verify each vital [DG] battery charger can recharge the battery to the fully charged state within24 hours while supplying the largest combined demands of the various continuous steady stateloads, 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 notbe sufficient to demonstrate battery charger capability following the battery service test orcapacity discharge test and may need to be supplemented with additional loads. The duration ofthis test may be longer than the charger sizing criteria since the battery recharge is affected byfloat voltage, temperature, and the exponential decay in charging current.
If each batterycharger is capable of recharging its respective battery within 24 hours while supplying thelargest combined demands of the various continuous steady state loads, after a batterydischarge to the design minimum discharge state, the proposed alternate testing criteria wouldsatisfy 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 toeliminate 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 betaken 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 inorder to perform the two SRs for the normal chargers.
The spare chargers are allowed tosubstitute for the normal chargers, as described in Section 3.1.1 above. Therefore, norestriction on performing these SRs during Modes 1, 2, 3, and 4 are required and at least onemethod of verifying charger OPERABILITY can be performed in MODE 1, 2, 3, or 4 withoutaffecting plant safety.3.1.8 SR 3.8.4.13The 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 byperforming the modified performance discharge test instead of the service discharge test.Technical Justification for TS SR 3.8.4.13 changeTVA proposed revising Note 1 to SR 3.8.4.13 (new SR 3.8.4.7) to eliminate the "once per 60months" limitation for satisfying the SR by performing the modified performance discharge testinstead 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 themodified performance discharge test for the vital batteries completely encompasses the loadprofile of the battery service discharge test. TVA commits to confirming that the modifiedperformance discharge test for the DG batteries completely encompasses the load profile of thebattery service discharge test.El-12 of 29 3.1.9 SR 3.8.4.14The proposed change moves SR 3.8.4.14 to TS 3.8.6, and renumbers it as SR 3.8.6.7.
Inaddition, 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 changeThis change moves SR 3.8.4.14 to TS 3.8.6 and renumbers it as SR 3.8.6.7.
In addition, theNote restriction for performing the SR in Mode 1, 2, 3, or 4, which only applies to the vitalbatteries, is being deleted.
The purpose of SR 3.8.4.14 is to verify that the battery capacity forboth the vital and DG batteries meet design requirements.
Therefore, consistent with therequirements of SR 3.0.1, these surveillances are moved to TS 3.8.6. The proposed SRcontains 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 inorder to determine the state-of-health of the safety-related batteries given the expected servicelife. The surveillance frequencies are appropriate given the condition of the battery, allowssufficient time for corrective actions to be taken, and is consistent with the safety significance ofsafety-related batteries.
The restriction for performing the test on the vital batteries is eliminated since WBN has a sparebattery 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 thenormal batteries.
Therefore, no restriction on performing this SR (new SR 3.8.6.7) duringModes 1, 2, 3, and 4 is required.
3.2 TS 3.8.5, DC Sources -ShutdownTVA proposes to revise TS 3.8.5 LCO Notes, Conditions, Required
: Actions, and SRs asdescribed below.3.2.1 LCO 3.8.5 LCO NotesThe 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 vitalchargers;
: 3. Spare DG Battery Chargers WA1, 1 B1, 2A1, and 2B1 may be substituted for required DGchargers; and4. The C-S DG and its associated DC electrical power subsystem may be substituted forany of the required DGs and their associated DC electrical power subsystem.
Technical Justification for TS 3.8.5 LCO Notes changeExisting Note 2 is renumbered Note 4. New Notes 2 and 3 allow substitution of the spare vitalbattery and DG battery chargers for the required battery chargers.
The spare battery chargersare fully qualified and appropriately sized to perform their design safety function as those beingE1-13 of 29 replaced.
The description of the chargers, both normal and spare (also identified as alternate) isprovided in Section 2.0 (Background) of this enclosure.
3.2.2 TS 3.8.5 Required Action A.2.4 and Condition BRequired Action A.2.4 is modified to clarify that the Required Action is specific to the vitalbattery subsystem and not the DG electrical power subsystem.
The proposed change adds theword "vital,"
such that the Required Action reads "...restore required vital DC electrical powersubsystems 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 powersubsystem inoperable.
Technical Justification for TS 3.8.5 Required Action A.2.4 and Condition B changeCurrent 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 actualCondition.
The Condition B addition ensures that proper actions are taken when more than oneDG DC electrical power subsystems are required by the LCO and more than one areinoperable.
The current Condition only applies to a single inoperability
-no Actions are providedwhen 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, itsassociated 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 3.8.5.1The proposed change would modify SR 3.8.5.1 to reflect the changes previously described inSection 3.1. Specifically, the SR numbers have been changed to reflect the deletion fromTechnical 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 changeSR 3.8.5.1 is modified to be consistent with the proposed changes to TS 3.8.4. RevisedSR 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 certainSRs, as allowed in the Note to the SR, identifies the same SRs as are in the current Note thatare remaining in TS 3.8.4.The proposed change meets 10 CFR 50.36 requirements for surveillances by ensuring that thenecessary quality of systems and components is maintained and that the LCOs will be met.El-14 of 29 3.3 TS 3.8.6, Battery Parameters TVA proposes to revise TS 3.8.6 LCO, Conditions, Required
: Actions, and SRs. As part ofthese changes, battery float current monitoring is replacing specific gravity monitoring and anew TS Battery Monitoring and Maintenance Program is being added into TS Chapter 5.3.3.1 TS 3.8.6 TitleThe proposed change revises the title of TS 3.8.6 from "Battery Cell Parameters" to "BatteryParameters."
Technical Justification for TS 3.8.6 Title changeThe 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 natureand will not result in new requirements or change operational restrictions or flexibility.
3.3.2 TS 3.8.6 LCOThe proposed change revises TS 3.8.6 LCO to delete the word "cell" and to require that thebattery 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 LCOstatement.
Technical Justification for TS 3.8.6 LCOThe change to delete the term "cell" is consistent with the change described in Section 3.3.1above. The revised TS 3.8.6 includes parameters that are not individual battery cellparameters.
The change to add the word "required" is consistent with TS 3.8.4 and TS 3.8.5, in thatLCO 3.8.4 Note 1 allows the alternate battery (Vital Battery V) to be used to meet theLCO requirements.
Thus, the word "required" is added for consistency when there are moreinstalled components than are required to meet the LCO.The change deleting the reference to Table 3.8.6-1 is consistent with changes described andjustified below in Section 3.3.4 below.Therefore, these changes are editorial in nature.3.3.3 TS 3.8.6 ACTIONS NoteThe proposed change deletes the term "bank" from the ACTIONS Note. Specifically, theACTIONS Note will be changed from "Separate Condition entry is allowed for each batterybank" to "Separate Condition entry is allowed for each battery."
Technical Justification for TS 3.8.6 ACTION Note changeThe change is editorial in nature, in that WBN Unit 1 does not have battery "banks" nor do theactual Conditions refer to battery banks. Therefore, deletion of the term "bank" brings theACTIONS Note into alignment with the actual (and revised)
Conditions.
EI-15 of 29 3.3.4 TS 3.8.6 Table 3.8.6-1The proposed change deletes Table 3.8.6-1, "Battery Cell Parameter Requirements" and movesthe 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 tolicensee-controlled documents.
Technical Justification for TS 3.8.6 Table 3.8.6-1 changesTS 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 innew 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 aand b) and the Required Actions associated with restoring the cell parameters to within theselimits (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 toplace this information in the licensee-controlled program.
The Category A and B values ofTS 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 restoredeficient 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 theregulatory requirements of 10 CFR 50.65. This relocation will continue to assure that thebattery is maintained at current levels of performance, and that operators appropriately focus onmonitoring the battery parameters for degradation.
TVA proposes relocating the Category C specific limiting values of TS Table 3.8.6-1 for thebattery electrolyte levels to the Battery Monitoring and Maintenance Program.
: However, newTS 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. TVAproposes relocating the electrolyte temperature and level criteria (i.e., the minimum established design limits) to the Battery Monitoring and Maintenance Program.
This program will becontrolled as required by new TS 5.7.2.21, and TVA commits to place this information in alicensee-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 provideTVA with added flexibility to monitor and control this limit at values directly related to thebattery's ability to perform its assumed function.
TVA also proposes relocating the Category C specific limiting values of TS Table 3.8.6-1 forspecific gravity to the Battery Monitoring and Maintenance Program.
: However, in lieu ofrelocating the specific
: gravity, TVA proposes to use float current monitoring to measure batterystate of charge. This method is currently allowed by Table 3.8.6-1 Note c for up to 31 daysfollowing 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, thebatteries are at least 98% recharged.
TVA therefore commits to maintain a 2% design marginto provide assurance that the batteries are fully charged when the above float current limits areEl-16 of 29 reached.
In addition, TVA commits to revise the UFSAR to provide a description of thiscapability.
For replacement batteries of a different model/size and/or manufacturer, float currentlimit 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 monitorfloat current under new SR 3.8.6.1 and SR 3.8.6.2 (which are described below inSection 3.3.12) will have the necessary accuracy and capability to measure electric currents inthe 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 theTS Battery Monitoring and Maintenance Program.3.3.5 TS 3.8.6 Actions A and CThe proposed change adds new TS 3.8.6 Actions A and C to address what is currently theCategory C limit for float voltage in TS Table 3.8.6-1.
Current TS 3.8.6 Action B requires thebattery to be immediately declared inoperable when this value is not met.Technical Justification for TS 3.8.6 Actions A and C changesTVA proposes deleting Action B, as it refers to the Category C limit for float voltage, and addingnew TS 3.8.6 Actions A and C to address what was formerly the Category C limit for floatvoltage 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 than2.07V. Actions A and C provide the Required Actions for the condition of a degraded batterycell. The Required Actions are to perform within 2 hours: (a) SR 3.8.4.1 or SR 3.8.4.2 -verifythe 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 eachbattery's float current is less than or equal to 2 amps for the vital batteries and less than 1 ampfor the DG batteries (Required Actions A.2 and C.2, respectivelyl).
The above actions ensurethat there is still sufficient capacity for the battery to perform its intended function.
Provided theabove actions are met, Required Actions A.3 and C.3 will allow continued operation for up to24 hours 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'sUFSAR provides reasonable assurance that the value will be appropriately maintained by TVAto accurately reflect the design of the plant.3.3.6 TS 3.8.6 Actions B and DThe 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 thecurrent 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 changeTVA proposes deleting Action B, as it refers to the category C limit on specific
: gravity, andadding new TS 3.8.6 Actions B and D to address battery state of charge. These new Actionsare applicable when one required vital battery (Action B) is found with float current greater than2 amps or one required DG battery (Action D) is found with float current greater than 1 amp. Afloat current of greater than 2 amps for the vital batteries and 1 amp for DG batteries providesindication that a partial discharge has occurred.
The Required Actions (Required Actions B.1E1-17 of 29 and D.1) are to verify within 2 hours that the battery terminal voltage is greater than or equal tothe 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 cellswith voltage less than 2.07V, Required Actions B.2 and D.2 require that within 12 hours thebattery be restored to its fully-charged condition (i.e., < 2 amps for the vital battery and < 1 ampfor the DG battery) from any discharge that might have occurred due to a temporary loss of thebattery 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 thebattery charger is operating in the current limit mode for 2 hours, it indicates that the battery hasbeen substantially discharged and likely cannot perform its required design functions.
In thiscase, new Condition H would be entered.
This Action requires the associated battery to beimmediately declared inoperable, which is consistent with current Action B.3.3.7 TS 3.8.6 Action EThe proposed change adds new TS 3.8.6 Action E to address the level of the electrolyte in acell. Current TS 3.8.6 Action A provides the actions when electrolyte level does not meet thecategory A and B limits, and requires verification the level is above the top of the plates within1 hour and to restore the level to within limits in 31 days.Technical Justification for TS 3.8.6 Action E changeTVA proposes adding new TS 3.8.6 Action E to address the electrolyte level in a cell. This newAction E is applicable when one required vital or DG battery is found with one or more cells withan electrolyte level less than the minimum established design limits. If the electrolyte level isabove 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 itsintended safety function and could be considered operable.
With the electrolyte level below thetop of the plates, there is a potential for dry-out and plate degradation.
New RequiredActions 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 hours (Required Action E. 1), ensure that the cause of the loss of the electrolyte level is not due to a leak in thebattery cell jar within 12 hours (Required Action E.2), and equalize and test the battery cells thathave been discovered with an electrolyte level below the top of the plates in accordance withthe 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. Inaddition, Required Action E.3 requires the battery electrolyte level to be restored to greater thanor equal to the minimum established design limits within 31 days.3.3.8 TS 3.8.6 Action FThe proposed change adds new TS 3.8.6 Action F which applies to a battery found with a pilotcell electrolyte temperature less than the minimum established design limit. Current TS 3.8.6Action B requires the battery to be immediately declared inoperable when a pilot cell electrolyte temperature is not within limits.EI-18 of 29 Technical Justification for TS 3.8.6 Action F changeTVA proposes adding new TS 3.8.6 Action F which applies to a battery found with a pilot cellelectrolyte 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 isapplicable 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.1requires the electrolyte pilot cell temperature to be restored to greater than or equal to theminimum established design limits within 12 hours. The TVA batteries are sized with correction margins to account for factors affecting performance that include temperature and aging andadequate battery design margins.
As a consequence, TVA commits to periodically monitorbattery 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 aseparate environmentally controlled area outside the engineered safety feature switchgear rooms. The temperature of the room containing the batteries is currently monitored at leastevery 12 hours during operator tours. If battery room temperature were to decrease belowadministrative limits, TVA will implement corrective measures to restore battery roomtemperature in accordance with plant procedures.
Historic data indicate that temperature deviation between cells in a given battery have notdeviated more than 30F between the highest and lowest temperature cell. This meetsIEEE 450-2002 recommendation that the maximum temperature deviation across the batterynot exceed a maximum of 50F.Based on these considerations and the fact that batteries have very large thermal inertia, it ishighly likely that a room temperature excursion would be corrected prior to the batteryelectrolyte reaching its maximum or minimum design temperature.
3.3.9 TS 3.8.6 Action GThe proposed change adds new TS 3.8.6 Action G to addresses the condition in which two ormore redundant batteries (i.e., two or more vital batteries or two or more DG batteries) havebattery parameters that are not within limits. Currently, TS 3.8.6 Action B requires a battery tobe immediately declared inoperable under this condition.
Technical Justification for TS 3.8.6 Action E changeTVA proposes adding new TS 3.8.6 Action G to address the condition in which more than onerequired vital or DG battery has battery parameters not within the limits specified in Conditions Athrough F. If this condition exists, there is not sufficient assurance that the batteries will becapable of performing their intended safety function.
With redundant batteries
: involved, loss offunction is possible for multiple systems that depend upon the batteries.
Proposed RequiredAction G.1 requires the affected battery parameters be restored to within limits within 2 hours.The 2-hour time period is consistent with similar LCOs established by the TS (i.e., TS 3.8.9Distribution Systems -Operating) and is reasonable considering the potential for loss of functionof components that depend on the batteries (e.g., AC vital bus subsystem(s),
electrical breakercontrol/position indication power). Accordingly, a relatively short duration is provided to resolvethe condition with minimum risk.E1-19 of 29 3.3.10 TS 3.8.6 Action HThe proposed change deletes existing Action B and replaces it with new Action H.Technical Justification for TS 3.8.6 Action B changeExisting Condition B describes three Conditions of battery cell parameter inoperability.
Theseconditions 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&deg;F for DG batteries; and3. One or more batteries with one or more battery cell parameters not within Category Cvalues.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 forbattery 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 Athrough 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 maximumexpected load requirements.
New Condition H also addresses the case where one requiredvital battery or one required DG battery with one or more battery cells float voltage less than2.07V and a float current greater than 2 amps for the vital batteries or greater than 1 amp for theDG batteries.
Since battery capacity may be incapable of performing the intended designfunction, new Required Action H. 1 requires the associated battery to be immediately declaredinoperable.
3.3.11 SR 3.8.6.1, SR 3.8.6.2, and SR 3.8.6.3The 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 meetTable 3.8.6-1 Category B limits and c) SR 3.8.6.3 to verify average electrolyte temperature ofrepresentative cells is > 60&deg;F for vital batteries and > 50&deg;F for the DG batteries.
Technical Justification for SR 3.8.6.1, SR 3.8.6.2, and SR 3.8.6.3 changeThe elimination of existing SR 3.8.6.1 and SR 3.8.6.2 is consistent with the elimination ofTS 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 withrestoring 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 extendedbattery 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 greaterthan or equal to 2.13V is a maintenance limit; and (3) specific gravity measurement criteria arebeing 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 attheir current level, and that actions to restore deficient values will be implemented according toTVA corrective action program.E1-20 of 29 Furthermore, the battery and its preventive maintenance and monitoring program are under theregulatory requirements of 10 CFR 50.65. This relocation will continue to assure that the batteryis maintained at current levels of performance, and that operators appropriately focus onmonitoring 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 BatteryMonitoring 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 sectionsprovide assurance that battery quality and operability will continue to be maintained.
3.3.12 New SR 3.8.6.1 and SR 3.8.6.2The 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 changeTVA proposes adding new SR 3.8.6.1 and SR 3.8.6.2, which require verification every 7 daysthat the float current for each vital battery is less than or equal to 2 amps and that each DGbattery is less than or equal to 1 amp. In addition, a Note states that the limit is not required tobe met when the associated
.battery terminal voltage is less than the minimum established floatvoltage of SR 3.8.4.1 (for the vital batteries) and SR 3.8.4.2 (for the DG batteries).
The purposeof the SRs is to determine the state of charge of the battery.
Float charge is the condition inwhich the battery charger is supplying the continuous small amount of current (i.e., less than orequal 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 chargedstate. The float current requirements are based on the float current indicative of a chargedbattery.
As stated above in Section 3.3.4 above, the use of float current to determine the stateof charge of the battery is consistent with the battery manufacturer recommendations.
The Noteis acceptable since when the float voltage is not maintained, the Required Actions of TS 3.8.4Action A or E are being taken, which provide the appropriate and necessary verifications of thebattery condition.
3.3.13 New SR 3.8.6.3The proposed change adds new SR 3.8.6.3.Technical Justification for New SR 3.8.6.3 changeTVA proposes adding new SR 3.8.6.3, which requires verification every 31 days that the floatvoltage of pilot cells for the vital and DG batteries is greater than or equal to 2.07V. This voltagelevel represents the minimum acceptable voltage for operability.
The Battery Monitoring andMaintenance Program in new TS Section 5.7.2.21 includes actions to restore battery cells withfloat voltage less than 2.13V and actions to verify that the remaining cells are greater than orequal to 2.07V when a cell or cells have been found to be less than 2.13V. The 31 dayfrequency provides reasonable assurance that the battery can perform its intended safetyE1-21 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 3.8.6.4The proposed change adds new SR 3.8.6.4.Technical Justification for New SR 3.8.6.4 changeTVA proposes adding new SR 3.8.6.4, which requires verification every 31 days that theelectrolyte level of each individual cell in the vital and DG battery is greater than or equal to theminimum established design limits. Operation of the batteries at electrolyte levels greater thanthe minimum established design limit ensures that the battery plates do not suffer physicaldamage and continue to maintain adequate electron transfer capability.
TVA also proposes relocating the specific limiting values for the battery electrolyte level that arein 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 greaterthan 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 directlyrelated to the battery's ability to perform its required safety function.
Incorporating the minimumestablished design level limit into the plant's UFSAR provides reasonable assurance that thevalue will be appropriately maintained to accurately reflect the design of the plant.3.3.15 New SR 3.8.6.5The proposed change adds new SR 3.8.6.5.Technical Justification for New SR 3.8.6.5 changeTVA proposes adding new SR 3.8.6.5, which requires verification every 31 days that thetemperature of each vital and DG battery pilot cell is greater than or equal to the minimumestablished design limits. This SR replaces existing SR 3.8.6.3, which requires verifying theaverage (versus pilot cell) electrolyte temperature every 92 days. Batteries have very largethermal 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 batteryroom temperatures.
As a result, the pilot cell temperature is a valid representation of thetemperature 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 theelectrolyte temperature to be greater than or equal to the "minimum established design limits."Depending on the available excess capacity of the associated
: battery, the minimumtemperature necessary to support operability of the battery can vary. Relocation to the BatteryMonitoring and Maintenance Program will allow flexibility to monitor and control this limit atvalues directly related to the battery ability to perform its intended function.
Incorporating theminimum 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 theplant.E1-22 of 29 3.3.16 New SR 3.8.6.6The proposed change adds new SR 3.8.6.6.Technical Justification for New SR 3.8.6.6 changeTVA proposes adding new SR 3.8.6.6, which requires verification every 92 days that the floatvoltage of all connected cells for the vital and DG batteries is greater than or equal to 2.07 V percell (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 floatvoltage 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.
Floatvoltages in this range or less, but greater than 2.07 Vpc, are addressed in the BatteryMonitoring and Maintenance Program.
Furthermore, the Battery Monitoring and Maintenance Program includes actions to restore battery cells with float voltage less than 2.13 Vpc andactions to verify that the remaining cells are greater than or equal to 2.07 Vpc when a cell orcells have been found to be less than 2.13 Vpc. The 2.07 Vpc limit reflects the Operability limitfor the batteries.
With all battery cells above 2.07 Vpc, there is adequate assurance that theterminal voltage is at an acceptable threshold for establishing battery operability.
3.3.17 New SR 3.8.6.7The proposed change moves the battery capacity test from existing SR 3.8.4.14 to newSR 3.8.6.7.Technical Justification for New SR 3.8.6.7 changeSee Section 3.1.9 above for the technical justification.
3.4 TS 5.7.2.21, Battery Monitoring and Maintenance ProgramThe proposed change would add a new Battery Monitoring and Maintenance Programrequirements as TS 5.7.2.21.
Technical Justification for new TS 5.7.2.21TVA proposes new TS 5.7.2.21, "Battery Monitoring and Maintenance Program,"
to read asfollows.Battery Monitoring and Maintenance ProgramThis program provides controls for battery restoration and maintenance.
The program shall be inaccordance with the IEEE Std. 450-2002, "IEEE Recommended Practice for Maintenance,
: Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications,"
asendorsed by RG 1.129, Revision 2 (RG), with RG exceptions and program provisions asidentified 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 thisprogram.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 bebased on the lowest voltage cell in the battery."
: 4. In RG 1.129, Regulatory Position 3, Subsection 5.4.1, "State of Charge Indicator,"
thefollowing statements in paragraph (d) may be omitted:
'When it has been recorded thatthe charging current has stabilized at the charging voltage for three consecutive hourlymeasurements, the battery is near full charge. These measurements shall be madeafter the initially high charging current decreases sharply and the battery voltage rises toapproach 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 > 2.13Vwhen 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 levelbelow the top of the plates;4. Limits on average electrolyte temperature, battery connection resistance, and batteryterminal voltage; and5. 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, celltemperature, float voltage, connection resistance, and physical condition) will be relocated tothis program.
The Battery Maintenance and Monitoring Program will ensure that the abovebattery parameters will be maintained and that actions will be implemented should the batteryparameter(s) not be met.The TS 5.7.2.21 Battery Monitoring and Maintenance Program provides assurance that thebattery parameters will be monitored and controlled in accordance with the program, and thatactions 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 ModelSafety Evaluation provided for TSTF-500 as the basis for this change, TVA reviewedE1-24 of 29 Section 2.2 of the model application and has included all applicable information requested bythe NRC in this section.
Furthermore, Section 2.2 of the model application included otherverifications and requested changes to the UFSAR. TVA is providing commitments to ensurethe requested verifications and UFSAR changes are made prior to implementing the changesrequested in this License Amendment Request (LAR). The list of commitments is provided inEnclosure 2 to this LAR.The TVA process governing the processing and submittal of TSs changes and LicenseAmendment Requests requires that the appropriate organizations (e.g., Operations,
: Training, Engineering, Maintenance, Chemistry, Radiation Protection, and Work Control) identify thedocuments that are affected by each proposed change to the TSs and Operating Licenses.
Among the items that are considered are training, plant modifications, procedures, specialimplementation constraints, design documents, surveillance instructions associated withTSs SRs, Technical Requirements Manual, TSs Bases, and UFSAR. The process requires thatprocedures and design document changes necessary to support TSs Operability are approvedprior to implementation of the license amendment.
The process also provides assurance thatthe 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 powersystems at WBN which are designed to comply with the following applicable regulations andrequirements:
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 PlantProtection Systems";
RG 1.63, Revision 2, "Electric Penetration Assemblies in Containment Structures forWater-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 NuclearPower 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 forNuclear Power Plants";RG 1.129, Revision 1, "Maintenance,
: Testing, and Replacement of Large Lead StorageBatteries for Nuclear Power Plants";RG 1.153, Revision 0, "Criteria for Power, Instrumentation, and Control Portions of SafetySystems";
RG 1.155, Revision 1, "Station Blackout";
andRG 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 theapplicable regulations and requirements.
===4.2 Precedent===
An acceptance review in accordance with LIC-1 09 was issued for the following plants: ArkansasNuclear One, Units 1 and 2, and Palo Verde, Units 1, 2 and 3. Both sites submitted TS changesbased on the model application contained in TSTF-500.
The proposed TS changes for thoseplants were based on the DC electrical power distribution model referenced in the Bases forNUREG-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 1DC electrical power distribution system is significantly different from that referenced in themodel application, TVA is submitting a stand-alone LAR that provides the technical andregulatory 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 "BatteryMonitoring 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 cellsas 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 notinvolve a significant hazards consideration.
TVA's conclusion is based on its evaluation inaccordance 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 orconsequences of any accident previously evaluated?
Response:
No.The proposed changes restructure the Technical Specifications (TS) for the directcurrent (DC) electrical power system and are consistent with Technical Specifications Task Force (TSTF) change TSTF-360, Revision 1 and TSTF-500, Revision
: 2. Theproposed changes modify TS Actions relating to battery and battery chargerinoperability.
The DC electrical power system, including associated battery chargers, isnot an initiator of any accident sequence analyzed in the Updated Final Safety AnalysisReport (UFSAR).
Rather, the DC electrical power system supports equipment used tomitigate accidents.
The proposed changes to restructure TS and change surveillances for batteries and chargers to incorporate the updates included in TSTF-360, Revision 1as updated by TSTF-500, Revision 2, will maintain the same level of equipment performance required for mitigating accidents assumed in the UFSAR. Operation inaccordance with the proposed TS would ensure that the DC electrical power system iscapable of performing its specified safety function as described in the UFSAR.Therefore, the mitigating functions supported by the DC electrical power system willcontinue to provide the protection assumed by the analysis.
The relocation of preventive maintenance surveillances, and certain operating limits and actions, to a licenseecontrolled Battery Monitoring and Maintenance Program will not challenge the ability ofthe DC electrical power system to perform its design function.
Appropriate monitoring and maintenance that are consistent with industry standards will continue to beperformed.
In addition, the DC electrical power system is within the scope of10 CFR 50.65, "Requirements for monitoring the effectiveness of maintenance atnuclear 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 asdescribed in the UFSAR will not be affected by the proposed changes.
Therefore, theconsequences of previously analyzed accidents will not increase by implementing thesechanges.Therefore, the proposed amendment does not involve a significant increase in theprobability or consequences of an accident previously evaluated.
: 2. Does the proposed amendment create the possibility of a new or different kind ofaccident from any accident previously evaluated?
Response:
NoThe 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 powersystem supports equipment used to mitigate accidents.
The proposed changes torestructure 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, willmaintain the same level of equipment performance required for mitigating accidents assumed in the UFSAR. Administrative and mechanical controls are in place to ensureE1-27of29
.
the design and operation of the DC systems continues to meet the plant design basisdescribed 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 ofsafety?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 bemaintained in accordance with the plant-specific design bases as a result of theproposed changes.
The proposed changes will not adversely affect operation of plantequipment.
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 powerto safety-related loads in accordance with analysis assumptions.
TS changes made tobe 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 andthe current TSs.Therefore, the proposed changes do not involve a significant reduction in a margin ofsafety.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 proposedmanner, (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 securityor to the health and safety of the public.5.0 ENVIRONMENTAL CONSIDERATION A review has determined that the proposed amendment would change a requirement withrespect to installation or use of a facility component located within the restricted area, as definedin 10 CFR Part 20, and would change an inspection or surveillance requirement.
: However, theproposed 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 releasedoffsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion setforth in 10 CFR 51.22(c)(9).
Therefore, pursuant to 10 CFR 51.22(b),
no environmental impactstatement or environmental assessment need be prepared in connection with the proposedamendment.
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, andReplacement of Vented Lead-Acid Batteries for Stationary Applications,"
The Institute ofElectrical 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 IProposed WBN Unit I TS Changes (Markups)
Al-1 DC Sources -Operating 3.8.43.8 ELECTRICAL POWER SYSTEMS3.8.4 DC Sources -Operating LCO 3.8.4Four channels of vital DC and four Diesel Generator (DG) DC electrical powersubsystems 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 forrequired Vital chargers.
: 3. Spare DG Chargers 1A1, 1B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
: 24. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystem.
APPLICABILITY:
MODES 1, 2, 3, and 4.ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Restore vital battery terminal 2 hourscharger inoperable, voltage to greater than orequal to the minimumestablished float voltage.ANDA.2 Verify vital battery float Once per 12 hourscurrent < 2 amps.ANDA.3 Restore vital battery charger 72 hoursto OPERABLE status.B. One required vital battery B.1 Restore vital battery to 2 hoursinoperable.
OPERABLE status.AC. One required vital DC AC.1 Restore vital DC eleetFieal-2 hours powerF sbsystemchannel tosub6ysteinchannel OPERABLE status.inoperable for reasonsother than Condition A or B.BD. Required Action and BD.1 Be in MODE 3. 6 hoursassociated Completion ANDTime of Condition A, B or Cnot met. 9D.2 Be in MODE 5. 36 hours(continued)
Watts Bar-Unit 13.8-24 DC Sources -Operating 3.8.4ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIMEE. One required DG battery E.1 Restore DG battery terminal 2 hourscharger inoperable, voltage to greater than or equalto the minimum established float voltage.ANDE.2 Verify DG battery float current Once per 12 hours< 1 amp.ANDE.3 Restore DG battery charger to 72 hoursOPERABLE status.F. One required DG battery F.1 Restore DG battery to 2 hoursinoperable.
OPERABLE status.GG. One required DG DC GG.1 Restore DG DC electrical 2 hourselectrical power subsystem power subsystem toinoperable 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, orG not met.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify vital battery terminal voltage is greater than or 7 daysequal to the minimum established-'
128 V (132 V forvital batteiy-V-Gn float ehargevoltage.
SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 daysequal to the minimum established
--1-24-V-enfloat
-GhaFevoltage.
SR 3.8.4.3 Verify for the vital batteries that the alternate feeder 7 daysbreakers to each required battery charger are open.SR 3.8.4.4 Verify correct breaker alignment and indicated power 7 daysavailability for each DG 125V DC distribution paneland associated battery charger.(continued)
Watts Bar-Unit 13.8-25 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.84.5 Vori.fy no visible corroslon at term!ials and connectors for the "ital batteiors.
QRVerify for the vital batteries is_ 80 E 6 ohm for inter col connectiGons,
< 50 E 6 ohmfor inter rack connetons, 120 E 6 ohm-fo;r intrtierfrntr rconnect
,and -50 E 68 oh for teminfalGGAReGtGR Verify no Visibble corroion69-at ter~minals and coennectors-92-daySfor the; DG batteries.
ORVerify connection resistanco for the DG batteries ist 80 E 6 ohm for inter Goil cnnection, f 50=E 6 ohm3,fnor inter tier cnnections, and 50 Em 6 ohm forterminal connections.
SR 3.9.4.7-Verify batte~' cells, coil' plates, and racks Show no 1: mvisual idctOn f physical damage or abnormalSR~&4Remoeve vfisfible termninal corrosion and verify batter; 1-2 menthscGell to cell and teirminOa.l cnecin are cAPted wiethantR~iw cor.Arosion m~aterial.
(continued Watts Bar-Unit 13.8-26 DC Sources -Operating 3.8.4SURVEILLANCE FREQUENCY Verif.. connection rosistAnco for the vital batteries is 12 menths4 80 E-6 ohmfrA Wno ce911 connotions
-50 E 6R forFinter rack connections, 120 E 6R ohm forintr tier-connections, aRnd  50 E 6 ohm for termin.al G0RR9GtGA
&R 2_84WQ Vorify connec-tioresitac for the DG batteries 6 1-2 menthi<- 8_0 6 hRm- fo-r iRter cellII connections,
-50 E 6 ohmfmor inter tier co Gnnecti8nS, and _' -50 EF -6 ohm forterminal connections.
SR 3.8.4.14-5 NOTEThio Sur-, eillnce is normally not peF....,d inMODE 1, 2, 3, o-r 4. HoWeer, cedit mRay be takenfor unplanned events that satisfy this SR.Verify each vital battery charger is Gapable ef 18 monthsrecharging its associated batter';
from a srioocapacity discharge test while supplying normallead6supplies
> 200 amps at greater than or equal tothe minimum established float voltage for > 4 hours.ORVerify each vital battery charger 0s-eapable-of operating for >_ 4 ho-urs- at courrent limnit 2:20 :250aa4Wan recharge the battery to the fully chargedstate within 24 hours while supplying the largestcombined demands of the various continuous steadystate loads, after a battery discharge to the boundingdesign basis event discharge state.(continued)
Watts Bar-Unit 13.8-27Amendment 54 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.4.426 NOTECredit may be taken for Uplannod
-vents that satisfythis SR.Verify each diesel-geRe.,ateDG battery charger 18 monthssupplies
> 20 amps at greater than or equal to theminimum established float voltage for > 4 hoursis-cGipable Of FeGaiig!RiyI its GGOiat JJLtte tFE)ri ase -c orcpacity dischargo test While supplying eFFnal .ORVerify each DG battery charger can recharge thebattery to the fully charged state within 24 hours whilesupplying the largest combined demands of thevarious continuous steady state loads, after a batterydischarge to the bounding design basis eventdischarge state.SR 3.8.4.47
-----------------------
NOTES----------------
: 1. The modified performance discharge test inSR 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 betaken for unplanned events that satisfy this SR.Verify battery capacity is adequate to supply, and 18 monthsmaintain in OPERABLE status, the requiredemergency loads and any connected nonsafety loadsfor the design duty cycle when subjected to a batteryservice test.Watts Bar-Unit 13.8-28Amendment 12 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.4.!4 NOTEST-hi6 Survoillance8 i ot po~formFed in MODE 1, 2, 3,or 4 for required vita' batteries.
Credit may betakon for unplanned eVRnts that satisfy this SR.Vorify batter' capacity is ; 80% of themanufactuor's 6-fnectuhs r-ating when subjoctod to a po4ormaRce discharge torst-or moifed oformanco discharge test- AND12 months whenbatte,-y rhes w6hdogradation Or hasreac hed 85% expected lifo wth-capacity 4100% OfmfanRufacturor's ratingANQ24 meonths;i.
whenbatter; has reached85% of expocted lifowith capacit"
&#xfd; 100%of mnanufacturer's Watts Bar-Unit 13.8-29Amendment 12 DC Sources-Shutdown 3.8.53.8 ELECTRICAL POWER SYSTEMS3.8.5 DC Sources -ShutdownLCO 3.8.5Vital DC and Diesel Generator (DG) DC electrical power subsystems shall beOPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems -Shutdown" and to support theDiesel 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.Spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for requiredvital chargers.
: 3. Spare DG chargers 1Al, 1 B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
: 24. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystems.
APPLICABILITY:
MODES 5 and 6,During movement of irradiated fuel assemblies.
ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One or more required A.1.1 Declare affected required Immediately vital DC electrical power feature(s) inoperable.
subsystems inoperable.
ORA.2.1 Suspend CORE Immediately ALTERATIONS.
ANDA.2.2 Suspend movement of Immediately irradiated fuel assemblies.
(continued)
Watts Bar-Unit I3.8-30 DC Sources-Shutdown 3.8.5ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. (continued)
ANDA.2.3 Initiate action to suspend Immediately operations involving positivereactivity additions.
ANDA.2.4 Initiate action to restore Immediately required vital DC electrical power subsystems toOPERABLE status.B. One or more required DG B.1 Declare associated DG Immediately DC electrical power inoperable subsystems inoperable.
Watts Bar-Unit 13.8-31 DC Sources-Shutdown 3.8.5SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.5.1-----------------
NOTE ----------------
The following SRs are not required to beperformed:
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, thefollowing SRs are applicable:
In accordance withapplicable SRsSR 3.8.4.1SR 3.8.4.2SR 3.8.4.3SR 3.8.4.4SR 3.8.4.5SR 3.8.4.6SR 3.8.4.7SR 3.8.4.9SR 3.9.4!.!S R 3.9..1SR 384.14Watts Bar-Unit 13.8-32 Battery GeU-Parameters 3.8.63.8 ELECTRICAL POWER SYSTEMS3.8.6 Battery Gell-Parameters ILCO 3.8.6Battery Gell-parameters for required 125 V vital batteries and 125 V dieselgenerator (DG) batteries shall be within the limits of Table 3.6.4 1.When associated DC electrical power subsystems and DGs are required to beOPERABLE.
APPLICABILITY:
ACTIONS----------------------------
NOTE-Separate Condition entry is allowed for each battery-baRk.
CONDITION REQUIRED ACTION COMPLETION TIMEA. Onie or moroe bhattorioc with A. I Vorify pilot c8l16 oloctrolyto 8eone Or moroe batter,'
coil level -and- float voltage mooetparametere not Within Table 3.8.69 1Catogor,'
CCatogor,'
A or B lim~itS.At4PA.2 Verify battery cel!
:24-he-wmnoot Table 3-8.65 1 Categor C(nnANDtheeaftef ANDA.3 Rectoro batter,'
cell 3-1 daysparameterc to Category Aand liits oaf Table 3861(continued)
Watts Bar-Unit 13.8-33 Battery GeII-Parameters 3.8.6ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIMEB A.Rouirod Action and I13 Declare associatod battery Immediately associated Completion iniepeFable.
Timo of Condition A notOno or mrenr- bhatteries withaVorage oloctrolye temper1ture of therepresentative cells 4-0 'F-for vital batterIes and -502Pfor DG ba4tteres OnA or more batteries; withone or mo-re battwGerol!
parametes net WithiCategory 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 7udaedCategory A lmts(continued)
Wafts Bar-Unit 13.8-34 Battery Ge4-Parameters 3.8.6Insert 1 -TS 3.8.6 ActionsACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Perform SR 3.8.4.1.
2 hourswith one or more batterycells float voltage < 2.07 V. ANDA.2 Perform SR 3.8.6.1.
2 hoursANDA.3 Restore affected cell float 24 hoursvoltage > 2.07 V.B. One required vital battery B.1 Perform SR 3.8.4.1.
2 hourswith float current > 2 amps.ANDB.2 Restore vital battery float 12 hourscurrent to < 2 amps.C. One required DG battery C.1 Perform SR 3.8.4.2.
2 hourswith one or more batterycells float voltage < 2.07 V. AND 2 hoursC.2 Perform SR 3.8.6.2.
24 hoursANDC.3 Restore affected cell floatvoltaqe > 2.07 V.DD.One required DG batterywith float current > 1 amp.D._1 Perform SR 3.8.4.2.2 hours12 hoursANDD.2 Restore DG battery floatcurrent to -< 1 amp.E. One required battery -------------------
NOTE -----------
with one or more cells with Required Actions E.1 and E.2 are onlyelectrolyte level less than applicable if electrolyte level was belowminimum established the top of plates.design limits.E.1 Restore electrolyte level to 8 hoursabove top of plates.ANDWatts Bar-Unit 1Inserts for Page 3.8-34 Battery GeN-Parameters 3.8.6CONDITION REQUIRED ACTION COMPLETION TIMEE.2 Verify no evidence of leakage.
12 hoursANDE.3 Restore electrolyte level to 31 daysgreater than or equal tominimum established designlimits.F. One required battery F.1 Restore battery pilot cell 12 hourswith Pilot cell electrolyte temperature to greater than ortemperature 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 hoursbatteries with battery within limits.parameters not within limits.ORMore than one reguired DGbatteries with batteryparameters 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.OROne required vital batterywith one or more batterycells float voltage < 2.07 Vand float current > 2 amps.OROne required DG batterywith one or more batterycells float voltage < 2.07Vand float current>
1 amp. IIWatts Bar-Unit 1Inserts for Page 3.8-34 Battery Gell-Parameters 3.8.6SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.6.2 Verify batteyr.
col pa.am.oto..
moo.t Table 3.8.6 1Category B limis 92 daysAND'GGe w:thin 21 hoursafe-a bttefyL
-110 I forvital battories (11 3.5V for vital battery V)or 106.5 V for 1DGratte4ues ANDOnce mithin :24 hoursovercharge
~150 Vfopr i~tal battorebattery V) or 115 VSR 3.8.6.3 Verify average eloctroTte temperature of 92 daysrepresentative cells is  60 OF for vital batteries and50&deg;F for the PG battries.j
[Replace Surveillance Requirements with Insert 2 (TS 3.8.6 SRs).1Watts Bar-Unit 13.8-35 Battery GeU-Parameters 3.8.6Insert 2 -TS 3.8.6 SRsSURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 ------------------------
NOTE ----------------
Not required to be met when vital battery terminalvoltage is less than the minimum established floatvolta-ge of SR 3.8.4.1.Verify each vital battery float current is < 2 amps. 7 daysSR 3.8.6.2 ------------------------
NOTE----------------
Not required to be met when DG battery terminalvoltage is less than the minimum established floatvoltage of SR 3.8.4.2.Verify each DG battery float current is < 1 amp. 7 daysSR 3.8.6.3 Verify each required vital and DG battery pilot cell 31 daysfloat voltage is > 2.07 V.SR 3.8.6.4 Verify each required vital and DG battery connected 31 dayscell electrolyte level is greater than or equal tominimum established design limits.SR 3.8.6.5 Verify each required vital and DG battery pilot cell 31 daystemperature is greater than or equal to minimumestablished design limits.SR 3.8.6.6 Verify each required vital and DG battery connected 92 dayscell float voltage is -> 2.07 V.Watts Bar-Unit IInserts for Page 3.8-35 Battery Gell-Parameters 3.8.6SURVEILLANCE FREQUENCY SR 3.8.6.7 -------------------------
NOTE ----------------
Credit may be taken for unplanned events thatsatisfy this SR.Verify battery capacity is > 80% of the manufacturer's 60 monthsrating when subiected to a performance discharge test or a modified performance discharge test. AND12 months whenbattery showsdegradation, or hasreached 85% of theexpected life withcapacity
< 100% ofmanufacturer's ratingAND24 months whenbattery has reached85% of the expectedlife with capacity
>100% ofmanufacturer's ratingWatts Bar-Unit 1Inserts for Page 3.8-35 Battery 3.8.6Table 3.8.6 1 (page 1 of !)
C'II PDammetr irimentsCAT-EORY A_: CATEGORY B: CATEGORPARAME LIMITS FOR EACH LIMITS FOR EACH ALLOWABLE LMITDESIGNATED PILOT CELL 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 level4indicatioR nmark (a) indication mark (a)Fleat Veltage _2-.- .2..V .>2.074Specific Gravity (b)(c) -1.200 1.1-95 hnet mror than 0.0:20beloW average of allAND connected coiAve~age of al ANDconnected cellsAverage of agWconnected cells(a) It it aceptable f4or the 9electrole level to tempo*rarly increase above the specified maxI mIm levelduring equalizing charges provided it is not evwflowing.
(b) Corrected far electrolyte temperature and level. Level correction is not required,
: however, whenbatter; charging 6 e- 2 amps when on float charge for Vital batteries, and- -4 1..0 amp for DGbatteres.
(G) A batter: chargingI current of e- 2 amps when on float charae for vital batteries6
-and -41.0 amoR for& IDG batterfies is acceptable for mneeting specific gravity limits. followineg a batter,'
: recharge, for amaximum 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 Drier to expiratien of the 31 davaiiewa4efRf r .... .r ...............
....Watts Bar-Unit I3.8-36 Procedures, Programs and Manuals5.75.7 Procedures,
: Programs, and Manuals5.7.2.21 Battery Monitoring and Maintenance Pro-gramThis Pro-gram provides controls for battery restoration and maintenance.
The programshall be in accordance with IEEE Standard (Std) 450-2002, "IEEE Recommended Practice for Maintenance,
: Testing, and Replacement of Vented Lead-Acid Batteries forStationary Applications,"
as endorsed by Regulatory Guide 1.129, Revision 2 (RG), withRG 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 afterconducting discharge tests.2. RG 1.129, Regulatory Position 1, Subsection 2, "References,"
is notapplicable 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 thebattery."
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 currenthas stabilized at the charging voltage for three consecutive hourlymeasurements, the battery is near full charge. These measurements shall be made after the initially high charging current decreases sharplyand 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 ofeach 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 batterycells is -2.13V when the float voltage of a battery cell has been found tobe < 2.13V:3. Actions to equalize and test battery cells that had been discovered withelectrolyte level below the top of the plates:4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and5. A requirement to obtain specific gravity readings of all cells at eachdischar-ge test, consistent with manufacturer recommendations.
Watts Bar-Unit 15.0-25b ATTACHMENT 2Proposed WBN Unit I Bases Page Changes (Markup)(For Information Only)A2-1 DC Sources-Operating B 3.8.4B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.4 DC Sources -Operating BASESBACKGROUND The station DC electrical power system provides the AC emergency powersystem with control power. It also provides both motive and control power toselected safety related equipment and preferred AC vital bus power (viainverters).
As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1),
the DCelectrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a singlefailure.
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 safetyfunction is to provide control power for engineered safety features equipment, emergency
: lighting, vital inverters, and other safety-related DC poweredequipment for the entire unit. The system capacity is sufficient to supply theseloads and any connected nonsafety loads during normal operation and to permitsafe 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 asingle 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 areassociated with Train B) and consists of four lead-acid-calcium batteries, eightbattery 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 allother channels so that a single failure in one channel will not cause a failure inanother channel.
Each channel consists of a battery charger which suppliesnormal DC power, a battery for emergency DC power, and a battery board whichfacilitates load grouping and provides circuit protection.
These four channels areused to provide emergency power to the 120V AC vital power system whichfurnishes 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 andalso have manual access to a spare (backup) charger for use upon loss of thenormal charger.(continued)
Watts Bar-Unit 1B 3.8-54Revision 105 DC Sources-Operating B 3.8.4BASESBACKGROUND 125V Vital DC Electrical Power Subsystem (continued)
Additionally, battery boards I, II, Ill, and IV have manual access to the fifth vitalbattery system. The fifth 125V DC Vital Battery System is intended to serve as areplacement 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 ofoperation.
Each of the vital DC electrical power subsystems provide the control power for itsassociated Class 1 E AC power load group, 6.9 kV switchgear, and 480V loadcenters.
The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, theypower the emergency DC lighting system.The vital DC power distribution system is described in more detail in Bases forLCO 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 loadcontinuously for at least 4 hours in the event of a loss of all AC power (stationblackout) without an accident or for 30 minutes with an accident considering asingle failure.
Load shedding of non-required loads will be performed to achievethe required coping duration for station blackout conditions.
Each 125V DC vital battery is separately housed in a ventilated room apart fromits charger and distribution
: centers, except for Vital Battery V. Each subsystem is located in an area separated physically and electrically from the othersubsystem to ensure that a single failure in one subsystem does not cause afailure in a redundant subsystem.
There is no sharing between redundant Class1 E subsystems, such as batteries, battery chargers, or distribution panels.The batteries for the vital DC electrical power subsystems are sized to producerequired capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the100% design demand. The voltage limit is 2.13 V per cell, whiGh correspends toa total minimum voltage output of ! 29V por batteFry (1232 for Vital Batter; V). Thecriteria 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 specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital battery) the total minimum outputvoltage is 124V and for a 62 cell battery (5tI vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or discharging.
Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further charginqper manufacturer's instructions.
Optimal long term performance
: however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadeguate over-potential, which limits the formation of lead sulfate and selfdischarge.
(continued)
Watts Bar-Unit 1B 3.8-55 DC Sources-Operating B 3.8.4BASESBACKGROUND 125V Vital DC Electrical Power Subsystem (continued)
Each Vital DC electrical power subsystem has ample power output capacity forthe steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.
Each batterycharger also has sufficient capacity to restore the battery bank from the designminimum charge to its fully charged state within 12 hours (with accident loadsbeing supplied) following a 30 minute AC power outage and in approximately 36hours (while supplying normal steady state loads following a 2 hour AC poweroutage),
(Ref.6).The battery charger is normally in the float-charge mode. Float-charge is thecondition in which the charger is supplying the connected loads and the batterycells are receiving adequate current to optimally charge the battery.
This assuresthe internal losses of a battery are overcome and the battery is maintained in afully charged state.When desired, the charger can be placed in the equalize mode. The equalizemode is at a higher voltage than the float mode and charging current iscorrespondingly higher. The battery charger is operated in the equalize modeafter a battery discharge or for routine maintenance.
Following a batterydischarge, the battery recharge characteristic accepts current at the current limitof the battery charger (if the discharge was significant, e.g., following a batteryservice test) until the battery terminal voltage approaches the charger voltagesetpoint.
Charging current then reduces exponentially during the remainder ofthe rechar-ge cycle. Lead calcium batteries have recharge efficiencies of greaterthan 91%, so once at least 110% of the ampere-hours discharged have beenreturned, the battery capacity would be restored to the same condition as it wasprior to the discharge.
This can be monitored by direct observation of theexponentially 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 andfield-flash circuits have power supplied from their respective 125V distribution panel. The normal supply of DC current is from the associated charger.
Thebattery provides control and field-flash power when the charger is unavailable.
The charger supplies the normal DC loads, maintains the battery in a fullycharged condition, and recharges (480V AC available) the battery whilesupplying the required loads regardless of the status of the unit. The batteries are physically and electrically independent.
The battery has sufficient capacitywhen fully charged to supply required loads for a minimum of 30 minutesfollowing a loss of normal power. Each battery is normally required to supplyloads during the time interval between loss of normal feed to its charger and thereceipt of emergency power to the charger from its respective DG.(continued)
