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{{#Wiki_filter:RCS Specific ActivityB 3.4.16BASES (continued)
APPLICABLE SAFETYANALYSESThe LCO limits on the specific activity of the reactor coolant ensures thatthe resulting 2 hour doses at the site boundary and Main Control Roomaccident doses will not exceed the appropriate 10 CFR 100 doseguideline limits and 10 CFR 50, Appendix A, GDC 19 dose guideline limits following a SGTR or MSLB accident.
The SGTR and MSLB safetyanalysis (Ref. 2) assumes the specific activity of the reactor coolant at theLCO limit and an existing reactor coolant steam generator (SG) tubeleakage rate of 150 gallons per day (GPD). The safety analysis assumesthe specific activity of the secondary coolant at its limit of 0.1 1iCi/gmDOSE EQUIVALENT 1-131 from LCO 3.7.14, "Secondary SpecificActivity."
The analysis for the SGTR and MSLB accidents establish the acceptance limits for RCS specific activity.
Reference to these analyses is used toassess changes to the unit that could affect RCS specific
: activity, as theyrelate to the acceptance limits.The analyses are for two cases of reactor coolant specific activity.
Onecase assumes specific activity at 0.265 PCi/gm DOSE EQUIVALENT 1-131 with an iodine spike immediately after the accident that increases the iodine activity in the reactor coolant by a factor of 500 times the iodineproduction rate necessary to maintain a steady state iodine concentration of 0.265 jiCi/gm DOSE EQUIVALENT 1-131. The second case assumesthe initial reactor coolant iodine activity at 2-1-14 pICi/gm DOSEEQUIVALENT 1-131 due to a pre-accident iodine spike caused by anRCS transient.
In both cases, the noble gas activity in the reactor coolantequals the LCO limit of 100/E tpCi/gm for gross specific activity.
The analysis also assumes a loss of offsite power at the same time as theSGTR and MSLB event. The SGTR causes a reduction in reactor coolantinventory.
The reduction initiates a reactor trip from a low pressurizer pressure signal or an RCS overtemperature AT signal. The MSLB resultsin a reactor trip due to low steam pressure.
The coincident loss of offsite power causes the steam dump valves toclose to protect the condenser.
The rise in pressure in the ruptured SGdischarges radioactively contaminated steam to the atmosphere throughthe SG power operated relief valves and the main steam safety valves.The unaffected SGs remove core decay heat by venting steam to theatmosphere until the cooldown ends.(continued)
IWatts Bar -Unit 2(developmental)
B 3.4-84BHI RCS Specific ActivityB 3.4.16BASESAPPLICABLE SAFETYANALYSES(continued)
The safety analysis shows the radiological consequences of an SGTRand MSLB accident are within the appropriate 10 CFR 100 and10 CFR 50, Appendix A, GDC 19 dose guideline limits. Operation withiodine specific activity levels greater than the LCO limit is permissible, ifthe activity levels do not exceed 241-14 ýtCi/gm DOSE EQUIVALENT 1-131, in the applicable specification, for more than 48 hours. The safetyanalysis has concurrent and pre-accident iodine spiking levels up to24-14 piCi/gm DOSE EQUIVALENT 1-131.The limits on RCS specific activity are also used for establishing standardization in radiation shielding and plant personnel radiation protection practices.
RCS specific activity satisfies Criterion 2 of the NRC Policy Statement.
ILCOThe specific iodine activity is limited to 0.265 tiCi/gm DOSEEQUIVALENT 1-131, and the gross specific activity in the reactor coolantis limited to the number of piCi/gm equal to 100 divided by E (averagedisintegration energy of the sum of the average beta and gammaenergies of the coolant nuclides).
The limit on DOSE EQUIVALENT 1-131ensures the 2 hour thyroid dose to an individual at the site boundary andaccident dose to personnel in the Main Control Room during the DesignBasis Accident (DBA) will be within the allowed thyroid dose. The limit ongross specific activity ensures the 2 hour whole body dose to anindividual at the site boundary and accident dose to personnel in the MainControl Room during the DBA will be within the allowed whole body dose.The SGTR and MSLB accident analysis (Ref. 2) shows that the 2 hoursite boundary dose levels and Main Control Room accident dose arewithin acceptable limits. Violation of the LCO may result in reactorcoolant radioactivity levels that could, in the event of a SGTR or MSLB,lead to site boundary doses that exceed the 10 CFR 100 dose guideline limits, or Main Control Room accident dose that exceed the 10 CFR 50,Appendix A, GDC 19 dose limits.(continued)
Watts Bar -Unit 2(developmental)
B 3.4-85A RCS Specific ActivityB 3.4.16BASES (continued)
APPLICABILITY In MODES 1 and 2, and in MODE 3 with RCS average temperature
_> 5000F, operation within the LCO limits for DOSE EQUIVALENT 1-131and gross specific activity are necessary to contain the potential consequences of an accident to within the acceptable Main Control Roomand site boundary dose values.For operation in MODE 3 with RCS average temperature
< 5000F, and inMODES 4 and 5, the release of radioactivity in the event of a SGTR isunlikely since the saturation pressure of the reactor coolant is below thelift pressure settings of the main steam safety valves.ACTIONSA.1 and A.2With the DOSE EQUIVALENT 1-131 greater than the LCO limit, samplesat intervals of 4 hours must be taken to demonstrate that the limit of24-14 gCi/gm is not exceeded.
The Completion Time of 4 hours isrequired to obtain and analyze a sample. Sampling is done to continue toprovide a trend.The DOSE EQUIVALENT 1-131 must be restored to within limits within48 hours. The Completion Time of 48 hours is required, if the limitviolation resulted from normal iodine spiking.A Note permits the use of the provisions of LCO 3.0.4.c.
This allowance permits entry into the applicable MODE(S) while relying on the ACTIONS.This allowance is acceptable due to the significant conservatism incorporated into the specific activity limit, the low probability of an eventwhich is limiting due to exceeding this limit, and the ability to restoretransient specific activity excursions while the plant remains at, orproceeds to power operation.
I(continued)
Watts Bar -Unit 2(developmental)
B 3.4-86AH I RCS Specific ActivityB 3.4.16BASESACTIONS B.1 and B.2(continued)
With the gross specific activity in excess of the allowed limit, an analysismust be performed within 4 hours to determine DOSE EQUIVALENT 1-131. The Completion Time of 4 hours is required to obtain and analyzea sample.The change within 6 hours to MODE 3 and RCS average temperature
< 500OF lowers the saturation pressure of the reactor coolant below thesetpoints of the main steam safety valves and prevents venting the SG tothe environment in an SGTR event. The allowed Completion Time of6 hours is reasonable, based on operating experience, to reach MODE 3below 500OF from full power conditions in an orderly manner and withoutchallenging plant systems.C.1If a Required Action and the associated Completion Time of Condition Ais not met or if the DOSE EQUIVALENT 1-131 is greater than 24-14 pCi/gm, the reactor must be brought to MODE 3 with RCS averagetemperature
< 500OF within 6 hours. The Completion Time of 6 hours isreasonable, based on operating experience, to reach MODE 3 below500OF from full power conditions in an orderly manner and withoutchallenging plant systems.SURVEILLANCE SR 3.4.16.1REQUIREMENTS SR 3.4.16.1 requires performing a gamma isotopic analysis as a measureof the gross specific activity of the reactor coolant at least once every7 days. While basically a quantitative measure of radionuclides with halflives longer than 15 minutes, excluding
: iodines, this measurement is thesum of the degassed gamma activities and the gaseous gamma activities in the sample taken. This Surveillance provides an indication of anyincrease in gross specific activity.
Trending the results of this Surveillance allows proper remedial action tobe taken before reaching the LCO limit under normal operating conditions.
The Surveillance is applicable in MODES 1 and 2, and inMODE 3 with Tavg at least 5000F. The 7-day Frequency considers theunlikelihood of a gross fuel failure during the time.(continued)
Watts Bar -Unit 2 B 3.4-87(developmental)
AHI Containment B 3.6.1BASESAPPLICABLE Satisfactory leakage rate test results are a requirement for theSAFETY establishment of containment OPERABILITY.
ANALYSES(continued)
The containment satisfies Criterion 3 of the NRC Policy Statement.
LCO Containment OPERABILITY is maintained by limiting leakage to < 1.0 La,except prior to the first start up after performing a required Containment Leakage Rate Testing Program leakage test. At this time, applicable leakage limits must be met.Compliance with this LCO will ensure a containment configuration, including equipment
: hatches, that is structurally sound and that will limitleakage to those leakage rates assumed in the safety analysis.
Individual leakage rates specified for the containment air lock(LCO 3.6.2), purge valves with resilient seals, and Shield Buildingcontainment bypass leakage (LCO 3.6.3) are not specifically part of theacceptance criteria of 10 CFR 50, Appendix J, Option B. Therefore, leakage rates exceeding these individual limits only result in thecontainment being inoperable when the leakage results in exceeding theacceptance criteria of Appendix J, Option B.APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material into containment.
In MODES 5 and 6, the probability andconsequences of these events are reduced due to the pressure andtemperature limitations of these MODES. Therefore, containment is notrequired to be OPERABLE in MODES 5 and 6 to prevent leakage ofradioactive material from containment.
The requiremonts for cont4a!nmnt during MODE= 6 are addroso;-d-
'A LCO- 3.9.41, Contann ontrationu (continued)
Watts Bar -Unit 2(developmental)
B 3.6-3AH Containment Air LocksB 3.6.2BASES (continued)
APPLICABLE SAFETYANALYSESThe DBAs that result in a significant release of radioactive material withincontainment are a loss of coolant accident and a rod ejection accident(Ref. 2). In the analysis of each of these accidents, it is assumed thatcontainment is OPERABLE such that release of fission products to theenvironment is controlled by the rate of containment leakage.
Thecontainment was designed with an allowable leakage rate (La) of 0.25%of containment air weight per day (Ref. 2), at the calculated peakcontainment pressure of 15.0 psig. This allowable leakage rate forms thebasis for the acceptance criteria imposed on the SRs associated with theair locks.The containment air locks satisfy Criterion 3 of the NRC PolicyStatement.
LCOEach containment air lock forms part of the containment pressureboundary.
As part of containment pressure
: boundary, the air lock safetyfunction is related to control of the containment leakage rate resulting from a DBA. Thus, each air lock's structural integrity and leak tightness are essential to the successful mitigation of such an event.Each air lock is required to be OPERABLE.
For the air lock to beconsidered
: OPERABLE, the air lock interlock mechanism must beOPERABLE, the air lock must be in compliance with the Type B air lockleakage test, and both air lock doors must be OPERABLE.
The interlock allows only one air lock door of an air lock to be opened at one time. Thisprovision ensures that a gross breach of containment does not exist whencontainment is required to be OPERABLE.
Closure of a single door ineach air lock is sufficient to provide a leak tight barrier following postulated events. Nevertheless, both doors are kept closed when the airlock is not being used for normal entry into and exit from containment.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment.
In MODES 5 and 6, the probability andconsequences of these events are reduced due to the pressure andtemperature limitations of these MODES. Therefore, the containment airlocks are not required in MODES 5 and 6 to prevent leakage ofradioactive material from containment.
The roquiromnts for the air locks .iunq MGOFDE 6 aro addr ,sed in 3.0.1,"Containment PenetrRtW0ns."
(continued)
Watts Bar -Unit 2(developmental)
B 3.6-7AH Containment Isolation ValvesB 3.6.3BASES (continued)
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment.
In MODES 5 and 6, the probability andconsequences of these events are reduced due to the pressure andtemperature limitations of these MODES. Therefore, the containment isolation valves are not required to be OPERABLE in MODES 5 and 6.-The requireme~nts for contaiAnment isolation valVe6 during MODE 6 areaddrocod in LCOQ 3.9.4, Ponotration,"
ACTIONS The ACTIONS are modified by a Note allowing penetration flow paths, tobe unisolated intermittently under administrative controls.
Theseadministrative controls consist of stationing a dedicated operator(licensed or unlicensed) at the valve controls, who is in continuous communication with the control room. In this way, the penetration can berapidly isolated when a need for containment isolation is indicated.
Forvalve controls located in the control room, an operator (other than theShift Operations Supervisor (SOS), ASOS, or the Operator at theControls) may monitor containment isolation signal status rather than bestationed at the valve controls.
Other secondary responsibilities which donot prevent adequate monitoring of containment isolation signal statusmay be performed by the operator provided his/her primary responsibility is rapid isolation of the penetration when needed for containment isolation.
Use of the Unit Control Room Operator (CRO) to perform thisfunction should be limited to those situations where no other operator isavailable.
A second Note has been added to provide clarification that, for this LCO,separate Condition entry is allowed for each penetration flow path. Thisis acceptable, since the Required Actions for each Condition provideappropriate compensatory actions for each inoperable containment isolation valve. Complying with the Required Actions may allow forcontinued operation, and subsequent inoperable containment isolation valves are governed by subsequent Condition entry and application ofassociated Required Actions.The ACTIONS are further modified by third Note, which ensuresappropriate remedial actions are taken, if necessary, if the affectedsystems are rendered inoperable by an inoperable containment isolation valve.In the event the isolation valve leakage results in exceeding the overallcontainment leakage rate, Note 4 directs entry into the applicable Conditions and Required Actions of LCO 3.6.1.(continued)
Watts Bar -Unit 2 B 3.6-16(developmental)
AH HMSB 3.6.8BASESBACKGROUND (continued)
When the HMS is initiated, the ignitor elements are energized and heatup to a surface temperature
_ 1700'F. At this temperature, they ignite thehydrogen gas that is present in the airspace in the vicinity of the ignitor.The HMS depends on the dispersed location of the ignitors so that localpockets of hydrogen at increased concentrations would burn beforereaching a hydrogen concentration significantly higher than the lowerflammability limit. Hydrogen ignition in the vicinity of the ignitors isassumed to occur when the local hydrogen concentration reaches aminimum 5.0 volume percent (v/o).APPLICABLE SAFETYANALYSESThe HMS causes hydrogen in containment to burn in a controlled manneras it accumulates following a degraded core accident (Ref. 3). Burningoccurs at the lower flammability concentration, where the resulting temperatures and pressures are relatively benign. Without the system,hydrogen could build up to higher concentrations that could result in aviolent reaction if ignited by a random ignition source after such a buildup.The hydrogen ignitors are not included for mitigation of a Design BasisAccident (DBA) because an amount of hydrogen equivalent to thatgenerated from the reaction of 75% of the fuel cladding with water is far inexcess of the hydrogen calculated for the limiting DBA loss of coolantaccident (LOCA). The hydrgon .onc..-entr.ation ro..ulting from a DBA cAnbeA M.Atainta-nd 18-66 thRAn the- flamFmab9ility "imit ucin*g the hydrogerocombinorc.
The hydrogen ignitors.,hewe.'e-',
have been shown byprobabilistic risk analysis to be a significant contributor to limiting theseverity of accident sequences that are commonly found to dominate riskfor plants with ice condenser containments.
As such, the hydrogenignitors are considered to be risk significant in accordance with the NRCPolicy Statement.
(continued)
Watts Bar -Unit 2(developmental)
B 3.6-43AH Divider Barrier Integrity B 3.6.13BASESSURVEILLANCE REQUIREMENTS (continued)
SR 3.6.13.3Verification, by visual inspection, after each opening of a personnel access door or equipment hatch that it has been closed makes theoperator aware of the importance of closing it and thereby providesadditional assurance that divider barrier integrity is maintained while inapplicable MODES.SR 3.6.13.4Not used.The di-ider barrior o6al can be field 6pliced for ropa!r purposesutilizing a cold bond procedure rather than the original field Gplice-technique of vulcanization.
: However, the cod bond adhesive, whichworks in conjunc~tion with a bolt array to splice the field joint, cOulId not beheat aged te 40 years plaRt life pFr6r to ac,-ptability testing.
expesure te the elevaotehd tempeFatutres required foF heat aging the sA'emateria-l w.as destructive to the adhesive.
The seal mnaterial war, heataged to 40 years equivalent ago, and the entire joint assembly war,irFradi~ated-to- 10 year nrmFRal operation plus accident integrated doese-,Conducting periodic peel tests On the test specimensR provides assuranca that the ad-hesive has net degraded in the containmen-.t environmAFent.
Thejjoint ,followed dby y1 8month sfthe pepeo llength his sgreate rtha n14' "and36 6month si fthe Pepee llengthi sless tha nor requal lt o12" ir sbased duponthe eorigina lvendor's srecommendatio nwhichi s6base dupo nbaselineexAa minaRtio1 no fthe estre ngth o fthe eadhesive.
Therefore
,the eF requ encywa: -scon c ud e dtn ob enAsco t abI of rom a; r eAliahdbili t y tndnn int.vSR 3.6.13.5Visual inspection of the seal around the perimeter provides assurance that the seal is properly secured in place. The Frequency of 18 monthswas developed considering such factors as the inaccessibility of the sealsand absence of traffic in their vicinity, the strength of the bolts andmechanisms used to secure the seal, and the plant conditions needed toperform the SR. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 monthFrequency.
Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
REFERENCES 1 .Wafts Bar FSAR, Section 6.2, "Containment Systems."
Watts Bar -Unit 2(developmental)
B 3.6-83AH CCSB 3.7.7B 3.7 PLANT SYSTEMSB 3.7.7 Component Cooling System (CCS)BASESBACKGROUND The CCS provides a heat sink for the removal of process and operating heat from safety related components during a Design Basis Accident(DBA) or transient.
During normal operation, the CCS also provides thisfunction for various non-essential components, as well as the spent fuelstorage pool. The CCS serves as a barrier to the release of radioactive byproducts between potentially radioactive systems and the Essential Raw Cooling Water (ERCW) System, and thus to the environment.
The CCS is arranged as two independent, full-capacity cooling trains,Train A and Train B. Train A in Unit 2 is served by CCS Hx B andCCS pump 2A-A. Pump 2B-B, which is actually Train B equipment, isalso normally aligned to the Train A header in Unit 2. However,pump 2B-B can be realigned to Train B on loss of Train A.Train B is served by CCS Hx C. Normally, only CCS pump C-S is alignedto the Train B header since few non-essential, normally-operating loadsare assigned to Train B. However, pump 2B-B can be realigned to theTrain B header on a loss of the C-S pump.Each safety related train is powered from a separate bus. An open surgetank in the system provides pump trip protective functions to ensure thatsufficient net positive suction head is available.
The pump in each train isautomatically started on receipt of a safety injection signal, and allnon-essential components will be manually isolated.
CCS Pump 1B-B may be substituted for CCS Pump C-S supplying the Unit 2 CCS Train B header provided the OPERABILITY requirements are met.Additional information on the design and operation of the system, alongwith a list of the components served, is presented in the FSAR,Section 9.2.2 (Ref. 1). The principal safety related function of the CCS isthe removal of decay heat from the reactor via the Residual HeatRemoval (RHR) System. This may be during a normal or post accidentcooldown and shutdown.
(continued)
Watts Bar -Unit 2 B 3.7-36(developmental)
GHI CCSB 3.7.7BASESLCO(continued)
: c. If CCS Pump 11B-B is substituted for CCS Pump C-S supplying the Unit 2 CCS Train B header, CCS Pump IB-B is onlyconsidered OPERABLE when aligned to the CCS Train B headerand operating.
The isolation of CCS from other components or systems not required forsafety may render those components or systems inoperable but does notaffect the OPERABILITY of the CCS.CCS Pump 1B-B only receives a safety injection (SI) signal fromUnit 1. If CCS Pump I B-B is in a standby mode and is aligned as asubstitute for CCS Pump C-S, then Unit 2 CCS train B will not beoperable.
Conversely, if CCS Pump 1B-B is operating and alignedas a substitute for CCS Pump C-S supplying the CCS Train Bheader, then Unit 2 CCS Train B is OPERABLE.
The presence of anSI signal in Unit 2 will have no effect on CCS Pump 1B-B and thepump will continue to operate.
In the event of a loss of offsitepower, with or without an SI signal present, CCS Pump I B-B will beautomatically sequenced onto its respective diesel and continue toperform its required safety function.
APPLICABILITY In MODES 1, 2, 3, and 4, the CCS is a normally operating system, whichmust be prepared to perform its post accident safety functions, primarily RCS heat removal, which is achieved by cooling the RHR heatexchanger.
In MODE 5 or 6, the OPERABILITY requirements of the CCS aredetermined by the systems it supports.
(continued)
Watts Bar -Unit 2(developmental)
B 3.7-38AH I CCSB 3.7.7BASESSURVEILLANCE REQUIREMENTS (continued)
S R 3.7.7.4This SR verifies proper automatic operation of the CCS pumps on anactual or simulated actuation signal. The CCS is a normally operating system that cannot be fully actuated as part of routine testing duringnormal operation.
The 18 month Frequency is based on the need toperform this Surveillance under the conditions that apply during a unitoutage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience hasshown that these components usually pass the Surveillance whenperformed at the 18 month Frequency.
Therefore, the Frequency isacceptable from a reliability standpoint.
This SR does not apply to CCS Pump 1B-B when substituted forCCS Pump C-S to establish operability of Unit 2 CCS Train B. CCSPump 1B-B does not receive an SI actuation signal from Unit 2. If itis operating and aligned as a substitute for CCS Pump C-Ssupplying the CCS Train B header, the presence of an SI signal inUnit 2 will have no effect on CCS Pump 1B-B and the pump willcontinue to perform its required safety function.
In the event of aloss of offsite power, with or without an SI signal present, CCSPump 1B-B will be automatically sequenced onto its respective diesel and continue to perform its required safety function.
SR 3.7.7.5This SR assures the operability of Unit 2 CCS Train B when CCSPump I B-B is substituted for CCS Pump C-S. Since CCS Pump I B-Bdoes not receive an Sl actuation signal from Unit 2, by verifying thepump is aligned and operating, assurance is provided that Unit 2CCS Train B will be operable in the event of a Unit 2 SI actuation.
REFERENCES
: 1. Watts Bar FSAR, Section 9.2.2, "Component Cooling System."2. Watts Bar Component Cooling System Description, N3-70-4002.
Watts Bar -Unit 2(developmental)
B 3.741AH I ABGTSB 3.7.12B 3.7 PLANT SYSTEMSB 3.7.12 Auxiliary Building Gas Treatment System (ABGTS)BASESBACKGROUND The ABGTS filters airborne radioactive particulates from the area of thefuel following a fuel handling aRd from the area of activeUnit 2 ECCS components and Unit 2 penetration rooms following a lossof coolant accident (LOCA).The ABGTS consists of two independent and redundant trains. Eachtrain consists of a heater, a prefilter, moisture separator, a high efficiency particulate air (HEPA) filter, two activated charcoal adsorber sections forremoval of gaseous activity (principally iodines),
and a fan. Ductwork, valves or dampers, and instrumentation also form part of the system.A second bank of HEPA filters follows the adsorber section to collectcarbon fines and provide backup in case the main HEPA filter bank fails.The downstream HEPA filter is not credited in the analysis.
The systeminitiates filtered ventilation of the Auxiliary Building Secondary Containment Enclosure (ABSCE) exhaust air following receipt of aPhase A containment isolation signal or a high radiatienR Gigal from, thespent fuel pool area.The ABGTS is a standby system, not used during normal plantoperations.
During emergency operations, the ABSCE dampers arerealigned and ABGTS fans are started to begin filtration.
Air is exhausted from the Unit 2 ECCS pump rooms, Unit 2 penetration rooms, and fuelhandling area through the filter trains. The prefilters or moistureseparators remove any large particles in the air, and any entrained waterdroplets
: present, to prevent excessive loading of the HEPA filters andcharcoal adsorbers.
The plant design basis requirFeS that when movinRg irradiated fuel in theAuxiliar; Building and/or Containment With the Containment open to theAui~~ Buildingq A:39GE SpG a signal fQAthe Gpem fW8uu90radi-ation moritorm 0 RE 90 102 and 103 Will initiate a C-otainment Ventilatior n Isolation (VI) in addition to their rnormnl funcrtin.
In addition, a 6ignal froEm the cnAtaiFnment purge radc-iafionmnior I RE 90 130 and131 or othr VI signal " 11 initiate that po.tion of the ABI normal*lnitiated by the spent fuel poo0 radiation monitors..
Additionally, aContah."inmentIolation Phase A (SI -igRal) from the operatiRg unit, hightemper~ature in the Auxiliary Building air intakes, or manual AB!(continued)
Watts Bar -Unit 2(developmental)
B 3.7-63GH ABGTSB 3.7.12BASESBACKGROUND (continued)
.:viw cas a ivi w anaui inl inl meu cas vwnre incvB J tl wAt Jl.J~ fl11 7Ifl~ TV U~~fl T~rTYfl~
TtJ ~~tJT I flJ fl T~ I ~LIflflILfl 3 ~IAIThAII
~ -Vin nerie nit will initiitn CVI in the ether ,-nit ineorder to maintain thoeevvinrumentato mAut remnain operable when moeving i~rradiated fuel in theA uxiliar" Building if the containment air locGks,penetrations, equipment hatch, etc. arc open to the Auxiliary Buildin~g BSCE9 spacaes.
In addlitio, the ABGTS mu-st remain operable if thesecOntainment penotratipoc arc eoon to the Auxiliary Building durina-vnt # -n n f ;-,,4;-+
.f..r 1 ;n ; 14;A +n~ ;, +~n--" J ........
0 ......V'rar"Orl 01 01- -0 r1a a t7wrl cz rimorl .The ABGTS is discussed in the FSAR, Sections 6.5.1, 9.4.2, 15.0, and6.2.3 (Refs. 1, 2, 3, and 4, respectively).
APPLICABLE SAFETYANALYSESThe ABGTS design basis is established by the consequences of thelimiting Design Basis Accident (DBA), which is a LOCA. fue[Iamdllf&sect;
.,n,.,,4nn TI', aa nl'16*6c
-S thA .,Ihn-h 'A'n~rnn Nintan =GanQ#CiVRI II IThe analysis of the LOCA assumes that radioactive materials leaked fromthe Emergency Core Cooling System (ECCS) are filtered and adsorbedby the ABGTS. The DBA analysis of the fuel handling accident assumesthat only one train of the ABGTS is functional due to a single failure thatdisables the other train. The accident analysis accounts for the reduction in airborne radioactive material provided by the one remaining train of thisfiltration system. The amount of fission products available for releasefrom the ABSCE is determined for a fue! handfIng accident and for aLOCA. The assumption.. ... 4 ad .analySiS forF a4 fu-el handli-ng accidentfelloW the guidance proVided in Regulatory Guide 1.25 (Ref. 5) andNUREG/CR 5009 (Ref. 10). The assumptions and analysis for a LOCAfollow the guidance provided in Regulatory Guide 1.4 (Ref. 65).The ABGTS satisfies Criterion 3 of the NRC Policy Statement.
tiDIBuilding withl containmen~t air locks Or penetrations open to theo Auxiliary Building ABSCE spaceS, Or when moving fuel in the Auxiliary Buildingw:ith the con~tainment equipm~ent hatch open, the proVisions to9ntit aC-VI from. the rpent fulpelrdation monRitors and to initiate ain A.-Iki.u., Me Pertien 9+ an :Aoi normally Munatee Sy fme 6ponmi+U9!peefi r-adiation moenitors6) from a CVI, including a CVI initiated by thecontainment purge monitors, in the event of a fue! handling accident(FH1A) must be in place and functeionig.
Additionally, a Containment Isolation Phase A (SI Sign~a!)
from the oer~eat*R1 unit, higlh(continued)
Watts Bar -Unit 2(developmental)
B 3.7-64GH ABGTSB 3.7.12BASESAPPLICABLE SAFETYANALYSES(continued) temnperature lin the- Aux;Ilinay Building air intake,,
Or manual ABI Will causoa CVI 6igna! in tho refueling unit. The centainmonRt equipment hatchcannoet be open When moGVing irradiated fuel inside containmen~t inaccordance with Specifcatieon 3.9.4.The ABGT-S i6 required to be opeFable during movement of irradiated fuelin the Auxiliay Buwilding during any and during moveent ofRiRradiated fuel in ReRa;ctor Builing when the RAciltor Building isestablirhed as pan t of the ABSCE boundary (seo T-S 3.3.8, 3.7.12, &3.0.4). When ming"irra*dated fuel inside containment, at least one trainof the onmtaimetpug system mnust be operating Or the containmenAt mAust be isolated. l moeving irradiated fuel in the Auxiliary Buildingdu&#xfd;,ng timne wheRn the is olpen to the Auxiliary BuildirgABSGE6pa~6containment PU~ a eoperated, btoperatieRon hsystemR 06 not required.
: However, whether.
the containmenRt purge systemAis6 operated o-r- not in this; confguration, all containmenRt Ventilatiniolato valves and associated isrmnaonmust remnain operable.
Tirequirement is cesr to ensure a CVI can be accomAplished "FRo thespent fuel peel ra-d-;ia~tion moni-R..to-rs-in. the event of a F-H.A in the Auxiliary Building.
Additionally, a Containment Isolation Phase A (SI signal) framthe operating unit, high temnperature in the Auxiliar-y B3uilding air intakes,Or mnanual ABI 4.0ll cause a CVI cigna! in the refueling unit. In the casewhere the containment of both units is open to the Auxiliary BuldingF~
spaces, a CVI in one unit will initiate a CVI in the ether unit in order tomaintain these spaces open to the ABSCE.LCOTwo independent and redundant trains of the ABGTS are required to beOPERABLE to ensure that at least one train is available, assuming asingle failure that disables the other train, coincident with a loss of offsitepower. Total system failure could result in the atmospheric release fromthe ABSCE exceeding the 10 CFR 100 (Ref. 7-6) limits in the event of afuel handling accident or LOCA.The ABGTS is considered OPERABLE when the individual components necessary to control exposure in the fiel haii'ii-bAuxiliary Building areOPERABLE in both trains. An ABGTS train is considered OPERABLEwhen its associated:
: a. Fan is OPERABLE;
: b. HEPA filter and charcoal adsorber are not excessively restricting flow, and are capable of performing their filtration function; and(continued)
Watts Bar -Unit 2(developmental)
B 3.7-65GH ABGTSB 3.7.12BASESLCO(continued)
: c. Heater, moisture separator,
: ductwork, valves, and dampers areOPERABLE, and air circulation can be maintained.
APPLICABILITY In MODE 1, 2, 3, or 4, the ABGTS is required to be OPERABLE toprovide fission product removal associated with ECCS leaks due to aLOCA and leakage from containment and annulus.In MODE 5 or 6, the ABGTS is not required to be OPERABLE since theECCS is not required to be OPERABLE.
During mo'-ement of irradiatod fudel in the fue! handling area, the ABGTS8 is roquirod to be QPE=RARLP toalleviate the cOnceqIUoncoc of a fuel handling accident.
See additienal d*iGc3uccF~oQ in tho Backoron-d
;;nd Aen'*Rable Safot': AnaIV6ic GoctioncACTIONSA._1With one ABGTS train inoperable, action must be taken to restoreOPERABLE status within 7 days. During this period, the remaining OPERABLE train is adequate to perform the ABGTS function.
The 7-dayCompletion Time is based on the risk from an event occurring requiring the inoperable ABGTS train, and the remaining ABGTS train providing therequired protection.
B.1 and B.2IR MODE 1, 2, 3, or 1, wWhen Required Action A.1 cannot be completed within the associated Completion Time, or when both ABGTS trains areinoperable, the plant must be placed in a MODE in which the LCO doesnot apply. To achieve this status, the plant must be placed in MODE 3within 6 hours, and in MODE 5 within 36 hours. The Completion Timesare reasonable, based on operating experience, to reach the requiredplant conditions from full power conditions in an orderly manner andwithout challenging plant systems.(continued)
Watts Bar -Unit 2(developmental)
B 3.7-66AH ABGTSB 3.7.12BASESAGTQNS(Ge~tRued)
%AA, 0 ; A A *. A 4 + k I + A ;+k; +k ; 14a" atla rv tPri .UmMi" 0 wcrmp CP w r_1 W ruga r%7GGFAPI8ti9R T4AB, GIWOR9 FRevement of iFFadiated fuel ;;rsAmhI;A OR thefUel haRdIiR9 aFea, the OPPRARI F= AI3GT_9 tFaiR must be staFtimmediately ear fuel rneyeMeAt 6UspeRded.
This aGtiGA eA661F86 that theFeFna6A4A@
tr-ROR is GO PERABLE, that Re URElete6ted faWUFe6 PFeYeAtiR@
ation %kill eAr_,UF, aRd that aRy acAiye fail mw*ll he re dilyif the system is not plaGed iR epeFatien, thir, aGtiG 6PeF16i9R 9ffUel FnGY8Fn6At, WhiGh pFeGludes a fue-I an-roid-ent.
T4;' FeGludethe FneyemeRt ef fuel assemblies te a 6afe P96iti9R.
9.4VVh8R tWO tFaiRG of the ABGT-S aFe 'RepeFable du Rk4_* Ffad*ated fuel assemblies in the fuel handliRg aFea-, &#xfd;ansfieen immust be takeRte E)Iaee the URit iR a GgRditiw; iR WhiGh the I=GG de96 not apply. A.0ionAm I I I I Emarsembfies
*R the fuel na Thrs does A9t PF9Glude tFR9Y9FneAt 9f A-19-1 t9 a GialeSURVEILLANCE REQUIREMENTS SR 3.7.12.1.
Standby systems should be checked periodically to ensure that theyfunction properly.
As the environmental and normal operating conditions on this system are not severe, testing each train once every monthprovides an adequate check on this system.Monthly heater operation dries out any moisture accumulated in thecharcoal from humidity in the ambient air. The system must be operatedfor &#xfd;! 10 continuous hours with the heaters energized.
The 31 -dayFrequency is based on the known reliability of the equipment and thetwo train redundancy available.
(continued)
Wafts Bar -Unit 2(developmental)
B 3.7-67AH ABGTSB 3.7.12BASESSURVEILLANCE REQUIREMENTS (continued)
SR 3.7.12.2This SR verifies that the required ABGTS testing is performed inaccordance with the Ventilation Filter Testing Program (VFTP). TheABGTS filter tests are in accordance with Regulatory Guide 1.52 (Ref. 8).The VFTP includes testing HEPA filter performance, charcoal adsorberefficiency, minimum system flow rate, and the physical properties of theactivated charcoal (general use and following specific operations).
Specific test frequencies and additional information are discussed indetail in the VFTP.SR 3.7.12.3This SR verifies that each ABGTS train starts and operates on an actualor simulated actuation signal. The 18-month Frequency is consistent withReference 87.SR 3.7.12.4This SR verifies the integrity of the ABSCE. The ability of the ABSCE tomaintain negative pressure with respect to potentially uncontaminated adjacent areas is periodically tested to verify proper function of theABGTS. During the post accident mode of operation, the ABGTS isdesigned to maintain a slight negative pressure in the ABSCE, to preventunfiltered LEAKAGE.
The ABGTS is designed to maintain a negativepressure between -0.25 inches water gauge and -0.5 inches water gauge(value does not account for instrument error) with respect to atmospheric pressure at a nominal flow rate > 9300 cfm and < 9900 cfm. TheFrequency of 18 months is consistent with the guidance provided inNUREG-0800, Section 6.5.1 (Ref. 98).An 18-month Frequency (on a STAGGERED TEST BASIS) is consistent with Reference 87.REFERENCES
: 1. Watts Bar FSAR, Section 6.5.1, "Engineered Safety Feature (ESF)Filter Systems."
: 2. Watts Bar FSAR, Section 9.4.2, "Fuel Handling Area Ventilation System."3. Watts Bar FSAR, Section 15.0, "Accident Analysis."
(continued)
Watts Bar -Unit 2(developmental)
B 3.7-68SH ABGTSB 3.7.12BASESREFERENCES (continued)
: 4. Watts Bar FSAR, Section 6.2.3, "Secondary Containment Functional Design."5-, Rogulatory Guido 1.25, Mach 197-2, "A ,.umptien Uso-,d forFiyalwatkng tho Potentilal Radielogical Consoquoncoc of a FuolNAMOilnn
