ML18033A177

Proposed Revised Tech Specs,Implementing Recommendations of Generic Ltr 84-15, Proposed Staff Actions to Improve & Maintain Diesel Generator Reliability.

ML18033A177
Person / Time
Site:	Browns Ferry
Issue date:	04/13/1988
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18033A176	List: ML18033A174 ML18033A177
References
GL-84-15, TAC-00092, TAC-00093, TAC-00094, TAC-92, TAC-93, TAC-94, NUDOCS 8804210027
Download: ML18033A177 (22)

Text

LIYITIHG CONDITIONS FOR'OPERA IOK SURVEILIAN L RR:,>JICcFP5LIc.S 3.9.B.eratlon w2th Ino erable~au1 ment~Whenever the reactor 2:s'n Startup mode or Run mode anc2*not in a cold condition, the availability of electric power shall be as specified in 3.9.A except as specified herein.-1.From and after the date that only one offsite power source is available, reactor operation is permissible for 7 days.4.9.B.O~ierat1on

<<'2th In~cd>c chttlc Rgu2 pmcecct 1.When only one of f site power.source.is OPERABLE, al 1 units 1 and 2 diesel generators

~2., From and after the date that the 4-kV bus tie board becomes INOPERABLE, reactor operation is permissible indefinitely provided one of the required offsite power sources is not supplied from the 161;kV system through the bus tie board.must be demonstrated to.~ed-4~~thereafter.

2..-when a required offsite power source is unavailable to unit 1 because the 4-kV bus tie board or-a start bus is INOPERABLE, all unit 1 and 2.diesel generators

~shall be demonstrated OPERABLE thereafter.

The remaining offsite source and associated buses shall be.checked to be energized daily.88042i0027 880%is PDR ADOCK 05000259 P DCD BFN Unit 1 3.9/C.g-e

~I l'~

LIP.'I.INU COt4:>'..I e)M'.: POi.Oi'EitS.'Ol'UR'L'Ll't', RE@'v'IRENE!Ž~'pera', for: I:I tt.Ino et at le eius ment Wheti one of the units)and 2 diesel.aerierator is-INOPERhBLL', cOttt inued reactor-oper'at.ion is permissible during the succeeding 7 aays.provided that 2 offsite power.sources are avai I table as speci f1ed in 3.9.J.l.c and all of'he CS..RHR (LPCI and containment cool ing)systems.and the remaining three units 1 and 2 diesel generators are OPERAB'.If this'requirement.cannot be met, an orderly shutdown shall be initiated and the reactor shall be shut down and in, the cold condition with1n 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.eel I.b I.~L.0>er a t.lot.Wi t ti Ino er able EcCu!>e en'tier.ot>e o.'he un1ts 1 arid"'iesel generators

'is.f ound.to'be INOPERABLE

~.all of tlie~-RHR.remaining diesel'generators

~'hal'1 be" demonstrated to be thereafter.

When one units 1 and 2 4-kV shutdown board is INOPERABLE.

continued reactor operation is permissible for a period of 5 days provided that 2 offsi.te"power sources are.avai:lable as specified in 3.9.A.l.c and the remaining 4-kV'hutdown boards and associated diesel'enerators, CS, RHP.(LPCI and-containment cooling)systems, and all 480-V emergency, power boards, are OPERABLE.If this requirement cannot be met, an orderly shutdown shall be 1nitiated and the reactor shall be shut.down and in the cold condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.ei Pre r'i 4.When one 4-kV shutdown board is found to be INOPERABLE, all generators~~d

-'he remaining 4-kV shutdown boards shall be demonstrated to be thereafter.

e BPN Unit 1 3.9/4.9-9 11 l S

'Y~~IHC COND'Ol" FOi.OPEke".10t': SURVEILLANE L kE~>ul kHPtEt".":'.9.B.