Watts Bar-Unit 1B 3.8-56Revis ion 113 DC Sources-Operating B 3.8.4BASESAPPLICABLE SAFETY ANALYSESThe initial conditions of Design Basis Accident (DBA) andtransient 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 DCelectrical power for the emergency auxiliaries, and control and switching duringall power for the emergency auxiliaries, and control and switching during allMODES 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 theplant. This includes maintaining the DC sources OPERABLE during accidentconditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.The DC sources satisfy Criterion 3 of the NRC Policy Statement.
LCOFour 125V vital DC electrical power subsystems, each vital subsystem channelconsisting 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 eachconsisting of a battery, a dual battery charger assembly, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE toensure the availability of the required power to shut down the reactor andmaintain it in a safe condition after an anticipated operational occurrence (AOO)or a postulated DBA. Loss of any DC electrical power subsystem does notprevent the minimum safety function from being performed (Ref. 4).An OPERABLE vital DC electrical power subsystem requires all requiredbatteries and respective chargers to be operating and connected to theassociated DC buses.The LCO is modified by twefour Notes. Note 1 indicates that Vital Battery V maybe substituted for any of the required vital batteries.
: However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.
Note2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted forrequired vital charqers.
Note 3 indicate that spare DG chargers 1Al, 1B1, 2A1, or2B1 may be substituted for required DG chargers.
: However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.
Note 24 has boon addod toindicates that the C-S DG and itsassociated DC subsystem may be substituted for any of the required DGs.However, the C-S DG and its associated DC subsystem cannot be declaredOPERABLE until it is connected electrically in place of another DG, and it hassatisfied applicable Surveillance Requirements.
(continued)
Watts Bar-Unit 1B 3.8-57Revision 113 DC Sources-Operating B 3.8.4BASESAPPLICABILITY The four vital DC electrical power sources and four DG DC electrical powersources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safeplant operation and to ensure that:a. Acceptable fuel design limits and reactor coolant pressure boundarylimits are not exceeded as a result of AOs or abnormal transients; andb. Adequate core cooling is provided, and containment integrity and othervital functions are maintained in the event of a postulated DBA.The DC electrical power requirements for MODES 5 and 6 are addressed in theBases for LCO 3.8.5, "DC Sources -Shutdown."
ACTIONSA.1. A.2. A.3. E.. E.2. and E.3Condition A. represents oe vital chrespond to an event, and a poteRti*a4nnol with a loss of ability to omepletely loss of ability to emi en .ergzd duringnormai operation.
it Is, tleretoe, imperative tnat peraltorsI1 at ostabilizing the plant, minimizing the potential for complete loss of .DC power to theaffecoted-trainR. The 2 hulismit is consistent With the alloweAAd_
timoP for aninoperable 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; chargorand associated ioRporablo bailer,'),
the remaining vital DG electrical poeresubsystem has the capacity to suppedt a. cafe s11-hutdown and to m~itigate anaccident conddition.
SinoR~ a subsequent worst case single failue of theOPE=RABLEm subsystem would, however, result in a sitution wfheerethe ability ofthe 125V DG electrical power subsystem to suppedt its required ESF function isnot assurFed, continRued power operation should not excoe d -2 hourws. T-he 2hourCompletion Time is based on Regulator,'
Guide 1 .93 (Ref. 8) and reflects
_areasonable time to assess plant status as a; func-tion of the inoperable vital PCelectirical power subsystem and, if the vital DC electrical power subsystemA is notrestore9d to- OPERABLE.
status, to prepare to effect an orderly and safe plantsh, 4tawn~(continued)
Watts Bar-Unit IB 3.8-58 DC Sources-Operating B 3.8.4BASESA B.!-and-
.2if the inoperablo8 Vital DC oloctrical power 6ubeystom cannoRQt be rosto4hroRd_
to-OPERABLE status within the required Complotion Time, the plant Must hebFrught to a MODE, iR Which the LCO not apply. To achieve this status, the-plant mAust be brog~lht to at least MODE 2 withnA 6 hourFS and to MODE 5 within368 hours. TPhe allowMAed Completion Times are reasonable, based an operatingf experience, to reach the required plant conditions frmF full power conditions ina4r lorderly mnanner and without challenging plant systems.
The Completion Timne tobring the plant to MODE 5 is6 Gconstent with the tiMe Feqw&#xf7;,ed in Regulator; Guide (Ref. 8).G_4Condition G represents one DG with a lss oef ability to chmpletely rosperad to aeveNt. Srinde a subrequet rsingle failue On the o ppoesite train coetd result in aatationa where the requ ired E cS function is not assured, eontirued poweropefation should wi t eXieed 2 hours .The 2 hous t ime WAelim f rinthe isnsenwith the allowed time foPR an inoperable vital DG electrical power subsystemr.
94If the DG Dr electrical power subsystem cannot be restored to OPERAbBLE sotatus in the associated Completier Time, the atssoeated Dh may beinapable of pemin mim g its intended functivo and muvistd be iAmeduately declared inorlThis declaratiero awls requires entry inte applicable conditions and RequiredActions 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).
TheACTIONS provide a tiered response that focuses on returning the battery to thefully charged state and restoring a fully qualified charger to OPERABLE status ina reasonable time period. Required Actions A.1 and E.1 require that the batteryterminal voltage be restored to greater than or egual to the minimum established float voltagqe within 2 hours. 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 theminimum established float voltage provides good assurance that, within 12hours, 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 currentportion (the second part) of its recharge cycle. The time to return a battery to itsfully charged state under this condition is simply a function of the amount of theprevious discharge and the recharge characteristic of the battery.
Thus there isgood assurance of fully recharging the battery within 12 hours, avoiding apremature 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 1B 3.8-59 DC Sources-Operating B 3.8.4BASESminimum established float voltage within 2 hours, and the charger is notoperating in the current-limiting mode, a faulty charger is indicated.
A faultycharger that is incapable of maintaining established battery terminal float voltaaqedoes not provide assurance that it can revert to and operate properly in thecurrent limit mode that is necessary during the recovery period following a batterydischarge event that the DC system is designed for.If the charger is operating in the current limit mode after 2 hours that is anindication that the battery is partially discharged and its capacity margins will bereduced.
The time to return the battery to its fully charged condition in this case isa function of the battery charger capacity, the amount of loads on the associated DC system, the amount of the previous discharge, and the rechargecharacteristic of the battery.
The charne time can be extensive, and there is notadequate assurance that it can be recharged within 12 hours.Required Actions A.2 and E.2 require that the battery float current be verified lessthan or equal to 2 amps for the vital battery and less than or equal to 1 amp forthe DG battery.
This indicates that, if the battery had been discharged as theresult of the inoperable battery charger, it is now fully capable of supplying themaximum expected load reduirement.
The 2 amp value for the vital battery andthe 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 theinitial 12 hour period the battery float current is not less than or equal to 2 ampsfor the vital battery or 1 amp for the DG battery, then this indicates there may beadditional battery problems and the battery must be declared inoperable.
Required Actions A.3 and E.3 limit the restoration time for the inoperable batterycharger to 72 hours. This action is applicable if an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established floatvoltage has been used (e.g., balance of plant non-Class 1 E battery charger).
The72 hour Completion Time reflects a reasonable time to effect restoration of thequalified battery charger to OPERABLE status.B.1 and F.1Conditions B and F represent one channel (subsystem) with one batteryinoperable.
With one battery inoperable, the DC bus is being supplied by theOPERABLE battery charger.
Any event that results in a loss of the AC bussupporting 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 behampered 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 dieselgenerator output circuit breakers, etc.) will likely rely upon the battery.
In additionany DC load transients that are beyond the capability of the battery charger andnormally require the assistance of the battery will not be able to be broughtonline. The 2 hour 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.) areidentified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specificCompletion Times.Watts Bar-Unit 1B 3.8-59a DC Sources-Operating B 3.8.4BASESC.1 and G.1Conditions C and G represent a loss of one DC electrical power subsystem tocompletely respond to an event, and a potential loss of ability to remainenergized during normal operation.
It is therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete lossof DC power to the affected subsystem.
The 2 hour limit is consistent with theallowed time for an inoperable DC distribution subsystem.
If one of the required DC electrical power subsystems is inoperable for reasonsother than Conditions A or B for the vital batteries or Conditions E or F for the DGDC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accidentcondition.
Since a subsequent worst case single failure could, however, result inthe loss of the minimum necessary DC electrical subsystems to mitigate a worstcase accident, continued power operation should not exceed 2 hours. The 2 hourCompletion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects areasonable time to assess unit status as a function of the inoperable DCelectrical power subsystem and, if the DC electrical power subsystem is notrestored to OPERABLE status, to prepare to effect an orderly and safe unitshutdown.
D.1 and D.2If the inoperable Vital DC electrical power subsystem cannot be restored toOPERABLE status within the required Completion Time, the plant must bebrought to a MODE in which the LCO does not apply. To achieve this status, theplant must be brought to at least MODE 3 within 6 hours and to MODE 5 within36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in anorderly manner and without challenging plant systems.
The Completion Time tobring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).9H.1If the DG DC electrical power subsystem cannot be restored to OPERABLEstatus 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 RequiredActions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."
Watts Bar-Unit 1B 3.8-59b DC Sources-Operating B 3.8.4BASESSURVEILLANCE REQUIREMENTS SR 3.8.4.1 and SR 3.8.4.2Verifying battery terminal voltage while on float charge for the batteries helps toensure 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 isthe condition in which the charger is supplying the continuous charge required toovercome 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 steadystate loads of the associated DC subsystem.
On float charge, battery cells willreceive adequate current to optimally charge the battery.
The voltagerequirements are based on the nominal design voltage of the battery and areconsistent with the minimum float voltage established by the batterymanufacturer.
For example the minimum nominal terminal voltage for the 5thVital Battery is 136V (62 cells times 2.20 Vpc), the minimum nominal terminalvoltage for the vital batteries is 132V (60 cells times 2.20 Vpc) and the minimumnominal 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 supportsmaintaining the grid life.The voltage requirements listed above are based on the critical design voltage ofthe battery and are consistent with the initial voltages assumed in the batterysizing calculations.
The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).SR 3.8.4.3Verifying that for the vital batteries that the alternate feeder breakers to eachrequired battery charger is open ensures that independence between the powertrains is maintained.
The 7-day Frequency is based on engineering
: judgment, is consistent with procedural controls governing breaker operation, and ensurescorrect breaker position.
SR 3.8.4.4This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning
: properly, with all required circuit breakers closed andbuses energized from normal power. The 7 day Frequency takes into accountthe redundant DG capability and other indications available in the control roomthat will alert the operator to system malfunctions.
SR 3.8.4.5 and SR 3.8.4.6Visual inspoc.tio.
U9 toe dotct corro.ion of the battey coIs and connections, ormoeasUr8Fem t of the rosistance of oach ineclitrak nooanda tor-minal connucu:n, pr1y.laec aRn indcic=tn Of pnyscI= damage OFr aonormna Eoe!rioraiu-on that could potentially dograd, battery pe.foermance.
These SRs verify the designcapacity of the vital and DG battery chargers.
According to Regulatory Guide1.32 (Ref. 6). the battery charger supply is recommended to be based on thelargest combined demands of the various steady state loads and the chargingcapacity to restore the battery from the design minimum charge state to therecharged state, irrespective of the status of the unit during these demandoccurrences.
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 1B 3.8-60 DC Sources-Operating B 3.8.4BASESSURVEILLANCE REQUIREMENTS SR 3.8.4.5 and SR 3.8.4.6 (continued)
The limits, established for thiS SR must be no more8 than 20% abovo theresistanco as mneasured during installation, or not above the cefiling valueestablished by the manufacturer.
The SRs provide two options.
One optionrequires that each vital battery charger be capable of supplying 200 amps (20amps for the DG battery charger) at the minimum established float voltage for 4hours. Recharging the battery or testing for a minimum of 4 hours is sufficient toverify the output capability of the charger can be sustained, that current limitadjustments are Properly set and that protective devices will not inhibitperformance 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. ThisFrequency is conrsidred acceptable based n opaerating expefienre related todetecting corrosion trends.rhe other option requires that each battery changer be caroable of recharging thebattery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the statusof the plant during which these demands occur). This level of loading may notnormally be available following the battery service test and will need to besupplemented with additional loads. The duration for this test may be longer thanthe charger sizing criteria since the battery recharge is affected by float voltage,temperature, and the exponential decay in charging current.
The battery isrecharged 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 toperform the test and the other administrative controls existing to ensure adequatecharger performance during these 18 month intervals.
In addition, thisFrequency is intended to be consistent with expected fuel cycle lengths.(continued)
Watts Bar-Unit 1B 3.8-61Revision 56, 69Amendment 54 DC Sources-Operating B 3.8.4BASESSR 3.8.4.7Visual inspec~tionA of the- batter,'
cells, cel! plates, and batter' rackrs provides, anin;dication of damage or abnormal deterioration that could potentially degrade batter.
The 12 mRonth Frequency for this SR is consistent With IEE 1~=450 (Ref. 9), Whichrecommendr, detailed visual insiqecti9n of coi cnd-ition and racRk intearity on ayea.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 powersystem. The discharge rate and test length should correspond to worst casedesign 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), whichstate 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 modifiedperformance discharge test in lieu of a service test. The modified performance discharge test is a simulated duty cycle consisting of must two rates; the oneminute 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 whichenvelope the duty cycle of the service test. Since the ampere-hours removed bya rated one minute dischar-ge represents a very small portion of the batterycapacity, the test rate can be changed to that for the performance test withoutcompromising the results of the performance discharge test. The batteryterminal voltage for the modified performance dischar-ge test should remainabove the minimum battery terminal voltage specified in the battery service testforthe 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 performthe function specified by this Surveillance, for which adequatedocumentation of the required performance is available; and2.) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in coniunction withmaintenance required to maintain OPERABILITY or reliability.
Watts Bar-Unit 1B 3.8-61 a DC Sources-Operating B 3.8.4BASESSR 3.8.4.8.
SIR. 3.8.41.9-aind SR 3.8.1.10Visual inspection and resistance measuremonts of intrcl, ntrac 8 nede,and- terminall connectfions provide an indication Of physical damage or abnormaldeterioration that could indicate degraded batter; condition.
The anticorrosion mnaterial is used to help ensure good 8eletricial connections and to reducetermin-al deterioration.
The visual inspection for corrosionA is not inended toreqireremval of an~d inspection under eac-i-h termin-al cneto.The remoevalof voisibhle corrosio isa rentive mnaintenance SR. The presence of visiblecorrosion does not necessarily r-epresent a; failure of thisSRpoievsbl coroson s emoved duFrin pedoF~armanc of SR 3.8.1.8.
For the purposes oftrending, inter cell (vital and DG batteries) and inter tier (vital and DG baftteies) connecR6tionsG are measured from batter' post to batter; post. Inter rack (vitalbatteries),
inter tier (DG Batteries),
and terminal connec8tions (vital And DGbatteries) are measure-d
*fro terminal lug to battery post-.Watts Bar-Unit 1B 3.8-61 b DC Sources-Operating B 3.8.4BASESSURVEILLANCEIISEMENTS SR 3.8.4.8.
SR 3.8.4.9 and SR 3.8.1.10 (continued)
The cnneRctin res;hL 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 Mnccoiling 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 eThis SR requires that each vital battery charger be capable of itsa ssoci ated batter; from a capacity or sor~ice discharge test while supplying normal loads, Or alternatively, operating at Iimit for a minimumA of 1 houlrsat a nominal 1215 VDCG. These .rq irmnts are based en the design capacity ofthe chargrs (Ref. 4) and theiF r performanc charaGteristic of curre9nt Imfitoperation for a substantial portion of the recharge period. Batter; charger outputcurrent oi, limited to 110% 125% of the 200 amp rated output. Reharfgirg thebailer' or testing for a minimum of 14or ssfiin to verify the outputcapability Of th chaFrger cncy be susained, that g-cuent limit adjustments areproperly set and that protective Will not pefor.ance at currentlimit settngs.
According to Regulator,'
Guide 1.32 (Ref. 6), the batter,'
charg@ersupply is requir~ed to be based en the largest combined demands of the varioussteady state leads and the charging capacity to restore the batter; from thedesign mcharge state to the fully charged state, irrespective of the statusof the plant during these dem,,and, occu..
Verifying th8 capability of thecharger to operate in a sustained courrent limit condition ensures that theserequirements 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 adequatcharger performnance durinig these 189 month finter~vals.
in addition, thisFrFequency is inten-ded_
to bhe consistent With expected fuel cycle lengths.(continued)
Watts Bar-Unit 1B 3.8-62 DC Sources-Operating B 3.8.4BASES 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 MOIDES 5ad 6 SO.nc it would ro.uiro the G subsystom to b ,Rnoperablo during po.formanc
.of the test. HoweV.. , thi. Sur.eillan.
e Maybe on MODES 1, 2, 3, Or 4 proIided the Vital B&#xf7;atte V , risubstituted in accordance With LCO Note 1. Credit mnay be takenfounplanned events that Gatwsf' this SR. Examples of unplanned events may1) Unexpected operational events which cGause the equipment toperformn the function specified by this SUrVeillaAce,
'For WhIchadequate Of equired e is available; a~d2) Post ..rrective maintenance te.sting that requires performance of.... ... .... ..~ ... .. 4.. ., ......" ...''H.; u;. emn.;; ; e.,r w;;";".:
;;'.p'evi-et mte manternare Wtwith mRaintenaneruid t(as required, or pefoFrmed in conjunction maintain OPERBILI TY Or reliability.
-SR3.84.!2 T-his SR requires that each diesel generator battery charger be capable ofrech~arging itro associated battery from a capacity Or GerV9Ge diScharge test whilesupplying normnal loads, Or altebatively, operating at current limit for a of 41 1"2 hos at a nominal 125 This requirement irs based On the designcapacity Of the chargers (Ref. 13) and their perfoFrmance character istic. Of currentlimnit for a substantial 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 toRegulator,'
Guide 1.32 (Ref. 65), the battery .charger supply is, required to bebased on the largest combined demands of the various steady state loads andthe charging capacity to restoeM the battery from the desg minmu c :hargestate to the fully charged state, irrFespective of the status, of the plant during thesedemand occurrences.
Verifying the capability of the charger to operate in asuIstained current limfit GGondition; ensures that these requirements can be6atmfiefld.
(continued)
Watts Bar-Unit 1B 3.8-63Revision 112 DC Sources-Operating B 3.8.4BASESSU IDRVEI IL LA.NCEIGi=
REQlIREENlTS; SR 3.8.4412(ctnud The Sur.'eillance FrFequency is acceptable, given the plant conditions required toperformA the test and thes other administrative controls existing to ensure adequate peFr4frmanle during these 18 month interals.
In addition, thisFrFequency is intended to be consistent With expected fuel cycle lengths..Fo the DG DG electrical subsystem, this Su.ei 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 andwould net otheWrxs challenge safety systems supplied from vital electrical distr&ibution systems.
if available, tfhe G , UG and its assoc.iated PC eir" power subsystem
.may be substituted in .ac .rdan.e.
.ith LO Note 2.Additionally, credit may be taken for unplanned events that satisfy+
this, SRExamp!es of unplanned events may inc'lude:
: 1) Unexpected operational events which cause the equipment to performRthe function specified by this Surveillance, for which adequate-documnentation of the required performnance is available; and2) Pest cor-rec~tive maintenance testing that requires perfoFrmance of this,Survillnce n oder to restore the component to OPERA.BLE, providedthe 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 thdeswRg (battery' duty cycl,) Of the DG power system,.
The,discharge rate and test length should correspond to wonrst case design dluty cyclrequirements based On Reference.0 and 12.The Surveillance rFrequency of 18 mo~nths is consistent with therecommendations 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 1B 3.8-64Revision 19, 66Amendment 12 DC Sources-Operating B 3.8.4BASESSURVEILLA.hCE REQUIREMENTS SR3..11 (continued)
T-his SR is moedified by two Notes. Noto I allows tho performFance of a modifiedperformnance discharge test in lieu of a servic~e test once per 60 mon~ths.
Themoedified performance discharge test is a simulatod duty cycle consisting of justtwo rates; the one minute rate published for the batter,'
Or the largest current loadof the duty cycle, followed by the test rate employed for the perforancwe test,bonth of %whic-h envelope the duty cycle of the ser~ice testf. SiOnce the am~perehours6 removed by a rated one minute discharge represents a vory' small portionof the battory capacity, tho test rate can be changed to th-at for the performFance tes without 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.rA moedified discharge test is a test of the bailer,'
capacity and its ability to providea 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 dutycycle, in addition to deteMrminin its percentage Of rated capacity.
Initial:conditions for the moedified performance discharge test should be identicall tothose specified for a ser:ice test.Theuron ,,+for Note 2 is that the Sur ..illance may prturb the Vitale~lecrtric~al dis-tribution systemn and- challenge safety systemsR.
: How8eve, thisSuryeillance may be performed inMODES I, 2, 3, Or 4 provided that Vital Bailer;LVsusten accordance wiNot e 2. dtC0nIA-,
: 1. Foyr the OG QC elnctrical ubs.ystems, this sur-i..ancmay be performed in MODES , 2, 3, or 4 incejntinwt LCO 3.8.l.B since the supplied loads are only for the inoealdislgeeao and would not othorwffise challenge safety system leas; wAhic-hare supplied fromR vital electrical distribution systemsr.
if available, the C S DGand its associated DG electrical power subsystemA may be substituted inaccordance With LCO Note 2. Additionally, credit mnay be taken for unplanned events that satisb' this SR. Examples of unplanned events mnay icue1) Unexpected operation-al e-venIts which cause the equipment to performAhe8 umntiAon specified docum~entation of thei dl IIll F I i ibv thi6 Surveiiiance ror Wnic aaeouate.--j .-- --* i..........
7 ... ........* ui Iroqui're penr,,anco s available;
-and(continued)
Wafts Bar-Unit 1B 3.8-65Revision 12Amendment 12 DC Sources-Operating B 3.8.4BASESSUVI\rll ANCE'r SR 3.8.1.13 (contnuod),,rl REQUIREMENTS
: 2) Poet corecF8tivo maintonance totting that roquires perform~anco Of thisSur.'eilance in orFder to restore the component to OPERABLE, providedthe mnaintenance Was, required, Or perfoFrmed in conjunction withmnaintenance required to mnaintain OPERABILITY or reliability.
SR-3.9.4.44 A bailer,'
performance discharge test is, a test of. cnwstant current capacity of abailer,',
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 for32.8.1.123.
Eithe the batter,'
perforaEn;e diechargo test Or the modifiedperfoqrmance discharge testis6 acceptable foFrsatisfYing SR 3.8.4f1.;
however,only the modified rancs e discharge test May be used to satisfy SR 3.5.1.11while satisfying the requiremfents of SR 3.8.1.13 at the same time.The crteria; for this Su, ,feillane are cRonsistent with IErEE= 450(Ref. 9) and IEEE 15 (Ref. 5). Thhese references d rco.meAd that the balefr, bereplaced if its capacity is, belo)w 80% of the- manuf.act'urer rating. A capacity of80% chews that the bailer,'
rate of deterioratio i ncesRg even if there isample 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 andcapacity is 100% o~f the m~anufacturer's rating, the Suryeillance Freuec ' Isreu edt 1_2 months. H'A; A"owever, if the baile~yrshows no degradation but hamsreachedd 8-5%. of its expected life, the Suw.eillance FrFequency is only reduced to21. 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 bailercapacity drops by mor9e than 1 0% relative to its capacity on the preiuperformnance test or wMhen it is > 10%5 belowA the MAnu facturer rating. TheseFFreuencies are c~~wonitent with the recommFn~endations fin IEEE 150 (Ref.91t(continued)
Waits Bar-Unit 1B 3.8-66Revision 19Amendment 12 DC Sources-Operating B 3.8.4BASESSURVEILLANCE REM EN5AI: SR 3.8.4.14 (continued),
This SR is modified by a Note. The reason for the Note is that pefeorming theSurveillance 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 inMODES I, 2, 3, Or 4 in conjuncfion With LCO 3.8.l.B since the supplied leads areonly fr the inoperable diesel generator
,and would net etherise challenge safetysystem leads which are supplied frem vital electri;cia systems.
ifavalable, the C S DG and isassociated DG electrial power subsystem may besubstituted in accor~dance With LCO Note 2. Additionally, credit may be takenfrunplanned events, that satisfy this SR. Examples of unplanned events mnay1 ) Unexpected operational events which cause the equipment to performn the-tunction.
specitied by tiof the required perforn2) Post corrective mainteSurvillncein order tihiG SeFVe aAGe,tor W..c.h adequate ej an4nance testing that requires performnance oftD restore the component to OPERABLE, prorequired, Or performed in conjunction with-to maintain OPERAB-ILITY or reliability.
hiev'-dtcdtne m~aintenance wasm~aintenance required(continued)
Wafts Bar-Unit 1B 3.8-67 Revision 19Amendment 12 DC Sources-Operating B 3.8.4BASESREFERENCES
: 1. Title 10, Code of Federal Regulations, Part 50, Appendix A, GeneralDesign 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 forNuclear 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 LeadStorage Batteries for Generating Stations and Substations,"
Institute ofElectrical and Electronic Engineers.
: 6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric PowerSystems for Nuclear Power Plants,"
February 1977, U.S. NuclearRegulatory 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 1974.910.IEEE 150) 1980!11995, "IEFEE Rocommended Practice for Main teAnceGToSting and Replacemnent of Largo Load Storage Battoriesfo Generating Stations and Subsystems,"
Institute of Elec8trical andElec"Rnic Engineers..
IEEE-450-2002, "IEEE Recommended Practice forMaintenance, Testing and Replacement of Vented Lead -Acid Batteries for Stationary Applications,"
Institute of Electrical and Electronics Engineers, Inc.TV4A CGaIulation WBN EEB MS TIl-l 1-0003, "125 VDC Vital Batter' y anCharger Evalation.:"
TVA Calculation EDQ00023620070003, "1 25V DCVital Battern System Analysis."
: 11. Regulatory Guide 1.129, "Maintenance Testing and Replacement ofLarge Lead Storage Batteries for Generating Stations and Subsystems,"
U.S. Nuclear Regulatory Commission, February 1978.(continued)
Watts Bar-Unit 1B 3.8-68 DC Sources-Operating B 3.8.4BASESREFERENCES
: 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 1B 3.8-69 DC Sources -ShutdownB 3.8.5B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.5 DC Sources -ShutdownBASESBACKGROUND A description of the DC sources is provided in the Bases for LCO 3.8.4, "DCSources -Operating."
APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume that Engineered Safety Feature systems are OPERABLE.
The vital DC electrical power systemprovides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation.
The DGbattery systems provide DC power for the DGs.The OPERABILITY of the DC sources is consistent with the initial assumptions ofthe accident analyses and the requirements for the supported systems'OPERABILITY.
The OPERABILITY of the minimum DC electrical power sources duringMODES 5 and 6, and during movement of irradiated fuel assemblies ensuresthat:a. The plant can be maintained in the shutdown or refueling condition for extended periods;b. Sufficient instrumentation and control capability is available formonitoring and maintaining the plant status; andc. Adequate DC electrical power is provided to mitigate eventspostulated during shutdown, such as a fuel handling accident.
The DC sources satisfy Criterion 3 of the NRC Policy Statement.
(continued)
Watts Bar-Unit 1B 3.8-70 DC Sources -ShutdownB 3.8.5BASES (continued)
LCO The 125V Vital DC electrical power subsystems, each vital subsystem channelconsisting of a battery bank, associated battery charger, and the corresponding control equipment and interconnecting cabling within the channel; and the DGDC electrical power subsystems, each consisting of a battery, a battery charger,and the corresponding
'control equipment and interconnecting
: cabling, arerequired to be OPERABLE to support required trains of the distribution systemsrequired OPERABLE by LCO 3.8.10, "Distribution Systems -Shutdown" and therequired DGs required OPERABLE by LCO 3.8.2, "AC Sources-Shutdown."
As aminimum, 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 and2B-B) shall be OPERABLE.
This ensures the availability of sufficient DCelectrical power sources to operate the plant in a safe manner and to mitigate theconsequences of postulated events during shutdown (e.g., fuel handlingaccidents).
The LCO is modified by twefour Notes. Note 1 indicates that Vital Battery V maybe substituted for any of the required vital batteries.
: However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.
Note 2indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted forrequired vital chargers.
Note 3 indicates that spare DG chargers 1A1, 181, 2A1,or 2B1 may be substituted for required DG chargers.
: However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.
Note 4 har beon added to indicates that the C-S DG and itsassociated DC subsystem may be substituted for any of the required DGs.However, the C-S DG and its associated DC subsystem cannot be declaredOPERABLE until it is connected electrically in place of another DG, and it hassatisfied 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 areavailable; (continued)
Watts Bar-Unit 1B 3.8-71 DC Sources -ShutdownB 3.8.5BASESAPPLICABILITY
: b. Required features necessary to mitigate the effects of events that can(continued) lead to core damage during shutdown are available; andc. Instrumentation and control capability is available for monitoring andmaintaining the plant in a cold shutdown condition or refueling condition.
The DC electrical power requirements for MODES 1, 2, 3, and 4 are covered inLCO 3.8.4.ACTIONSA.1, A.2.1, A.2.2, A.2.3, and A.2.4If two trains are required by LCO 3.8.10, the remaining train with DC poweravailable may be capable of supporting sufficient systems to allow continuation ofCORE ALTERATIONS and fuel movement.
By allowing the option to declarerequired features inoperable with the associated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with theaffected required features LCO ACTIONS.
In many instances, this option mayinvolve undesired administrative efforts.
Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movementof irradiated fuel assemblies, and operations involving positive reactivity additions).
The Required Action to suspend positive reactivity additions does notpreclude actions to maintain or increase reactor vessel inventory, provided therequired SDM is maintained.
Suspension of these activities shall not preclude completion of actions toestablish a safe conservative condition.
These actions minimize probability ofthe occurrence of postulated events. It is further required to immediately initiateaction to restore the required vital DC electrical power subsystems and tocontinue this action until restoration is accomplished in order to provide thenecessary DC electrical power to the plant safety systems.(continued)
Watts Bar-Unit 1B 3.8-72 DC Sources -ShutdownB 3.8.5BASESACTIONS 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 foractions requiring prompt attention.
The restoration of the required vital DCelectrical power subsystems should be completed as quickly as possible in orderto minimize the time during which the plant safety systems may be withoutsufficient power.B. 1If theone or more required DG DC electrical power subsystem cannot be restoredto OPERABLE status in the associated Completion Time, the associated DGmay 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 3.8.5.1REQUIREMENTS SR 3.8.5.1 requires performance of all Surveillances required by SR 3.8.4.1through SR 3.8.4.4-47.
Therefore, see the corresponding Bases for LCO 3.8.4 fora 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 toprovide the required power supply or otherwise rendered inoperable during theperformance of SRs. It is the intent that these SRs must still be capable of beingmet, 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 1B 3.8-73 Battery Geti-Parameters B 3.8.6B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.6 Battery Gell-Parameters IBASESBACKGROUND 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 vitalDC electrical power subsystem and the diesel generator (DG) batteries.
Adiscussion of these batteries and their OPERABILITY requirements is provided inthe Bases for LCO 3.8.4, "DC Sources -Operating,"
and LCO 3.8.5, "DCSources -Shutdown."
Additional controls for various battery parameters are alsoprovided in Specification 5.7.2.21, Battery Monitoring and Maintenance Program.The battery cells are of flooded lead acid construction with a nominal specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts Per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital batter) the total minimum outputvoltage is 124V and for a 62 cell battery (5th vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or dischar-ging.
Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further chargingper manufacturer's instructions.
Optimal long term performance
: however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfate and selfdischarge as discussed in FSAR, Chapter 8 (Ref. 4).APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident (DBA) and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume Engineered SafetyFeature systems are OPERABLE.
The vital DC electrical power system providesnormal and emergency DC electrical power for the emergency auxiliaries, andcontrol and switching during all MODES of operation.
The DG battery systemsprovide DC power for the DGs.The OPERABILITY of the DC subsystems is consistent with the initialassumptions of the accident analyses and is based upon meeting the designbasis of the plant. This includes maintaining at least one train of DC sourcesOPERABLE during accident conditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.Battery eelI-parameters satisfy the Criterion 3 of the NRC Policy Statement.
ILCO 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 safecondition after an anticipated operational occurrence or a postulated DBA.(continued)
Watts Bar-Unit 1B 3.8-74 Battery Ge#-Parameters B 3.8.6IBASESLCO(continued)
EGt Batter parameter limits are conservatively established, allowingcontinued DC electrical system function even with Catogo.y A and B limits notmet. 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 beOPERABLE.
Refer to the Applicability discussion in Bases for LCO 3.8.4 andLCO 3.8.5.ACTIONSA.1, A.2, an4-A.3, C.1, C.2, and C.3With 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 ry A and B li mit..nt Met) but-within the Categor; C limits specified in; Table 3.8.6 1 in the accomnpanyin
_LCO,Ithe eator-y is dograded but mor~e is Still 6uRncIent capacity to ponormF~
tne_ Wendedfunction9.
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 ispe~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 hour (Requirod Action Al). This* check willpoide a quick iniainof the status of the remainder of the batter; cells. Onhour 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) providesassurancGe that during the time needed to restore the parameters to theCategory A and B3 lfimits, the batter,'
is still capable of perfo9Frming its intendedfunction.
A period of 24 hours 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 requiredVerification and the assurance that the batter' coil! paramneters are not seVerelydeqraded, this ti~me is; con9sidered reasonable.
The veiiainis reeated at 7(continued)
Watts Bar-Unit 1B 3.8-75 Battery Cell-Parameters B 3.8.6BASESACTIONSA.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.
Th486poriodic verification ie consistent with the normal Frequency of pilot ceilContinued operation i6 erly permirted for 31 days before bastto, onel parameter muot boe rstored to Withir Categrr; A and B3 limits. With the cosidveratio that,while battery caapacity is degraded, sucot capacity misI to rio theinternded fuction and to allow. time to fully .8. tofe the batte ry cell parameters toarmeal limoit, this time is acceptable pcrqi to declarnRg the batery inoperSable.
If one required vital battery or one required DG battery has one or more cellvoltage <2.07 V. the battery is considered degraded.
Within 2 hours verification of the required battery charger OPERABILITY is made by monitoring the batteryterminal voltage (SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state ofcharge by monitorinq the 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 intendedfunction.
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 andcontinued operation is permitted for a limited period up to 24 hours.Since the Required Actions only specify "Perform,"
a failure of SIR 3.8.4.1.
SIR3.8.6.1, SIR 3.8.4.2.
or SR 3.8.6.2 acceptance criteria does not result in thisRequired 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 battervcapacity to perform the intended function and the battery must be declaredinoperable immediately.
B., B.2. D.1. and D.2With oequ Or moa batteries with ona Or More battemp' cl parameters ouir tside theCategory C limits for any coennected coil, sufficient capacity to supply themaximu.ml eAxpcted load requirement is not asrF;; ed and the corresponding VitalDG or DG DG electrical power subsystem must be declaredinprbe Additionally, other potentially extroeFA conditions, such as not completing theRequired Ac-tions of Condition A within the required Completion Timeo vrgelectrel4e temperature Of representatiVe cells falling below 60OF for the vitalbatteries Or 600F for DG_ batteries, are also cause forF immediately declamrig theassciaedVital DG Or _DG DG electrical power subsysteminpeabe One required vital battery with float current > 2 amps or one required DG batterywith float current > 1 amp indicates that a partial discharge of the battery capacityhas occurred.
This may be due to a temporary loss of a battery charger orpossibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity.
Within 2 hours verification of the required battery chargerOPERABILITY is made by monitoring the battery terminal voltage.(continued)
Watts Bar-Unit 1B 3.8-76 Battery -eII-Parameters B 3.8.6BASESIf the terminal voltage is found to be less than the minimum established floatvolta-ge there are two possibilities, the battery charqer is inoperable or isoperating in the current limit mode. Condition A and C address chargerinoperability.
If the charger is operating in the current limit mode after 2 hoursthat is an indication that the battery has been substantially discharged and likelycannot perform its required design functions.
The time to return the battery to itsfully 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 previousdischarge, and the recharge characteristic of the battery.
The charge time canbe extensive, and there is not adequate assurance that it can be recharged within 12 hours (Required Actions B.2 and C.2). The battery must therefore bedeclared inoperable.
If the float voltage is found to be satisfactory but there are one or more batterycells with float voltage less than 2.07 V. the associated "OR" statement inCondition H is applicable and the battery must be declared inoperable immediately.
If float voltage is satisfactory and there are no cells less than 2.07V there is good assurance that, within 12 hours, the battery will be restored to itsrecharged condition (Required Actions B.2 and C.2) from any discharge thatmight 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 (thesecond 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 previousdischarge and the recharge characteristic of the battery.
Thus there is goodassurance of fully rechar-ging the battery within 12 hours, 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 stillgreater than 2.07 V and float voltage is found to be satisfactory, this is notindication of a substantially discharged battery and 12 hours is a reasonable timeprior to declaring the battery inoperable.
Since Required Actions B.1 and C.1 only specify "perform,"
a failure of SR3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in the Required Actionnot 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.3With one required vital or DG battery with one or more cells electrolyte levelabove the top of the plates, but below the minimum established design limits, thebattery still retains sufficient capacity to perform the intended function.
Therefore, the affected battery is not required to be considered inoperable solely as a resultof electrolyte level not met. Within 31 days the minimum established designlimits for electrolyte level must be re-established.
(continued)
Watts Bar-Unit 1B 3.8-76a Battery Gell-Parameters B 3.8.6BASESWith electrolyte level below the top of the plates there is a potential for dryoutand plate degradation.
Required Actions E.1 and E.2 addressed this potential aswell as provisions in Specification 5.7.2.21
.b, Battery Monitoring andMaintenance Program.
They are modified by a Note that indicates they are onlyapplicable if electrolyte level is below the top of the plates. Within 8 hours level isrequired to be restored to above the top of the plates. The Required Action E.2requirement to verify that there is no leakage by visual inspection and theSpecification 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. Theyare performed following the restoration of the electrolyte level to above the top ofthe plates. Based on the results of the manufacturer's recommended testing thebattery may have to be declared inoperable and the affected cell(s) replaced.
F. 1With one required vital or DG battery with pilot cell temperature less than theminimum established design limits, 12 hours is allowed to restore thetemperature to within limits. A low electrolyte temperature limits the current andpower available.
Since the battery is sized with margin, while battery capacity isdegraded, sufficient capacity exists to perform the intended function and theaffected battery is not required to be considered inoperable solely as a result ofthe pilot cell temperature not met.G.1With more than one required vital or more than one DG batteries with batteryparameters not within limits as specified in Conditions A through F there is notsufficient assurance that battery capacity has not been affected to the degreethat the batteries can still perform their required
: function, given that redundant batteries are involved.
With redundant batteries involved this potential couldresult 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 mustbe restored to within limits on at least one subsystem within 2 hours.H.1With one or more batteries with any battery parameter outside the allowances ofthe Required Actions for Condition A. B. C, D. E, F or G sufficient capacity tosupply the maximum expected load requirement is not assured and thecorresponding battery must be declared inoperable.
Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 Vand float current greater than 2 amps for the vital batteries or 1 amp for the DGbatteries indicates that the battery capacity may not be sufficient to perform theintended functions.
Under these conditions, the battery must be declaredinoperable immediately.
(continued)
Watts Bar-Unit 1B 3.8-76b Battery Getl-Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.1 and SR 3.8.6.2REQUIREMENTS Thus SIR verifies; that Gategeoy A battory' oel! parame~toeF aro concictont withIEEE 450 (Ref. 2), Which rocomm~end6 regular battery' inspectionc (at least oeepor monith) including
: voltage, specific
: gravity, and oloctrOlyte tem~porature Of pilot-Verifying battery float current while on float charge is used to determine the stateof charge of the battery.
Float charge is the condition in which the charger issupplying the continuous charge required to overcome the internal losses of abattery and maintain the battery in a charged state. The equipment used tomonitor float current must have the necessary accuracy and resolution tomeasure electrical currents in the expected range. The float current requirements are based on the float current indicative of a charged battery.
The 7 dayFrequency is consistent with IEEE-450 (Ref. 2).This SR is modified by a Note that states the float current requirement is notrequired to be met when battery terminal voltage is less than the minimumestablished float voltage of SR 3.8.4.1 or SR 3.8.4.2.
When this float voltage isnot maintained the Required Actions of LCO 3.8.4 ACTION A or E are beingtaken, which provide the necessary and appropriate verifications of the batterycondition.
Furthermore, the float current limit of 2 amps for the vital battery and 1amp for the DG battery is established based on the nominal float voltage valueand is not directly applicable when this voltage is not maintained.
(continued)
Watts Bar-Unit 1B 3.8-76c Battery GeU-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)
The qlurterly inspectio 9f specific gravity and voltage is consistont tIEFEE 450 (Ref.2).
in additi*on, within 24 hours of a batter; discharge
-1 10V(11 3.5V forF Vital Batter,'
V or-F 106.5P forF PG batterie6) or a batter; ovorchargo
>1 50V (15P -V for Vitalol Bailer; V Or 145VI for -DG- battor9ies),
the batter; mnust be4D -A U +"kI...... Ipn ~ o ".k;.I, rat a,. vnn~ptfrll rMn 0. raofa ~ +s ~ 4 4f'~ ~I(I ! 3.5V for Vital Batter; V or 106.5V for DG batteris),
doa not constitute a battorpdi'charge pro"ided the battery terminal voltage and float current return to protra-nsiet values. This ;nspe-ti-n is a6o9 consistent With !EEE 1-r-50 (Rf.2), whicrecommeInds special inspections following a sovero d icharge or tooRo that no significant degradatiOn of the bailer- occurS as a .. .cnquence Ofsuch discharge Or oVer-harge.
SR-3.3aThis Su'eillancq verific ation that the averago tempratue Of represenn toativ cellstis f 600F for the vital batteries, and 501F for the vit G batteriesI, is oansistnt 1wtha recommtendation of IheE 450 (Ref. 2), that states that the temperature Ofpotenales in representative clatils should be determned se a quadterly basis.';Lower than no~rmal temperatures act to inhibit or reduce batter; capacity.
T-hisSR eRnsure rS that the operating temiperatues Fremain within an aceptable operating range. This limipt ibarsed n manu fac recommendations5.7.2.21.
SA sSR 3.8.6.3 and SR 3.8.6.6Optimal long term battery performance is obtained by maintaining float voltagegreater than or equal to the minimum established design limits Provided by thebattery manufacturer which is 2.20 Vpc. This corresponds to a terminal voltageof 128V for the IDG batteries.
132V for the vital batteries I through IV and 136Vfor the vital battery V. The specified float voltage provides adequate over-potential, which limits the formation of lead sulfate and self discharge.
whichcould eventually render the battery inoperable.
Float voltages in this range orless, but greater than 2.07 Vpc. are addressed in Specification 5.7.2.21.
SRs3.8.6.3 and 3.8.6.6 require verification that the cell float voltages are equal to orgreater than the short term absolute minimum voltage of 2.07V.The Frequency for cell voltagqe verification every 31 days for pilot cell and 92days for each connected cell is consistent with IEEE-450 (Ref. 2).SR 3.8.6.4The limit specified for electrolyte level ensures that the plates suffer no physicaldamage and maintains adequate electron transfer capability.
The minimumdesign electrolyte level is the minimum level indication mark on the battery cellDar. The Frequency is consistent with IEEE-450 (Ref. 2).(continued)
Watts Bar-Unit 1B 3.8-77 Battery Gel4-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)
SR 3.8.6.5This Surveillance verifies that the pilot cell temperature is greater than or equal tothe minimum established design limit (i.e., 60 &deg;F for vital batteries and 50 OF forDG batteries).
Pilot cell electrolyte temperature is maintained above thistemperature to assure the battery can provide the required current and voltage tomeet the design requirements.
Temperature lower than assumed in batterysizinq calculations will not ensure battery capacity is sufficient to perform itsdesign function.
The Frequency is consistent with IEEE-450 (Ref. 2).SR 3.8.6.7A battery performance discharge test is a test of battery capacity using constantcurrent.
The test is intended to determine overall battery degradation due to ageand 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 modifiedperformance discharge test may be used to satisfy the battery service testrequirements of SR 3.8.4.7.A modified performance test is a test of the battery capacity and its ability toprovide a high rate, short duration load (usually the highest rate of the dutycycle). This will often confirm the battery's ability to meet the load duty cycle, inaddition to determining its percentage of rated capacity.
Initial conditions for themodified performance discharge test should be identical to those specified for aservice test.It may consist of must two rates; for instance the one minute rate for the battery orthe largest current load of the duty cycle, followed by the test rate employed forthe 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 verysmall portion of the battery capacity, the test rate can be changed to that for theperformance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge testmust remain above the minimum battery terminal voltage specified in the batteryservice 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 bereplaced if its capacity is below 80% of the manufacturer's rating. A capacity of80% shows that the battery rate of deterioration is increasing, even if there isample capacity to meet the load requirements.
Furthermore, the battery is sizedto meet the assumed duty cycle loads when the battery design capacity reachesthis 80% limit.(continued)
Watts Bar-Unit 1B 3.8-77a Battery Cl-U-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)
SR 3.8.6.7The Surveillance Frequency for this test is normally 60 months. If the batteryshows degradation, or if the battery has reached 85% of its expected life andcapacity is < 100% of the manufacturer's ratinq, the Surveillance Frequency isreduced to 12 months. However, if the battery shows no degradation but hasreached 85% of its expected life, the Surveillance Frequency is only reduced to24 months for batteries that retain capacity
> 100% of the manufacturer's ratingqs.
Degradation is indicated, according to IEEE-450 (Ref. 2), when the batterycapacity drops by more than 10% relative to its capacity on the previousperformance test or when it is > 10% below the manufacturer's rating. TheseFrequencies 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 totake credit for unplanned events that satisfy this SR. Examples of unolanned events may include:1) Unexpected operational events which cause the equipment to performthe function specified by this Surveillance for which adequatedocumentation of the required performance is available:
and2) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in coniunction withmaintenance required to maintain OPERABILITY or reliability.
Tab R .. II flic table doinoAwtoc, tIo liMite On oioctroi&#xfd;'
level, Peoat veltagoe, and 6pocitictor tFro Elioron"t I Th meaning ot eac-ih catog-rly
: i. iicGusedbelow.(continued)
Watts Bar-Unit 1B 3.8-77b Battery GeHl-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS T-lable 3.81 (cnrtinRLud)
Category A defines the normnal paramneterF limit forF each designated pilot coil'ieach bailer;.
The cells selected as pilot cells are those whose temperature,
: voltage, and electrolyte specific gravity approximFate the s~tate of charge of theentm~e bate.9eThe Category A limits specified for electrolyte level are based OR nmanufacturer 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 beabove the spec-ifie-d mfaximumA level during equalfizing charge, provided it is; notoverflowing.
These limffits ensure that the plates suffer no physical damage, andthat adequate electFro transfer capability is m~aintafined in the event of transient condtios.
EEE 150 (Ref. 2) recommenAds6 that electrolyt4e level readings shouldbe made only after the battery has been at float charge for at least 7:2 hou rs.The Category A limit specified forfloat voltage i2.13 V per cell. This value ibased On the recommendations of IFEEE 150 (Ref. 2), which states thatprolonged operation of cells -2. 13 ZcanR 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 abatterycharging 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 (25PC+.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 tothe reading; 1 point is subtracof the electrolyte in a cell'nrevape~aeen.
eafor each 3 OF below 77 OF. The specfic gravitys with a loss of water dlue to electrolysis Or(continued)
Watts Bar-Unit 1B 3.8-78 Battery IB 3.8.6BASESSURVEILLANCE REQUIREMENTS Table 3.8.6 1 (continued)
Category B defines the normal paFrameter limits for each connoct1ed ell. ThotermF "connecGted-cell" excludes any batter; coil! that ma" be jumnpered out.The Category B limits specified for electrolyte level and float voltage are thesame as those specified for Category A and have been discussed above. TheCategery B limit specified for specific gravity for each GRnlneted cell is, 1.195(0.020 below the mnanufacturer fully charged, nomninal specific gravity) with theaverage of all connected cells> 1.205 (0.010 below the m~anufacturer fullycharged, nominal specific gravity).
These values, are ba-sed on manufacturer's recommFendations.
The miiumseific gravity value required for each cellensueres that the effects of a hihl chredo newly installed coil! Will net m~askoverall degrad-ation of the battery.Category C defines, the limnits for each coennecrte-d c~ell. These values, althoughreduced, provide assrUanco that sufficient capacity exists to pe~form.
the intenRd-e function and maintain a mnargin Of Safety. When any battery parameter is; eotsid'the Category C limits, the assurance Of sufficient capacity described_
-above nolonger exists, and the battery must be declared inoperable.
The Category C limnits specified for electrel'e level (above the top of the plates48-m.mait-ain ad-equate electron transfer capability.
The&Gatgory C limits for floatvoltage is, based en IEEE 450 (Ref. 2), which states that a coil' voltage of 2.07-VOr below, und~er float conditions, and not caused by elevated temperaturwe of thecell, iniatsinenl!
coiprblems and may reur cl eplacem~ent.
The Category C limi~ts Of avrg speific gravit" 1.195 is basedomnanufacturer recommendations (0.020 below the(continued)
Watts Bar-Unit 1B 3.8-79 Battery Gell-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS Tablo 3.9.6 1 (continued) manufactuwrernrcmmended fully charged, F)nominal specific gravity).
in additionto that 10Alimt, itiFequired that the specific graVity forF each connecte coil mus't beno le-ss than 0-0 below-4 the average of all connecated coils. This limit ensueresthat the effect of a highly charged Or new. c&#xfd;ell doAesF Mat m.a-ck oaverall degradation-ef he baftep&#xfd;-The footnoter, to Table 3.8.6 1 are applicable to Categor,'
A, B3, and C Specificgraviy Fotn eth to Table 3m8.6 1 requires the above mentioned correction forelectrol'Ae level and temperature, with the eXception that level cerrection is notrequired when batter; charging current is2 am;pe On float charge) for Vitalbteisand 4 1.0 amRps for DG b~atterieS.
T-his current provides, in general, aniniainof 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 specificgravity meaur~ement for determining the state Of charge. T-his phenm onidisc-ussr~ed-in !EgE 150 (Ref. 2). Footnote G to Table 32.8.6 1 allRows the floatcharge current to be8 useAd- as an alternate to specific gravity for Up to 31 daysfolwn a bater; recharge.
Within 31 days each connected cell's specificgraviy mus~t be m~easreFd to co4fnfr the state of charge. FollGowig a mninrebatter; recharge (such as equalizing charge that does- not follow a deepdischarge) 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 forG-.enating Stations and Substations."
IEEE Std 450-2002, "IEEERecommended Practice for Maintenance, Testing and ReDlacement ofVented Lead -Acid Batteries for Stationary Applications,"
Institute ofElectrical and Electronics Engineers, Inc.3. IEEE Std 485-1983, "IEEE Recommended Practice for Sizing LarmeLead Storage Batteries for Generatinq Stations and Substations,"
TheInstitute of Electrical and Electronics Engineers, Inc.4. Watts Bar FSAR, Section 8, "Electric Power."Watts Bar-Unit 1B 3.8-80 ATTACHMENT 3Proposed WBN Unit 1 TS Changes (Final Typed)A3-1 DC Sources -Operating 3.8.43.8 ELECTRICAL POWER SYSTEMS3.8.4 DC Sources -Operating LCO 3.8.4Four channels of vital DC and four Diesel Generator (DG) DC electrical powersubsystems shall be OPERABLE.