-- M WRR, uIAZoA 40a;ter 14AtRAc.65. Regulatory Guide 1.4, "Assumptions Used for Evaluating thePotential Radiological Consequences of a Loss of Coolant Accidentfor Pressurized Water Reactors."
-76. Title 10, Code of Federal Regulations, Part 100.11, "Determination of Exclusion Area, Low Population Zone, and Population CenterDistance."
: 87. Regulatory Guide 1.52 (Rev. 2), "Design, Testing and Maintenance Criteria for Post Accident Engineered-Safety-Feature Atmospheric Cleanup System Air Filtration and Adsorption Units of Light-Water Cooled Nuclear Power Plants."98. NUREG-0800, Section 6.5.1, "Standard Review Plan," Rev. 2, "ESFAtmosphere Cleanup System,"
July 1981.I4-0-F dm I i B PNUL-IGt.G Water, -c'-e MoAn ottri, U.o S? NLear neg lIuAnupFuel in Liaht W~ator PoW8r Reactors."
UJ. S. Nuclear ReaulatoR' 60mmiSc9ion.
1-orur':mm.
Watts Bar -Unit 2(developmental)
B 3.7-69BH Fuel Storage Pool Water LevelB 3.7.13B 3.7 PLANT SYSTEMSB 3.7.13 Fuel Storage Pool Water LevelBASESBACKGROUND The minimum water level in the fuel storage pool meets the assumptions of iodine decontamination factors following a fuel handling accident.
Thespecified water level shields and minimizes the general area dose whenthe storage racks are filled to their maximum capacity.
The water alsoprovides shielding during the movement of spent fuel.A general description of the fuel storage pool design is given in the FSAR,Section 9.1.2 (Ref. 1). A description of the Spent Fuel Pool Cooling andCleanup System is given in the FSAR, Section 9.1.3 (Ref. 2). Theassumptions of the fuel handling accident are given in the FSAR,Section 4 4 515.5.6 (Ref. 3).APPLICABLE SAFETYANALYSESThe minimum water level in the fuel storage pool meets the assumptions of the fuel handling accident described in Regulatory Guide 1.26(Ref.4)1.183 (Ref. 4.) The Total Effective Dose Equivalent (TEDE) forcontrol room occupants, individuals at the exclusion area boundary, and individuals within the low population zone will remain within10 CFR 50.67 (Ref. 5) and Regulatory Position C.4.4 of Regulatory Guide 1.183 for a fuel handling accident.
The 2 hour thyroiddseo per pernsR at the ourv*ohn area is a small fractin Of the10 CFR 100 (Ref. 5) limits.According to Reference 43, there is 23 ft of water between the top of thedamaged fuel bundle and the fuel pool surface during a fuel handlingaccident.
With 23 ft of water, the assumptions of Reference 4 can beused directly.
In practice, this LCO preserves this assumption for the bulkof the fuel in the storage racks. In the case of a single bundle droppedand lying horizontally on top of the spent fuel racks; however, there maybe < 23 ft of water above the top of the fuel bundle and the surface,indicated by the width of the bundle. To offset this smallnon-conservatism, the analysis assumes that all fuel rods fail, althoughanalysis shows that only the first few rows fail from a hypothetical maximum drop.The fuel storage pool water level satisfies Criterion 2 of the NRC PolicyStatement.
(continued)
Watts Bar -Unit 2(developmental)
B 3.7-68AH Fuel Storage Pool Water LevelB 3.7.13BASES (continued)
REFERENCES
: 1. Watts Bar FSAR, Section 9.1.2, "Spent Fuel Storage."
: 2. Watts Bar FSAR, Section 9.1.3, "Spent Fuel Pool Cooling andCleanup System."3. Watts Bar FSAR, Section 5.4 , "Fuel Handling Accident."
: 4. Regulatory Guide 1.25, March 1072, "Assumptions Used forEg'alwat6ng the Potentfial Radiological Gonsogueonces of a Fuel AccideRt iR the Fuel Handling and Storage Facility forBOiling and Pressurized Wat- r Roactors."Regulatory Guide 1.183,"Alternate Source Terms for Evaluation Design BasisAccidents at Nuclear Power Reactors",
July 2000.5. Title 10, Code of Federa! Regulations, Part 100. 11, "Determninatio of Exclu6ion Area, Low Population Zone, and Popu-lation C-enterQDta~e-!Title 10, Code of Federal Regulations, 10 CFR 50.67,"Accident Source Term."Watts Bar -Unit 2(developmental)
B 3.7-70AH Spent Fuel Assembly StorageB 3.7.15B 3.7 PLANT SYSTEMSB 3.7.15 Spent Fuel Assembly StorageBASESBACKGROUND The spent fuel pool contains flux trap rack modules with 1386 storagepositions and that are designed to accommodate new fuel with amaximum enrichment of 4.95 + 0.05 weight percent U-235 and fuel ofvarious initial enrichments when stored in accordance withparagraph 4.3.1.1 in Section 4.3, Fuel Storage.as high a63.8 Weight percen~t UJ 235 withut restrictions.
Storago of fuel assemblies w.,ith enric;hFment beo 3.. 3.8 and 5.0 weight percent requires "ithor fuelburnup in accordance With paragraph 4.3.1.1 or placement in .toragelocations which have face adjacent storage coils coentaining either watero~r fuel Rrassoblioc with accum~ulated bUFrup of at least 20.0 MWDI~gU inaccordance with Spocification 4.3.1.1.The water in the spent fuel storage pool normally contains soluble boron,which results in large subcriticality margins under actual operating conditions.
: However, the NRC guidelines, based upon the accidentcondition in which all soluble poison is assumed to have been lost,specify that the limiting keff of 0.95 be evaluated in the absence of solubleboron. Hence, the design is based on the use of unborated water, whichmaintains the storage racks in a subcritical condition during normaloperation with the racks fully loaded. The double contingency principle discussed in ANSI N-16.1-1975, and the April 1978 NRC letter(Reference
: 1) allows credit for soluble boron under other abnormal oraccident conditions, since only a single accident need be considered atone time. For example, an abnormal scenario could be associated withthe improper loading of a relatively high enrichment, low exposure fuelassembly.
This could potentially increase the criticality of the storageracks. To mitigate these postulated criticality-related events, boron isdissolved in the pool water. Safe operation of the spent fuel storagedesign with no movement of assemblies may therefore be achieved bycontrolling the location of each assembly in accordance with theaccompanying LCO. Prior to movement of an assembly in the pool, it isnecessary to perform SR 3.9.9.1.(continued)
Watts Bar -Unit 2(developmental)
B 3.7-76AH I DC Sources -Operating B 3.8.4BASESBACKGROUND 125 V Vital DC Electrical Power Subsystem (continued)
Additionally, battery boards 1, 11, III, and IV have manual access to the fifthvital battery system. The fifth 125V DC Vital Battery System is intendedto serve as a replacement for any one of the four 125V DC vital batteries during their testing, maintenance, and outages with no loss of systemreliability under any mode of operation.
Each of the vital DC electrical power subsystems provides the controlpower for its associated Class 1 E AC power load group, 6.9 kVswitchgear, and 480 V load centers.
The vital DC electrical powersubsystems also provide DC electrical power to the inverters, which inturn power the AC vital buses. Additionally, they power the emergency DC lighting system.The vital DC power distribution system is described in more detail inBases for LCO 3.8.9, "Distribution System -Operating,"
and LCO 3.8.10,"Distribution Systems -Shutdown."
Each vital battery has adequate storage capacity to carry the requiredload continuously for at least 4 hours in the event of a loss of all ACpower (station blackout) without an accident or for 30 minutes with anaccident considering a single failure.
Load shedding of non-required loads will be performed to achieve the required coping duration for stationblackout conditions.
Each 125 VDC vital battery is separately housed in a ventilated roomapart from its charger and distribution
: centers, except for Vital Battery V.Each subsystem is located in an area separated physically andelectrically from the other subsystem to ensure that a single failure in onesubsystem does not cause a failure in a redundant subsystem.
There isno sharing between redundant Class 1 E subsystems, such as batteries, battery chargers, or distribution panels.The batteries for the vital DC electrical power subsystems are sized toproduce required capacity at 80% of nameplate rating, corresponding towarranted capacity at end of life cycles, de-rated for minimum ambienttemperature and the 100% design demand. The voltage limit is 2.13 Vper coll, Which cOrreSPOnds to a total minimum voltage output of 128 Vper batt,';'
(132 V for Vital Battery, V). The criteria for sizing large leadstorage batteries are defined in IEEE-485 (Ref. 5).(continued)
Watts Bar -Unit 2 B 3.8-49(developmental)
AH DC Sources -Operating B 3.8.4BASESBACKGROUND 125 V Vital DC Electrical Power Subsystem (continued)
The battery cells are of flooded lead acid construction with anominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts per cell (Vpc). For a 58 cellbattery (DG battery),
the total minimum output voltage is 120 V; for a60 cell battery (vital battery) the total minimum output voltage is124 V; and for a 62 cell battery (5th vital battery),
the total minimumoutput voltage is 128 V. The open circuit voltage is the voltagemaintained when there is no charging or discharging.
Once fullycharged, the battery cell will maintain approximately 97% of itscapacity for 30 days without further charging per manufacturer's instructions.
Optimal long term performance,
: however, is obtainedby maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfateand self discharge.
Each Vital DC electrical power subsystem has ample power outputcapacity for the steady state operation of connected loads required duringnormal operation, while at the same time maintaining its battery bank fullycharged.
Each battery charger also has sufficient capacity to restore thebattery bank from the design minimum charge to its fully charged statewithin 12 hours (with accident loads being supplied) following a 30 minuteAC power outage and in approximately 36 hours (while supplying normalsteady state loads following a 2 hour AC power outage),
(Ref. 6).The battery charger is normally in the float-charge mode. Float-charge is the condition in which the charger is supplying theconnected loads and the battery cells are receiving adequate currentto optimally charge the battery.
This assures the internal losses of abattery are overcome and the battery is maintained in a fullycharged state.When desired, the charger can be placed in the equalize mode. Theequalize mode is at a higher voltage than the float mode andcharging current is correspondingly higher. The battery charger isoperated in the equalize mode after a battery discharge or forroutine maintenance.
Following a battery discharge, the batteryrecharge characteristic accepts current at the current limit of thebattery charger (if the discharge was significant, e.g., following abattery service test) until the battery terminal voltage approaches the charger voltage setpoint.
Charging current then reducesexponentially during the remainder of the recharge cycle. Leadcalcium batteries have recharge efficiencies of greater than 91%, soonce at least 110% of the ampere-hours discharged have beenreturned, the battery capacity would be restored to the samecondition as it was prior to the discharge.
This can be monitored by(continued)
Watts Bar -Unit 2 B 3.8-50(developmental)
BH DC Sources -Operating B 3.8.4BASESdirect observation of the exponentially decaying charging current orby evaluating the amp-hours discharged from the battery and amp-hours returned to the battery.(continued)
Watts Bar -Unit 2(developmental)
B 3.8-51BH DC Sources -Operating B 3.8.4BASES (continued)
LCO Four 125V vital DC electrical power subsystems, each vital subsystem channel consisting of a battery bank, associated battery charger and thecorresponding control equipment and interconnecting cabling supplying power to the associated DC bus within the channel; and four DG DCelectrical power subsystems each consisting of a battery, a batterycharger, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE to ensure the availability of therequired power to shut down the reactor and maintain it in a safecondition after an anticipated operational occurrence (AOO) or apostulated 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 threea Notes. T-he-Note 1 indicates that VitalBattery V may be substituted for any of the required vital batteries.
: However, the fifth battery cannot be declared OPERABLE until it isconnected electrically in place of another battery and it has satisfied applicable Surveillance Requirements.
Note 2 indicate that spare vitalchargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vitalchargers.
Note 3 indicate that spare DG chargers IAI, 1B1, 2A1, or2B1 may be substituted for required DG chargers.
: However, thespare charger(s) cannot be declared OPERABLE until it isconnected electrically in place of another charger, and it hassatisfied applicable Surveillance Requirements.
APPLICABILITY The four vital DC electrical power sources and four DG DC electrical power sources are required to be OPERABLE in MODES 1, 2, 3, and 4 toensure safe plant 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 andother vital functions are maintained in the event of a postulated DBA.The DC electrical power requirements for MODES 5 and 6 are addressed in the Bases for LCO 3.8.5, "DC Sources -Shutdown."
(continued)
Watts Bar -Unit 2 B 3.8-53(developmental)
AH DC Sources -Operating B 3.8.4BASESA GTI ON A4/=% -- -- J:L;-- -- AI-OR41Atu
/A rO8epreS ent e vita! Gninnel WKHr a 1966 ef ability LUcomBpletely respond to an evont, and a potontial loss of ability to rmienRegized duFrig nrmF~a! operation.
Rt.i, therefore, imnperatiye that theoperator's attention focus_ on .tabiliin the plant, minimi~zingq the potential for comIplete loss of PG poworA- to the ff~ecGted train. Tho 2 hour limint iscncirstont With the All0owed time for. Rannprbe distributo systemIf one Of the roquirod vital DCG e-lectric4al poWor subs)ystwms is inoperable (e.g., inoperable batter,',
inoperable battory charger(s),
or inoperable battery charger and associated inoereable battery),
the remaining-vital DG electrical power subsystemA has the capacity to support a safeishutdow-nA an;d to mnitigate an accGident condition.
S~ince A su bsequentworst case single failure of the PERmA.BLE SUbsystem; would, however,resut i a ituation Where the ability of the 425V DG electricGal powersubsystem; te support its required ESF function is not assured, continued power eperatien sheuld not eXceed 2 hours6. The 2 hour COMPIAetiGn TimeAis based en Regulator',
Guide 1.93 (Ref. 8) and reflects a roasenable timneto assess plant status as a functioin-of the inopcrable vital DC electrical poere subsystemn and, if the vital DG electrical poWer subsystem is notrestorFed to OPERABLE status, to prepare to effect an orderly and safeif the inoper-able vita! DG electrical power sub6ystmOR cannot be restoredte OPERABLE status within the required Com~pletion Tim~e, the plant Mustbe brought to a MODE in whic-h the LCGO does net apply. To9 achieve thisstatus, the plant mnust be brought to at le-ast MODE 3 within 6 hours andto MODE 5 within 36 hours. The allowed Completion Times are-reasonable, based on operating eXPerience, to reach the required plantcon-ditios fromR full power conditions i an orderly manner ;And Withou tchallenging plant systems.
The Comple~tionR T~i.m._e tobring the plant toMODE 5 is consistent With the timeA required in Regulatory Guide 1.93(Ref. 4.Condition C representG one DG with a losseof ability to completely-respond to an event. SincGe a subsequent single failure onR the eppesitetrain Gould result in a situation; wh~ere the required ESP function is netasSUred, con~tinued power o~peration should net e*ceed 2 hours. The-2 hortime0 lim.it is consR.istent With the allowed tim:e forF an nprbl iaDG Beletrical power subsystem.
(GGRtined)
(continued)
Watts Bar -Unit 2(developmental)
B 3.8-54AH DC Sources -Operating B 3.8.4BASES94If tho DG DG Gnnot be restored toOPERA., 1LE status in the ascctatd Completion, Time, the a6sociatod DG May be incapable of pe~ferming it6 inended-funcAtion and must beimmediat.ly declared R+operable.
This d^+laration al- o require.
9,ntY intoapplicable ConRditions and Requirod Ac-tions Jfr -An ineporable DG, LCOQ3.8.1, "AG SourFGos Operating."
ACTIONS A.1. A.2, A.3. E.1. E.2. and E.3Conditions A and E represent one channel with one battery chargerinoperable (e.g., the voltage limit of SR 3.8.4.1 or SR 3.8.4.2 is notmaintained).
The ACTIONS provide a tiered response that focuseson returning the battery to the fully charged state and restoring afully qualified charger to OPERABLE status in a reasonable timeperiod. Required Actions A.1 and E.1 require that the batteryterminal voltage be restored to greater than or equal to the minimumestablished float voltage within 2 hours. This time provides forreturning the inoperable charger to OPERABLE status or providing an alternate means of restoring battery terminal voltage to greaterthan or equal to the minimum established float voltage.
Restoring the battery terminal voltage to greater than or equal to the minimumestablished float voltage provides good assurance that, within12 hours, the battery will be restored to its recharged condition fromany discharge that might have occurred due to the chargerinoperability.
A discharged battery having terminal voltage of at least theminimum established float voltage indicates that the battery is onthe exponential charging current portion (the second part) of itsrecharge cycle. The time to return a battery to its fully charged stateunder 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 within12 hours, avoiding a premature shutdown with its own attendant risk.(continued)
(eentied)
Watts Bar -Unit 2 B 3.8-55(developmental)
AH DC Sources -Operating B 3.8.4BASESACTIONS A.1, A.2, A.3, E.1, E.2, and E.3 (continued)
If battery terminal float voltage cannot be restored to greater than orequal to the minimum established float voltage within 2 hours, andthe charger is not operating in the current-limiting mode, a faultycharger is indicated.
A faulty charger that is incapable ofmaintaining established battery terminal float voltage does notprovide assurance that it can revert to and operate properly in thecurrent limit mode that is necessary during the recovery periodfollowing a battery discharge event that the DC system is designedfor.If the charger is operating in the current limit mode after 2 hours,that is an indication that the battery is partially discharged and itscapacity margins will be reduced.
The time to return the battery toits fully charged condition in this case is a function of the batterycharger capacity, the amount of loads on the associated DC system,the amount of the previous discharge, and the rechargecharacteristic of the battery.
The charge time can be extensive, andthere is not adequate assurance that it can be recharged within12 hours.Required Actions A.2 and E.2 require that the battery float current beverified less than or equal to 2 amps for the vital battery and lessthan or equal to 1 amp for the DG battery.
This indicates that, if thebattery had been discharged as the result of the inoperable batterycharger, it is now fully capable of supplying the maximum expectedload requirement.
The 2 amp value for the vital battery and theI amp value for the DG battery are based on returning the battery to98% charge and assume a 2% design margin for the battery.
If at theexpiration of the initial 12 hour period the battery float current is notless than or equal to 2 amps for the vital battery or I amp for theDG battery, then this indicates there may be additional batteryproblems and the battery must be declared inoperable.
Required Actions A.3 and E.3 limit the restoration time for theinoperable battery charger to 72 hours. This action is applicable ifan alternate means of restoring battery terminal voltage to greaterthan or equal to the minimum established float voltage has beenused (e.g., balance of plant non-Class IE battery charger).
The72 hour Completion Time reflects a reasonable time to effectrestoration of the qualified battery charger to OPERABLE status.(continued)
(Gentikwed)
Watts Bar -Unit 2 B 3.8-56(developmental)
AH DC Sources -Operating B 3.8.4BASESACTIONS B.1 and F.1(continued)
Conditions B and F represent one channel (subsystem) with onebattery inoperable.
With one battery inoperable, the DC bus is beingsupplied by the OPERABLE battery charger.
Any event that resultsin a loss of the AC bus supporting the battery charger will alsoresult in loss of DC to that subsystem.
Recovery of the AC bus,especially if it is due to a loss of offsite power, will be hampered bythe fact that many of the components necessary for the recovery(e.g., diesel generator control and field flash circuits, AC load shedand diesel generator output circuit breakers, etc.) will likely relyupon the battery.
In addition, any DC load transients that arebeyond the capability of the battery charger and normally requirethe assistance of the battery will not be able to be brought online.The 2 hour limit allows sufficient time to effect restoration of aninoperable battery given that the majority of the conditions that leadto battery inoperability (e.g., loss of battery charger, battery cellvoltage less than 2.07 V, etc.) are identified in Specifications 3.8.4,3.8.5, and 3.8.6 together with additional specific Completion Times.C.1 and G.1Conditions C and G represent a loss of one DC electrical powersubsystem to completely respond to an event, and a potential lossof ability to remain energized during normal operation.
It is,therefore, imperative that the operator's attention focus onstabilizing the unit, minimizing the potential for complete loss of DCpower to the affected subsystem.
The 2 hour limit is consistent withthe allowed time for an inoperable DC distribution subsystem.
(continued)
Watts Bar -Unit 2 B 3.8-57(developmental)
AH DC Sources -Operating B 3.8.4BASESACTIONS D.A and D.2(continued)
If one of the required DC electrical power subsystems is inoperable for reasons other than Conditions A or B for the vital batteries orConditions E or F for the DG DC electrical power subsystem, theremaining DC electrical power subsystem has the capacity tosupport a safe shutdown and to mitigate an accident condition.
Since a subsequent worst case single failure could, however, resultin the loss of the minimum necessary DC electrical subsystems tomitigate a worst case accident, continued power operation shouldnot exceed 2 hours. The 2 hour Completion Time is based onRegulatory Guide 1.93 (Ref. 8) and reflects a reasonable time toassess unit status as a function of the inoperable DC electrical power subsystem and, if the DC electrical power subsystem is notrestored to OPERABLE status, to prepare to effect an orderly andsafe unit shutdown.
If the inoperable Vital DC electrical powersubsystem cannot be restored to OPERABLE status within therequired Completion Time, the plant must be brought to a MODE inwhich the LCO does not apply. To achieve this status, the plantmust be brought to at least MODE 3 within 6 hours and to MODE 5within 36 hours. The allowed Completion Times are reasonable, based on operating experience, to reach the required plantconditions from full power conditions in an orderly manner andwithout challenging plant systems.
The Completion Time to bringthe plant to MODE 5 is consistent with the time required inRegulatory Guide 1.93 (Ref.8).H.1If the DG DC electrical power subsystem cannot be restored toOPERABLE status in the associated Completion Time, theassociated DG may be incapable of performing its intended functionand must be immediately declared inoperable.
This declaration alsorequires entry into applicable Conditions and Required Actions foran inoperable DG, LCO 3.8.1, "AC Sources-Operating."
(continued)
(GGetiAed)
Watts Bar -Unit 2 B 3.8-58(developmental)
AH DC Sources -Operating B 3.8.4BASESSURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the battery chargers, whichsupport char9g4g
,ystem the ability of the batteries to perform theirintended function.
Float charge is the condition in which the charger issupplying the continuous charge required to overcome the internal lossesof a battery (or battery cell) and maintain the battery (or a battery cell) in afully charged state while supplying the continuous steady state loadsof the associated DC subsystem.
On float charge, battery cells willreceive adequate current to optimally charge the battery.
Thevoltage requirements are based on the nominal design voltage ofthe battery and are consistent with the minimum float voltageestablished by the battery manufacturer.
For example, the minimumnominal terminal voltage for the 5th Vital Battery is 136 V (62 cellstimes 2.20 Vpc); the minimum nominal terminal voltage for thevital batteries is 132 V (60 cells times 2.20 Vpc); and the minimumnominal terminal voltage for the DG batteries is 128 V (58 cells times2.20 Vpc). These voltage levels maintain the battery plates in acondition that supports maintaining the grid life.The voltage requirements listed above are based on the critical designvoltage of the battery and are consistent with the initial voltages assumedin the battery sizing calculations.
The 7 day Frequency is consistent withmanufacturer recommendations and IEEE-450 (Ref. 9).SURVEILL.\NCE SR 3.8.4.3(nti~ued)
Verifying that for the vital batteries that the alternate feeder breakers toeach required battery charger is open ensures that independence between the power trains is maintained.
The 7 day Frequency is basedon engineering
: judgment, is consistent with procedural controls governing breaker operation, and ensures correct breaker position.
SR 3.8.4.4This SR demonstrates that the DG 125V DC distribution panel andassociated charger are functioning
: properly, with all required circuitbreakers closed and buses energized from normal power. The 7 dayFrequency takes into account the redundant DG capability and otherindications available in the control room that will alert the operator tosystem malfunctions.
(continued)
(G94Awed)
Watts Bar -Unit 2 B 3.8-59(developmental)
AH DC Sources -Operating B 3.8.4BASESS-R 3-8.4.5-and SR 3.8.".Visual inspection to detect corrosion of tho batter' coil6 and connoctions, Or m~asuromen9t of thoe resitncQ of oach inter cell, *nter rack, inter tfirand- terinlonection, provides an indication Of physical damage orabnormnal doterioration that could potontialy degrade bafttor,The- limits- es99tablisbh-d-forF thiS SR must be no more than 20% above therosistance as me~aur*ed duFrig installation, Or not above the coiling valueesF-t-ablishe-d by the manufacturwer.
The SurelaoFrequency for those inspections, Which can detectconditions th-at c-an cauepwer losses due to resistance heatini92 days. T-his Frequency is considered accoptable based- en oer)ating experience related to detecting corrosion tFreds.99-,444-7 Visual finspection of the b-ater,'
cells, cell plates, and batter,'
rackprovides an indication Of physical damage or abnormnal deterioration thatcould potentially degrade bailr, perfermanco.
The 12 month FrFequency for this SR is consistent with IEEE 450 (Ref. 9),which recomm~en~ds detailed visual inspection Of Gell condition and rackinRtegritY on a YearlY basis.(continued)
(GeRtined)
Watts Bar -Unit 2(developmental)
B 3.8-60AH DC Sources -Operating B 3.8.4BASESSU RVEILLANGE REQUIREMENTS SR 3.8.4.8.
SR 3.8.4.9 and SR 3.8.4.10Visual inspection and resistance mneaurements of inter c9ll, intor rack,inter tier, and- torminal connction provid-e nP ind-ication of physic~al damage Or abnOrMa!
deterioration that could indicate degraded batter;conditwion.
The anti corrosion mnaterial is used to help enSUre good-oloctrical cennoct-iens-and- to reduweq term~inal deterioIrato.
The visualinsooction for orrQoQio i; Anot inodo o ouiro rmova~l of Rnnrpection under each terminal connection...
The Fremo.Val Of Vi.ibcorrosior iS a pre.entiye mnaintenanc.
e SR. The presence o Of corrosion does not necessarily repFreset a failurwe of this SR provi'ded ViIGIEDu GurrF;u 9G wmvU Rng Poriom3nc a 01 9T bK 6.0 or I-OFpurposes Of trending, inter cell (vital and DG batteries) and inter tier (Vitaland DG batteries) connections are measured from batter; post to batter;post. Inter rack (Vital batteries),
inter tier (IDG Batteries),
and terminalconnections (Vital and DG batteries) are measured fromA teFrminal lug tobae~y post,The cnnec~tion resisrta~nce limits for SR 3.8.1.9 and SR 3.8.4.10 shalIl beno Moe% than 20%0 above the resistance as mneasured duringintlao, or not above the ceiling value established by the mnanufacturer-.
The Sur.'eillanco F-Fequencies of 12 moneths is consistent With IEEME 450(Ref. 9), which recommFends cell to cell and term~inal connection-resistance mneasurement on a yearly basis.SR 3.8.4.1This SR requires that each vital batter' charger be capable of Freharging its assocated batter' fromn a capacity Or serVice discharge test whilesupplying normnal leads, or alternatively, operating at cuwrrent limi*t forP Amnmmof 4 hours at a nominal 125 VDC. These requirements arebased on the design Gapasity of the chargers (Ref. 1) and theirperform~ance characteristic of current limfit operation for a substantial portion of the recharge period. Batter,'
charger output current is limited to110% to 125% onf the -200 amAp rated output. R9Gharging the batter,'
otesting forF a minimu;-m of 4 hour is suffiient to verify, the output capabikity of the charger can be sustained, that current limit adjustments areproperly set and that PFotect'ye devices Will not inhibit porfGFrmanco atcurrent limfit settings.
According to Regulator; Guide 1.32 (Ref. 6), thebatter,'
charger supply is requirFed to be-: b--ased-on the !argest combineddemands of the various steady state leads and the Gharging capacity torestore the batter,'
fromn the design minimumF charge state to the fullycharged state, irrespective of the status of the plant during thos~e demandoccurrences.
Verifying the Gapability of the charger to operate insustained currFent limit cnionesrsthat these rqients, can besatisfied.
(continued)
Watts Bar -Unit 2(developmental)
B 3.8-61AH DC Sources -Operating B 3.8.4BASESSURVEII I t\r" SR 3.8.4.11 (continu-d)
REQU IREMENTSThe ~iir"niIhnrn l-rnntinn~v
~ ~ccontiblo olven mc olant conditions requir.ed to perform the test ;;Ad the other admini6.tative c ontr....
xistingto ensure adequate charger performnance during th96e 18 moneth interVals.
in addition, this Frequency is intended to be consistent with expected fue!Thisq SR is- modified by a Note. The reason forF the Note is that perfoFrming the Survoillanco mnay PeotUrb the electric al distribution system and-challenge safe systems.
his Sis AnogRally perFoed duringMODES 5 and 6 since it would require the DC e'ectriGca power subsytemto be inoperable durin~g performnance of the test. HoweVer, thisSurveillance mnay be performned in MOIDES 1, 2, 3, Or 4 provided the Vitalla&#xfd;++a.X.
ig r,, ,ihr.+iti a,'Iq OR waa..ara ith I GOr tdata 1 -r'iraw+
mat, ha *tWJl 1 *fii ., i ta .. ,.tbanfar ian +d ak +nr attneta +i ft +1, ic, D r- vamlan -tnnnnr,evet6 may inGlude:;
&#xfd;Irw" M C3 MCI 0 0 .ncl=I1) UnexPected Gopeational events which causethe equi!pment peor Me dnc.-O ntctuon Bo th I aew'elrloman,-
, icr W,-ni badeeuat dcmntat;ionm Of thA required Derfqrmnance us aVAiWAble and...... .. ...... r --.I-, a:tin tht reuirs peforanceof his I* S..... JL... ~f!4 M, I''I ~ AM DI..... II ....provided the mainRtenanco was required, OF pBefFRmod i ojntowithmainenane rqurd to maintain OPERABILITY Or reliability.
(continued)
Watts Bar -Unit 2(developmental)
B 3.8-62SHI DC Sources -Operating B 3.8.4BASESS URPVEl1l IANICG-E SR -.8.44-2REQU......I.I...R-EME-N..iTS (GGoRiW~.e4
-t-HI6 am....................U..........................................to recharging its associated batter; fromn a capacity or sor.;icoe disccharge testwhile supplyin g normnal loads. T-his roquirmen9t is based on the designcapacity of the chargers (Ref. 13) and their perform~ance characteristic OfcurrenFA-t liMit oporation for a substantial portion Of the recharg PeRiOd.Batter; charger output curren-t is limited-to a maximum-of 140%9 of the20 amAp rated output. Recharging the batter; Verifies the output capability of the chargeFrcan be sustained, that current limit adjustmenRts rproperly ret and that proetec-tive devoices will not inhibit perfoFrmance atcurrent limnit sefttngs.
According to Regulator; Guide 1.32 (Ref. 6), thebailer,'
charger supply is required to be based on th lags combineddemnands of the vOariou,-s steady state Iead6 and the charging capacity torestore the batter' fromA the design miniMmum harge state to the ful~ycharged state, irrespeoct-Ve oaf the s-tatus, of the plant during these demnandoccurrences.
Verif,'ig the capability Of the charger to operate in a6setained cuwrre-nt limit conndmitin esrsthat these eqrmnts can beqsatisfied.
The Surveillance FrFequency is aGceptable, giVen the plant conditions required to perfoFrm the test and the eteramiisrtie otrols existingq to ensure adequate charger performnance during these 18 mon~th intervals.
In addition, this Frequencyi inen edt be consistent with expected fuelGeG&8 e8Rths-.PFo the DG DC eloctrica!
subsystem, this Survoillanco mnay be performned in MODES 1, 2, 3, Or 4 in conjunction With L-GCO .. .)ic the DG DCelectFical power subs6ystem Iuppl-o.lads only for the inoperable; dieselgenerator and would no9t otherxise challenge safet systems6 suppliedfromn vital electrical distribution systems.
A dditionally, credit mnay be takenfor unplanned events that satisf' this SR. Examples of unplanned eventsmay ARGiude*1 ) Unexpected operational eventS which cause the equipmnentt performA the funcionIG specified by this Survoillanco, for which&#xfd;adequate documentaitionof the required performnance Iavailable; aRd2-) PestA ncrrec-tive mnaintenance testing that requires perform~ance of-this Surveillance in order to restore the component toa O-PE-R-A.B-LF-,
provided the mnaintenanc
: wsrqied, Or performed in conjunction Withmnaintenance required to mantIn OPRABILITY Or reliabwlity.
(continued)
Watts Bar -Unit 2(developmental)
B 3.8-63SHI DC Sources -Operating B 3.8.4BASESSURVEiLLANCE R-384.-3REQUIREMENTS4inue) A batter; ....i. e to.t, a .pe.ial Of batter,+
capability, as found, tosatisfy the deign r r ts (batte.,'
duty cYc!. ) of the PG electricalsysteM. T-hodc g Fate and test should toINorst cAs- design dut cc l.e requirements based on References 10The Surveillance FrFequoncy of 18 months is consistent with the-rec..Rmendations of RegulatFo' Guide 1.32 (Ref. 6) and Regulatorp Guide 1.1 29 (Ref. 11), which state that the ba#,e; seVice- test should beperformlced durFng refueling operatioRn orat outage,ith intervals betweeR tests, not to eXceed 18 mROnths.This S-R is- modified by b~s No-tesr.
Note 1 allows- the perfoq~ance of amodified performRance disc-harge test in lieu of a service test once per60 mnonths.
The moAd-ifi~ed perform~ance discharge test is a simulated dutycycle consisting Of just tWo rates: the o-ne minute rate published for thebatter' o the Iargest cu.. ent load Of the duty cycI fo-llowed by the testrate employed for the perform~ance test, both Of which envelope the dutycycl9eof the sepoir.'e test. Since the ampere hours remRoved by a rate-done mnutedischarge represents a very small peotien of the batter'capacity, the test rate can; be changed to that forF the perform~ance testwithout compromnising the result of the performnance discharge test. Thebatter; termin;al voltage for the moqdified perform~ance discharge testshou-ld remain above the minim.. batter' terminal voltage specified inthe batterF se-rvire fFr the dratien Rof time equal to that of the A modified d6hqetest is a test of the cat~ apacity aidits ability t,-, ro!fldi.,
uscharge batter;""
"*,h, and...; to.,
,provide a high rate, 6o94 duration lead (usually the highest rate of theduty GyGle.) This Will oft-e co'nfirmF the ba#tFy's ability to Meet the Fritialperiod of the load duty cycle, in addition to detefRm~inig its percontago ofrated capacity.
Initial conditions forF the moedified performnance discharge test should be these specified for a serv'ie test.The reason for Note 2 is that perfeFrming the Surveillance may peF4Urb the;Aital elecntric-al distr-ibution system and challenge safety systems.However, this SuPIeill~ancc may be perfermoed in MODES 1, 2, 3, or 4provided that Vital Battery V is substituted in accordance withLCO Note 1. For the DG DC e!ectrical subsystem, this suIlPlaSInce maybe perFormed in MODES 1 2, 3, ew i conjunction with 4 3.8 , .B Ysince the supplied loads are only forF the inaperable diesel generator and.would net ether~'ise challenge safety system leads which are supplied(continued)
