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Revision 22USAR 8.1MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 1SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.1SummaryThe plant electrical power system is designed to provide a diversity of dependablepower sources which are physically isolated so that any one failure affecting one source of supply will not propagate to alternate sources. The plant auxiliaryelectrical power systems are designed to provide electrical and physicalindependence and adequate power supplies for startup, operation, shutdown, and for other plant requirements which are important to safety.In the event of a loss or degradation of all off-site power sources, auxiliary powerwill be supplied from diesel generators located on the site. These power sources are physically independent from any normal power system. Each power source, up to the point of its connection to the auxiliary power bus, is capable of completeand rapid electrical isolation from any other sources. Loads important to plantsafety are split and diversified between switchgear sections and means are provided for rapid location and isolation of system faults. Plant batteries are provided as a reliable source of control power for specific engineered safeguards and other functions required when AC power is not available.FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.01Doc Type:Admin Initials:Date:9703 Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of2SECTION8PLANTELECTRICALSYSTEMSI/eak8.2TransmissionSystem8.2.1NetworkInterconnectionsOutputoftheMonticelloNuclearGeneratingPlantisdeliveredtoa345/230/115/13.8KVswitchyardlocatedontheplantsite.DrawingNH-178635, Section15,showstheonelinediagramfortheMonticelloplantandits connectionstothetransmissionsystem.The345KVportionoftheswitchyardhaspositionsforconnectingthegeneratoroutput,threetransmissionlines,a345-230-13.8KVautotransformera345-13.8KVtransformer,a345-34.5KVtransformer,anda345-115-13.8KV autotransformer.The345KVbusandcircuitbreakerarrangementisa breaker-and-one-halfsystem.One345KVtransmissionlineisroutedtoconnect intothe345KVlooparoundtheTwinCitiesMetropolitanAreaattheElmCreekSubstation.Thesecondlineconnectstothe345KVtransmissionsystematSherburneCountySubstation.Thethirdlineconnectstothe345KVQuarry Substation.The230KVportionoftheswitchyardisprovidedtoestablishaninterconnectionwiththetransmissionsystemoftheGreatRiverEnergy.Anautotransformerconnectsthe345KVand230KVbusses.The115KVportionoftheswitchyardisconnectedtothe345KVbusthroughanautotransformer.The115KVbusisarrangedinaringbusconfiguration.In additiontotheautotransformerconnectiontothe115KVbus,therearethree transmissionlineconnectionsandaconnectiontoaplantauxiliarytransformer.Oneofthethreetransmissionlinesconnectsintothe115KVtransmission systematLakePulaskiSubstationandatDickinsonSubstation,anotheratHassanSubstation,andthethird115KVlineconnectstotheLibertysubstation.The13.8KVportionoftheswitchyardisprovidedtoestablishreliablepowersourcestovariousplantequipment.Theseincludetheplantauxiliaryreservetransformer(1AR);dischargestructuretransformers(X7,X8);coolingtowerfan transformers(X50,X60,X70,X80);transformerXP91whichpowersthe hydrogenwaterchemistrycryogenicsystempanelandanalternatefeed (throughtransformer6)tothetrainingcenter. | |||
Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of2I/eakThesix(345KVand115KV)transmissionlineconnectionstotheswitchyardareallconnectedintotheXcelEnergyinterconnectedtransmissiongrid.Theirpointsofconnectiontothegridarearrangedbyroutesandintra-right-of-wayspacingtominimizemultiplelineoutageswhileperformingtherequirementof deliveringpowertolocationswhichbestsatisfysystemgrowthneeds.The345KVand115KVlines,aswellasthelinestowhichtheyinterconnect,are designedandbuilttoexceedtherequirementsoftheNationalElectricSafetyCodeforheavyloadingdistricts,GradeBconstruction(Reference41).Lightningperformancedesignofthetransmissionlinesisbasedonlessthanoneoutage per100milesperyear.ThesixXcelEnergytransmissionlinesleavetheMonticellosubstationthroughfourseparaterights-of-way:SherburneCountylinecorridor;Libertylinecorridor; Quarrycorridor;andacommoncorridorfortheElmCreek,Dickinson-LakePulaski,andHassanlines.Theserights-of-wayareconsideredindependentastheyaregreaterthan1/4mileapartatadistanceof1milefromtheplant.Threetransformersareprovidedtosupplytheplantwithoffsitepowerfromthesubstation.Allthreesourcescanindependentlyprovideadequatepowerforthe