-- --------------------------
NOTES1. 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 forrequired Vital chargers.
: 3. Spare DG Chargers 1A1, 1B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
: 4. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystem.
APPLICABILITY:
MODES 1, 2, 3, and 4.ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Restore vital battery terminal 2 hourscharger inoperable, voltage to greater than orequal to the minimumestablished float voltage.ANDA.2 Verify vital battery float Once per 12 hourscurrent < 2 amps.ANDA.3 Restore vital battery charger 72 hoursto OPERABLE status.B. One required vital battery B.1 Restore vital battery to 2 hoursinoperable.
OPERABLE status.C. One required vital DC C.1 Restore vital DC channel to 2 hourschannel inoperable for OPERABLE status.reasons other thanCondition A or B.(continued)
Watts Bar-Unit 13.8-24 DC Sources -Operating 3.8.4ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIMED. Required Action and D.1 Be in MODE 3. 6 hoursassociated Completion ANDTime of Condition A, B, orC not met. D.2 Be in MODE 5. 36 hoursE. One required DG battery E.1 Restore DG battery terminal 2 hourscharger inoperable, voltage to greater than orequal to the minimumestablished float voltage.ANDE.2 Verify DG battery float current Once per 12 hours< 1 amp.ANDE.3 Restore DG battery charger to 72 hoursOPERABLE status.F. One required DG battery F.1 Restore DG battery to 2 hoursinoperable.
OPERABLE status.G. One required DG DC G.1 Restore DG DC electrical 2 hourselectrical power subsystem power subsystem toinoperable 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 Gnot met.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify vital battery terminal voltage is greater than or 7 daysequal to the minimum established float voltage.SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 daysequal to the minimum established float voltage.(continued)
Watts Bar-Unit 13.8-25 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.3 Verify for the vital batteries that the alternate feeder 7 daysbreakers to each required battery charger are open.SR 3.8.4.4 Verify correct breaker alignment and indicated power 7 daysavailability for each DG 125V DC distribution paneland associated battery charger.SR 3.8.4.5 Verify each vital battery charger supplies
> 200 amps 18 monthsat greater than or equal to the minimum established float voltage for -4 hours.ORVerify each vital battery charger can recharge thebattery to the fully charged state within 24 hours whilesupplying the largest combined demands of thevarious continuous steady state loads, after a batterydischarge to the bounding design basis eventdischarge state.SR 3.8.4.6 Verify each DG battery charger supplies
> 20 amps at 18 monthsgreater than or equal to the minimum established floatvoltage for > 4 hours.ORVerify each DG battery charger can recharge thebattery to the fully charged state within 24 hours whilesupplying the largest combined demands of thevarious continuous steady state loads, after a batterydischarge to the bounding design basis eventdischarge state.SR 3.8.4.7 -----------------------
NOTES -----------
: 1. The modified performance discharge test inSR 3.8.6.7 may be performed in lieu ofSR 3.8.4.7.2. Credit may be taken for unplanned events thatsatisfy this SR.-----------------------------------
18 monthsVerify battery capacity is adequate to supply, andmaintain in OPERABLE status, the requiredemergency loads and any connected nonsafety loadsfor the design duty cycle when subject to a batteryservice test.Watts Bar-Unit 13.8-26 DC Sources -Operating 3.8.4This Page Intentionally BlankWatts Bar-Unit 13.8-27 DC Sources -Operating 3.8.4This Page Intentionally BlankWatts Bar-Unit 13.8-28 DC Sources -Operating 3.8.4This Page Intentionally BlankWaits Bar-Unit 13.8-29 DC Sources-Shutdown 3.8.53.8 ELECTRICAL POWER SYSTEMS3.8.5 DC Sources -ShutdownLCO 3.8.5Vital DC and Diesel Generator (DG) DC electrical power subsystems shall beOPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems -Shutdown" and to support theDiesel 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 requiredvital chargers.
: 3. Spare DG chargers 1A1, 1 B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
: 4. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystems.
APPLICABILITY:
MODES 5 and 6,During movement of irradiated fuel assemblies.
ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One or more required A.1.1 Declare affected required Immediately vital DC electrical power feature(s) inoperable.
subsystems inoperable.
ORA.2.1. Suspend CORE Immediately ALTERATIONS.
ANDA.2.2 Suspend movement of Immediately irradiated fuel assemblies.
I_ (continued)
Watts Bar-Unit 13.8-30 DC Sources-Shutdown 3.8.5ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. (continued)
ANDA.2.3 Initiate action to suspend Immediately operations involving positivereactivity additions.
ANDA.2.4 Initiate action to restorerequired 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 13.8-31 DC Sources-Shutdown 3.8.5SURVEILLANCE 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, thefollowing SRs are applicable:
In accordance withapplicable SRsSR 3.8.4.1SR 3.8.4.2SR 3.8.4.3SR 3.8.4.4SR 3.8.4.5SR 3.8.4.6SR 3.8.4.7Watts Bar-Unit 13.8-32 Battery Parameters 3.8.63.8 ELECTRICAL POWER SYSTEMS3.8.6 Battery Parameters LCO 3.8.6Battery parameters for required 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within the limits.When associated DC electrical power subsystems and DGs are required to beOPERABLE.
APPLICABILITY:
ACTIONS------------------------
NOTE-Separate Condition entry is allowed for each battery.CONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Perform SR 3.8.4.1.
2 hourswith one or more batterycells float voltage < 2.07 V. ANDA.2 Perform SR 3.8.6.1.
2 hoursANDA.3 Restore affected cell float 24 hoursvoltage >- 2.07 V.B. One required vital battery B.1 Perform SR 3.8.4.1.
2 hourswith float current > 2 amps.ANDB.2 Restore vital battery float 12 hourscurrent to < 2 amps.C. One required DG battery C.1 Perform SR 3.8.4.2.
2 hourswith one or more batterycells float voltage < 2.07 V. ANDC.2 Perform SR 3.8.6.2.
2 hoursANDC.3 Restore affected cell float 24 hoursvoltage > 2.07 V.(continued)
Watts Bar-Unit 13.8-33 Battery Parameters 3.8.6CONDITION REQUIRED ACTION COMPLETION TIMED. One required DG battery D.1 Perform SR 3.8.4.2.
2 hourswith float current > 1 amp.ANDD.2 Restore DG battery float 12 hourscurrent to < 1 amp.E. One required battery ------------------
NOTE ----------
with one or more cells withelectrolyte level less than Required Actions E.1 and E.2 are onlyelectt leelalessthan applicable if electrolyte level was belowminimum established the top of plates.design limits.E.1 Restore electrolyte level to 8 hoursabove top of plates.ANDE.2 Verify no evidence of leakage.
12 hoursANDE.3 Restore electrolyte level to 31 daysgreater than or equal tominimum established designlimits.F. One required battery F.1 Restore battery pilot cell 12 hourswith pilot cell electrolyte temperature to greater than ortemperature 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 hoursbatteries with battery within limits.parameters not within limits.ORMore than one required DGbatteries with batteryparameters not within limits.(continued)
Watts Bar-Unit 13.8-34 Battery Parameters 3.8.6ACTIONS (continued)
CONDITION REQUIRED ACTION COMPLETION TIMEH. 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.OROne required vital batterywith one or more batterycells float voltage < 2.07 Vand float current > 2 amps.OROne required DG batterywith one or more batterycells float voltage < 2.07Vand float current > 1 amp.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 -----NOTE ---------------
Not required to be met when vital battery terminalvoltage is less than the minimum established floatvoltage of SR 3.8.4.1.Verify each vital battery float current is < 2 amps. 7 daysSR 3.8.6.2 -----------------------
NOTE ---------------
Not required to be met when DG battery terminalvoltage is less than the minimum established floatvoltage of SR 3.8.4.2.Verify each DG battery float current is < 1 amp. 7 daysSR 3.8.6.3 Verify each required vital and DG battery pilot cell. 31 daysfloat voltage is > 2.07 V.(continued)
Watts Bar-Unit 13.8-35 Battery Parameters 3.8.6SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.8.6.4 Verify each required vital and DG battery connected 31 dayscell electrolyte level is greater than or equal tominimum established design limits.SR 3.8.6.5 Verify each required vital and DG battery pilot cell 31 daystemperature is greater than or equal to minimumestablished design limits.SR 3.8.6.6 Verify each required vital and DG battery connected 92 dayscell float voltage is > 2.07 V.SR 3.8.6.7 ----------
NOTE---------------
Credit may be taken for unplanned events thatsatisfy this SR.Verify battery capacity is > 80% of the manufacturer's 60 monthsrating when subjected to a performance discharge test or a modified performance discharge test. AND12 months whenbattery showsdegradation, or hasreached 85% of theexpected life withcapacity
< 100% ofmanufacturer's ratingAND24 months whenbattery has reached85% of the expectedlife with capacity? 100% ofmanufacturer's ratingWatts Bar-Unit 13.8-36 Procedures, Programs and Manuals5.75.7 Procedures,
: Programs, and Manuals5.7.2.21 Battery Monitoring and Maintenance ProgramThis Program provides controls for battery restoration and maintenance.
The programshall be in accordance with IEEE Standard (Std) 450-2002, "IEEE Recommended Practice for Maintenance,
: Testing, and Replacement of Vented Lead-Acid Batteries forStationary Applications,"
as endorsed by Regulatory Guide 1.129, Revision 2 (RG), withRG 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 afterconducting discharge tests.2. RG 1.129, Regulatory Position 1, Subsection 2, "References,"
is notapplicable 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 thebattery."
: 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 currenthas stabilized at the charging voltage for three consecutive hourlymeasurements, the battery is near full charge. These measurements shall be made after the initially high charging current decreases sharplyand 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 ofeach 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 batterycells is ? 2.13V when the float voltage of a battery cell has been found tobe < 2.13V;3. Actions to equalize and test battery cells that had been discovered withelectrolyte level below the top of the plates;4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and5. A requirement to obtain specific gravity readings of all cells at eachdischarge test, consistent with manufacturer recommendations.
Watts Bar-Unit 15.0-25b ATTACHMENT 4Proposed WBN Unit I TS Bases Changes (Final Typed)(For Information Only)A4-1 DC Sources-Operating B 3.8.4B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.4 DC Sources -Operating BASESBACKGROUND The station DC electrical power system provides the AC emergency powersystem with control power. It also provides both motive and control power toselected safety related equipment and preferred AC vital bus power (viainverters).
As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1),
the DCelectrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a singlefailure.
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 safetyfunction is to provide control power for engineered safety features equipment, emergency
: lighting, vital inverters, and other safety-related DC poweredequipment for the entire unit. The system capacity is sufficient to supply theseloads and any connected nonsafety loads during normal operation and to permitsafe 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 asingle 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 areassociated 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 theequipment of all other channels so that a single failure in one channel will notcause a failure in another channel.
Each channel consists of a battery chargerwhich supplies normal DC power, a battery for emergency DC power, and abattery board which facilitates load grouping and provides circuit protection.
These four channels are used to provide emergency power to the 120V AC vitalpower system which furnishes control power to the reactor protection system. Noautomatic connections are used between the four redundant channels.
Battery boards I, II, Ill, and IV have a charger normally connected to them andalso have manual access to a spare (backup) charger for use upon loss of thenormal charger.(continued)
Watts Bar-Unit 1B 3.8-54 DC Sources-Operating B 3.8.4BASESBACKGROUND 125V Vital DC Electrical Power Subsystem (continued)
Additionally, battery boards 1, 11, 111, and IV have manual access to the fifth vitalbattery system. The fifth 125V DC Vital Battery System is intended to serve as areplacement 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 ofoperation.
Each of the vital DC electrical power subsystems provide the control power for itsassociated Class 1 E AC power load group, 6.9 kV switchgear, and 480V loadcenters.
The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, theypower the emergency DC lighting system.The vital DC power distribution system is described in more detail in Bases forLCO 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 loadcontinuously for at least 4 hours in the event of a loss of all AC power (stationblackout) without an accident or for 30 minutes with an accident considering asingle failure.
Load shedding of non-required loads will be performed to achievethe required coping duration for station blackout conditions.
Each 125V DC vital battery is separately housed in a ventilated room apart fromits charger and distribution
: centers, except for Vital Battery V. Each subsystem is located in an area separated physically and electrically from the othersubsystem to ensure that a single failure in one subsystem does not cause afailure in a redundant subsystem.
There is no. sharing between redundant Class1 E subsystems, such as batteries, battery chargers, or distribution panels.The batteries for the vital DC electrical power subsystems are sized to producerequired capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the100% design demand. The criteria for sizing large lead storage batteries aredefined in IEEE-485 (Ref.5).The battery cells are of flooded lead acid construction with a nominal specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital battery) the total minimum outputvoltage is 124V and for a 62 cell battery (5th vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or discharging.
Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further chargingper manufacturer's instructions.
Optimal long term performance
: however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfate and selfdischarge.
(continued)
Watts Bar-Unit 1B 3.8-55 DC Sources-Operating B 3.8.4BASESBACKGROUND 1 25V Vital DC Electrical Power Subsystem (continued)
Each Vital DC electrical power subsystem has ample power output capacity forthe steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.
Each batterycharger also has sufficient capacity to restore the battery bank from the designminimum charge to its fully charged state within 12 hours (with accident loadsbeing supplied) following a 30 minute AC power outage and in approximately 36hours (while supplying normal steady state loads following a 2 hour AC poweroutage) (Ref. 6).The battery charger is normally in the float-charge mode. Float-charge is thecondition in which the charger is supplying the connected loads and the batterycells are receiving adequate current to optimally charge the battery.
This assuresthe internal losses of a battery are overcome and the battery is maintained in afully charged state.When desired, the charger can be placed in the equalize mode. The equalizemode is at a higher voltage than the float mode and charging current iscorrespondingly higher. The battery charger is operated in the equalize modeafter a battery discharge or for routine maintenance.
Following a batterydischarge, the battery recharge characteristic accepts current at the current limitof the battery charger (if the discharge was significant, e.g., following a batteryservice test) until the battery terminal voltage approaches the charger voltagesetpoint.
Charging current then reduces exponentially during the remainder ofthe recharge cycle. Lead calcium batteries have recharge efficiencies of greaterthan 91%, so once at least 110% of the ampere-hours discharged have beenreturned, the battery capacity would be restored to the same condition as it wasprior to the discharge.
This can be monitored by direct observation of theexponentially 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 andfield-flash circuits have power supplied from their respective 125V distribution panel. The normal supply of DC current is from the associated charger.
Thebattery provides control and field-flash power when the charger is unavailable.
The charger supplies the normal DC loads, maintains the battery in a fullycharged condition, and recharges (480V AC available) the battery whilesupplying the required loads regardless of the status of the unit. The batteries are physically and electrically independent.
The battery has sufficient capacitywhen fully charged to supply required loads for a minimum of 30 minutesfollowing a loss of normal power. Each battery is normally required to supplyloads during the time interval between loss of normal feed to its charger and thereceipt of emergency power to the charger from its respective DG.Watts Bar-Unit 1B 3.8-56 DC Sources-Operating B 3.8.4BASESAPPLICABLE SAFETY ANALYSESThe initial conditions of Design Basis Accident (DBA) andtransient 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 DCelectrical power for the emergency auxiliaries, and control power for switching during all MODES of operation.
The DG battery systems provide DC power forthe DGs. The OPERABILITY of the DC sources is consistent with the initialassumptions of the accident analyses and is based upon meeting the designbasis of the plant. This includes maintaining the DC sources OPERABLE duringaccident conditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.The DC sources satisfy Criterion 3 of the NRC Policy Statement.
LCOFour 125V vital DC electrical power subsystems, each vital subsystem channelconsisting 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 eachconsisting of a battery, a dual battery charger assembly, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE toensure the availability of the required power to shut down the reactor andmaintain it in a safe condition after an anticipated operational occurrence (AOO)or a postulated DBA. Loss of any DC electrical power subsystem does notprevent the minimum safety function from being performed (Ref. 4).An OPERABLE vital DC electrical power subsystem requires all requiredbatteries and respective chargers to be operating and connected to theassociated DC buses.The LCO is modified by four Notes. Note 1 indicates that Vital Battery V may besubstituted for any of the required vital batteries.
: However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.
Note2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted forrequired vital chargers.
Note 3 indicates that spare DG chargers 1Al, 1 B1, 2A1,or 2B1 may be substituted for required DG chargers.
: However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.
Note 4 indicates that the C-S DG and its associated DCsubsystem may be substituted for any of the required DGs. However, the C-SDG and its associated DC subsystem cannot be declared OPERABLE until it isconnected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.
IWatts Bar-Unit 1B 3.8-57 DC Sources-Operating B 3.8.4BASESAPPLICABILITY The four vital DC electrical power sources and four DG DC electrical powersources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safeplant operation and to ensure that:a. Acceptable fuel design limits and reactor coolant pressure boundarylimits are not exceeded as a result of AOs or abnormal transients; andb. Adequate core coolingis
: provided, and containment integrity and othervital functions are maintained in the event of a postulated DBA.The DC electrical power requirements for MODES 5 and 6 are addressed in theBases for LCO 3.8.5, "DC Sources -Shutdown."
ACTIONS A.1, A.2, A.3, E.1, E.2, and E.3Conditions 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).
TheACTIONS provide a tiered response that focuses on returning the battery to thefully charged state and restoring a fully qualified charger to OPERABLE status ina 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 hours. 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 floatvoltage.
Restoring the battery terminal voltage to greater than or equal to theminimum established float voltage provides good assurance that, within 12hours, 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 currentportion (the second part) of its recharge cycle. The time to return a battery to itsfully charged state under this condition is simply a function of the amount of theprevious discharge and the recharge characteristic of the battery.
Thus there is.good assurance of fully recharging the battery within 12 hours, avoiding apremature shutdown with its own attendant risk.If battery terminal float voltage cannot be restored to greater than or equal to theminimum established float voltage within 2 hours, and the charger is notoperating in the current-limiting mode, a faulty charger is indicated.
A faultycharger that is incapable of maintaining established battery terminal float voltagedoes not provide assurance that it can revert to and operate properly in thecurrent limit mode that is necessary during the recovery period following a batterydischarge event that the DC system is designed for.If the charger is operating in the current limit mode after 2 hours that is anindication that the battery is partially discharged and its capacity margins will bereduced.
The time to return the battery to its fully charged condition in this case isa function of the battery charger capacity, the amount of loads on the associated (continued)
Watts Bar-Unit 1B 3.8-58 DC Sources-Operating B 3.8.4BASESACTIONS DC system, the amount of the previous discharge, and the rechargecharacteristic of the battery.
The charge time can be extensive, and there is notadequate assurance that it can be recharged within 12 hours.Required Actions A.2 and E.2 require that the battery float current be verified lessthan or equal to 2 amps for the vital battery and less than or equal to 1 amp forthe DG battery.
This indicates that, if the battery had been discharged as theresult of the inoperable battery charger, it is now fully capable of supplying themaximum expected load requirement.
The 2 amp value for the vital battery andthe 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 theinitial 12 hour period the battery float current is not less than or equal to 2 ampsfor the vital battery or 1 amp for the DG battery, then this indicates there may beadditional battery problems and the battery must be declared inoperable.
Required Actions A.3 and E.3 limit the restoration time for the inoperable batterycharger to 72 hours. This action is applicable if an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established floatvoltage has been used (e.g., balance of plant non-Class 1 E battery charger).
The72 hour Completion Time reflects a reasonable time to effect restoration of thequalified battery charger to OPERABLE status.B.1 and F.1Conditions B.1 and F.1 represent one channel (subsystem) with one batteryinoperable.
With one battery inoperable, the DC bus is being supplied by theOPERABLE battery charger.
Any event that results in a loss of the AC bussupporting 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 behampered 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 dieselgenerator output circuit breakers, etc.) will likely rely upon the battery.
In additionany DC load transients that are beyond the capability of the battery charger andnormally require the assistance of the battery will not be able to be broughtonline. The 2 hour 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.) areidentified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specificCompletion Times.C.1 and G.1Conditions C.1 and G.1 represent a loss of one DC electrical power subsystem tocompletely respond to an event, and a potential loss of ability to remainenergized during normal operation.
It is therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete lossof DC power to the affected subsystem.
The 2 hour limit is consistent with theallowed time for an inoperable DC distribution subsystem.
If one of the required DC electrical power subsystems is inoperable for reasonsother than Conditions A or B for the vital batteries or Conditions E or F for the DG(continued)
Watts Bar-Unit 1B 3.8-59 DC Sources-Operating B 3.8.4BASESACTIONS DC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accidentcondition.
Since a subsequent worst case single failure could, however, result inthe loss of the minimum necessary DC electrical subsystems to mitigate a worstcase accident, continued power operation should not exceed 2 hours. The 2 hourCompletion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects areasonable time to assess unit status as a function of the inoperable DCelectrical power subsystem and, if the DC electrical power subsystem is notrestored to OPERABLE status, to prepare to effect an orderly and safe unitshutdown.
D.1 and D.2If the inoperable Vital DC electrical power subsystem cannot be restored toOPERABLE status within the required Completion Time, the plant must bebrought to a MODE in which the LCO does not apply. To achieve this status, theplant must be brought to at least MODE 3 within 6 hours and to MODE 5 within36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in anorderly manner and without challenging plant systems.
The Completion Time tobring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).H.1If the DG DC electrical power subsystem cannot be restored to OPERABLEstatus 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 RequiredActions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."
SURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps toensure the effectiveness of the battery chargers, which support the ability of thebatteries to perform their intended function.
Float charge is the condition inwhich the charger is supplying the continuous charge required to overcome theinternal losses of a battery (or battery cell) and maintain the battery (or a batterycell) in a fully charged state while supplying the continuous steady state loads ofthe associated DC subsystem.
On float charge, batterycells will receiveadequate current to optimally charge the battery.
The voltage requirements arebased on the nominal design voltage of the battery and are consistent with theminimum float voltage established by the battery manufacturer.
For example theminimum nominal terminal voltage for the 5th Vital Battery is 136V (62 cells times2.20 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 DGbatteries is 128V (58 cells times 2.20 Vpc). These voltage levels maintain thebattery plates in a condition that supports maintaining the grid life.(continued)
Watts Bar-Unit 1B 3.8-60 DC Sources-Operating B 3.8.4BASESSURVEILLANCE The voltage requirements listed above are based on the critical design voltage ofREQUIREMENTS the battery and are consistent with the initial voltages assumed in the batterysizing calculations.
The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).SR 3.8.4.3Verifying that for the vital batteries that the alternate feeder breakers to eachrequired battery charger is open ensures that independence between the powertrains is maintained.
The 7-day Frequency is based on engineering
: judgment, isconsistent with procedural controls governing breaker operation, and ensurescorrect breaker position.
SR 3.8.4.4This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning
: properly, with all required circuit breakers closed andbuses energized from normal power. The 7 day Frequency takes into accountthe redundant DG capability and other indications available in the control roomthat will alert the operator to system malfunctions.
SR 3.8.4.5 and SR 3.8.4.6These SRs verify the design capacity of the vital and DG battery chargers.
According to Regulatory Guide 1.32 (Ref. 6), the battery charger supply isrecommended to be based on the largest combined demands of the varioussteady state loads and the charging capacity to restore the battery from thedesign minimum charge state to the recharged state, irrespective of the status ofthe unit during these demand occurrences.
Verifying the capability of the chargerto 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 chargerbe capable of supplying 200 amps (20 amps for the DG battery charger) at theminimum established float voltage for 4 hours. Recharging the battery or testingfor a minimum of 4 hours is sufficient to verify the output capability of the chargercan be sustained, that current limit adjustments are properly set and thatprotective devices will not inhibit performance at current limit settings.
The other option requires that each battery charger be capable of recharging thebattery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the statusof the plant during which these demands occur). This level of loading may notnormally be available following the battery service test and will need to besupplemented with additional loads. The duration for this test may be longer thanthe charger sizing criteria since the battery recharge is affected by float voltage,temperature, and the exponential decay in charging current.
The battery isrecharged 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 toperform the test and the other administrative controls existing to ensure adequatecharger performance during these 18 month intervals.
In addition, thisFrequency is intended to be consistent with expected fuel cycle lengths.(continued)
Watts Bar-Unit 1B 3.8-61 DC Sources-Operating B 3.8.4BASESSURVEILLANCE SR 3.8.4.7REQUIREMENTS A battery service test is a special test of battery capability, as found, to satisfy thedesign requirements (battery duty cycle) of the DC electrical power system. Thedischarge rate and test length should correspond to worst case design duty cyclerequirements 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), whichstate 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 modifiedperformance discharge test in lieu of a service test. The modified performance discharge test is a simulated duty cycle consisting of just two rates; the oneminute 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 whichenvelope the duty cycle of the service test. Since the ampere-hours removed bya rated one minute discharge represents a very small portion of the batterycapacity, the test rate can be changed to that for the performance test withoutcompromising the results of the performance discharge test. The batteryterminal voltage for the modified performance discharge test should remainabove the minimum battery terminal voltage specified in the battery service testfor 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 performthe function specified by this Surveillance, for which adequatedocumentation of the required performance is available; and2) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in conjunction withmaintenance required to maintain OPERABILITY or reliability.
Watts Bar-Unit 1B 3.8-62 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-63 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-64 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-65 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-66 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-67 DC Sources-Operating B 3.8.4BASESREFERENCES
: 1. Title 10, Code of Federal Regulations, Part 50, Appendix A, GeneralDesign 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 forNuclear 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 LeadStorage Batteries for Generating Stations and Substations,"
Institute ofElectrical and Electronic Engineers.
: 6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric PowerSystems for Nuclear Power Plants,"
February 1977, U.S. NuclearRegulatory 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, Testingand Replacement of Vented Lead -Acid Batteries for Stationary Applications,"
Institute of Electrical and Electronics Engineers, Inc.10. TVA Calculation EDQ00023620070003, "125V DC Vital Battery SystemAnalysis."
: 11. Regulatory Guide 1.129, "Maintenance Testing and Replacement ofLarge Lead Storage Batteries for Generating Stations and Subsystems,"
U.S. Nuclear Regulatory Commission, February 1978.(continued)
Watts Bar-Unit 1B 3.8-68 DC Sources-Operating B 3.8.4BASESREFERENCES
: 12. iVA Calculation WBN EEB-MS-TI1 1-0062, "125 V DC Diesel Generator (continued)
Control Power System Evaluation"
: 13. Watts Bar FSAR, Section 8.3.1, "AC Power System."Watts Bar-Unit 1B 3.8-69 DC Sources -ShutdownB 3.8.5B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.5 DC Sources -ShutdownBASESBACKGROUND A description of the DC sources is provided in the Bases for LCO 3.8.4, "DCSources -Operating."
APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume that Engineered Safety Feature systems are OPERABLE.
The vital DC electrical power systemprovides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation.
The DGbattery systems provide DC power for the DGs.The OPERABILITY of the DC sources is consistent with the initial assumptions ofthe accident analyses and the requirements for the supported systems'OPERABILITY.
The OPERABILITY of the minimum DC electrical power sources duringMODES 5 and 6, and during movement of irradiated fuel assemblies ensuresthat:a. The plant can be maintained in the shutdown or refueling condition for extended periods;b. Sufficient instrumentation and control capability is available formonitoring and maintaining the plant status; andc. Adequate DC electrical power is provided to mitigate eventspostulated during shutdown, such as a fuel handling accident.
The DC sources satisfy Criterion 3 of the NRC Policy Statement.
(continued)
Watts Bar-Unit 1B 3.8-70 DC Sources -ShutdownB 3.8.5BASESLCO The 125V Vital DC electrical power subsystems, each vital subsystem channelconsisting of a battery bank, associated battery charger, and the corresponding control equipment and interconnecting cabling within the channel; and the DGDC electrical power subsystems, each consisting of a battery, a battery charger,and the corresponding control equipment and interconnecting
: cabling, arerequired to be OPERABLE to support required trains of the distribution systemsrequired OPERABLE by LCO 3.8.10, "Distribution Systems -Shutdown" and therequired DGs required OPERABLE by LCO 3.8.2, "AC Sources-Shutdown."
As aminimum, one vital DC electrical power train (i.e., Channels I and Ill, or II and IV)and two DG DC electrical power subsystems (i.e., 1A-A and 2A-A or 1B-B and2B-B) shall be OPERABLE.
This ensures the availability of sufficient DCelectrical power sources to operate the plant in a safe manner and to mitigate theconsequences of postulated events during shutdown (e.g., fuel handlingaccidents).
The LCO is modified by four Notes. Note 1 indicates that Vital Battery V may besubstituted for any of the required vital batteries.
: However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.
Note 2indicates that spare vital chargers 6-S, 7-S, 8-S or 9-S may be substituted forrequired vital chargers.
Note 3 indicates that spare DG chargers 1A1, 1B1, 2A1,or 2B1 may be substituted for required DG chargers.
: However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.
Note 4 indicates that the C-S DG and its associated DCsubsystem may be substituted for any of the required DGs. However, the C-SDG and its associated DC subsystem cannot be declared OPERABLE until it isconnected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.
(continued)
Watts Bar-Unit 1B 3.8-71 DC Sources -ShutdownB 3.8.5BASES (continued)
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 areavailable;
: b. Required features necessary to mitigate the effects of events that canlead to core damage during shutdown are available; andc. Instrumentation and control capability is available for monitoring andmaintaining the plant in a cold shutdown condition or refueling condition.
The DC electrical power requirements for MODES 1, 2, 3, and 4 are covered inLCO 3.8.4.ACTIONS A.1, A.2.1, A.2.2, A.2.3, and A.2.4If two trains are required by LCO 3.8.10, the remaining train with DC poweravailable may be capable of supporting sufficient systems to allow continuation ofCORE ALTERATIONS and fuel movement.
By allowing the option to declarerequired features inoperable with the associated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with theaffected required features LCO ACTIONS.
In many instances, this option mayinvolve undesired administrative efforts.
Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movementof irradiated fuel assemblies, and operations involving positive reactivity additions).
The Required Action to suspend positive reactivity additions does notpreclude actions to maintain or increase reactor vessel inventory, provided therequired SDM is maintained.
Suspension of these activities shall not preclude completion of actions toestablish a safe conservative condition.
These actions minimize probability ofthe occurrence of postulated events. It is further required to immediately initiateaction to restore the required vital DC electrical power subsystems and tocontinue this action until restoration is accomplished in order to provide thenecessary DC electrical power to the plant safety systems.(continued)
Watts Bar-Unit 1B 3.8-72 DC Sources -ShutdownB 3.8.5BASES (continued)
ACTIONSA.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 foractions requiring prompt attention.
The restoration of the required vital DCelectrical power subsystems should be completed as quickly as possible in orderto minimize the time during which the plant safety systems may be withoutsufficient power.B. 1If one or more required DG DC electrical power subsystem cannot be restored toOPERABLE status in the associated Completion Time, the associated DG maybe 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 REQUIREMENTS SR 3.8.5.1SR 3.8.5.1 requires performance of all Surveillances required by SR 3.8.4.1through SR 3.8.4.7.
Therefore, see the corresponding Bases for LCO 3.8.4 for adiscussion 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 toprovide the required power supply or otherwise rendered inoperable during theperformance of SRs. It is the intent that these SRs must still be capable of beingmet, 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 1B 3.8-73 Battery Parameters B 3.8.6B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.6 Battery Parameters BASESIBACKGROUND This LCO delineates the limits on battery float current, electrolyte temperature, electrolyte level, and cell float voltage, for both the 125V vital DC electrical powersubsystem and the diesel generator (DG) batteries.
A discussion of thesebatteries and their OPERABILITY requirements is provided in the Bases for LCO3.8.4, "DC Sources -Operating,"
and LCO 3.8.5, "DC Sources -Shutdown."
Additional controls for various battery parameters are also provided inSpecification 5.7.2.21, Battery Monitoring and Maintenance Program.The battery cells are of flooded lead acid construction with a nominal specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital battery) the total minimum outputvoltage is 124V and for a 62 cell battery (51h vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or discharging.
Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further chargingper manufacturer's instructions.
Optimal long term performance
: however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfate and selfdischarge as discussed in FSAR, Chapter 8 (Ref. 4).APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident (DBA) and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume Engineered SafetyFeature systems are OPERABLE.
The vital DC electrical power system providesnormal and emergency DC electrical power for the emergency auxiliaries, andcontrol and switching during all MODES of operation.
The DG battery systemsprovide DC power for the DGs.The OPERABILITY of the DC subsystems is consistent with the initialassumptions of the accident analyses and is based upon meeting the designbasis of the plant. This includes maintaining at least one train of DC sourcesOPERABLE during accident conditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.Battery parameters satisfy the Criterion 3 of the NRC Policy Statement.
ILCO Battery parameters must remain within acceptable limits to ensure availability ofthe required DC power to shut down the reactor and maintain it in a safecondition after an anticipated operational occurrence or a postulated DBA.(continued)
Watts Bar-Unit 1B 3.8-74 Battery Parameters B 3.8.6BASESLCO Battery parameter limits are conservatively established, allowing continued (continued)
DC electrical system function even with limits not met. Additional preventative maintenance,
: testing, and monitoring are conducted in accordance withSpecification 5.7.2.21, Battery Monitoring and Maintenance Program.APPLICABILITY The battery parameters are required solely for the support of the associated vitalDC and DG DC electrical power subsystems.
Therefore, battery parameter limitsare 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, A.3, C.1, C.2, and C.3If one required vital battery or one required DG battery has one or more cellvoltage < 2.07 V, the battery is considered degraded.
Within 2 hours verification of the required battery charger OPERABILITY is made by monitoring the batteryterminal voltage (SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state ofcharge by monitoring the battery float charge current (SR 3.8.6.1 or SR 3.8.6.2).
This assures that there is still sufficient battery capacity to perform the intendedfunction.
Therefore, the affected battery is not required to be considered inoperable solely as a result of one or more cells in one battery < 2.07 V andcontinued operation is permitted for a limited period up to 24 hours.Since the Required Actions only specify "perform,"
a failure of SR 3.8.4.1, SR3.8.6.1, SR 3.8.4.2, or SR 3.8.6.2 acceptance criteria does not result in thisRequired 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 SR 3.8.6.1 orSR 3.8.6.2 is failed then there is not assurance that there is still sufficient batterycapacity to perform the intended function and the battery must be declaredinoperable immediately.
B.1, B.2, D.1, and D.2One required vital battery with float current > 2 amps or one required DG batterywith float current > 1 amp indicates that a partial discharge of the battery capacityhas occurred.
This may be due to a temporary loss of a battery charger orpossibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity.
Within 2 hours verification of the required battery chargerOPERABILITY is made by monitoring the battery terminal voltage.If the terminal voltage is found to be less than the minimum established floatvoltage there are two possibilities, the battery charger is inoperable or isoperating in the current limit mode. Conditions A and C addresses chargerinoperability.
If the charger is operating in the current limit mode after 2 hoursthat is an indication that the battery has been substantially discharged and likelycannot perform its required design functions.
The time to return the battery to itsfully 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(continued)
Watts Bar-Unit 1B 3.8-75 Battery Parameters B 3.8.6BASESACTIONS B.1, B.2, D.1 and D.2(continued) discharge, and the recharge characteristic of the battery.
The charge time canbe extensive, and there is not adequate assurance that it can be recharged within 12 hours (Required Actions B.2 and C.2). The battery must therefore bedeclared inoperable.
If the float voltage is found to be satisfactory but there are one or more batterycells with float voltage less than 2.07 V, the associated "OR" statement inCondition H is applicable and the battery must be declared inoperable immediately.
If float voltage is satisfactory and there are no cells less than 2.07V there is good assurance that, within 12 hours, the battery will be restored to itsrecharged condition (Required Actions B.2 and C.2) from any discharge thatmight 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 (thesecond 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 previousdischarge and the recharge characteristic of the battery.
Thus there is goodassurance of fully recharging the battery within 12 hours, 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 stillgreater than 2.07 V and float voltage is found to be satisfactory, this is notindication of a substantially discharged battery and 12 hours is a reasonable timeprior to declaring the battery inoperable.
Since Required Actions B.1 and C.1 only specify "perform,"
a failure of SR3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in the Required Actionnot 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.3With one required vital or DG battery with one or more cells electrolyte levelabove the top of the plates, but below the minimum established design limits, thebattery still retains sufficient capacity to perform the intended function.
Therefore, the affected battery is not required to be considered inoperable solely as a resultof electrolyte level not met. Within 31 days the minimum established designlimits for electrolyte level must be re-established.
With electrolyte level below the top of the plates there is a potential for dryoutand plate degradation.
Required Actions E.1 and E.2 addressed this potential aswell as provisions in Specification 5.7.2.21
.b, Battery Monitoring andMaintenance Program.
They are modified by a Note that indicates they are onlyapplicable if electrolyte level is below the top of the plates. Within 8 hours level isrequired to be restored to above the top of the plates. The Required Action E.2requirement to verify that there is no leakage by visual inspection and theSpecification 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. Theyare performed following the restoration of the electrolyte level to above the top of(continued)
Watts Bar-Unit 1B 3.8-76 Battery Parameters B 3.8.6BASESACTIONS E.1, E.2, and E.3 (continued) the plates. Based on the results of the manufacturer's recommended testing thebattery may have to be declared inoperable and the affected cell(s) replaced.
F.1With one required vital or DG battery with pilot cell temperature less than theminimum established design limits, 12 hours is allowed to restore thetemperature to within limits. A low electrolyte temperature limits the current andpower available.
Since the battery is sized with margin, while battery capacity isdegraded, sufficient capacity exists to perform the intended function and theaffected battery is not required to be considered inoperable solely as a result ofthe pilot cell temperature not met.G.. 1With more than one required vital or more than one DG batteries with batteryparameters not within limits as specified in Conditions A through F there is notsufficient assurance that battery capacity has not been affected to the degreethat the batteries can still perform their required
: function, given that redundant batteries are involved.
With redundant batteries involved this potential couldresult 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 mustbe restored to within limits on at least one subsystem within 2 hours.H.1With one or more batteries with any battery parameter outside the allowances ofthe Required Actions for Condition A, B, C, D, E, F or G sufficient capacity tosupply the maximum expected load requirement is not assured and thecorresponding battery must be declared inoperable.
Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 Vand float current greater than 2 amps for the vital batteries or I amp for the DGbatteries indicates that the battery capacity may not be sufficient to perform theintended functions.
Under these conditions, the battery must be declaredinoperable immediately.
Watts Bar-Unit 1B 3.8-77 Battery Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.1 and SR 3.8.6.2REQUIREMENTS Verifying battery float current while on float charge is used to determine the stateof charge of the battery.
Float charge is the condition in which the charger issupplying the continuous charge required to overcome the internal losses of abattery and maintain the battery in a charged state. The equipment used tomonitor float current must have the necessary accuracy and resolution tomeasure electrical currents in the expected range. The float current requirements are based on the float current indicative of a charged battery.
The 7 dayFrequency is consistent with IEEE-450 (Ref. 2).This SR is modified by a Note that states the float current requirement is notrequired to be met when battery terminal voltage is less than the minimumestablished float voltage of SR 3.8.4.1 or SR 3.8.4.2.
When this float voltage isnot maintained the Required Actions of LCO 3.8.4 ACTION A or E are beingtaken, which provide the necessary and appropriate verifications of the batterycondition.
Furthermore, the float current limit of 2 amps for the vital battery and1 amp for the DG battery is established based on the nominal float voltage valueand is not directly applicable when this voltage is not maintained.
SR 3.8.6.3 and SR 3.8.6.6Optimal long term battery performance is obtained by maintaining float voltagegreater than or equal to the minimum established design limits provided by thebattery manufacturer which is 2.20 Vpc. This corresponds to-a terminal voltageof 128V for the DG batteries, 132V for the vital batteries I through IV and 136Vfor the vital battery V. The specified float voltage provides adequate over-potential, which limits the formation of lead sulfate and self discharge, whichcould eventually render the battery inoperable.
Float voltages in this range orless, but greater than 2.07 Vpc, are addressed in Specification 5.7.2.21.
SRs3.8.6.3 and 3.8.6.6 require verification that the cell float voltages are equal to orgreater than the short term absolute minimum voltage of 2.07V.The Frequency for cell voltage verification every 31 days for pilot cell and 92days for each connected cell is consistent with IEEE-450 (Ref. 2).SR 3.8.6.4The limit specified for electrolyte level ensures that the plates suffer no physicaldamage and maintains adequate electron transfer capability.
The minimumdesign electrolyte level is the minimum level indication mark on the battery celljar. The Frequency is consistent with IEEE-450 (Ref. 2).(continued)
Watts Bar-Unit 1B 3.8-78 Battery Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.5REQUIREMENTS (continued)
This Surveillance verifies that the pilot cell temperature is greater than or equal tothe minimum established design limit (i.e., 60 OF for vital batteries and 50 OF forDG batteries).
Pilot cell electrolyte temperature is maintained above thistemperature to assure the battery can provide the required current and voltage tomeet the design requirements.
Temperature lower than assumed in batterysizing calculations will not ensure battery capacity is sufficient to perform itsdesign function.
The Frequency is consistent with IEEE-450 (Ref. 2).SR 3.8.6.7A battery performance discharge test is a test of battery capacity using constantcurrent.
The test is intended to determine overall battery degradation due to ageand usage.Either the battery performance discharge test or the modified performance discharge test is acceptable for satisfying SR 3.8.6.7;
: however, only the modifiedperformance discharge test may be used to satisfy the battery service testrequirements of SR 3.8.4.7.A modified performance test is a test of the battery capacity and its ability toprovide a high rate, short duration load (usually the highest rate of the dutycycle). This will often confirm the battery's ability to meet the load duty cycle, inaddition to determining its percentage of rated capacity.
Initial conditions for themodified performance discharge test should be identical to those specified for aservice test.It may consist of just two rates; for instance the one minute rate for the battery orthe largest current load of the duty cycle, followed by the test rate employed forthe 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 verysmall portion of the battery capacity, the test rate can be changed to that for theperformance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge testmust remain above the minimum battery terminal voltage specified in the batteryservice 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 bereplaced if its capacity is below 80% of the manufacturer's rating. A capacity of80% shows that the battery rate of deterioration is increasing, even if there isample capacity to meet the load requirements.
Furthermore, the battery is sizedto meet the assumed duty cycle loads when the battery design capacity reachesthis 80% limit.(continued)
Watts Bar-Unit 1B 3.8-79 Battery Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)
SR 3.8.6.7The Surveillance Frequency for this test is normally 60 months. If the batteryshows degradation, or if the battery has reached 85% of its expected life andcapacity is < 100% of the manufacturer's rating, the Surveillance Frequency isreduced to 12 months. However, if the battery shows no degradation but hasreached 85% of its expected life, the Surveillance Frequency is only reduced to24 months for batteries that retain capacity
-> 100% of the manufacturer's ratings.Degradation is indicated, according to IEEE-450 (Ref. 2), when the batterycapacity drops by more than 10% relative to its capacity on the previousperformance test or when it is > 10% below the manufacturer's rating. TheseFrequencies 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 totake credit for unplanned events that satisfy this SR. Examples of unplanned events may include:1) Unexpected operational events which cause the equipment to performthe function specified by this Surveillance for which adequatedocumentation of the required performance is available; and2) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in conjunction withmaintenance required to maintain OPERABILITY or reliability.
REFERENCES
: 1. Watts Bar FSAR, Section 15, "Accident Analysis,"
and Section 6,"Engineered Safety Features."
: 2. IEEE Std 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.3. IEEE Std 485-1983, "IEEE Recommended Practice for Sizing LargeLead Storage Batteries for Generating Stations and Substations,"
TheInstitute of Electrical and Electronics Engineers, Inc.4. Watts Bar FSAR, Section 8, "Electric Power."Watts Bar-Unit 1B 3.8-80 ATTACHMENT 5Plant Specific Verification Regarding the Use of Float Current Monitoring to VerifyBattery State of ChargeA5-1 C.DTECHNOLOGIES, INC.Power Solutions 1400 Union Meeting RoadBlue Bell, PA 19422Phone: (215) 775-1314Fax: (215) 619-7887Sent via Email to: tcwalker(ctva..ov May 30, 2013Mr. Tim WalkerWatts Bar Nuclear PlantTennessee Valley Authority
==Subject:==
Use of Float Current to Determine Operability Revision of Letter dated February 22, 2013
==Dear Tim:==
The following statements are based on a battery temperature of 77F.For the LCUN-33 batteries, when the float current drops to less than or equal to 2 amps,the battery would have been at least 98% recharged.
For the KCR-7 batteries, when the float current drops to less than or equal to 1 amp, thebattery would have been at least 98% recharged.
This relationship will not change as the batteries age.These values of float current are also valid if the float voltage has been adjusted tocompensate for battery temperatures that are above or below 77F. See C&D'sInstallation and Operating Manual (RS-1476) at the following link for recommended temperature compensation factors.http://cdtechno.com/pdf/ref&#xfd;/rs 1476 0610.pdfI hope that this information meets your needs. If you require any additional information, please contact me.Regards,Larry A. CarsonNuclear Product ManagerC&D Technologies, Inc.
ATTACHMENT 6120V AC & 125V DC Vital Plant Control Power System DiagramA6-1 I IL -iI L t o) -) ') )-TIMillI52I T, l 'lFL [-7*rtTh___~ ~ F_ _ -222 10 1_ _ _L4.4 ?i4 2VlF 1 F -F- -f J J-LV ; 2 1 IT 102 LWA I~ ,L J"AwII Li---sLiL ( I T( W (I t1' I I '- EI II I 9 I I .( I; II E , I I (.c[ III I ,- I I L -F-- III "= I I r III I il ~ Ii L --L 2 *all 2 2 2 22,1a~~ll f202222wo99N2222222 22222I a 4 22L( 8 RT-2(1-22
= 221UFSAR AMENDMENT 9WATTS BARFINAL SAFETYANALYSIS REPORTPOWERHOUSE UNITS 1 & 2 KEYDIAGRAM 120V AC & 125V DCVITAL PLANT CONTROL POWERSYSTEMTVA DWG NO. 1-45W700-1 R31FIGURE 8.1-3 ENCLOSURE2 List of Regulatory Commitments Upon implementation of the approved Technical Specification amendment, WVA will meet thefollowing commitments:
: 1. TVA will ensure that the equipment that will be used to monitor float current underSR 3.8.6.1 and SR 3.8.6.2 will have the necessary accuracy and capability to measureelectrical currents in the expected range. Additionally, TVA verifies that the minimumrequired procedural time to measure battery float current will be 30 seconds or asrecommended by the float current measurement instrument manufacturer.
Thisminimum float current measurement time is required to provide a more accurate batteryfloat current reading.2. TVA will ensure that battery room temperature is routinely monitored such that a roomtemperature excursion could reasonably expect to be detected and corrected prior to theaverage battery electrolyte temperature dropping below the minimum electrolyte temperature.
: 3. The cell resistance limits in existing SR 3.8.4.5 will be relocated to the Battery Monitoring and Maintenance Program.
The following cell connection resistance limits are based onbattery vendor recommendations and are listed in the table below:Connection Vital Batteries DG Batteries (pOhm) (pOhm)Inter-cell 80 80Inter-rack 50 50Inter-tier 120 50Terminal Connections 50 504. TVA will ensure that the modified performance discharge test for each DG batterycompletely encompasses the load profile of the battery service test and that itadequately confirms the intent of the service test to verify the DG battery capacity tosupply the design basis load profile.5. Monitoring of battery parameters (i.e., specific
: gravity, electrolyte level, cell temperature, float voltage, connection resistance, and physical condition) will be relocated to thelicensee-controlled program as required and described in TS Section 5.7.2.21, "Programs and Manuals,"
and titled the "Battery Monitoring and Maintenance Program."
: 6. TVA will ensure that plant procedures will require verification of the se.lection of the pilotcell or cells when performing SR 3.8.6.5.7. TVA will revise the UFSAR to include the following, as part of the adoption of TSTF-500, Revision 2.E2-1 of 2
: a. Describe how a 2 percent design margin for the batteries corresponds to a 2 ampfloat current value for the vital battery and 1 amp for the DG battery indicating that the battery is 98 percent charged.b. State how long term battery performance is obtained by maintaining a floatvoltage greater than or equal to the minimum established design limits providedby the battery manufacturer.
: c. Describe how the batteries are sized with correction margins that includetemperature and aging and how these margins are maintained.
: d. State the minimum established design limit for battery terminal float voltage.e. State the minimum established design limit for electrolyte level.f. State the minimum established design limit for electrolyte temperature.
: g. Describe how each battery is designed with additional capacity above thatrequired by the design duty cycles to allow for temperature variations and otherfactors.h. Describe normal DC system operation i.e., powered from the battery chargerswith the batteries floating on the system, and with a loss of normal power to thebattery charger.Comply with RG 1.129 Revision 2, Maintenance,
: Testing, and Replacement ofVented Lead-Acid Storage Batteries for Nuclear Power Plants which endorsesIEEE 450-2002.
E2-2 of 2}}