Watts Bar -Unit 2(developmental)
B 3.8-64FHI DC Sources -Operating B 3.8.4BASESSURVEILLIA\N IGE SR 3.8.4.13 (contin~ued)
REQU IREMVENTS from~ vital electrical distribution systemAS.
Addi4tionally, croFdit mnay be takonfor unplanned eventS that satisfy this SR. Eixamplos of unplanned eyentsFey iRGId9&1 ) Unexpected oporatfional ovonts whic~h cause the equipment to-perfoFrm the, func-tion specified by thi6 SurVoilIaRG9, for Which-adequate documentation of the required performsance is available; and2) Post cor-rocntive m~aintn~anco te-sting that requires pcrf49rmanco Of thisSur.'oillanco in order to restore the comAponent to OPERABLE,-
provided the mnaintenance was required, or pe~rfor-med in conjuncGtion with mnaintenan~e required to maintain GPERDABILIT oj&#xfd;r F liabi~ySR.-2.R4.14 Abatter; performnance discharge test is a test of constant curr~ent capasityof a batter,',
normnally done in the as found-cniin after having' boon in I%I.7 laccoptance test. Thno test is Rtenoea to aee81Frmie oereall battor;14 rraa A .,a A a + n Anl. -nw9rd a tyr-I taw 0 aga dri tood!3W.A batter' moedifiod performance disch~arge test is doscribod in the Basesfor SR 3.8.41.3 Either the batter; perform;anc discharge test Or themodified performance discharge test is acceptable for 6atisfyi~ng SR 3.8.4.14;
: however, only the moedified perform~ance discharge test maybe used to satisfy~
SR 3.8.4.14 while 6atisf,'ing the requirementso SR 3.8.4.13 at the same time.The accepta~nce c~riteria for this Surweillance are consistent With IFEEE 50ID f aX aA 1MCAr ID fX r, c- Yk a.anc f.a .'4'n +ka+ +I-battr, be replaced if its capacity is below 80% of the msanufacturer rating. A capac~ity of 80% shows that the battory rate of deterioration isinc-mar.
inn a 4-n + +hm 0, a ranl +~nntt amttaInzr a,,rr~yvarl orw 5 a P w "apda V M%7 w "d rokati m Uri 5.(continued)
Watts Bar -Unit 2(developmental)
B 3.8-65FHI DC Sources -Operating B 3.8.4BASESSURVEILLANCE SR 3.8.4.14 (continued)
REQUIREMENTS The Su~ilneFrequencY forF this test is nrmFFally 60 mnonths.
if thebatter,'
shows degradation, or if the ba~qoy has, re~ached REM ofitexpoctod life and capacity is 4100% o-f the m~anu-facturerFs rating, theSurVeillance Frequency is reduced to 12 months. However, if the bafteryshoWs no degradation but has roachod 85%0 of its expected life, the8ur~oillance FrFequency is, only reduceAd-to :24 months, for baqtteries thatretain capacit"
:&#xfd;100% Of the .manuRIfacAturer's rating. Degradationi
* ndicated, accordinig to IEEE= 150 (Ref. 0), When the batter! capacitydrops by moreA than I10% relative to itGapacity OR theB preViouspe~feFmaF;Ge tes6t Or When it is ->10% below-4.
thte manu1facturer rating.These Frequece arecnsistent with the recomernedations in IEEE 450(Ref. )This SR is modified by aR Note. The r-eason for the Note is that pe~fGFming the Surveillanae mnay pe~turb the vital electWArica distribution system andchallenge safety systems.
: However, this Suryoillanco may be pe~feFmod in MOIDES I, 2, 3, Or 4 provided that Vital Batteny V is- isubshtit-uted inaccordance with. the- LCO Note. For the- -Q DG- D electrical subsystem, thissur~veillance mnay be pe~fGFmed in MODES I, 2, 3, or 4 in conjunction WithLCOG 3.8.4 .B since the supplied leads are only for the inoperable dioesegenerator and would not etheorwise c~hallen~ge safety system lea;ds whichare supplied fro~m v.it-al electrica!
distribution systems.
Additionally, creditmnay be taken for unplanned events that satisfy' this SR. IExamples ofunplanned 6evets m~ay includ e:1) Un~eXpected operational evoenRts
%which cause the equipment to9-uuIQFui=+H LrnJ+!- ui.url MuGiu4i:3 HU tIiii 01.J.1&#xfd;--
..b... W'.........I ...adequate documen9t-at-ion of the required ponertomancoe is- available; and2) Post corrective msaintenance testinqI that requires qo40frmaRce of thisII Iprovided the maintenance equired, Or poV in, coFnjuntion wit;hm~aintenance required to maintain OPER.AB-ILITY or reliability.
(continued)
Watts Bar -Unit 2(developmental)
B 3.8-66BH DC Sources -Operating B 3.8.4BASES (continued)
SURVEILLANCE REQUIREMENTS (continued)
SR 3.8.4.5 and SR 3.8.4.6These SRs verify the design capacity of the vital and DG batterychargers.
According to Regulatory Guide 1.32 (Ref. 6), the batterycharger supply is recommended to be based on the largestcombined demands of the various steady state loads and thecharging capacity to restore the battery from the design minimumcharge state to the recharged state, irrespective of the status of theunit during these demand occurrences.
Verifying the capability ofthe charger to operate in a sustained current limit condition ensuresthat these requirements can be satisfied.
The SRs provide two options.
One option requires that eachvital battery charger be capable of supplying 200 amps (20 amps forthe DG battery charger) at the minimum established float voltage for4 hours. Recharging the battery or testing for a minimum of 4 hoursis sufficient to verify the output capability of the charger can besustained, that current limit adjustments are properly set and thatprotective devices will not inhibit performance at current limitsettings.
The other option requires that each battery charger be capable ofrecharging the battery after a service test coincident with supplying the largest coincident demands of the various continuous steadystate loads (irrespective of the status of the plant during whichthese demands occur). This level of loading may not normally beavailable following the battery service test and will need to besupplemented with additional loads. The duration for this test maybe longer than the charger sizing criteria since the battery rechargeis affected by float voltage, temperature, and the exponential decayin charging current.
The battery is recharged when the measuredcharging current is < 2 amps for the vital batteries and < I amp forthe DG batteries.
The Surveillance Frequency is acceptable, given the plantconditions required to perform the test and the other administrative controls existing to ensure adequate charger performance duringthese 18 month intervals.
In addition, this Frequency is intended tobe consistent with expected fuel cycle lengths.(continued)
Watts Bar -Unit 2(developmental)
B 3.8-67SH DC Sources -Operating B 3.8.4BASES (continued)
SURVEILLANCE SR 3.8.4.7REQUIREMENTS A battery service test is a special test of battery capability, as(continued) found, to satisfy the design requirements (battery duty cycle) ofthe DC electrical power system. The discharge rate and testlength should correspond to worst case design duty cyclerequirements based on References 10 and 12.The Surveillance Frequency of 18 months is consistent with therecommendations of Regulatory Guide 1.32 (Ref.6) andRegulatory Guide 1.129 (Ref.11),
which state that the batteryservice test should be performed during refueling operations or atsome other outage, with intervals between tests, not to exceed18 months.This SR is modified by two Notes. Note I allows the performance of a modified performance discharge test in lieu of a service test.The modified performance discharge test is a simulated dutycycle consisting of just two rates; the one minute rate published for the battery or the largest current load of the duty cycle,followed by the test rate employed for the performance test, bothof which envelope the duty cycle of the service test. Since theampere-hours removed by a rated one minute discharge represents a very small portion of the battery capacity, the testrate can be changed to that for the performance test withoutcompromising the results of the performance discharge test. Thebattery terminal voltage for the modified performance discharge test should remain above the minimum battery terminal voltagespecified in the battery service test for the duration of time equalto that of the service test.Note 2 allow the plant to take credit for unplanned events thatsatisfy this SR. Examples of unplanned events may include:1) Unexpected operational events which cause the equipment toperform the function specified by this Surveillance, for whichadequate documentation of the required performance isavailable; and2) Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component toOPERABLE, provided the maintenance was required, orperformed in conjunction with maintenance required tomaintain OPERABILITY or reliability.
(continued)
Watts Bar -Unit 2 B 3.8-68(developmental)
BH DC Sources -Operating B 3.8.4BASES (continued)
REFERENCES
: 1. Title 10, Code of Federal Regulations, Part 50, Appendix A,General Design Criterion 17, "Electric Power System."2. Regulatory Guide 1.6, "Independence Between Redundant Standby(Onsite)
Power Sources and Between Their Distribution Systems,"
U.S. Nuclear Regulatory Commission, March 10, 1971.3. IEEE-308-1971, "IEEE Standard Criteria for Class IE PowerSystems for Nuclear Power Generating Stations,"
Institute ofElectrical 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 of Electrical 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 41980i!199, "IEEE RecomFendod Practice forMaintenance Testing and Roplacomont of Large Load Storage-BatteFrie for Generating Stations and Subsystemrs,"
Institute ofElectricnal
,and E!ectronic Engineers.IEEE-450-2002, "IEEERecommended Practice for Maintenance, Testing andReplacement of Vented Lead -Acid Batteries for Stationary Applications,"
Institute of Electrical and Electronics Engineers, Inc.10. :WA Calc'u-ltihn WB.N EEB MS T-1 ! 0003, "125 VDC Vital Batter'and Evaluatien."TVA Calculation EDQ00023620070003, "125V DC Vital Battery System Analysis"
: 11. Regulatory Guide 1.129, "Maintenance Testing and Replacement ofLarge Lead Storage Batteries for Generating Stations andSubsystems,"
U.S. Nuclear Regulatory Commission, February1978.12. TVA Calculation WBN EEB-EDQ00023620070003, "125V DC VitalBattery System Analysis."
: 13. Watts Bar FSAR, Section 8.3.1, "AC Power System."Watts Bar -Unit 2 B 3.8-69(developmental)
SH DC Sources -ShutdownB 3.8.5BASES (continued)
LCO The 125V Vital DC electrical power subsystems, each vital subsystem channel consisting of a battery bank, associated battery charger, and thecorresponding control equipment and interconnecting cabling within thechannel; and the DG DC electrical power subsystems, each consisting ofa battery, a battery charger, and the corresponding control equipment andinterconnecting
: cabling, are required to be OPERABLE to supportrequired trains of the distribution systems required OPERABLE byLCO 3.8.10, "Distribution Systems -Shutdown" and the required DGsrequired OPERABLE by LCO 3.8.2, "AC Sources -Shutdown."
As aminimum, one vital DC electrical power train (i.e., Channels I and Ill, orII and IV) and two DG DC electrical power subsystems (i.e., 1A-A and2A-A or 1 B-B and 2B-B) shall be OPERABLE.
This ensures theavailability of sufficient DC electrical power sources to operate the plant ina safe manner and to mitigate the consequences of postulated eventsduring shutdown (e.g., fuel handling accidents).
The LCO is modified by athree Notes. The-Note I indicates that VitalBattery V may be substituted for any of the required vital batteries.
: However, the fifth battery cannot be declared OPERABLE until it isconnected electrically in place of another battery and it has satisfied applicable Surveillance Requirements.
Note 2 indicates that spare vitalchargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vitalchargers.
Note 3 indicates that spare DG chargers 1A1, 1B1, 2A1, or2B1 may be substituted for required DG chargers.
: However, thespare charger(s) cannot be declared OPERABLE until it is(are)connected electrically in place of another charger, and it hassatisfied applicable Surveillance Requirements.
APPLICABILITY The DC electrical power sources required to be OPERABLE in MODES 5and 6, and during movement of irradiated fuel assemblies, provideassurance 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 arecovered in LCO 3.8.4.(continued)
Watts Bar -Unit 2 B 3.8-63(developmental)
AH DC Sources -ShutdownB 3.8.5BASES (continued)
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 withDC power available may be capable of supporting sufficient systems toallow continuation of CORE ALTERATIONS and fuel movement.
Byallowing the option to declare required features inoperable with theassociated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with the affected required featuresLCO ACTIONS.
In many instances, this option may involve undesired administrative efforts.
Therefore, the allowance for sufficiently conservative actions is made (i.e., to suspend CORE ALTERATIONS, movement of irradiated fuel assemblies, and operations involving positivereactivity additions).
The Required Action to suspend positive reactivity additions does not preclude actions to maintain or increase reactor vesselinventory, provided the required SDM is maintained.
Suspension of these activities shall not preclude completion of actions toestablish a safe conservative condition.
These actions minimizeprobability of the occurrence of postulated events. It is further required toimmediately initiate action to restore the required vital DC electrical powersubsystems and to continue this action until restoration is accomplished in order to provide the necessary DC electrical power to the plant safetysystems.The Completion Time of immediately is consistent with the required timesfor actions requiring prompt attention.
The restoration of the requiredvital DC electrical power subsystems should be completed as quickly aspossible in order to minimize the time during which the plant safetysystems may be without sufficient power.B.1If the-one or more DG DC electrical power subsystem cannot be restoredto OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must beimmediately declared inoperable.
This declaration also requires entry intoapplicable Conditions and Required Actions for an inoperable DG, LCO3.8.2, "AC Sources -Shutdown."
(continued)
Watts Bar -Unit 2 B 3.8-64(developmental)
AH DC Sources -ShutdownB 3.8.5BASES (continued)
SURVEILLANCE REQUIREMENTS SR 3.8.5.1SR 3.8.5.1 requires performance of all Surveillances required bySR 3.8.4.1 through SR 3.8.4.4-47.
Therefore, see the corresponding Bases for LCO 3.8.4 for a discussion of each SR.This SR is modified by a Note. The reason for the Note is to precluderequiring the OPERABLE DC sources from being discharged below theircapability to provide the required power supply or otherwise renderedinoperable during the performance of SRs. It is the intent that these SRsmust still be capable of being met, but actual performance is not required.
REFERENCES
: 1. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6,"Engineered Safety Features."
: 2. Watts Bar FSAR, Section 8.0, "Electric Power."Watts Bar -Unit 2(developmental)
B 3.8-65AH Battery GeU-Parameters B 3.8.6B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.6 Battery Ge94-Parameters BASESBACKGROUND This LCO delineates the limits on battery float current, electrolyte temperature, electrolyte level, and cell float voltage, and spocific for the 125V vital DC electrical power subsystem and the diesel generator (DG) batteries.
A discussion of these batteries and their OPERABILITY requirements is provided in the Bases for LCO 3.8.4, "DC Sources -Operating,"
and LCO 3.8.5, "DC Sources -Shutdown."
Additional controls for various battery parameters are also provided inSpecification 5.7.2.21, "Battery Monitoring and Maintenance Program."
The battery cells are of flooded lead acid construction with a nominalspecific gravity of 1.215. This specific gravity corresponds to an open cellvoltage of 2.07 Volts per cell (Vpc). For a 58 cell battery (DG battery),
thetotal minimum output voltage is 120 V; for a 60 cell battery (vital battery),
the total minimum output voltage is 124 V; and for a 62 cell battery,(51h vital battery),
the total minimum output voltage is 128 V. The opencircuit voltage is the voltage maintained when there is no charging ordischarging.
Once fully charged, the battery cell will maintainapproximately 97% of its capacity for 30 days without further charging permanufacturer's instructions.
Optimal long term performance,
: however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. Thisprovides adequate over-potential, which limits the formation of lead sulfateand self discharge as discussed in FSAR, Chapter 8 (Ref. 4).(continued)
Watts Bar -Unit 2(developmental)
B 3.8-66AH Battery GeU-Parameters B 3.8.6BASES (continued)
APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident (DBA) and transient analyses in the FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assumeEngineered Safety Feature systems are OPERABLE.
The vital DCelectrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during allMODES of operation.
The DG battery systems provide DC power forthe DGs.The OPERABILITY of the DC subsystems is consistent with the initialassumptions of the accident analyses and is based upon meeting thedesign basis of the plant. This includes maintaining at least one train ofDC sources OPERABLE 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 aee-parameters satisfy the Criterion 3 of the NRC PolicyStatement.
LCOBattery aee-parameters must remain within acceptable limits to ensureavailability of the required DC power to shut down the reactor andmaintain it in a safe condition after an anticipated operational occurrence or a postulated DBA. Ele-Gtel&#xfd;teBattery parameter limits areconservatively established, allowing continued DC electrical systemfunction even with Category A and- B limits not met. Additional controls for various battery parameters are also provided inSpecification 5.7.2.21, "Battery Monitoring and Maintenance Program."
APPLICABILITY The battery aG9-parameters are required solely for the support of theassociated vital DC and DG DC electrical power subsystems.
Therefore, battery eleGtre9hy4e
-sparameter limits are only required when the DCpower source is required to be OPERABLE.
Refer to the Applicability discussion in Bases for LCO 3.8.4 and LCO 3.8.5.(continued)
Watts Bar -Unit 2(developmental)
B 3.8-67AH Battery B 3.8.6BASES (continued)
AGTIQNlt A ..........
.. II_ .... ....... L=! .... L ___'_LL_'=
i! --MvTtn oneRA or1 more c I As in 9 on F or oe oRaIIoRies not1 w RItni imiRS k" -,Category A limits not mnet, Category B limits; not met, or Category A and BliMit6 not mnet) but within the Category C limfitG Gpocified in Table 3.8.6 1... .-..... ......,, ,. .m r O.. no.J............-.
.J --....-~.. ... ...,v .........
in thA nnnA gaF;%1*Ag LGQ the ba#ecu *r, d9CIFaded but theFe 4r* 6tilla4ffected WAtt, sntrqie ob osdrdioeal sol1ely as aresult of Category A or B limi~t6 not mnet, and operation
-6 permnited for aliiedfpe~iGEI The pilot Goelectrolyt4e leyel and float Yoltage are required to be verifiedto mooet the Category C limit Within 1 hour (Required Action A.1). T-hischeck Will proVide a quick iniainof the status rcf the remainder Of thebatter' cells. One hour providesA tilme to inspect the electrolyte level andto confiFrm the float voltage of the pilot c8lls. Onie hour is considered areaRsonabl e amonunt of timne to ee-drfom.
the renquired-v~eqrfic~ationF.
% / ;.r. +; +k + +11 t- + f, 1; ;+ + 0 ; A A +;provides assurance that during the time needed to restore the parame~ters to the Categor,'
A and B limits, the battery is, still capable of pe~f9Fming Itsintended fUR4tio.
A period- of 24 hour is F;allowed to comnplete the 9 taverification because specifi gravity mneasurements must be obtained foreach cOnn~ected cell. Takin~g *into consideration both the time required top9efGrm the Fequired Verification and the assurance that the batter' Gel!parameters agre not rseverelY
: degraded, this tim~e is, coAnsid~ereAd_
re.;r9asonabl.
The verfication is repeated at 7 day intorvals until theparameters are restored to Category
,A ,and B limits. This periodiverificOationA is consistent
.wfith the noArmFal FrequencGy Of pilot cell-Continued oporation is only permitted for 31 days be fore battery ~ellparame~ters mus1t be4 res6toreAd to_ within Category A. and B limnits.
With theconsi6deration that, while battery capact isdgrdd, sufficient capacityeXists tOp normF~ the intended function ndto lo time to fuly restorethe batter' cell parameters, to normnal limits,1 thiS time is acceptable prier todocAinkun the b~atter iRnonrabhLo.
: j. ... -(continued)
Watts Bar- Unit 2(developmental)
B 3.8-68AH Battery Gell-Parameters B 3.8.6BASES,ACTIONS 84(GORtiRued)
With one or more8 batteries With 9Re Or MoA-re- bhaA#er,'
Goil parame;ter outside the Catgor, C Imi,,ts for any
: ci11, capacity tosupply thoeaiu 1erpoctd load Fegu*roment 0s not assurod and thecorrespondin
;ia Co DG DG e!octrical poWor subsystemn must bedoclaroed inoeporable.
Additionally, othor potontially oXreFme conditions, SUch as not Gom.pleting the Re.uirod Act8QiRn of Condition A within thoreguirod Completion Timo oravrae&8etrl1o4 teMprature ofreprGesetative co1ls falling below 602F for the vital batt1eries or 500F forDGbateieare als1asefrimeitl declaFrin the associlated vital DG Or DG DG oloctrical power subsystem inoperable.
ACTIONS A.I. A.2. CA,. C.2, and C.3If one required vital battery or one required DG battery has one ormore cell voltage < 2.07 V, the battery is considered degraded.
Within 2 hours, verification of the required battery chargerOPERABILITY is made by monitoring the battery terminal voltage(SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state of charge bymonitoring 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 performthe intended function.
Therefore, the affected battery is not requiredto be considered inoperable solely as a result of one or more cells inone battery < 2.07 V and continued operation is permitted for alimited period up to 24 hours.Since the Required Actions only specify "perform,"
a failure of SR3.8.4.1, SR 3.8.6.1, SR 3.8.4.2, or SR 3.8.6.2 acceptance criteria doesnot result in this Required Action not met. However, if one of theSRs is failed, the appropriate Condition(s),
depending on the causeof the failures, is entered.
If SR 3.8.6.1 or SR 3.8.6.2 is failed, thenthere is not assurance that there is still sufficient battery capacity toperform 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 requiredDG battery with float current > 1 amp indicates that a partialdischarge of the battery capacity has occurred.
This may be due toa temporary loss of a battery charger or possibly due to one or morebattery cells in a low voltage condition reflecting some loss ofcapacity.
Within 2 hours, verification of the required battery chargerOPERABILITY is made by monitoring the battery terminal voltage.(continued)
Watts Bar -Unit 2 B 3.8-69(developmental)
AH Battery GeU-Parameters B 3.8.6BASESACTIONS B.1. B.2, D.1. and D.2 (continued)
If the terminal voltage is found to be less than the minimumestablished float voltage, there are two possibilities, the batterycharger is inoperable or is operating in the current limit mode.Conditions A and C address charger inoperability.
If the charger isoperating in the current limit mode after 2 hours, that is anindication that the battery has been substantially discharged andlikely cannot perform its required design functions.
The time toreturn the battery to its fully charged condition in this case is afunction of the battery charger capacity, the amount of loads on theassociated DC system, the amount of the previous discharge, andthe recharge characteristic of the battery.
The charge time can beextensive, and there is not adequate assurance that it can berecharged within 12 hours (Required Actions B.2 and C.2). Thebattery must therefore be declared inoperable.
If the float voltage is found to be satisfactory, but there are one ormore battery cells with float voltage less than 2.07 V, the associated "OR" statement in Condition H is applicable and the battery must bedeclared inoperable immediately.
If float voltage is satisfactory andthere are no cells less than 2.07 V, there is good assurance that,within 12 hours, the battery will be restored to its recharged 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) acrossits terminals indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. Thetime to return a battery to its recharged state under this condition issimply a function of the amount of the previous discharge and therecharge characteristic of the battery.
Thus, there is goodassurance of fully recharging the battery within 12 hours, avoiding apremature shutdown with its own attendant risk.If the condition is due to one or more cells in a low voltage condition but still greater than 2.07 V and float voltage is found to besatisfactory, this is not indication of a substantially discharged battery and 12 hours is a reasonable time prior to declaring thebattery inoperable.
Since Required Actions B.1 and C.1 only specify "perform,"
a failureof SR 3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in theRequired Action not met.However, if SR 3.8.4.1 or SR 3.8.4.2 is failed, the appropriate Condition(s),
depending on the cause of the failure, is entered.(continued)
Watts Bar -Unit 2 B 3.8-70(developmental)
AH Battery ,eII-Parameters B 3.8.6BASESACTIONS(continued)
E.1. E.2. and E.3With one required vital or DG battery with one or more cellselectrolyte level above the top of the plates, but below the minimumestablished design limits, the battery still retains sufficient capacityto perform the intended function.
Therefore, the affected battery isnot required to be considered inoperable solely as a result ofelectrolyte level not met. Within 31 days, the minimum established design limits for electrolyte level must be re-established.
With electrolyte level below the top of the plates, there is a potential for dryout and plate degradation.
Required Actions E.1 and E.2address this potential as well as provisions in Specification 5.7.2.21.b, "Battery Monitoring and Maintenance Program."
They aremodified by a Note that indicates they are only applicable ifelectrolyte level is below the top of the plates. Within 8 hours, levelis required to be restored to above the top of the plates. TheRequired Action E.2 requirement to verify that there is no leakage byvisual inspection and the Specification 5.7.2.21.b item to initiateaction to equalize and test in accordance with manufacturer's recommendation are taken from IEEE Standard 450. They areperformed following the restoration of the electrolyte level to abovethe top of the plates. Based on the results of the manufacturer's recommended testing the battery may have to be declaredinoperable and the affected cell(s) replaced.
F.1With one required vital or DG battery with pilot cell temperature lessthan the minimum established design limits, 12 hours is allowed torestore the temperature to within limits. A low electrolyte temperature limits the current and power available.
Since thebattery is sized with margin, while battery capacity is degraded, sufficient capacity exists to perform the intended function and theaffected battery is not required to be considered inoperable solelyas a result of the pilot cell temperature not met.(continued)
Watts Bar -Unit 2(developmental)
B 3.8-71AH Battery Gel4-Parameters B 3.8.6BASESACTIONS(continued)
G.1With more than one required vital or more than one required DGbatteries with battery parameters not within limits as specified inConditions A through F there is not sufficient assurance that batterycapacity has not been affected to the degree that the batteries canstill 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 uponthe batteries.
The longer Completion Times specified for batteryparameters on non-redundant batteries not within limits aretherefore not appropriate, and the parameters must be restored towithin limits on at least one subsystem within 2 hours.H.1With one or more batteries with any battery parameter outside theallowances of the Required Actions for Condition A, B, C, D, E,F or G, sufficient capacity to supply the maximum expected loadrequirement is not assured and the corresponding battery must bedeclared inoperable.
Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 V and floatcurrent greater than 2 amps for the vital batteries or 1 amp for theDG batteries indicates that the battery capacity may not be sufficient to perform the intended functions.
Under these conditions, thebattery must be declared inoperable immediately.
(continued)
Watts Bar -Unit 2(developmental)
B 3.8-72AH Battery ,eU-Parameters B 3.8.6BASESSURVEOLLA.NGE SR 3.8.64REQUIREMENTS This 2SR verifirs that Catogo- ; A batt'o Gel' .a..tr ..o cosstnwith IEEE1450 (Rof. 2), Whi:h rocommondS ba#e,'. inspetrions (at least ono per moenth) including
: voltage, 6pecific
: grayity, and 8'ectrolyte temporature Of pilot cells.SR Tho 'uarterly inSPectio n9f specific gravity and voltage s cofnsistont withIEEE 450 (Ref. 2). In addition, within 21 hour" of a batter,'
dischaFrg
-c110 V (1 13.5-V for Vital Batter; V or 106.5 V for DG battories) or abatter,'
overcharge
>- 150 V. (1 55 V for Vital Battor,'
V or 1145 V. forDG batteries),
the batter; must be de-monstr-ated-to Meet Category B9li.mi*ts.
Tran;;sientS, such as mo~tor starting transients, which m:ayLmomenGtarily cause batter,'voltage to drop to 110V (113.5 Vfor VitalBatter; V or 1068.5 V for DG battorios),
do not constitute a batter;-discharge provided the batter' term~inal voltage and float current retuIrn topro transient values. This inspection isa!so consistent with .1EEE 450(Ref. 2), which recoAGm.men8ds special inspections following a seVeredischarge Or overcharge, to ensurwe that no significant degradation of thebatter; occurs as a consequence Of SUch discharge Or overcharge.
This Survoillance verificationA that the average temperature ofrapresentatiVo cells is ! 600F for the vital batteries, and ! 50"F for theDG batteries, 06 consistent with a recommFendation of IEEE=F 450 (Ref. 2),that s-taRtesR that the temnperatureF of electrolytes in representative cellsshould be deteFrmined on a quarterly basis.(continued)
Watts Bar -Unit 2(developmental)
B 3.8-73AH Battery ,e4-Parameters B 3.8.6BASESRI IRIEII I AIICE SR 3.8.6 (GOntnuord)
REQUIREME.NTS Lowor .....thAn nrMa tem.peratures act to ihibit orh ro.duco ' capacity.
T-his SR ensureAs-that tho operating tomApGratures romain within anaccoptablo operating range. This limnit is based an mnanUfacturor roconMMenAdations.
Table 3.8.6 IThis table dolinoatos the limits on oloctrolyte level, float voltage,-anid Tpecific graVity f or thret drifferent tego'ri ... The of accateger,'
is discussed belowA.gCateogeo' A delfinReF thoe OIal limit for each desigrated coA-l in oacRAh batter,.
The cells seloctod as pilot Goils -Are thoseA whoco6tomnPoratUro,
: voltage, and electrolye spccific gravity approxim~ate theState Of charge of the entire batter,'.
The Categor,'
A limits specified for oloctro','t level are based enmsanufactrer recommF:enda;-tions[
and- are con~sistent with the guidance iIEEE 450 (Ref. 2), with the extra .1nc,4 lwac above the high waterlevel iRndiation for operatiq ng argin to accoun--t for temperatures andcharge effects.
In -aCdditionR to this. allowanco, footnote (a) to Table 3.8.6 1perm~its the electrolyte level to- be- -above the specified maximum levelIduring equal'iig charge, provided it is not OvoF:oW*Rg.
Those limitsenAsure that the plates suffer no physical damage, and that adequateelectFro transfercapabilipF ir, maintained in the event Of transient-conditions.
IEEFE 450 (Ref. 2) recommends that electrolye level readingsshudbe mnade only after the bhatter, has boon at float charge for at leastT7 he togd2Th Gat1e. .. .. .limi Lp~ fe JG 90a ........
2.1 V: .... eell r_{ 16iu 0;Rsf- paOR IRA M rocmmnouGnS OT Intm 'iow kr. d), WRucRiStates that prolonged operation of cells 4 2.13 V can reduce the lifeexpectancy of colls.The Categer,'
A limit specified for specific gravity for each pilot cell is> 1.200 (0.015 below the manufacturer fully charged nominal specificqraVity or a batter,'
charging current that had- Stabilized at a low value).This value is characteristic ofta charge-d cell1 with adequate capacity.
ArrGdinFg to IEEE 450 (Ref. 2), the specific gravity readings are basedon a tem-eratur' of 77&deg;F (250C).V-._ _ \__ w j_(continued)
Watts Bar -Unit 2(developmental)
B 3.8-74AH Battery ,eU-Parameters B 3.8.6BASESSURVEILL'ANCE SR 3.9.@.3 (con~tin~ud)
REQUIREMENTS; Tk^ P^t* c&#xfd;n~~ nrr. ^^ n~ ,npr rrnntnM far gnt #a -I nrn.Ai c t, "20C 4 a'70t- k "770C '3r.Ofl I +(0.001) is added to the reading; 1 point iS f.r each ,oF be.ow770P. The specific gIr ai of IItho oet&#xfd;rolyte in a cell increasos with a lossof water due to or e-aporation.
Category B defines the normaI ParFameteFr limlit fr9 each connected Geil.The term, "connoc3ted cel!" excludes any batte, il that may bejumApred Out.The Category B3 limits specified for electrolyt!ee lo and float Yeltage arethe same as those specified for Categor~'
A and have boon discusse13d above. The Category B3 limit specified for specific gravity for each4connected
%1il is ! 1. 195 (0.020 below the man;ufacturer fuly charged,nem~inal specific gravity)
With the aYeragc of all connected calls >1.205(0.010 below the mqanufacturer fuly charged, Gnoinal 6pecific gravity).
These values AreA ba6Red on manufac~t~urer's recommendations.
Theminmu speific gravity value required for each cell1 ensures that theeffectIs
-of a;; highly charged or neWly inIstaled coil wilIIIl not Mask overalldegradation of the batery.&#xfd;Category C defines the limits for each cell. These values,although
: reduced, provide assurance that sufficent capacity exists toperformA the intended function and mnaintain a mnargin of safet. When anybattery parameter is outside the Category C limits, the assurance ofsufficient capacity described above no lon~ger exists, and the battery mnustbe declared inoperable.
The Gateaor; C limits specified for eloctrol~e leyel (above the top of theLL =l IL = -I--i= -- + ....Iplates ana not OVO......g.
ensure Mal !Re plafs 6U-,F or no pRysicaldamage and mnaintain adequate electFro transfer capability.Th Category C li.mits fo-r float# voltage is ba~se~d onA IEEE 450 (Ref. 2), whichstates that a cell voltage of 2.07 V or below, under float conditions andnot caused by elevated temperatue of the Gl', irdicates internal cellproblems and May roquire cell replacemnent.
The Cwategory C limFits of average specific gravity 115ibaeonR manufacturer recommendations (0.020 below the manufactJurerF recommended fully ch~arged, nominal specific gravity).
In addition to thatlimnit, it is required that the specific gravity forF each cnen~ecnted-cell mu st beno) less than 0.020 below the average of all connected cells. This limitens'-res that the effect of a highly charged or neW cell does not maskoveaell 4dAradatior of the ............
.1"(continued)
Watts Bar -Unit 2(developmental)
B 3.8-75AH Battery Ge4-Parameters B 3.8.6BASESS1UIRVED\I I AlQ l F-REQUIREMENTS SR 3.80.6.3 (continUod)
X Ino MAeotnote to- 4i polo ui-A1 are aoeiicaoio To 6a19ooorv A .1na uRR..... ...... FE ..........
... -j --7 -spociti gravity.
ootnote (b) to Tal 30 .9.6 1 requi'r4Rs-the ahQovementioned corection for olocrolyto9 level and temperature, withthexception that !eyel correc-tionA i6 not required when batter; charginig cu-'rArnt is; 2 amps OR float charge for vital b~attrioc and -1.0 amps forDG batteies.
This currenFtA
: provides, in general.
an indication of oereallBersause of specifics gravity gradients that are produced during threcharging
: process, delays Of several days May occur While waitfing forthe specific gravity to stabilize.
A stabilized charger current is aacceptable alternative to specific graVity mneasuremen~t for doteFRmining thesta-te Of charge. This phenomenon is discusse i~n IEEEF 450(Rf2)Cnnnnf I n^ T-,hi- '1 9 fi I ,Ipp.th^
finp* ^1,r tq g-rrnt t g) , ea 'can alte"rate to SpeiAfGc f-r Up to 31 days followinr a ba'te,',recharge.
Within 31 days, each connected cell's specific gravity mAust beme-&#xfd;;-asurd-to- cn-firmn the sotate of chage. Following a minorG batter;recharge (such as equalizing charge that does not fellw a deep-discharge),
specific graVity gradients are no~t Significant, and conf4Frming me~asuremen8ts May be8 made in less than 31 days.-SURVEILLANCE REQUIREMENTS SR 3.8.6.1 and SR 3.8.6.2Verifying battery float current while on float charge is used todetermine the state of charge of the battery.
Float charge is thecondition in which the charger is supplying the continuous chargerequired to overcome the internal losses of a battery and maintainthe battery in a charged state. The equipment used to monitor floatcurrent must have the necessary accuracy and resolution tomeasure electrical currents in the expected range. The float currentrequirements are based on the float current indicative of a chargedbattery.
