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{{#Wiki_filter:NOTES.tBEGULAT(gINFORMATIONDISTBIBUTIONyYSTEM(RIDE>ACCESSIONNBR-7902210226DOC.DATEi79/02/16NOTARIZED~NODOCKET0FACILt50-244RobertEmmetGinnaNuclear.PowerPlant,UnitI,Roches05000244AUTH.NAMEAUTHORAFFILIATIONWHITE,L.D.RochesterGas8,ElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONZIEMANN,.D.L.,OperatingRector+Branch2SUBJECTSForwardsreviewofsafetyactuation..circuitsw/manualoverride.Concludesresetoperationdoesnotpreventequipmentfrom.operating.whi'chisnecessarytonitigateapostulatedaccident.eDISTBIBUTI(>NCODEFAOOISCOPIESRECEIVED(LTRMENCL~SIZE<~TITLE(GENERALDISTRIBUTIONFOBAFTERISSUANCEOFOPERATINGLIC~((-~ll~~a<o45RFCIPIENTIDCODE/NAMEACTION-05BCA@6+~INTERNAL-t03.EGFILE1.215KORE,PERFBR.I7ENGRBR019PLANT.SYSBR21EFLTTRT.SYSEXTERNAL.i03LPDR23ACRSCOPIESLTTRENCL77.II22.I.I,I~1II.I,II1616RECAPIENTID'ODE/NAME02NRCPDRI'((ITA/ED()16AD5YS/PROJ18REACSFTYBR20EEB22BRINKMAN04NSICCOPIESLTTRENCL.III.III.II.II.II.II~((UfgQt6Ad~sgagric~TOTALNUMBER.OFCOPIESREQUIRED'TTR38ENCL38 IE1IIr,rr  
{{#Wiki_filter:NOTES.tBEGULAT(g INFORMATION DISTBIBUTIONyYSTEM (RIDE>ACCESSION NBR-7902210226 DOC.DATEi 79/02/16NOTARIZED~
~Pr~*February16,1979DirectorofNuclearReactorRegulationAttention:Mr.DennisL.Ziemann,ChiefOperatingReactorBranchNo.2U.S.NuclearRegulatoryCommissionWashington,D.C.20555
NODOCKET0FACILt50-244 RobertEmmetGinnaNuclear.PowerPlant,UnitI,Roches05000244AUTH.NAMEAUTHORAFFILIATION WHITE,L.D.
Rochester Gas8,ElectricCorp.RECIP.NAME RECIPIENT AFFILIATION ZIEMANN,.D.L.
,Operating Rector+Branch2SUBJECTSForwardsreviewofsafetyactuation..circuits w/manualoverride.
Concludes resetoperation doesnotpreventequipment from.operating
.whi'chisnecessary tonitigateapostulated accident.
eDISTBIBUTI(>N CODEFAOOISCOPIESRECEIVED(LTR MENCL~SIZE<~TITLE(GENERALDISTRIBUTION FOBAFTERISSUANCEOFOPERATING LIC~((-~ll~~a<o45RFCIPIENTIDCODE/NAME ACTION-05BCA@6+~INTERNAL-t 03.EGFILE1.215KORE,PERF BR.I7ENGRBR019PLANT.SYSBR21EFLTTRT.SYSEXTERNAL.i 03LPDR23ACRSCOPIESLTTRENCL77.II22.I.I,I~1II.I,II1616RECAPIENTID'ODE/NAME 02NRCPDRI'((ITA/ED()16AD5YS/PROJ18REACSFTYBR20EEB22BRINKMAN04NSICCOPIESLTTRENCL.III.III.II.II.II.II~((UfgQt6Ad~sgagric~TOTALNUMBER.OFCOPIESREQUIRED'TTR 38ENCL38 IE1IIr,rr  
~Pr~*February16,1979DirectorofNuclearReactorRegulation Attention:
Mr.DennisL.Ziemann,ChiefOperating ReactorBranchNo.2U.S.NuclearRegulatory Commission Washington, D.C.20555


==Subject:==
==Subject:==
ReviewofSafetyActuationCircuitswithOverridesR.E.GinnaNuclearPowerPlantDocketNo.50-244
ReviewofSafetyActuation CircuitswithOverrides R.E.GinnaNuclearPowerPlantDocketNo.50-244