plant'ssafety-relatedloads.Thesetransformersandtheirinterconnectionsto thesubstationareasfollows:Theprimarystationauxiliarytransformer,2R,isfedfrom345KVBusNo.1via345KVto34.5KVtransformer2RS,andundergroundcablingfromthesubstationtotheareanorthwestoftheturbinebuildingwhere2Rtransformer islocated.2Rtransformerisofadequatesizetoprovidetheplant'sfull auxiliaryloadrequirements.Thereservetransformer,1R,isfedfromthe115KVsubstationviaanoverheadlinefromthesubstationtotheareanorthwestoftheturbinebuildingwhere1Rtransformerislocated.1Rtransformerisofadequatesizetoprovidetheplant'sfullauxiliaryloadrequirements.Thereserveauxiliarytransformer,1AR,islocatedsouthwestofthereactorbuildingandmaybefedfromtwoseparate13.8KVsourcesinthe substation.Onemethodofsupplying1ARtransformerisfromthetertiary windingof#10transformer,theauto-transformerwhichinterconnectsthe345KVand115KVsystems.Powerisroutedfromthetertiarywindingof10transformerto1ARviacircuitbreaker1N2andundergroundcablingfromthe substationto1ARtransformer.Thealternatemethodoffeeding1ARisfrom the345KVsubstationvia345KVto13.8KVtransformer1ARS,circuit breaker1N6,andundergroundcablingfromthesubstationto1AR.Circuitbreakers1N2and1N6areinterlockedtopreventhavingbothbreakerssimultaneouslyintheclosedposition.1ARtransformerissizedtoprovide onlytheplant'sessential4160Vacbusesandconnectedloads.01405303 SECTION 88.38.3.1 | |||
8.3.2 | |||
8.3.3 | |||
8.3.4 | |||
8.3.5 | |||
bus tie breaker for Load Centers 101 and 102 is physically located in LC-102 | |||
SECTION 88.48.4.1 | |||
8.4.2 | |||
NOTE 1:NOTE 2:NOTE 3:NOTE 4:NOTE 5:NOTE 6:NOTE 7:NOTE 8: | |||
NOTE 9:NOTE 10: | |||
NOTE 11:NOTE 12:NOTE 13:NOTE 14: | |||
SECTION 88.5 | |||
8.5.1 | |||
8.5.2 | |||
8.5.3 | |||
8.5.4 | |||
8.5.5 | |||
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 3SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.6Reactor Protection System Power Supplies8.6.1Design BasisTwo motor generator sets provide AC power for operation of the ReactorProtection System. These sets are powered from 480 Vac buses and are used to supply power to the scram logic channels as well as neutron and radiationmonitoring systems. These sets are termed interruptible power supplies sinceloss of AC power to them causes a delayed loss of output as the inertial energy of the flywheel is converted to power for the connected loads.These systems are designed to provide a continued output of 120 Vac powerthat is free of transients and is extremely reliable. Switching transients andmomentary losses of input power will not cause substantial changes in outputvoltage or frequency.8.6.2DescriptionInterruptible Power SuppliesThe normal power supply will consist of two motor generator sets, eachconsisting of a three-phase induction motor driving a 120 Vac single-phasegenerator with flywheel. The flywheel provides energy to maintain generator output during momentary system faults or transients which do not otherwise impair reactor operation. One side of each generator output circuit will be grounded. The generator has a brushless exciter with an SCR voltage regulator.Voltage regulation is maintained within +/-2%. The voltage level is adjustableapproximately+/-10%. Each motor is fed from a separate 480 Vac bus. A powersupply from an essential source is not required for these units because thefail-safe design of the plant protection system results in a scram prior to essential bus transfer to the diesel generators.An alternate power source is provided to permit servicing of either motorgenerator set. Manual circuit breakers with a mechanical interlock prevent paralleling a motor generator set and the alternate source while transferring the load between them.The loads for these power supplies are indicated in Drawing NE-36771-4,Section 15. The principal loads on the system are magnetic contactors, AC type solenoid operated air valves, and electronic equipment for radiation and neutron monitoring.Electrical Protection Assemblies provide overvoltage, undervoltage, andunder-frequency protection to components served by these power supplies(Reference 24).