The 7 day Frequency is consistent with IEEE-450 (Ref. 2).This SR is modified by a Note that states the float currentrequirement is not required to be met when battery terminal voltageis less than the minimum established float voltage of SR 3.8.4.1 orSR 3.8.4.2.
When this float voltage is not maintained, the RequiredActions of LCO 3.8.4 ACTION A or E are being taken, which providethe necessary and appropriate verifications of the battery condition.
Furthermore, the float current limit of 2 amps for the vital batteryand 1 amp for the DG battery is established based on the nominalfloat voltage value and is not directly applicable when this voltage isnot maintained.
Watts Bar -Unit 2(developmental)
B 3.8-76AH Battery Ge1-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)
SR 3.8.6.3 and SR 3.8.6.6Optimal long term battery performance is obtained by maintaining float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer which is2.20 Vpc. This corresponds to a terminal voltage of 128 V for theDG batteries, 132 V for vital batteries I through IV and 136 V forvital battery V. The specified float voltage provides adequateover-potential, which limits the formation of lead sulfate andself discharge, which could eventually render the battery inoperable.
Float voltages in this range or less, but greater than 2.07 Vpc, areaddressed in Specification 5.7.2.21.
SRs 3.8.6.3 and 3.8.6.6 requireverification that the cell float voltages are equal to or greater thanthe short term absolute minimum voltage of 2.07 V.The Frequency for cell voltage verification every 31 days for pilotcell and 92 days 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 sufferno physical damage and maintain adequate electron transfercapability.
The minimum design electrolyte level is the minimumlevel indication mark on the battery cell jar. The Frequency isconsistent with IEEE-450 (Ref. 2).SR 3.8.6.5This Surveillance verifies that the pilot cell temperature is greaterthan or equal to the minimum established design limit (i.e., 60 *F forvital batteries and 50 &deg;F for DG batteries).
Pilot cell electrolyte temperature is maintained above this temperature to assure thebattery can provide the required current and voltage to meet thedesign requirements.
Temperature lower than assumed in batterysizing calculations will not ensure battery capacity is sufficient toperform its design function.
The Frequency is consistent withIEEE-450 (Ref. 2).design requirements.
Watts Bar -Unit 2(developmental)
B 3.8-77AH Battery eI4-Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.7REQUIREMENTS A battery performance discharge test is a test of battery capacity(continued) using constant current.
The test is intended to determine overallbattery degradation due to age and usage.Either the battery performance discharge test or the modifiedperformance discharge test is acceptable for satisfying SR 3.8.6.7;however, only the modified performance discharge test may be usedto satisfy the battery service test requirements of SR 3.8.4.7.A modified performance test is a test of the battery capacity and itsability to provide a high rate, short duration load (usually the highestrate of the duty cycle). This will often confirm the battery's ability tomeet the load duty cycle, in addition to determining its percentage ofrated capacity.
Initial conditions for the modified performance discharge test should be identical to those specified for a servicetest.It may consist of just two rates; for instance the one minute rate forthe battery or the largest current load of the duty cycle, followed bythe test rate employed for the performance test, both of whichenvelope the duty cycle of the service test. Since the ampere-hours removed by a one minute discharge represents a very small portionof the battery capacity, the test rate can be changed to that for theperformance test without compromising the results of theperformance discharge test. The battery terminal voltage for themodified performance discharge test must remain above theminimum battery terminal voltage specified in the battery servicetest for the duration of time equal to that of the service test.The acceptance criteria for this Surveillance are consistent withIEEE-450 (Ref. 2) and IEEE-485 (Ref. 3). These references recommend that the battery be replaced if its capacity is below 80%of the manufacturer's rating. A capacity of 80% shows that thebattery rate of deterioration is increasing, even if there is amplecapacity to meet the load requirements.
Furthermore, the battery issized to meet the assumed duty cycle loads when the battery designcapacity reaches this 80% limit.Watts Bar -Unit 2 B 3.8-78(developmental)
AH Battery GeU-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS SR 3.8.6.7 (continued)
The Surveillance Frequency for this test is normally 60 months. Ifthe battery shows degradation, or if the battery has reached 85% ofits expected life and capacity is < 100% of the manufacturer's rating,the Surveillance Frequency is reduced to 12 months. However, ifthe battery shows no degradation but has reached 85% of itsexpected life, the Surveillance Frequency is only reduced to24 months for batteries that retain capacity
> 100% of themanufacturer's ratings.
Degradation is indicated, according toIEEE-450 (Ref. 2), when the battery capacity drops by more than 10%relative to its capacity on the previous performance test or when it is> 10% below the manufacturer's rating. These Frequencies areconsistent with the recommendations in IEEE-450 (Ref. 2).This SR is modified by a Note. The reason for the Note is to allowthe 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 toperform the function specified by this Surveillance for whichadequate documentation of the required performance isavailable; and2. Post corrective maintenance testing that requires performance ofthis Surveillance in order to restore the component toOPERABLE, provided the maintenance was required, orperformed in conjunction with maintenance required to maintainOPERABILITY or reliability.
REFERENCES
: 1. Watts Bar FSAR, Section 15, "Accident Analysis,"
and Section 6,"Engineered Safety Features."
2.A XXX L A J IEEE 450t 1I39U.14995,
'ThL+/- ReocommA-Ondod P-raotico forB3attorio forF GonReating Statioew-and- Subc-htationsn-."IEEE Std 450-2002, "IEEE Recommended Practice for Maintenance, Testingand Replacement of Vented Lead -Acid Batteries forStationary Applications,"
Institute of Electrical and Electronics Engineers, Inc.3. IEEE Std 485-1983, "IEEE Recommended Practice for SizingLarge Lead Storage Batteries for Generating Stations andSubstations,"
The Institute of Electrical and Electronics Engineers, Inc.4. Watts Bar FSAR, Section 8, "Electric Power."Watts Bar -Unit 2(developmental)
B 3.8-79AH Battery GeU-Parameters B 3.8.6BASESWatts Bar -Unit 2(developmental)
B 3.8-80AH Contn"ment Penetratio-nSTHIS SECTION NOT USEDB 3.9.4B 3.9 REFUELING OPERATIONS B 3.9.4 Centainment PenetrAtionsTHIS SECTION NOT USEDDuring moGVRemen-t Of irra-d-iat-d-fuel1 aseble ithin con-t;4ainment, arelease of fisrsion product radioactivity within containment will be9 restricted from; escaping to the enViFronment WhenA the LCQ requiremnents are met.In MODES 1, 2, 3, and 4, thiG i6 accOMplichod by maintaining containment OPERABLE as described in LCGO 3.6.1, "Containment."
InMODE 6, the potential for con-tainmenA-t pressuriZation as a result Of anaccident is not likely; therefore, requirements to isolate the containment from the utsde atmosGphe-re can be9 loss Stringent.
The LCGOrequirements are referre~d to as, "contaRin.ment closure" ra;ther than;"containment OPERABILITY."
Containment closure mneans that al!potontiaI escape paths are closed Or capable of bein~g closed. Sincethere is no potential for co~tiAFnment pressurization, the Appendix jleakage criteria and tests are not required.
The- containm~ent 6orYes to contain fission product radioactivity that Maybe released froM the reactorF core follown an acident, such that offsiteradiation exposures are mnaintained well wthinR theA ire quir FeMenRts of10 CFR 100. Additionally, the containment provides radiation shieldingq from- the fission products that m~ay be pr9eset in the- containm.entA atmosphere following accident conditieons.
The containm~ent equipment hatch, which is part of the containment pressure bounder,,
provides-6
-A means for mo;ving lag eqimnt a;ndcomnponents into and ou t of containment.
During movLe.ment Of irradiated fuel assemblies within containment, the equipment hatch m~ust be hold inplace by at least four bolts. Good enginern pracItice dictates thaRt thebel1ts required by this LCO be approximately equally spaced.The containment air locks, which are also part Of the containment-pressure bGun~dar,,
provide a means for personnel access duFringMODES 1, 2, 3, and 4 unit oper-ation in accordancGe with LCOQ 3.6.2,"Containment Air Locks." Each air lock has a dIoor at both ends. Thedoors are nermally finterlocked to prevent simultaneu openig whencontainmen9t OPErRAR"I!T is required.
During Periods, of unit shutdon;s
.When conRtainment closure iS not required, the door in~terleck mnechanism may be disabled, allowing both doors Of an air lock to remnain open forextended periods when frequent centainment ont ,' is nesa. During(eo~ed)Watts Bar -Unit 2(developmental)
B 3.9-11AH Containment Penetratiens
-843.4BACKGROUND (G~eRt4~ed) mo-voment of irradiated fuol assemblies Within containment, containment closuro i6 required; therefor9e, the door may remairdieabed, u n wl~,dprr~M h aaeO 9fGh '-irm 't frtnt-imn nntitn erirdn.ir ht~releaeof fission prFoduc4t radioa4cvity Within will e re Ftfictedto within regulatory imnits.The BuildinRg urge Ventilation SyStemt operate.
to .u.pplyoutside aiMito the onanmn for venRtilation and cooling or heating, toequalize internal and external pressures, and to reduce the co-ncnmtr-ation Of noble gaseS Within containmenRt prior to and during personnel access.The supply and exhaust l"nes each contain Won isolation valves. Becwau seof their largqe 6, the 24 inch containm.on.
t l. O ,.r compatment pur.evalves are physically Frestricted to!!; 50 degrees open. The Ro-aceBuilding Purge and System can be opened inMODES 5 and 6, but are closed automatically by the EnRgineered SafetyFeat-ues.AcntuatioRn System (ESFAS).
In MODE 65, air exhangesare necessar-y o 9onduict refueling opeations.
The normal 24 inch purgesystem is used for this purpose.
The ventilation system mnust be eitherw solatod OFr capable of being automatically iselated upon detection of highradiation levels wi0thin containmient.
T-he o-ther coantainment penetrations that provide direct access froAmcontainment atmospher-e to outside atmosphere m~ust be isolate~d on Atleast one sidle. slto-a eahee ya PR.L uoaiisolation; valve, or by a maulioainvalve, blind flange, Or equivalent.
Eiale isoltiornor method s must be approved and may ilude use of amaterial that can provide a temprary, atmospheric
: pressure, ventilation brirfo-r the ether containmenRt penetrations during fuel moGv8emets (Ref. 1). ClOsure by ether valves Or blind flanges may be used if they aresimilar in capability to those provided for containment irsolation.
T-heseAm;ay be conStructed of standardI materials and may be justified on thebasis of eithe-r nor-mal an;alycis methods or reasonable engineern judgment (Ref. 4).A P PLIC GABL e IDuring movement of irradiated fuel as-se-mblierbmswihn cnanet theSAFETYmost severe radielegical consequences result fromR a fuel handlingANIALYS&#xfd; accident.
The fuelA- handling acc~ident is a postulated event that involvesdamage to irradiated fuel (Ref. 2). Fuel handling accidents, Inayzed iRe-feqrence-R
-2, include drogpping a single irradated fuel assembly-and-handling tool Or a heavy ebject onto other irradiated-fuel assrem~blies.
Watts Bar Unit 2B 6onta'AInmon Pdonotra!ions 84.44BASES.APPLI'C-A
'BLERA F;EmTYLThe requ-eirements of LCOQ 3.9.7, "Refueling Cavity Water Level," inconjunction With a minimumu~
decay time of 100 hours prior to irradiated ful-- moVe-men-t-with c-ontainmenRt closuF9recapability en;SureS that therlAse f flss*on product ra;dnioactivity, subeGu~ent to A fue h ndlingacciden~t, results in doese that are well within the guideline Yaluespecified in 10 CER 100. Standard RevieW Plan, Section 16.7.4, Rev. 1(Ref. 3), defines "well within" 10 CFR 100 to bhe- :25% or loss- of the10- C-FR 100 val-uesr.
Thie acceptanco limitS for offitot radiation exposuree will be 25%0 of 10Q CErR 100 values or the NRC staff approved iesgbaums IR n~. ra seecifd frac;tion o~f 10 CPR 100Q limit)Containent peetrat*Gons sat*f' Criterion 3 of the NRC PolicyStatemelt.
Thist LG HFl kst~ the rsnseRWnAtncnf ef a fiuel handlin, arrident in....-4-f- r...A.l .,..radioactivity released WithiR contanment.
The LCQO requieres any-penetration pro9viding direct accGss fromn the GgntainM9nt atmos~phere tethe outside atmoGsphere to be closed eXcept for the OPERA\BLE ReactorBuilding Purge and Ventilation System penetrations, and the containme.t personnel a*Fle.k..
ForF the-A OPEZR.BLE Building Purge andVen-ti--rla-t System penetration, this LC ensures that thesepenetrations
-are- isowl-able by the Containment Ventilation
!solati~ln SystemA.+Re WIIKJE !I=-+ r ogiumn r LflIS LGO enswer thati the autematpurge and exhaust v-alve- closuire tie6pecifed in the F=S.AR can beanchieved-and, therefore9, meeqAt the- asmtosused
~nthe safety-analysis to e-nsu--re t-ha-;t rlae th-rough the valves are terminated, SUchthat radielogical doses are within the acceptance limit.The Gontainment personnel air'oock doors may be open during movemnent of irrFadiated fuel iR the Ggntainment providted-tha-t onRe deer is capable ofbeing closed- in the event of A fuel hanRdl~ing acciden~t an~d provided thatABT is OPERA~VBLE OR accoruanco With TS~ 3.7.12. Should a 'ehandling accident occGur inside contaiment, one personnel airlock doerwill be closed foallowing an eyacuation of contaiment.
The LCO ismedified by a NoAte- all-owing penetration flew paths with direct -accessfromA the Geontainment atmorsphere to the outside atmosphere tobunisolate-d iunderB admnitraivGcotrls Admninistrative controls ensurethat 1) appropriate personnel are aware of the open status of the-penetration flow path durin movmet of irrad-iated-fuelA- &#xfd;assemblies WONR GGRtaiR ent: 21 SmeGified ORdiy4duals aFe de6k]Rated aRd readliv(GGRtieWd)
WAaft Bar Unit 2A 69MenaIRnmOn Pd8netrzuionR B 3.94BASES8L-Go3) ponotration flow paths, penetrating the Auxiliary Building Socondar,'
(G94Rtued)
Containment Enclos6uro (ABSCE=)
boundar-y, are limited to less than the" bmroch allOWaRnc; ard 4) the ABGTS is OPERA.Er inaCCordance wi;th TS- 3-7.12. Operability of A1BGTS- is required to ,alleviate the consequences of an FHA insi~de containment resUlting in leakage Ofairborne Fadieoancive matei~wal past the open airlock Or penetration flowpathsG prior to their closu re-..APPLI[C-AB-ILITY The containm~ent penetration requiremnents are applicable duringmov'ement of irradiatod fu-1e assemblies wthin containment because thisis whern there i,- a potential for the fuel haRdling accide-nt.
InMODES 1, 2, 3, and 4, containmenRt penetration requiremnents are-addressed by LCO 3.6.1. In MODES 5 and 6, when movement of-irradatedfuelassemlieswithn cotainment is net bein~g conducted, thepotential for a fuel handling accident nRt exist. Therefore, underthese condition no equremets are placed On; containm~ent penetration 6tatu6.If the- con-ta-inment equipmen~t h~atch, air locks, or an" cntainm~ent penetration that provides direct access from the containment atmosphere to the outside atmosph~ere 16 net in the required status, including theCon-t~ainmen-t VenRtilation Isolatian System net capable of automaiataion hen the purge and exhaust valves are open, the unit mRust beplaced in a GenditiGR where the isolation fucinis nt needed. This isaccomplished by immediately suspending movement of iF~adiatod fuelassem~blies wIAthiN conA-t-ainment.
Performance of these acin hall notpreclude com~pletion of mevement of a comAponent to a safe PGsit*Gn.
SURVEILL\ANCE R-3.44REQUIREMENTS This Sur~eillanca demonsRtrates that each of the containment penetrations required to be in it closed position is in that position.
The Survoillance on the open purge and exhaust valves will demonstrate that the valves,are not bloc-ked frm.-m closing.
Also the Survoillanco will demon~strate thateach valve operatorF moFtiVe PoweF, which will ensure that each valveis capable of being closed by an O-PERA.LR utemWAce nventRilationisoatosinl Wl;tts Bar UJnit 2(dy 0GmntlB 3.9 44A Containment Penetrations B 3.9.4BASESSUR VI:E I AL'lrC QF SR 3.9.1.1 (continued)
REQU REMENTSa.,a,7 Ai A. re Cl.. ^fa -nnnra,a 00 rMv WIrcp cx-ro or H EMULI! -- .... A--! ....irra a aite e T... .. A .M. I. ..w itn In c o n TAin m .. .. ...ntIll II iJselepLed
$t ht; commenlirtef with the normal 911Fulrn or f!m9 tot1I P II I acomnplete fuel handling operations.
A sur~lllanco before theo start ofrefueling operations will provide two or three sUrYoilIRARc Verifications during the applicable period forF this; LCO. As sucoh, this Surveillance ensures that a postulated fuel handling accident that releases fissionproduct radioactivity within the containm~ent Will not reSUlt ina release ofsignificant fis6ion product radio~Acivity to the enViFromen~t in exos 9fthosbe reconmmenR8ded by Standard ReViewM PlanM Section 15.7.4 (Ref. 3).This Surveillanc~e demonstates that each containmenAt purge and exhaustvalve actuates to its isolation position on mnanual initiation Or On an actualor simulated high radiation signal. The 18 mRonth FrequencY m~aintains consistency With ether similar ESFAS itrmnaonand valve testingrequirem~ents.
LCGO 3.3.6, "Containm~ent Ventilation Isolation; Instrumentation,"
requires a CHANNEL CHECGK ever' 12 hours and aCOT- ever,' 92 days to ensrWe the channel O)PERABILITV durling refueling operations.
EvYer' 18 mon9ths, a CHANNELI CALIBRATION is pe~fGFmed.
The soystem actuation reGponse time isdmntaed ever 18 months,dur~ing refueling, On a STAGGERED TEST BASIS. SR 3.65.3.4de~monstratews that the i~solation time of each valve is in; accordRance Withthe Inser~ice Testing Prora requrents.
These Survellancos peofermed during MODE 6 w.~ill nsr that the valves are capable ofclesing a#fte a postulated fuel handl'ing accidenRt to limtarelas offissio.'n oroduct radioactivity from the GGntainment.
4,;"Us F;e o-f S~iliconGe Sealant to Maintain Con(9taRinmen9t lntegrity ITS.May 20, 98&-Watts Ba;r FSAR, Section 15.4.5, "Fuel H4andling Accident.
NUREG 0800, Standard Review Plan, Section; 15.7.4. "Radolpeica 4-.Lonsnuenes f Ruel Hanclino Acci-dents:
Keyv. I. Juiv I MI.UIGeneric Loller 88 17. "Loss of Decay Heat Removal."
WAtt~s Bar Unit 2a Refueling Cavity Water LevelB 3.9.7B 3.9 REFUELING OPERATIONS B 3.9.7 Refueling Cavity Water LevelBASESBACKGROUND The movement of irradiated fuel assemblies within containment requires aminimum water level of 23 ft above the top of the reactor vessel flange.During refueling, this maintains sufficient water level in the containment, refueling canal, fuel transfer canal, refueling cavity, and spent fuel pool.Sufficient water is necessary to retain iodine fission product activity in thewater in the event of a fuel handling accident (Refs. 1 and 25). Sufficient iodine activity would be retained to limit offsite doses from the accident to-25%0 of 1 0 CFR 100 limits, as proVided by the guidance ofRtfeie--
the limits defined in 10 CFR 50.67 (Ref. 4) andRegulatory Position C.4.4 of Regulatory Guide 1.183 (Ref. 5).APPLICABLE SAFETYANALYSESDuring movement of irradiated fuel assemblies, the water level in therefueling canal and the refueling cavity is an initial condition designparameter in the analysis of a fuel handling accident in containment,-ae-postulated by Regulato.y Guide 1.25 (Ref. 1). A minimum water level of23 ft (Regulatory Position G-,---2 of Ref-4Appendix B to Regulatory Guide 1.183) allows an overall iodinea decontamination factor of40-200 (Regulatory Position G.1.9. of Ref. 1) to be used in the accidentanalysis fGF iedine. This relates to the assumption that 99% of the totaliodine released from the pellet to cladding gap of all the dropped fuelassembly rods is retained by the refueling cavity water. The fuel pellet tocladding gap is assumed to contain 8% of the 1-131, 10% of the Kr-85,and 5% of the other noble gases and iodines from the total fissionproduct inventory in accordance with Regulatory Position ofRegulatory Guide 1.183total fuel red iodine ine'ntory (Ref. 1) exGcpt for1134 Which is assumed to be 12% (Ref. 6).The fuel handling accident analysis inside containment is described inReference
: 21. With a minimum water level of 23 ft and a minimum decaytime of 100 hours prior to fuel handling, the analysis and test programsdemonstrate that the iodine release due to a postulated fuel handlingaccident is adequately captured by the water and offsite doses aremaintained within allowable limits (Refs. 4 and 5).Refueling cavity water level satisfies Criterion 2 of the NRC PolicyStatement.
(continued)
Watts Bar -Unit 2(developmental)
B 3.9-20AH Refueling Cavity Water LevelB 3.9.7BASES (continued)
LCOA minimum refueling cavity water level of 23 ft above the reactor vesselflange is required to ensure that the radiological consequences of apostulated fuel handling accident inside containment are withinacceptable limits, as provided by the guidance of Reference 32.APPLICABILITY LCO 3.9.7 is applicable when moving irradiated fuel assemblies withincontainment.
The LCO minimizes the possibility of a fuel handlingaccident in containment that is beyond the assumptions of the safetyanalysis.
If irradiated fuel assemblies are not present in containment, there can be no significant radioactivity release as a result of a postulated fuel handling accident.
Requirements for fuel handling accidents in thespent fuel pool are covered by LCO 3.7.13, "Fuel Storage Pool WaterLevel."ACTIONSA.1With a water level of < 23 ft above the top of the reactor vessel flange, alloperations involving movement of irradiated fuel assemblies within thecontainment shall be suspended immediately to ensure that a fuelhandling accident cannot occur. The suspension of fuel movement shallnot preclude completion of movement of a component to a safe position.
A.2In addition to immediately suspending movement of irradiated fuel,actions to restore refueling cavity water level must be initiated immediately.
SURVEILLANCE REQUIREMENTS SR 3.9.7.1Verification of a minimum water level of 23 ft above the top of the reactorvessel flange ensures that the design basis for the analysis of thepostulated fuel handling accident during refueling operations is met.Water at the required level above the top of the reactor vessel flangelimits the consequences of damaged fuel rods that are postulated toresult from a fuel handling accident inside containment (Ref. 21).The Frequency of 24 hours is based on engineering judgment and isconsidered adequate in view of the large volume of water and the normalprocedural controls of valve positions, which make significant unplanned level changes unlikely.
(continued)
Watts Bar -Unit 2(developmental)
B 3.9-21AH Refueling Cavity Water LevelB 3.9.7BASES (continued)
REFERENCES i I I IRegulator:
Guide 1.25, "Aceump~tIOnS Used tor Eyalwatlneivme li*i_
/'%WAeTenTIa
-~Al iicia -GRceciU6REcv 8+ a IrUe I 01RzIno-RIAnt.
:.ociuoit in the; Fuoal andhng and Soag Faclty for Boiling andProessurizoed-Water ReactoFrs,"
U.S. Nucloar Rogulator,'
Commission, March 23, 197-2-.21. Watts Bar FSAR, Section 15.4.5, "Fuel Handling Accident."
: 32. NUREG-0800, "Standard Review Plan," Section 15.7.4,"Radiological Consequences of Fuel-Handling Accidents,"
U.S. Nuclear Regulatory Commission.
: 43. Title 10, Code of Federal Regulations, Part 20.1201 (a), (a)(1),and (2)(2), "Occupational Dose Limits for Adults."-o" "tj ft , ..1 tp , ..1 " ", ., am t;Vt7C2"tV-,-a-.,
JAI~ ni~. I~aeio~oaicai uoncoouencoc OT a i-uoi ~ano~ina5g.Accident, December 197!.Title 10, Code of Federal Regulations, 10 CFR 50.67, Accident Source Term."NURE&GCR 5000, "Assessiment of the UIS-3 Of EXtend8d BuFRnUPFuel in Light Water PoWer Reactors,"
U. S. Nuclear Regulatory Commission, Februarjy 1g8.Regulatory Guide 1.183, "Alternate Source Terms for Evaluation Design Basis Accidents atNuclear Power Reactors,"
July 2000.Watts Bar -Unit 2(developmental)
B 3.9-22AH ReacztorF Buildine Purgne A~ir Cle-anu44UtsTHIS SECTION NOT USEDB 3.9.8B 3.9 REFUELING OPERATIONS B 3.9.8 Reactor Building Purge A.i Cleanup UnWt THIS SECTION NOT USEDBASESThe4 Reactor Building Purge Air Cleanup Units are aenierdsafet feature of the Reactor Building Purg8 Venltilation System hih snoR Safety feature VentilatioR SY-t-m. The ai-r cleaRup unit containprefiltw"s, HEPA filters, 2 inch thick charcoal ador{brS, hous'ings andductwork.
Anytime fuel handling oper-ations are being carried an insidethe primnary containm~ent, either the containment Ventilation Will be-isolated Or the Reactor Building Purgo air cleanup units Will beOPERA.BLE (Ref. 1).The Reactor Bufilding Purge Ventilation SystemR provide6 mechanical Yentilation of the prim~ary con~tainm~ent, the instrum~ent room located withinthe containment, and the ann-dulu.
The4 systemn i6 designed to Supplyfresh air forF breathing and contamination controel to allow pFersonne acGc6s for mainateRane and refue~ing operation6s--
Th.e aust air isfiltered by the Reactor Building Purge Air Ceanup Unitsm to limit therelease of radio~activity to the enviF4ronment.
The conRtainmqent upper and lower G9ompa~tments aro purged with fresh airby the Reactor Building Purge Ventilation System before oc.upancy.
Theannu.u. can be purged with fresh air during reactor sh.utdowR or at times::hen the annUIUS vacuumn cOntro systemA of the EmRergency Gas-Treatmfent System is shut down. The instrumont roo is purgd withfr61;h air d.ruring operation of the, Reaor,,,,
Building Purge Ventilation System Or *i separatey purged by the InRstFrument Roo PurgeSubsystem..
All purge ventilation are non Safety relatetdThe Reazicwr ounuInoR Pdurue Ventiiaugn OYStoM 1s SiZefg 1o DrOVIGOI *
* i II *iadequate ventilation Tor personnei to ponrmFF Wor~ nsiao the pr ImrcontaiRnment and the annulus during al! normal eperatiens.
In the even9-t Ofa fuel handling the Reacrto BuildiRn Purge VenIl;atio SysteM *ii solated.
The Reactor Building Purge Air Cleanup Units are always-available as passive i,;nline to peOFrm their functionimmwnediately after a fuel handling acciden.
t to process activity exhaust air before it reaches the outsid-e enAvironenMGt.
kGwniped)
Watts Bar -Unit 2(developmental)
B 3.9-27AH I Wt1eactor WWF96in Aure Gler~iaRUp) un4133.9.9RASESBACKGROUND The PrFinmar containment oxhaust is monitorted by a radiation deteGtor(G9RtiRued)
Which provides c contai- n nment pruge olatinupon detocting the sotpoinRt randio;activty Rn the exhaust air streamR.
Thecnonntainment purge VSnt;ilation n vialvyes
, Will bhO automIGAticOally clGoedup'n the actuation of a Vent lon (\II\ (GVI) .ignal the ontainnment is being purged during RFnoral operfiWn or uponmanual actut iotn from tho Main CnCtrol Room (Ref. 2). Requirements for CntOnmen Ret Vent lme&#xf7;ation Instrumentation are oevered by ICnO 3.3.6.APPLICABL P The Reactor Building Purge Vertilation System,; Goaup units ensrureSAFETY+ that the rl of to the eAnviFronment is limited by ineanihig Up G\ntainment exhaust during a fuel handling acmident befor FhecontaiRnment purge exhaust valvesb arse isolated.
Reactor Building PurgeVoni&#xf7;aio lSystemr filter effichi on,-6 Gne Of the inputs for the analysis ofthe envro;Gnmental consequences6 of a fuel handling accident.
Containment isolation can only result in smnaller releases of radioactivity to theon men oAiG t (Ref. i1o The Gontainmnt VeRnt Isolation SystemAnsures that the containment vent ,and purge peRetrationR will bautomatically isolated upon detection of high radiation levels within thecontaiF;nment (Ref. 2). Containment Vent Isol-ation Iruettini address~ed by LCO 3.3.6.The Reactor Building Purge Air Cleanup Un~its satisfy' Criterion 3 Of theNRC Policy Statement.
In addition, during moGv9emet of irradiated fuel in the Auxiliar-y BuildigWheR contaiRnment iS open to the Auxiliary Building
: spacses, a hig-hradiation signal fro-m the- spent fuel peol acciden~t radiation monitors
, aConAtainm.enAt Isolation Phase A (SI sign~al) frogm the oporating unit, hightemRperature in; the Auxiliary Building air intakes, or manul ABI wil initia;te a CVI. In the case where the cOntaiRnmenAt.
of. botFuitS is open to theAuxiliary Building spaces, a CVI in one unit Will initiate a CVI in the otheruiinord-er to.m.aintain those spaces open to the ABSCEF.The safety func~tion of the Reactor Bui4lding Purge Air Cleanu1p Unit isrelated to the initia! contre! o-f oF.t raito xoures resulting
#fro afuel handling accident insido GGGntainmnt Duig a fuel hand~ling accient nsie ntainment, the Reactor Building Purge Air Cleanup Unitprovides a filtered path forF clean~ing up any air leaYing the containment un-til the cneptainment ventilationilioatdBr Unit 2(dvlopmetl)
--a-toFr IiI-d*RQ UFIrq A lAOF (;'GaRUP IJ133.9.8LGQ(Ge4Rued)
The plant design i,-; s that WhBnA moing irradiated fuel in theA uxi'iar' Building o~!FG1tiMFtWiht9G~aR~~
pen theAwmvia,-
Building A S ,
I m the -pen fu.l 0 RE 90 102 and 103 Will initiate a CVI in addition to theirnorFm-Al funcRAtion.
In aRddi@tion, a 6ignal frmthe coentiainmFent purge radiation 2 RE( 9(0 130, and 1 3 r OFthr CIVI -ignal Will iRitiate thatpllin of the AB-RI normally initiated by the spent fuel pool radiati omonitors.
A~dditionally, a CnametIotinPhase A (SI signal) fromthe operatinRg unit, high temnperature in the Aumiliari Building airinaksor manual ABI1 will cause a CVI signal inR the refueling unit. T-hereforFe, thecontainment
-ventoiation instrumentatlon mustt remain operable whenmoing, irr-adiated fuel in the uildiRng if the c-ntainFmen t penetrations, equipmfent hatch, etc. are open to the Auxiliary BuildingABSCE= spaces. In addition, the ABGTS must remain operable if theseconRtain.mnt penetrations are open to the Auxiliary Building durng,@movement of iFradiated fuel in side conAtainmenAt.
In the case where thecontaiRnment of both units is open; to the Auxiliary Buildingq spaces, a CVIin one- 'unit Will initiatte a C-VI in the_ o-therF unit in order to minai thoseqspaceG open to the ABSCE.APPLICABILIT An initial assumption in the analysis of a fuel handling accident isd that the taccidet occus whileat hdhandletd_.
Therefore, LCO 3.9.8 is applicable only at thiS ti~m~e. seead-dition~al discussionr_,(9 in the Applicable Safety Analysis and L=,CO sections.
AGT-IONS
_.Ia~ .if one Roaster Building Purge Air Cleanup Unit is ineperable, that airceanup unit m.us;t bhe islated.
This places the system in the requiredaccident thus allowing refueling to r-antinue afer- erifyingthe eminn air cleanup unit Is aligned and OPERABLE.
The imeit ompletion T-ime is consistAnt With the required times, fonractions to be pe~fermed without delay and in a con~troalled mannr.WAI-+s Bar UnIt 2(dove lopme ntal)B 3.929GI M A 1 AII i tLReactor tiuMidin l-'urg Air Cleanup Wnt1349.8ACTIONS(GGetRued) 984WiAth tWon Re-actor Building Purge Air Cloanup Units inoperable, MoQVomo;nt o9f iraitdfuel assemblies_
wIAthin conQtainm~ent mAust b9 suspended.
This prec'udes the possibility of a fuel han~d!ing accident in cOntaiRnment
.. ith both ReActor Bu ilding Purge AiF Cloanup Unitsinprbe Performa~nce of ths cion shall noGt preclud9 moInG l omoent to asafe peste;*rThe immediate Completion Time is consistent With the required times forFactAions, to bhe performned without delay and in a controlled m4annrS'JRVEILLANICE RR34REQU IREMENTSThe_
Filter Tes-ting ProgrFam (VF\TDP) the Building Purge Air Cleanup Unit filter tests in accordance with Regulatory' Guide 1.52 (Ref. 3). The VFTP includes testing the performance of theHEPA filter, charco-al
-adeorbsrer efficiency, miiu .f.lew rate, and thephysical prope~tios of the actiyated charcoal.
Specific test rFreqecsand aditinal nfor at~nae discussed in detail in t-heA VFRTP.REFERE- CE 4,~ W~ats Bar FSAR, Section 15.5.6, "Einvironmental Consoquencos Ofa Postulated FuelA_ Hand-ling Accident."
2- Watts Bar FSAR, Section 0.4.6, "Reactor Building Purge Ventilat~ing system.3, Regulatory Guide 1.52 (Rev. 02), "IDesign, T-esting and-Maintenan
.Criteria for Pest AGccdent Engineered Safety FeatureAtmesphere l.ean.p System A;r rFltration and Adsorptieon Units ofLight Water Cooled Nuclear Power Plants."IAIAtts Bar Unit 2R 29-30A Decay Time3.9.10B 3.9 REFUELING OPERATIONS B 3.9.10 Decay TimeBASESBACKGROUND Section 15.5.6 of the Watts Bar FSAR (Ref. 1) defines theassumptions of the fuel handling accident radiological
: analysis, including a minimum decay time for irradiated fuel assemblies priorto movement.
This assumption ensures that the inventory ofradioactive isotopes is at a level that supports the safety analysisassumptions.
To ensure that irradiated fuel assemblies have decayed for theappropriate period of time, a limitation is established to require thereactor core to be subcritical for a time period at least equivalent tothe minimum decay time assumption in the fuel handling analysisprior to allowing irradiated fuel to be moved.Given that no irradiated fuel assembly will be moved outside of thecontainment until the minimum decay time requirement is met, thisrequirement also ensures that any irradiated fuel assemblies thatare moved outside of the containment meet the decay timeassumption in the radiological analysis of the fuel handlingaccident.
APPLICABLE SAFETYANALYSESThe radiological analysis of the fuel handling accident (Ref. 1)assumes a minimum decay time prior to movement of irradiated fuelassemblies.
The requirements of LCO 3.3.7, "Control RoomEmergency Ventilation System (CREVS) Actuation Instrumentation,"
LCO 3.7.10, "Control Room Emergency Ventilation System(CREVS),"
LCO 3.7.11, "Control Room Emergency Air Temperature Control System (CREATCS),"
and LCO 3.9.7, "Refueling CavityWater Level," in conjunction with a minimum decay time of 100hours prior to irradiated fuel movement ensures that the release offission product radioactivity, subsequent to a fuel handling
: accident, results in doses that are within the requirements of 10 CFR 50.67(Ref. 2) and Regulatory Position C.4.4 of Regulatory Guide 1.183(Ref. 3).The decay time satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).
(continued)
Watts Bar -Unit 2 B 3.9-26Technical Requirements (developmental)
H Decay Time3.9.10BASES (continued)
LCOA minimum decay time of 100 hours is required prior to movingirradiated fuel assemblies within containment.
This preserves anassumption in the fuel handling accident analysis (Ref. 1), andensures that the radiological consequences of a postulated fuelhandling accident inside containment are within acceptable limits.APPLICABILITY This LCO applies during movement of irradiated fuel assemblies within the containment, since the potential for a release of fissionproducts exists.ACTIONSA.1When the initial conditions for prevention of an accident cannot bemet, steps should be taken to preclude the accident from occurring.
When the reactor is subcritical for < 100 hours, movement ofirradiated fuel assemblies within containment must be suspended.
This action precludes the possibility of a fuel handling accident incontainment.
This action does not preclude moving a fuel assemblyto a safe position.
The immediate Completion Time is consistent with the requiredtimes for actions to be performed without delay and in a controlled manner.SURVEILLANCE REQUIREMENTS TSR 3.9.10.1This SR verifies that the reactor has been subcritical for at least100 hours prior to moving irradiated fuel assemblies by confirming the date and time of subcriticality.
This ensures that any irradiated fuel assemblies have decayed for at least 100 hours prior tomovement.
The Frequency of "Prior to movement of irradiated fuelin the containment" is appropriate, because it ensures that thedecay time requirement has been met just prior to moving theirradiated fuel.(continued)
Watts Bar -Unit 2 B 3.9-27Technical Requirements (developmental)
H Decay TimeB 3.9.10BASES (continued)
REFERENCES
: 1. Watts Bar FSAR, Section 15.5.6, "Environmental Consequences of a Postulated Fuel Handling Accident."
: 2. Title 10, Code of Federal Regulations, 10 CFR 50.67, "Accident Source Term."Watts Bar -Unit 2 B 3.9-28Technical Requirements (developmental)
H ATTACHMENT 3WBN Unit 2 TS and TSB Developmental Revision H(Optical Media Storage)}}