==DearMr.Ziemann:==
==DearMr.Ziemann:==
4YourletterdatedNovember29,1978requestedrestrictionsbeplacedoncontainmentpurgingduringnormaloperationandthatareviewofallsafetyactuationsignalcircuitswhichincorporatemanualoverridefeaturesbemade.TheRochesterGasandElectricCorporation(RGB)letterdatedJanuary2,1979transmittedtheRG6EcommitmentsonpurgingduringnormaloperationandstatedthattherequiredreviewofoverridefeatureswouldbecompletedbymidFebruary1979.Thepurposeofthisletteristotransmittheresultsofthatreview.DetailsofthereviewarepresentedinAppendixA.Thereviewofallsafetyactuationsignalcircuitswhichincorporateamanualoverridefeatureindicatesthatactuatingaparticularoverride(reset)doesnotcausethebypassofothersafetyactuationsignals.TheresetswitchesdescribedinAppendixAarepushbuttonswitcheslocatedonthecontrolboardwithnophysicalrestraints.Inallcaseswherethesafetyactuationsignalisgeneratedautomaticallyandtheresetswitchisactuated,thesafetyactu-ationsignalwillbeinhibiteduntilalllogicpathsforauto-maticallygeneratingthesafetyactuationsignalhaveopened.Oncealllogicpathsopen,theparticularsafetyactuationsignalresetrelaysde-energizeandre-establishtheabilitytoauto-maticallygeneratethesafetyactuationsignal.Sincetheresetremainsactuatedonlyiftheinputsignalscausingtheautomaticsafetyactuationsignalpersistandtheseinputsignalsareannunciated,noseparateannunciationfortheresetactuationisnecessary.Theoperatorhassufficientinformationtodeducea~certainsystemisintheresetmode.p0v80zzaoww4e,'g~(g',
4YourletterdatedNovember29,1978requested restrictions beplacedoncontainment purgingduringnormaloperation andthatareviewofallsafetyactuation signalcircuitswhichincorporate manualoverridefeaturesbemade.TheRochester GasandElectricCorporation (RGB)letterdatedJanuary2,1979transmitted theRG6Ecommitments onpurgingduringnormaloperation andstatedthattherequiredreviewofoverridefeatureswouldbecompleted bymidFebruary1979.Thepurposeofthisletteristotransmittheresultsofthatreview.Detailsofthereviewarepresented inAppendixA.Thereviewofallsafetyactuation signalcircuitswhichincorporate amanualoverridefeatureindicates thatactuating aparticular override(reset)doesnotcausethebypassofothersafetyactuation signals.Theresetswitchesdescribed inAppendixAarepushbuttonswitcheslocatedonthecontrolboardwithnophysicalrestraints.
ROCHFST=RGwSAiVOL=CTR)CCORP.February16,1979TcMr.D.L.Ziemann,ChiefryEET,VO1Znnocasedoesactuationofaparticularresetswitchpreventtheoperatorfrommanuallyoperatingtheequipmentfromthecontrolboard.Therefore,operationofaresetdoesnotpreventequipmentfromoperatingwhichisnecessarytomitigatetheconsequencesofapostulatedaccident.Verytrulyyours,~~+L.D.White,Jr.LDW:npAttachment AppendixAReviewofSafetyActuationSignalCircuitsIncorporatingmanualOverridesThefollowingsummaxizestheresultsofareviewofsafetyactu-ationsignalcircuitswhichincorporateamanualoverridefeature.Thepurposeofthereviewistoensurethatoverridingofonesafetyactuationsignaldoesnotalsocausethebypassofanyothersafetyactuationsignals:SAFETYINJECTIONCIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresettingsafetyinjectionone-minuteorlongerafterinitiation.Actuationofthereset.swatchinitselfdoesnotchangethestateofanyequipment,butpermitstheoperatortoplacetheequipmentaffectedbysafetyinjectiontothepositiondesired.Ifsafetyin]ectioniscausedbyautomaticactuation,andtheresetswitchisactuated,automaticsafetyingectionwillbeinhibiteduntilalllogicpathsforautomaticsafetyinjectionhaveopened.Oncealllogicpathsopen,thesafetyinjectionresetrelaysde-energizeandre-establishesautomaticsafetyinjectioncapabilities.Manualsafetyinjectioninitiationisavailableatalltimes.Thereisnoannunciationofthesafetyxngectioncircuitbeingintheresetmode.ThepurposeoftheresetswitchonthesafetyinjectionsystemistoallowequipmenttoberealignedfortherecirculationphaseofapostulatedLOCA.2.CONTAINMENTVENTILATIONISOLATIONCIRCUIT:Thiscircuithasaresetswitchwhichgivestheopexatorthemeansofresettingcontainmentventilationisolation.Oncetheresetswitchhasbeenactuated,most'oftneequipment.willautomaticallyreturntothestateselectedpriortotheisolationsignal.Ifcontainmentventilationisolationwascausedautomatically,eitherbysafetyinjectionorhighradiationalarmoncontainmentgasand/orparticulatemonitors,andthisconditioncontinuestoexist:afterthexesetswitchhasbeenactuated,thencontainmentventilationisolationcannotbeachievedautomaticallyorbythemanualisolationswitchesuntilth'islogicclears.Oncetheautomaticlogicclears,thecontainmentventilationisolationresetrelaysde-energizeandre-establishesautomaticormanualisolationcapabilities.