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.06Doc Type:Admin Initials:Date:9703 Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 3I/mab8.6.2.1GeneralThe flywheel MG sets are provided to supply continuing AC power availabilityand to provide transient-free power. The use of flywheels sustains energydelivery for short periods of time when input energy is not available. The use of MG sets provide complete isolation from normal transients since there is no opportunity for inductive coupling as there would be with regulating transformers.8.6.2.2Loss of OutputInterruptible Power Supply BusesAs with the other components of the reactor protection systems, a componentfailure can be tolerated without loss of protection and without causing a scram. | |||
This situation is also true with the interruptible AC power supplies. Loss ofoutput of one of the power supplies will result in the loss of functions of all unitsconnected to this bus leaving them in a tripped condition. Thus, if any one of the functions on the second protection bus should trip, a scram would result. | |||
This would occur regardless of whether the trip was spurious or warranted. | |||
Loss of voltage on either of the buses is annunciated in the control room bytripping of all auto scram parameters, providing opportunity for repair withoutshutting the reactor down.Electrical Protection Assemblies monitor the electric power in each of the threesources of power (RPS M-G sets A and B, and the alternate source) to the RPS. Each assembly consists of two identical and redundant packages. Eachpackage includes a circuit breaker and a monitoring module. When abnormalelectric power is detected by either module, the respective circuit breaker will trip and disconnect the RPS from the abnormal power source.Each monitoring module will trip its associated breaker on overvoltage,undervoltage or under frequency. With the protective packages installed,abnormal output type failures (random or seismically caused) in either of thetwo RPS M-G sets (or the alternate supply) results in a trip of either one or both of the two Class 1E protective packages. This tripping interrupts the power to the affected RPS channel, thus producing a scram signal on that channel. A time delay is incorporated in the circuit to prevent spurious actuation. Up to afour-second time delay before circuit breaker tripping will not result in damageto components of the RPS or prevent the RPS from performing its safety functions. | |||
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 3I/mab8.6.3Inspection and TestsThe above equipment is in service during normal plant operation. However, allthe equipment is inspected periodically to check for signs of malfunctioning.Sufficient alarms are provided to inform the operator of any abnormal operating condition. | |||
Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 2SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.7Instrumentation and Control AC Power Supply Systems8.7.1Interruptible AC SystemThe interruptible portion of the instrumentation and control AC power systemprovides AC power to plant AC instrument loads. A single line diagram is shownin Figure 8.7-1.Distribution panel Y20 is supplied from the plant auxiliary system. An automatictransfer to an alternate source within the plant auxiliary system occurs if the original source fails. This panel supplies both critical and noncritical instrumentAC and control loads.8.7.2Uninterruptible AC System8.7.2.1Class 1E SystemThe system is composed of (2) Class IE inverters to provide a Division I and a Division II 120 Vac uninterruptible power source. The Division I inverter (Y71) issupplied by Division I 250 Vdc distribution panel D31 with an alternate AC source to the static switch from essential MCC 134 through a stepdown transformer. | |||