Revision as of 09:13, 3 July 2018

Synopsis of Revisions Included in Watts Bar Unit 2 Developmental Revision H of Technical Specifications and Technical Specification Bases. Part 2 of 2
ML13357A051
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Site: Watts Bar Tennessee Valley Authority icon.png
Issue date: 12/12/2013
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Text

RCS Specific ActivityB 3.4.16BASES (continued)

APPLICABLE SAFETYANALYSESThe LCO limits on the specific activity of the reactor coolant ensures thatthe resulting 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> doses at the site boundary and Main Control Roomaccident doses will not exceed the appropriate 10 CFR 100 doseguideline limits and 10 CFR 50, Appendix A, GDC 19 dose guideline limits following a SGTR or MSLB accident.

The SGTR and MSLB safetyanalysis (Ref. 2) assumes the specific activity of the reactor coolant at theLCO limit and an existing reactor coolant steam generator (SG) tubeleakage rate of 150 gallons per day (GPD). The safety analysis assumesthe specific activity of the secondary coolant at its limit of 0.1 1iCi/gmDOSE EQUIVALENT 1-131 from LCO 3.7.14, "Secondary SpecificActivity."

The analysis for the SGTR and MSLB accidents establish the acceptance limits for RCS specific activity.

Reference to these analyses is used toassess changes to the unit that could affect RCS specific

activity, as theyrelate to the acceptance limits.The analyses are for two cases of reactor coolant specific activity.

Onecase assumes specific activity at 0.265 PCi/gm DOSE EQUIVALENT 1-131 with an iodine spike immediately after the accident that increases the iodine activity in the reactor coolant by a factor of 500 times the iodineproduction rate necessary to maintain a steady state iodine concentration of 0.265 jiCi/gm DOSE EQUIVALENT 1-131. The second case assumesthe initial reactor coolant iodine activity at 2-1-14 pICi/gm DOSEEQUIVALENT 1-131 due to a pre-accident iodine spike caused by anRCS transient.

In both cases, the noble gas activity in the reactor coolantequals the LCO limit of 100/E tpCi/gm for gross specific activity.

The analysis also assumes a loss of offsite power at the same time as theSGTR and MSLB event. The SGTR causes a reduction in reactor coolantinventory.

The reduction initiates a reactor trip from a low pressurizer pressure signal or an RCS overtemperature AT signal. The MSLB resultsin a reactor trip due to low steam pressure.

The coincident loss of offsite power causes the steam dump valves toclose to protect the condenser.

The rise in pressure in the ruptured SGdischarges radioactively contaminated steam to the atmosphere throughthe SG power operated relief valves and the main steam safety valves.The unaffected SGs remove core decay heat by venting steam to theatmosphere until the cooldown ends.(continued)

IWatts Bar -Unit 2(developmental)

B 3.4-84BHI RCS Specific ActivityB 3.4.16BASESAPPLICABLE SAFETYANALYSES(continued)

The safety analysis shows the radiological consequences of an SGTRand MSLB accident are within the appropriate 10 CFR 100 and10 CFR 50, Appendix A, GDC 19 dose guideline limits. Operation withiodine specific activity levels greater than the LCO limit is permissible, ifthe activity levels do not exceed 241-14 ýtCi/gm DOSE EQUIVALENT 1-131, in the applicable specification, for more than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The safetyanalysis has concurrent and pre-accident iodine spiking levels up to24-14 piCi/gm DOSE EQUIVALENT 1-131.The limits on RCS specific activity are also used for establishing standardization in radiation shielding and plant personnel radiation protection practices.

RCS specific activity satisfies Criterion 2 of the NRC Policy Statement.

ILCOThe specific iodine activity is limited to 0.265 tiCi/gm DOSEEQUIVALENT 1-131, and the gross specific activity in the reactor coolantis limited to the number of piCi/gm equal to 100 divided by E (averagedisintegration energy of the sum of the average beta and gammaenergies of the coolant nuclides).

The limit on DOSE EQUIVALENT 1-131ensures the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> thyroid dose to an individual at the site boundary andaccident dose to personnel in the Main Control Room during the DesignBasis Accident (DBA) will be within the allowed thyroid dose. The limit ongross specific activity ensures the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> whole body dose to anindividual at the site boundary and accident dose to personnel in the MainControl Room during the DBA will be within the allowed whole body dose.The SGTR and MSLB accident analysis (Ref. 2) shows that the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />site boundary dose levels and Main Control Room accident dose arewithin acceptable limits. Violation of the LCO may result in reactorcoolant radioactivity levels that could, in the event of a SGTR or MSLB,lead to site boundary doses that exceed the 10 CFR 100 dose guideline limits, or Main Control Room accident dose that exceed the 10 CFR 50,Appendix A, GDC 19 dose limits.(continued)

Watts Bar -Unit 2(developmental)

B 3.4-85A RCS Specific ActivityB 3.4.16BASES (continued)

APPLICABILITY In MODES 1 and 2, and in MODE 3 with RCS average temperature

_> 5000F, operation within the LCO limits for DOSE EQUIVALENT 1-131and gross specific activity are necessary to contain the potential consequences of an accident to within the acceptable Main Control Roomand site boundary dose values.For operation in MODE 3 with RCS average temperature

< 5000F, and inMODES 4 and 5, the release of radioactivity in the event of a SGTR isunlikely since the saturation pressure of the reactor coolant is below thelift pressure settings of the main steam safety valves.ACTIONSA.1 and A.2With the DOSE EQUIVALENT 1-131 greater than the LCO limit, samplesat intervals of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> must be taken to demonstrate that the limit of24-14 gCi/gm is not exceeded.

The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> isrequired to obtain and analyze a sample. Sampling is done to continue toprovide a trend.The DOSE EQUIVALENT 1-131 must be restored to within limits within48 hours. The Completion Time of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is required, if the limitviolation resulted from normal iodine spiking.A Note permits the use of the provisions of LCO 3.0.4.c.

This allowance permits entry into the applicable MODE(S) while relying on the ACTIONS.This allowance is acceptable due to the significant conservatism incorporated into the specific activity limit, the low probability of an eventwhich is limiting due to exceeding this limit, and the ability to restoretransient specific activity excursions while the plant remains at, orproceeds to power operation.

I(continued)

Watts Bar -Unit 2(developmental)

B 3.4-86AH I RCS Specific ActivityB 3.4.16BASESACTIONS B.1 and B.2(continued)

With the gross specific activity in excess of the allowed limit, an analysismust be performed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to determine DOSE EQUIVALENT 1-131. The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is required to obtain and analyzea sample.The change within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to MODE 3 and RCS average temperature

< 500OF lowers the saturation pressure of the reactor coolant below thesetpoints of the main steam safety valves and prevents venting the SG tothe environment in an SGTR event. The allowed Completion Time of6 hours is reasonable, based on operating experience, to reach MODE 3below 500OF from full power conditions in an orderly manner and withoutchallenging plant systems.C.1If a Required Action and the associated Completion Time of Condition Ais not met or if the DOSE EQUIVALENT 1-131 is greater than 24-14 pCi/gm, the reactor must be brought to MODE 3 with RCS averagetemperature

< 500OF within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> isreasonable, based on operating experience, to reach MODE 3 below500OF from full power conditions in an orderly manner and withoutchallenging plant systems.SURVEILLANCE SR 3.4.16.1REQUIREMENTS SR 3.4.16.1 requires performing a gamma isotopic analysis as a measureof the gross specific activity of the reactor coolant at least once every7 days. While basically a quantitative measure of radionuclides with halflives longer than 15 minutes, excluding

iodines, this measurement is thesum of the degassed gamma activities and the gaseous gamma activities in the sample taken. This Surveillance provides an indication of anyincrease in gross specific activity.

Trending the results of this Surveillance allows proper remedial action tobe taken before reaching the LCO limit under normal operating conditions.

The Surveillance is applicable in MODES 1 and 2, and inMODE 3 with Tavg at least 5000F. The 7-day Frequency considers theunlikelihood of a gross fuel failure during the time.(continued)

Watts Bar -Unit 2 B 3.4-87(developmental)

AHI Containment B 3.6.1BASESAPPLICABLE Satisfactory leakage rate test results are a requirement for theSAFETY establishment of containment OPERABILITY.

ANALYSES(continued)

The containment satisfies Criterion 3 of the NRC Policy Statement.

LCO Containment OPERABILITY is maintained by limiting leakage to < 1.0 La,except prior to the first start up after performing a required Containment Leakage Rate Testing Program leakage test. At this time, applicable leakage limits must be met.Compliance with this LCO will ensure a containment configuration, including equipment

hatches, that is structurally sound and that will limitleakage to those leakage rates assumed in the safety analysis.

Individual leakage rates specified for the containment air lock(LCO 3.6.2), purge valves with resilient seals, and Shield Buildingcontainment bypass leakage (LCO 3.6.3) are not specifically part of theacceptance criteria of 10 CFR 50, Appendix J, Option B. Therefore, leakage rates exceeding these individual limits only result in thecontainment being inoperable when the leakage results in exceeding theacceptance criteria of Appendix J, Option B.APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material into containment.

In MODES 5 and 6, the probability andconsequences of these events are reduced due to the pressure andtemperature limitations of these MODES. Therefore, containment is notrequired to be OPERABLE in MODES 5 and 6 to prevent leakage ofradioactive material from containment.

The requiremonts for cont4a!nmnt during MODE= 6 are addroso;-d-

'A LCO- 3.9.41, Contann ontrationu (continued)

Watts Bar -Unit 2(developmental)

B 3.6-3AH Containment Air LocksB 3.6.2BASES (continued)

APPLICABLE SAFETYANALYSESThe DBAs that result in a significant release of radioactive material withincontainment are a loss of coolant accident and a rod ejection accident(Ref. 2). In the analysis of each of these accidents, it is assumed thatcontainment is OPERABLE such that release of fission products to theenvironment is controlled by the rate of containment leakage.

Thecontainment was designed with an allowable leakage rate (La) of 0.25%of containment air weight per day (Ref. 2), at the calculated peakcontainment pressure of 15.0 psig. This allowable leakage rate forms thebasis for the acceptance criteria imposed on the SRs associated with theair locks.The containment air locks satisfy Criterion 3 of the NRC PolicyStatement.

LCOEach containment air lock forms part of the containment pressureboundary.

As part of containment pressure

boundary, the air lock safetyfunction is related to control of the containment leakage rate resulting from a DBA. Thus, each air lock's structural integrity and leak tightness are essential to the successful mitigation of such an event.Each air lock is required to be OPERABLE.

For the air lock to beconsidered

OPERABLE, the air lock interlock mechanism must beOPERABLE, the air lock must be in compliance with the Type B air lockleakage test, and both air lock doors must be OPERABLE.

The interlock allows only one air lock door of an air lock to be opened at one time. Thisprovision ensures that a gross breach of containment does not exist whencontainment is required to be OPERABLE.

Closure of a single door ineach air lock is sufficient to provide a leak tight barrier following postulated events. Nevertheless, both doors are kept closed when the airlock is not being used for normal entry into and exit from containment.

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment.

In MODES 5 and 6, the probability andconsequences of these events are reduced due to the pressure andtemperature limitations of these MODES. Therefore, the containment airlocks are not required in MODES 5 and 6 to prevent leakage ofradioactive material from containment.

The roquiromnts for the air locks .iunq MGOFDE 6 aro addr ,sed in 3.0.1,"Containment PenetrRtW0ns."

(continued)

Watts Bar -Unit 2(developmental)

B 3.6-7AH Containment Isolation ValvesB 3.6.3BASES (continued)

APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment.

In MODES 5 and 6, the probability andconsequences of these events are reduced due to the pressure andtemperature limitations of these MODES. Therefore, the containment isolation valves are not required to be OPERABLE in MODES 5 and 6.-The requireme~nts for contaiAnment isolation valVe6 during MODE 6 areaddrocod in LCOQ 3.9.4, Ponotration,"

ACTIONS The ACTIONS are modified by a Note allowing penetration flow paths, tobe unisolated intermittently under administrative controls.

Theseadministrative controls consist of stationing a dedicated operator(licensed or unlicensed) at the valve controls, who is in continuous communication with the control room. In this way, the penetration can berapidly isolated when a need for containment isolation is indicated.

Forvalve controls located in the control room, an operator (other than theShift Operations Supervisor (SOS), ASOS, or the Operator at theControls) may monitor containment isolation signal status rather than bestationed at the valve controls.

Other secondary responsibilities which donot prevent adequate monitoring of containment isolation signal statusmay be performed by the operator provided his/her primary responsibility is rapid isolation of the penetration when needed for containment isolation.

Use of the Unit Control Room Operator (CRO) to perform thisfunction should be limited to those situations where no other operator isavailable.

A second Note has been added to provide clarification that, for this LCO,separate Condition entry is allowed for each penetration flow path. Thisis acceptable, since the Required Actions for each Condition provideappropriate compensatory actions for each inoperable containment isolation valve. Complying with the Required Actions may allow forcontinued operation, and subsequent inoperable containment isolation valves are governed by subsequent Condition entry and application ofassociated Required Actions.The ACTIONS are further modified by third Note, which ensuresappropriate remedial actions are taken, if necessary, if the affectedsystems are rendered inoperable by an inoperable containment isolation valve.In the event the isolation valve leakage results in exceeding the overallcontainment leakage rate, Note 4 directs entry into the applicable Conditions and Required Actions of LCO 3.6.1.(continued)

Watts Bar -Unit 2 B 3.6-16(developmental)

AH HMSB 3.6.8BASESBACKGROUND (continued)

When the HMS is initiated, the ignitor elements are energized and heatup to a surface temperature

_ 1700'F. At this temperature, they ignite thehydrogen gas that is present in the airspace in the vicinity of the ignitor.The HMS depends on the dispersed location of the ignitors so that localpockets of hydrogen at increased concentrations would burn beforereaching a hydrogen concentration significantly higher than the lowerflammability limit. Hydrogen ignition in the vicinity of the ignitors isassumed to occur when the local hydrogen concentration reaches aminimum 5.0 volume percent (v/o).APPLICABLE SAFETYANALYSESThe HMS causes hydrogen in containment to burn in a controlled manneras it accumulates following a degraded core accident (Ref. 3). Burningoccurs at the lower flammability concentration, where the resulting temperatures and pressures are relatively benign. Without the system,hydrogen could build up to higher concentrations that could result in aviolent reaction if ignited by a random ignition source after such a buildup.The hydrogen ignitors are not included for mitigation of a Design BasisAccident (DBA) because an amount of hydrogen equivalent to thatgenerated from the reaction of 75% of the fuel cladding with water is far inexcess of the hydrogen calculated for the limiting DBA loss of coolantaccident (LOCA). The hydrgon .onc..-entr.ation ro..ulting from a DBA cAnbeA M.Atainta-nd 18-66 thRAn the- flamFmab9ility "imit ucin*g the hydrogerocombinorc.

The hydrogen ignitors.,hewe.'e-',

have been shown byprobabilistic risk analysis to be a significant contributor to limiting theseverity of accident sequences that are commonly found to dominate riskfor plants with ice condenser containments.

As such, the hydrogenignitors are considered to be risk significant in accordance with the NRCPolicy Statement.

(continued)

Watts Bar -Unit 2(developmental)

B 3.6-43AH Divider Barrier Integrity B 3.6.13BASESSURVEILLANCE REQUIREMENTS (continued)

SR 3.6.13.3Verification, by visual inspection, after each opening of a personnel access door or equipment hatch that it has been closed makes theoperator aware of the importance of closing it and thereby providesadditional assurance that divider barrier integrity is maintained while inapplicable MODES.SR 3.6.13.4Not used.The di-ider barrior o6al can be field 6pliced for ropa!r purposesutilizing a cold bond procedure rather than the original field Gplice-technique of vulcanization.

However, the cod bond adhesive, whichworks in conjunc~tion with a bolt array to splice the field joint, cOulId not beheat aged te 40 years plaRt life pFr6r to ac,-ptability testing.

expesure te the elevaotehd tempeFatutres required foF heat aging the sA'emateria-l w.as destructive to the adhesive.

The seal mnaterial war, heataged to 40 years equivalent ago, and the entire joint assembly war,irFradi~ated-to- 10 year nrmFRal operation plus accident integrated doese-,Conducting periodic peel tests On the test specimensR provides assuranca that the ad-hesive has net degraded in the containmen-.t environmAFent.

Thejjoint ,followed dby y1 8month sfthe pepeo llength his sgreate rtha n14' "and36 6month si fthe Pepee llengthi sless tha nor requal lt o12" ir sbased duponthe eorigina lvendor's srecommendatio nwhichi s6base dupo nbaselineexAa minaRtio1 no fthe estre ngth o fthe eadhesive.

Therefore

,the eF requ encywa: -scon c ud e dtn ob enAsco t abI of rom a; r eAliahdbili t y tndnn int.vSR 3.6.13.5Visual inspection of the seal around the perimeter provides assurance that the seal is properly secured in place. The Frequency of 18 monthswas developed considering such factors as the inaccessibility of the sealsand absence of traffic in their vicinity, the strength of the bolts andmechanisms used to secure the seal, and the plant conditions needed toperform the SR. Operating experience has shown that these components usually pass the Surveillance when performed at the 18 monthFrequency.

Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.

REFERENCES 1 .Wafts Bar FSAR, Section 6.2, "Containment Systems."

Watts Bar -Unit 2(developmental)

B 3.6-83AH CCSB 3.7.7B 3.7 PLANT SYSTEMSB 3.7.7 Component Cooling System (CCS)BASESBACKGROUND The CCS provides a heat sink for the removal of process and operating heat from safety related components during a Design Basis Accident(DBA) or transient.

During normal operation, the CCS also provides thisfunction for various non-essential components, as well as the spent fuelstorage pool. The CCS serves as a barrier to the release of radioactive byproducts between potentially radioactive systems and the Essential Raw Cooling Water (ERCW) System, and thus to the environment.

The CCS is arranged as two independent, full-capacity cooling trains,Train A and Train B. Train A in Unit 2 is served by CCS Hx B andCCS pump 2A-A. Pump 2B-B, which is actually Train B equipment, isalso normally aligned to the Train A header in Unit 2. However,pump 2B-B can be realigned to Train B on loss of Train A.Train B is served by CCS Hx C. Normally, only CCS pump C-S is alignedto the Train B header since few non-essential, normally-operating loadsare assigned to Train B. However, pump 2B-B can be realigned to theTrain B header on a loss of the C-S pump.Each safety related train is powered from a separate bus. An open surgetank in the system provides pump trip protective functions to ensure thatsufficient net positive suction head is available.

The pump in each train isautomatically started on receipt of a safety injection signal, and allnon-essential components will be manually isolated.

CCS Pump 1B-B may be substituted for CCS Pump C-S supplying the Unit 2 CCS Train B header provided the OPERABILITY requirements are met.Additional information on the design and operation of the system, alongwith a list of the components served, is presented in the FSAR,Section 9.2.2 (Ref. 1). The principal safety related function of the CCS isthe removal of decay heat from the reactor via the Residual HeatRemoval (RHR) System. This may be during a normal or post accidentcooldown and shutdown.

(continued)

Watts Bar -Unit 2 B 3.7-36(developmental)

GHI CCSB 3.7.7BASESLCO(continued)

c. If CCS Pump 11B-B is substituted for CCS Pump C-S supplying the Unit 2 CCS Train B header, CCS Pump IB-B is onlyconsidered OPERABLE when aligned to the CCS Train B headerand operating.

The isolation of CCS from other components or systems not required forsafety may render those components or systems inoperable but does notaffect the OPERABILITY of the CCS.CCS Pump 1B-B only receives a safety injection (SI) signal fromUnit 1. If CCS Pump I B-B is in a standby mode and is aligned as asubstitute for CCS Pump C-S, then Unit 2 CCS train B will not beoperable.

Conversely, if CCS Pump 1B-B is operating and alignedas a substitute for CCS Pump C-S supplying the CCS Train Bheader, then Unit 2 CCS Train B is OPERABLE.

The presence of anSI signal in Unit 2 will have no effect on CCS Pump 1B-B and thepump will continue to operate.

In the event of a loss of offsitepower, with or without an SI signal present, CCS Pump I B-B will beautomatically sequenced onto its respective diesel and continue toperform its required safety function.

APPLICABILITY In MODES 1, 2, 3, and 4, the CCS is a normally operating system, whichmust be prepared to perform its post accident safety functions, primarily RCS heat removal, which is achieved by cooling the RHR heatexchanger.

In MODE 5 or 6, the OPERABILITY requirements of the CCS aredetermined by the systems it supports.

(continued)

Watts Bar -Unit 2(developmental)

B 3.7-38AH I CCSB 3.7.7BASESSURVEILLANCE REQUIREMENTS (continued)

S R 3.7.7.4This SR verifies proper automatic operation of the CCS pumps on anactual or simulated actuation signal. The CCS is a normally operating system that cannot be fully actuated as part of routine testing duringnormal operation.

The 18 month Frequency is based on the need toperform this Surveillance under the conditions that apply during a unitoutage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience hasshown that these components usually pass the Surveillance whenperformed at the 18 month Frequency.

Therefore, the Frequency isacceptable from a reliability standpoint.

This SR does not apply to CCS Pump 1B-B when substituted forCCS Pump C-S to establish operability of Unit 2 CCS Train B. CCSPump 1B-B does not receive an SI actuation signal from Unit 2. If itis operating and aligned as a substitute for CCS Pump C-Ssupplying the CCS Train B header, the presence of an SI signal inUnit 2 will have no effect on CCS Pump 1B-B and the pump willcontinue to perform its required safety function.

In the event of aloss of offsite power, with or without an SI signal present, CCSPump 1B-B will be automatically sequenced onto its respective diesel and continue to perform its required safety function.

SR 3.7.7.5This SR assures the operability of Unit 2 CCS Train B when CCSPump I B-B is substituted for CCS Pump C-S. Since CCS Pump I B-Bdoes not receive an Sl actuation signal from Unit 2, by verifying thepump is aligned and operating, assurance is provided that Unit 2CCS Train B will be operable in the event of a Unit 2 SI actuation.

REFERENCES

1. Watts Bar FSAR, Section 9.2.2, "Component Cooling System."2. Watts Bar Component Cooling System Description, N3-70-4002.

Watts Bar -Unit 2(developmental)

B 3.741AH I ABGTSB 3.7.12B 3.7 PLANT SYSTEMSB 3.7.12 Auxiliary Building Gas Treatment System (ABGTS)BASESBACKGROUND The ABGTS filters airborne radioactive particulates from the area of thefuel following a fuel handling aRd from the area of activeUnit 2 ECCS components and Unit 2 penetration rooms following a lossof coolant accident (LOCA).The ABGTS consists of two independent and redundant trains. Eachtrain consists of a heater, a prefilter, moisture separator, a high efficiency particulate air (HEPA) filter, two activated charcoal adsorber sections forremoval of gaseous activity (principally iodines),

and a fan. Ductwork, valves or dampers, and instrumentation also form part of the system.A second bank of HEPA filters follows the adsorber section to collectcarbon fines and provide backup in case the main HEPA filter bank fails.The downstream HEPA filter is not credited in the analysis.

The systeminitiates filtered ventilation of the Auxiliary Building Secondary Containment Enclosure (ABSCE) exhaust air following receipt of aPhase A containment isolation signal or a high radiatienR Gigal from, thespent fuel pool area.The ABGTS is a standby system, not used during normal plantoperations.

During emergency operations, the ABSCE dampers arerealigned and ABGTS fans are started to begin filtration.

Air is exhausted from the Unit 2 ECCS pump rooms, Unit 2 penetration rooms, and fuelhandling area through the filter trains. The prefilters or moistureseparators remove any large particles in the air, and any entrained waterdroplets

present, to prevent excessive loading of the HEPA filters andcharcoal adsorbers.

The plant design basis requirFeS that when movinRg irradiated fuel in theAuxiliar; Building and/or Containment With the Containment open to theAui~~ Buildingq A:39GE SpG a signal fQAthe Gpem fW8uu90radi-ation moritorm 0 RE 90 102 and 103 Will initiate a C-otainment Ventilatior n Isolation (VI) in addition to their rnormnl funcrtin.

In addition, a 6ignal froEm the cnAtaiFnment purge radc-iafionmnior I RE 90 130 and131 or othr VI signal " 11 initiate that po.tion of the ABI normal*lnitiated by the spent fuel poo0 radiation monitors..

Additionally, aContah."inmentIolation Phase A (SI -igRal) from the operatiRg unit, hightemper~ature in the Auxiliary Building air intakes, or manual AB!(continued)

Watts Bar -Unit 2(developmental)

B 3.7-63GH ABGTSB 3.7.12BASESBACKGROUND (continued)

.:viw cas a ivi w anaui inl inl meu cas vwnre incvB J tl wAt Jl.J~ fl11 7Ifl~ TV U~~fl T~rTYfl~

TtJ ~~tJT I flJ fl T~ I ~LIflflILfl 3 ~IAIThAII

~ -Vin nerie nit will initiitn CVI in the ether ,-nit ineorder to maintain thoeevvinrumentato mAut remnain operable when moeving i~rradiated fuel in theA uxiliar" Building if the containment air locGks,penetrations, equipment hatch, etc. arc open to the Auxiliary Buildin~g BSCE9 spacaes.

In addlitio, the ABGTS mu-st remain operable if thesecOntainment penotratipoc arc eoon to the Auxiliary Building durina-vnt # -n n f ;-,,4;-+

.f..r 1 ;n ; 14;A +n~ ;, +~n--" J ........

0 ......V'rar"Orl 01 01- -0 r1a a t7wrl cz rimorl .The ABGTS is discussed in the FSAR, Sections 6.5.1, 9.4.2, 15.0, and6.2.3 (Refs. 1, 2, 3, and 4, respectively).

APPLICABLE SAFETYANALYSESThe ABGTS design basis is established by the consequences of thelimiting Design Basis Accident (DBA), which is a LOCA. fue[Iamdllf§

.,n,.,,4nn TI', aa nl'16*6c

-S thA .,Ihn-h 'A'n~rnn Nintan =GanQ#CiVRI II IThe analysis of the LOCA assumes that radioactive materials leaked fromthe Emergency Core Cooling System (ECCS) are filtered and adsorbedby the ABGTS. The DBA analysis of the fuel handling accident assumesthat only one train of the ABGTS is functional due to a single failure thatdisables the other train. The accident analysis accounts for the reduction in airborne radioactive material provided by the one remaining train of thisfiltration system. The amount of fission products available for releasefrom the ABSCE is determined for a fue! handfIng accident and for aLOCA. The assumption.. ... 4 ad .analySiS forF a4 fu-el handli-ng accidentfelloW the guidance proVided in Regulatory Guide 1.25 (Ref. 5) andNUREG/CR 5009 (Ref. 10). The assumptions and analysis for a LOCAfollow the guidance provided in Regulatory Guide 1.4 (Ref. 65).The ABGTS satisfies Criterion 3 of the NRC Policy Statement.

tiDIBuilding withl containmen~t air locks Or penetrations open to theo Auxiliary Building ABSCE spaceS, Or when moving fuel in the Auxiliary Buildingw:ith the con~tainment equipm~ent hatch open, the proVisions to9ntit aC-VI from. the rpent fulpelrdation monRitors and to initiate ain A.-Iki.u., Me Pertien 9+ an :Aoi normally Munatee Sy fme 6ponmi+U9!peefi r-adiation moenitors6) from a CVI, including a CVI initiated by thecontainment purge monitors, in the event of a fue! handling accident(FH1A) must be in place and functeionig.

Additionally, a Containment Isolation Phase A (SI Sign~a!)

from the oer~eat*R1 unit, higlh(continued)

Watts Bar -Unit 2(developmental)

B 3.7-64GH ABGTSB 3.7.12BASESAPPLICABLE SAFETYANALYSES(continued) temnperature lin the- Aux;Ilinay Building air intake,,

Or manual ABI Will causoa CVI 6igna! in tho refueling unit. The centainmonRt equipment hatchcannoet be open When moGVing irradiated fuel inside containmen~t inaccordance with Specifcatieon 3.9.4.The ABGT-S i6 required to be opeFable during movement of irradiated fuelin the Auxiliay Buwilding during any and during moveent ofRiRradiated fuel in ReRa;ctor Builing when the RAciltor Building isestablirhed as pan t of the ABSCE boundary (seo T-S 3.3.8, 3.7.12, &3.0.4). When ming"irra*dated fuel inside containment, at least one trainof the onmtaimetpug system mnust be operating Or the containmenAt mAust be isolated. l moeving irradiated fuel in the Auxiliary Buildingduý,ng timne wheRn the is olpen to the Auxiliary BuildirgABSGE6pa~6containment PU~ a eoperated, btoperatieRon hsystemR 06 not required.

However, whether.

the containmenRt purge systemAis6 operated o-r- not in this; confguration, all containmenRt Ventilatiniolato valves and associated isrmnaonmust remnain operable.

Tirequirement is cesr to ensure a CVI can be accomAplished "FRo thespent fuel peel ra-d-;ia~tion moni-R..to-rs-in. the event of a F-H.A in the Auxiliary Building.

Additionally, a Containment Isolation Phase A (SI signal) framthe operating unit, high temnperature in the Auxiliar-y B3uilding air intakes,Or mnanual ABI 4.0ll cause a CVI cigna! in the refueling unit. In the casewhere the containment of both units is open to the Auxiliary BuldingF~

spaces, a CVI in one unit will initiate a CVI in the ether unit in order tomaintain these spaces open to the ABSCE.LCOTwo independent and redundant trains of the ABGTS are required to beOPERABLE to ensure that at least one train is available, assuming asingle failure that disables the other train, coincident with a loss of offsitepower. Total system failure could result in the atmospheric release fromthe ABSCE exceeding the 10 CFR 100 (Ref. 7-6) limits in the event of afuel handling accident or LOCA.The ABGTS is considered OPERABLE when the individual components necessary to control exposure in the fiel haii'ii-bAuxiliary Building areOPERABLE in both trains. An ABGTS train is considered OPERABLEwhen its associated:

a. Fan is OPERABLE;
b. HEPA filter and charcoal adsorber are not excessively restricting flow, and are capable of performing their filtration function; and(continued)

Watts Bar -Unit 2(developmental)

B 3.7-65GH ABGTSB 3.7.12BASESLCO(continued)

c. Heater, moisture separator,
ductwork, valves, and dampers areOPERABLE, and air circulation can be maintained.

APPLICABILITY In MODE 1, 2, 3, or 4, the ABGTS is required to be OPERABLE toprovide fission product removal associated with ECCS leaks due to aLOCA and leakage from containment and annulus.In MODE 5 or 6, the ABGTS is not required to be OPERABLE since theECCS is not required to be OPERABLE.

During mo'-ement of irradiatod fudel in the fue! handling area, the ABGTS8 is roquirod to be QPE=RARLP toalleviate the cOnceqIUoncoc of a fuel handling accident.

See additienal d*iGc3uccF~oQ in tho Backoron-d

nd Aen'*Rable Safot'
AnaIV6ic GoctioncACTIONSA._1With one ABGTS train inoperable, action must be taken to restoreOPERABLE status within 7 days. During this period, the remaining OPERABLE train is adequate to perform the ABGTS function.

The 7-dayCompletion Time is based on the risk from an event occurring requiring the inoperable ABGTS train, and the remaining ABGTS train providing therequired protection.

B.1 and B.2IR MODE 1, 2, 3, or 1, wWhen Required Action A.1 cannot be completed within the associated Completion Time, or when both ABGTS trains areinoperable, the plant must be placed in a MODE in which the LCO doesnot apply. To achieve this status, the plant must be placed in MODE 3within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The Completion Timesare reasonable, based on operating experience, to reach the requiredplant conditions from full power conditions in an orderly manner andwithout challenging plant systems.(continued)

Watts Bar -Unit 2(developmental)

B 3.7-66AH ABGTSB 3.7.12BASESAGTQNS(Ge~tRued)

%AA, 0 ; A A *. A 4 + k I + A ;+k; +k ; 14a" atla rv tPri .UmMi" 0 wcrmp CP w r_1 W ruga r%7GGFAPI8ti9R T4AB, GIWOR9 FRevement of iFFadiated fuel ;;rsAmhI;A OR thefUel haRdIiR9 aFea, the OPPRARI F= AI3GT_9 tFaiR must be staFtimmediately ear fuel rneyeMeAt 6UspeRded.

This aGtiGA eA661F86 that theFeFna6A4A@

tr-ROR is GO PERABLE, that Re URElete6ted faWUFe6 PFeYeAtiR@

ation %kill eAr_,UF, aRd that aRy acAiye fail mw*ll he re dilyif the system is not plaGed iR epeFatien, thir, aGtiG 6PeF16i9R 9ffUel FnGY8Fn6At, WhiGh pFeGludes a fue-I an-roid-ent.

T4;' FeGludethe FneyemeRt ef fuel assemblies te a 6afe P96iti9R.

9.4VVh8R tWO tFaiRG of the ABGT-S aFe 'RepeFable du Rk4_* Ffad*ated fuel assemblies in the fuel handliRg aFea-, ýansfieen immust be takeRte E)Iaee the URit iR a GgRditiw; iR WhiGh the I=GG de96 not apply. A.0ionAm I I I I Emarsembfies

  • R the fuel na Thrs does A9t PF9Glude tFR9Y9FneAt 9f A-19-1 t9 a GialeSURVEILLANCE REQUIREMENTS SR 3.7.12.1.

Standby systems should be checked periodically to ensure that theyfunction properly.

As the environmental and normal operating conditions on this system are not severe, testing each train once every monthprovides an adequate check on this system.Monthly heater operation dries out any moisture accumulated in thecharcoal from humidity in the ambient air. The system must be operatedfor ý! 10 continuous hours with the heaters energized.

The 31 -dayFrequency is based on the known reliability of the equipment and thetwo train redundancy available.

(continued)

Wafts Bar -Unit 2(developmental)

B 3.7-67AH ABGTSB 3.7.12BASESSURVEILLANCE REQUIREMENTS (continued)

SR 3.7.12.2This SR verifies that the required ABGTS testing is performed inaccordance with the Ventilation Filter Testing Program (VFTP). TheABGTS filter tests are in accordance with Regulatory Guide 1.52 (Ref. 8).The VFTP includes testing HEPA filter performance, charcoal adsorberefficiency, minimum system flow rate, and the physical properties of theactivated charcoal (general use and following specific operations).

Specific test frequencies and additional information are discussed indetail in the VFTP.SR 3.7.12.3This SR verifies that each ABGTS train starts and operates on an actualor simulated actuation signal. The 18-month Frequency is consistent withReference 87.SR 3.7.12.4This SR verifies the integrity of the ABSCE. The ability of the ABSCE tomaintain negative pressure with respect to potentially uncontaminated adjacent areas is periodically tested to verify proper function of theABGTS. During the post accident mode of operation, the ABGTS isdesigned to maintain a slight negative pressure in the ABSCE, to preventunfiltered LEAKAGE.