Revision as of 08:06, 4 July 2018

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 Tennessee Valley Authority icon.png
Issue date: 08/28/2013
From: Shea J W
Tennessee Valley Authority
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
WBN-TS-12-07
Download: ML13248A250 (137)
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Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402August 28, 201310 CFR 50.90ATTN: Document Control DeskU.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1Facility Operating License No. NPF-90NRC 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 LicenseNo. 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, "DCSources-Shutdown,"

and TS 3.8.6, "Battery Cell Parameters."

This amendment requestincludes changes consistent with both Technical Specifications Task Force (TSTF) changetraveler 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 thatare appropriate to the WBN Unit 1 design, because the direct current (DC) electrical powerdistribution system referenced in the model application is significantly different the system thatexists at Watts Bar. Furthermore, due to these differences, TVA has not utilized the modelapplication for TSTF-500, but has provided plant specific justifications for the related TSTF-500changes being proposed in this LAR. In addition to the TSTF-360 and TSTF-500 relatedchanges, editorial and clarification changes are being made to TS 3.8.4, 3.8.5, and 3.8.6.Enclosure 1 to this letter provides a description, technical evaluation, regulatory evaluation, andenvironmental 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 3and 4 to the enclosure provide the existing TS and Bases pages retyped with the proposedchanges incorporated.

Prin~ted on recycled paper I c c U.S. Nuclear Regulatory Commission Page 2August 28, 2013Attachment 5 to the enclosure contains a letter from the battery manufacturer verifying theacceptability of using float current monitoring as a reliable and accurate indication of thestate-of-charge of the battery, which will hold true over the life of the battery.

Attachment 6 tothe enclosure is a schematic diagram of the WBN 120V AC and 125V DC Vital Plant ControlPower System for information only.TVA requests approval of this TS change by August 30, 2014, and will implement revised TSswithin six months of NRC approval.

TVA has determined that there are no significant hazards considerations associated with theproposed 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 Boardhave 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 andenclosures to the Tennessee State Department of Environment and Conservation.

Enclosure 2 provides the list of regulatory commitments associated with this LicenseAmendment 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 the28th day of August 2013.Respe u y,J. .hkeaVi e P \sident, Nuclear Licensing Enclosure cc: See Page 3 U.S. Nuclear Regulatory Commission Page 3August 28, 2013

Enclosures:

1. Evaluation of Proposed Change2. List of Regulatory Commitments cc (Enclosures):

NRR Project Manager -Watts Bar Nuclear Plant, Unit 1NRC Regional Administrator

-Region IINRC Resident Inspector

-Watts Bar Nuclear Plant, Unit 1NRC Resident Inspector

-Watts Bar Nuclear Plant, Unit 2Director, Division of Radiological Health -Tennessee State Department of Environment and Conservation ENCLOSURE 1TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT UNIT 1EVALUATION 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 BatteryState of Charge6. 120V AC & 125V DC Vital Plant Control Power System DiagramE1-1 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 1Technical Specification (TS) requirements related to direct current (DC) electrical systems inTS 3.8.4, "DC Sources -Operating,"

TS 3.8.5, "DC Sources -Shutdown,"

and TS 3.8.6, "BatteryCell Parameters."

In addition, a new "Battery Monitoring and Maintenance Program" is beingproposed 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 batterycharger and alternate testing criteria in the applicable Surveillance Requirements (SRs). Theproposed changes also include the relocation of a number of SRs in TS 3.8.4 that performpreventive maintenance on the safety-related batteries to a licensee-controlled program.

Theproposed 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, andelectrolyte temperature to TS 3.8.6. Specific SRs are also being proposed for verification ofthese parameters.

A new program is being proposed as TS 5.7.2.21 for the maintenance and monitoring of stationbatteries.

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 toTSTF-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 fromthat which exists at Watts Bar, the proposed TS changes are based on those TSTF-360 andTSTF-500 changes that are appropriate to the WBN Unit 1 design. Furthermore, due to thesedifferences, TVA has not utilized the model application for TSTF-500, but has provided plantspecific justifications for the related TSTF-500 changes being proposed in this LAR. In additionto the TSTF-360 and TSTF-500 related changes, editorial and clarification changes are beingmade 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 assome clarification changes to these three Technical Specifications are being proposed toimprove the use and readability of TSs 3.8.4, TS 3.8.5, and TS 3.8.6.E1-2 of 29 2.0 DETAILED DESCRIPTION

Background

Vital 125V DC Control Power SystemThe Vital 125 volt (V) DC Control Power System is a Class 1 E DC electrical power system(Reference

4) that provides control power to the emergency alternating current (AC) powersystem (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 1and 2. Each channel consists of a battery charger that supplies normal DC power, a battery foremergency DC power, and a battery board to facilitate load grouping and provide circuitprotection.

Loads are assigned according to their divisional requirements and are shared with WBN Units 1and 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) andTrain 1 B and 2B (load group B) and are primarily associated with the ESF systems.

One loadgroup can mitigate a design basis accident on one unit and safely shut down the other unitassuming 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 Vshutdown boards are provided by Channels I and III and for load group B, by Channels IIand 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 useupon loss of the normal charger.

Each pair of spare chargers is mechanically interlocked suchthat 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 DCVital Battery System is intended to serve as a replacement for any one of the four 125V DC vitalbatteries during testing, maintenance, and outages with no loss of system reliability under anymode 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 differssubstantially from the standard plant design assumed in TSTF-500 and the model NRC SafetyEvaluation for the TSTF. The DC System design referenced in TSTF-500 consists of twoindependent and redundant DC power trains per unit. As discussed above, the WBN Unit 1125V DC Vital Control Power Systems consists of four redundant channels that are shared withWBN 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 360and 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. TheDC electrical power system is designed to have sufficient independence, redundancy, andtestability 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. Incase of loss of normal power to the battery charger, the DC load is automatically powered fromthe station batteries.

E1-3 of 29 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 theother subsystem to ensure that a single failure in one subsystem does not cause a failure in aredundant 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 inthe 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 andother factors.Each DC electrical power subsystem battery charger has ample power output capacity for thesteady state operation of connected loads required during normal operation, while at the sametime maintaining its battery bank fully charged.

Each battery charger also has sufficient excesscapacity to restore the battery from the design minimum charge to its fully charged state whilesupplying normal steady state loads.Each battery charger is normally in the float-charge mode. Float-charge is the condition inwhich the charger is supplying the connected loads and the battery cells are receiving adequatecurrent to optimally charge the battery.

The purpose of the float-charge is to overcome theinternal 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 eachchannel.

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 DCduring an equalizing charge period (all loads can tolerate the 140 volt equalizing voltage).

Thecharger supplies normal steady state DC load demand on the battery board and maintains thebattery in a charged state. Normal recharging of the battery from the design discharged condition can be accomplished in approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (with accident loads being supplied) following a 30-minute AC power outage and in approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (with normal loads beingsupplied) following a 4-hour AC power outage. The battery chargers, including the sparechargers if in service, are automatically loaded on the diesel generators following a loss ofoffsite 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 assignedchannels.

It can also be substituted for or operate in parallel with the normal charger in thatchannel.Alternating current power for each charger is derived from the station auxiliary power system viatwo 480V AC 3-phase circuits which are physically and electrically independent.

Each circuithas 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 transferswitches are mechanically interlocked to prevent closing switches in a manner to parallel bothfeeds. The alternate 480V feeder breakers are verified open in accordance with the TSs. Eachcharger 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 powerto 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 toa nominal 125V DC output having a rated capacity of 200 amperes.

Over this output currentE1-4 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 ratedoutput;(4) protective devices which prevent a failed charger from discharging its associated batteryand 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 anover-voltage condition.

The chargers normally operate in the float mode at 135V DC for Batteries I through IV and138.5V DC for Battery V. The maximum equalizing voltage for Batteries I through IV is140V DC when connected to the distribution system. The system configuration, usingsubstitution of Battery V, permits off-line equalization at higher than normal values.Emer-gency DC SupplyThe emergency supply of DC current to each distribution board is from its associated vitalbattery.

There are five vital batteries for the plant; one associated with each channel and VitalBattery V, which serves as a temporary replacement for Vital Battery 1, 11, 111 or IV. Thesebatteries are physically and electrically independent.

The vital batteries supply the entire plantDC 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 unitscontinuously for 30 minutes.

The batteries also have the capability to supply the essential loadsrequired to maintain the plant in a safe shutdown condition for four hours following a loss of allnormal and standby AC power, but no accident (i.e., a station blackout).