The Division II inverter (Y81) is supplied by Division II 250 Vdc distribution panel D100 with an alternate AC source to the static switch from essential MCC 144through a stepdown transformer. Y71 supplies Class 1E distribution panel Y70and Non-IE distribution panel Y10. Y81 supplies Class IE distribution panel Y80 and Non-IE distribution panel Y30. A single line diagram is shown on Figure 8.7-1.During normal conditions, DC is supplied to the inverters by the Division I andDivision II 250 Vdc battery chargers with their respective batteries as a backup.On loss of DC input, various inverter malfunctions, or overloads, the static switch will transfer to the alternate AC source. An external manual bypass switch may be used to connect the load directly to the alternate source to allow maintenanceon the inverters.As required by Generic Letter 91-11, which documents the NRCs resolution ofGeneric Issues 48 and 49, plant procedures establish time limitations and surveillance requirements for vital instrument buses and associated inverters. | |||
(References 29 and 30).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.07Doc Type:Admin Initials:Date:970305-415 Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 2I/mab8.7.2.2Non-Class 1E SystemThe system is composed of a single module UPS to provide an uninterruptiblepower source primarily to the VAX computer systems. The UPS (Y91) issupplied AC by Load Center 108 with an alternate 480 Vac source from Load Center 107. The 250 Vdc backup is provided to UPS Y91 by No. 17 250 Vdc battery through distribution panel D71. UPS Y91 supplies a 3-phase 480 Vac distribution panel Y94 and also 120/208 Vac distribution panels Y90, Y96,PDS1 and PDS2 through 480 - 120/208 Vac transformers. A single linediagram of the system is shown on Figure 8.7-2.During normal conditions, 480 Vac power is supplied to the rectifier/inverter unitby Load Center 108. On loss of 480 Vac input, the No. 17 battery will supply the power required by the inverter to the loads and on a UPS failure the staticswitch will transfer the load to the alternate source, LC 107. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of10SECTION8PLANTELECTRICALSYSTEMSI/arb8.8ElectricalDesignConsiderations8.8.1DivisionSeparationThedesignandinstallationofcablesandracewaysforthereactorprotectionandengineeredsafeguardsystemsprovidesprotectionandseparationofwiringfor redundantchannelsadequatetoachieveanindependenceoffunctionwhichis compatiblewiththedegreeofsystemandequipmentredundancyinvolved.Thespecificcablesandracewaysinthecategoryforwhichseparationisprovidedincludethoseforcircuitsinvolvedinthecontrol,protection,andsupplyofpowertothereactorprotectionandengineeredsafeguardssystems.Circuits relatedtothesesystems,butforwhichseparationisnotnecessarilyprovided, includecablesandracewaysforinstrumentationandalarmswhichhave informationsignificanceonly,andwhichdonotinvolveautomaticcontrolfunctionsofanykind.Furthermore,separationisnotnecessarilyprovidedforpowercircuitswheretheparticularsystemisfail-safeonlossofpower.Forthosecircuitswhichareinthecategoryrequiringseparation,controlwiring fromthesensorstothelogicdevicesandtothefinalcontrolledelement,and powerwiringfromthesource,throughthecontrollertotheloadapparatus,areroutedsothattheredundantchannelsarephysicallyseparatedbyspaceorbybarriers.Cablesforthereactorprotectionsystemareroutedinacompletelyenclosedmetallicracewaysystemcomposedofrigidsteelconduit,steelboxes, andfittings,steelguttersorcoveredsteeltrays.Thisracewaysystemcontains nocircuitsotherthanfortheprotectionsystem,andprovidescompleteseparationofredundantchannels.Cablesforengineeredsafeguardcircuitsare routedintraysand/orconduitswhichprovideadequateseparationofredundant channels.Controlapparatus,distributionequipment,andpowersourcesare alsoseparated.Thedieselgenerators,essential4160Vacand480Vac switchgear,480VacMCC's,andthestationbatteriesareinseparateareasisolatedbyconcretefloorsorwalls.Controlroompanelscontainingdevicesforredundantchannelsareprovidedwithsteelbarriersseparatingthechannelsor redundantsystemsareseparatedby3feetormore.Localpanelsprovide equivalentseparation.Theplantarrangementissuchthatintheturbine-generatorbuilding,whichhousestheessential4160Vacswitchgear,480Vacloadcenters,and480VacMCCswiththeexceptionofMCCs134and144,theapparatusandconnecting racewaysassociatedwitheachredundantchannelarelocatedondifferentlevels separatedbyareinforcedconcretefloor.Thetwodiesel-generatorsarelocatedinseparateroomsabuttingtheturbine-generatorbuilding. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of10I/arbConnectionsfromthediesel-generators,andrelatedequipment,totheapparatusorracewaysintheturbine-generatorbuildingareinrigidsteelconduitswhicharealsoseparatedfromtheredundantchannelbytheconcretefloor.Wheretheracewaysapproachthecablespreadingroom,thetraysofoppositechannels,ofnecessity,approacheachothermorecloselyand separationhereisprovidedbywallsandbarriers.MCCs134and144arelocatedondifferentfloorsoftheEFTbuildingandareseparatedbyaconcretefloor.Insidethecablespreadingroomseparationisprovidedbyhorizontalorverticalspacingoftheracewaysand/orbytheuseofmetallicbarriers.Inthereactorbuildingwhereracewaysapproachthecablespreadingroomaconcreteblockwallseparatestraysoftheoppositedivision.Inthebalanceofthereactorbuilding,separationisprovidedbyspace,barriers,structures,or combinationsthereof.Exceptforthereactorprotectionsystemwhichhasitsownracewaysystem,thesafeguardcablesarenotseparatedfromnon-safeguardcables.Separationis onlyprovidedbetweencablesinonechannelfromtheirredundantcounterpartsintheotherchannel.TofacilitateidentificationofsafeguardchannelstheredundantsystemsareclassifiedasDivisionsIandII.ApparatusrelatedtothesedivisionsaregenerallyidentifiedAandBoroddandevenrespectively. | |||
Theodd-evendesignationappliesparticularlytothepowersources,switchgear, anddistributionapparatusrelatedtotheredundantpowersystems.Racewaysarealsonumberedodd-even.Generallytheoddracewaysareroutedtotheareasoccupiedbytheodd,DivisionIorAequipment,andtheevenracewaysto theeven,DivisionIIorBequipment.Theseparationoftheoddandeven racewaysinmostcases,isequaltoorbetterthantheminimumdescribed previously.Incongestedareassuchasthecablespreadingroomsomeoddandeventraysareofnecessitymuchcloserthantheminimumallowancebythecriteria.Where thisoccursthesetraysareusedonlyfornon-safeguardcables.Thesafeguard cablesareonlyroutedintrayswhereadequateseparationexists.AlthoughmostDivisionIsafeguardcablesareroutedinoddnumberedracewaysandDivisionIIcablesinevenraceways,thereareoccasionswherethisisnot true.TherearealsopossiblesituationswhereDivisionIandIIcablesoccupy thesameraceway.Thiswouldoccurrarelyandwouldonlyinvolvecablesof unrelatedsystemsandnottheredundantcounterpartsrelatedtothesameprotectivefunction. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of10I/arb8.8.2OriginalSeparationCriteriaForThePrimaryContainmentIsolationSystem(PCIS)andtheEngineeredSafeguardsSystemsTheoriginalseparationrequirementsforthePCISandEngineeredSafeguardsSystemsareshownbelow.Separationrequirementsformissileandfirehazards arestatedintermsofdistance.Theseparationstandardallowsforcloser spacingwheresuitablefireandmissilebarriersexist.a.MechanicalDamage(MissileZone)Thesearezonesofpotentialmissiledamageinthevicinityoflarge rotatingapparatusorhighpressurepiping.Inthesezonesracewaysare separatedbyatleast20feetorbya6inchthickreinforcedconcretewall orfloor.Anexceptiontothisrequirementisinsidethedrywellwhere limitedspace,insomecases,preventsattainmentoftheminimum.Wherethisoccurscareistakentolocatetheredundantracewayssothatasinglemissilewillnotdamagebothchannels.b.FireHazardZoneTypeI.Theseareareaswhereoilorothercombustiblesarepresentin largequantitieswhichcouldsupportadamagingfire.Theroutingofracewaysthroughthesezonesisavoidedwhereverpracticable.Whereitisnecessarytorouteracewaysthroughsuchareasonlythoseforone divisionoftheengineeredsafeguardcablesarelocatedtherein.No cablesareroutedthroughtheturbineoilstorageroom.TypeII.Theseareareaswheretheonlysourceoffireisofanelectricalnatureandcombustiblematerialsconsistprimarilyofelectricalinsulation.Intheseareastraysoftheoppositedivisionareseparatedbyatleast3feethorizontallyor5feetverticallyforstackedtrays.Whena3foot horizontalseparationisnotattainablefireresistantbarriersareprovided betweenthetwotrays.Wheretraysarestackedandmeetthe5footseparationrequirement,thetoptrayisalsoprovidedwithasolidsteelbottomandthebottomtraywithasolidsteelcover.Whentraysof oppositedivisionscrosstheseparationmaybereducedto18inches providedthetraytopandbottomcoversextend5feetormoreeachside ofthecrossing. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of10I/arbc.CableSpreadingRoomThisistheroombelowthemaincontrolroomandcontainscabletrays,conduits,gutters,andboxesusedtoroutecablespassingthroughtheroom,andcablesroutedtothecontrolroomboardsabove.Thecable spreadingroomalsohousesanumberofcontrolorrelaypanelsand instrumentACdistributionpanels.Thecriteriafortrayseparationof3foot horizontally,5footvertically,18inchesatcrossingswithtraybottomsandtopscoveredaspreviouslydescribed,isappliedherealso.Wheretraysofoppositedivisionapproachmorecloselythan3foothorizontally,afire resistantbarrierbetweenthetraysisprovided.Cablesleavingtraysof oppositedivisionsandwhichapproacheachothermorecloselythan3 footarebothruninseparatesteelconduitsorenclosedgutters.d.ControlRoomPanelsNosinglecontrolroompanel(orlocalpanelorinstrumentrack)includes wiringforbothDivisionIandIIunlessthefollowingseparation requirementsaremet.Iftwopanelscontainingcircuitsofdifferentdivisionsarelessthan3feetapart,afirebarriershallbebetweenthetwopanels.Panelendsclosedinsteelendplatesareacceptableaslongasthedivisionalterminalboards andwirewaysareoneinchfromtheplate.Floortopanelbarriersare providedbetweenadjacentpanelshavingclosedends.Apanelmaycontainwiringandcomponentsoftwoengineeredsafeguardssystemsredundanttoeachotherprovidedthatthepanelissubdividedbymeansofafirebarrier.Nocableterminalblocksorother componentsshouldbelocatedlessthanoneinchfromsuchabarrier. | |||
Penetrationofseparationbarrierswithinasubdividedpanelispermitted providedthatsuchpenetrationsaresealedorotherwiseratedsothatan electricalfirecouldnotreasonablypropagatefromonesectiontotheotheranddestroytheprotectivefunction.Incaseswherecircuitsandcomponentssuchasmanualswitches,indicatinglights,andannunciatorsarenotvitaltotheautomaticoperation ofredundantsafetysystems,thesecircuitsandcomponentsmaybe groupedtogetheronthesamecontrolroompanel. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of10I/arb8.8.3FunctionalSeparationInadditiontoprovidingchannelseparationasdescribedabove,theracewaysystemprovidesseparationbyfunctionasfollows:1.MediumVoltagePower13.8KVand4160Vacpowercablesareroutedinconduitsortraysseparatefromthoseforcablesofotherfunctions.2.LowVoltagePowerandControlThisclassificationincludescableswithinsulationratedat600Vacusedfor powerandcontrolcircuitsoperatedat480Vacand120Vacandat125Vdc and250Vdc.Powerandcontrolcablesarenotseparatedfromeachother.Racewaysconsistofladdertypetraysandrigidsteelconduit.3.SignalandInstrumentationCablesofthiscategoryareusedincircuitswhichoperateatverylow energylevelsandwhichmaybenoisesensitivebutwhicharenotnoiseproducers.Racewaysareselectedtominimizenoisepickupandconsistof solidbottomsteeltrayswithsolidcoversorrigidsteelconduit.The instrumentationcablesarenotroutedinthesameracewaysaspowerand controlcables.8.8.4EquipmentIdentificationandConfigurationManagementEquipment,includinglocallymounteddevices,whicharepartofengineered safeguardsystems,isprominentlymarkedwithnameplatesorequivalentmeanswhichuniquelyidentifythemasrequiredbytheplantlabelingandequipmentnumberingprograms.Conduits,cabletrays,boxes,andcablesexceptthosethatarepartoflighting,receptacle,communicationandcomputersystemsareassignedandmarkedwithauniqueidentificationnumber.Thisnumberisgenerallyusedon appropriatedrawings,schedules,listings,andconstructionrecordsandcontrols.Cablesaremarkedattheirends.Theracewayandcablenumberingsystemincorporatesanodd-evensignificancetoaidthedesignerinprovidingtheproperseparationofcablesinredundantsafeguardsystems.Strictadministrativecontrolscombinedwiththeproperusageofthedesigndrawings,schedules,andlistingsandtheidentificationmarkingofequipment, raceways,andcablesfacilitatesafetyduringplantoperationandmaintenance.Followingaredescribedanddiscussedtheprincipaldesigndocumentswhichprovidetheinformationnecessarytotheimplementationoftheadministrative controls.a.ConduitandTrayDrawings-Thesedrawingsidentifyandshowthephysicallocationofelectricalraceways,equipmentanddevicestowhichelectricalconnectionsaremade.01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of10I/arbb.Schematic(Elementary)Diagrams-Thesedrawings,inadditiontodefiningcircuitfunction,identifycaseswheremandatoryseparationofsafeguardcablesisrequiredandusually,bymeansoftheodd-evenschemenumber,indicatethesafeguardsdivisionofthesystemtowhicheachcableisrelated.CircuitScheduleThisscheduleincludesforeachcable,thecablenumber,schemenumber,cabletype,andadetailedroutingthroughracewaysfromorigintodestination.RacewaySchedule