The ABGTS is designed to maintain a negativepressure between -0.25 inches water gauge and -0.5 inches water gauge(value does not account for instrument error) with respect to atmospheric pressure at a nominal flow rate > 9300 cfm and < 9900 cfm. TheFrequency of 18 months is consistent with the guidance provided inNUREG-0800, Section 6.5.1 (Ref. 98).An 18-month Frequency (on a STAGGERED TEST BASIS) is consistent with Reference 87.REFERENCES

1. Watts Bar FSAR, Section 6.5.1, "Engineered Safety Feature (ESF)Filter Systems."
2. Watts Bar FSAR, Section 9.4.2, "Fuel Handling Area Ventilation System."3. Watts Bar FSAR, Section 15.0, "Accident Analysis."

(continued)

Watts Bar -Unit 2(developmental)

B 3.7-68SH ABGTSB 3.7.12BASESREFERENCES (continued)

4. Watts Bar FSAR, Section 6.2.3, "Secondary Containment Functional Design."5-, Rogulatory Guido 1.25, Mach 197-2, "A ,.umptien Uso-,d forFiyalwatkng tho Potentilal Radielogical Consoquoncoc of a FuolNAMOilnn

-- M WRR, uIAZoA 40a;ter 14AtRAc.65. Regulatory Guide 1.4, "Assumptions Used for Evaluating thePotential Radiological Consequences of a Loss of Coolant Accidentfor Pressurized Water Reactors."

-76. Title 10, Code of Federal Regulations, Part 100.11, "Determination of Exclusion Area, Low Population Zone, and Population CenterDistance."

87. Regulatory Guide 1.52 (Rev. 2), "Design, Testing and Maintenance Criteria for Post Accident Engineered-Safety-Feature Atmospheric Cleanup System Air Filtration and Adsorption Units of Light-Water Cooled Nuclear Power Plants."98. NUREG-0800, Section 6.5.1, "Standard Review Plan," Rev. 2, "ESFAtmosphere Cleanup System,"

July 1981.I4-0-F dm I i B PNUL-IGt.G Water, -c'-e MoAn ottri, U.o S? NLear neg lIuAnupFuel in Liaht W~ator PoW8r Reactors."

UJ. S. Nuclear ReaulatoR' 60mmiSc9ion.

1-orur':mm.

Watts Bar -Unit 2(developmental)

B 3.7-69BH Fuel Storage Pool Water LevelB 3.7.13B 3.7 PLANT SYSTEMSB 3.7.13 Fuel Storage Pool Water LevelBASESBACKGROUND The minimum water level in the fuel storage pool meets the assumptions of iodine decontamination factors following a fuel handling accident.

Thespecified water level shields and minimizes the general area dose whenthe storage racks are filled to their maximum capacity.

The water alsoprovides shielding during the movement of spent fuel.A general description of the fuel storage pool design is given in the FSAR,Section 9.1.2 (Ref. 1). A description of the Spent Fuel Pool Cooling andCleanup System is given in the FSAR, Section 9.1.3 (Ref. 2). Theassumptions of the fuel handling accident are given in the FSAR,Section 4 4 515.5.6 (Ref. 3).APPLICABLE SAFETYANALYSESThe minimum water level in the fuel storage pool meets the assumptions of the fuel handling accident described in Regulatory Guide 1.26(Ref.4)1.183 (Ref. 4.) The Total Effective Dose Equivalent (TEDE) forcontrol room occupants, individuals at the exclusion area boundary, and individuals within the low population zone will remain within10 CFR 50.67 (Ref. 5) and Regulatory Position C.4.4 of Regulatory Guide 1.183 for a fuel handling accident.

The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> thyroiddseo per pernsR at the ourv*ohn area is a small fractin Of the10 CFR 100 (Ref. 5) limits.According to Reference 43, there is 23 ft of water between the top of thedamaged fuel bundle and the fuel pool surface during a fuel handlingaccident.

With 23 ft of water, the assumptions of Reference 4 can beused directly.

In practice, this LCO preserves this assumption for the bulkof the fuel in the storage racks. In the case of a single bundle droppedand lying horizontally on top of the spent fuel racks; however, there maybe < 23 ft of water above the top of the fuel bundle and the surface,indicated by the width of the bundle. To offset this smallnon-conservatism, the analysis assumes that all fuel rods fail, althoughanalysis shows that only the first few rows fail from a hypothetical maximum drop.The fuel storage pool water level satisfies Criterion 2 of the NRC PolicyStatement.

(continued)

Watts Bar -Unit 2(developmental)

B 3.7-68AH Fuel Storage Pool Water LevelB 3.7.13BASES (continued)

REFERENCES

1. Watts Bar FSAR, Section 9.1.2, "Spent Fuel Storage."
2. Watts Bar FSAR, Section 9.1.3, "Spent Fuel Pool Cooling andCleanup System."3. Watts Bar FSAR, Section 5.4 , "Fuel Handling Accident."
4. Regulatory Guide 1.25, March 1072, "Assumptions Used forEg'alwat6ng the Potentfial Radiological Gonsogueonces of a Fuel AccideRt iR the Fuel Handling and Storage Facility forBOiling and Pressurized Wat- r Roactors."Regulatory Guide 1.183,"Alternate Source Terms for Evaluation Design BasisAccidents at Nuclear Power Reactors",

July 2000.5. Title 10, Code of Federa! Regulations, Part 100. 11, "Determninatio of Exclu6ion Area, Low Population Zone, and Popu-lation C-enterQDta~e-!Title 10, Code of Federal Regulations, 10 CFR 50.67,"Accident Source Term."Watts Bar -Unit 2(developmental)

B 3.7-70AH Spent Fuel Assembly StorageB 3.7.15B 3.7 PLANT SYSTEMSB 3.7.15 Spent Fuel Assembly StorageBASESBACKGROUND The spent fuel pool contains flux trap rack modules with 1386 storagepositions and that are designed to accommodate new fuel with amaximum enrichment of 4.95 + 0.05 weight percent U-235 and fuel ofvarious initial enrichments when stored in accordance withparagraph 4.3.1.1 in Section 4.3, Fuel Storage.as high a63.8 Weight percen~t UJ 235 withut restrictions.

Storago of fuel assemblies w.,ith enric;hFment beo 3.. 3.8 and 5.0 weight percent requires "ithor fuelburnup in accordance With paragraph 4.3.1.1 or placement in .toragelocations which have face adjacent storage coils coentaining either watero~r fuel Rrassoblioc with accum~ulated bUFrup of at least 20.0 MWDI~gU inaccordance with Spocification 4.3.1.1.The water in the spent fuel storage pool normally contains soluble boron,which results in large subcriticality margins under actual operating conditions.

However, the NRC guidelines, based upon the accidentcondition in which all soluble poison is assumed to have been lost,specify that the limiting keff of 0.95 be evaluated in the absence of solubleboron. Hence, the design is based on the use of unborated water, whichmaintains the storage racks in a subcritical condition during normaloperation with the racks fully loaded. The double contingency principle discussed in ANSI N-16.1-1975, and the April 1978 NRC letter(Reference
1) allows credit for soluble boron under other abnormal oraccident conditions, since only a single accident need be considered atone time. For example, an abnormal scenario could be associated withthe improper loading of a relatively high enrichment, low exposure fuelassembly.

This could potentially increase the criticality of the storageracks. To mitigate these postulated criticality-related events, boron isdissolved in the pool water. Safe operation of the spent fuel storagedesign with no movement of assemblies may therefore be achieved bycontrolling the location of each assembly in accordance with theaccompanying LCO. Prior to movement of an assembly in the pool, it isnecessary to perform SR 3.9.9.1.(continued)

Watts Bar -Unit 2(developmental)

B 3.7-76AH I DC Sources -Operating B 3.8.4BASESBACKGROUND 125 V Vital DC Electrical Power Subsystem (continued)

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

Each of the vital DC electrical power subsystems provides the controlpower for its associated Class 1 E AC power load group, 6.9 kVswitchgear, and 480 V load centers.

The vital DC electrical powersubsystems also provide DC electrical power to the inverters, which inturn power the AC vital buses. Additionally, they power the emergency DC lighting system.The vital DC power distribution system is described in more detail inBases for LCO 3.8.9, "Distribution System -Operating,"

and LCO 3.8.10,"Distribution Systems -Shutdown."

Each vital battery has adequate storage capacity to carry the requiredload continuously 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 ACpower (station blackout) without an accident or for 30 minutes with anaccident considering a single failure.

Load shedding of non-required loads will be performed to achieve the required coping duration for stationblackout conditions.

Each 125 VDC vital battery is separately housed in a ventilated roomapart from its charger and distribution

centers, except for Vital Battery V.Each subsystem is located in an area separated physically andelectrically from the other subsystem to ensure that a single failure in onesubsystem does not cause a failure in a redundant subsystem.

There isno sharing between redundant Class 1 E subsystems, such as batteries, battery chargers, or distribution panels.The batteries for the vital DC electrical power subsystems are sized toproduce required capacity at 80% of nameplate rating, corresponding towarranted capacity at end of life cycles, de-rated for minimum ambienttemperature and the 100% design demand. The voltage limit is 2.13 Vper coll, Which cOrreSPOnds to a total minimum voltage output of 128 Vper batt,';'

(132 V for Vital Battery, V). The criteria for sizing large leadstorage batteries are defined in IEEE-485 (Ref. 5).(continued)

Watts Bar -Unit 2 B 3.8-49(developmental)

AH DC Sources -Operating B 3.8.4BASESBACKGROUND 125 V Vital DC Electrical Power Subsystem (continued)

The battery cells are of flooded lead acid construction with anominal specific gravity of 1.215. This specific gravity corresponds to an open cell voltage of 2.07 Volts per cell (Vpc). For a 58 cellbattery (DG battery),

the total minimum output voltage is 120 V; for a60 cell battery (vital battery) the total minimum output voltage is124 V; and for a 62 cell battery (5th vital battery),

the total minimumoutput voltage is 128 V. The open circuit voltage is the voltagemaintained when there is no charging or discharging.

Once fullycharged, the battery cell will maintain approximately 97% of itscapacity for 30 days without further charging per manufacturer's instructions.

Optimal long term performance,

however, is obtainedby maintaining a float voltage from 2.20 to 2.25 Vpc. This providesadequate over-potential, which limits the formation of lead sulfateand self discharge.

Each Vital DC electrical power subsystem has ample power outputcapacity for the steady state operation of connected loads required duringnormal operation, while at the same time maintaining its battery bank fullycharged.

Each battery charger also has sufficient capacity to restore thebattery bank from the design minimum charge to its fully charged statewithin 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 minuteAC 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 /> (while supplying normalsteady 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 power outage),

(Ref. 6).The battery charger is normally in the float-charge mode. Float-charge is the condition in which the charger is supplying theconnected loads and the battery cells are receiving adequate currentto optimally charge the battery.

This assures the internal losses of abattery are overcome and the battery is maintained in a fullycharged state.When desired, the charger can be placed in the equalize mode. Theequalize mode is at a higher voltage than the float mode andcharging current is correspondingly higher. The battery charger isoperated in the equalize mode after a battery discharge or forroutine maintenance.

Following a battery discharge, the batteryrecharge characteristic accepts current at the current limit of thebattery charger (if the discharge was significant, e.g., following abattery service test) until the battery terminal voltage approaches the charger voltage setpoint.

Charging current then reducesexponentially during the remainder of the recharge cycle. Leadcalcium batteries have recharge efficiencies of greater than 91%, soonce at least 110% of the ampere-hours discharged have beenreturned, the battery capacity would be restored to the samecondition as it was prior to the discharge.

This can be monitored by(continued)

Watts Bar -Unit 2 B 3.8-50(developmental)

BH DC Sources -Operating B 3.8.4BASESdirect observation of the exponentially decaying charging current orby evaluating the amp-hours discharged from the battery and amp-hours returned to the battery.(continued)

Watts Bar -Unit 2(developmental)

B 3.8-51BH DC Sources -Operating B 3.8.4BASES (continued)

LCO Four 125V vital DC electrical power subsystems, each vital subsystem channel consisting of a battery bank, associated battery charger and thecorresponding control equipment and interconnecting cabling supplying power to the associated DC bus within the channel; and four DG DCelectrical power subsystems each consisting of a battery, a batterycharger, and the corresponding control equipment and interconnecting cabling are required to be OPERABLE to ensure the availability of therequired power to shut down the reactor and maintain it in a safecondition after an anticipated operational occurrence (AOO) or apostulated 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 threea Notes. T-he-Note 1 indicates that VitalBattery V may be substituted for any of the required vital batteries.

However, the fifth battery cannot be declared OPERABLE until it isconnected electrically in place of another battery and it has satisfied applicable Surveillance Requirements.

Note 2 indicate that spare vitalchargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vitalchargers.

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

However, thespare charger(s) cannot be declared OPERABLE until it isconnected electrically in place of another charger, and it hassatisfied applicable Surveillance Requirements.

APPLICABILITY The four vital DC electrical power sources and four DG DC electrical power sources are required to be OPERABLE in MODES 1, 2, 3, and 4 toensure safe plant 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 andother vital functions are maintained in the event of a postulated DBA.The DC electrical power requirements for MODES 5 and 6 are addressed in the Bases for LCO 3.8.5, "DC Sources -Shutdown."

(continued)

Watts Bar -Unit 2 B 3.8-53(developmental)

AH DC Sources -Operating B 3.8.4BASESA GTI ON A4/=% -- -- J:L;-- -- AI-OR41Atu

/A rO8epreS ent e vita! Gninnel WKHr a 1966 ef ability LUcomBpletely respond to an evont, and a potontial loss of ability to rmienRegized duFrig nrmF~a! operation.

Rt.i, therefore, imnperatiye that theoperator's attention focus_ on .tabiliin the plant, minimi~zingq the potential for comIplete loss of PG poworA- to the ff~ecGted train. Tho 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> limint iscncirstont With the All0owed time for. Rannprbe distributo systemIf one Of the roquirod vital DCG e-lectric4al poWor subs)ystwms is inoperable (e.g., inoperable batter,',

inoperable battory charger(s),

or inoperable battery charger and associated inoereable battery),

the remaining-vital DG electrical power subsystemA has the capacity to support a safeishutdow-nA an;d to mnitigate an accGident condition.

S~ince A su bsequentworst case single failure of the PERmA.BLE SUbsystem; would, however,resut i a ituation Where the ability of the 425V DG electricGal powersubsystem; te support its required ESF function is not assured, continued power eperatien sheuld not eXceed 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s6. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> COMPIAetiGn TimeAis based en Regulator',

Guide 1.93 (Ref. 8) and reflects a roasenable timneto assess plant status as a functioin-of the inopcrable vital DC electrical poere subsystemn and, if the vital DG electrical poWer subsystem is notrestorFed to OPERABLE status, to prepare to effect an orderly and safeif the inoper-able vita! DG electrical power sub6ystmOR cannot be restoredte OPERABLE status within the required Com~pletion Tim~e, the plant Mustbe brought to a MODE in whic-h the LCGO does net apply. To9 achieve thisstatus, the plant mnust be brought to at le-ast MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> andto MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are-reasonable, based on operating eXPerience, to reach the required plantcon-ditios fromR full power conditions i an orderly manner ;And Withou tchallenging plant systems.

The Comple~tionR T~i.m._e tobring the plant toMODE 5 is consistent With the timeA required in Regulatory Guide 1.93(Ref. 4.Condition C representG one DG with a losseof ability to completely-respond to an event. SincGe a subsequent single failure onR the eppesitetrain Gould result in a situation; wh~ere the required ESP function is netasSUred, con~tinued power o~peration should net e*ceed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The-2 hortime0 lim.it is consR.istent With the allowed tim:e forF an nprbl iaDG Beletrical power subsystem.

(GGRtined)

(continued)

Watts Bar -Unit 2(developmental)

B 3.8-54AH DC Sources -Operating B 3.8.4BASES94If tho DG DG Gnnot be restored toOPERA., 1LE status in the ascctatd Completion, Time, the a6sociatod DG May be incapable of pe~ferming it6 inended-funcAtion and must beimmediat.ly declared R+operable.

This d^+laration al- o require.

9,ntY intoapplicable ConRditions and Requirod Ac-tions Jfr -An ineporable DG, LCOQ3.8.1, "AG SourFGos Operating."

ACTIONS A.1. A.2, A.3. E.1. E.2. and E.3Conditions A and E represent one channel with one battery chargerinoperable (e.g., the voltage limit of SR 3.8.4.1 or SR 3.8.4.2 is notmaintained).

The ACTIONS provide a tiered response that focuseson returning the battery to the fully charged state and restoring afully qualified charger to OPERABLE status in a reasonable timeperiod. Required Actions A.1 and E.1 require that the batteryterminal 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 />. This time provides forreturning the inoperable charger to OPERABLE status or providing an alternate means of restoring battery terminal voltage to greaterthan or equal to the minimum established float voltage.

Restoring the battery terminal voltage to greater than or equal to the minimumestablished float voltage provides good assurance that, within12 hours, the battery will be restored to its recharged condition fromany discharge that might have occurred due to the chargerinoperability.

A discharged battery having terminal voltage of at least theminimum established float voltage indicates that the battery is onthe exponential charging current portion (the second part) of itsrecharge cycle. The time to return a battery to its fully charged stateunder 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 within12 hours, avoiding a premature shutdown with its own attendant risk.(continued)

(eentied)

Watts Bar -Unit 2 B 3.8-55(developmental)

AH DC Sources -Operating B 3.8.4BASESACTIONS A.1, A.2, A.3, E.1, E.2, and E.3 (continued)

If battery terminal float voltage cannot be restored to greater than orequal 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 />, andthe charger is not operating in the current-limiting mode, a faultycharger is indicated.

A faulty charger that is incapable ofmaintaining established battery terminal float voltage does notprovide assurance that it can revert to and operate properly in thecurrent limit mode that is necessary during the recovery periodfollowing a battery discharge event that the DC system is designedfor.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 an indication that the battery is partially discharged and itscapacity margins will be reduced.

The time to return the battery toits fully charged condition in this case is a function of the batterycharger capacity, the amount of loads on the associated DC system,the amount of the previous discharge, and the rechargecharacteristic of the battery.

The charge time can be extensive, andthere is not adequate assurance that it can be recharged within12 hours.Required Actions A.2 and E.2 require that the battery float current beverified less than or equal to 2 amps for the vital battery and lessthan or equal to 1 amp for the DG battery.

This indicates that, if thebattery had been discharged as the result of the inoperable batterycharger, it is now fully capable of supplying the maximum expectedload requirement.

The 2 amp value for the vital battery and theI amp value for the DG battery are based on returning the battery to98% charge and assume a 2% design margin for the battery.

If at theexpiration of the initial 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 notless than or equal to 2 amps for the vital battery or I amp for theDG battery, then this indicates there may be additional batteryproblems and the battery must be declared inoperable.

Required Actions A.3 and E.3 limit the restoration time for theinoperable battery charger 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 ifan alternate means of restoring battery terminal voltage to greaterthan or equal to the minimum established float voltage has beenused (e.g., balance of plant non-Class IE battery charger).

The72 hour Completion Time reflects a reasonable time to effectrestoration of the qualified battery charger to OPERABLE status.(continued)

(Gentikwed)

Watts Bar -Unit 2 B 3.8-56(developmental)

AH DC Sources -Operating B 3.8.4BASESACTIONS B.1 and F.1(continued)

Conditions B and F represent one channel (subsystem) with onebattery inoperable.

With one battery inoperable, the DC bus is beingsupplied by the OPERABLE battery charger.

Any event that resultsin a loss of the AC bus supporting the battery charger will alsoresult in loss of DC to that subsystem.

Recovery of the AC bus,especially if it is due to a loss of offsite power, will be hampered bythe fact that many of the components necessary for the recovery(e.g., diesel generator control and field flash circuits, AC load shedand diesel generator output circuit breakers, etc.) will likely relyupon the battery.

In addition, any DC load transients that arebeyond the capability of the battery charger and normally requirethe assistance of the battery will not be able to be brought online.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 aninoperable battery given that the majority of the conditions that leadto battery inoperability (e.g., loss of battery charger, battery cellvoltage less than 2.07 V, etc.) are identified in Specifications 3.8.4,3.8.5, and 3.8.6 together with additional specific Completion Times.C.1 and G.1Conditions C and G represent a loss of one DC electrical powersubsystem to completely respond to an event, and a potential lossof ability to remain energized during normal operation.

It is,therefore, imperative that the operator's attention focus onstabilizing the unit, minimizing the potential for complete loss of DCpower 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 withthe allowed time for an inoperable DC distribution subsystem.

(continued)

Watts Bar -Unit 2 B 3.8-57(developmental)

AH DC Sources -Operating B 3.8.4BASESACTIONS D.A and D.2(continued)

If one of the required DC electrical power subsystems is inoperable for reasons other than Conditions A or B for the vital batteries orConditions E or F for the DG DC electrical power subsystem, theremaining DC electrical power subsystem has the capacity tosupport a safe shutdown and to mitigate an accident condition.

Since a subsequent worst case single failure could, however, resultin the loss of the minimum necessary DC electrical subsystems tomitigate a worst case accident, continued power operation shouldnot exceed 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Completion Time is based onRegulatory Guide 1.93 (Ref. 8) and reflects a reasonable time toassess unit status as a function of the inoperable DC electrical power subsystem and, if the DC electrical power subsystem is notrestored to OPERABLE status, to prepare to effect an orderly andsafe unit shutdown.

If the inoperable Vital DC electrical powersubsystem cannot be restored to OPERABLE status within therequired Completion Time, the plant must be brought to a MODE inwhich the LCO does not apply. To achieve this status, the plantmust 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 5within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plantconditions from full power conditions in an orderly manner andwithout challenging plant systems.

The Completion Time to bringthe plant to MODE 5 is consistent with the time required inRegulatory Guide 1.93 (Ref.8).H.1If the DG DC electrical power subsystem cannot be restored toOPERABLE status in the associated Completion Time, theassociated DG may be incapable of performing its intended functionand must be immediately declared inoperable.

This declaration alsorequires entry into applicable Conditions and Required Actions foran inoperable DG, LCO 3.8.1, "AC Sources-Operating."

(continued)

(GGetiAed)

Watts Bar -Unit 2 B 3.8-58(developmental)

AH DC Sources -Operating B 3.8.4BASESSURVEILLANCE SR 3.8.4.1 and SR 3.8.4.2REQUIREMENTS Verifying battery terminal voltage while on float charge for the batteries helps to ensure the effectiveness of the battery chargers, whichsupport char9g4g

,ystem the ability of the batteries to perform theirintended function.

Float charge is the condition in which the charger issupplying the continuous charge required to overcome the internal lossesof a battery (or battery cell) and maintain the battery (or a battery cell) in afully charged state while supplying the continuous steady state loadsof the associated DC subsystem.

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

Thevoltage requirements are based on the nominal design voltage ofthe battery and are consistent with the minimum float voltageestablished by the battery manufacturer.

For example, the minimumnominal terminal voltage for the 5th Vital Battery is 136 V (62 cellstimes 2.20 Vpc); the minimum nominal terminal voltage for thevital batteries is 132 V (60 cells times 2.20 Vpc); and the minimumnominal terminal voltage for the DG batteries is 128 V (58 cells times2.20 Vpc). These voltage levels maintain the battery plates in acondition that supports maintaining the grid life.The voltage requirements listed above are based on the critical designvoltage of the battery and are consistent with the initial voltages assumedin the battery sizing calculations.

The 7 day Frequency is consistent withmanufacturer recommendations and IEEE-450 (Ref. 9).SURVEILL.\NCE SR 3.8.4.3(nti~ued)

Verifying that for the vital batteries that the alternate feeder breakers toeach required battery charger is open ensures that independence between the power trains is maintained.

The 7 day Frequency is basedon engineering

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

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

properly, with all required circuitbreakers closed and buses energized from normal power. The 7 dayFrequency takes into account the redundant DG capability and otherindications available in the control room that will alert the operator tosystem malfunctions.

(continued)

(G94Awed)

Watts Bar -Unit 2 B 3.8-59(developmental)

AH DC Sources -Operating B 3.8.4BASESS-R 3-8.4.5-and SR 3.8.".Visual inspection to detect corrosion of tho batter' coil6 and connoctions, Or m~asuromen9t of thoe resitncQ of oach inter cell, *nter rack, inter tfirand- terinlonection, provides an indication Of physical damage orabnormnal doterioration that could potontialy degrade bafttor,The- limits- es99tablisbh-d-forF thiS SR must be no more than 20% above therosistance as me~aur*ed duFrig installation, Or not above the coiling valueesF-t-ablishe-d by the manufacturwer.

The SurelaoFrequency for those inspections, Which can detectconditions th-at c-an cauepwer losses due to resistance heatini92 days. T-his Frequency is considered accoptable based- en oer)ating experience related to detecting corrosion tFreds.99-,444-7 Visual finspection of the b-ater,'

cells, cell plates, and batter,'

rackprovides an indication Of physical damage or abnormnal deterioration thatcould potentially degrade bailr, perfermanco.

The 12 month FrFequency for this SR is consistent with IEEE 450 (Ref. 9),which recomm~en~ds detailed visual inspection Of Gell condition and rackinRtegritY on a YearlY basis.(continued)

(GeRtined)

Watts Bar -Unit 2(developmental)

B 3.8-60AH DC Sources -Operating B 3.8.4BASESSU RVEILLANGE REQUIREMENTS SR 3.8.4.8.

SR 3.8.4.9 and SR 3.8.4.10Visual inspection and resistance mneaurements of inter c9ll, intor rack,inter tier, and- torminal connction provid-e nP ind-ication of physic~al damage Or abnOrMa!

deterioration that could indicate degraded batter;conditwion.

The anti corrosion mnaterial is used to help enSUre good-oloctrical cennoct-iens-and- to reduweq term~inal deterioIrato.

The visualinsooction for orrQoQio i; Anot inodo o ouiro rmova~l of Rnnrpection under each terminal connection...

The Fremo.Val Of Vi.ibcorrosior iS a pre.entiye mnaintenanc.

e SR. The presence o Of corrosion does not necessarily repFreset a failurwe of this SR provi'ded ViIGIEDu GurrF;u 9G wmvU Rng Poriom3nc a 01 9T bK 6.0 or I-OFpurposes Of trending, inter cell (vital and DG batteries) and inter tier (Vitaland DG batteries) connections are measured from batter; post to batter;post. Inter rack (Vital batteries),

inter tier (IDG Batteries),

and terminalconnections (Vital and DG batteries) are measured fromA teFrminal lug tobae~y post,The cnnec~tion resisrta~nce limits for SR 3.8.1.9 and SR 3.8.4.10 shalIl beno Moe% than 20%0 above the resistance as mneasured duringintlao, or not above the ceiling value established by the mnanufacturer-.

The Sur.'eillanco F-Fequencies of 12 moneths is consistent With IEEME 450(Ref. 9), which recommFends cell to cell and term~inal connection-resistance mneasurement on a yearly basis.SR 3.8.4.1This SR requires that each vital batter' charger be capable of Freharging its assocated batter' fromn a capacity Or serVice discharge test whilesupplying normnal leads, or alternatively, operating at cuwrrent limi*t forP Amnmmof 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> at a nominal 125 VDC. These requirements arebased on the design Gapasity of the chargers (Ref. 1) and theirperform~ance characteristic of current limfit operation for a substantial portion of the recharge period. Batter,'

charger output current is limited to110% to 125% onf the -200 amAp rated output. R9Gharging the batter,'

otesting forF a minimu;-m of 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is suffiient to verify, the output capabikity of the charger can be sustained, that current limit adjustments areproperly set and that PFotect'ye devices Will not inhibit porfGFrmanco atcurrent limfit settings.

According to Regulator; Guide 1.32 (Ref. 6), thebatter,'

charger supply is requirFed to be-: b--ased-on the !argest combineddemands of the various steady state leads and the Gharging capacity torestore the batter,'

fromn the design minimumF charge state to the fullycharged state, irrespective of the status of the plant during thos~e demandoccurrences.

Verifying the Gapability of the charger to operate insustained currFent limit cnionesrsthat these rqients, can besatisfied.

(continued)

Watts Bar -Unit 2(developmental)

B 3.8-61AH DC Sources -Operating B 3.8.4BASESSURVEII I t\r" SR 3.8.4.11 (continu-d)

REQU IREMENTSThe ~iir"niIhnrn l-rnntinn~v

~ ~ccontiblo olven mc olant conditions requir.ed to perform the test ;;Ad the other admini6.tative c ontr....

xistingto ensure adequate charger performnance during th96e 18 moneth interVals.

in addition, this Frequency is intended to be consistent with expected fue!Thisq SR is- modified by a Note. The reason forF the Note is that perfoFrming the Survoillanco mnay PeotUrb the electric al distribution system and-challenge safe systems.

his Sis AnogRally perFoed duringMODES 5 and 6 since it would require the DC e'ectriGca power subsytemto be inoperable durin~g performnance of the test. HoweVer, thisSurveillance mnay be performned in MOIDES 1, 2, 3, Or 4 provided the Vitallaý++a.X.

ig r,, ,ihr.+iti a,'Iq OR waa..ara ith I GOr tdata 1 -r'iraw+

mat, ha *tWJl 1 *fii ., i ta .. ,.tbanfar ian +d ak +nr attneta +i ft +1, ic, D r- vamlan -tnnnnr,evet6 may inGlude:;

ýIrw" M C3 MCI 0 0 .ncl=I1) UnexPected Gopeational events which causethe equi!pment peor Me dnc.-O ntctuon Bo th I aew'elrloman,-

, icr W,-ni badeeuat dcmntat;ionm Of thA required Derfqrmnance us aVAiWAble and...... .. ...... r --.I-, a:tin tht reuirs peforanceof his I* S..... JL... ~f!4 M, II ~ AM DI..... II ....provided the mainRtenanco was required, OF pBefFRmod i ojntowithmainenane rqurd to maintain OPERABILITY Or reliability.

(continued)

Watts Bar -Unit 2(developmental)

B 3.8-62SHI DC Sources -Operating B 3.8.4BASESS URPVEl1l IANICG-E SR -.8.44-2REQU......I.I...R-EME-N..iTS (GGoRiW~.e4

-t-HI6 am....................U..........................................to recharging its associated batter; fromn a capacity or sor.;icoe disccharge testwhile supplyin g normnal loads. T-his roquirmen9t is based on the designcapacity of the chargers (Ref. 13) and their perform~ance characteristic OfcurrenFA-t liMit oporation for a substantial portion Of the recharg PeRiOd.Batter; charger output curren-t is limited-to a maximum-of 140%9 of the20 amAp rated output. Recharging the batter; Verifies the output capability of the chargeFrcan be sustained, that current limit adjustmenRts rproperly ret and that proetec-tive devoices will not inhibit perfoFrmance atcurrent limnit sefttngs.

According to Regulator; Guide 1.32 (Ref. 6), thebailer,'

charger supply is required to be based on th lags combineddemnands of the vOariou,-s steady state Iead6 and the charging capacity torestore the batter' fromA the design miniMmum harge state to the ful~ycharged state, irrespeoct-Ve oaf the s-tatus, of the plant during these demnandoccurrences.

Verif,'ig the capability Of the charger to operate in a6setained cuwrre-nt limit conndmitin esrsthat these eqrmnts can beqsatisfied.

The Surveillance FrFequency is aGceptable, giVen the plant conditions required to perfoFrm the test and the eteramiisrtie otrols existingq to ensure adequate charger performnance during these 18 mon~th intervals.

In addition, this Frequencyi inen edt be consistent with expected fuelGeG&8 e8Rths-.PFo the DG DC eloctrica!

subsystem, this Survoillanco mnay be performned in MODES 1, 2, 3, Or 4 in conjunction With L-GCO .. .)ic the DG DCelectFical power subs6ystem Iuppl-o.lads only for the inoperable; dieselgenerator and would no9t otherxise challenge safet systems6 suppliedfromn vital electrical distribution systems.

A dditionally, credit mnay be takenfor unplanned events that satisf' this SR. Examples of unplanned eventsmay ARGiude*1 ) Unexpected operational eventS which cause the equipmnentt performA the funcionIG specified by this Survoillanco, for whichýadequate documentaitionof the required performnance Iavailable; aRd2-) PestA ncrrec-tive mnaintenance testing that requires perform~ance of-this Surveillance in order to restore the component toa O-PE-R-A.B-LF-,

provided the mnaintenanc

wsrqied, Or performed in conjunction Withmnaintenance required to mantIn OPRABILITY Or reliabwlity.

(continued)

Watts Bar -Unit 2(developmental)

B 3.8-63SHI DC Sources -Operating B 3.8.4BASESSURVEiLLANCE R-384.-3REQUIREMENTS4inue) A batter; ....i. e to.t, a .pe.ial Of batter,+

capability, as found, tosatisfy the deign r r ts (batte.,'

duty cYc!. ) of the PG electricalsysteM. T-hodc g Fate and test should toINorst cAs- design dut cc l.e requirements based on References 10The Surveillance FrFequoncy of 18 months is consistent with the-rec..Rmendations of RegulatFo' Guide 1.32 (Ref. 6) and Regulatorp Guide 1.1 29 (Ref. 11), which state that the ba#,e; seVice- test should beperformlced durFng refueling operatioRn orat outage,ith intervals betweeR tests, not to eXceed 18 mROnths.This S-R is- modified by b~s No-tesr.

Note 1 allows- the perfoq~ance of amodified performRance disc-harge test in lieu of a service test once per60 mnonths.

The moAd-ifi~ed perform~ance discharge test is a simulated dutycycle consisting Of just tWo rates: the o-ne minute rate published for thebatter' o the Iargest cu.. ent load Of the duty cycI fo-llowed by the testrate employed for the perform~ance test, both Of which envelope the dutycycl9eof the sepoir.'e test. Since the ampere hours remRoved by a rate-done mnutedischarge represents a very small peotien of the batter'capacity, the test rate can; be changed to that forF the perform~ance testwithout compromnising the result of the performnance discharge test. Thebatter; termin;al voltage for the moqdified perform~ance discharge testshou-ld remain above the minim.. batter' terminal voltage specified inthe batterF se-rvire fFr the dratien Rof time equal to that of the A modified d6hqetest is a test of the cat~ apacity aidits ability t,-, ro!fldi.,

uscharge batter;""

"*,h, and...; to.,

,provide a high rate, 6o94 duration lead (usually the highest rate of theduty GyGle.) This Will oft-e co'nfirmF the ba#tFy's ability to Meet the Fritialperiod of the load duty cycle, in addition to detefRm~inig its percontago ofrated capacity.

Initial conditions forF the moedified performnance discharge test should be these specified for a serv'ie test.The reason for Note 2 is that perfeFrming the Surveillance may peF4Urb the;Aital elecntric-al distr-ibution system and challenge safety systems.However, this SuPIeill~ancc may be perfermoed in MODES 1, 2, 3, or 4provided that Vital Battery V is substituted in accordance withLCO Note 1. For the DG DC e!ectrical subsystem, this suIlPlaSInce maybe perFormed in MODES 1 2, 3, ew i conjunction with 4 3.8 , .B Ysince the supplied loads are only forF the inaperable diesel generator and.would net ether~'ise challenge safety system leads which are supplied(continued)

Watts Bar -Unit 2(developmental)

B 3.8-64FHI DC Sources -Operating B 3.8.4BASESSURVEILLIA\N IGE SR 3.8.4.13 (contin~ued)

REQU IREMVENTS from~ vital electrical distribution systemAS.