Each battery isnormally required to supply loads only during the time interval between loss of normal feed to itscharger and the receipt of emergency power to the charger from the standby diesel generator (DG).Diesel Generator 125V DC Control SystemA 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 DCcontrol power and field-flash when the charger is unavailable.

If 480V AC is available, thecharger supplies the normal DC loads, maintains the battery in a fully charged condition, andrecharges 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 areungrounded 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 aloss of normal power. Battery capacity design requirements consider minimum required voltagefor loads and the effects of aging and ambient temperature.

Each battery is normally required tosupply loads only during the time interval between loss of normal feed to its charger and thereceipt 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 of105V 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.

Eachcharger maintains a float voltage of approximately 130V DC on the associated battery boardwith the battery connected to the board and is capable of maintaining 135V DC during anequalizing 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 ACsource from two respective 480V AC Diesel Generator Auxiliary Boards. If the normal charger isunavailable, the alternate charger is selected by the 125V DC transfer switch included in theassembly.

The charger is a solid-state type which converts a 3-phase 480V AC input to anominal 125V DC output. The DC output voltage will vary no more than +/- 1.0% for a supplyvoltage 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 modeat 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 ChangesThe 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) foran 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 alicensee-controlled program.

This focuses TS requirements on the analysis basis safetyfunction of the battery.The proposed TS changes are as following.

  • Revise 3.8.4, "DC Sources Operating" to add Conditions for inoperable battery chargersand inoperable batteries, and relocate SRs on battery corrosion, connection resistance, and visual inspection, to the new Battery Monitoring and Maintenance Program.

Allowuse of the Modified Performance testing to satisfy SRs for Service Testing andPerformance Testing." Revise the list of TS 3.8.4 SRs in TS 3.8.5, "DC Sources -Shutdown,"

that must be metto 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 meetCategory A and B limits to the new Battery Monitoring and Maintenance Program.E1-6 of 29 Retain Category C limits for cell float voltage and electrolyte level in new proposedTS. 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 inAttachment 1 to this Enclosure 2.2 Need for Proposed ChangesWBN Unit 1 Technical Specifications were initially written and approved by the NRC based onthe original revision of NUREG-1431, "Standard Technical Specifications

-Westinghouse Plants."

Since the issuance of Revision 0, many changes have been made to NUREG-1431 toenhance,

improve, and clarify the Technical Specifications.

One area of enhancements andimprovements is in the area of DC sources, TSs 3.8.4, TS 3.8.5, and TS 3.8.6. WBN Unit 1 hasnot previously updated the WBN Unit 1 Technical Specification to include two of the majorchanges 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 andclarification 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 asdescribed below.3.1.1 LCO 3.8.4 NotesThe 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 vitalchargers.
3. Spare DG Battery Chargers 1Al, 1 B1, 2A1, or 2B1 may be substituted for requiredDG chargers.
4. The C-S DG and its associated DC electrical power subsystem may be substituted forany of the required DGs and their associated DC electrical power subsystem.

Technical Justification for LCO 3.8.4 Note changesExisting Note 2 is renumbered Note 4. New Notes 2 and 3 allow substitution of the spare vitalbattery and DG battery chargers for the required battery chargers.

The spare battery chargersare fully qualified and appropriately sized to perform their design safety function as those beingreplaced.

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

E1-7 of 29 3.1.2 TS 3.8.4 Actions A and EThe proposed change adds new Conditions A and E to address the conditions in which onerequired vital battery charger on one channel (Condition A) or one required DG battery chargeron 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 <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> in current Required Actions A. 1and C.1 to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in proposed Required Actions A.3 and E.3, provided that battery terminalvoltage is restored to greater than or equal to the minimum established float voltage within2 hours (Required Actions A.1 and E.1), and battery float current is verified to be less than orequal to 2 amps for the vital battery and 1 amp for the DG battery once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Required Actions A.2 and E.2).Technical Justification for TS 3.8.4 Actions A and E changesNew 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) isinoperable.

The term "required" is added since there are spare chargers, as stated anddiscussed in proposed Notes 2 and 3 (i.e., not all installed chargers are required by the LCO tobe operable).

There are three associated Required Actions for new Conditions A and E. TheRequired Actions provide a tiered response that focuses on returning the battery to the fullycharged 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 thanor equal to the minimum established float voltage within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. Required Actions A.2 and E.2require the vital battery float current to be verified to be < 2 amps and the DG battery floatcurrent to be verified to be < 1 amp once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Required Actions A.3 and E.3 requirethe battery charger to be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.New Required Actions A.1 and E.1 provide assurance that a battery discharge is terminated byrequiring that the battery terminal voltage be restored to greater than or equal to the minimumestablished float voltage within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The battery charger, in addition to maintaining thebattery operable, provides DC control power to AC circuit breakers and thus supports therecovery 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 operablestatus or for reestablishing an alternate means of restoring battery terminal voltage to greaterthan or equal to the minimum established float voltage.

This provides assurance that thebattery will be restored to its fully charged condition from any discharge that might haveoccurred due to the battery charger being inoperable.

At the end of the 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, a terminalvoltage of at least the minimum established float voltage provides indication that the battery ison 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 <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, the battery float current beverified to be < 2 amps for the vital battery and < 1 amp for the DG battery.

This confirms that ifthe battery has been discharged as the result of an inoperable battery charger, it had beenrecharged.

If at the expiration of the 12-hour period, the float current for the vital battery isgreater 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 toperform its safety function.

New Required Actions A.3 and E.3 require restoring the inoperable battery charger to operablestatus within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The presumptions that: (1) the DC bus remains energized; (2) thebattery discharge is terminated based on restoration of the battery terminal voltage (NewE1-8 of 29 Required Actions A.1 and E.1); and (3) the battery is fully recharged based upon battery floatcurrent (New Required Actions A.2 and E.2), establish a basis for extending the restoration timefor an inoperable battery charger beyond the existing 2-hour CT to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (New RequiredActions A.3 and E.3).3.1.3 TS 3.8.4 Actions B and FThe proposed change would add new Actions B and F, which would apply when one requiredvital battery on one channel or one required DG battery on one train is inoperable.

Theproposed Required Action would state that the battery must be restored to operable statuswithin 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.Technical Justification for TS 3.8.4 Actions B and F changesWith batteries on one channel or train inoperable, the DC bus is being supplied by an operablebattery charger(s).

Any event that results in a loss of the AC bus supporting the batterycharger(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 anddiesel 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 thelimiting 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 allowedRequired Actions and associated CTs. In addition, these proposed Actions are consistent withcurrent TS 3.8.4 Actions A and C, which currently apply to the condition of one inoperable vitalbattery 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 "forreasons other than Condition A or B" is added to renumbered Condition C. Existing Condition Cis renumbered to Condition G and the exception "for reasons other than Condition E or F" isadded to renumbered Condition G. Existing Condition B is renumbered to Condition D and thephrase "of Condition A" is changed to "of Condition A, B, or C." Existing Condition D isrenumbered 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 changesThe proposed change is editorial in nature and will not result in new requirements or changeoperational restrictions or flexibility.

The Conditions are renumbered and the additional wordsadded to the Conditions due to the addition of the proposed Actions A, B, E, and F, asdescribed in subsections 3.1.2 and 3.1.3 above.3.1.5 SR 3.8.4.1 and SR 3.8.4.2SR 3.8.4.1The 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 thanor equal to the minimum established float voltage."

The frequency of 7 days remainsE1-9 of 29 unchanged.

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

The frequency of 7 days remains unchanged.

The value for theminimum established float voltage is removed from this TS and controlled by the newTS 5.7.2.21 (described below in section 3.4).Technical Justification for SR 3.8.4.1 and SR 3.8.4.2 changesThis change removes specific terminal voltage criteria currently identified in SR 3.8.4.1 andSR 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 terminalvoltage while the system is on a float charge to ensure the effectiveness of the battery chargeris not degraded.

The battery terminal voltage selected by the battery manufacturer is theminimum voltage which ensures an optimum charging voltage is applied to the battery.

Theminimum established float voltage will maintain the battery plates in a condition that supportsoptimizing battery grid life. Maintaining this voltage limit ensures that the battery will be capableof 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 thosethat represent the lowest voltage cells in the battery.

This ensures that the other cells should beabove 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 3.8.4.10The 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 physicaldamage),

SR 3.8.4.8 (remove visible corrosion and ensure that connections are clean andtight), and SR 3.8.4.9 and SR 3.8.4.10 (verification of connection resistance for vital andDG 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, andSR 3.8.4.10 changesThe 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 theSurveillance 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 batteryterminals for signs of corrosion, as required by SR 3.8.4.5, SR 3.8.4.6, SR 3.8.4.7 andSR 3.8.4.8, to ensure that connections are clean and tight are generally considered a routinepreventive 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 thepost and the connector).

However, visual .inspection of the battery terminals alone does notprovide an indication of a battery's capability to perform its design function.

Therefore, TVAconcludes that these activities are preventive maintenance and that the parameters can beadequately controlled in the new TS 5.7.2.21.

El-10 of 29 With regard to the resistance verifications of SR 3.8.4.9 and SR 3.8.4.10, the existing valuesrepresent limits at which some action should be taken, not necessarily when the operability ofthe 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.

Betweensurveillances, the resistance of each battery inter-cell connection varies independently from allthe others. Some of these connection resistance values may be higher or lower than others, andthe 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, theseactivities are more appropriately controlled under the proposed Battery Monitoring andMaintenance Program (TS 5.7.2.21).

3.1.7 SR 3.8.4.11 and 12The 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 capableof supplying the minimum charging current at the minimum established float voltage for at least4 hours. The second test allowance (SR 3.8.4.5 and SR 3.8.4.6 second test allowance) addsacceptance criteria as to the time required to recharge the battery (24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) and clarifies thatduring the recharging, the charger must also be supplying the largest combined demands of thevarious 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 basisevent discharge state, in lieu of the current requirement to start the test after a service orcapacity discharge test. The proposed change also deletes the Notes for SR 3.8.4.11 andSR 3.8.1.12.

Technical Justification for TS SR 3.8.4.11 and SR 3.8.4.12 changesRenumbering 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 batterycharger current requirements for each DC source, and its purpose is to verify the designcapacity of each battery charger.

The voltage requirements are based on the battery chargervoltage level after a response to a loss of AC power. Battery manufacturers establish thisvoltage limit to provide the optimum charge on the battery and to maintain the battery plates in acondition that supports maintaining the battery grid life. Maintaining this voltage limit shouldensure 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 torepresent the lowest voltage cells in the battery.

This should ensure that the other cells areabove 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."El-11 of 29 The proposed alternate test method is revised to:"Verify each vital [DG] battery charger can recharge the battery to the fully charged state within24 hours while supplying the largest combined demands of the various continuous steady stateloads, 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 notbe sufficient to demonstrate battery charger capability following the battery service test orcapacity discharge test and may need to be supplemented with additional loads. The duration ofthis test may be longer than the charger sizing criteria since the battery recharge is affected byfloat voltage, temperature, and the exponential decay in charging current.

If each batterycharger is capable of recharging its respective battery within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> while supplying thelargest combined demands of the various continuous steady state loads, after a batterydischarge to the design minimum discharge state, the proposed alternate testing criteria wouldsatisfy 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 toeliminate 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 betaken 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 inorder to perform the two SRs for the normal chargers.

The spare chargers are allowed tosubstitute for the normal chargers, as described in Section 3.1.1 above. Therefore, norestriction on performing these SRs during Modes 1, 2, 3, and 4 are required and at least onemethod of verifying charger OPERABILITY can be performed in MODE 1, 2, 3, or 4 withoutaffecting plant safety.3.1.8 SR 3.8.4.13The 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 byperforming the modified performance discharge test instead of the service discharge test.Technical Justification for TS SR 3.8.4.13 changeTVA proposed revising Note 1 to SR 3.8.4.13 (new SR 3.8.4.7) to eliminate the "once per 60months" limitation for satisfying the SR by performing the modified performance discharge testinstead 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 themodified performance discharge test for the vital batteries completely encompasses the loadprofile of the battery service discharge test. TVA commits to confirming that the modifiedperformance discharge test for the DG batteries completely encompasses the load profile of thebattery service discharge test.El-12 of 29 3.1.9 SR 3.8.4.14The proposed change moves SR 3.8.4.14 to TS 3.8.6, and renumbers it as SR 3.8.6.7.

Inaddition, 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 changeThis change moves SR 3.8.4.14 to TS 3.8.6 and renumbers it as SR 3.8.6.7.

In addition, theNote restriction for performing the SR in Mode 1, 2, 3, or 4, which only applies to the vitalbatteries, is being deleted.

The purpose of SR 3.8.4.14 is to verify that the battery capacity forboth the vital and DG batteries meet design requirements.

Therefore, consistent with therequirements of SR 3.0.1, these surveillances are moved to TS 3.8.6. The proposed SRcontains 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 inorder to determine the state-of-health of the safety-related batteries given the expected servicelife. The surveillance frequencies are appropriate given the condition of the battery, allowssufficient time for corrective actions to be taken, and is consistent with the safety significance ofsafety-related batteries.

The restriction for performing the test on the vital batteries is eliminated since WBN has a sparebattery 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 thenormal batteries.

Therefore, no restriction on performing this SR (new SR 3.8.6.7) duringModes 1, 2, 3, and 4 is required.

3.2 TS 3.8.5, DC Sources -ShutdownTVA proposes to revise TS 3.8.5 LCO Notes, Conditions, Required

Actions, and SRs asdescribed below.3.2.1 LCO 3.8.5 LCO NotesThe 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 vitalchargers;
3. Spare DG Battery Chargers WA1, 1 B1, 2A1, and 2B1 may be substituted for required DGchargers; and4. The C-S DG and its associated DC electrical power subsystem may be substituted forany of the required DGs and their associated DC electrical power subsystem.

Technical Justification for TS 3.8.5 LCO Notes changeExisting Note 2 is renumbered Note 4. New Notes 2 and 3 allow substitution of the spare vitalbattery and DG battery chargers for the required battery chargers.

The spare battery chargersare fully qualified and appropriately sized to perform their design safety function as those beingE1-13 of 29 replaced.

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

3.2.2 TS 3.8.5 Required Action A.2.4 and Condition BRequired Action A.2.4 is modified to clarify that the Required Action is specific to the vitalbattery subsystem and not the DG electrical power subsystem.

The proposed change adds theword "vital,"

such that the Required Action reads "...restore required vital DC electrical powersubsystems 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 powersubsystem inoperable.

Technical Justification for TS 3.8.5 Required Action A.2.4 and Condition B changeCurrent 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 actualCondition.

The Condition B addition ensures that proper actions are taken when more than oneDG DC electrical power subsystems are required by the LCO and more than one areinoperable.

The current Condition only applies to a single inoperability

-no Actions are providedwhen 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, itsassociated 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 3.8.5.1The proposed change would modify SR 3.8.5.1 to reflect the changes previously described inSection 3.1. Specifically, the SR numbers have been changed to reflect the deletion fromTechnical 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 changeSR 3.8.5.1 is modified to be consistent with the proposed changes to TS 3.8.4. RevisedSR 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 certainSRs, as allowed in the Note to the SR, identifies the same SRs as are in the current Note thatare remaining in TS 3.8.4.The proposed change meets 10 CFR 50.36 requirements for surveillances by ensuring that thenecessary quality of systems and components is maintained and that the LCOs will be met.El-14 of 29 3.3 TS 3.8.6, Battery Parameters TVA proposes to revise TS 3.8.6 LCO, Conditions, Required

Actions, and SRs. As part ofthese changes, battery float current monitoring is replacing specific gravity monitoring and anew TS Battery Monitoring and Maintenance Program is being added into TS Chapter 5.3.3.1 TS 3.8.6 TitleThe proposed change revises the title of TS 3.8.6 from "Battery Cell Parameters" to "BatteryParameters."

Technical Justification for TS 3.8.6 Title changeThe 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 natureand will not result in new requirements or change operational restrictions or flexibility.

3.3.2 TS 3.8.6 LCOThe proposed change revises TS 3.8.6 LCO to delete the word "cell" and to require that thebattery 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 LCOstatement.

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

The change to add the word "required" is consistent with TS 3.8.4 and TS 3.8.5, in thatLCO 3.8.4 Note 1 allows the alternate battery (Vital Battery V) to be used to meet theLCO requirements.

Thus, the word "required" is added for consistency when there are moreinstalled components than are required to meet the LCO.The change deleting the reference to Table 3.8.6-1 is consistent with changes described andjustified below in Section 3.3.4 below.Therefore, these changes are editorial in nature.3.3.3 TS 3.8.6 ACTIONS NoteThe proposed change deletes the term "bank" from the ACTIONS Note. Specifically, theACTIONS Note will be changed from "Separate Condition entry is allowed for each batterybank" to "Separate Condition entry is allowed for each battery."

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

Conditions.

EI-15 of 29 3.3.4 TS 3.8.6 Table 3.8.6-1The proposed change deletes Table 3.8.6-1, "Battery Cell Parameter Requirements" and movesthe 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 tolicensee-controlled documents.

Technical Justification for TS 3.8.6 Table 3.8.6-1 changesTS 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 innew 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 aand b) and the Required Actions associated with restoring the cell parameters to within theselimits (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 toplace this information in the licensee-controlled program.

The Category A and B values ofTS 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 restoredeficient 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 theregulatory requirements of 10 CFR 50.65. This relocation will continue to assure that thebattery is maintained at current levels of performance, and that operators appropriately focus onmonitoring the battery parameters for degradation.

TVA proposes relocating the Category C specific limiting values of TS Table 3.8.6-1 for thebattery electrolyte levels to the Battery Monitoring and Maintenance Program.

However, newTS 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. TVAproposes relocating the electrolyte temperature and level criteria (i.e., the minimum established design limits) to the Battery Monitoring and Maintenance Program.

This program will becontrolled as required by new TS 5.7.2.21, and TVA commits to place this information in alicensee-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 provideTVA with added flexibility to monitor and control this limit at values directly related to thebattery's ability to perform its assumed function.

TVA also proposes relocating the Category C specific limiting values of TS Table 3.8.6-1 forspecific gravity to the Battery Monitoring and Maintenance Program.

However, in lieu ofrelocating the specific
gravity, TVA proposes to use float current monitoring to measure batterystate of charge. This method is currently allowed by Table 3.8.6-1 Note c for up to 31 daysfollowing 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, thebatteries are at least 98% recharged.

TVA therefore commits to maintain a 2% design marginto provide assurance that the batteries are fully charged when the above float current limits areEl-16 of 29 reached.

In addition, TVA commits to revise the UFSAR to provide a description of thiscapability.

For replacement batteries of a different model/size and/or manufacturer, float currentlimit 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 monitorfloat current under new SR 3.8.6.1 and SR 3.8.6.2 (which are described below inSection 3.3.12) will have the necessary accuracy and capability to measure electric currents inthe 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 theTS Battery Monitoring and Maintenance Program.3.3.5 TS 3.8.6 Actions A and CThe proposed change adds new TS 3.8.6 Actions A and C to address what is currently theCategory C limit for float voltage in TS Table 3.8.6-1.

Current TS 3.8.6 Action B requires thebattery to be immediately declared inoperable when this value is not met.Technical Justification for TS 3.8.6 Actions A and C changesTVA proposes deleting Action B, as it refers to the Category C limit for float voltage, and addingnew TS 3.8.6 Actions A and C to address what was formerly the Category C limit for floatvoltage 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 than2.07V. Actions A and C provide the Required Actions for the condition of a degraded batterycell. The Required Actions are to perform within 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s: (a) SR 3.8.4.1 or SR 3.8.4.2 -verifythe 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 eachbattery's float current is less than or equal to 2 amps for the vital batteries and less than 1 ampfor the DG batteries (Required Actions A.2 and C.2, respectivelyl).

The above actions ensurethat there is still sufficient capacity for the battery to perform its intended function.

Provided theabove actions are met, Required Actions A.3 and C.3 will allow continued operation for up to24 hours 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'sUFSAR provides reasonable assurance that the value will be appropriately maintained by TVAto accurately reflect the design of the plant.3.3.6 TS 3.8.6 Actions B and DThe 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 thecurrent 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 changeTVA proposes deleting Action B, as it refers to the category C limit on specific

gravity, andadding new TS 3.8.6 Actions B and D to address battery state of charge. These new Actionsare applicable when one required vital battery (Action B) is found with float current greater than2 amps or one required DG battery (Action D) is found with float current greater than 1 amp. Afloat current of greater than 2 amps for the vital batteries and 1 amp for DG batteries providesindication that a partial discharge has occurred.

The Required Actions (Required Actions B.1E1-17 of 29 and D.1) are to verify within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> that the battery terminal voltage is greater than or equal tothe 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 cellswith voltage less than 2.07V, Required Actions B.2 and D.2 require that within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> thebattery be restored to its fully-charged condition (i.e., < 2 amps for the vital battery and < 1 ampfor the DG battery) from any discharge that might have occurred due to a temporary loss of thebattery 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 thebattery charger is operating in the current limit mode for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, it indicates that the battery hasbeen substantially discharged and likely cannot perform its required design functions.

In thiscase, new Condition H would be entered.

This Action requires the associated battery to beimmediately declared inoperable, which is consistent with current Action B.3.3.7 TS 3.8.6 Action EThe proposed change adds new TS 3.8.6 Action E to address the level of the electrolyte in acell. Current TS 3.8.6 Action A provides the actions when electrolyte level does not meet thecategory A and B limits, and requires verification the level is above the top of the plates within1 hour and to restore the level to within limits in 31 days.Technical Justification for TS 3.8.6 Action E changeTVA proposes adding new TS 3.8.6 Action E to address the electrolyte level in a cell. This newAction E is applicable when one required vital or DG battery is found with one or more cells withan electrolyte level less than the minimum established design limits. If the electrolyte level isabove 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 itsintended safety function and could be considered operable.

With the electrolyte level below thetop of the plates, there is a potential for dry-out and plate degradation.

New RequiredActions 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 <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> (Required Action E. 1), ensure that the cause of the loss of the electrolyte level is not due to a leak in thebattery cell jar within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Required Action E.2), and equalize and test the battery cells thathave been discovered with an electrolyte level below the top of the plates in accordance withthe 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. Inaddition, Required Action E.3 requires the battery electrolyte level to be restored to greater thanor equal to the minimum established design limits within 31 days.3.3.8 TS 3.8.6 Action FThe proposed change adds new TS 3.8.6 Action F which applies to a battery found with a pilotcell electrolyte temperature less than the minimum established design limit. Current TS 3.8.6Action B requires the battery to be immediately declared inoperable when a pilot cell electrolyte temperature is not within limits.EI-18 of 29 Technical Justification for TS 3.8.6 Action F changeTVA proposes adding new TS 3.8.6 Action F which applies to a battery found with a pilot cellelectrolyte 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 isapplicable 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.1requires the electrolyte pilot cell temperature to be restored to greater than or equal to theminimum established design limits within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The TVA batteries are sized with correction margins to account for factors affecting performance that include temperature and aging andadequate battery design margins.

As a consequence, TVA commits to periodically monitorbattery 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 aseparate environmentally controlled area outside the engineered safety feature switchgear rooms. The temperature of the room containing the batteries is currently monitored at leastevery 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> during operator tours. If battery room temperature were to decrease belowadministrative limits, TVA will implement corrective measures to restore battery roomtemperature in accordance with plant procedures.

Historic data indicate that temperature deviation between cells in a given battery have notdeviated more than 30F between the highest and lowest temperature cell. This meetsIEEE 450-2002 recommendation that the maximum temperature deviation across the batterynot exceed a maximum of 50F.Based on these considerations and the fact that batteries have very large thermal inertia, it ishighly likely that a room temperature excursion would be corrected prior to the batteryelectrolyte reaching its maximum or minimum design temperature.

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

Technical Justification for TS 3.8.6 Action E changeTVA proposes adding new TS 3.8.6 Action G to address the condition in which more than onerequired vital or DG battery has battery parameters not within the limits specified in Conditions Athrough F. If this condition exists, there is not sufficient assurance that the batteries will becapable of performing their intended safety function.

With redundant batteries

involved, loss offunction is possible for multiple systems that depend upon the batteries.

Proposed RequiredAction G.1 requires the affected battery parameters be restored to within limits within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.The 2-hour time period is consistent with similar LCOs established by the TS (i.e., TS 3.8.9Distribution Systems -Operating) and is reasonable considering the potential for loss of functionof components that depend on the batteries (e.g., AC vital bus subsystem(s),

electrical breakercontrol/position indication power). Accordingly, a relatively short duration is provided to resolvethe condition with minimum risk.E1-19 of 29 3.3.10 TS 3.8.6 Action HThe proposed change deletes existing Action B and replaces it with new Action H.Technical Justification for TS 3.8.6 Action B changeExisting Condition B describes three Conditions of battery cell parameter inoperability.

Theseconditions 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; and3. One or more batteries with one or more battery cell parameters not within Category Cvalues.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 forbattery 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 Athrough 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 maximumexpected load requirements.

New Condition H also addresses the case where one requiredvital battery or one required DG battery with one or more battery cells float voltage less than2.07V and a float current greater than 2 amps for the vital batteries or greater than 1 amp for theDG batteries.

Since battery capacity may be incapable of performing the intended designfunction, new Required Action H. 1 requires the associated battery to be immediately declaredinoperable.

3.3.11 SR 3.8.6.1, SR 3.8.6.2, and SR 3.8.6.3The 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 meetTable 3.8.6-1 Category B limits and c) SR 3.8.6.3 to verify average electrolyte temperature ofrepresentative 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 changeThe elimination of existing SR 3.8.6.1 and SR 3.8.6.2 is consistent with the elimination ofTS 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 withrestoring 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 extendedbattery 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 greaterthan or equal to 2.13V is a maintenance limit; and (3) specific gravity measurement criteria arebeing 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 attheir current level, and that actions to restore deficient values will be implemented according toTVA corrective action program.E1-20 of 29 Furthermore, the battery and its preventive maintenance and monitoring program are under theregulatory requirements of 10 CFR 50.65. This relocation will continue to assure that the batteryis maintained at current levels of performance, and that operators appropriately focus onmonitoring 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 BatteryMonitoring 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 sectionsprovide assurance that battery quality and operability will continue to be maintained.

3.3.12 New SR 3.8.6.1 and SR 3.8.6.2The 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 changeTVA proposes adding new SR 3.8.6.1 and SR 3.8.6.2, which require verification every 7 daysthat the float current for each vital battery is less than or equal to 2 amps and that each DGbattery is less than or equal to 1 amp. In addition, a Note states that the limit is not required tobe met when the associated

.battery terminal voltage is less than the minimum established floatvoltage of SR 3.8.4.1 (for the vital batteries) and SR 3.8.4.2 (for the DG batteries).

The purposeof the SRs is to determine the state of charge of the battery.

Float charge is the condition inwhich the battery charger is supplying the continuous small amount of current (i.e., less than orequal 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 chargedstate. The float current requirements are based on the float current indicative of a chargedbattery.

As stated above in Section 3.3.4 above, the use of float current to determine the stateof charge of the battery is consistent with the battery manufacturer recommendations.

The Noteis acceptable since when the float voltage is not maintained, the Required Actions of TS 3.8.4Action A or E are being taken, which provide the appropriate and necessary verifications of thebattery condition.

3.3.13 New SR 3.8.6.3The proposed change adds new SR 3.8.6.3.Technical Justification for New SR 3.8.6.3 changeTVA proposes adding new SR 3.8.6.3, which requires verification every 31 days that the floatvoltage of pilot cells for the vital and DG batteries is greater than or equal to 2.07V. This voltagelevel represents the minimum acceptable voltage for operability.

The Battery Monitoring andMaintenance Program in new TS Section 5.7.2.21 includes actions to restore battery cells withfloat voltage less than 2.13V and actions to verify that the remaining cells are greater than orequal to 2.07V when a cell or cells have been found to be less than 2.13V. The 31 dayfrequency provides reasonable assurance that the battery can perform its intended safetyE1-21 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 3.8.6.4The proposed change adds new SR 3.8.6.4.Technical Justification for New SR 3.8.6.4 changeTVA proposes adding new SR 3.8.6.4, which requires verification every 31 days that theelectrolyte level of each individual cell in the vital and DG battery is greater than or equal to theminimum established design limits. Operation of the batteries at electrolyte levels greater thanthe minimum established design limit ensures that the battery plates do not suffer physicaldamage and continue to maintain adequate electron transfer capability.

TVA also proposes relocating the specific limiting values for the battery electrolyte level that arein 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 greaterthan 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 directlyrelated to the battery's ability to perform its required safety function.

Incorporating the minimumestablished design level limit into the plant's UFSAR provides reasonable assurance that thevalue will be appropriately maintained to accurately reflect the design of the plant.3.3.15 New SR 3.8.6.5The proposed change adds new SR 3.8.6.5.Technical Justification for New SR 3.8.6.5 changeTVA proposes adding new SR 3.8.6.5, which requires verification every 31 days that thetemperature of each vital and DG battery pilot cell is greater than or equal to the minimumestablished design limits. This SR replaces existing SR 3.8.6.3, which requires verifying theaverage (versus pilot cell) electrolyte temperature every 92 days. Batteries have very largethermal 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 batteryroom temperatures.

As a result, the pilot cell temperature is a valid representation of thetemperature 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 theelectrolyte temperature to be greater than or equal to the "minimum established design limits."Depending on the available excess capacity of the associated

battery, the minimumtemperature necessary to support operability of the battery can vary. Relocation to the BatteryMonitoring and Maintenance Program will allow flexibility to monitor and control this limit atvalues directly related to the battery ability to perform its intended function.

Incorporating theminimum 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 theplant.E1-22 of 29 3.3.16 New SR 3.8.6.6The proposed change adds new SR 3.8.6.6.Technical Justification for New SR 3.8.6.6 changeTVA proposes adding new SR 3.8.6.6, which requires verification every 92 days that the floatvoltage of all connected cells for the vital and DG batteries is greater than or equal to 2.07 V percell (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 floatvoltage 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.

Floatvoltages in this range or less, but greater than 2.07 Vpc, are addressed in the BatteryMonitoring and Maintenance Program.

Furthermore, the Battery Monitoring and Maintenance Program includes actions to restore battery cells with float voltage less than 2.13 Vpc andactions to verify that the remaining cells are greater than or equal to 2.07 Vpc when a cell orcells have been found to be less than 2.13 Vpc. The 2.07 Vpc limit reflects the Operability limitfor the batteries.

With all battery cells above 2.07 Vpc, there is adequate assurance that theterminal voltage is at an acceptable threshold for establishing battery operability.

3.3.17 New SR 3.8.6.7The proposed change moves the battery capacity test from existing SR 3.8.4.14 to newSR 3.8.6.7.Technical Justification for New SR 3.8.6.7 changeSee Section 3.1.9 above for the technical justification.

3.4 TS 5.7.2.21, Battery Monitoring and Maintenance ProgramThe proposed change would add a new Battery Monitoring and Maintenance Programrequirements as TS 5.7.2.21.

Technical Justification for new TS 5.7.2.21TVA proposes new TS 5.7.2.21, "Battery Monitoring and Maintenance Program,"

to read asfollows.Battery Monitoring and Maintenance ProgramThis program provides controls for battery restoration and maintenance.

The program shall be inaccordance with the IEEE Std. 450-2002, "IEEE Recommended Practice for Maintenance,

Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications,"

asendorsed by RG 1.129, Revision 2 (RG), with RG exceptions and program provisions asidentified 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 thisprogram.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 bebased on the lowest voltage cell in the battery."

4. In RG 1.129, Regulatory Position 3, Subsection 5.4.1, "State of Charge Indicator,"

thefollowing statements in paragraph (d) may be omitted:

'When it has been recorded thatthe charging current has stabilized at the charging voltage for three consecutive hourlymeasurements, the battery is near full charge. These measurements shall be madeafter the initially high charging current decreases sharply and the battery voltage rises toapproach 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 > 2.13Vwhen 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 levelbelow the top of the plates;4. Limits on average electrolyte temperature, battery connection resistance, and batteryterminal voltage; and5. 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, celltemperature, float voltage, connection resistance, and physical condition) will be relocated tothis program.

The Battery Maintenance and Monitoring Program will ensure that the abovebattery parameters will be maintained and that actions will be implemented should the batteryparameter(s) not be met.The TS 5.7.2.21 Battery Monitoring and Maintenance Program provides assurance that thebattery parameters will be monitored and controlled in accordance with the program, and thatactions 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 ModelSafety Evaluation provided for TSTF-500 as the basis for this change, TVA reviewedE1-24 of 29 Section 2.2 of the model application and has included all applicable information requested bythe NRC in this section.

Furthermore, Section 2.2 of the model application included otherverifications and requested changes to the UFSAR. TVA is providing commitments to ensurethe requested verifications and UFSAR changes are made prior to implementing the changesrequested in this License Amendment Request (LAR). The list of commitments is provided inEnclosure 2 to this LAR.The TVA process governing the processing and submittal of TSs changes and LicenseAmendment Requests requires that the appropriate organizations (e.g., Operations,

Training, Engineering, Maintenance, Chemistry, Radiation Protection, and Work Control) identify thedocuments that are affected by each proposed change to the TSs and Operating Licenses.

Among the items that are considered are training, plant modifications, procedures, specialimplementation constraints, design documents, surveillance instructions associated withTSs SRs, Technical Requirements Manual, TSs Bases, and UFSAR. The process requires thatprocedures and design document changes necessary to support TSs Operability are approvedprior to implementation of the license amendment.

The process also provides assurance thatthe 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 powersystems at WBN which are designed to comply with the following applicable regulations andrequirements:

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 PlantProtection Systems";

RG 1.63, Revision 2, "Electric Penetration Assemblies in Containment Structures forWater-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 NuclearPower 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 forNuclear Power Plants";RG 1.129, Revision 1, "Maintenance,

Testing, and Replacement of Large Lead StorageBatteries for Nuclear Power Plants";RG 1.153, Revision 0, "Criteria for Power, Instrumentation, and Control Portions of SafetySystems";

RG 1.155, Revision 1, "Station Blackout";

andRG 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 theapplicable regulations and requirements.

4.2 Precedent

An acceptance review in accordance with LIC-1 09 was issued for the following plants: ArkansasNuclear One, Units 1 and 2, and Palo Verde, Units 1, 2 and 3. Both sites submitted TS changesbased on the model application contained in TSTF-500.

The proposed TS changes for thoseplants were based on the DC electrical power distribution model referenced in the Bases forNUREG-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 1DC electrical power distribution system is significantly different from that referenced in themodel application, TVA is submitting a stand-alone LAR that provides the technical andregulatory 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 "BatteryMonitoring 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 cellsas 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 notinvolve a significant hazards consideration.

TVA's conclusion is based on its evaluation inaccordance 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 orconsequences of any accident previously evaluated?

Response:

No.The proposed changes restructure the Technical Specifications (TS) for the directcurrent (DC) electrical power system and are consistent with Technical Specifications Task Force (TSTF) change TSTF-360, Revision 1 and TSTF-500, Revision

2. Theproposed changes modify TS Actions relating to battery and battery chargerinoperability.

The DC electrical power system, including associated battery chargers, isnot an initiator of any accident sequence analyzed in the Updated Final Safety AnalysisReport (UFSAR).

Rather, the DC electrical power system supports equipment used tomitigate accidents.

The proposed changes to restructure TS and change surveillances for batteries and chargers to incorporate the updates included in TSTF-360, Revision 1as updated by TSTF-500, Revision 2, will maintain the same level of equipment performance required for mitigating accidents assumed in the UFSAR. Operation inaccordance with the proposed TS would ensure that the DC electrical power system iscapable of performing its specified safety function as described in the UFSAR.Therefore, the mitigating functions supported by the DC electrical power system willcontinue to provide the protection assumed by the analysis.

The relocation of preventive maintenance surveillances, and certain operating limits and actions, to a licenseecontrolled Battery Monitoring and Maintenance Program will not challenge the ability ofthe DC electrical power system to perform its design function.

Appropriate monitoring and maintenance that are consistent with industry standards will continue to beperformed.

In addition, the DC electrical power system is within the scope of10 CFR 50.65, "Requirements for monitoring the effectiveness of maintenance atnuclear 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 asdescribed in the UFSAR will not be affected by the proposed changes.

Therefore, theconsequences of previously analyzed accidents will not increase by implementing thesechanges.Therefore, the proposed amendment does not involve a significant increase in theprobability or consequences of an accident previously evaluated.

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

Response:

NoThe 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 powersystem supports equipment used to mitigate accidents.

The proposed changes torestructure 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, willmaintain the same level of equipment performance required for mitigating accidents assumed in the UFSAR. Administrative and mechanical controls are in place to ensureE1-27of29

.

the design and operation of the DC systems continues to meet the plant design basisdescribed 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 ofsafety?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 bemaintained in accordance with the plant-specific design bases as a result of theproposed changes.

The proposed changes will not adversely affect operation of plantequipment.

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 powerto safety-related loads in accordance with analysis assumptions.

TS changes made tobe 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 andthe current TSs.Therefore, the proposed changes do not involve a significant reduction in a margin ofsafety.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 proposedmanner, (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 securityor to the health and safety of the public.5.0 ENVIRONMENTAL CONSIDERATION A review has determined that the proposed amendment would change a requirement withrespect to installation or use of a facility component located within the restricted area, as definedin 10 CFR Part 20, and would change an inspection or surveillance requirement.

However, theproposed 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 releasedoffsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion setforth in 10 CFR 51.22(c)(9).

Therefore, pursuant to 10 CFR 51.22(b),

no environmental impactstatement or environmental assessment need be prepared in connection with the proposedamendment.

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, andReplacement of Vented Lead-Acid Batteries for Stationary Applications,"

The Institute ofElectrical 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 IProposed WBN Unit I TS Changes (Markups)

Al-1 DC Sources -Operating 3.8.43.8 ELECTRICAL POWER SYSTEMS3.8.4 DC Sources -Operating LCO 3.8.4Four channels of vital DC and four Diesel Generator (DG) DC electrical powersubsystems 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 forrequired Vital chargers.
3. Spare DG Chargers 1A1, 1B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
24. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystem.

APPLICABILITY:

MODES 1, 2, 3, and 4.ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Restore vital battery terminal 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />scharger inoperable, voltage to greater than orequal to the minimumestablished float voltage.ANDA.2 Verify vital battery float Once per 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />scurrent < 2 amps.ANDA.3 Restore vital battery charger 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />sto OPERABLE status.B. One required vital battery B.1 Restore vital battery to 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sinoperable.

OPERABLE status.AC. One required vital DC AC.1 Restore vital DC eleetFieal-2 hours powerF sbsystemchannel tosub6ysteinchannel OPERABLE status.inoperable for reasonsother than Condition A or B.BD. Required Action and BD.1 Be in MODE 3. 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />sassociated Completion ANDTime of Condition A, B or Cnot met. 9D.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />(continued)

Watts Bar-Unit 13.8-24 DC Sources -Operating 3.8.4ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIMEE. One required DG battery E.1 Restore DG battery terminal 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />scharger inoperable, voltage to greater than or equalto the minimum established float voltage.ANDE.2 Verify DG battery float current Once per 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s< 1 amp.ANDE.3 Restore DG battery charger to 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />sOPERABLE status.F. One required DG battery F.1 Restore DG battery to 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sinoperable.

OPERABLE status.GG. One required DG DC GG.1 Restore DG DC electrical 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />selectrical power subsystem power subsystem toinoperable 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, orG not met.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify vital battery terminal voltage is greater than or 7 daysequal to the minimum established-'

128 V (132 V forvital batteiy-V-Gn float ehargevoltage.

SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 daysequal to the minimum established

--1-24-V-enfloat

-GhaFevoltage.