Inallcaseswherethesafetyactuation signalisgenerated automatically andtheresetswitchisactuated, thesafetyactu-ationsignalwillbeinhibited untilalllogicpathsforauto-matically generating thesafetyactuation signalhaveopened.Oncealllogicpathsopen,theparticular safetyactuation signalresetrelaysde-energize andre-establish theabilitytoauto-matically generatethesafetyactuation signal.Sincetheresetremainsactuatedonlyiftheinputsignalscausingtheautomatic safetyactuation signalpersistandtheseinputsignalsareannunciated, noseparateannunciation fortheresetactuation isnecessary.
Manualoperationofthevalvesfromthecontrolboardisavailableatalltimes.Thereisnoannunciationoftheautomaticcontainmentventilationisolationsystembeingintheresetmode.IJThepurposeoftheresetswitchonthecontainmentventi-lationisolationsystemistoallowpurgingofcontainmentinordertolimitpotentialhydrogenconcentrationbuildupfollowingapostulatedLOCAwhenhighcontainmentactivityandsafetyinjectionsignalscouldbepresent.3.CONTAINMENTISOLATIONCIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresettingcontainment.isolation.Oncetheresetswitchhasbeenactuated,someequipmentwillreturn,automaticallytothepositionselectedpriortotheiso-lationsignal.Ifcontainmentisolationwascausedautomaticallybyanautomaticsafetyinjectionsignal,andcontainmentiso-lationresetswitchisactuatedwithoutresettingsafetyinjection,containmentisolationcannotbeobtainedbythemanualcontainmentisolationswitchesuntilsafetyinjec-tionisreset.Actuationoftheresetpermitstheoperatortoplacethevalvesaffectedbythecontainmentisolationsignalintheposition~desired.Thiscapabilityisnecessarysothattheoperatorhasflexibilityindealingwithpostaccidentconditionswithincontainment.Thereisnoannunciat'ionoftheautomaticcontainmentisolationbeingintheresetmode.4.CONTAINMENTSPRAYCIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresettingcontainmentspray.Oncetheresetswitchhasbeenactuatedthesprayadditivetankdischargevalveswillreturnautomaticallytothepositioncalledforbythecontrollerpriortothecontainmentspraysignal.Thecontainmentspraypumpsandtheirdischargevalveswouldrequireoperatoractiontochangestate.Ifcontainmentspraywascausedautomaticallybythehighcontainmentpressurelogic,andthislogiccontinuestoexistafterreset,containmentspraycannotbeinitiatedbythemanualsprayswitches.Oncethehighpressurelogichascleared,thecontainmentsprayresetrelaysde-energizeandre-establishesautomaticormanualcontain-mentspraycapabilities.
Theoperatorhassufficient information todeducea~certainsystemisintheresetmode.p0v80zzaoww4 e,'g~(g',
Actuationoftheresetpermitstheoperatortoplacethevalvesandpumpsaffectedbythecontainmentspraysignalinthestatedesired.Thiscapabilityisnecessarysothattheoperatorhasflexibilityindealingwithpostaccidentconditionswithincontainment.Thereisnoannunciationoftheautomaticcontainmentspraysystembeingintheresetmode.5.FEEDNATERISOLATIONRESET:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresettingtheisolationsignaltothefeed-waterbypassvalvesonly.Themainfeedwatervalveswillremaincloseduntiltheisolationlogicclears,andthentheyautomaticallyassumethepositionrequestedbytheircontrolcircuit.Iffeedwaterisolationiscausedbyhighsteamgeneratorlevellogic,andthisconditionstillexistsaftertheresetswitchisactuated,-asafetyinjectionsign'alwouldnotcauseanisolationtothatparticularfeedwaterbypassvalve.Itshouldbenotedthatasafetyinjectionsignalalsocausesthemainfeedwaterpumpstobetripped,therefore,closingthefeedwaterbypassvalvesonasafetyinjectionsignalisredundant.Thereisnoannunciationoftheautomaticfeedwateriso-lationsystembeingintheresetmode.6NUCLEARINSTRUMENTATIONSYSTEMDEFEAT~BYPASSgANDBLOCKSWITCHES:~Thissystemhasseveralswitcheswhichareusedforthefollowingpurposes:(a)DefeatSwitches-Defeatsapermissivewhichrein-statesatriplogic.(b)BypassSwitches-Bypassesatriporrunbackfunctionforcalibrationormaintenancepurposes.Protectionisstillprovidedbyredundantchannelorchannels.(c)BlockSwitches-Blockstripsgeneratedbysource,.intermediate,andpowerrangechannels.Theseswitchesareactuatedaspermissivesetpointsarereachedtopermittakingreactorcriticalandupinpower.Theseblocksautomaticallyresetaspowerisdecreasedbelowitsparticularsetpoint.Alltheaboveswitchesifactuated,areindicatedbyoneormoreofthefollowing:statuslight,alarmonthecomputer,oractuateanannunciator.