0ier'at.ion With lnor>erabl

<<'Eau1 meri: t"hen on<<of the nutdovm buses's INOPERi.BLE, reactor operation'is permissible for a period of 7 days'.*C.S.B.Q>iet at1on.with in~oeralilc EcCul men1 4'h<<lE 8 shut 4~i bu.'.found to bt.1HOPL'BABLE, a11 1 and 2 diesel generators shall be proven OPERABLE u 6.When one of the 480-V.diesel auxiliary board" becomes INOPERABLE, reactor operation is permissible for a period of.5 days.7.From and after the date that one of the three 250-V unit batte'ries and/or its associated battery board is found to be INOPERABLE for any reason, continued reactor operation is permissible during the succeeding 7 days..Except for.routine surveillance testing.NRC shall be notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the situation,,the precautions to be taken d'uring this period, and the plans'o return the failed component to an OPERABLE-state.6.When one-units-1 and 2 diesel auxiliary board.is found to be.INOPERABLE,~each unit 1 and 2 diesel generator shall be proven-.OPERABLE-da4+y-thereafter.

2./I+~ra~~~~g.~t('g~'BFN Vnit 1 3.9/4.9-10

~I 3.9/4.9 AUXILIARY ELECTRICAL SYSTEM LIMITING CONDITIONS POR OPERATION SURVEILULNCE.REQUIREMENTS 3.9.8.0 eration with Ino erable E~ui ment 4.9.B.0 eration with Ino erable~nut ment Whenever the reactor is in STARTUP mode or RUN mode and.not in a cold condition, the-*availability of electric power shall be as specified in 3.9.A except as specified herein.1.Prom.and after the date that only one offsite power source is available,'reactor operation is permissible for 7 days.When only one offsite power source is OPERABLE, all units 1 and 2 diesel generators and-must be demonstrated to wndM~thereafter.

2.From and after the date that the 4-kV bus tie board becomes INOPERABLE, reactor operation is permissible indefinitely provided one of the=required offsite power sources is not supplied from the 161-kV system through the bus tie board.2.When a required offsite power source is unavailable to unit 1 because the 4-kV bus tie board or a start bus is INOPERABLE, all unit 1 and 2 diesel generators nnd-shall be demonstrated OPERABLE thereafter.

=The remaining offsite source and associated buses shall be checked to'be energized daily.4l MW AW~3FN~t m'n.".3/4.3-3 1'll LIj.Ylhk COj'D'ON"..POF OPERh.IOt,.3.9.8..erat Ionh Irido ierab)e etraui ment GtJRVEILLZ N E.REPJIRE>~~.".

4.9.B.0 e.at 1ont.with Irido er abl c ettEu1 ment 3.4~linen one.of the units 1 and'.di<<sel ge>>er'ator is INOPERAULL,.continued reactor operation's permissible during the succeeding 7 days, provided that 2 offsite powe'r sources are available as specified in 3t9.A.l.c and all of the CS, RHR (LPCI and-containment cooling)systems, and the remaining three units I'and 2 diesel-'enerat'ors are OPERABLE.If this requirement cannot be met, an orderly shutdown shall be 1nitiate'd and the reactor shall be shut down and in the'old condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.When one units 1 and 2 4-kV shutdown board is INOPERABLE, continued reactor operation is ,permissMle for a period of 5 days provided that 2 offsite power sources are available as specified in 3.9.A.l.c and the remaining 4-kV shutdown boards and associated diesel generators, CS, RHR (LPCI and conta1nment coo11ng)systems, and all 480-V emergency power boards are OPERABLE.If this requ1rement cannot be met, an orderly shutdown shall be init1ated=

and the reacto.shall, be shut down and 1n the cold condition within 24 hou.s.3.When one of the units I and 2 diesel generators i"" found to be INOPERABLE, all of the W~jHR--remaining diesel generators end-s;hall be demonstrated to be, thereafter.

~S r/'~1/A~g~~~4.'"When one 4-kV shutdown board is found to be INOPERABLE, all the remaining 4-kV shutdown boards shall be demonstrated to be 2.4~~~./Q generators~s

-,<rnd-e~I 4t/M~~BPN Unit 2 3.9/4.9-9 AU>:":hP.'