SR 3.8.4.3 Verify for the vital batteries that the alternate feeder 7 daysbreakers to each required battery charger are open.SR 3.8.4.4 Verify correct breaker alignment and indicated power 7 daysavailability for each DG 125V DC distribution paneland associated battery charger.(continued)

Watts Bar-Unit 13.8-25 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS (continued)

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

QRVerify for the vital batteries is_ 80 E 6 ohm for inter col connectiGons,

< 50 E 6 ohmfor inter rack connetons, 120 E 6 ohm-fo;r intrtierfrntr rconnect

,and -50 E 68 oh for teminfalGGAReGtGR Verify no Visibble corroion69-at ter~minals and coennectors-92-daySfor the; DG batteries.

ORVerify connection resistanco for the DG batteries ist 80 E 6 ohm for inter Goil cnnection, f 50=E 6 ohm3,fnor inter tier cnnections, and 50 Em 6 ohm forterminal connections.

SR 3.9.4.7-Verify batte~' cells, coil' plates, and racks Show no 1: mvisual idctOn f physical damage or abnormalSR~&4Remoeve vfisfible termninal corrosion and verify batter; 1-2 menthscGell to cell and teirminOa.l cnecin are cAPted wiethantR~iw cor.Arosion m~aterial.

(continued Watts Bar-Unit 13.8-26 DC Sources -Operating 3.8.4SURVEILLANCE FREQUENCY Verif.. connection rosistAnco for the vital batteries is 12 menths4 80 E-6 ohmfrA Wno ce911 connotions

-50 E 6R forFinter rack connections, 120 E 6R ohm forintr tier-connections, aRnd 50 E 6 ohm for termin.al G0RR9GtGA

&R 2_84WQ Vorify connec-tioresitac for the DG batteries 6 1-2 menthi<- 8_0 6 hRm- fo-r iRter cellII connections,

-50 E 6 ohmfmor inter tier co Gnnecti8nS, and _' -50 EF -6 ohm forterminal connections.

SR 3.8.4.14-5 NOTEThio Sur-, eillnce is normally not peF....,d inMODE 1, 2, 3, o-r 4. HoWeer, cedit mRay be takenfor unplanned events that satisfy this SR.Verify each vital battery charger is Gapable ef 18 monthsrecharging its associated batter';

from a srioocapacity discharge test while supplying normallead6supplies

> 200 amps at greater than or equal tothe minimum established float voltage for > 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.ORVerify each vital battery charger 0s-eapable-of operating for >_ 4 ho-urs- at courrent limnit 2:20 :250aa4Wan recharge the battery to the fully chargedstate within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> while supplying the largestcombined demands of the various continuous steadystate loads, after a battery discharge to the boundingdesign basis event discharge state.(continued)

Watts Bar-Unit 13.8-27Amendment 54 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.426 NOTECredit may be taken for Uplannod

-vents that satisfythis SR.Verify each diesel-geRe.,ateDG battery charger 18 monthssupplies

> 20 amps at greater than or equal to theminimum established float voltage for > 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />sis-cGipable Of FeGaiig!RiyI its GGOiat JJLtte tFE)ri ase -c orcpacity dischargo test While supplying eFFnal .ORVerify each DG battery charger can recharge thebattery to the fully charged state within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> whilesupplying the largest combined demands of thevarious continuous steady state loads, after a batterydischarge to the bounding design basis eventdischarge state.SR 3.8.4.47

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

1. The modified performance discharge test inSR 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 betaken for unplanned events that satisfy this SR.Verify battery capacity is adequate to supply, and 18 monthsmaintain in OPERABLE status, the requiredemergency loads and any connected nonsafety loadsfor the design duty cycle when subjected to a batteryservice test.Watts Bar-Unit 13.8-28Amendment 12 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.4.!4 NOTEST-hi6 Survoillance8 i ot po~formFed in MODE 1, 2, 3,or 4 for required vita' batteries.

Credit may betakon for unplanned eVRnts that satisfy this SR.Vorify batter' capacity is ; 80% of themanufactuor's 6-fnectuhs r-ating when subjoctod to a po4ormaRce discharge torst-or moifed oformanco discharge test- AND12 months whenbatte,-y rhes w6hdogradation Or hasreac hed 85% expected lifo wth-capacity 4100% OfmfanRufacturor's ratingANQ24 meonths;i.

whenbatter; has reached85% of expocted lifowith capacit"

ý 100%of mnanufacturer's Watts Bar-Unit 13.8-29Amendment 12 DC Sources-Shutdown 3.8.53.8 ELECTRICAL POWER SYSTEMS3.8.5 DC Sources -ShutdownLCO 3.8.5Vital DC and Diesel Generator (DG) DC electrical power subsystems shall beOPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems -Shutdown" and to support theDiesel 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.Spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted for requiredvital chargers.
3. Spare DG chargers 1Al, 1 B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
24. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystems.

APPLICABILITY:

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

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

subsystems inoperable.

ORA.2.1 Suspend CORE Immediately ALTERATIONS.

ANDA.2.2 Suspend movement of Immediately irradiated fuel assemblies.

(continued)

Watts Bar-Unit I3.8-30 DC Sources-Shutdown 3.8.5ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. (continued)

ANDA.2.3 Initiate action to suspend Immediately operations involving positivereactivity additions.

ANDA.2.4 Initiate action to restore Immediately required vital DC electrical power subsystems toOPERABLE status.B. One or more required DG B.1 Declare associated DG Immediately DC electrical power inoperable subsystems inoperable.

Watts Bar-Unit 13.8-31 DC Sources-Shutdown 3.8.5SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.5.1-----------------

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

The following SRs are not required to beperformed:

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, thefollowing SRs are applicable:

In accordance withapplicable SRsSR 3.8.4.1SR 3.8.4.2SR 3.8.4.3SR 3.8.4.4SR 3.8.4.5SR 3.8.4.6SR 3.8.4.7SR 3.8.4.9SR 3.9.4!.!S R 3.9..1SR 384.14Watts Bar-Unit 13.8-32 Battery GeU-Parameters 3.8.63.8 ELECTRICAL POWER SYSTEMS3.8.6 Battery Gell-Parameters ILCO 3.8.6Battery Gell-parameters for required 125 V vital batteries and 125 V dieselgenerator (DG) batteries shall be within the limits of Table 3.6.4 1.When associated DC electrical power subsystems and DGs are required to beOPERABLE.

APPLICABILITY:

ACTIONS----------------------------

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

CONDITION REQUIRED ACTION COMPLETION TIMEA. Onie or moroe bhattorioc with A. I Vorify pilot c8l16 oloctrolyto 8eone Or moroe batter,'

coil level -and- float voltage mooetparametere not Within Table 3.8.69 1Catogor,'

CCatogor,'

A or B lim~itS.At4PA.2 Verify battery cel!

24-he-wmnoot Table 3-8.65 1 Categor C(nnANDtheeaftef ANDA.3 Rectoro batter,'

cell 3-1 daysparameterc to Category Aand liits oaf Table 3861(continued)

Watts Bar-Unit 13.8-33 Battery GeII-Parameters 3.8.6ACTIONS (continued)

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

Timo of Condition A notOno or mrenr- bhatteries withaVorage oloctrolye temper1ture of therepresentative cells 4-0 'F-for vital batterIes and -502Pfor DG ba4tteres OnA or more batteries; withone or mo-re battwGerol!

parametes net WithiCategory 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 7udaedCategory A lmts(continued)

Wafts Bar-Unit 13.8-34 Battery Ge4-Parameters 3.8.6Insert 1 -TS 3.8.6 ActionsACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Perform SR 3.8.4.1.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith one or more batterycells float voltage < 2.07 V. ANDA.2 Perform SR 3.8.6.1.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sANDA.3 Restore affected cell float 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />svoltage > 2.07 V.B. One required vital battery B.1 Perform SR 3.8.4.1.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith float current > 2 amps.ANDB.2 Restore vital battery float 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />scurrent to < 2 amps.C. One required DG battery C.1 Perform SR 3.8.4.2.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith one or more batterycells float voltage < 2.07 V. AND 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sC.2 Perform SR 3.8.6.2.

24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />sANDC.3 Restore affected cell floatvoltaqe > 2.07 V.DD.One required DG batterywith float current > 1 amp.D._1 Perform SR 3.8.4.2.2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s12 hoursANDD.2 Restore DG battery floatcurrent to -< 1 amp.E. One required battery -------------------

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

with one or more cells with Required Actions E.1 and E.2 are onlyelectrolyte level less than applicable if electrolyte level was belowminimum established the top of plates.design limits.E.1 Restore electrolyte level to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />sabove top of plates.ANDWatts Bar-Unit 1Inserts for Page 3.8-34 Battery GeN-Parameters 3.8.6CONDITION REQUIRED ACTION COMPLETION TIMEE.2 Verify no evidence of leakage.

12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />sANDE.3 Restore electrolyte level to 31 daysgreater than or equal tominimum established designlimits.F. One required battery F.1 Restore battery pilot cell 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />swith Pilot cell electrolyte temperature to greater than ortemperature 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 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sbatteries with battery within limits.parameters not within limits.ORMore than one reguired DGbatteries with batteryparameters 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.OROne required vital batterywith one or more batterycells float voltage < 2.07 Vand float current > 2 amps.OROne required DG batterywith one or more batterycells float voltage < 2.07Vand float current>

1 amp. IIWatts Bar-Unit 1Inserts for Page 3.8-34 Battery Gell-Parameters 3.8.6SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.6.2 Verify batteyr.

col pa.am.oto..

moo.t Table 3.8.6 1Category B limis 92 daysAND'GGe w:thin 21 hour2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />safe-a bttefyL

-110 I forvital battories (11 3.5V for vital battery V)or 106.5 V for 1DGratte4ues ANDOnce mithin :24 hoursovercharge

~150 Vfopr i~tal battorebattery V) or 115 VSR 3.8.6.3 Verify average eloctroTte temperature of 92 daysrepresentative cells is 60 OF for vital batteries and50°F for the PG battries.j

[Replace Surveillance Requirements with Insert 2 (TS 3.8.6 SRs).1Watts Bar-Unit 13.8-35 Battery GeU-Parameters 3.8.6Insert 2 -TS 3.8.6 SRsSURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 ------------------------

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

Not required to be met when vital battery terminalvoltage is less than the minimum established floatvolta-ge of SR 3.8.4.1.Verify each vital battery float current is < 2 amps. 7 daysSR 3.8.6.2 ------------------------

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

Not required to be met when DG battery terminalvoltage is less than the minimum established floatvoltage of SR 3.8.4.2.Verify each DG battery float current is < 1 amp. 7 daysSR 3.8.6.3 Verify each required vital and DG battery pilot cell 31 daysfloat voltage is > 2.07 V.SR 3.8.6.4 Verify each required vital and DG battery connected 31 dayscell electrolyte level is greater than or equal tominimum established design limits.SR 3.8.6.5 Verify each required vital and DG battery pilot cell 31 daystemperature is greater than or equal to minimumestablished design limits.SR 3.8.6.6 Verify each required vital and DG battery connected 92 dayscell float voltage is -> 2.07 V.Watts Bar-Unit IInserts for Page 3.8-35 Battery Gell-Parameters 3.8.6SURVEILLANCE FREQUENCY SR 3.8.6.7 -------------------------

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

Credit may be taken for unplanned events thatsatisfy this SR.Verify battery capacity is > 80% of the manufacturer's 60 monthsrating when subiected to a performance discharge test or a modified performance discharge test. AND12 months whenbattery showsdegradation, or hasreached 85% of theexpected life withcapacity

< 100% ofmanufacturer's ratingAND24 months whenbattery has reached85% of the expectedlife with capacity

>100% ofmanufacturer's ratingWatts Bar-Unit 1Inserts for Page 3.8-35 Battery 3.8.6Table 3.8.6 1 (page 1 of !)

C'II PDammetr irimentsCAT-EORY A_: CATEGORY B: CATEGORPARAME LIMITS FOR EACH LIMITS FOR EACH ALLOWABLE LMITDESIGNATED PILOT CELL 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 level4indicatioR nmark (a) indication mark (a)Fleat Veltage _2-.- .2..V .>2.074Specific Gravity (b)(c) -1.200 1.1-95 hnet mror than 0.0:20beloW average of allAND connected coiAve~age of al ANDconnected cellsAverage of agWconnected cells(a) It it aceptable f4or the 9electrole level to tempo*rarly increase above the specified maxI mIm levelduring equalizing charges provided it is not evwflowing.

(b) Corrected far electrolyte temperature and level. Level correction is not required,

however, whenbatter; charging 6 e- 2 amps when on float charge for Vital batteries, and- -4 1..0 amp for DGbatteres.

(G) A batter: chargingI current of e- 2 amps when on float charae for vital batteries6

-and -41.0 amoR for& IDG batterfies is acceptable for mneeting specific gravity limits. followineg a batter,'

recharge, for amaximum 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 Drier to expiratien of the 31 davaiiewa4efRf r .... .r ...............

....Watts Bar-Unit I3.8-36 Procedures, Programs and Manuals5.75.7 Procedures,

Programs, and Manuals5.7.2.21 Battery Monitoring and Maintenance Pro-gramThis Pro-gram provides controls for battery restoration and maintenance.

The programshall be in accordance with IEEE Standard (Std) 450-2002, "IEEE Recommended Practice for Maintenance,

Testing, and Replacement of Vented Lead-Acid Batteries forStationary Applications,"

as endorsed by Regulatory Guide 1.129, Revision 2 (RG), withRG 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 afterconducting discharge tests.2. RG 1.129, Regulatory Position 1, Subsection 2, "References,"

is notapplicable 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 thebattery."

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 currenthas stabilized at the charging voltage for three consecutive hourlymeasurements, the battery is near full charge. These measurements shall be made after the initially high charging current decreases sharplyand 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 ofeach 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 batterycells is -2.13V when the float voltage of a battery cell has been found tobe < 2.13V:3. Actions to equalize and test battery cells that had been discovered withelectrolyte level below the top of the plates:4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and5. A requirement to obtain specific gravity readings of all cells at eachdischar-ge test, consistent with manufacturer recommendations.

Watts Bar-Unit 15.0-25b ATTACHMENT 2Proposed WBN Unit I Bases Page Changes (Markup)(For Information Only)A2-1 DC Sources-Operating B 3.8.4B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.4 DC Sources -Operating BASESBACKGROUND The station DC electrical power system provides the AC emergency powersystem with control power. It also provides both motive and control power toselected safety related equipment and preferred AC vital bus power (viainverters).

As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1),

the DCelectrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a singlefailure.

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 safetyfunction is to provide control power for engineered safety features equipment, emergency

lighting, vital inverters, and other safety-related DC poweredequipment for the entire unit. The system capacity is sufficient to supply theseloads and any connected nonsafety loads during normal operation and to permitsafe 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 asingle 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 areassociated with Train B) and consists of four lead-acid-calcium batteries, eightbattery 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 allother channels so that a single failure in one channel will not cause a failure inanother channel.

Each channel consists of a battery charger which suppliesnormal DC power, a battery for emergency DC power, and a battery board whichfacilitates load grouping and provides circuit protection.

These four channels areused to provide emergency power to the 120V AC vital power system whichfurnishes 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 andalso have manual access to a spare (backup) charger for use upon loss of thenormal charger.(continued)

Watts Bar-Unit 1B 3.8-54Revision 105 DC Sources-Operating B 3.8.4BASESBACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Additionally, battery boards I, II, Ill, and IV have manual access to the fifth vitalbattery system. The fifth 125V DC Vital Battery System is intended to serve as areplacement 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 ofoperation.

Each of the vital DC electrical power subsystems provide the control power for itsassociated Class 1 E AC power load group, 6.9 kV switchgear, and 480V loadcenters.

The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, theypower the emergency DC lighting system.The vital DC power distribution system is described in more detail in Bases forLCO 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 loadcontinuously for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> in the event of a loss of all AC power (stationblackout) without an accident or for 30 minutes with an accident considering asingle failure.

Load shedding of non-required loads will be performed to achievethe required coping duration for station blackout conditions.

Each 125V DC vital battery is separately housed in a ventilated room apart fromits charger and distribution

centers, except for Vital Battery V. Each subsystem is located in an area separated physically and electrically from the othersubsystem to ensure that a single failure in one subsystem does not cause afailure in a redundant subsystem.

There is no sharing between redundant Class1 E subsystems, such as batteries, battery chargers, or distribution panels.The batteries for the vital DC electrical power subsystems are sized to producerequired capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the100% design demand. The voltage limit is 2.13 V per cell, whiGh correspends toa total minimum voltage output of ! 29V por batteFry (1232 for Vital Batter; V). Thecriteria 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 specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital battery) the total minimum outputvoltage is 124V and for a 62 cell battery (5tI vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or discharging.

Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further charginqper manufacturer's instructions.

Optimal long term performance

however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadeguate over-potential, which limits the formation of lead sulfate and selfdischarge.

(continued)

Watts Bar-Unit 1B 3.8-55 DC Sources-Operating B 3.8.4BASESBACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Each Vital DC electrical power subsystem has ample power output capacity forthe steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.

Each batterycharger also has sufficient capacity to restore the battery bank from the designminimum charge to its fully charged state within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (with accident loadsbeing supplied) following a 30 minute AC power outage and in approximately 36hours (while supplying normal steady state loads following a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> AC poweroutage),

(Ref.6).The battery charger is normally in the float-charge mode. Float-charge is thecondition in which the charger is supplying the connected loads and the batterycells are receiving adequate current to optimally charge the battery.

This assuresthe internal losses of a battery are overcome and the battery is maintained in afully charged state.When desired, the charger can be placed in the equalize mode. The equalizemode is at a higher voltage than the float mode and charging current iscorrespondingly higher. The battery charger is operated in the equalize modeafter a battery discharge or for routine maintenance.

Following a batterydischarge, the battery recharge characteristic accepts current at the current limitof the battery charger (if the discharge was significant, e.g., following a batteryservice test) until the battery terminal voltage approaches the charger voltagesetpoint.

Charging current then reduces exponentially during the remainder ofthe rechar-ge cycle. Lead calcium batteries have recharge efficiencies of greaterthan 91%, so once at least 110% of the ampere-hours discharged have beenreturned, the battery capacity would be restored to the same condition as it wasprior to the discharge.

This can be monitored by direct observation of theexponentially 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 andfield-flash circuits have power supplied from their respective 125V distribution panel. The normal supply of DC current is from the associated charger.

Thebattery provides control and field-flash power when the charger is unavailable.

The charger supplies the normal DC loads, maintains the battery in a fullycharged condition, and recharges (480V AC available) the battery whilesupplying the required loads regardless of the status of the unit. The batteries are physically and electrically independent.

The battery has sufficient capacitywhen fully charged to supply required loads for a minimum of 30 minutesfollowing a loss of normal power. Each battery is normally required to supplyloads during the time interval between loss of normal feed to its charger and thereceipt of emergency power to the charger from its respective DG.(continued)

Watts Bar-Unit 1B 3.8-56Revis ion 113 DC Sources-Operating B 3.8.4BASESAPPLICABLE SAFETY ANALYSESThe initial conditions of Design Basis Accident (DBA) andtransient 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 DCelectrical power for the emergency auxiliaries, and control and switching duringall power for the emergency auxiliaries, and control and switching during allMODES 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 theplant. This includes maintaining the DC sources OPERABLE during accidentconditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.The DC sources satisfy Criterion 3 of the NRC Policy Statement.

LCOFour 125V vital DC electrical power subsystems, each vital subsystem channelconsisting 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 eachconsisting of a battery, a dual battery charger assembly, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE toensure the availability of the required power to shut down the reactor andmaintain it in a safe condition after an anticipated operational occurrence (AOO)or a postulated DBA. Loss of any DC electrical power subsystem does notprevent the minimum safety function from being performed (Ref. 4).An OPERABLE vital DC electrical power subsystem requires all requiredbatteries and respective chargers to be operating and connected to theassociated DC buses.The LCO is modified by twefour Notes. Note 1 indicates that Vital Battery V maybe substituted for any of the required vital batteries.

However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.

Note2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted forrequired vital charqers.

Note 3 indicate that spare DG chargers 1Al, 1B1, 2A1, or2B1 may be substituted for required DG chargers.

However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.

Note 24 has boon addod toindicates that the C-S DG and itsassociated DC subsystem may be substituted for any of the required DGs.However, the C-S DG and its associated DC subsystem cannot be declaredOPERABLE until it is connected electrically in place of another DG, and it hassatisfied applicable Surveillance Requirements.

(continued)

Watts Bar-Unit 1B 3.8-57Revision 113 DC Sources-Operating B 3.8.4BASESAPPLICABILITY The four vital DC electrical power sources and four DG DC electrical powersources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safeplant operation and to ensure that:a. Acceptable fuel design limits and reactor coolant pressure boundarylimits are not exceeded as a result of AOs or abnormal transients; andb. Adequate core cooling is provided, and containment integrity and othervital functions are maintained in the event of a postulated DBA.The DC electrical power requirements for MODES 5 and 6 are addressed in theBases for LCO 3.8.5, "DC Sources -Shutdown."

ACTIONSA.1. A.2. A.3. E.. E.2. and E.3Condition A. represents oe vital chrespond to an event, and a poteRti*a4nnol with a loss of ability to omepletely loss of ability to emi en .ergzd duringnormai operation.

it Is, tleretoe, imperative tnat peraltorsI1 at ostabilizing the plant, minimizing the potential for complete loss of .DC power to theaffecoted-trainR. The 2 hulismit is consistent With the alloweAAd_

timoP for aninoperable 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; chargorand associated ioRporablo bailer,'),

the remaining vital DG electrical poeresubsystem has the capacity to suppedt a. cafe s11-hutdown and to m~itigate anaccident conddition.

SinoR~ a subsequent worst case single failue of theOPE=RABLEm subsystem would, however, result in a sitution wfheerethe ability ofthe 125V DG electrical power subsystem to suppedt its required ESF function isnot assurFed, continRued power operation should not excoe d -2 hourws. T-he 2hourCompletion Time is based on Regulator,'

Guide 1 .93 (Ref. 8) and reflects

_areasonable time to assess plant status as a; func-tion of the inoperable vital PCelectirical power subsystem and, if the vital DC electrical power subsystemA is notrestore9d to- OPERABLE.

status, to prepare to effect an orderly and safe plantsh, 4tawn~(continued)

Watts Bar-Unit IB 3.8-58 DC Sources-Operating B 3.8.4BASESA B.!-and-

.2if the inoperablo8 Vital DC oloctrical power 6ubeystom cannoRQt be rosto4hroRd_

to-OPERABLE status within the required Complotion Time, the plant Must hebFrught to a MODE, iR Which the LCO not apply. To achieve this status, the-plant mAust be brog~lht to at least MODE 2 withnA 6 hourFS and to MODE 5 within368 hours. TPhe allowMAed Completion Times are reasonable, based an operatingf experience, to reach the required plant conditions frmF full power conditions ina4r lorderly mnanner and without challenging plant systems.

The Completion Timne tobring the plant to MODE 5 is6 Gconstent with the tiMe Feqw÷,ed in Regulator; Guide (Ref. 8).G_4Condition G represents one DG with a lss oef ability to chmpletely rosperad to aeveNt. Srinde a subrequet rsingle failue On the o ppoesite train coetd result in aatationa where the requ ired E cS function is not assured, eontirued poweropefation should wi t eXieed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> .The 2 hous t ime WAelim f rinthe isnsenwith the allowed time foPR an inoperable vital DG electrical power subsystemr.

94If the DG Dr electrical power subsystem cannot be restored to OPERAbBLE sotatus in the associated Completier Time, the atssoeated Dh may beinapable of pemin mim g its intended functivo and muvistd be iAmeduately declared inorlThis declaratiero awls requires entry inte applicable conditions and RequiredActions 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).

TheACTIONS provide a tiered response that focuses on returning the battery to thefully charged state and restoring a fully qualified charger to OPERABLE status ina reasonable time period. Required Actions A.1 and E.1 require that the batteryterminal voltage be restored to greater than or egual to the minimum established float voltagqe within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. 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 theminimum established float voltage provides good assurance that, within 12hours, 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 currentportion (the second part) of its recharge cycle. The time to return a battery to itsfully charged state under this condition is simply a function of the amount of theprevious discharge and the recharge characteristic of the battery.

Thus there isgood assurance of fully recharging the battery within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, avoiding apremature 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 1B 3.8-59 DC Sources-Operating B 3.8.4BASESminimum established float voltage within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and the charger is notoperating in the current-limiting mode, a faulty charger is indicated.

A faultycharger that is incapable of maintaining established battery terminal float voltaaqedoes not provide assurance that it can revert to and operate properly in thecurrent limit mode that is necessary during the recovery period following a batterydischarge event that the DC system is designed for.If the charger is operating in the current limit mode after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> that is anindication that the battery is partially discharged and its capacity margins will bereduced.

The time to return the battery to its fully charged condition in this case isa function of the battery charger capacity, the amount of loads on the associated DC system, the amount of the previous discharge, and the rechargecharacteristic of the battery.

The charne time can be extensive, and there is notadequate assurance that it can be recharged within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.Required Actions A.2 and E.2 require that the battery float current be verified lessthan or equal to 2 amps for the vital battery and less than or equal to 1 amp forthe DG battery.

This indicates that, if the battery had been discharged as theresult of the inoperable battery charger, it is now fully capable of supplying themaximum expected load reduirement.

The 2 amp value for the vital battery andthe 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 theinitial 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period the battery float current is not less than or equal to 2 ampsfor the vital battery or 1 amp for the DG battery, then this indicates there may beadditional battery problems and the battery must be declared inoperable.

Required Actions A.3 and E.3 limit the restoration time for the inoperable batterycharger to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This action is applicable if an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established floatvoltage has been used (e.g., balance of plant non-Class 1 E battery charger).

The72 hour Completion Time reflects a reasonable time to effect restoration of thequalified battery charger to OPERABLE status.B.1 and F.1Conditions B and F represent one channel (subsystem) with one batteryinoperable.

With one battery inoperable, the DC bus is being supplied by theOPERABLE battery charger.

Any event that results in a loss of the AC bussupporting 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 behampered 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 dieselgenerator output circuit breakers, etc.) will likely rely upon the battery.

In additionany DC load transients that are beyond the capability of the battery charger andnormally require the assistance of the battery will not be able to be broughtonline. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 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.) areidentified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specificCompletion Times.Watts Bar-Unit 1B 3.8-59a DC Sources-Operating B 3.8.4BASESC.1 and G.1Conditions C and G represent a loss of one DC electrical power subsystem tocompletely respond to an event, and a potential loss of ability to remainenergized during normal operation.

It is therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete lossof DC power to the affected subsystem.

The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit is consistent with theallowed time for an inoperable DC distribution subsystem.

If one of the required DC electrical power subsystems is inoperable for reasonsother than Conditions A or B for the vital batteries or Conditions E or F for the DGDC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accidentcondition.

Since a subsequent worst case single failure could, however, result inthe loss of the minimum necessary DC electrical subsystems to mitigate a worstcase accident, continued power operation should not exceed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The 2 hourCompletion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects areasonable time to assess unit status as a function of the inoperable DCelectrical power subsystem and, if the DC electrical power subsystem is notrestored to OPERABLE status, to prepare to effect an orderly and safe unitshutdown.

D.1 and D.2If the inoperable Vital DC electrical power subsystem cannot be restored toOPERABLE status within the required Completion Time, the plant must bebrought to a MODE in which the LCO does not apply. To achieve this status, theplant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in anorderly manner and without challenging plant systems.

The Completion Time tobring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).9H.1If the DG DC electrical power subsystem cannot be restored to OPERABLEstatus 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 RequiredActions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."

Watts Bar-Unit 1B 3.8-59b DC Sources-Operating B 3.8.4BASESSURVEILLANCE REQUIREMENTS SR 3.8.4.1 and SR 3.8.4.2Verifying battery terminal voltage while on float charge for the batteries helps toensure 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 isthe condition in which the charger is supplying the continuous charge required toovercome 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 steadystate loads of the associated DC subsystem.

On float charge, battery cells willreceive adequate current to optimally charge the battery.

The voltagerequirements are based on the nominal design voltage of the battery and areconsistent with the minimum float voltage established by the batterymanufacturer.

For example the minimum nominal terminal voltage for the 5thVital Battery is 136V (62 cells times 2.20 Vpc), the minimum nominal terminalvoltage for the vital batteries is 132V (60 cells times 2.20 Vpc) and the minimumnominal 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 supportsmaintaining the grid life.The voltage requirements listed above are based on the critical design voltage ofthe battery and are consistent with the initial voltages assumed in the batterysizing calculations.

The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).SR 3.8.4.3Verifying that for the vital batteries that the alternate feeder breakers to eachrequired battery charger is open ensures that independence between the powertrains is maintained.

The 7-day Frequency is based on engineering

judgment, is consistent with procedural controls governing breaker operation, and ensurescorrect breaker position.

SR 3.8.4.4This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning

properly, with all required circuit breakers closed andbuses energized from normal power. The 7 day Frequency takes into accountthe redundant DG capability and other indications available in the control roomthat will alert the operator to system malfunctions.

SR 3.8.4.5 and SR 3.8.4.6Visual inspoc.tio.

U9 toe dotct corro.ion of the battey coIs and connections, ormoeasUr8Fem t of the rosistance of oach ineclitrak nooanda tor-minal connucu:n, pr1y.laec aRn indcic=tn Of pnyscI= damage OFr aonormna Eoe!rioraiu-on that could potentially dograd, battery pe.foermance.

These SRs verify the designcapacity of the vital and DG battery chargers.

According to Regulatory Guide1.32 (Ref. 6). the battery charger supply is recommended to be based on thelargest combined demands of the various steady state loads and the chargingcapacity to restore the battery from the design minimum charge state to therecharged state, irrespective of the status of the unit during these demandoccurrences.

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 1B 3.8-60 DC Sources-Operating B 3.8.4BASESSURVEILLANCE REQUIREMENTS SR 3.8.4.5 and SR 3.8.4.6 (continued)

The limits, established for thiS SR must be no more8 than 20% abovo theresistanco as mneasured during installation, or not above the cefiling valueestablished by the manufacturer.

The SRs provide two options.

One optionrequires that each vital battery charger be capable of supplying 200 amps (20amps for the DG battery charger) at the minimum established float voltage for 4hours. Recharging the battery or testing for a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is sufficient toverify the output capability of the charger can be sustained, that current limitadjustments are Properly set and that protective devices will not inhibitperformance 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. ThisFrequency is conrsidred acceptable based n opaerating expefienre related todetecting corrosion trends.rhe other option requires that each battery changer be caroable of recharging thebattery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the statusof the plant during which these demands occur). This level of loading may notnormally be available following the battery service test and will need to besupplemented with additional loads. The duration for this test may be longer thanthe charger sizing criteria since the battery recharge is affected by float voltage,temperature, and the exponential decay in charging current.

The battery isrecharged 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 toperform the test and the other administrative controls existing to ensure adequatecharger performance during these 18 month intervals.

In addition, thisFrequency is intended to be consistent with expected fuel cycle lengths.(continued)

Watts Bar-Unit 1B 3.8-61Revision 56, 69Amendment 54 DC Sources-Operating B 3.8.4BASESSR 3.8.4.7Visual inspec~tionA of the- batter,'

cells, cel! plates, and batter' rackrs provides, anin;dication of damage or abnormal deterioration that could potentially degrade batter.

The 12 mRonth Frequency for this SR is consistent With IEE 1~=450 (Ref. 9), Whichrecommendr, detailed visual insiqecti9n of coi cnd-ition and racRk intearity on ayea.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 powersystem. The discharge rate and test length should correspond to worst casedesign 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), whichstate 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 modifiedperformance discharge test in lieu of a service test. The modified performance discharge test is a simulated duty cycle consisting of must two rates; the oneminute 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 whichenvelope the duty cycle of the service test. Since the ampere-hours removed bya rated one minute dischar-ge represents a very small portion of the batterycapacity, the test rate can be changed to that for the performance test withoutcompromising the results of the performance discharge test. The batteryterminal voltage for the modified performance dischar-ge test should remainabove the minimum battery terminal voltage specified in the battery service testforthe 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 performthe function specified by this Surveillance, for which adequatedocumentation of the required performance is available; and2.) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in coniunction withmaintenance required to maintain OPERABILITY or reliability.

Watts Bar-Unit 1B 3.8-61 a DC Sources-Operating B 3.8.4BASESSR 3.8.4.8.

SIR. 3.8.41.9-aind SR 3.8.1.10Visual inspection and resistance measuremonts of intrcl, ntrac 8 nede,and- terminall connectfions provide an indication Of physical damage or abnormaldeterioration that could indicate degraded batter; condition.

The anticorrosion mnaterial is used to help ensure good 8eletricial connections and to reducetermin-al deterioration.

The visual inspection for corrosionA is not inended toreqireremval of an~d inspection under eac-i-h termin-al cneto.The remoevalof voisibhle corrosio isa rentive mnaintenance SR. The presence of visiblecorrosion does not necessarily r-epresent a; failure of thisSRpoievsbl coroson s emoved duFrin pedoF~armanc of SR 3.8.1.8.

For the purposes oftrending, inter cell (vital and DG batteries) and inter tier (vital and DG baftteies) connecR6tionsG are measured from batter' post to batter; post. Inter rack (vitalbatteries),

inter tier (DG Batteries),

and terminal connec8tions (vital And DGbatteries) are measure-d

  • fro terminal lug to battery post-.Watts Bar-Unit 1B 3.8-61 b DC Sources-Operating B 3.8.4BASESSURVEILLANCEIISEMENTS SR 3.8.4.8.

SR 3.8.4.9 and SR 3.8.1.10 (continued)

The cnneRctin res;hL 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 Mnccoiling 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 eThis SR requires that each vital battery charger be capable of itsa ssoci ated batter; from a capacity or sor~ice discharge test while supplying normal loads, Or alternatively, operating at Iimit for a minimumA of 1 houlrsat a nominal 1215 VDCG. These .rq irmnts are based en the design capacity ofthe chargrs (Ref. 4) and theiF r performanc charaGteristic of curre9nt Imfitoperation for a substantial portion of the recharge period. Batter; charger outputcurrent oi, limited to 110% 125% of the 200 amp rated output. Reharfgirg thebailer' or testing for a minimum of 14or ssfiin to verify the outputcapability Of th chaFrger cncy be susained, that g-cuent limit adjustments areproperly set and that protective Will not pefor.ance at currentlimit settngs.

According to Regulator,'

Guide 1.32 (Ref. 6), the batter,'

charg@ersupply is requir~ed to be based en the largest combined demands of the varioussteady state leads and the charging capacity to restore the batter; from thedesign mcharge state to the fully charged state, irrespective of the statusof the plant during these dem,,and, occu..

Verifying th8 capability of thecharger to operate in a sustained courrent limit condition ensures that theserequirements 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 adequatcharger performnance durinig these 189 month finter~vals.

in addition, thisFrFequency is inten-ded_

to bhe consistent With expected fuel cycle lengths.(continued)

Watts Bar-Unit 1B 3.8-62 DC Sources-Operating B 3.8.4BASES 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 MOIDES 5ad 6 SO.nc it would ro.uiro the G subsystom to b ,Rnoperablo during po.formanc

.of the test. HoweV.. , thi. Sur.eillan.

e Maybe on MODES 1, 2, 3, Or 4 proIided the Vital B÷atte V , risubstituted in accordance With LCO Note 1. Credit mnay be takenfounplanned events that Gatwsf' this SR. Examples of unplanned events may1) Unexpected operational events which cGause the equipment toperformn the function specified by this SUrVeillaAce,

'For WhIchadequate Of equired e is available; a~d2) Post ..rrective maintenance te.sting that requires performance of.... ... .... ..~ ... .. 4.. ., ......" ...H.; u;. emn.;; ; e.,r w;;";".:

'.p'evi-et mte manternare Wtwith mRaintenaneruid t(as required, or pefoFrmed in conjunction maintain OPERBILI TY Or reliability.

-SR3.84.!2 T-his SR requires that each diesel generator battery charger be capable ofrech~arging itro associated battery from a capacity Or GerV9Ge diScharge test whilesupplying normnal loads, Or altebatively, operating at current limit for a of 41 1"2 hos at a nominal 125 This requirement irs based On the designcapacity Of the chargers (Ref. 13) and their perfoFrmance character istic. Of currentlimnit for a substantial 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 toRegulator,'

Guide 1.32 (Ref. 65), the battery .charger supply is, required to bebased on the largest combined demands of the various steady state loads andthe charging capacity to restoeM the battery from the desg minmu c :hargestate to the fully charged state, irrFespective of the status, of the plant during thesedemand occurrences.

Verifying the capability of the charger to operate in asuIstained current limfit GGondition; ensures that these requirements can be6atmfiefld.

(continued)

Watts Bar-Unit 1B 3.8-63Revision 112 DC Sources-Operating B 3.8.4BASESSU IDRVEI IL LA.NCEIGi=

REQlIREENlTS; SR 3.8.4412(ctnud The Sur.'eillance FrFequency is acceptable, given the plant conditions required toperformA the test and thes other administrative controls existing to ensure adequate peFr4frmanle during these 18 month interals.

In addition, thisFrFequency is intended to be consistent With expected fuel cycle lengths..Fo the DG DG electrical subsystem, this Su.ei 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 andwould net otheWrxs challenge safety systems supplied from vital electrical distr&ibution systems.

if available, tfhe G , UG and its assoc.iated PC eir" power subsystem

.may be substituted in .ac .rdan.e.

.ith LO Note 2.Additionally, credit may be taken for unplanned events that satisfy+

this, SRExamp!es of unplanned events may inc'lude:

1) Unexpected operational events which cause the equipment to performRthe function specified by this Surveillance, for which adequate-documnentation of the required performnance is available; and2) Pest cor-rec~tive maintenance testing that requires perfoFrmance of this,Survillnce n oder to restore the component to OPERA.BLE, providedthe 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 thdeswRg (battery' duty cycl,) Of the DG power system,.

The,discharge rate and test length should correspond to wonrst case design dluty cyclrequirements based On Reference.0 and 12.The Surveillance rFrequency of 18 mo~nths is consistent with therecommendations 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 1B 3.8-64Revision 19, 66Amendment 12 DC Sources-Operating B 3.8.4BASESSURVEILLA.hCE REQUIREMENTS SR3..11 (continued)

T-his SR is moedified by two Notes. Noto I allows tho performFance of a modifiedperformnance discharge test in lieu of a servic~e test once per 60 mon~ths.

Themoedified performance discharge test is a simulatod duty cycle consisting of justtwo rates; the one minute rate published for the batter,'

Or the largest current loadof the duty cycle, followed by the test rate employed for the perforancwe test,bonth of %whic-h envelope the duty cycle of the ser~ice testf. SiOnce the am~perehours6 removed by a rated one minute discharge represents a vory' small portionof the battory capacity, tho test rate can be changed to th-at for the performFance tes without 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.rA moedified discharge test is a test of the bailer,'

capacity and its ability to providea 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 dutycycle, in addition to deteMrminin its percentage Of rated capacity.

Initial:conditions for the moedified performance discharge test should be identicall tothose specified for a ser:ice test.Theuron ,,+for Note 2 is that the Sur ..illance may prturb the Vitale~lecrtric~al dis-tribution systemn and- challenge safety systemsR.

How8eve, thisSuryeillance may be performed inMODES I, 2, 3, Or 4 provided that Vital Bailer;LVsusten accordance wiNot e 2. dtC0nIA-,
1. Foyr the OG QC elnctrical ubs.ystems, this sur-i..ancmay be performed in MODES , 2, 3, or 4 incejntinwt LCO 3.8.l.B since the supplied loads are only for the inoealdislgeeao and would not othorwffise challenge safety system leas; wAhic-hare supplied fromR vital electrical distribution systemsr.

if available, the C S DGand its associated DG electrical power subsystemA may be substituted inaccordance With LCO Note 2. Additionally, credit mnay be taken for unplanned events that satisb' this SR. Examples of unplanned events mnay icue1) Unexpected operation-al e-venIts which cause the equipment to performAhe8 umntiAon specified docum~entation of thei dl IIll F I i ibv thi6 Surveiiiance ror Wnic aaeouate.--j .-- --* i..........