ROCHFST=R GwSAiVOL=CTR)CCORP.February16,1979TcMr.D.L.Ziemann,ChiefryEET,VO1Znnocasedoesactuation ofaparticular resetswitchpreventtheoperatorfrommanuallyoperating theequipment fromthecontrolboard.Therefore, operation ofaresetdoesnotpreventequipment fromoperating whichisnecessary tomitigatetheconsequences ofapostulated accident.
7.INSTRUMENTANDCONTROLDEFEATSWITCHES:Thefollowingswitchesandtheircircuitswerereviewedtoinsurethattheyareonlyperformingtheirintendedfunction,andnoothersafetyfunctionsarebeingbypassed.The-purposefortheseswitchesistobeabletoswitchcontrolfromonesensorlooptoanotherfortesting,calibrationandmaintenancepurposes.Inallcases,reactortripandsafetyinjectionsignalsaregeneratedpriortodefeatswitches,andarenotaffectedbyswitchposition.(a)P/429APressurizerPressureSelectorSwitcn-Usedtoselecttwoofthefourpressurizerpressurechannelsforcontrollingpressurizerheaters,sprays,andpowerreliefvalvePCV-430.(b)L/428APressurizerLevelSelectorSwitch-Vsedtosele'cttwoofthethreepressurizerlevelchannelsforcontrollingchargingpumpspeed,letdowniso-lation,andpressurizerheaters.(c)T/405EandT/405FDeltaTDefeatSwitches-Vsedtodefeatachannelfromtheovertemperatureandoverpowerturbinerunbackcircuit,andtoremoveachannelDeltaTsignalfromtheinputofthesummerforgeneratingtheaverageDeltaTsignalortheRodInsertionLimitCircuit.(d)T/401AandT/401BTavgDefeatSwitches-UsedtodefeataTavgchannelfromtheinputtotheaverageTavgsummerwhichisusedforfulllengthrodcontrol,condensersteamdump,andpressurizerlevelsetpoint.}}
Verytrulyyours,~~+L.D.White,Jr.LDW:npAttachment AppendixAReviewofSafetyActuation SignalCircuitsIncorporating manualOverrides Thefollowing summaxizes theresultsofareviewofsafetyactu-ationsignalcircuitswhichincorporate amanualoverridefeature.Thepurposeofthereviewistoensurethatoverriding ofonesafetyactuation signaldoesnotalsocausethebypassofanyothersafetyactuation signals:SAFETYINJECTION CIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting safetyinjection one-minuteorlongerafterinitiation.
Actuation ofthereset.swatchinitselfdoesnotchangethestateofanyequipment, butpermitstheoperatortoplacetheequipment affectedbysafetyinjection tothepositiondesired.Ifsafetyin]ection iscausedbyautomatic actuation, andtheresetswitchisactuated, automatic safetyingection willbeinhibited untilalllogicpathsforautomatic safetyinjection haveopened.Oncealllogicpathsopen,thesafetyinjection resetrelaysde-energize andre-establishes automatic safetyinjection capabilities.
Manualsafetyinjection initiation isavailable atalltimes.Thereisnoannunciation ofthesafetyxngection circuitbeingintheresetmode.Thepurposeoftheresetswitchonthesafetyinjection systemistoallowequipment toberealigned fortherecirculation phaseofapostulated LOCA.2.CONTAINMENT VENTILATION ISOLATION CIRCUIT:Thiscircuithasaresetswitchwhichgivestheopexatorthemeansofresetting containment ventilation isolation.
Oncetheresetswitchhasbeenactuated, most'oftneequipment.
willautomatically returntothestateselectedpriortotheisolation signal.Ifcontainment ventilation isolation wascausedautomatically, eitherbysafetyinjection orhighradiation alarmoncontainment gasand/orparticulate
: monitors, andthiscondition continues toexist:afterthexesetswitchhasbeenactuated, thencontainment ventilation isolation cannotbeachievedautomatically orbythemanualisolation switchesuntilth'islogicclears.Oncetheautomatic logicclears,thecontainment ventilation isolation resetrelaysde-energize andre-establishes automatic ormanualisolation capabilities.
Manualoperation ofthevalvesfromthecontrolboardisavailable atalltimes.Thereisnoannunciation oftheautomatic containment ventilation isolation systembeingintheresetmode.IJThepurposeoftheresetswitchonthecontainment venti-lationisolation systemistoallowpurgingofcontainment inordertolimitpotential hydrogenconcentration buildupfollowing apostulated LOCAwhenhighcontainment activityandsafetyinjection signalscouldbepresent.3.CONTAINMENT ISOLATION CIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting containment
.isolation.