Addi4tionally, croFdit mnay be takonfor unplanned eventS that satisfy this SR. Eixamplos of unplanned eyentsFey iRGId9&1 ) Unexpected oporatfional ovonts whic~h cause the equipment to-perfoFrm the, func-tion specified by thi6 SurVoilIaRG9, for Which-adequate documentation of the required performsance is available; and2) Post cor-rocntive m~aintn~anco te-sting that requires pcrf49rmanco Of thisSur.'oillanco in order to restore the comAponent to OPERABLE,-

provided the mnaintenance was required, or pe~rfor-med in conjuncGtion with mnaintenan~e required to maintain GPERDABILIT ojýr F liabi~ySR.-2.R4.14 Abatter; performnance discharge test is a test of constant curr~ent capasityof a batter,',

normnally done in the as found-cniin after having' boon in I%I.7 laccoptance test. Thno test is Rtenoea to aee81Frmie oereall battor;14 rraa A .,a A a + n Anl. -nw9rd a tyr-I taw 0 aga dri tood!3W.A batter' moedifiod performance disch~arge test is doscribod in the Basesfor SR 3.8.41.3 Either the batter; perform;anc discharge test Or themodified performance discharge test is acceptable for 6atisfyi~ng SR 3.8.4.14;

however, only the moedified perform~ance discharge test maybe used to satisfy~

SR 3.8.4.14 while 6atisf,'ing the requirementso SR 3.8.4.13 at the same time.The accepta~nce c~riteria for this Surweillance are consistent With IFEEE 50ID f aX aA 1MCAr ID fX r, c- Yk a.anc f.a .'4'n +ka+ +I-battr, be replaced if its capacity is below 80% of the msanufacturer rating. A capac~ity of 80% shows that the battory rate of deterioration isinc-mar.

inn a 4-n + +hm 0, a ranl +~nntt amttaInzr a,,rr~yvarl orw 5 a P w "apda V M%7 w "d rokati m Uri 5.(continued)

Watts Bar -Unit 2(developmental)

B 3.8-65FHI DC Sources -Operating B 3.8.4BASESSURVEILLANCE SR 3.8.4.14 (continued)

REQUIREMENTS The Su~ilneFrequencY forF this test is nrmFFally 60 mnonths.

if thebatter,'

shows degradation, or if the ba~qoy has, re~ached REM ofitexpoctod life and capacity is 4100% o-f the m~anu-facturerFs rating, theSurVeillance Frequency is reduced to 12 months. However, if the bafteryshoWs no degradation but has roachod 85%0 of its expected life, the8ur~oillance FrFequency is, only reduceAd-to :24 months, for baqtteries thatretain capacit"

ý100% Of the .manuRIfacAturer's rating. Degradationi
  • ndicated, accordinig to IEEE= 150 (Ref. 0), When the batter! capacitydrops by moreA than I10% relative to itGapacity OR theB preViouspe~feFmaF;Ge tes6t Or When it is ->10% below-4.

thte manu1facturer rating.These Frequece arecnsistent with the recomernedations in IEEE 450(Ref. )This SR is modified by aR Note. The r-eason for the Note is that pe~fGFming the Surveillanae mnay pe~turb the vital electWArica distribution system andchallenge safety systems.

However, this Suryoillanco may be pe~feFmod in MOIDES I, 2, 3, Or 4 provided that Vital Batteny V is- isubshtit-uted inaccordance with. the- LCO Note. For the- -Q DG- D electrical subsystem, thissur~veillance mnay be pe~fGFmed in MODES I, 2, 3, or 4 in conjunction WithLCOG 3.8.4 .B since the supplied leads are only for the inoperable dioesegenerator and would not etheorwise c~hallen~ge safety system lea;ds whichare supplied fro~m v.it-al electrica!

distribution systems.

Additionally, creditmnay be taken for unplanned events that satisfy' this SR. IExamples ofunplanned 6evets m~ay includ e:1) Un~eXpected operational evoenRts

%which cause the equipment to9-uuIQFui=+H LrnJ+!- ui.url MuGiu4i:3 HU tIiii 01.J.1ý--

..b... W'.........I ...adequate documen9t-at-ion of the required ponertomancoe is- available; and2) Post corrective msaintenance testinqI that requires qo40frmaRce of thisII Iprovided the maintenance equired, Or poV in, coFnjuntion wit;hm~aintenance required to maintain OPER.AB-ILITY or reliability.

(continued)

Watts Bar -Unit 2(developmental)

B 3.8-66BH DC Sources -Operating B 3.8.4BASES (continued)

SURVEILLANCE REQUIREMENTS (continued)

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

According to Regulatory Guide 1.32 (Ref. 6), the batterycharger supply is recommended to be based on the largestcombined demands of the various steady state loads and thecharging capacity to restore the battery from the design minimumcharge state to the recharged state, irrespective of the status of theunit during these demand occurrences.

Verifying the capability ofthe charger to operate in a sustained current limit condition ensuresthat these requirements can be satisfied.

The SRs provide two options.

One option requires that eachvital battery charger be capable of supplying 200 amps (20 amps forthe DG battery charger) at the minimum established float voltage for4 hours. Recharging the battery or testing for a minimum of 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />sis sufficient to verify the output capability of the charger can besustained, that current limit adjustments are properly set and thatprotective devices will not inhibit performance at current limitsettings.

The other option requires that each battery charger be capable ofrecharging the battery after a service test coincident with supplying the largest coincident demands of the various continuous steadystate loads (irrespective of the status of the plant during whichthese demands occur). This level of loading may not normally beavailable following the battery service test and will need to besupplemented with additional loads. The duration for this test maybe longer than the charger sizing criteria since the battery rechargeis affected by float voltage, temperature, and the exponential decayin charging current.

The battery is recharged when the measuredcharging current is < 2 amps for the vital batteries and < I amp forthe DG batteries.

The Surveillance Frequency is acceptable, given the plantconditions required to perform the test and the other administrative controls existing to ensure adequate charger performance duringthese 18 month intervals.

In addition, this Frequency is intended tobe consistent with expected fuel cycle lengths.(continued)

Watts Bar -Unit 2(developmental)

B 3.8-67SH DC Sources -Operating B 3.8.4BASES (continued)

SURVEILLANCE SR 3.8.4.7REQUIREMENTS A battery service test is a special test of battery capability, as(continued) found, to satisfy the design requirements (battery duty cycle) ofthe DC electrical power system. The discharge rate and testlength should correspond to worst case design duty cyclerequirements based on References 10 and 12.The Surveillance Frequency of 18 months is consistent with therecommendations of Regulatory Guide 1.32 (Ref.6) andRegulatory Guide 1.129 (Ref.11),

which state that the batteryservice test should be performed during refueling operations or atsome other outage, with intervals between tests, not to exceed18 months.This SR is modified by two Notes. Note I allows the performance of a modified performance discharge test in lieu of a service test.The modified performance discharge test is a simulated dutycycle consisting of just two rates; the one minute rate published for the battery or the largest current load of the duty cycle,followed by the test rate employed for the performance test, bothof which envelope the duty cycle of the service test. Since theampere-hours removed by a rated one minute discharge represents a very small portion of the battery capacity, the testrate can be changed to that for the performance test withoutcompromising the results of the performance discharge test. Thebattery terminal voltage for the modified performance discharge test should remain above the minimum battery terminal voltagespecified in the battery service test for the duration of time equalto that of the service test.Note 2 allow the plant to take credit for unplanned events thatsatisfy this SR. Examples of unplanned events may include:1) Unexpected operational events which cause the equipment toperform the function specified by this Surveillance, for whichadequate documentation of the required performance isavailable; and2) Post corrective maintenance testing that requires performance of this Surveillance in order to restore the component toOPERABLE, provided the maintenance was required, orperformed in conjunction with maintenance required tomaintain OPERABILITY or reliability.

(continued)

Watts Bar -Unit 2 B 3.8-68(developmental)

BH DC Sources -Operating B 3.8.4BASES (continued)

REFERENCES

1. Title 10, Code of Federal Regulations, Part 50, Appendix A,General Design Criterion 17, "Electric Power System."2. Regulatory Guide 1.6, "Independence Between Redundant Standby(Onsite)

Power Sources and Between Their Distribution Systems,"

U.S. Nuclear Regulatory Commission, March 10, 1971.3. IEEE-308-1971, "IEEE Standard Criteria for Class IE PowerSystems for Nuclear Power Generating Stations,"

Institute ofElectrical 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 of Electrical 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 41980i!199, "IEEE RecomFendod Practice forMaintenance Testing and Roplacomont of Large Load Storage-BatteFrie for Generating Stations and Subsystemrs,"

Institute ofElectricnal

,and E!ectronic Engineers.IEEE-450-2002, "IEEERecommended Practice for Maintenance, Testing andReplacement of Vented Lead -Acid Batteries for Stationary Applications,"

Institute of Electrical and Electronics Engineers, Inc.10. :WA Calc'u-ltihn WB.N EEB MS T-1 ! 0003, "125 VDC Vital Batter'and Evaluatien."TVA Calculation EDQ00023620070003, "125V DC Vital Battery System Analysis"

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

U.S. Nuclear Regulatory Commission, February1978.12. TVA Calculation WBN EEB-EDQ00023620070003, "125V DC VitalBattery System Analysis."

13. Watts Bar FSAR, Section 8.3.1, "AC Power System."Watts Bar -Unit 2 B 3.8-69(developmental)

SH DC Sources -ShutdownB 3.8.5BASES (continued)

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

cabling, are required to be OPERABLE to supportrequired trains of the distribution systems required OPERABLE byLCO 3.8.10, "Distribution Systems -Shutdown" and the required DGsrequired OPERABLE by LCO 3.8.2, "AC Sources -Shutdown."

As aminimum, one vital DC electrical power train (i.e., Channels I and Ill, orII and IV) and two DG DC electrical power subsystems (i.e., 1A-A and2A-A or 1 B-B and 2B-B) shall be OPERABLE.

This ensures theavailability of sufficient DC electrical power sources to operate the plant ina safe manner and to mitigate the consequences of postulated eventsduring shutdown (e.g., fuel handling accidents).

The LCO is modified by athree Notes. The-Note I indicates that VitalBattery V may be substituted for any of the required vital batteries.

However, the fifth battery cannot be declared OPERABLE until it isconnected electrically in place of another battery and it has satisfied applicable Surveillance Requirements.

Note 2 indicates that spare vitalchargers 6-S, 7-S, 8-S, or 9-S may be substituted for required vitalchargers.

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

However, thespare charger(s) cannot be declared OPERABLE until it is(are)connected electrically in place of another charger, and it hassatisfied applicable Surveillance Requirements.

APPLICABILITY The DC electrical power sources required to be OPERABLE in MODES 5and 6, and during movement of irradiated fuel assemblies, provideassurance 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 arecovered in LCO 3.8.4.(continued)

Watts Bar -Unit 2 B 3.8-63(developmental)

AH DC Sources -ShutdownB 3.8.5BASES (continued)

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 withDC power available may be capable of supporting sufficient systems toallow continuation of CORE ALTERATIONS and fuel movement.

Byallowing the option to declare required features inoperable with theassociated vital DC power source(s) inoperable, appropriate restrictions will be implemented in accordance with the affected required featuresLCO ACTIONS.

In many instances, this option may involve undesired administrative efforts.

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

The Required Action to suspend positive reactivity additions does not preclude actions to maintain or increase reactor vesselinventory, provided the required SDM is maintained.

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

These actions minimizeprobability of the occurrence of postulated events. It is further required toimmediately initiate action to restore the required vital DC electrical powersubsystems and to continue this action until restoration is accomplished in order to provide the necessary DC electrical power to the plant safetysystems.The Completion Time of immediately is consistent with the required timesfor actions requiring prompt attention.

The restoration of the requiredvital DC electrical power subsystems should be completed as quickly aspossible in order to minimize the time during which the plant safetysystems may be without sufficient power.B.1If the-one or more DG DC electrical power subsystem cannot be restoredto OPERABLE status in the associated Completion Time, the associated DG may be incapable of performing its intended function and must beimmediately declared inoperable.

This declaration also requires entry intoapplicable Conditions and Required Actions for an inoperable DG, LCO3.8.2, "AC Sources -Shutdown."

(continued)

Watts Bar -Unit 2 B 3.8-64(developmental)

AH DC Sources -ShutdownB 3.8.5BASES (continued)

SURVEILLANCE REQUIREMENTS SR 3.8.5.1SR 3.8.5.1 requires performance of all Surveillances required bySR 3.8.4.1 through SR 3.8.4.4-47.

Therefore, see the corresponding Bases for LCO 3.8.4 for a discussion of each SR.This SR is modified by a Note. The reason for the Note is to precluderequiring the OPERABLE DC sources from being discharged below theircapability to provide the required power supply or otherwise renderedinoperable during the performance of SRs. It is the intent that these SRsmust still be capable of being met, but actual performance is not required.

REFERENCES

1. Watts Bar FSAR, Section 15, "Accident Analysis" and Section 6,"Engineered Safety Features."
2. Watts Bar FSAR, Section 8.0, "Electric Power."Watts Bar -Unit 2(developmental)

B 3.8-65AH Battery GeU-Parameters B 3.8.6B 3.8 ELECTRICAL POWER SYSTEMSB 3.8.6 Battery Ge94-Parameters BASESBACKGROUND This LCO delineates the limits on battery float current, electrolyte temperature, electrolyte level, and cell float voltage, and spocific for the 125V vital DC electrical power subsystem and the diesel generator (DG) batteries.

A discussion of these batteries and their OPERABILITY requirements is provided in the Bases for LCO 3.8.4, "DC Sources -Operating,"

and LCO 3.8.5, "DC Sources -Shutdown."

Additional controls for various battery parameters are also provided inSpecification 5.7.2.21, "Battery Monitoring and Maintenance Program."

The battery cells are of flooded lead acid construction with a nominalspecific gravity of 1.215. This specific gravity corresponds to an open cellvoltage of 2.07 Volts per cell (Vpc). For a 58 cell battery (DG battery),

thetotal minimum output voltage is 120 V; for a 60 cell battery (vital battery),

the total minimum output voltage is 124 V; and for a 62 cell battery,(51h vital battery),

the total minimum output voltage is 128 V. The opencircuit voltage is the voltage maintained when there is no charging ordischarging.

Once fully charged, the battery cell will maintainapproximately 97% of its capacity for 30 days without further charging permanufacturer's instructions.

Optimal long term performance,

however, isobtained by maintaining a float voltage from 2.20 to 2.25 Vpc. Thisprovides adequate over-potential, which limits the formation of lead sulfateand self discharge as discussed in FSAR, Chapter 8 (Ref. 4).(continued)

Watts Bar -Unit 2(developmental)

B 3.8-66AH Battery GeU-Parameters B 3.8.6BASES (continued)

APPLICABLE SAFETYANALYSESThe initial conditions of Design Basis Accident (DBA) and transient analyses in the FSAR, Section 6 (Ref. 1) and Section 15 (Ref. 1), assumeEngineered Safety Feature systems are OPERABLE.

The vital DCelectrical power system provides normal and emergency DC electrical power for the emergency auxiliaries, and control and switching during allMODES of operation.

The DG battery systems provide DC power forthe DGs.The OPERABILITY of the DC subsystems is consistent with the initialassumptions of the accident analyses and is based upon meeting thedesign basis of the plant. This includes maintaining at least one train ofDC sources OPERABLE 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 aee-parameters satisfy the Criterion 3 of the NRC PolicyStatement.

LCOBattery aee-parameters must remain within acceptable limits to ensureavailability of the required DC power to shut down the reactor andmaintain it in a safe condition after an anticipated operational occurrence or a postulated DBA. Ele-GtelýteBattery parameter limits areconservatively established, allowing continued DC electrical systemfunction even with Category A and- B limits not met. Additional controls for various battery parameters are also provided inSpecification 5.7.2.21, "Battery Monitoring and Maintenance Program."

APPLICABILITY The battery aG9-parameters are required solely for the support of theassociated vital DC and DG DC electrical power subsystems.

Therefore, battery eleGtre9hy4e

-sparameter limits are only required when the DCpower source is required to be OPERABLE.

Refer to the Applicability discussion in Bases for LCO 3.8.4 and LCO 3.8.5.(continued)

Watts Bar -Unit 2(developmental)

B 3.8-67AH Battery B 3.8.6BASES (continued)

AGTIQNlt A ..........

.. II_ .... ....... L=! .... L ___'_LL_'=

i! --MvTtn oneRA or1 more c I As in 9 on F or oe oRaIIoRies not1 w RItni imiRS k" -,Category A limits not mnet, Category B limits; not met, or Category A and BliMit6 not mnet) but within the Category C limfitG Gpocified in Table 3.8.6 1... .-..... ......,, ,. .m r O.. no.J............-.

.J --....-~.. ... ...,v .........

in thA nnnA gaF;%1*Ag LGQ the ba#ecu *r, d9CIFaded but theFe 4r* 6tilla4ffected WAtt, sntrqie ob osdrdioeal sol1ely as aresult of Category A or B limi~t6 not mnet, and operation

-6 permnited for aliiedfpe~iGEI The pilot Goelectrolyt4e leyel and float Yoltage are required to be verifiedto mooet the Category C limit Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> (Required Action A.1). T-hischeck Will proVide a quick iniainof the status rcf the remainder Of thebatter' cells. One hour providesA tilme to inspect the electrolyte level andto confiFrm the float voltage of the pilot c8lls. Onie hour is considered areaRsonabl e amonunt of timne to ee-drfom.

the renquired-v~eqrfic~ationF.

% / ;.r. +; +k + +11 t- + f, 1; ;+ + 0 ; A A +;provides assurance that during the time needed to restore the parame~ters to the Categor,'

A and B limits, the battery is, still capable of pe~f9Fming Itsintended fUR4tio.

A period- of 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is F;allowed to comnplete the 9 taverification because specifi gravity mneasurements must be obtained foreach cOnn~ected cell. Takin~g *into consideration both the time required top9efGrm the Fequired Verification and the assurance that the batter' Gel!parameters agre not rseverelY

degraded, this tim~e is, coAnsid~ereAd_

re.;r9asonabl.

The verfication is repeated at 7 day intorvals until theparameters are restored to Category

,A ,and B limits. This periodiverificOationA is consistent

.wfith the noArmFal FrequencGy Of pilot cell-Continued oporation is only permitted for 31 days be fore battery ~ellparame~ters mus1t be4 res6toreAd to_ within Category A. and B limnits.

With theconsi6deration that, while battery capact isdgrdd, sufficient capacityeXists tOp normF~ the intended function ndto lo time to fuly restorethe batter' cell parameters, to normnal limits,1 thiS time is acceptable prier todocAinkun the b~atter iRnonrabhLo.

j. ... -(continued)

Watts Bar- Unit 2(developmental)

B 3.8-68AH Battery Gell-Parameters B 3.8.6BASES,ACTIONS 84(GORtiRued)

With one or more8 batteries With 9Re Or MoA-re- bhaA#er,'

Goil parame;ter outside the Catgor, C Imi,,ts for any

ci11, capacity tosupply thoeaiu 1erpoctd load Fegu*roment 0s not assurod and thecorrespondin
ia Co DG DG e!octrical poWor subsystemn must bedoclaroed inoeporable.

Additionally, othor potontially oXreFme conditions, SUch as not Gom.pleting the Re.uirod Act8QiRn of Condition A within thoreguirod Completion Timo oravrae&8etrl1o4 teMprature ofreprGesetative co1ls falling below 602F for the vital batt1eries or 500F forDGbateieare als1asefrimeitl declaFrin the associlated vital DG Or DG DG oloctrical power subsystem inoperable.

ACTIONS A.I. A.2. CA,. C.2, and C.3If one required vital battery or one required DG battery has one ormore cell voltage < 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 chargerOPERABILITY is made by monitoring the battery terminal voltage(SR 3.8.4.1 or SR 3.8.4.2) and of the overall battery state of charge bymonitoring 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 performthe intended function.

Therefore, the affected battery is not requiredto be considered inoperable solely as a result of one or more cells inone battery < 2.07 V and continued operation is permitted for alimited 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 SR3.8.4.1, SR 3.8.6.1, SR 3.8.4.2, or SR 3.8.6.2 acceptance criteria doesnot result in this Required Action not met. However, if one of theSRs is failed, the appropriate Condition(s),

depending on the causeof the failures, is entered.

If SR 3.8.6.1 or SR 3.8.6.2 is failed, thenthere is not assurance that there is still sufficient battery capacity toperform 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 requiredDG battery with float current > 1 amp indicates that a partialdischarge of the battery capacity has occurred.

This may be due toa temporary loss of a battery charger or possibly due to one or morebattery cells in a low voltage condition reflecting some loss ofcapacity.

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 2 B 3.8-69(developmental)

AH Battery GeU-Parameters B 3.8.6BASESACTIONS B.1. B.2, D.1. and D.2 (continued)

If the terminal voltage is found to be less than the minimumestablished float voltage, there are two possibilities, the batterycharger is inoperable or is operating in the current limit mode.Conditions A and C address charger inoperability.

If the charger isoperating 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 has been substantially discharged andlikely cannot perform its required design functions.

The time toreturn the battery to its fully charged condition in this case is afunction of the battery charger capacity, the amount of loads on theassociated DC system, the amount of the previous discharge, andthe recharge characteristic of the battery.

The charge time can beextensive, and there is not adequate assurance that it can berecharged 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). Thebattery must therefore be declared inoperable.

If the float voltage is found to be satisfactory, but there are one ormore battery cells with float voltage less than 2.07 V, the associated "OR" statement in Condition H is applicable and the battery must bedeclared inoperable immediately.

If float voltage is satisfactory andthere are no cells less than 2.07 V, 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 its recharged 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) acrossits terminals indicates that the battery is on the exponential charging current portion (the second part) of its recharge cycle. Thetime to return a battery to its recharged state under this condition issimply a function of the amount of the previous discharge and therecharge 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 apremature shutdown with its own attendant risk.If the condition is due to one or more cells in a low voltage condition but still greater than 2.07 V and float voltage is found to besatisfactory, this is not indication 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 time prior to declaring thebattery inoperable.

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

a failureof SR 3.8.4.1 or SR 3.8.4.2 acceptance criteria does not result in theRequired Action not met.However, if SR 3.8.4.1 or SR 3.8.4.2 is failed, the appropriate Condition(s),

depending on the cause of the failure, is entered.(continued)

Watts Bar -Unit 2 B 3.8-70(developmental)

AH Battery ,eII-Parameters B 3.8.6BASESACTIONS(continued)

E.1. E.2. and E.3With one required vital or DG battery with one or more cellselectrolyte level above the top of the plates, but below the minimumestablished design limits, the battery still retains sufficient capacityto perform the intended function.

Therefore, the affected battery isnot required to be considered inoperable solely as a result ofelectrolyte level not met. Within 31 days, the minimum established design limits for electrolyte level must be re-established.

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

Required Actions E.1 and E.2address this potential as well as provisions in Specification 5.7.2.21.b, "Battery Monitoring and Maintenance Program."

They aremodified by a Note that indicates they are only applicable ifelectrolyte 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 />, levelis required to be restored to above the top of the plates. TheRequired Action E.2 requirement to verify that there is no leakage byvisual inspection and the Specification 5.7.2.21.b item to initiateaction to equalize and test in accordance with manufacturer's recommendation are taken from IEEE Standard 450. They areperformed following the restoration of the electrolyte level to abovethe top of the plates. Based on the results of the manufacturer's recommended testing the battery may have to be declaredinoperable and the affected cell(s) replaced.

F.1With one required vital or DG battery with pilot cell temperature lessthan the minimum 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 torestore the temperature to within limits. A low electrolyte temperature limits the current and power available.

Since thebattery is sized with margin, while battery capacity is degraded, sufficient capacity exists to perform the intended function and theaffected battery is not required to be considered inoperable solelyas a result of the pilot cell temperature not met.(continued)

Watts Bar -Unit 2(developmental)

B 3.8-71AH Battery Gel4-Parameters B 3.8.6BASESACTIONS(continued)

G.1With more than one required vital or more than one required DGbatteries with battery parameters not within limits as specified inConditions A through F there is not sufficient assurance that batterycapacity has not been affected to the degree that the batteries canstill 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 uponthe batteries.

The longer Completion Times specified for batteryparameters on non-redundant batteries not within limits aretherefore not appropriate, and the parameters must be restored towithin 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 theallowances of the Required Actions for Condition A, B, C, D, E,F or G, sufficient capacity to supply the maximum expected loadrequirement is not assured and the corresponding battery must bedeclared inoperable.

Additionally, discovering one or more batteries with one or more battery cells float voltage less than 2.07 V and floatcurrent greater than 2 amps for the vital batteries or 1 amp for theDG batteries indicates that the battery capacity may not be sufficient to perform the intended functions.

Under these conditions, thebattery must be declared inoperable immediately.

(continued)

Watts Bar -Unit 2(developmental)

B 3.8-72AH Battery ,eU-Parameters B 3.8.6BASESSURVEOLLA.NGE SR 3.8.64REQUIREMENTS This 2SR verifirs that Catogo- ; A batt'o Gel' .a..tr ..o cosstnwith IEEE1450 (Rof. 2), Whi:h rocommondS ba#e,'. inspetrions (at least ono per moenth) including

voltage, 6pecific
grayity, and 8'ectrolyte temporature Of pilot cells.SR Tho 'uarterly inSPectio n9f specific gravity and voltage s cofnsistont withIEEE 450 (Ref. 2). In addition, within 21 hour2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br />" of a batter,'

dischaFrg

-c110 V (1 13.5-V for Vital Batter; V or 106.5 V for DG battories) or abatter,'

overcharge

>- 150 V. (1 55 V for Vital Battor,'

V or 1145 V. forDG batteries),

the batter; must be de-monstr-ated-to Meet Category B9li.mi*ts.

Tran;;sientS, such as mo~tor starting transients, which m:ayLmomenGtarily cause batter,'voltage to drop to 110V (113.5 Vfor VitalBatter; V or 1068.5 V for DG battorios),

do not constitute a batter;-discharge provided the batter' term~inal voltage and float current retuIrn topro transient values. This inspection isa!so consistent with .1EEE 450(Ref. 2), which recoAGm.men8ds special inspections following a seVeredischarge Or overcharge, to ensurwe that no significant degradation of thebatter; occurs as a consequence Of SUch discharge Or overcharge.

This Survoillance verificationA that the average temperature ofrapresentatiVo cells is ! 600F for the vital batteries, and ! 50"F for theDG batteries, 06 consistent with a recommFendation of IEEE=F 450 (Ref. 2),that s-taRtesR that the temnperatureF of electrolytes in representative cellsshould be deteFrmined on a quarterly basis.(continued)

Watts Bar -Unit 2(developmental)

B 3.8-73AH Battery ,e4-Parameters B 3.8.6BASESRI IRIEII I AIICE SR 3.8.6 (GOntnuord)

REQUIREME.NTS Lowor .....thAn nrMa tem.peratures act to ihibit orh ro.duco ' capacity.

T-his SR ensureAs-that tho operating tomApGratures romain within anaccoptablo operating range. This limnit is based an mnanUfacturor roconMMenAdations.

Table 3.8.6 IThis table dolinoatos the limits on oloctrolyte level, float voltage,-anid Tpecific graVity f or thret drifferent tego'ri ... The of accateger,'

is discussed belowA.gCateogeo' A delfinReF thoe OIal limit for each desigrated coA-l in oacRAh batter,.

The cells seloctod as pilot Goils -Are thoseA whoco6tomnPoratUro,

voltage, and electrolye spccific gravity approxim~ate theState Of charge of the entire batter,'.

The Categor,'

A limits specified for oloctro','t level are based enmsanufactrer recommF:enda;-tions[

and- are con~sistent with the guidance iIEEE 450 (Ref. 2), with the extra .1nc,4 lwac above the high waterlevel iRndiation for operatiq ng argin to accoun--t for temperatures andcharge effects.

In -aCdditionR to this. allowanco, footnote (a) to Table 3.8.6 1perm~its the electrolyte level to- be- -above the specified maximum levelIduring equal'iig charge, provided it is not OvoF:oW*Rg.

Those limitsenAsure that the plates suffer no physical damage, and that adequateelectFro transfercapabilipF ir, maintained in the event Of transient-conditions.

IEEFE 450 (Ref. 2) recommends that electrolye level readingsshudbe mnade only after the bhatter, has boon at float charge for at leastT7 he togd2Th Gat1e. .. .. .limi Lp~ fe JG 90a ........

2.1 V: .... eell r_{ 16iu 0;Rsf- paOR IRA M rocmmnouGnS OT Intm 'iow kr. d), WRucRiStates that prolonged operation of cells 4 2.13 V can reduce the lifeexpectancy of colls.The Categer,'

A limit specified for specific gravity for each pilot cell is> 1.200 (0.015 below the manufacturer fully charged nominal specificqraVity or a batter,'

charging current that had- Stabilized at a low value).This value is characteristic ofta charge-d cell1 with adequate capacity.

ArrGdinFg to IEEE 450 (Ref. 2), the specific gravity readings are basedon a tem-eratur' of 77°F (250C).V-._ _ \__ w j_(continued)

Watts Bar -Unit 2(developmental)

B 3.8-74AH Battery ,eU-Parameters B 3.8.6BASESSURVEILL'ANCE SR 3.9.@.3 (con~tin~ud)

REQUIREMENTS; Tk^ P^t* cýn~~ nrr. ^^ n~ ,npr rrnntnM far gnt #a -I nrn.Ai c t, "20C 4 a'70t- k "770C '3r.Ofl I +(0.001) is added to the reading; 1 point iS f.r each ,oF be.ow770P. The specific gIr ai of IItho oetýrolyte in a cell increasos with a lossof water due to or e-aporation.

Category B defines the normaI ParFameteFr limlit fr9 each connected Geil.The term, "connoc3ted cel!" excludes any batte, il that may bejumApred Out.The Category B3 limits specified for electrolyt!ee lo and float Yeltage arethe same as those specified for Categor~'

A and have boon discusse13d above. The Category B3 limit specified for specific gravity for each4connected

%1il is ! 1. 195 (0.020 below the man;ufacturer fuly charged,nem~inal specific gravity)

With the aYeragc of all connected calls >1.205(0.010 below the mqanufacturer fuly charged, Gnoinal 6pecific gravity).

These values AreA ba6Red on manufac~t~urer's recommendations.

Theminmu speific gravity value required for each cell1 ensures that theeffectIs

-of a;; highly charged or neWly inIstaled coil wilIIIl not Mask overalldegradation of the batery.ýCategory C defines the limits for each cell. These values,although

reduced, provide assurance that sufficent capacity exists toperformA the intended function and mnaintain a mnargin of safet. When anybattery parameter is outside the Category C limits, the assurance ofsufficient capacity described above no lon~ger exists, and the battery mnustbe declared inoperable.

The Gateaor; C limits specified for eloctrol~e leyel (above the top of theLL =l IL = -I--i= -- + ....Iplates ana not OVO......g.

ensure Mal !Re plafs 6U-,F or no pRysicaldamage and mnaintain adequate electFro transfer capability.Th Category C li.mits fo-r float# voltage is ba~se~d onA IEEE 450 (Ref. 2), whichstates that a cell voltage of 2.07 V or below, under float conditions andnot caused by elevated temperatue of the Gl', irdicates internal cellproblems and May roquire cell replacemnent.

The Cwategory C limFits of average specific gravity 115ibaeonR manufacturer recommendations (0.020 below the manufactJurerF recommended fully ch~arged, nominal specific gravity).

In addition to thatlimnit, it is required that the specific gravity forF each cnen~ecnted-cell mu st beno) less than 0.020 below the average of all connected cells. This limitens'-res that the effect of a highly charged or neW cell does not maskoveaell 4dAradatior of the ............

.1"(continued)

Watts Bar -Unit 2(developmental)

B 3.8-75AH Battery Ge4-Parameters B 3.8.6BASESS1UIRVED\I I AlQ l F-REQUIREMENTS SR 3.80.6.3 (continUod)

X Ino MAeotnote to- 4i polo ui-A1 are aoeiicaoio To 6a19ooorv A .1na uRR..... ...... FE ..........

... -j --7 -spociti gravity.

ootnote (b) to Tal 30 .9.6 1 requi'r4Rs-the ahQovementioned corection for olocrolyto9 level and temperature, withthexception that !eyel correc-tionA i6 not required when batter; charginig cu-'rArnt is; 2 amps OR float charge for vital b~attrioc and -1.0 amps forDG batteies.

This currenFtA

provides, in general.

an indication of oereallBersause of specifics gravity gradients that are produced during threcharging

process, delays Of several days May occur While waitfing forthe specific gravity to stabilize.

A stabilized charger current is aacceptable alternative to specific graVity mneasuremen~t for doteFRmining thesta-te Of charge. This phenomenon is discusse i~n IEEEF 450(Rf2)Cnnnnf I n^ T-,hi- '1 9 fi I ,Ipp.th^

finp* ^1,r tq g-rrnt t g) , ea 'can alte"rate to SpeiAfGc f-r Up to 31 days followinr a ba'te,',recharge.

Within 31 days, each connected cell's specific gravity mAust beme-ý;-asurd-to- cn-firmn the sotate of chage. Following a minorG batter;recharge (such as equalizing charge that does not fellw a deep-discharge),

specific graVity gradients are no~t Significant, and conf4Frming me~asuremen8ts May be8 made in less than 31 days.-SURVEILLANCE REQUIREMENTS SR 3.8.6.1 and SR 3.8.6.2Verifying battery float current while on float charge is used todetermine the state of charge of the battery.

Float charge is thecondition in which the charger is supplying the continuous chargerequired to overcome the internal losses of a battery and maintainthe battery in a charged state. The equipment used to monitor floatcurrent must have the necessary accuracy and resolution tomeasure electrical currents in the expected range. The float currentrequirements are based on the float current indicative of a chargedbattery.

The 7 day Frequency is consistent with IEEE-450 (Ref. 2).This SR is modified by a Note that states the float currentrequirement is not required to be met when battery terminal voltageis less than the minimum established float voltage of SR 3.8.4.1 orSR 3.8.4.2.

When this float voltage is not maintained, the RequiredActions of LCO 3.8.4 ACTION A or E are being taken, which providethe necessary and appropriate verifications of the battery condition.

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

Watts Bar -Unit 2(developmental)

B 3.8-76AH Battery Ge1-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS (continued)

SR 3.8.6.3 and SR 3.8.6.6Optimal long term battery performance is obtained by maintaining float voltage greater than or equal to the minimum established design limits provided by the battery manufacturer which is2.20 Vpc. This corresponds to a terminal voltage of 128 V for theDG batteries, 132 V for vital batteries I through IV and 136 V forvital battery V. The specified float voltage provides adequateover-potential, which limits the formation of lead sulfate andself discharge, which could eventually render the battery inoperable.

Float voltages in this range or less, but greater than 2.07 Vpc, areaddressed in Specification 5.7.2.21.

SRs 3.8.6.3 and 3.8.6.6 requireverification that the cell float voltages are equal to or greater thanthe short term absolute minimum voltage of 2.07 V.The Frequency for cell voltage verification every 31 days for pilotcell and 92 days 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 sufferno physical damage and maintain adequate electron transfercapability.

The minimum design electrolyte level is the minimumlevel indication mark on the battery cell jar. The Frequency isconsistent with IEEE-450 (Ref. 2).SR 3.8.6.5This Surveillance verifies that the pilot cell temperature is greaterthan or equal to the minimum established design limit (i.e., 60 *F forvital batteries and 50 °F for DG batteries).

Pilot cell electrolyte temperature is maintained above this temperature to assure thebattery can provide the required current and voltage to meet thedesign requirements.