EeeŽI."h'SŽE"'IMNI, INGe CORDI IONG" POP.OPERAŽION SURVEIL~6 REQUIRENEh S 3.9'.B.0'eration With Ino crab]e~Eui'ent 4.9.S.0 erat ion With Ino~erahle

~Eu1 ment.5.When one of the.shutdown buses ls INOPERABLC, reactor operat'ion is permissible for a period" of l days.5.When a shutd~bus is found to be INOPERABLE.

all'and 2 diesel.generators.

shall be proven OPERABLE 6;-When one of the 480-V diesel auxiliary boards becomes INOPERABLE, reactor operation is permissible for a period of 5 days When one units l and 2'diesel auxiliary board is found to be INOPERABLEe.

Che each-unit 1 and 2 diesel generator shall be proven OPERABLE i 7.Prom and after the date that one of the three 250-V unit batteries and/or its asso'elated battery board is found to be INOPERABLE for any reason'.continued reactor operation is permissible during the succeeding 7 days..Except for routine.surveillance testing, NRC shall be notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.of the situation, the precautions to be taken during this period, and the plans to'return the failed component to an OPERABLE state d ekko thereafter.

nM4'4~m~y~~BPN Unit 2 3.9/4.9-10 V'I f'

.9/4.9 AUXILIARY ELECTRICAL SYSTEM LIMITISG CONDITIONS FOR OPERATION SURVEIl LANCE.REQUIREMENTS 3.9.B.0 eration with Ino erable~Eui.ment 4.9.B.0 eration with Ino erable~Eut ment Whenever the reactor is.in, STARTUP mode or RUN mode and not in'a Cold-Condition.

the availability of electric power shall be as specified in 3.9.A except as specified herein.l.'From and.after the date that only one offsite power.source is available, reactor operation is permissible under this condition for seven days.1.When only one offsite po~er source is OPERABLE, all unit 3 diesel generators

~must be demonstrated to be OPERABLE-4a44y thereafter.

When one unit 3 diesel generator (3A;3B, 3C, or 3D)is INOPERABLE, continued reactor operation is permissible during the succeeding 7 days, provided that two offsite power sources are available as specified in 3.9.A.l.c.

and all of the CS, RHR (LPCI and containment cooling)systems, and the remaining thr'ee unit 3 diesel generators are OPERABLE If this require-.ment cannot be met, an orderly shutdown shall be initiated and the reactor shall be.shut down and i.n the Cold Condition within~24 hours.2.When one unit 3 diesel generator is found to be=INOPERABLE, all of the remai.ning unit 3 diesel generators.

end-shall be demonstrated to be OPERABLE-aac~4+y thereafter.

g,F A l~

C}/g 0 t'mum'tuye

~mApq Et E~keCAe t yc TE~e/e LIMNI INC CONDŽ10ldS POk OPERAT10N e SUk VE I LLANO L-k EQU I R EVENTS 3.9.B.0 eration With Ino erable e~ul ment 4.9.B.0 eration W.'th Ino erable ettaui>ment 3.Prom and after'the date"that the.4-kV bus tie board becomes.inoperable,"-reactor operation is permissible indefinitely provided one of the required offsite power sources is not'uppl'ied from-the 161-kV.system through the bus~tie board,.3.When a required: off ite power source is unavailable because the 4-kV bus tie board or-a start bus is INOPERABLE, all unit 3 diesel ge'nerators

~shall.be demonstrated

~ad-dekky thereafter.

The remaining of f sitesource and associated

'uses shall be checked to be energized daily..When one unit 3 4-kV shutdown board is INOPERABLE, continued.reactor operation is permissible for a period of 5 days provided that 2 offsite power sources are available as specified in 3.9.A.l.c and the remaining unit 3 4-kV shutdown'boards and.associated diesel generators, CS.RHR (LPCI and containment cooling)systems, and all unit 3'80-V emergency power boards are OPERABLE.If this requirement cannot be met, an orderly shutdown.shall be initiated and the reactor shall be shut down and in the Cold Condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.4.When one unit 3 4-kV=shutdown board is found to be INOPERABLE, all" generators

~~d the, remaining 4-kV.shutdown boards shall be demonstrated to be thereafter.