Oncetheresetswitchhasbeenactuated, someequipment willreturn,automatically tothepositionselectedpriortotheiso-lationsignal.Ifcontainment isolation wascausedautomatically byanautomatic safetyinjection signal,andcontainment iso-lationresetswitchisactuatedwithoutresetting safetyinjection, containment isolation cannotbeobtainedbythemanualcontainment isolation switchesuntilsafetyinjec-tionisreset.Actuation oftheresetpermitstheoperatortoplacethevalvesaffectedbythecontainment isolation signalintheposition~desired.
Thiscapability isnecessary sothattheoperatorhasflexibility indealingwithpostaccidentconditions withincontainment.
Thereisnoannunciat'ion oftheautomatic containment isolation beingintheresetmode.4.CONTAINMENT SPRAYCIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting containment spray.Oncetheresetswitchhasbeenactuatedthesprayadditivetankdischarge valveswillreturnautomatically tothepositioncalledforbythecontroller priortothecontainment spraysignal.Thecontainment spraypumpsandtheirdischarge valveswouldrequireoperatoractiontochangestate.Ifcontainment spraywascausedautomatically bythehighcontainment pressurelogic,andthislogiccontinues toexistafterreset,containment spraycannotbeinitiated bythemanualsprayswitches.
Oncethehighpressurelogichascleared,thecontainment sprayresetrelaysde-energize andre-establishes automatic ormanualcontain-mentspraycapabilities.
Actuation oftheresetpermitstheoperatortoplacethevalvesandpumpsaffectedbythecontainment spraysignalinthestatedesired.Thiscapability isnecessary sothattheoperatorhasflexibility indealingwithpostaccidentconditions withincontainment.
Thereisnoannunciation oftheautomatic containment spraysystembeingintheresetmode.5.FEEDNATER ISOLATION RESET:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting theisolation signaltothefeed-waterbypassvalvesonly.Themainfeedwater valveswillremaincloseduntiltheisolation logicclears,andthentheyautomatically assumethepositionrequested bytheircontrolcircuit.Iffeedwater isolation iscausedbyhighsteamgenerator levellogic,andthiscondition stillexistsaftertheresetswitchisactuated,-a safetyinjection sign'alwouldnotcauseanisolation tothatparticular feedwater bypassvalve.Itshouldbenotedthatasafetyinjection signalalsocausesthemainfeedwater pumpstobetripped,therefore, closingthefeedwater bypassvalvesonasafetyinjection signalisredundant.
Thereisnoannunciation oftheautomatic feedwater iso-lationsystembeingintheresetmode.6NUCLEARINSTRUMENTATION SYSTEMDEFEAT~BYPASSgANDBLOCKSWITCHES:
~Thissystemhasseveralswitcheswhichareusedforthefollowing purposes:
(a)DefeatSwitches-Defeatsapermissive whichrein-statesatriplogic.(b)BypassSwitches-Bypassesatriporrunbackfunctionforcalibration ormaintenance purposes.
Protection isstillprovidedbyredundant channelorchannels.
(c)BlockSwitches-Blockstripsgenerated bysource,.intermediate, andpowerrangechannels.
Theseswitchesareactuatedaspermissive setpoints arereachedtopermittakingreactorcriticalandupinpower.Theseblocksautomatically resetaspowerisdecreased belowitsparticular setpoint.
Alltheaboveswitchesifactuated, areindicated byoneormoreofthefollowing:
statuslight,alarmonthecomputer, oractuateanannunciator.
7.INSTRUMENT ANDCONTROLDEFEATSWITCHES:
Thefollowing switchesandtheircircuitswerereviewedtoinsurethattheyareonlyperforming theirintendedfunction, andnoothersafetyfunctions arebeingbypassed.
The-purposefortheseswitchesistobeabletoswitchcontrolfromonesensorlooptoanotherfortesting,calibration andmaintenance purposes.
Inallcases,reactortripandsafetyinjection signalsaregenerated priortodefeatswitches, andarenotaffectedbyswitchposition.
(a)P/429APressurizer PressureSelectorSwitcn-Usedtoselecttwoofthefourpressurizer pressurechannelsforcontrolling pressurizer heaters,sprays,andpowerreliefvalvePCV-430.(b)L/428APressurizer LevelSelectorSwitch-Vsedtosele'cttwoofthethreepressurizer levelchannelsforcontrolling chargingpumpspeed,letdowniso-lation,andpressurizer heaters.(c)T/405EandT/405FDeltaTDefeatSwitches-Vsedtodefeatachannelfromtheovertemperature andoverpowerturbinerunbackcircuit,andtoremoveachannelDeltaTsignalfromtheinputofthesummerforgenerating theaverageDeltaTsignalortheRodInsertion LimitCircuit.(d)T/401AandT/401BTavgDefeatSwitches-UsedtodefeataTavgchannelfromtheinputtotheaverageTavgsummerwhichisusedforfulllengthrodcontrol,condenser steamdump,andpressurizer levelsetpoint.}}