7 ... ........* ui Iroqui're penr,,anco s available;

-and(continued)

Wafts Bar-Unit 1B 3.8-65Revision 12Amendment 12 DC Sources-Operating B 3.8.4BASESSUVI\rll ANCE'r SR 3.8.1.13 (contnuod),,rl REQUIREMENTS

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

SR-3.9.4.44 A bailer,'

performance discharge test is, a test of. cnwstant current capacity of abailer,',

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 for32.8.1.123.

Eithe the batter,'

perforaEn;e diechargo test Or the modifiedperfoqrmance discharge testis6 acceptable foFrsatisfYing SR 3.8.4f1.;

however,only the modified rancs e discharge test May be used to satisfy SR 3.5.1.11while satisfying the requiremfents of SR 3.8.1.13 at the same time.The crteria; for this Su, ,feillane are cRonsistent with IErEE= 450(Ref. 9) and IEEE 15 (Ref. 5). Thhese references d rco.meAd that the balefr, bereplaced if its capacity is, belo)w 80% of the- manuf.act'urer rating. A capacity of80% chews that the bailer,'

rate of deterioratio i ncesRg even if there isample 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 andcapacity is 100% o~f the m~anufacturer's rating, the Suryeillance Freuec ' Isreu edt 1_2 months. H'A; A"owever, if the baile~yrshows no degradation but hamsreachedd 8-5%. of its expected life, the Suw.eillance FrFequency is only reduced to21. 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 bailercapacity drops by mor9e than 1 0% relative to its capacity on the preiuperformnance test or wMhen it is > 10%5 belowA the MAnu facturer rating. TheseFFreuencies are c~~wonitent with the recommFn~endations fin IEEE 150 (Ref.91t(continued)

Waits Bar-Unit 1B 3.8-66Revision 19Amendment 12 DC Sources-Operating B 3.8.4BASESSURVEILLANCE REM EN5AI: SR 3.8.4.14 (continued),

This SR is modified by a Note. The reason for the Note is that pefeorming theSurveillance 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 inMODES I, 2, 3, Or 4 in conjuncfion With LCO 3.8.l.B since the supplied leads areonly fr the inoperable diesel generator

,and would net etherise challenge safetysystem leads which are supplied frem vital electri;cia systems.

ifavalable, the C S DG and isassociated DG electrial power subsystem may besubstituted in accor~dance With LCO Note 2. Additionally, credit may be takenfrunplanned events, that satisfy this SR. Examples of unplanned events mnay1 ) Unexpected operational events which cause the equipment to performn the-tunction.

specitied by tiof the required perforn2) Post corrective mainteSurvillncein order tihiG SeFVe aAGe,tor W..c.h adequate ej an4nance testing that requires performnance oftD restore the component to OPERABLE, prorequired, Or performed in conjunction with-to maintain OPERAB-ILITY or reliability.

hiev'-dtcdtne m~aintenance wasm~aintenance required(continued)

Wafts Bar-Unit 1B 3.8-67 Revision 19Amendment 12 DC Sources-Operating B 3.8.4BASESREFERENCES

1. Title 10, Code of Federal Regulations, Part 50, Appendix A, GeneralDesign 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 forNuclear 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 LeadStorage Batteries for Generating Stations and Substations,"

Institute ofElectrical and Electronic Engineers.

6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric PowerSystems for Nuclear Power Plants,"

February 1977, U.S. NuclearRegulatory 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 1974.910.IEEE 150) 1980!11995, "IEFEE Rocommended Practice for Main teAnceGToSting and Replacemnent of Largo Load Storage Battoriesfo Generating Stations and Subsystems,"

Institute of Elec8trical andElec"Rnic Engineers..

IEEE-450-2002, "IEEE Recommended Practice forMaintenance, Testing and Replacement of Vented Lead -Acid Batteries for Stationary Applications,"

Institute of Electrical and Electronics Engineers, Inc.TV4A CGaIulation WBN EEB MS TIl-l 1-0003, "125 VDC Vital Batter' y anCharger Evalation.:"

TVA Calculation EDQ00023620070003, "1 25V DCVital Battern System Analysis."

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

U.S. Nuclear Regulatory Commission, February 1978.(continued)

Watts Bar-Unit 1B 3.8-68 DC Sources-Operating B 3.8.4BASESREFERENCES

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 1B 3.8-69 DC Sources -ShutdownB 3.8.5B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.5 DC Sources -ShutdownBASESBACKGROUND A description of the DC sources is provided in the Bases for LCO 3.8.4, "DCSources -Operating."

APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume that Engineered Safety Feature systems are OPERABLE.

The vital DC electrical power systemprovides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation.

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

The OPERABILITY of the minimum DC electrical power sources duringMODES 5 and 6, and during movement of irradiated fuel assemblies ensuresthat:a. The plant can be maintained in the shutdown or refueling condition for extended periods;b. Sufficient instrumentation and control capability is available formonitoring and maintaining the plant status; andc. Adequate DC electrical power is provided to mitigate eventspostulated during shutdown, such as a fuel handling accident.

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

(continued)

Watts Bar-Unit 1B 3.8-70 DC Sources -ShutdownB 3.8.5BASES (continued)

LCO The 125V Vital DC electrical power subsystems, each vital subsystem channelconsisting of a battery bank, associated battery charger, and the corresponding control equipment and interconnecting cabling within the channel; and the DGDC electrical power subsystems, each consisting of a battery, a battery charger,and the corresponding

'control equipment and interconnecting

cabling, arerequired to be OPERABLE to support required trains of the distribution systemsrequired OPERABLE by LCO 3.8.10, "Distribution Systems -Shutdown" and therequired DGs required OPERABLE by LCO 3.8.2, "AC Sources-Shutdown."

As aminimum, 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 and2B-B) shall be OPERABLE.

This ensures the availability of sufficient DCelectrical power sources to operate the plant in a safe manner and to mitigate theconsequences of postulated events during shutdown (e.g., fuel handlingaccidents).

The LCO is modified by twefour Notes. Note 1 indicates that Vital Battery V maybe substituted for any of the required vital batteries.

However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.

Note 2indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted forrequired vital chargers.

Note 3 indicates that spare DG chargers 1A1, 181, 2A1,or 2B1 may be substituted for required DG chargers.

However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.

Note 4 har beon added to indicates that the C-S DG and itsassociated DC subsystem may be substituted for any of the required DGs.However, the C-S DG and its associated DC subsystem cannot be declaredOPERABLE until it is connected electrically in place of another DG, and it hassatisfied 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 areavailable; (continued)

Watts Bar-Unit 1B 3.8-71 DC Sources -ShutdownB 3.8.5BASESAPPLICABILITY

b. Required features necessary to mitigate the effects of events that can(continued) lead to core damage during shutdown are available; andc. Instrumentation and control capability is available for monitoring andmaintaining the plant in a cold shutdown condition or refueling condition.

The DC electrical power requirements for MODES 1, 2, 3, and 4 are covered inLCO 3.8.4.ACTIONSA.1, A.2.1, A.2.2, A.2.3, and A.2.4If two trains are required by LCO 3.8.10, the remaining train with DC poweravailable may be capable of supporting sufficient systems to allow continuation ofCORE ALTERATIONS and fuel movement.

By allowing the option to declarerequired features inoperable with the associated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with theaffected required features LCO ACTIONS.

In many instances, this option mayinvolve undesired administrative efforts.

Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movementof irradiated fuel assemblies, and operations involving positive reactivity additions).

The Required Action to suspend positive reactivity additions does notpreclude actions to maintain or increase reactor vessel inventory, provided therequired SDM is maintained.

Suspension of these activities shall not preclude completion of actions toestablish a safe conservative condition.

These actions minimize probability ofthe occurrence of postulated events. It is further required to immediately initiateaction to restore the required vital DC electrical power subsystems and tocontinue this action until restoration is accomplished in order to provide thenecessary DC electrical power to the plant safety systems.(continued)

Watts Bar-Unit 1B 3.8-72 DC Sources -ShutdownB 3.8.5BASESACTIONS 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 foractions requiring prompt attention.

The restoration of the required vital DCelectrical power subsystems should be completed as quickly as possible in orderto minimize the time during which the plant safety systems may be withoutsufficient power.B. 1If theone or more required DG DC electrical power subsystem cannot be restoredto OPERABLE status in the associated Completion Time, the associated DGmay 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 3.8.5.1REQUIREMENTS SR 3.8.5.1 requires performance of all Surveillances required by SR 3.8.4.1through SR 3.8.4.4-47.

Therefore, see the corresponding Bases for LCO 3.8.4 fora 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 toprovide the required power supply or otherwise rendered inoperable during theperformance of SRs. It is the intent that these SRs must still be capable of beingmet, 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 1B 3.8-73 Battery Geti-Parameters B 3.8.6B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.6 Battery Gell-Parameters IBASESBACKGROUND 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 vitalDC electrical power subsystem and the diesel generator (DG) batteries.

Adiscussion of these batteries and their OPERABILITY requirements is provided inthe Bases for LCO 3.8.4, "DC Sources -Operating,"

and LCO 3.8.5, "DCSources -Shutdown."

Additional controls for various battery parameters are alsoprovided in Specification 5.7.2.21, Battery Monitoring and Maintenance Program.The battery cells are of flooded lead acid construction with a nominal specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts Per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital batter) the total minimum outputvoltage is 124V and for a 62 cell battery (5th vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or dischar-ging.

Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further chargingper manufacturer's instructions.

Optimal long term performance

however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfate and selfdischarge as discussed in FSAR, Chapter 8 (Ref. 4).APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident (DBA) and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume Engineered SafetyFeature systems are OPERABLE.

The vital DC electrical power system providesnormal and emergency DC electrical power for the emergency auxiliaries, andcontrol and switching during all MODES of operation.

The DG battery systemsprovide DC power for the DGs.The OPERABILITY of the DC subsystems is consistent with the initialassumptions of the accident analyses and is based upon meeting the designbasis of the plant. This includes maintaining at least one train of DC sourcesOPERABLE during accident conditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.Battery eelI-parameters satisfy the Criterion 3 of the NRC Policy Statement.

ILCO 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 safecondition after an anticipated operational occurrence or a postulated DBA.(continued)

Watts Bar-Unit 1B 3.8-74 Battery Ge#-Parameters B 3.8.6IBASESLCO(continued)

EGt Batter parameter limits are conservatively established, allowingcontinued DC electrical system function even with Catogo.y A and B limits notmet. 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 beOPERABLE.

Refer to the Applicability discussion in Bases for LCO 3.8.4 andLCO 3.8.5.ACTIONSA.1, A.2, an4-A.3, C.1, C.2, and C.3With 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 ry A and B li mit..nt Met) but-within the Categor; C limits specified in; Table 3.8.6 1 in the accomnpanyin

_LCO,Ithe eator-y is dograded but mor~e is Still 6uRncIent capacity to ponormF~

tne_ Wendedfunction9.

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 ispe~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 <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (Requirod Action Al). This* check willpoide a quick iniainof the status of the remainder of the batter; cells. Onhour 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) providesassurancGe that during the time needed to restore the parameters to theCategory A and B3 lfimits, the batter,'

is still capable of perfo9Frming its intendedfunction.

A period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 requiredVerification and the assurance that the batter' coil! paramneters are not seVerelydeqraded, this ti~me is; con9sidered reasonable.

The veiiainis reeated at 7(continued)

Watts Bar-Unit 1B 3.8-75 Battery Cell-Parameters B 3.8.6BASESACTIONSA.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.

Th486poriodic verification ie consistent with the normal Frequency of pilot ceilContinued operation i6 erly permirted for 31 days before bastto, onel parameter muot boe rstored to Withir Categrr; A and B3 limits. With the cosidveratio that,while battery caapacity is degraded, sucot capacity misI to rio theinternded fuction and to allow. time to fully .8. tofe the batte ry cell parameters toarmeal limoit, this time is acceptable pcrqi to declarnRg the batery inoperSable.

If one required vital battery or one required DG battery has one or more cellvoltage <2.07 V. the battery is considered degraded.

Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> verification of the required battery charger OPERABILITY is made by monitoring the batteryterminal voltage (SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state ofcharge by monitorinq the 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 intendedfunction.

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 andcontinued operation is permitted for a limited period up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.Since the Required Actions only specify "Perform,"

a failure of SIR 3.8.4.1.

SIR3.8.6.1, SIR 3.8.4.2.

or SR 3.8.6.2 acceptance criteria does not result in thisRequired 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 battervcapacity to perform the intended function and the battery must be declaredinoperable immediately.

B., B.2. D.1. and D.2With oequ Or moa batteries with ona Or More battemp' cl parameters ouir tside theCategory C limits for any coennected coil, sufficient capacity to supply themaximu.ml eAxpcted load requirement is not asrF;; ed and the corresponding VitalDG or DG DG electrical power subsystem must be declaredinprbe Additionally, other potentially extroeFA conditions, such as not completing theRequired Ac-tions of Condition A within the required Completion Timeo vrgelectrel4e temperature Of representatiVe cells falling below 60OF for the vitalbatteries Or 600F for DG_ batteries, are also cause forF immediately declamrig theassciaedVital DG Or _DG DG electrical power subsysteminpeabe One required vital battery with float current > 2 amps or one required DG batterywith float current > 1 amp indicates that a partial discharge of the battery capacityhas occurred.

This may be due to a temporary loss of a battery charger orpossibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity.

Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> verification of the required battery chargerOPERABILITY is made by monitoring the battery terminal voltage.(continued)

Watts Bar-Unit 1B 3.8-76 Battery -eII-Parameters B 3.8.6BASESIf the terminal voltage is found to be less than the minimum established floatvolta-ge there are two possibilities, the battery charqer is inoperable or isoperating in the current limit mode. Condition A and C address chargerinoperability.

If the charger is operating in the current limit mode after 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sthat is an indication that the battery has been substantially discharged and likelycannot perform its required design functions.

The time to return the battery to itsfully 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 previousdischarge, and the recharge characteristic of the battery.

The charge time canbe extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Required Actions B.2 and C.2). The battery must therefore bedeclared inoperable.

If the float voltage is found to be satisfactory but there are one or more batterycells with float voltage less than 2.07 V. the associated "OR" statement inCondition H is applicable and the battery must be declared inoperable immediately.

If float voltage is satisfactory and there are no cells less than 2.07V there is good assurance that, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, the battery will be restored to itsrecharged condition (Required Actions B.2 and C.2) from any discharge thatmight 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 (thesecond 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 previousdischarge and the recharge characteristic of the battery.

Thus there is goodassurance of fully rechar-ging the battery within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, 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 stillgreater than 2.07 V and float voltage is found to be satisfactory, this is notindication of a substantially discharged battery and 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is a reasonable timeprior to declaring the battery inoperable.

Since Required Actions B.1 and C.1 only specify "perform,"

a failure of SR3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in the Required Actionnot 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.3With one required vital or DG battery with one or more cells electrolyte levelabove the top of the plates, but below the minimum established design limits, thebattery still retains sufficient capacity to perform the intended function.

Therefore, the affected battery is not required to be considered inoperable solely as a resultof electrolyte level not met. Within 31 days the minimum established designlimits for electrolyte level must be re-established.

(continued)

Watts Bar-Unit 1B 3.8-76a Battery Gell-Parameters B 3.8.6BASESWith electrolyte level below the top of the plates there is a potential for dryoutand plate degradation.

Required Actions E.1 and E.2 addressed this potential aswell as provisions in Specification 5.7.2.21

.b, Battery Monitoring andMaintenance Program.

They are modified by a Note that indicates they are onlyapplicable if electrolyte level is below the top of the plates. Within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> level isrequired to be restored to above the top of the plates. The Required Action E.2requirement to verify that there is no leakage by visual inspection and theSpecification 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. Theyare performed following the restoration of the electrolyte level to above the top ofthe plates. Based on the results of the manufacturer's recommended testing thebattery may have to be declared inoperable and the affected cell(s) replaced.

F. 1With one required vital or DG battery with pilot cell temperature less than theminimum established design limits, 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is allowed to restore thetemperature to within limits. A low electrolyte temperature limits the current andpower available.

Since the battery is sized with margin, while battery capacity isdegraded, sufficient capacity exists to perform the intended function and theaffected battery is not required to be considered inoperable solely as a result ofthe pilot cell temperature not met.G.1With more than one required vital or more than one DG batteries with batteryparameters not within limits as specified in Conditions A through F there is notsufficient assurance that battery capacity has not been affected to the degreethat the batteries can still perform their required

function, given that redundant batteries are involved.

With redundant batteries involved this potential couldresult 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 mustbe restored to within limits on at least one subsystem within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.H.1With one or more batteries with any battery parameter outside the allowances ofthe Required Actions for Condition A. B. C, D. E, F or G sufficient capacity tosupply the maximum expected load requirement is not assured and thecorresponding battery must be declared inoperable.

Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 Vand float current greater than 2 amps for the vital batteries or 1 amp for the DGbatteries indicates that the battery capacity may not be sufficient to perform theintended functions.

Under these conditions, the battery must be declaredinoperable immediately.

(continued)

Watts Bar-Unit 1B 3.8-76b Battery Getl-Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.1 and SR 3.8.6.2REQUIREMENTS Thus SIR verifies; that Gategeoy A battory' oel! parame~toeF aro concictont withIEEE 450 (Ref. 2), Which rocomm~end6 regular battery' inspectionc (at least oeepor monith) including

voltage, specific
gravity, and oloctrOlyte tem~porature Of pilot-Verifying battery float current while on float charge is used to determine the stateof charge of the battery.

Float charge is the condition in which the charger issupplying the continuous charge required to overcome the internal losses of abattery and maintain the battery in a charged state. The equipment used tomonitor float current must have the necessary accuracy and resolution tomeasure electrical currents in the expected range. The float current requirements are based on the float current indicative of a charged battery.

The 7 dayFrequency is consistent with IEEE-450 (Ref. 2).This SR is modified by a Note that states the float current requirement is notrequired to be met when battery terminal voltage is less than the minimumestablished float voltage of SR 3.8.4.1 or SR 3.8.4.2.

When this float voltage isnot maintained the Required Actions of LCO 3.8.4 ACTION A or E are beingtaken, which provide the necessary and appropriate verifications of the batterycondition.

Furthermore, the float current limit of 2 amps for the vital battery and 1amp for the DG battery is established based on the nominal float voltage valueand is not directly applicable when this voltage is not maintained.

(continued)

Watts Bar-Unit 1B 3.8-76c Battery GeU-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)

The qlurterly inspectio 9f specific gravity and voltage is consistont tIEFEE 450 (Ref.2).

in additi*on, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of a batter; discharge

-1 10V(11 3.5V forF Vital Batter,'

V or-F 106.5P forF PG batterie6) or a batter; ovorchargo

>1 50V (15P -V for Vitalol Bailer; V Or 145VI for -DG- battor9ies),

the batter; mnust be4D -A U +"kI...... Ipn ~ o ".k;.I, rat a,. vnn~ptfrll rMn 0. raofa ~ +s ~ 4 4f'~ ~I(I ! 3.5V for Vital Batter; V or 106.5V for DG batteris),

doa not constitute a battorpdi'charge pro"ided the battery terminal voltage and float current return to protra-nsiet values. This ;nspe-ti-n is a6o9 consistent With !EEE 1-r-50 (Rf.2), whicrecommeInds special inspections following a sovero d icharge or tooRo that no significant degradatiOn of the bailer- occurS as a .. .cnquence Ofsuch discharge Or oVer-harge.

SR-3.3aThis Su'eillancq verific ation that the averago tempratue Of represenn toativ cellstis f 600F for the vital batteries, and 501F for the vit G batteriesI, is oansistnt 1wtha recommtendation of IheE 450 (Ref. 2), that states that the temperature Ofpotenales in representative clatils should be determned se a quadterly basis.';Lower than no~rmal temperatures act to inhibit or reduce batter; capacity.

T-hisSR eRnsure rS that the operating temiperatues Fremain within an aceptable operating range. This limipt ibarsed n manu fac recommendations5.7.2.21.

SA sSR 3.8.6.3 and SR 3.8.6.6Optimal long term battery performance is obtained by maintaining float voltagegreater than or equal to the minimum established design limits Provided by thebattery manufacturer which is 2.20 Vpc. This corresponds to a terminal voltageof 128V for the IDG batteries.

132V for the vital batteries I through IV and 136Vfor the vital battery V. The specified float voltage provides adequate over-potential, which limits the formation of lead sulfate and self discharge.

whichcould eventually render the battery inoperable.

Float voltages in this range orless, but greater than 2.07 Vpc. are addressed in Specification 5.7.2.21.

SRs3.8.6.3 and 3.8.6.6 require verification that the cell float voltages are equal to orgreater than the short term absolute minimum voltage of 2.07V.The Frequency for cell voltagqe verification every 31 days for pilot cell and 92days for each connected cell is consistent with IEEE-450 (Ref. 2).SR 3.8.6.4The limit specified for electrolyte level ensures that the plates suffer no physicaldamage and maintains adequate electron transfer capability.

The minimumdesign electrolyte level is the minimum level indication mark on the battery cellDar. The Frequency is consistent with IEEE-450 (Ref. 2).(continued)

Watts Bar-Unit 1B 3.8-77 Battery Gel4-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)

SR 3.8.6.5This Surveillance verifies that the pilot cell temperature is greater than or equal tothe minimum established design limit (i.e., 60 °F for vital batteries and 50 OF forDG batteries).

Pilot cell electrolyte temperature is maintained above thistemperature to assure the battery can provide the required current and voltage tomeet the design requirements.

Temperature lower than assumed in batterysizinq calculations will not ensure battery capacity is sufficient to perform itsdesign function.

The Frequency is consistent with IEEE-450 (Ref. 2).SR 3.8.6.7A battery performance discharge test is a test of battery capacity using constantcurrent.

The test is intended to determine overall battery degradation due to ageand 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 modifiedperformance discharge test may be used to satisfy the battery service testrequirements of SR 3.8.4.7.A modified performance test is a test of the battery capacity and its ability toprovide a high rate, short duration load (usually the highest rate of the dutycycle). This will often confirm the battery's ability to meet the load duty cycle, inaddition to determining its percentage of rated capacity.

Initial conditions for themodified performance discharge test should be identical to those specified for aservice test.It may consist of must two rates; for instance the one minute rate for the battery orthe largest current load of the duty cycle, followed by the test rate employed forthe 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 verysmall portion of the battery capacity, the test rate can be changed to that for theperformance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge testmust remain above the minimum battery terminal voltage specified in the batteryservice 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 bereplaced if its capacity is below 80% of the manufacturer's rating. A capacity of80% shows that the battery rate of deterioration is increasing, even if there isample capacity to meet the load requirements.

Furthermore, the battery is sizedto meet the assumed duty cycle loads when the battery design capacity reachesthis 80% limit.(continued)

Watts Bar-Unit 1B 3.8-77a Battery Cl-U-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)

SR 3.8.6.7The Surveillance Frequency for this test is normally 60 months. If the batteryshows degradation, or if the battery has reached 85% of its expected life andcapacity is < 100% of the manufacturer's ratinq, the Surveillance Frequency isreduced to 12 months. However, if the battery shows no degradation but hasreached 85% of its expected life, the Surveillance Frequency is only reduced to24 months for batteries that retain capacity

> 100% of the manufacturer's ratingqs.

Degradation is indicated, according to IEEE-450 (Ref. 2), when the batterycapacity drops by more than 10% relative to its capacity on the previousperformance test or when it is > 10% below the manufacturer's rating. TheseFrequencies 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 totake credit for unplanned events that satisfy this SR. Examples of unolanned events may include:1) Unexpected operational events which cause the equipment to performthe function specified by this Surveillance for which adequatedocumentation of the required performance is available:

and2) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in coniunction withmaintenance required to maintain OPERABILITY or reliability.

Tab R .. II flic table doinoAwtoc, tIo liMite On oioctroiý'

level, Peoat veltagoe, and 6pocitictor tFro Elioron"t I Th meaning ot eac-ih catog-rly

i. iicGusedbelow.(continued)

Watts Bar-Unit 1B 3.8-77b Battery GeHl-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS T-lable 3.81 (cnrtinRLud)

Category A defines the normnal paramneterF limit forF each designated pilot coil'ieach bailer;.

The cells selected as pilot cells are those whose temperature,

voltage, and electrolyte specific gravity approximFate the s~tate of charge of theentm~e bate.9eThe Category A limits specified for electrolyte level are based OR nmanufacturer 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 beabove the spec-ifie-d mfaximumA level during equalfizing charge, provided it is; notoverflowing.

These limffits ensure that the plates suffer no physical damage, andthat adequate electFro transfer capability is m~aintafined in the event of transient condtios.

EEE 150 (Ref. 2) recommenAds6 that electrolyt4e level readings shouldbe made only after the battery has been at float charge for at least 7:2 hou rs.The Category A limit specified forfloat voltage i2.13 V per cell. This value ibased On the recommendations of IFEEE 150 (Ref. 2), which states thatprolonged operation of cells -2. 13 ZcanR 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 abatterycharging 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 (25PC+.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 tothe reading; 1 point is subtracof the electrolyte in a cell'nrevape~aeen.

eafor each 3 OF below 77 OF. The specfic gravitys with a loss of water dlue to electrolysis Or(continued)

Watts Bar-Unit 1B 3.8-78 Battery IB 3.8.6BASESSURVEILLANCE REQUIREMENTS Table 3.8.6 1 (continued)

Category B defines the normal paFrameter limits for each connoct1ed ell. ThotermF "connecGted-cell" excludes any batter; coil! that ma" be jumnpered out.The Category B limits specified for electrolyte level and float voltage are thesame as those specified for Category A and have been discussed above. TheCategery B limit specified for specific gravity for each GRnlneted cell is, 1.195(0.020 below the mnanufacturer fully charged, nomninal specific gravity) with theaverage of all connected cells> 1.205 (0.010 below the m~anufacturer fullycharged, nominal specific gravity).

These values, are ba-sed on manufacturer's recommFendations.

The miiumseific gravity value required for each cellensueres that the effects of a hihl chredo newly installed coil! Will net m~askoverall degrad-ation of the battery.Category C defines, the limnits for each coennecrte-d c~ell. These values, althoughreduced, provide assrUanco that sufficient capacity exists to pe~form.

the intenRd-e function and maintain a mnargin Of Safety. When any battery parameter is; eotsid'the Category C limits, the assurance Of sufficient capacity described_

-above nolonger exists, and the battery must be declared inoperable.

The Category C limnits specified for electrel'e level (above the top of the plates48-m.mait-ain ad-equate electron transfer capability.

The&Gatgory C limits for floatvoltage is, based en IEEE 450 (Ref. 2), which states that a coil' voltage of 2.07-VOr below, und~er float conditions, and not caused by elevated temperaturwe of thecell, iniatsinenl!

coiprblems and may reur cl eplacem~ent.

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

Watts Bar-Unit 1B 3.8-79 Battery Gell-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS Tablo 3.9.6 1 (continued) manufactuwrernrcmmended fully charged, F)nominal specific gravity).

in additionto that 10Alimt, itiFequired that the specific graVity forF each connecte coil mus't beno le-ss than 0-0 below-4 the average of all connecated coils. This limit ensueresthat 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 Specificgraviy Fotn eth to Table 3m8.6 1 requires the above mentioned correction forelectrol'Ae level and temperature, with the eXception that level cerrection is notrequired when batter; charging current is2 am;pe On float charge) for Vitalbteisand 4 1.0 amRps for DG b~atterieS.

T-his current provides, in general, aniniainof 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 specificgravity meaur~ement for determining the state Of charge. T-his phenm onidisc-ussr~ed-in !EgE 150 (Ref. 2). Footnote G to Table 32.8.6 1 allRows the floatcharge current to be8 useAd- as an alternate to specific gravity for Up to 31 daysfolwn a bater; recharge.

Within 31 days each connected cell's specificgraviy mus~t be m~easreFd to co4fnfr the state of charge. FollGowig a mninrebatter; recharge (such as equalizing charge that does- not follow a deepdischarge) 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 forG-.enating Stations and Substations."

IEEE Std 450-2002, "IEEERecommended Practice for Maintenance, Testing and ReDlacement ofVented Lead -Acid Batteries for Stationary Applications,"

Institute ofElectrical and Electronics Engineers, Inc.3. IEEE Std 485-1983, "IEEE Recommended Practice for Sizing LarmeLead Storage Batteries for Generatinq Stations and Substations,"

TheInstitute of Electrical and Electronics Engineers, Inc.4. Watts Bar FSAR, Section 8, "Electric Power."Watts Bar-Unit 1B 3.8-80 ATTACHMENT 3Proposed WBN Unit 1 TS Changes (Final Typed)A3-1 DC Sources -Operating 3.8.43.8 ELECTRICAL POWER SYSTEMS3.8.4 DC Sources -Operating LCO 3.8.4Four channels of vital DC and four Diesel Generator (DG) DC electrical powersubsystems shall be OPERABLE.

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

NOTES1. 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 forrequired Vital chargers.
3. Spare DG Chargers 1A1, 1B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
4. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystem.

APPLICABILITY:

MODES 1, 2, 3, and 4.ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Restore vital battery terminal 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />scharger inoperable, voltage to greater than orequal to the minimumestablished float voltage.ANDA.2 Verify vital battery float Once per 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />scurrent < 2 amps.ANDA.3 Restore vital battery charger 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />sto OPERABLE status.B. One required vital battery B.1 Restore vital battery to 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sinoperable.

OPERABLE status.C. One required vital DC C.1 Restore vital DC channel to 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />schannel inoperable for OPERABLE status.reasons other thanCondition A or B.(continued)

Watts Bar-Unit 13.8-24 DC Sources -Operating 3.8.4ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIMED. Required Action and D.1 Be in MODE 3. 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />sassociated Completion ANDTime of Condition A, B, orC not met. D.2 Be in MODE 5. 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />sE. One required DG battery E.1 Restore DG battery terminal 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />scharger inoperable, voltage to greater than orequal to the minimumestablished float voltage.ANDE.2 Verify DG battery float current Once per 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s< 1 amp.ANDE.3 Restore DG battery charger to 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />sOPERABLE status.F. One required DG battery F.1 Restore DG battery to 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sinoperable.

OPERABLE status.G. One required DG DC G.1 Restore DG DC electrical 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />selectrical power subsystem power subsystem toinoperable 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 Gnot met.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.1 Verify vital battery terminal voltage is greater than or 7 daysequal to the minimum established float voltage.SR 3.8.4.2 Verify DG battery terminal voltage is greater than or 7 daysequal to the minimum established float voltage.(continued)

Watts Bar-Unit 13.8-25 DC Sources -Operating 3.8.4SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.4.3 Verify for the vital batteries that the alternate feeder 7 daysbreakers to each required battery charger are open.SR 3.8.4.4 Verify correct breaker alignment and indicated power 7 daysavailability for each DG 125V DC distribution paneland associated battery charger.SR 3.8.4.5 Verify each vital battery charger supplies

> 200 amps 18 monthsat greater than or equal to the minimum established float voltage for -4 hours.ORVerify each vital battery charger can recharge thebattery to the fully charged state within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> whilesupplying the largest combined demands of thevarious continuous steady state loads, after a batterydischarge to the bounding design basis eventdischarge state.SR 3.8.4.6 Verify each DG battery charger supplies

> 20 amps at 18 monthsgreater than or equal to the minimum established floatvoltage for > 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.ORVerify each DG battery charger can recharge thebattery to the fully charged state within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> whilesupplying the largest combined demands of thevarious continuous steady state loads, after a batterydischarge to the bounding design basis eventdischarge state.SR 3.8.4.7 -----------------------

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

1. The modified performance discharge test inSR 3.8.6.7 may be performed in lieu ofSR 3.8.4.7.2. Credit may be taken for unplanned events thatsatisfy this SR.-----------------------------------

18 monthsVerify battery capacity is adequate to supply, andmaintain in OPERABLE status, the requiredemergency loads and any connected nonsafety loadsfor the design duty cycle when subject to a batteryservice test.Watts Bar-Unit 13.8-26 DC Sources -Operating 3.8.4This Page Intentionally BlankWatts Bar-Unit 13.8-27 DC Sources -Operating 3.8.4This Page Intentionally BlankWatts Bar-Unit 13.8-28 DC Sources -Operating 3.8.4This Page Intentionally BlankWaits Bar-Unit 13.8-29 DC Sources-Shutdown 3.8.53.8 ELECTRICAL POWER SYSTEMS3.8.5 DC Sources -ShutdownLCO 3.8.5Vital DC and Diesel Generator (DG) DC electrical power subsystems shall beOPERABLE to support the DC electrical power distribution subsystem(s) required by LCO 3.8.10, "Distribution Systems -Shutdown" and to support theDiesel 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 requiredvital chargers.
3. Spare DG chargers 1A1, 1 B1, 2A1, or 2B1 may be substituted forrequired DG chargers.
4. The C-S DG and its associated DC electrical power subsystem may besubstituted for any of the required DGs and their associated DC electrical power subsystems.

APPLICABILITY:

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

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

subsystems inoperable.

ORA.2.1. Suspend CORE Immediately ALTERATIONS.

ANDA.2.2 Suspend movement of Immediately irradiated fuel assemblies.

I_ (continued)

Watts Bar-Unit 13.8-30 DC Sources-Shutdown 3.8.5ACTIONSCONDITION REQUIRED ACTION COMPLETION TIMEA. (continued)

ANDA.2.3 Initiate action to suspend Immediately operations involving positivereactivity additions.

ANDA.2.4 Initiate action to restorerequired 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 13.8-31 DC Sources-Shutdown 3.8.5SURVEILLANCE 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, thefollowing SRs are applicable:

In accordance withapplicable SRsSR 3.8.4.1SR 3.8.4.2SR 3.8.4.3SR 3.8.4.4SR 3.8.4.5SR 3.8.4.6SR 3.8.4.7Watts Bar-Unit 13.8-32 Battery Parameters 3.8.63.8 ELECTRICAL POWER SYSTEMS3.8.6 Battery Parameters LCO 3.8.6Battery parameters for required 125 V vital batteries and 125 V diesel generator (DG) batteries shall be within the limits.When associated DC electrical power subsystems and DGs are required to beOPERABLE.

APPLICABILITY:

ACTIONS------------------------

NOTE-Separate Condition entry is allowed for each battery.CONDITION REQUIRED ACTION COMPLETION TIMEA. One required vital battery A.1 Perform SR 3.8.4.1.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith one or more batterycells float voltage < 2.07 V. ANDA.2 Perform SR 3.8.6.1.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sANDA.3 Restore affected cell float 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />svoltage >- 2.07 V.B. One required vital battery B.1 Perform SR 3.8.4.1.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith float current > 2 amps.ANDB.2 Restore vital battery float 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />scurrent to < 2 amps.C. One required DG battery C.1 Perform SR 3.8.4.2.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith one or more batterycells float voltage < 2.07 V. ANDC.2 Perform SR 3.8.6.2.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sANDC.3 Restore affected cell float 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />svoltage > 2.07 V.(continued)

Watts Bar-Unit 13.8-33 Battery Parameters 3.8.6CONDITION REQUIRED ACTION COMPLETION TIMED. One required DG battery D.1 Perform SR 3.8.4.2.

2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />swith float current > 1 amp.ANDD.2 Restore DG battery float 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />scurrent to < 1 amp.E. One required battery ------------------

NOTE ----------

with one or more cells withelectrolyte level less than Required Actions E.1 and E.2 are onlyelectt leelalessthan applicable if electrolyte level was belowminimum established the top of plates.design limits.E.1 Restore electrolyte level to 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />sabove top of plates.ANDE.2 Verify no evidence of leakage.

12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />sANDE.3 Restore electrolyte level to 31 daysgreater than or equal tominimum established designlimits.F. One required battery F.1 Restore battery pilot cell 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />swith pilot cell electrolyte temperature to greater than ortemperature 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 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sbatteries with battery within limits.parameters not within limits.ORMore than one required DGbatteries with batteryparameters not within limits.(continued)

Watts Bar-Unit 13.8-34 Battery Parameters 3.8.6ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIMEH. 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.OROne required vital batterywith one or more batterycells float voltage < 2.07 Vand float current > 2 amps.OROne required DG batterywith one or more batterycells float voltage < 2.07Vand float current > 1 amp.SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.8.6.1 -----NOTE ---------------

Not required to be met when vital battery terminalvoltage is less than the minimum established floatvoltage of SR 3.8.4.1.Verify each vital battery float current is < 2 amps. 7 daysSR 3.8.6.2 -----------------------

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

Not required to be met when DG battery terminalvoltage is less than the minimum established floatvoltage of SR 3.8.4.2.Verify each DG battery float current is < 1 amp. 7 daysSR 3.8.6.3 Verify each required vital and DG battery pilot cell. 31 daysfloat voltage is > 2.07 V.(continued)

Watts Bar-Unit 13.8-35 Battery Parameters 3.8.6SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.8.6.4 Verify each required vital and DG battery connected 31 dayscell electrolyte level is greater than or equal tominimum established design limits.SR 3.8.6.5 Verify each required vital and DG battery pilot cell 31 daystemperature is greater than or equal to minimumestablished design limits.SR 3.8.6.6 Verify each required vital and DG battery connected 92 dayscell float voltage is > 2.07 V.SR 3.8.6.7 ----------

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

Credit may be taken for unplanned events thatsatisfy this SR.Verify battery capacity is > 80% of the manufacturer's 60 monthsrating when subjected to a performance discharge test or a modified performance discharge test. AND12 months whenbattery showsdegradation, or hasreached 85% of theexpected life withcapacity

< 100% ofmanufacturer's ratingAND24 months whenbattery has reached85% of the expectedlife with capacity? 100% ofmanufacturer's ratingWatts Bar-Unit 13.8-36 Procedures, Programs and Manuals5.75.7 Procedures,

Programs, and Manuals5.7.2.21 Battery Monitoring and Maintenance ProgramThis Program provides controls for battery restoration and maintenance.

The programshall be in accordance with IEEE Standard (Std) 450-2002, "IEEE Recommended Practice for Maintenance,

Testing, and Replacement of Vented Lead-Acid Batteries forStationary Applications,"

as endorsed by Regulatory Guide 1.129, Revision 2 (RG), withRG 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 afterconducting discharge tests.2. RG 1.129, Regulatory Position 1, Subsection 2, "References,"

is notapplicable 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 thebattery."

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 currenthas stabilized at the charging voltage for three consecutive hourlymeasurements, the battery is near full charge. These measurements shall be made after the initially high charging current decreases sharplyand 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 ofeach 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 batterycells is ? 2.13V when the float voltage of a battery cell has been found tobe < 2.13V;3. Actions to equalize and test battery cells that had been discovered withelectrolyte level below the top of the plates;4. Limits on average electrolyte temperature, battery connection resistance, and battery terminal voltage; and5. A requirement to obtain specific gravity readings of all cells at eachdischarge test, consistent with manufacturer recommendations.

Watts Bar-Unit 15.0-25b ATTACHMENT 4Proposed WBN Unit I TS Bases Changes (Final Typed)(For Information Only)A4-1 DC Sources-Operating B 3.8.4B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.4 DC Sources -Operating BASESBACKGROUND The station DC electrical power system provides the AC emergency powersystem with control power. It also provides both motive and control power toselected safety related equipment and preferred AC vital bus power (viainverters).

As required by 10 CFR 50, Appendix A, GDC 17 (Ref.1),

the DCelectrical power system is designed to have sufficient independence, redundancy, and testability to perform its safety functions, assuming a singlefailure.