\~~>>~)W~~p V-k v)~dr~~~BPN-Unit 3 3.9/4.9-9 r.-~r e.~~C~

V t g~~eŽmpp>E E tmft,A)(yctmEN mrJ'r (gled;",, jQlq".Fujt'Q: Ekn'J jlt'.>JkVE I~:.AN l: HE,>U I REY>EN"."~

3.9.8.0>er at ion Witt>1no><<rgb le etCEuk ment.4.9.B.O~>eratlon With 1no:>eral>le

.E:~ui ment 5.'rom and after the date that one of the 480.-V,diesel-auxiliary board becomes INOPEkABLE, reactor operation i.Wrren one 480-V diesel auxiliary board is fourrd INOPKRABLL.

6.permissible-for a period of 5 days.From and after the date that the 250-V shutdown board 3EB.battery or one of the three 250-V unit batteries and/or its associated.battery board is found to be INOPERABl.E for any reason, continued reactor operat'ion is permissible during the succeeding seven days.Except for routine surveillance testing, the NRC shall be notified, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the situation, the precautions to be taken during this period, and the plans to return the failed component to an OPERABLE state.~~ed-each unit 3 diesel shall be verified OPERABLE~~thereafter.

t p W-4 M~7.-When one division of the logic system is INOPERABLE, continued reactor operation's permissible under this condition for seven-days, provided the CSCS requirements listed in-Specification 3.'9.B.2 are satisfied.

The NRC shall be notified withfh 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the situation, the precautions to be taken during this period, and the plans to return the failed-component to an.OPERABLE state.BFN-Unit 3 3.9/4.9"10 E~.3.9/4.9 AUXILIARY E'RTCAL SY EK LINITIHGCXWDITIOMS POR OPERATION SURVEILLANCE REQUIRBPGKh S 3.9.A Auxil2arv Electr1cal E u2 ent 4.9.h., Auxiliary Electr2cal System 3.9.A.l.c.(Cont'd)4.9.A,.l.(Cont'd).(2), The 500-kV system is.available to the units l.and 2 shutdown boards through the unit" 2 stationmervice transformer TUSS 28 with no credit taken for the two 500-kV Trinity lines.If.the unit 1 station-service transformer is the second choice, a minimum of two 500-kV lines must be available.

(3)The Trinity 161-kV line is a'vailable to.the units 1 and 2 shutdown boards through both common station-service transformers.

NOTES PC@(3): (a)If unit 3 is claiming the Trinity line as an offsite source.see unit 3 technical specifications, section 3.9.A.l.c.2.(b)If unit 1~w.in cold shutciown.

only one common station-se.vice

'ransformer is required.(4)The Athens 16)-kV line is-.available to the units 1 and 2 shutdown boards through a ccxiaaon stationmervice

'ransformer when unit 1 is in Cold Shutdown and unit-3~w not claiming the Athens line as an offsite source-.(2)he diesel starts from ambient condition on the aut~tart signal, energizes the emergency buses with permanently connected loads.energizes the auto-connected emergency loads through load sequencing.

and operates for greater, than or equal to.f"ve minutes while its acne ator m~loaded with the emeraency loads (3)o~rQ cd.bccok~reCAOSeS On On diesel aenerator breaker t ip loads are shed mom the emergency buses and the diesel the auto-s~M.signal, the emergency buses are energized with Once per operating=-cycle.a test will be conducted simulating a loss of offsite power and similar conditions that would exist with the presence of an actual safety-infection signal to demonstrate the following:.

(1)Deenergixation of the emergency, buses and load shedding from the emergency buses.~~I'~2 ar)d 3 3.9/4 9"2 Rr~~1

'I>IF l' ENCLOSURE 2 DESCRIPTION AND JUSTIFICATION BROWNS FERRY NUCLEAR PLANT (BFN)Descri tion of Chan e Technical specifications 4.9.8.1, 2, 3, 4, 5,-and 6 require the remaining diesel generators and associated boards to be tested"immediately and daily-thereafter" whenever a diese'1 generator or other.electrical equipment is.inoperable.

Specifications 4.9.8.3 and 4 also require testing of.the Core Spray (CS)System, the low pressure coolant injection, and the'containment cooling modes of the Residual Heat Removal (RHR)System.This proposed change would require the diesel generators to be demonstrated operable within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and power availability of the associated boards to be verified within one (1)hour and at least once per eight (8)hours thereafter.