Revision as of 15:04, 29 June 2018

Forwards Review of Safety Actuation Circuits W/Manual Override.Reset Operation Does Not Prevent Equipment from Operating,Which Is Necessary to Mitigate a Postulated Accident
ML17244A374
Person / Time
Site: Ginna Constellation icon.png
Issue date: 02/16/1979
From: WHITE L D
ROCHESTER GAS & ELECTRIC CORP.
To: ZIEMANN D L
Office of Nuclear Reactor Regulation
References
TASK-06-04, TASK-6-4, TASK-RR NUDOCS 7902210226
Download: ML17244A374 (8)


Text

NOTES.tBEGULAT(g INFORMATION DISTBIBUTIONyYSTEM (RIDE>ACCESSION NBR-7902210226 DOC.DATEi 79/02/16NOTARIZED~

NODOCKET0FACILt50-244 RobertEmmetGinnaNuclear.PowerPlant,UnitI,Roches05000244AUTH.NAMEAUTHORAFFILIATION WHITE,L.D.

Rochester Gas8,ElectricCorp.RECIP.NAME RECIPIENT AFFILIATION ZIEMANN,.D.L.

,Operating Rector+Branch2SUBJECTSForwardsreviewofsafetyactuation..circuits w/manualoverride.

Concludes resetoperation doesnotpreventequipment from.operating

.whi'chisnecessary tonitigateapostulated accident.

eDISTBIBUTI(>N CODEFAOOISCOPIESRECEIVED(LTR MENCL~SIZE<~TITLE(GENERALDISTRIBUTION FOBAFTERISSUANCEOFOPERATING LIC~((-~ll~~a<o45RFCIPIENTIDCODE/NAME ACTION-05BCA@6+~INTERNAL-t 03.EGFILE1.215KORE,PERF BR.I7ENGRBR019PLANT.SYSBR21EFLTTRT.SYSEXTERNAL.i 03LPDR23ACRSCOPIESLTTRENCL77.II22.I.I,I~1II.I,II1616RECAPIENTID'ODE/NAME 02NRCPDRI'((ITA/ED()16AD5YS/PROJ18REACSFTYBR20EEB22BRINKMAN04NSICCOPIESLTTRENCL.III.III.II.II.II.II~((UfgQt6Ad~sgagric~TOTALNUMBER.OFCOPIESREQUIRED'TTR 38ENCL38 IE1IIr,rr

~Pr~*February16,1979DirectorofNuclearReactorRegulation Attention:

Mr.DennisL.Ziemann,ChiefOperating ReactorBranchNo.2U.S.NuclearRegulatory Commission Washington, D.C.20555

Subject:

ReviewofSafetyActuation CircuitswithOverrides R.E.GinnaNuclearPowerPlantDocketNo.50-244

DearMr.Ziemann:

4YourletterdatedNovember29,1978requested restrictions beplacedoncontainment purgingduringnormaloperation andthatareviewofallsafetyactuation signalcircuitswhichincorporate manualoverridefeaturesbemade.TheRochester GasandElectricCorporation (RGB)letterdatedJanuary2,1979transmitted theRG6Ecommitments onpurgingduringnormaloperation andstatedthattherequiredreviewofoverridefeatureswouldbecompleted bymidFebruary1979.Thepurposeofthisletteristotransmittheresultsofthatreview.Detailsofthereviewarepresented inAppendixA.Thereviewofallsafetyactuation signalcircuitswhichincorporate amanualoverridefeatureindicates thatactuating aparticular override(reset)doesnotcausethebypassofothersafetyactuation signals.Theresetswitchesdescribed inAppendixAarepushbuttonswitcheslocatedonthecontrolboardwithnophysicalrestraints.