Temperature lower than assumed in batterysizing calculations will not ensure battery capacity is sufficient toperform its design function.

The Frequency is consistent withIEEE-450 (Ref. 2).design requirements.

Watts Bar -Unit 2(developmental)

B 3.8-77AH Battery eI4-Parameters B 3.8.6BASESSURVEILLANCE SR 3.8.6.7REQUIREMENTS A battery performance discharge test is a test of battery capacity(continued) using constant current.

The test is intended to determine overallbattery degradation due to age and usage.Either the battery performance discharge test or the modifiedperformance discharge test is acceptable for satisfying SR 3.8.6.7;however, only the modified performance discharge test may be usedto satisfy the battery service test requirements of SR 3.8.4.7.A modified performance test is a test of the battery capacity and itsability to provide a high rate, short duration load (usually the highestrate of the duty cycle). This will often confirm the battery's ability tomeet the load duty cycle, in addition to determining its percentage ofrated capacity.

Initial conditions for the modified performance discharge test should be identical to those specified for a servicetest.It may consist of just two rates; for instance the one minute rate forthe battery or the largest current load of the duty cycle, followed bythe test rate employed for the performance test, both of whichenvelope the duty cycle of the service test. Since the ampere-hours removed by a one minute discharge represents a very small portionof the battery capacity, the test rate can be changed to that for theperformance test without compromising the results of theperformance discharge test. The battery terminal voltage for themodified performance discharge test must remain above theminimum battery terminal voltage specified in the battery servicetest for the duration of time equal to that of the service test.The acceptance criteria for this Surveillance are consistent withIEEE-450 (Ref. 2) and IEEE-485 (Ref. 3). These references recommend that the battery be replaced if its capacity is below 80%of the manufacturer's rating. A capacity of 80% shows that thebattery rate of deterioration is increasing, even if there is amplecapacity to meet the load requirements.

Furthermore, the battery issized to meet the assumed duty cycle loads when the battery designcapacity reaches this 80% limit.Watts Bar -Unit 2 B 3.8-78(developmental)

AH Battery GeU-Parameters B 3.8.6BASESSURVEILLANCE REQUIREMENTS SR 3.8.6.7 (continued)

The Surveillance Frequency for this test is normally 60 months. Ifthe battery shows degradation, or if the battery has reached 85% ofits expected life and capacity is < 100% of the manufacturer's rating,the Surveillance Frequency is reduced to 12 months. However, ifthe battery shows no degradation but has reached 85% of itsexpected life, the Surveillance Frequency is only reduced to24 months for batteries that retain capacity

> 100% of themanufacturer's ratings.

Degradation is indicated, according toIEEE-450 (Ref. 2), when the battery capacity drops by more than 10%relative to its capacity on the previous performance test or when it is> 10% below the manufacturer's rating. These Frequencies areconsistent with the recommendations in IEEE-450 (Ref. 2).This SR is modified by a Note. The reason for the Note is to allowthe 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 toperform the function specified by this Surveillance for whichadequate documentation of the required performance isavailable; and2. Post corrective maintenance testing that requires performance ofthis Surveillance in order to restore the component toOPERABLE, provided the maintenance was required, orperformed in conjunction with maintenance required to maintainOPERABILITY or reliability.

REFERENCES

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

and Section 6,"Engineered Safety Features."

2.A XXX L A J IEEE 450t 1I39U.14995,

'ThL+/- ReocommA-Ondod P-raotico forB3attorio forF GonReating Statioew-and- Subc-htationsn-."IEEE Std 450-2002, "IEEE Recommended Practice for Maintenance, Testingand Replacement of Vented Lead -Acid Batteries forStationary Applications,"

Institute of Electrical and Electronics Engineers, Inc.3. IEEE Std 485-1983, "IEEE Recommended Practice for SizingLarge Lead Storage Batteries for Generating Stations andSubstations,"

The Institute of Electrical and Electronics Engineers, Inc.4. Watts Bar FSAR, Section 8, "Electric Power."Watts Bar -Unit 2(developmental)

B 3.8-79AH Battery GeU-Parameters B 3.8.6BASESWatts Bar -Unit 2(developmental)

B 3.8-80AH Contn"ment Penetratio-nSTHIS SECTION NOT USEDB 3.9.4B 3.9 REFUELING OPERATIONS B 3.9.4 Centainment PenetrAtionsTHIS SECTION NOT USEDDuring moGVRemen-t Of irra-d-iat-d-fuel1 aseble ithin con-t;4ainment, arelease of fisrsion product radioactivity within containment will be9 restricted from; escaping to the enViFronment WhenA the LCQ requiremnents are met.In MODES 1, 2, 3, and 4, thiG i6 accOMplichod by maintaining containment OPERABLE as described in LCGO 3.6.1, "Containment."

InMODE 6, the potential for con-tainmenA-t pressuriZation as a result Of anaccident is not likely; therefore, requirements to isolate the containment from the utsde atmosGphe-re can be9 loss Stringent.

The LCGOrequirements are referre~d to as, "contaRin.ment closure" ra;ther than;"containment OPERABILITY."

Containment closure mneans that al!potontiaI escape paths are closed Or capable of bein~g closed. Sincethere is no potential for co~tiAFnment pressurization, the Appendix jleakage criteria and tests are not required.

The- containm~ent 6orYes to contain fission product radioactivity that Maybe released froM the reactorF core follown an acident, such that offsiteradiation exposures are mnaintained well wthinR theA ire quir FeMenRts of10 CFR 100. Additionally, the containment provides radiation shieldingq from- the fission products that m~ay be pr9eset in the- containm.entA atmosphere following accident conditieons.

The containm~ent equipment hatch, which is part of the containment pressure bounder,,

provides-6

-A means for mo;ving lag eqimnt a;ndcomnponents into and ou t of containment.

During movLe.ment Of irradiated fuel assemblies within containment, the equipment hatch m~ust be hold inplace by at least four bolts. Good enginern pracItice dictates thaRt thebel1ts required by this LCO be approximately equally spaced.The containment air locks, which are also part Of the containment-pressure bGun~dar,,

provide a means for personnel access duFringMODES 1, 2, 3, and 4 unit oper-ation in accordancGe with LCOQ 3.6.2,"Containment Air Locks." Each air lock has a dIoor at both ends. Thedoors are nermally finterlocked to prevent simultaneu openig whencontainmen9t OPErRAR"I!T is required.

During Periods, of unit shutdon;s

.When conRtainment closure iS not required, the door in~terleck mnechanism may be disabled, allowing both doors Of an air lock to remnain open forextended periods when frequent centainment ont ,' is nesa. During(eo~ed)Watts Bar -Unit 2(developmental)

B 3.9-11AH Containment Penetratiens

-843.4BACKGROUND (G~eRt4~ed) mo-voment of irradiated fuol assemblies Within containment, containment closuro i6 required; therefor9e, the door may remairdieabed, u n wl~,dprr~M h aaeO 9fGh '-irm 't frtnt-imn nntitn erirdn.ir ht~releaeof fission prFoduc4t radioa4cvity Within will e re Ftfictedto within regulatory imnits.The BuildinRg urge Ventilation SyStemt operate.

to .u.pplyoutside aiMito the onanmn for venRtilation and cooling or heating, toequalize internal and external pressures, and to reduce the co-ncnmtr-ation Of noble gaseS Within containmenRt prior to and during personnel access.The supply and exhaust l"nes each contain Won isolation valves. Becwau seof their largqe 6, the 24 inch containm.on.

t l. O ,.r compatment pur.evalves are physically Frestricted to!!; 50 degrees open. The Ro-aceBuilding Purge and System can be opened inMODES 5 and 6, but are closed automatically by the EnRgineered SafetyFeat-ues.AcntuatioRn System (ESFAS).

In MODE 65, air exhangesare necessar-y o 9onduict refueling opeations.

The normal 24 inch purgesystem is used for this purpose.

The ventilation system mnust be eitherw solatod OFr capable of being automatically iselated upon detection of highradiation levels wi0thin containmient.

T-he o-ther coantainment penetrations that provide direct access froAmcontainment atmospher-e to outside atmosphere m~ust be isolate~d on Atleast one sidle. slto-a eahee ya PR.L uoaiisolation; valve, or by a maulioainvalve, blind flange, Or equivalent.

Eiale isoltiornor method s must be approved and may ilude use of amaterial that can provide a temprary, atmospheric

pressure, ventilation brirfo-r the ether containmenRt penetrations during fuel moGv8emets (Ref. 1). ClOsure by ether valves Or blind flanges may be used if they aresimilar in capability to those provided for containment irsolation.

T-heseAm;ay be conStructed of standardI materials and may be justified on thebasis of eithe-r nor-mal an;alycis methods or reasonable engineern judgment (Ref. 4).A P PLIC GABL e IDuring movement of irradiated fuel as-se-mblierbmswihn cnanet theSAFETYmost severe radielegical consequences result fromR a fuel handlingANIALYSý accident.

The fuelA- handling acc~ident is a postulated event that involvesdamage to irradiated fuel (Ref. 2). Fuel handling accidents, Inayzed iRe-feqrence-R

-2, include drogpping a single irradated fuel assembly-and-handling tool Or a heavy ebject onto other irradiated-fuel assrem~blies.

Watts Bar Unit 2B 6onta'AInmon Pdonotra!ions 84.44BASES.APPLI'C-A

'BLERA F;EmTYLThe requ-eirements of LCOQ 3.9.7, "Refueling Cavity Water Level," inconjunction With a minimumu~

decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to irradiated ful-- moVe-men-t-with c-ontainmenRt closuF9recapability en;SureS that therlAse f flss*on product ra;dnioactivity, subeGu~ent to A fue h ndlingacciden~t, results in doese that are well within the guideline Yaluespecified in 10 CER 100. Standard RevieW Plan, Section 16.7.4, Rev. 1(Ref. 3), defines "well within" 10 CFR 100 to bhe- :25% or loss- of the10- C-FR 100 val-uesr.

Thie acceptanco limitS for offitot radiation exposuree will be 25%0 of 10Q CErR 100 values or the NRC staff approved iesgbaums IR n~. ra seecifd frac;tion o~f 10 CPR 100Q limit)Containent peetrat*Gons sat*f' Criterion 3 of the NRC PolicyStatemelt.

Thist LG HFl kst~ the rsnseRWnAtncnf ef a fiuel handlin, arrident in....-4-f- r...A.l .,..radioactivity released WithiR contanment.

The LCQO requieres any-penetration pro9viding direct accGss fromn the GgntainM9nt atmos~phere tethe outside atmoGsphere to be closed eXcept for the OPERA\BLE ReactorBuilding Purge and Ventilation System penetrations, and the containme.t personnel a*Fle.k..

ForF the-A OPEZR.BLE Building Purge andVen-ti--rla-t System penetration, this LC ensures that thesepenetrations

-are- isowl-able by the Containment Ventilation

!solati~ln SystemA.+Re WIIKJE !I=-+ r ogiumn r LflIS LGO enswer thati the autematpurge and exhaust v-alve- closuire tie6pecifed in the F=S.AR can beanchieved-and, therefore9, meeqAt the- asmtosused

~nthe safety-analysis to e-nsu--re t-ha-;t rlae th-rough the valves are terminated, SUchthat radielogical doses are within the acceptance limit.The Gontainment personnel air'oock doors may be open during movemnent of irrFadiated fuel iR the Ggntainment providted-tha-t onRe deer is capable ofbeing closed- in the event of A fuel hanRdl~ing acciden~t an~d provided thatABT is OPERA~VBLE OR accoruanco With TS~ 3.7.12. Should a 'ehandling accident occGur inside contaiment, one personnel airlock doerwill be closed foallowing an eyacuation of contaiment.

The LCO ismedified by a NoAte- all-owing penetration flew paths with direct -accessfromA the Geontainment atmorsphere to the outside atmosphere tobunisolate-d iunderB admnitraivGcotrls Admninistrative controls ensurethat 1) appropriate personnel are aware of the open status of the-penetration flow path durin movmet of irrad-iated-fuelA- ýassemblies WONR GGRtaiR ent: 21 SmeGified ORdiy4duals aFe de6k]Rated aRd readliv(GGRtieWd)

WAaft Bar Unit 2A 69MenaIRnmOn Pd8netrzuionR B 3.94BASES8L-Go3) ponotration flow paths, penetrating the Auxiliary Building Socondar,'

(G94Rtued)

Containment Enclos6uro (ABSCE=)

boundar-y, are limited to less than the" bmroch allOWaRnc; ard 4) the ABGTS is OPERA.Er inaCCordance wi;th TS- 3-7.12. Operability of A1BGTS- is required to ,alleviate the consequences of an FHA insi~de containment resUlting in leakage Ofairborne Fadieoancive matei~wal past the open airlock Or penetration flowpathsG prior to their closu re-..APPLI[C-AB-ILITY The containm~ent penetration requiremnents are applicable duringmov'ement of irradiatod fu-1e assemblies wthin containment because thisis whern there i,- a potential for the fuel haRdling accide-nt.

InMODES 1, 2, 3, and 4, containmenRt penetration requiremnents are-addressed by LCO 3.6.1. In MODES 5 and 6, when movement of-irradatedfuelassemlieswithn cotainment is net bein~g conducted, thepotential for a fuel handling accident nRt exist. Therefore, underthese condition no equremets are placed On; containm~ent penetration 6tatu6.If the- con-ta-inment equipmen~t h~atch, air locks, or an" cntainm~ent penetration that provides direct access from the containment atmosphere to the outside atmosph~ere 16 net in the required status, including theCon-t~ainmen-t VenRtilation Isolatian System net capable of automaiataion hen the purge and exhaust valves are open, the unit mRust beplaced in a GenditiGR where the isolation fucinis nt needed. This isaccomplished by immediately suspending movement of iF~adiatod fuelassem~blies wIAthiN conA-t-ainment.

Performance of these acin hall notpreclude com~pletion of mevement of a comAponent to a safe PGsit*Gn.

SURVEILL\ANCE R-3.44REQUIREMENTS This Sur~eillanca demonsRtrates that each of the containment penetrations required to be in it closed position is in that position.

The Survoillance on the open purge and exhaust valves will demonstrate that the valves,are not bloc-ked frm.-m closing.

Also the Survoillanco will demon~strate thateach valve operatorF moFtiVe PoweF, which will ensure that each valveis capable of being closed by an O-PERA.LR utemWAce nventRilationisoatosinl Wl;tts Bar UJnit 2(dy 0GmntlB 3.9 44A Containment Penetrations B 3.9.4BASESSUR VI:E I AL'lrC QF SR 3.9.1.1 (continued)

REQU REMENTSa.,a,7 Ai A. re Cl.. ^fa -nnnra,a 00 rMv WIrcp cx-ro or H EMULI! -- .... A--! ....irra a aite e T... .. A .M. I. ..w itn In c o n TAin m .. .. ...ntIll II iJselepLed

$t ht; commenlirtef with the normal 911Fulrn or f!m9 tot1I P II I acomnplete fuel handling operations.

A sur~lllanco before theo start ofrefueling operations will provide two or three sUrYoilIRARc Verifications during the applicable period forF this; LCO. As sucoh, this Surveillance ensures that a postulated fuel handling accident that releases fissionproduct radioactivity within the containm~ent Will not reSUlt ina release ofsignificant fis6ion product radio~Acivity to the enViFromen~t in exos 9fthosbe reconmmenR8ded by Standard ReViewM PlanM Section 15.7.4 (Ref. 3).This Surveillanc~e demonstates that each containmenAt purge and exhaustvalve actuates to its isolation position on mnanual initiation Or On an actualor simulated high radiation signal. The 18 mRonth FrequencY m~aintains consistency With ether similar ESFAS itrmnaonand valve testingrequirem~ents.

LCGO 3.3.6, "Containm~ent Ventilation Isolation; Instrumentation,"

requires a CHANNEL CHECGK ever' 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and aCOT- ever,' 92 days to ensrWe the channel O)PERABILITV durling refueling operations.

EvYer' 18 mon9ths, a CHANNELI CALIBRATION is pe~fGFmed.

The soystem actuation reGponse time isdmntaed ever 18 months,dur~ing refueling, On a STAGGERED TEST BASIS. SR 3.65.3.4de~monstratews that the i~solation time of each valve is in; accordRance Withthe Inser~ice Testing Prora requrents.

These Survellancos peofermed during MODE 6 w.~ill nsr that the valves are capable ofclesing a#fte a postulated fuel handl'ing accidenRt to limtarelas offissio.'n oroduct radioactivity from the GGntainment.

4,;"Us F;e o-f S~iliconGe Sealant to Maintain Con(9taRinmen9t lntegrity ITS.May 20, 98&-Watts Ba;r FSAR, Section 15.4.5, "Fuel H4andling Accident.

NUREG 0800, Standard Review Plan, Section; 15.7.4. "Radolpeica 4-.Lonsnuenes f Ruel Hanclino Acci-dents:

Keyv. I. Juiv I MI.UIGeneric Loller 88 17. "Loss of Decay Heat Removal."

WAtt~s Bar Unit 2a Refueling Cavity Water LevelB 3.9.7B 3.9 REFUELING OPERATIONS B 3.9.7 Refueling Cavity Water LevelBASESBACKGROUND The movement of irradiated fuel assemblies within containment requires aminimum water level of 23 ft above the top of the reactor vessel flange.During refueling, this maintains sufficient water level in the containment, refueling canal, fuel transfer canal, refueling cavity, and spent fuel pool.Sufficient water is necessary to retain iodine fission product activity in thewater in the event of a fuel handling accident (Refs. 1 and 25). Sufficient iodine activity would be retained to limit offsite doses from the accident to-25%0 of 1 0 CFR 100 limits, as proVided by the guidance ofRtfeie--

the limits defined in 10 CFR 50.67 (Ref. 4) andRegulatory Position C.4.4 of Regulatory Guide 1.183 (Ref. 5).APPLICABLE SAFETYANALYSESDuring movement of irradiated fuel assemblies, the water level in therefueling canal and the refueling cavity is an initial condition designparameter in the analysis of a fuel handling accident in containment,-ae-postulated by Regulato.y Guide 1.25 (Ref. 1). A minimum water level of23 ft (Regulatory Position G-,---2 of Ref-4Appendix B to Regulatory Guide 1.183) allows an overall iodinea decontamination factor of40-200 (Regulatory Position G.1.9. of Ref. 1) to be used in the accidentanalysis fGF iedine. This relates to the assumption that 99% of the totaliodine released from the pellet to cladding gap of all the dropped fuelassembly rods is retained by the refueling cavity water. The fuel pellet tocladding gap is assumed to contain 8% of the 1-131, 10% of the Kr-85,and 5% of the other noble gases and iodines from the total fissionproduct inventory in accordance with Regulatory Position ofRegulatory Guide 1.183total fuel red iodine ine'ntory (Ref. 1) exGcpt for1134 Which is assumed to be 12% (Ref. 6).The fuel handling accident analysis inside containment is described inReference

21. With a minimum water level of 23 ft and a minimum decaytime of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to fuel handling, the analysis and test programsdemonstrate that the iodine release due to a postulated fuel handlingaccident is adequately captured by the water and offsite doses aremaintained within allowable limits (Refs. 4 and 5).Refueling cavity water level satisfies Criterion 2 of the NRC PolicyStatement.

(continued)

Watts Bar -Unit 2(developmental)

B 3.9-20AH Refueling Cavity Water LevelB 3.9.7BASES (continued)

LCOA minimum refueling cavity water level of 23 ft above the reactor vesselflange is required to ensure that the radiological consequences of apostulated fuel handling accident inside containment are withinacceptable limits, as provided by the guidance of Reference 32.APPLICABILITY LCO 3.9.7 is applicable when moving irradiated fuel assemblies withincontainment.

The LCO minimizes the possibility of a fuel handlingaccident in containment that is beyond the assumptions of the safetyanalysis.

If irradiated fuel assemblies are not present in containment, there can be no significant radioactivity release as a result of a postulated fuel handling accident.

Requirements for fuel handling accidents in thespent fuel pool are covered by LCO 3.7.13, "Fuel Storage Pool WaterLevel."ACTIONSA.1With a water level of < 23 ft above the top of the reactor vessel flange, alloperations involving movement of irradiated fuel assemblies within thecontainment shall be suspended immediately to ensure that a fuelhandling accident cannot occur. The suspension of fuel movement shallnot preclude completion of movement of a component to a safe position.

A.2In addition to immediately suspending movement of irradiated fuel,actions to restore refueling cavity water level must be initiated immediately.

SURVEILLANCE REQUIREMENTS SR 3.9.7.1Verification of a minimum water level of 23 ft above the top of the reactorvessel flange ensures that the design basis for the analysis of thepostulated fuel handling accident during refueling operations is met.Water at the required level above the top of the reactor vessel flangelimits the consequences of damaged fuel rods that are postulated toresult from a fuel handling accident inside containment (Ref. 21).The Frequency of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is based on engineering judgment and isconsidered adequate in view of the large volume of water and the normalprocedural controls of valve positions, which make significant unplanned level changes unlikely.

(continued)

Watts Bar -Unit 2(developmental)

B 3.9-21AH Refueling Cavity Water LevelB 3.9.7BASES (continued)

REFERENCES i I I IRegulator:

Guide 1.25, "Aceump~tIOnS Used tor Eyalwatlneivme li*i_

/'%WAeTenTIa

-~Al iicia -GRceciU6REcv 8+ a IrUe I 01RzIno-RIAnt.

.ociuoit in the; Fuoal andhng and Soag Faclty for Boiling andProessurizoed-Water ReactoFrs,"

U.S. Nucloar Rogulator,'

Commission, March 23, 197-2-.21. Watts Bar FSAR, Section 15.4.5, "Fuel Handling Accident."

32. NUREG-0800, "Standard Review Plan," Section 15.7.4,"Radiological Consequences of Fuel-Handling Accidents,"

U.S. Nuclear Regulatory Commission.

43. Title 10, Code of Federal Regulations, Part 20.1201 (a), (a)(1),and (2)(2), "Occupational Dose Limits for Adults."-o" "tj ft , ..1 tp , ..1 " ", ., am t;Vt7C2"tV-,-a-.,

JAI~ ni~. I~aeio~oaicai uoncoouencoc OT a i-uoi ~ano~ina5g.Accident, December 197!.Title 10, Code of Federal Regulations, 10 CFR 50.67, Accident Source Term."NURE&GCR 5000, "Assessiment of the UIS-3 Of EXtend8d BuFRnUPFuel in Light Water PoWer Reactors,"

U. S. Nuclear Regulatory Commission, Februarjy 1g8.Regulatory Guide 1.183, "Alternate Source Terms for Evaluation Design Basis Accidents atNuclear Power Reactors,"

July 2000.Watts Bar -Unit 2(developmental)

B 3.9-22AH ReacztorF Buildine Purgne A~ir Cle-anu44UtsTHIS SECTION NOT USEDB 3.9.8B 3.9 REFUELING OPERATIONS B 3.9.8 Reactor Building Purge A.i Cleanup UnWt THIS SECTION NOT USEDBASESThe4 Reactor Building Purge Air Cleanup Units are aenierdsafet feature of the Reactor Building Purg8 Venltilation System hih snoR Safety feature VentilatioR SY-t-m. The ai-r cleaRup unit containprefiltw"s, HEPA filters, 2 inch thick charcoal ador{brS, hous'ings andductwork.

Anytime fuel handling oper-ations are being carried an insidethe primnary containm~ent, either the containment Ventilation Will be-isolated Or the Reactor Building Purgo air cleanup units Will beOPERA.BLE (Ref. 1).The Reactor Bufilding Purge Ventilation SystemR provide6 mechanical Yentilation of the prim~ary con~tainm~ent, the instrum~ent room located withinthe containment, and the ann-dulu.

The4 systemn i6 designed to Supplyfresh air forF breathing and contamination controel to allow pFersonne acGc6s for mainateRane and refue~ing operation6s--

Th.e aust air isfiltered by the Reactor Building Purge Air Ceanup Unitsm to limit therelease of radio~activity to the enviF4ronment.

The conRtainmqent upper and lower G9ompa~tments aro purged with fresh airby the Reactor Building Purge Ventilation System before oc.upancy.

Theannu.u. can be purged with fresh air during reactor sh.utdowR or at times::hen the annUIUS vacuumn cOntro systemA of the EmRergency Gas-Treatmfent System is shut down. The instrumont roo is purgd withfr61;h air d.ruring operation of the, Reaor,,,,

Building Purge Ventilation System Or *i separatey purged by the InRstFrument Roo PurgeSubsystem..

All purge ventilation are non Safety relatetdThe Reazicwr ounuInoR Pdurue Ventiiaugn OYStoM 1s SiZefg 1o DrOVIGOI *

  • i II *iadequate ventilation Tor personnei to ponrmFF Wor~ nsiao the pr ImrcontaiRnment and the annulus during al! normal eperatiens.

In the even9-t Ofa fuel handling the Reacrto BuildiRn Purge VenIl;atio SysteM *ii solated.

The Reactor Building Purge Air Cleanup Units are always-available as passive i,;nline to peOFrm their functionimmwnediately after a fuel handling acciden.

t to process activity exhaust air before it reaches the outsid-e enAvironenMGt.

kGwniped)

Watts Bar -Unit 2(developmental)

B 3.9-27AH I Wt1eactor WWF96in Aure Gler~iaRUp) un4133.9.9RASESBACKGROUND The PrFinmar containment oxhaust is monitorted by a radiation deteGtor(G9RtiRued)

Which provides c contai- n nment pruge olatinupon detocting the sotpoinRt randio;activty Rn the exhaust air streamR.

Thecnonntainment purge VSnt;ilation n vialvyes

, Will bhO automIGAticOally clGoedup'n the actuation of a Vent lon (\II\ (GVI) .ignal the ontainnment is being purged during RFnoral operfiWn or uponmanual actut iotn from tho Main CnCtrol Room (Ref. 2). Requirements for CntOnmen Ret Vent lme÷ation Instrumentation are oevered by ICnO 3.3.6.APPLICABL P The Reactor Building Purge Vertilation System,; Goaup units ensrureSAFETY+ that the rl of to the eAnviFronment is limited by ineanihig Up G\ntainment exhaust during a fuel handling acmident befor FhecontaiRnment purge exhaust valvesb arse isolated.

Reactor Building PurgeVoni÷aio lSystemr filter effichi on,-6 Gne Of the inputs for the analysis ofthe envro;Gnmental consequences6 of a fuel handling accident.

Containment isolation can only result in smnaller releases of radioactivity to theon men oAiG t (Ref. i1o The Gontainmnt VeRnt Isolation SystemAnsures that the containment vent ,and purge peRetrationR will bautomatically isolated upon detection of high radiation levels within thecontaiF;nment (Ref. 2). Containment Vent Isol-ation Iruettini address~ed by LCO 3.3.6.The Reactor Building Purge Air Cleanup Un~its satisfy' Criterion 3 Of theNRC Policy Statement.

In addition, during moGv9emet of irradiated fuel in the Auxiliar-y BuildigWheR contaiRnment iS open to the Auxiliary Building

spacses, a hig-hradiation signal fro-m the- spent fuel peol acciden~t radiation monitors

, aConAtainm.enAt Isolation Phase A (SI sign~al) frogm the oporating unit, hightemRperature in; the Auxiliary Building air intakes, or manul ABI wil initia;te a CVI. In the case where the cOntaiRnmenAt.

of. botFuitS is open to theAuxiliary Building spaces, a CVI in one unit Will initiate a CVI in the otheruiinord-er to.m.aintain those spaces open to the ABSCEF.The safety func~tion of the Reactor Bui4lding Purge Air Cleanu1p Unit isrelated to the initia! contre! o-f oF.t raito xoures resulting

  1. fro afuel handling accident insido GGGntainmnt Duig a fuel hand~ling accient nsie ntainment, the Reactor Building Purge Air Cleanup Unitprovides a filtered path forF clean~ing up any air leaYing the containment un-til the cneptainment ventilationilioatdBr Unit 2(dvlopmetl)

--a-toFr IiI-d*RQ UFIrq A lAOF (;'GaRUP IJ133.9.8LGQ(Ge4Rued)

The plant design i,-; s that WhBnA moing irradiated fuel in theA uxi'iar' Building o~!FG1tiMFtWiht9G~aR~~

pen theAwmvia,-

Building A S ,

I m the -pen fu.l 0 RE 90 102 and 103 Will initiate a CVI in addition to theirnorFm-Al funcRAtion.

In aRddi@tion, a 6ignal frmthe coentiainmFent purge radiation 2 RE( 9(0 130, and 1 3 r OFthr CIVI -ignal Will iRitiate thatpllin of the AB-RI normally initiated by the spent fuel pool radiati omonitors.

A~dditionally, a CnametIotinPhase A (SI signal) fromthe operatinRg unit, high temnperature in the Aumiliari Building airinaksor manual ABI1 will cause a CVI signal inR the refueling unit. T-hereforFe, thecontainment

-ventoiation instrumentatlon mustt remain operable whenmoing, irr-adiated fuel in the uildiRng if the c-ntainFmen t penetrations, equipmfent hatch, etc. are open to the Auxiliary BuildingABSCE= spaces. In addition, the ABGTS must remain operable if theseconRtain.mnt penetrations are open to the Auxiliary Building durng,@movement of iFradiated fuel in side conAtainmenAt.

In the case where thecontaiRnment of both units is open; to the Auxiliary Buildingq spaces, a CVIin one- 'unit Will initiatte a C-VI in the_ o-therF unit in order to minai thoseqspaceG open to the ABSCE.APPLICABILIT An initial assumption in the analysis of a fuel handling accident isd that the taccidet occus whileat hdhandletd_.

Therefore, LCO 3.9.8 is applicable only at thiS ti~m~e. seead-dition~al discussionr_,(9 in the Applicable Safety Analysis and L=,CO sections.

AGT-IONS

_.Ia~ .if one Roaster Building Purge Air Cleanup Unit is ineperable, that airceanup unit m.us;t bhe islated.

This places the system in the requiredaccident thus allowing refueling to r-antinue afer- erifyingthe eminn air cleanup unit Is aligned and OPERABLE.

The imeit ompletion T-ime is consistAnt With the required times, fonractions to be pe~fermed without delay and in a con~troalled mannr.WAI-+s Bar UnIt 2(dove lopme ntal)B 3.929GI M A 1 AII i tLReactor tiuMidin l-'urg Air Cleanup Wnt1349.8ACTIONS(GGetRued) 984WiAth tWon Re-actor Building Purge Air Cloanup Units inoperable, MoQVomo;nt o9f iraitdfuel assemblies_

wIAthin conQtainm~ent mAust b9 suspended.

This prec'udes the possibility of a fuel han~d!ing accident in cOntaiRnment

.. ith both ReActor Bu ilding Purge AiF Cloanup Unitsinprbe Performa~nce of ths cion shall noGt preclud9 moInG l omoent to asafe peste;*rThe immediate Completion Time is consistent With the required times forFactAions, to bhe performned without delay and in a controlled m4annrS'JRVEILLANICE RR34REQU IREMENTSThe_

Filter Tes-ting ProgrFam (VF\TDP) the Building Purge Air Cleanup Unit filter tests in accordance with Regulatory' Guide 1.52 (Ref. 3). The VFTP includes testing the performance of theHEPA filter, charco-al

-adeorbsrer efficiency, miiu .f.lew rate, and thephysical prope~tios of the actiyated charcoal.

Specific test rFreqecsand aditinal nfor at~nae discussed in detail in t-heA VFRTP.REFERE- CE 4,~ W~ats Bar FSAR, Section 15.5.6, "Einvironmental Consoquencos Ofa Postulated FuelA_ Hand-ling Accident."

2- Watts Bar FSAR, Section 0.4.6, "Reactor Building Purge Ventilat~ing system.3, Regulatory Guide 1.52 (Rev. 02), "IDesign, T-esting and-Maintenan

.Criteria for Pest AGccdent Engineered Safety FeatureAtmesphere l.ean.p System A;r rFltration and Adsorptieon Units ofLight Water Cooled Nuclear Power Plants."IAIAtts Bar Unit 2R 29-30A Decay Time3.9.10B 3.9 REFUELING OPERATIONS B 3.9.10 Decay TimeBASESBACKGROUND Section 15.5.6 of the Watts Bar FSAR (Ref. 1) defines theassumptions of the fuel handling accident radiological

analysis, including a minimum decay time for irradiated fuel assemblies priorto movement.

This assumption ensures that the inventory ofradioactive isotopes is at a level that supports the safety analysisassumptions.

To ensure that irradiated fuel assemblies have decayed for theappropriate period of time, a limitation is established to require thereactor core to be subcritical for a time period at least equivalent tothe minimum decay time assumption in the fuel handling analysisprior to allowing irradiated fuel to be moved.Given that no irradiated fuel assembly will be moved outside of thecontainment until the minimum decay time requirement is met, thisrequirement also ensures that any irradiated fuel assemblies thatare moved outside of the containment meet the decay timeassumption in the radiological analysis of the fuel handlingaccident.

APPLICABLE SAFETYANALYSESThe radiological analysis of the fuel handling accident (Ref. 1)assumes a minimum decay time prior to movement of irradiated fuelassemblies.

The requirements of LCO 3.3.7, "Control RoomEmergency Ventilation System (CREVS) Actuation Instrumentation,"

LCO 3.7.10, "Control Room Emergency Ventilation System(CREVS),"

LCO 3.7.11, "Control Room Emergency Air Temperature Control System (CREATCS),"

and LCO 3.9.7, "Refueling CavityWater Level," in conjunction with a minimum decay time of 100hours prior to irradiated fuel movement ensures that the release offission product radioactivity, subsequent to a fuel handling

accident, results in doses that are within the requirements of 10 CFR 50.67(Ref. 2) and Regulatory Position C.4.4 of Regulatory Guide 1.183(Ref. 3).The decay time satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

(continued)

Watts Bar -Unit 2 B 3.9-26Technical Requirements (developmental)

H Decay Time3.9.10BASES (continued)

LCOA minimum decay time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> is required prior to movingirradiated fuel assemblies within containment.

This preserves anassumption in the fuel handling accident analysis (Ref. 1), andensures that the radiological consequences of a postulated fuelhandling accident inside containment are within acceptable limits.APPLICABILITY This LCO applies during movement of irradiated fuel assemblies within the containment, since the potential for a release of fissionproducts exists.ACTIONSA.1When the initial conditions for prevention of an accident cannot bemet, steps should be taken to preclude the accident from occurring.

When the reactor is subcritical for < 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, movement ofirradiated fuel assemblies within containment must be suspended.

This action precludes the possibility of a fuel handling accident incontainment.

This action does not preclude moving a fuel assemblyto a safe position.

The immediate Completion Time is consistent with the requiredtimes for actions to be performed without delay and in a controlled manner.SURVEILLANCE REQUIREMENTS TSR 3.9.10.1This SR verifies that the reactor has been subcritical for at least100 hours prior to moving irradiated fuel assemblies by confirming the date and time of subcriticality.

This ensures that any irradiated fuel assemblies have decayed for at least 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior tomovement.

The Frequency of "Prior to movement of irradiated fuelin the containment" is appropriate, because it ensures that thedecay time requirement has been met just prior to moving theirradiated fuel.(continued)

Watts Bar -Unit 2 B 3.9-27Technical Requirements (developmental)

H Decay TimeB 3.9.10BASES (continued)

REFERENCES

1. Watts Bar FSAR, Section 15.5.6, "Environmental Consequences of a Postulated Fuel Handling Accident."
2. Title 10, Code of Federal Regulations, 10 CFR 50.67, "Accident Source Term."Watts Bar -Unit 2 B 3.9-28Technical Requirements (developmental)

H ATTACHMENT 3WBN Unit 2 TS and TSB Developmental Revision H(Optical Media Storage)

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