The revised specifications would not require any additional testing of the Emergency Core Cooling Systems (ECCS).Technical specification 4.9.A.l.b(3) is changed to correct an editorial error.Reason for Chan e NRC Generic Letter 84-15,"Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability," recommended that the technical specifications be amended to reduce excessive diesel generator starts due to their adverse effect on reliability.

BFN technical specification amendment request 231 dated May 29, 1987 was submitted to implement the recommendations of Generic Letter 84-15.This supplemental response to BFN-TS 231 at the.request of NRC increases the frequency of verification of the associated boards to ensure power availability, reduces excessive testing of the EECS due to its adverse effect on reliability and further reduces required diesel starts.In reviewing the diesel generator section of the technical specifications, an editorial error was found in technical specification 4.9.A.l.b(3) in that the words"restarts on" should be replaced by"output breaker recloses on." Justification for Chan e The safety objective of the Standby A-C Power System is to provide a self-contained, highly reliable source of power so that no single credible.event can disable the core standby cooling functions.

or their supporting auxiliaries.

Eight generators, (four total shared by units 1 and 2, and four for unit 3)are provided as a standby power supply to be used on loss of the normal auxiliary power system.Each of the diesel generators is assigned primarily to one 4.16-kV shutdown board.It is possible, through breaker ties to the shutdown buses, to make connections between units 1, 2, and 3 diesel generators allowing for flexibility in load distribution.

All ac equipment necessary for the safe shutdown of the plant under accident or nonaccident conditions is fed from this distribution system.For the long term (greater than 10 minutes), the Standby Power System is designed so that three of the units 1 and 2 diesel generators, paralleled with three unit 3 diesel generators, are adequate to supply all required loads for the safe shutdown and cooldown of all three units in the event of loss of offsite power and a design basis accident in one unit.

A l>

Justification for Chan e (Cont'd)~~The technical specifications currently contain requirements that have been determined by Generic Letter 84-15 to be-detrimental to the performance of the onsite emergency electrical power system.Therefore, the proposed changes to the technical specification's are to provide'he improvements which are recommended by Generic Letter 84-15 to enhance the.reliability of the diesel generators.

• .The current technical speci:fications require that every diesel be tested."immediately" whenever other power sources are declared inoperable.

This requirement subjects the diesel engine to undue wear and stress'n-the engine parts.To be consi'stent with the philosophy-of reducing excessive testing and thereby enhancing the reliability of the diesel generator, TVA proposes that when the other power sources listed'in the technical specifications are declared inoperable, the remaining diesels, be demonstrated operable within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and'the associated boards verified operable within one hour-and every eight hours thereafter.

A 24-hour interval will reduce unnecessary starting.and stopping of equipment and will'lso=eliminate abusive fast diesel startups and stops that are presently required to test.the diesels immediate.ly..

The associated boards will be verified by verifying correct breaker alignment and indicated power availability.

The increased verification frequency on the associated electr)calboards wi 1 1 provide verification of avail'ability and not adversely effect equipment or significantly consume operator time, since these.survei llances can-be performed from the main control room without actuating.

any mechanical equipment.

These changes are consistent with, the guidance given in Generic Letter 84-15.Deleting the conditional testing of the RHR and CS Systems when an electrical component fails will not reduce'safety since failures.experienced in one train of the electrical system'have no mechanistic connection with performance of operable equipment supplied by other sources of electrical power.Such testing may be detrimental to reliability and avai labi 1:i ty.due to excessive equipment starts, and.test produced failures and unavai labi li ties~..Furthermore, significant operator attention must be devoted to running these tests and realigning the system after the test.The increased surveillance.

of the associated boards wi 11 provide additional assur'ance that power will be.available to this'quipment if needed, without effecting the equipment or power supply.-A related change being corrected as part of this amendment is'an editorial error on technical specification 4.9.A.1(3)'.

Final-Safety Analysis Report section 8.5.5-correctly states that.if an accident occurs during a diesel test the diesel output breaker trips but the diesel remains running and available for service.The technical specification.surveillance requirement incorrectly states that the d.iesel restarts.The proposed changes to BFN units 1, 2, and 3 Technical Specifications are consistent with Generic Letter 84=15.They provide positive improvements to diesel generator reliability..

For these reasons, TVA has concluded that the.proposed changes to the technical specifications will not reduce the margin of plant safety.