Inallcaseswherethesafetyactuation signalisgenerated automatically andtheresetswitchisactuated, thesafetyactu-ationsignalwillbeinhibited untilalllogicpathsforauto-matically generating thesafetyactuation signalhaveopened.Oncealllogicpathsopen,theparticular safetyactuation signalresetrelaysde-energize andre-establish theabilitytoauto-matically generatethesafetyactuation signal.Sincetheresetremainsactuatedonlyiftheinputsignalscausingtheautomatic safetyactuation signalpersistandtheseinputsignalsareannunciated, noseparateannunciation fortheresetactuation isnecessary.

Theoperatorhassufficient information todeducea~certainsystemisintheresetmode.p0v80zzaoww4 e,'g~(g',

ROCHFST=R GwSAiVOL=CTR)CCORP.February16,1979TcMr.D.L.Ziemann,ChiefryEET,VO1Znnocasedoesactuation ofaparticular resetswitchpreventtheoperatorfrommanuallyoperating theequipment fromthecontrolboard.Therefore, operation ofaresetdoesnotpreventequipment fromoperating whichisnecessary tomitigatetheconsequences ofapostulated accident.

Verytrulyyours,~~+L.D.White,Jr.LDW:npAttachment AppendixAReviewofSafetyActuation SignalCircuitsIncorporating manualOverrides Thefollowing summaxizes theresultsofareviewofsafetyactu-ationsignalcircuitswhichincorporate amanualoverridefeature.Thepurposeofthereviewistoensurethatoverriding ofonesafetyactuation signaldoesnotalsocausethebypassofanyothersafetyactuation signals:SAFETYINJECTION CIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting safetyinjection one-minuteorlongerafterinitiation.

Actuation ofthereset.swatchinitselfdoesnotchangethestateofanyequipment, butpermitstheoperatortoplacetheequipment affectedbysafetyinjection tothepositiondesired.Ifsafetyin]ection iscausedbyautomatic actuation, andtheresetswitchisactuated, automatic safetyingection willbeinhibited untilalllogicpathsforautomatic safetyinjection haveopened.Oncealllogicpathsopen,thesafetyinjection resetrelaysde-energize andre-establishes automatic safetyinjection capabilities.

Manualsafetyinjection initiation isavailable atalltimes.Thereisnoannunciation ofthesafetyxngection circuitbeingintheresetmode.Thepurposeoftheresetswitchonthesafetyinjection systemistoallowequipment toberealigned fortherecirculation phaseofapostulated LOCA.2.CONTAINMENT VENTILATION ISOLATION CIRCUIT:Thiscircuithasaresetswitchwhichgivestheopexatorthemeansofresetting containment ventilation isolation.

Oncetheresetswitchhasbeenactuated, most'oftneequipment.

willautomatically returntothestateselectedpriortotheisolation signal.Ifcontainment ventilation isolation wascausedautomatically, eitherbysafetyinjection orhighradiation alarmoncontainment gasand/orparticulate

monitors, andthiscondition continues toexist:afterthexesetswitchhasbeenactuated, thencontainment ventilation isolation cannotbeachievedautomatically orbythemanualisolation switchesuntilth'islogicclears.Oncetheautomatic logicclears,thecontainment ventilation isolation resetrelaysde-energize andre-establishes automatic ormanualisolation capabilities.

Manualoperation ofthevalvesfromthecontrolboardisavailable atalltimes.Thereisnoannunciation oftheautomatic containment ventilation isolation systembeingintheresetmode.IJThepurposeoftheresetswitchonthecontainment venti-lationisolation systemistoallowpurgingofcontainment inordertolimitpotential hydrogenconcentration buildupfollowing apostulated LOCAwhenhighcontainment activityandsafetyinjection signalscouldbepresent.3.CONTAINMENT ISOLATION CIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting containment

.isolation.

Oncetheresetswitchhasbeenactuated, someequipment willreturn,automatically tothepositionselectedpriortotheiso-lationsignal.Ifcontainment isolation wascausedautomatically byanautomatic safetyinjection signal,andcontainment iso-lationresetswitchisactuatedwithoutresetting safetyinjection, containment isolation cannotbeobtainedbythemanualcontainment isolation switchesuntilsafetyinjec-tionisreset.Actuation oftheresetpermitstheoperatortoplacethevalvesaffectedbythecontainment isolation signalintheposition~desired.