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 safetyfunction is to provide control power for engineered safety features equipment, emergency

lighting, vital inverters, and other safety-related DC poweredequipment for the entire unit. The system capacity is sufficient to supply theseloads and any connected nonsafety loads during normal operation and to permitsafe 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 asingle 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 areassociated 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 theequipment of all other channels so that a single failure in one channel will notcause a failure in another channel.

Each channel consists of a battery chargerwhich supplies normal DC power, a battery for emergency DC power, and abattery board which facilitates load grouping and provides circuit protection.

These four channels are used to provide emergency power to the 120V AC vitalpower system which furnishes control power to the reactor protection system. Noautomatic connections are used between the four redundant channels.

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

Watts Bar-Unit 1B 3.8-54 DC Sources-Operating B 3.8.4BASESBACKGROUND 125V Vital DC Electrical Power Subsystem (continued)

Additionally, battery boards 1, 11, 111, and IV have manual access to the fifth vitalbattery system. The fifth 125V DC Vital Battery System is intended to serve as areplacement 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 ofoperation.

Each of the vital DC electrical power subsystems provide the control power for itsassociated Class 1 E AC power load group, 6.9 kV switchgear, and 480V loadcenters.

The vital DC electrical power subsystems also provide DC electrical power to the inverters, which in turn power the AC vital buses. Additionally, theypower the emergency DC lighting system.The vital DC power distribution system is described in more detail in Bases forLCO 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 loadcontinuously for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> in the event of a loss of all AC power (stationblackout) without an accident or for 30 minutes with an accident considering asingle failure.

Load shedding of non-required loads will be performed to achievethe required coping duration for station blackout conditions.

Each 125V DC vital battery is separately housed in a ventilated room apart fromits charger and distribution

centers, except for Vital Battery V. Each subsystem is located in an area separated physically and electrically from the othersubsystem to ensure that a single failure in one subsystem does not cause afailure in a redundant subsystem.

There is no. sharing between redundant Class1 E subsystems, such as batteries, battery chargers, or distribution panels.The batteries for the vital DC electrical power subsystems are sized to producerequired capacity at 80% of nameplate rating, corresponding to warranted capacity at end of life cycles, de-rated for minimum ambient temperature and the100% design demand. The criteria for sizing large lead storage batteries aredefined in IEEE-485 (Ref.5).The battery cells are of flooded lead acid construction with a nominal specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital battery) the total minimum outputvoltage is 124V and for a 62 cell battery (5th vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or discharging.

Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further chargingper manufacturer's instructions.

Optimal long term performance

however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfate and selfdischarge.

(continued)

Watts Bar-Unit 1B 3.8-55 DC Sources-Operating B 3.8.4BASESBACKGROUND 1 25V Vital DC Electrical Power Subsystem (continued)

Each Vital DC electrical power subsystem has ample power output capacity forthe steady state operation of connected loads required during normal operation, while at the same time maintaining its battery bank fully charged.

Each batterycharger also has sufficient capacity to restore the battery bank from the designminimum charge to its fully charged state within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (with accident loadsbeing supplied) following a 30 minute AC power outage and in approximately 36hours (while supplying normal steady state loads following a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> AC poweroutage) (Ref. 6).The battery charger is normally in the float-charge mode. Float-charge is thecondition in which the charger is supplying the connected loads and the batterycells are receiving adequate current to optimally charge the battery.

This assuresthe internal losses of a battery are overcome and the battery is maintained in afully charged state.When desired, the charger can be placed in the equalize mode. The equalizemode is at a higher voltage than the float mode and charging current iscorrespondingly higher. The battery charger is operated in the equalize modeafter a battery discharge or for routine maintenance.

Following a batterydischarge, the battery recharge characteristic accepts current at the current limitof the battery charger (if the discharge was significant, e.g., following a batteryservice test) until the battery terminal voltage approaches the charger voltagesetpoint.

Charging current then reduces exponentially during the remainder ofthe recharge cycle. Lead calcium batteries have recharge efficiencies of greaterthan 91%, so once at least 110% of the ampere-hours discharged have beenreturned, the battery capacity would be restored to the same condition as it wasprior to the discharge.

This can be monitored by direct observation of theexponentially 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 andfield-flash circuits have power supplied from their respective 125V distribution panel. The normal supply of DC current is from the associated charger.

Thebattery provides control and field-flash power when the charger is unavailable.

The charger supplies the normal DC loads, maintains the battery in a fullycharged condition, and recharges (480V AC available) the battery whilesupplying the required loads regardless of the status of the unit. The batteries are physically and electrically independent.

The battery has sufficient capacitywhen fully charged to supply required loads for a minimum of 30 minutesfollowing a loss of normal power. Each battery is normally required to supplyloads during the time interval between loss of normal feed to its charger and thereceipt of emergency power to the charger from its respective DG.Watts Bar-Unit 1B 3.8-56 DC Sources-Operating B 3.8.4BASESAPPLICABLE SAFETY ANALYSESThe initial conditions of Design Basis Accident (DBA) andtransient 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 DCelectrical power for the emergency auxiliaries, and control power for switching during all MODES of operation.

The DG battery systems provide DC power forthe DGs. The OPERABILITY of the DC sources is consistent with the initialassumptions of the accident analyses and is based upon meeting the designbasis of the plant. This includes maintaining the DC sources OPERABLE duringaccident conditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.The DC sources satisfy Criterion 3 of the NRC Policy Statement.

LCOFour 125V vital DC electrical power subsystems, each vital subsystem channelconsisting 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 eachconsisting of a battery, a dual battery charger assembly, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE toensure the availability of the required power to shut down the reactor andmaintain it in a safe condition after an anticipated operational occurrence (AOO)or a postulated DBA. Loss of any DC electrical power subsystem does notprevent the minimum safety function from being performed (Ref. 4).An OPERABLE vital DC electrical power subsystem requires all requiredbatteries and respective chargers to be operating and connected to theassociated DC buses.The LCO is modified by four Notes. Note 1 indicates that Vital Battery V may besubstituted for any of the required vital batteries.

However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.

Note2 indicates that spare vital chargers 6-S, 7-S, 8-S, or 9-S may be substituted forrequired vital chargers.

Note 3 indicates that spare DG chargers 1Al, 1 B1, 2A1,or 2B1 may be substituted for required DG chargers.

However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.

Note 4 indicates that the C-S DG and its associated DCsubsystem may be substituted for any of the required DGs. However, the C-SDG and its associated DC subsystem cannot be declared OPERABLE until it isconnected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.

IWatts Bar-Unit 1B 3.8-57 DC Sources-Operating B 3.8.4BASESAPPLICABILITY The four vital DC electrical power sources and four DG DC electrical powersources are required to be OPERABLE in MODES 1, 2, 3, and 4 to ensure safeplant operation and to ensure that:a. Acceptable fuel design limits and reactor coolant pressure boundarylimits are not exceeded as a result of AOs or abnormal transients; andb. Adequate core coolingis

provided, and containment integrity and othervital functions are maintained in the event of a postulated DBA.The DC electrical power requirements for MODES 5 and 6 are addressed in theBases for LCO 3.8.5, "DC Sources -Shutdown."

ACTIONS A.1, A.2, A.3, E.1, E.2, and E.3Conditions 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).

TheACTIONS provide a tiered response that focuses on returning the battery to thefully charged state and restoring a fully qualified charger to OPERABLE status ina 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 <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. 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 floatvoltage.

Restoring the battery terminal voltage to greater than or equal to theminimum established float voltage provides good assurance that, within 12hours, 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 currentportion (the second part) of its recharge cycle. The time to return a battery to itsfully charged state under this condition is simply a function of the amount of theprevious discharge and the recharge characteristic of the battery.

Thus there is.good assurance of fully recharging the battery within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, avoiding apremature shutdown with its own attendant risk.If battery terminal float voltage cannot be restored to greater than or equal to theminimum established float voltage within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and the charger is notoperating in the current-limiting mode, a faulty charger is indicated.

A faultycharger that is incapable of maintaining established battery terminal float voltagedoes not provide assurance that it can revert to and operate properly in thecurrent limit mode that is necessary during the recovery period following a batterydischarge event that the DC system is designed for.If the charger is operating in the current limit mode after 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> that is anindication that the battery is partially discharged and its capacity margins will bereduced.

The time to return the battery to its fully charged condition in this case isa function of the battery charger capacity, the amount of loads on the associated (continued)

Watts Bar-Unit 1B 3.8-58 DC Sources-Operating B 3.8.4BASESACTIONS DC system, the amount of the previous discharge, and the rechargecharacteristic of the battery.

The charge time can be extensive, and there is notadequate assurance that it can be recharged within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.Required Actions A.2 and E.2 require that the battery float current be verified lessthan or equal to 2 amps for the vital battery and less than or equal to 1 amp forthe DG battery.

This indicates that, if the battery had been discharged as theresult of the inoperable battery charger, it is now fully capable of supplying themaximum expected load requirement.

The 2 amp value for the vital battery andthe 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 theinitial 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period the battery float current is not less than or equal to 2 ampsfor the vital battery or 1 amp for the DG battery, then this indicates there may beadditional battery problems and the battery must be declared inoperable.

Required Actions A.3 and E.3 limit the restoration time for the inoperable batterycharger to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This action is applicable if an alternate means of restoring battery terminal voltage to greater than or equal to the minimum established floatvoltage has been used (e.g., balance of plant non-Class 1 E battery charger).

The72 hour Completion Time reflects a reasonable time to effect restoration of thequalified battery charger to OPERABLE status.B.1 and F.1Conditions B.1 and F.1 represent one channel (subsystem) with one batteryinoperable.

With one battery inoperable, the DC bus is being supplied by theOPERABLE battery charger.

Any event that results in a loss of the AC bussupporting 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 behampered 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 dieselgenerator output circuit breakers, etc.) will likely rely upon the battery.

In additionany DC load transients that are beyond the capability of the battery charger andnormally require the assistance of the battery will not be able to be broughtonline. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 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.) areidentified in Specifications 3.8.4, 3.8.5, and 3.8.6 together with additional specificCompletion Times.C.1 and G.1Conditions C.1 and G.1 represent a loss of one DC electrical power subsystem tocompletely respond to an event, and a potential loss of ability to remainenergized during normal operation.

It is therefore, imperative that the operator's attention focus on stabilizing the unit, minimizing the potential for complete lossof DC power to the affected subsystem.

The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limit is consistent with theallowed time for an inoperable DC distribution subsystem.

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

Watts Bar-Unit 1B 3.8-59 DC Sources-Operating B 3.8.4BASESACTIONS DC electrical power subsystem, the remaining DC electrical power subsystem has the capacity to support a safe shutdown and to mitigate an accidentcondition.

Since a subsequent worst case single failure could, however, result inthe loss of the minimum necessary DC electrical subsystems to mitigate a worstcase accident, continued power operation should not exceed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The 2 hourCompletion Time is based on Regulatory Guide 1.93 (Ref. 8) and reflects areasonable time to assess unit status as a function of the inoperable DCelectrical power subsystem and, if the DC electrical power subsystem is notrestored to OPERABLE status, to prepare to effect an orderly and safe unitshutdown.

D.1 and D.2If the inoperable Vital DC electrical power subsystem cannot be restored toOPERABLE status within the required Completion Time, the plant must bebrought to a MODE in which the LCO does not apply. To achieve this status, theplant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in anorderly manner and without challenging plant systems.

The Completion Time tobring the plant to MODE 5 is consistent with the time required in Regulatory Guide 1.93 (Ref.8).H.1If the DG DC electrical power subsystem cannot be restored to OPERABLEstatus 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 RequiredActions for an inoperable DG, LCO 3.8.1, "AC Sources-Operating."

SURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps toensure the effectiveness of the battery chargers, which support the ability of thebatteries to perform their intended function.

Float charge is the condition inwhich the charger is supplying the continuous charge required to overcome theinternal losses of a battery (or battery cell) and maintain the battery (or a batterycell) in a fully charged state while supplying the continuous steady state loads ofthe associated DC subsystem.

On float charge, batterycells will receiveadequate current to optimally charge the battery.

The voltage requirements arebased on the nominal design voltage of the battery and are consistent with theminimum float voltage established by the battery manufacturer.

For example theminimum nominal terminal voltage for the 5th Vital Battery is 136V (62 cells times2.20 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 DGbatteries is 128V (58 cells times 2.20 Vpc). These voltage levels maintain thebattery plates in a condition that supports maintaining the grid life.(continued)

Watts Bar-Unit 1B 3.8-60 DC Sources-Operating B 3.8.4BASESSURVEILLANCE The voltage requirements listed above are based on the critical design voltage ofREQUIREMENTS the battery and are consistent with the initial voltages assumed in the batterysizing calculations.

The 7 day Frequency is consistent with manufacturer recommendations and IEEE-450 (Ref. 9).SR 3.8.4.3Verifying that for the vital batteries that the alternate feeder breakers to eachrequired battery charger is open ensures that independence between the powertrains is maintained.

The 7-day Frequency is based on engineering

judgment, isconsistent with procedural controls governing breaker operation, and ensurescorrect breaker position.

SR 3.8.4.4This SR demonstrates that the DG 125V DC distribution panel and associated charger are functioning

properly, with all required circuit breakers closed andbuses energized from normal power. The 7 day Frequency takes into accountthe redundant DG capability and other indications available in the control roomthat will alert the operator to system malfunctions.

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

According to Regulatory Guide 1.32 (Ref. 6), the battery charger supply isrecommended to be based on the largest combined demands of the varioussteady state loads and the charging capacity to restore the battery from thedesign minimum charge state to the recharged state, irrespective of the status ofthe unit during these demand occurrences.

Verifying the capability of the chargerto 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 chargerbe capable of supplying 200 amps (20 amps for the DG battery charger) at theminimum established float voltage for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Recharging the battery or testingfor a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is sufficient to verify the output capability of the chargercan be sustained, that current limit adjustments are properly set and thatprotective devices will not inhibit performance at current limit settings.

The other option requires that each battery charger be capable of recharging thebattery after a service test coincident with supplying the largest coincident demands of the various continuous steady state loads (irrespective of the statusof the plant during which these demands occur). This level of loading may notnormally be available following the battery service test and will need to besupplemented with additional loads. The duration for this test may be longer thanthe charger sizing criteria since the battery recharge is affected by float voltage,temperature, and the exponential decay in charging current.

The battery isrecharged 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 toperform the test and the other administrative controls existing to ensure adequatecharger performance during these 18 month intervals.

In addition, thisFrequency is intended to be consistent with expected fuel cycle lengths.(continued)

Watts Bar-Unit 1B 3.8-61 DC Sources-Operating B 3.8.4BASESSURVEILLANCE SR 3.8.4.7REQUIREMENTS A battery service test is a special test of battery capability, as found, to satisfy thedesign requirements (battery duty cycle) of the DC electrical power system. Thedischarge rate and test length should correspond to worst case design duty cyclerequirements 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), whichstate 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 modifiedperformance discharge test in lieu of a service test. The modified performance discharge test is a simulated duty cycle consisting of just two rates; the oneminute 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 whichenvelope the duty cycle of the service test. Since the ampere-hours removed bya rated one minute discharge represents a very small portion of the batterycapacity, the test rate can be changed to that for the performance test withoutcompromising the results of the performance discharge test. The batteryterminal voltage for the modified performance discharge test should remainabove the minimum battery terminal voltage specified in the battery service testfor 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 performthe function specified by this Surveillance, for which adequatedocumentation of the required performance is available; and2) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in conjunction withmaintenance required to maintain OPERABILITY or reliability.

Watts Bar-Unit 1B 3.8-62 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-63 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-64 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-65 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-66 DC Sources-Operating B 3.8.4BASESPage Intentionally BlankWatts Bar-Unit 1B 3.8-67 DC Sources-Operating B 3.8.4BASESREFERENCES

1. Title 10, Code of Federal Regulations, Part 50, Appendix A, GeneralDesign 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 forNuclear 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 LeadStorage Batteries for Generating Stations and Substations,"

Institute ofElectrical and Electronic Engineers.

6. Regulatory Guide 1.32, "Criteria for Safety-Related Electric PowerSystems for Nuclear Power Plants,"

February 1977, U.S. NuclearRegulatory 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, Testingand Replacement of Vented Lead -Acid Batteries for Stationary Applications,"

Institute of Electrical and Electronics Engineers, Inc.10. TVA Calculation EDQ00023620070003, "125V DC Vital Battery SystemAnalysis."

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

U.S. Nuclear Regulatory Commission, February 1978.(continued)

Watts Bar-Unit 1B 3.8-68 DC Sources-Operating B 3.8.4BASESREFERENCES

12. iVA Calculation WBN EEB-MS-TI1 1-0062, "125 V DC Diesel Generator (continued)

Control Power System Evaluation"

13. Watts Bar FSAR, Section 8.3.1, "AC Power System."Watts Bar-Unit 1B 3.8-69 DC Sources -ShutdownB 3.8.5B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.5 DC Sources -ShutdownBASESBACKGROUND A description of the DC sources is provided in the Bases for LCO 3.8.4, "DCSources -Operating."

APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume that Engineered Safety Feature systems are OPERABLE.

The vital DC electrical power systemprovides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during all MODES of operation.

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

The OPERABILITY of the minimum DC electrical power sources duringMODES 5 and 6, and during movement of irradiated fuel assemblies ensuresthat:a. The plant can be maintained in the shutdown or refueling condition for extended periods;b. Sufficient instrumentation and control capability is available formonitoring and maintaining the plant status; andc. Adequate DC electrical power is provided to mitigate eventspostulated during shutdown, such as a fuel handling accident.

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

(continued)

Watts Bar-Unit 1B 3.8-70 DC Sources -ShutdownB 3.8.5BASESLCO The 125V Vital DC electrical power subsystems, each vital subsystem channelconsisting of a battery bank, associated battery charger, and the corresponding control equipment and interconnecting cabling within the channel; and the DGDC electrical power subsystems, each consisting of a battery, a battery charger,and the corresponding control equipment and interconnecting

cabling, arerequired to be OPERABLE to support required trains of the distribution systemsrequired OPERABLE by LCO 3.8.10, "Distribution Systems -Shutdown" and therequired DGs required OPERABLE by LCO 3.8.2, "AC Sources-Shutdown."

As aminimum, one vital DC electrical power train (i.e., Channels I and Ill, or II and IV)and two DG DC electrical power subsystems (i.e., 1A-A and 2A-A or 1B-B and2B-B) shall be OPERABLE.

This ensures the availability of sufficient DCelectrical power sources to operate the plant in a safe manner and to mitigate theconsequences of postulated events during shutdown (e.g., fuel handlingaccidents).

The LCO is modified by four Notes. Note 1 indicates that Vital Battery V may besubstituted for any of the required vital batteries.

However, the fifth batterycannot be declared OPERABLE until it is connected electrically in place ofanother battery and it has satisfied applicable Surveillance Requirements.

Note 2indicates that spare vital chargers 6-S, 7-S, 8-S or 9-S may be substituted forrequired vital chargers.

Note 3 indicates that spare DG chargers 1A1, 1B1, 2A1,or 2B1 may be substituted for required DG chargers.

However, the sparecharger(s) cannot be declared OPERABLE until it is connected electrically inplace of another charger, and it has satisfied applicable Surveillance Requirements.

Note 4 indicates that the C-S DG and its associated DCsubsystem may be substituted for any of the required DGs. However, the C-SDG and its associated DC subsystem cannot be declared OPERABLE until it isconnected electrically in place of another DG, and it has satisfied applicable Surveillance Requirements.

(continued)

Watts Bar-Unit 1B 3.8-71 DC Sources -ShutdownB 3.8.5BASES (continued)

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 areavailable;

b. Required features necessary to mitigate the effects of events that canlead to core damage during shutdown are available; andc. Instrumentation and control capability is available for monitoring andmaintaining the plant in a cold shutdown condition or refueling condition.

The DC electrical power requirements for MODES 1, 2, 3, and 4 are covered inLCO 3.8.4.ACTIONS A.1, A.2.1, A.2.2, A.2.3, and A.2.4If two trains are required by LCO 3.8.10, the remaining train with DC poweravailable may be capable of supporting sufficient systems to allow continuation ofCORE ALTERATIONS and fuel movement.

By allowing the option to declarerequired features inoperable with the associated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with theaffected required features LCO ACTIONS.

In many instances, this option mayinvolve undesired administrative efforts.

Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movementof irradiated fuel assemblies, and operations involving positive reactivity additions).

The Required Action to suspend positive reactivity additions does notpreclude actions to maintain or increase reactor vessel inventory, provided therequired SDM is maintained.

Suspension of these activities shall not preclude completion of actions toestablish a safe conservative condition.

These actions minimize probability ofthe occurrence of postulated events. It is further required to immediately initiateaction to restore the required vital DC electrical power subsystems and tocontinue this action until restoration is accomplished in order to provide thenecessary DC electrical power to the plant safety systems.(continued)

Watts Bar-Unit 1B 3.8-72 DC Sources -ShutdownB 3.8.5BASES (continued)

ACTIONSA.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 foractions requiring prompt attention.

The restoration of the required vital DCelectrical power subsystems should be completed as quickly as possible in orderto minimize the time during which the plant safety systems may be withoutsufficient power.B. 1If one or more required DG DC electrical power subsystem cannot be restored toOPERABLE status in the associated Completion Time, the associated DG maybe 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 REQUIREMENTS SR 3.8.5.1SR 3.8.5.1 requires performance of all Surveillances required by SR 3.8.4.1through SR 3.8.4.7.

Therefore, see the corresponding Bases for LCO 3.8.4 for adiscussion 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 toprovide the required power supply or otherwise rendered inoperable during theperformance of SRs. It is the intent that these SRs must still be capable of beingmet, 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 1B 3.8-73 Battery Parameters B 3.8.6B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.6 Battery Parameters BASESIBACKGROUND This LCO delineates the limits on battery float current, electrolyte temperature, electrolyte level, and cell float voltage, for both the 125V vital DC electrical powersubsystem and the diesel generator (DG) batteries.

A discussion of thesebatteries and their OPERABILITY requirements is provided in the Bases for LCO3.8.4, "DC Sources -Operating,"

and LCO 3.8.5, "DC Sources -Shutdown."

Additional controls for various battery parameters are also provided inSpecification 5.7.2.21, Battery Monitoring and Maintenance Program.The battery cells are of flooded lead acid construction with a nominal specificgravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07Volts per cell (Vpc). For a 58 cell battery (DG battery) the total minimum outputvoltage is 120V, for a 60 cell battery (vital battery) the total minimum outputvoltage is 124V and for a 62 cell battery (51h vital battery) the total minimumoutput voltage is 128V. The open circuit voltage is the voltage maintained whenthere is no charging or discharging.

Once fully charged the battery cell willmaintain approximately 97% of its capacity for 30 days without further chargingper manufacturer's instructions.

Optimal long term performance

however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfate and selfdischarge as discussed in FSAR, Chapter 8 (Ref. 4).APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident (DBA) and transient analyses inthe FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assume Engineered SafetyFeature systems are OPERABLE.

The vital DC electrical power system providesnormal and emergency DC electrical power for the emergency auxiliaries, andcontrol and switching during all MODES of operation.

The DG battery systemsprovide DC power for the DGs.The OPERABILITY of the DC subsystems is consistent with the initialassumptions of the accident analyses and is based upon meeting the designbasis of the plant. This includes maintaining at least one train of DC sourcesOPERABLE during accident conditions in the event of:a. An assumed loss of all offsite AC power or all onsite AC power; andb. A worst case single failure.Battery parameters satisfy the Criterion 3 of the NRC Policy Statement.

ILCO Battery parameters must remain within acceptable limits to ensure availability ofthe required DC power to shut down the reactor and maintain it in a safecondition after an anticipated operational occurrence or a postulated DBA.(continued)

Watts Bar-Unit 1B 3.8-74 Battery Parameters B 3.8.6BASESLCO Battery parameter limits are conservatively established, allowing continued (continued)

DC electrical system function even with limits not met. Additional preventative maintenance,

testing, and monitoring are conducted in accordance withSpecification 5.7.2.21, Battery Monitoring and Maintenance Program.APPLICABILITY The battery parameters are required solely for the support of the associated vitalDC and DG DC electrical power subsystems.

Therefore, battery parameter limitsare 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, A.3, C.1, C.2, and C.3If one required vital battery or one required DG battery has one or more cellvoltage < 2.07 V, the battery is considered degraded.

Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> verification of the required battery charger OPERABILITY is made by monitoring the batteryterminal voltage (SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state ofcharge by monitoring the battery float charge current (SR 3.8.6.1 or SR 3.8.6.2).

This assures that there is still sufficient battery capacity to perform the intendedfunction.

Therefore, the affected battery is not required to be considered inoperable solely as a result of one or more cells in one battery < 2.07 V andcontinued operation is permitted for a limited period up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.Since the Required Actions only specify "perform,"

a failure of SR 3.8.4.1, SR3.8.6.1, SR 3.8.4.2, or SR 3.8.6.2 acceptance criteria does not result in thisRequired 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 SR 3.8.6.1 orSR 3.8.6.2 is failed then there is not assurance that there is still sufficient batterycapacity to perform the intended function and the battery must be declaredinoperable immediately.

B.1, B.2, D.1, and D.2One required vital battery with float current > 2 amps or one required DG batterywith float current > 1 amp indicates that a partial discharge of the battery capacityhas occurred.

This may be due to a temporary loss of a battery charger orpossibly due to one or more battery cells in a low voltage condition reflecting some loss of capacity.

Within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> verification of the required battery chargerOPERABILITY is made by monitoring the battery terminal voltage.If the terminal voltage is found to be less than the minimum established floatvoltage there are two possibilities, the battery charger is inoperable or isoperating in the current limit mode. Conditions A and C addresses chargerinoperability.

If the charger is operating in the current limit mode after 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sthat is an indication that the battery has been substantially discharged and likelycannot perform its required design functions.

The time to return the battery to itsfully 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(continued)

Watts Bar-Unit 1B 3.8-75 Battery Parameters B 3.8.6BASESACTIONS B.1, B.2, D.1 and D.2(continued) discharge, and the recharge characteristic of the battery.

The charge time canbe extensive, and there is not adequate assurance that it can be recharged within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> (Required Actions B.2 and C.2). The battery must therefore bedeclared inoperable.

If the float voltage is found to be satisfactory but there are one or more batterycells with float voltage less than 2.07 V, the associated "OR" statement inCondition H is applicable and the battery must be declared inoperable immediately.

If float voltage is satisfactory and there are no cells less than 2.07V there is good assurance that, within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, the battery will be restored to itsrecharged condition (Required Actions B.2 and C.2) from any discharge thatmight 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 (thesecond 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 previousdischarge and the recharge characteristic of the battery.

Thus there is goodassurance of fully recharging the battery within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, 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 stillgreater than 2.07 V and float voltage is found to be satisfactory, this is notindication of a substantially discharged battery and 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is a reasonable timeprior to declaring the battery inoperable.

Since Required Actions B.1 and C.1 only specify "perform,"

a failure of SR3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in the Required Actionnot 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.3With one required vital or DG battery with one or more cells electrolyte levelabove the top of the plates, but below the minimum established design limits, thebattery still retains sufficient capacity to perform the intended function.

Therefore, the affected battery is not required to be considered inoperable solely as a resultof electrolyte level not met. Within 31 days the minimum established designlimits for electrolyte level must be re-established.

With electrolyte level below the top of the plates there is a potential for dryoutand plate degradation.

Required Actions E.1 and E.2 addressed this potential aswell as provisions in Specification 5.7.2.21

.b, Battery Monitoring andMaintenance Program.

They are modified by a Note that indicates they are onlyapplicable if electrolyte level is below the top of the plates. Within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> level isrequired to be restored to above the top of the plates. The Required Action E.2requirement to verify that there is no leakage by visual inspection and theSpecification 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. Theyare performed following the restoration of the electrolyte level to above the top of(continued)

Watts Bar-Unit 1B 3.8-76 Battery Parameters B 3.8.6BASESACTIONS E.1, E.2, and E.3 (continued) the plates. Based on the results of the manufacturer's recommended testing thebattery may have to be declared inoperable and the affected cell(s) replaced.

F.1With one required vital or DG battery with pilot cell temperature less than theminimum established design limits, 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is allowed to restore thetemperature to within limits. A low electrolyte temperature limits the current andpower available.

Since the battery is sized with margin, while battery capacity isdegraded, sufficient capacity exists to perform the intended function and theaffected battery is not required to be considered inoperable solely as a result ofthe pilot cell temperature not met.G.. 1With more than one required vital or more than one DG batteries with batteryparameters not within limits as specified in Conditions A through F there is notsufficient assurance that battery capacity has not been affected to the degreethat the batteries can still perform their required

function, given that redundant batteries are involved.

With redundant batteries involved this potential couldresult 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 mustbe restored to within limits on at least one subsystem within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.H.1With one or more batteries with any battery parameter outside the allowances ofthe Required Actions for Condition A, B, C, D, E, F or G sufficient capacity tosupply the maximum expected load requirement is not assured and thecorresponding battery must be declared inoperable.

Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 Vand float current greater than 2 amps for the vital batteries or I amp for the DGbatteries indicates that the battery capacity may not be sufficient to perform theintended functions.

Under these conditions, the battery must be declaredinoperable immediately.

Watts Bar-Unit 1B 3.8-77 Battery Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.1 and SR 3.8.6.2REQUIREMENTS Verifying battery float current while on float charge is used to determine the stateof charge of the battery.

Float charge is the condition in which the charger issupplying the continuous charge required to overcome the internal losses of abattery and maintain the battery in a charged state. The equipment used tomonitor float current must have the necessary accuracy and resolution tomeasure electrical currents in the expected range. The float current requirements are based on the float current indicative of a charged battery.

The 7 dayFrequency is consistent with IEEE-450 (Ref. 2).This SR is modified by a Note that states the float current requirement is notrequired to be met when battery terminal voltage is less than the minimumestablished float voltage of SR 3.8.4.1 or SR 3.8.4.2.

When this float voltage isnot maintained the Required Actions of LCO 3.8.4 ACTION A or E are beingtaken, which provide the necessary and appropriate verifications of the batterycondition.

Furthermore, the float current limit of 2 amps for the vital battery and1 amp for the DG battery is established based on the nominal float voltage valueand is not directly applicable when this voltage is not maintained.

SR 3.8.6.3 and SR 3.8.6.6Optimal long term battery performance is obtained by maintaining float voltagegreater than or equal to the minimum established design limits provided by thebattery manufacturer which is 2.20 Vpc. This corresponds to-a terminal voltageof 128V for the DG batteries, 132V for the vital batteries I through IV and 136Vfor the vital battery V. The specified float voltage provides adequate over-potential, which limits the formation of lead sulfate and self discharge, whichcould eventually render the battery inoperable.

Float voltages in this range orless, but greater than 2.07 Vpc, are addressed in Specification 5.7.2.21.

SRs3.8.6.3 and 3.8.6.6 require verification that the cell float voltages are equal to orgreater than the short term absolute minimum voltage of 2.07V.The Frequency for cell voltage verification every 31 days for pilot cell and 92days for each connected cell is consistent with IEEE-450 (Ref. 2).SR 3.8.6.4The limit specified for electrolyte level ensures that the plates suffer no physicaldamage and maintains adequate electron transfer capability.

The minimumdesign electrolyte level is the minimum level indication mark on the battery celljar. The Frequency is consistent with IEEE-450 (Ref. 2).(continued)

Watts Bar-Unit 1B 3.8-78 Battery Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.5REQUIREMENTS (continued)

This Surveillance verifies that the pilot cell temperature is greater than or equal tothe minimum established design limit (i.e., 60 OF for vital batteries and 50 OF forDG batteries).

Pilot cell electrolyte temperature is maintained above thistemperature to assure the battery can provide the required current and voltage tomeet the design requirements.

Temperature lower than assumed in batterysizing calculations will not ensure battery capacity is sufficient to perform itsdesign function.

The Frequency is consistent with IEEE-450 (Ref. 2).SR 3.8.6.7A battery performance discharge test is a test of battery capacity using constantcurrent.

The test is intended to determine overall battery degradation due to ageand usage.Either the battery performance discharge test or the modified performance discharge test is acceptable for satisfying SR 3.8.6.7;

however, only the modifiedperformance discharge test may be used to satisfy the battery service testrequirements of SR 3.8.4.7.A modified performance test is a test of the battery capacity and its ability toprovide a high rate, short duration load (usually the highest rate of the dutycycle). This will often confirm the battery's ability to meet the load duty cycle, inaddition to determining its percentage of rated capacity.

Initial conditions for themodified performance discharge test should be identical to those specified for aservice test.It may consist of just two rates; for instance the one minute rate for the battery orthe largest current load of the duty cycle, followed by the test rate employed forthe 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 verysmall portion of the battery capacity, the test rate can be changed to that for theperformance test without compromising the results of the performance discharge test. The battery terminal voltage for the modified performance discharge testmust remain above the minimum battery terminal voltage specified in the batteryservice 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 bereplaced if its capacity is below 80% of the manufacturer's rating. A capacity of80% shows that the battery rate of deterioration is increasing, even if there isample capacity to meet the load requirements.

Furthermore, the battery is sizedto meet the assumed duty cycle loads when the battery design capacity reachesthis 80% limit.(continued)

Watts Bar-Unit 1B 3.8-79 Battery Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)

SR 3.8.6.7The Surveillance Frequency for this test is normally 60 months. If the batteryshows degradation, or if the battery has reached 85% of its expected life andcapacity is < 100% of the manufacturer's rating, the Surveillance Frequency isreduced to 12 months. However, if the battery shows no degradation but hasreached 85% of its expected life, the Surveillance Frequency is only reduced to24 months for batteries that retain capacity

-> 100% of the manufacturer's ratings.Degradation is indicated, according to IEEE-450 (Ref. 2), when the batterycapacity drops by more than 10% relative to its capacity on the previousperformance test or when it is > 10% below the manufacturer's rating. TheseFrequencies 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 totake credit for unplanned events that satisfy this SR. Examples of unplanned events may include:1) Unexpected operational events which cause the equipment to performthe function specified by this Surveillance for which adequatedocumentation of the required performance is available; and2) Post corrective maintenance testing that requires performance of thisSurveillance in order to restore the component to OPERABLE, providedthe maintenance was required, or performed in conjunction withmaintenance required to maintain OPERABILITY or reliability.

REFERENCES

1. Watts Bar FSAR, Section 15, "Accident Analysis,"

and Section 6,"Engineered Safety Features."

2. IEEE Std 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.3. IEEE Std 485-1983, "IEEE Recommended Practice for Sizing LargeLead Storage Batteries for Generating Stations and Substations,"

TheInstitute of Electrical and Electronics Engineers, Inc.4. Watts Bar FSAR, Section 8, "Electric Power."Watts Bar-Unit 1B 3.8-80 ATTACHMENT 5Plant Specific Verification Regarding the Use of Float Current Monitoring to VerifyBattery State of ChargeA5-1 C.DTECHNOLOGIES, INC.Power Solutions 1400 Union Meeting RoadBlue Bell, PA 19422Phone: (215) 775-1314Fax: (215) 619-7887Sent via Email to: tcwalker(ctva..ov May 30, 2013Mr. Tim WalkerWatts Bar Nuclear PlantTennessee Valley Authority

Subject:

Use of Float Current to Determine Operability Revision of Letter dated February 22, 2013

Dear Tim:

The following statements are based on a battery temperature of 77F.For the LCUN-33 batteries, when the float current drops to less than or equal to 2 amps,the battery would have been at least 98% recharged.

For the KCR-7 batteries, when the float current drops to less than or equal to 1 amp, thebattery would have been at least 98% recharged.

This relationship will not change as the batteries age.These values of float current are also valid if the float voltage has been adjusted tocompensate for battery temperatures that are above or below 77F. See C&D'sInstallation and Operating Manual (RS-1476) at the following link for recommended temperature compensation factors.http://cdtechno.com/pdf/refý/rs 1476 0610.pdfI hope that this information meets your needs. If you require any additional information, please contact me.Regards,Larry A. CarsonNuclear Product ManagerC&D Technologies, Inc.

ATTACHMENT 6120V AC & 125V DC Vital Plant Control Power System DiagramA6-1 I IL -iI L t o) -) ') )-TIMillI52I T, l 'lFL [-7*rtTh___~ ~ F_ _ -222 10 1_ _ _L4.4 ?i4 2VlF 1 F -F- -f J J-LV ; 2 1 IT 102 LWA I~ ,L J"AwII Li---sLiL ( I T( W (I t1' I I '- EI II I 9 I I .( I; II E , I I (.c[ III I ,- I I L -F-- III "= I I r III I il ~ Ii L --L 2 *all 2 2 2 22,1a~~ll f202222wo99N2222222 22222I a 4 22L( 8 RT-2(1-22

= 221UFSAR AMENDMENT 9WATTS BARFINAL SAFETYANALYSIS REPORTPOWERHOUSE UNITS 1 & 2 KEYDIAGRAM 120V AC & 125V DCVITAL PLANT CONTROL POWERSYSTEMTVA DWG NO. 1-45W700-1 R31FIGURE 8.1-3 ENCLOSURE2 List of Regulatory Commitments Upon implementation of the approved Technical Specification amendment, WVA will meet thefollowing commitments:

1. TVA will ensure that the equipment that will be used to monitor float current underSR 3.8.6.1 and SR 3.8.6.2 will have the necessary accuracy and capability to measureelectrical currents in the expected range. Additionally, TVA verifies that the minimumrequired procedural time to measure battery float current will be 30 seconds or asrecommended by the float current measurement instrument manufacturer.

Thisminimum float current measurement time is required to provide a more accurate batteryfloat current reading.2. TVA will ensure that battery room temperature is routinely monitored such that a roomtemperature excursion could reasonably expect to be detected and corrected prior to theaverage battery electrolyte temperature dropping below the minimum electrolyte temperature.

3. The cell resistance limits in existing SR 3.8.4.5 will be relocated to the Battery Monitoring and Maintenance Program.

The following cell connection resistance limits are based onbattery vendor recommendations and are listed in the table below:Connection Vital Batteries DG Batteries (pOhm) (pOhm)Inter-cell 80 80Inter-rack 50 50Inter-tier 120 50Terminal Connections 50 504. TVA will ensure that the modified performance discharge test for each DG batterycompletely encompasses the load profile of the battery service test and that itadequately confirms the intent of the service test to verify the DG battery capacity tosupply the design basis load profile.5. Monitoring of battery parameters (i.e., specific

gravity, electrolyte level, cell temperature, float voltage, connection resistance, and physical condition) will be relocated to thelicensee-controlled program as required and described in TS Section 5.7.2.21, "Programs and Manuals,"

and titled the "Battery Monitoring and Maintenance Program."

6. TVA will ensure that plant procedures will require verification of the se.lection of the pilotcell or cells when performing SR 3.8.6.5.7. TVA will revise the UFSAR to include the following, as part of the adoption of TSTF-500, Revision 2.E2-1 of 2
a. Describe how a 2 percent design margin for the batteries corresponds to a 2 ampfloat current value for the vital battery and 1 amp for the DG battery indicating that the battery is 98 percent charged.b. State how long term battery performance is obtained by maintaining a floatvoltage greater than or equal to the minimum established design limits providedby the battery manufacturer.
c. Describe how the batteries are sized with correction margins that includetemperature and aging and how these margins are maintained.
d. State the minimum established design limit for battery terminal float voltage.e. State the minimum established design limit for electrolyte level.f. State the minimum established design limit for electrolyte temperature.
g. Describe how each battery is designed with additional capacity above thatrequired by the design duty cycles to allow for temperature variations and otherfactors.h. Describe normal DC system operation i.e., powered from the battery chargerswith the batteries floating on the system, and with a loss of normal power to thebattery charger.Comply with RG 1.129 Revision 2, Maintenance,
Testing, and Replacement ofVented Lead-Acid Storage Batteries for Nuclear Power Plants which endorsesIEEE 450-2002.

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