Thiscapability isnecessary sothattheoperatorhasflexibility indealingwithpostaccidentconditions withincontainment.

Thereisnoannunciat'ion oftheautomatic containment isolation beingintheresetmode.4.CONTAINMENT SPRAYCIRCUIT:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting containment spray.Oncetheresetswitchhasbeenactuatedthesprayadditivetankdischarge valveswillreturnautomatically tothepositioncalledforbythecontroller priortothecontainment spraysignal.Thecontainment spraypumpsandtheirdischarge valveswouldrequireoperatoractiontochangestate.Ifcontainment spraywascausedautomatically bythehighcontainment pressurelogic,andthislogiccontinues toexistafterreset,containment spraycannotbeinitiated bythemanualsprayswitches.

Oncethehighpressurelogichascleared,thecontainment sprayresetrelaysde-energize andre-establishes automatic ormanualcontain-mentspraycapabilities.

Actuation oftheresetpermitstheoperatortoplacethevalvesandpumpsaffectedbythecontainment spraysignalinthestatedesired.Thiscapability isnecessary sothattheoperatorhasflexibility indealingwithpostaccidentconditions withincontainment.

Thereisnoannunciation oftheautomatic containment spraysystembeingintheresetmode.5.FEEDNATER ISOLATION RESET:Thiscircuithasaresetswitchwhichgivestheoperatorthemeansofresetting theisolation signaltothefeed-waterbypassvalvesonly.Themainfeedwater valveswillremaincloseduntiltheisolation logicclears,andthentheyautomatically assumethepositionrequested bytheircontrolcircuit.Iffeedwater isolation iscausedbyhighsteamgenerator levellogic,andthiscondition stillexistsaftertheresetswitchisactuated,-a safetyinjection sign'alwouldnotcauseanisolation tothatparticular feedwater bypassvalve.Itshouldbenotedthatasafetyinjection signalalsocausesthemainfeedwater pumpstobetripped,therefore, closingthefeedwater bypassvalvesonasafetyinjection signalisredundant.

Thereisnoannunciation oftheautomatic feedwater iso-lationsystembeingintheresetmode.6NUCLEARINSTRUMENTATION SYSTEMDEFEAT~BYPASSgANDBLOCKSWITCHES:

~Thissystemhasseveralswitcheswhichareusedforthefollowing purposes:

(a)DefeatSwitches-Defeatsapermissive whichrein-statesatriplogic.(b)BypassSwitches-Bypassesatriporrunbackfunctionforcalibration ormaintenance purposes.

Protection isstillprovidedbyredundant channelorchannels.

(c)BlockSwitches-Blockstripsgenerated bysource,.intermediate, andpowerrangechannels.

Theseswitchesareactuatedaspermissive setpoints arereachedtopermittakingreactorcriticalandupinpower.Theseblocksautomatically resetaspowerisdecreased belowitsparticular setpoint.

Alltheaboveswitchesifactuated, areindicated byoneormoreofthefollowing:

statuslight,alarmonthecomputer, oractuateanannunciator.

7.INSTRUMENT ANDCONTROLDEFEATSWITCHES:

Thefollowing switchesandtheircircuitswerereviewedtoinsurethattheyareonlyperforming theirintendedfunction, andnoothersafetyfunctions arebeingbypassed.

The-purposefortheseswitchesistobeabletoswitchcontrolfromonesensorlooptoanotherfortesting,calibration andmaintenance purposes.

Inallcases,reactortripandsafetyinjection signalsaregenerated priortodefeatswitches, andarenotaffectedbyswitchposition.

(a)P/429APressurizer PressureSelectorSwitcn-Usedtoselecttwoofthefourpressurizer pressurechannelsforcontrolling pressurizer heaters,sprays,andpowerreliefvalvePCV-430.(b)L/428APressurizer LevelSelectorSwitch-Vsedtosele'cttwoofthethreepressurizer levelchannelsforcontrolling chargingpumpspeed,letdowniso-lation,andpressurizer heaters.(c)T/405EandT/405FDeltaTDefeatSwitches-Vsedtodefeatachannelfromtheovertemperature andoverpowerturbinerunbackcircuit,andtoremoveachannelDeltaTsignalfromtheinputofthesummerforgenerating theaverageDeltaTsignalortheRodInsertion LimitCircuit.(d)T/401AandT/401BTavgDefeatSwitches-UsedtodefeataTavgchannelfromtheinputtotheaverageTavgsummerwhichisusedforfulllengthrodcontrol,condenser steamdump,andpressurizer levelsetpoint.