Thisscheduleincludesforeachraceway,theracewaynumber,type,size,percentfill,andalistingofcablesroutedtherein.ConnectionDiagramsThesedrawingsshowexternalconnectionstomajorapparatusandmostlocaldevices.Thecablenumbers,wirenumbers,andterminalsareshownonthesedrawings.CableListing-SchemeNumberSequenceThecableschedulemaybesortedandgroupedinschemenumbersequence.Referencetothisdocumentandtherelatedschematic(elementary)diagrampermitstheidentificationofcablesassociatedwithaparticularsystem.Further,thislistingmaybeusedtoidentifysafeguardcablesandtheirsafeguarddivision.8.8.5ElectricalPenetrationsTherearevariouscontainment(drywellandwetwell)electricalpenetrationassemblies.Mostarelocatedatnearlythesameelevationandinfourgroups aroundthedrywellperipheryapproximately90oapart.FourassembliesareusedsolelyfortheCRDpositioncables,fourforneutronmonitoringcables,two for4160Vacpowertotherecirculationpumps,oneformiscellaneousthermocouplesandotherlowlevelsignalcircuits,oneforlowlevelsignalcircuits,andthreeformiscellaneouspowerandcontrol.Apparatusordevicesinsidethedrywell,thewiringtowhichrequiresseparation,includeanumberofneutron monitoringcablesassociatedwiththeRPS,severalvalvepositionswitches whichserveasscramsensorsfortheRPS,safeguardcablesrelatedtotheRCIC,RHRandCoreSpraySystems.Althoughonegroupofpenetrationassembliesisseparatedfromtheothersontheexteriorofthedrywellbyconcretewalls,nobarriersexistinsidethedrywell.Separationisprovidedbyvirtueofthespacingofgroupswhichareabout40feet apart. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage7of10I/arbTheneutronmonitoringcablesaredividedintofourchannels.Eachchannelisroutedthroughaseparatepenetrationassembly.Threeoftheseassembliescontainonlyneutronmonitoringcables.Thefourthalsocontainsfourshieldedcablesusedforvibrationdetectorsignalsofextremelylowenergylevel.The fourassembliesarearrangedinpairs,eachpairondiametricallyoppositesides ofthedrywell.Thecablestoandfromeachofthesepenetrations,beinginthe RPSareinstalledincompletelyenclosedracewaysystemsaspreviouslydescribed.Thescramsensorcablesarealsoinfourchannelswhichareroutedthroughtwodiametricallyoppositepenetrationassemblies.Eachassemblycontainstwo groupsofconductorswhichareusedonlyfortheRPScircuits.Eachgroupisseparatedfromtheothergroupandfromotherconductorsinthepenetration assemblybycompleteenclosureinmetallicconduitinsideandoutsidethepenetrationassembly.Theotherconductorsinthesetwopenetration assembliesareusedformiscellaneouspowerandcontrolapplications,including someofthetwo-channelsafeguardservices.Redundantchannelsutilizethediametricallyoppositepenetrationassemblies.8.8.6RacewaysRacewaysofseveraltypesareusedthroughouttheplantfortheroutingofpower,control,andinstrumentcables.Cabletrayisusedforroutingthemain concentrationsofcablesaroundtheplant.Cabletraysaresteelandare manufacturedandtestedinaccordancewithNEMACableTrayStandardsVE-1 (Reference49).Thetraysaredesignedtowithstanda100lb/ftloadingwithdeflectionnotexceeding0.25inchforan8footspan.Traysupportsarespaced8footorcloserandarepredominantlyconstructedofunistrutchannels,inserts andfittings.Traysforpowerandcontrolgenerallyareoftheladdertype.Covers areprovidedwherecablesmaybesubjecttomechanicaldamageorinareas whereuncoveredtraysmighttendtocollectdebris.Traysforinstrumentationaresolidbottom,andprovidedwithcoverstoreduceelectricalnoisepickup. | |||
Solidbottomtrayswithcoversarealsousedforpowerandcontrolcablesin congestedareaswheretheminimumspacingforopentrayscannotbeobtained. | |||
Wheretraysinarunarestacked,theverticalspacingisgenerally1footor greater.Exceptforthesafeguardtrayspreviouslydiscussed,theminimumhorizontalseparationisdeterminedbyaccessibilityrequirementsduringandafterconstruction.Galvanizedrigidsteelconduitisusedforcablesofalltypesroutedfromtraystoapparatusandlocaldevices,andforotherexposedruns.Rigidsteelconduitisalsousedformanyembeddedandundergroundruns.Thinwallconduitisused onlyforlightingandcommunicationscircuits.Shortrunsofflexible,liquid-tight conduitareusedwherevibrationmaybeencounteredortofacilitateremovaloftheconnecteddevice.Fittingsandboxesaremadeofsteel.Someofthe4inchandlargerrunsembeddedinconcretearemadewithplasticconduit.Someundergroundrunsaredirectlyburiedintheearthandareprotectedbyaheavy woodplank.Galvanizedsteelgutterisusedinsomeapplications. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage8of10I/arbWherepractical,conduitfillisheldwithinthepercentagerecommendedbytheNationalElectricalCode(NEC).Trayfillistrackedandcontrolledtolimitexcessiveconcentrationsofheatproducingcablesandexcessivesidewallpressureexertedonindividualcablesbyothercables.8.8.7CablesCablesarequalifiedfortheirspecificapplications.Examplesofcabletypesusedforvariousservicesareasfollows:13.8KV15KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.4160Vac5KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.600Vac(orOzoneresistantbutylrubberinsulation,neoprenejacket,sizeless)Powerasrequired,No.10AWGminimum.Somepowercablesinside Cablethedrywellusecross-linkedpolyethyleneinsulation.CableswithEPRinsulation,hypalonjacketarealsoused.Feeder cablestoMCC115andMCC124arequalifiedforthespecific undergroundinstallationinvolvedControlMostlymulti-conductorNo.14AWGwith20milsPEinsulation Cableand10milsPVCjacketonthesingles,andPVCjacketoverall.SomeNo.12AWGandNo.10AWGcontrolcablesareused. | |||
SingleconductorcontrolcablewhereusedisNo.10AWGminimumsize.Controlcablesinsidethedrywellandinsomeotherapplicationsusecross-linkedpolyethyleneinsulationwith aneoprenejacket.SpecialAgreatnumberofspecialcablesforparticularapplicationsare Cableused.Followingaresomeofthemorecommontypes:1.CablesformiscellaneousinstrumentationandcomputerusagearePEinsulated,No.16AWG,braidortapeshield, PVCjacketed.Thermocoupleextensionleadsaresimilar.2.Neutronmonitorcablesarecoaxial,tripleshielded,orshieldedpairs,PEinsulation,shields,PVCjacketoverall.3.CRDpositioncablesinsidethedrywellaremulti-conductorNo.20AWG,cross-linkedpolyethylene,neoprenejacket.4.Specialmulti-conductorcontrolapplications,particularlywhereusedwithseparableconnectorsareNo.16toNo.20 AWG,PEorXLPEinsulatedsometimesshielded,PVCjacketoverall.Inselectingconductorsizes,properconsiderationisgiventotheambienttemperatureandtothetypesofracewaysthroughwhichthecableisrouted.Inmostareasoftheplantthedesignambientistakenas40oC(104F).Higherlocaltemperaturesincertainareasarefactoredinasrequired.Insidethedrywellthedesignambienttemperatureis66C(150F).01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage9of10I/arbForpowercablesinconduitsandtrays,thecablemanufacturer'srecommendations,relevantICEA(formerlyIPCEA)standardsorrelevantindustrystandardsareusedasaguideinselectingtheproperderatingfactor.TheICEAstandardstakesomecreditforadegreeofdiversityintheloadingof thecablesandthefactthatthereareanumberofcontrolcablesandidlepower cableswhichdonotproduceheat.Cableoverloadsarepreventedbytheproperselection,applicationandsettingofprotectiverelays,circuitbreakers,seriestripelementsmotoroverloadheaters,andfuses.Cablesareprotectedagainstdamagefromshortcircuitsbyselectingaconductorwhichwillcarrytheavailablefaultcurrentforthelengthoftimerequiredfortheprotectivedevicetoclearthefault,withoutexceedingthe manufacturer'smaximumshortcircuittemperatureratingfortheconductorinsulation.8.8.8SpecialConsiderationsa.Thenon-safeguardcableinstallationsdonotcompromisethoseprovidedfortheprotectivefunctions.TheRPScablesareintheirownracewaysystemandarenotexposedtocablesofothersystems.Althoughsafeguardcablesandnon-safeguardcablesmayberoutedthroughthesameraceways,thechannelseparationprovidedforthesafeguardcables preventsaccidentsfrominvolvingmorethanoneoftheredundant channels.Thepreviouslydescribedconservativeracewayloading,cable derating,andprotectionagainstelectricalfaults,inconjunctionwiththeassociatedcircuitsanalysis,eliminatesthepossibilityofthesafeguardcablesdescribedinreference6frombeinginvolvedwithfaultsinthenon-vitalcircuits.b.Inconjunctionwiththecomputerprocessedracewayandcircuitschedules,appropriateracewaysandcablesintheplantareassignedanumber.Racewayandcablenumbersincludeanodd-evendesignation,whichgenerallycorrespondstothesystemwithwhichtheyarerelated. | |||
Eachracewayismarkedwithitsidentificationnumber.Thecablenumber isattachedtoeachendofeachcable.Duringthedesignphaseand duringconstructionthecomputerprocessedcircuitandracewayschedulesaretheprimarymeansforcontrollingtheinstallationofRPSandsafeguardcablessothattherequiredchannelseparationisachieved. | |||
Elementarydiagramsorschematicdiagramsforcircuitswhichrequireseparationcarryanotationthatmandatoryseparationoftheredundantfunctionsistobeprovided.Tofacilitatetheroutingseparation,wherepossible,advantageistakenoftheracewaynumberingsystemfor odd-evencables. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage10of10I/arbc.ControlovertheinstallationofcablestoensurethatthedesignrequirementsaremetisprovidedbytheQualityAssuranceProgram.RPSandsafeguardcablesareincludedinthisprogram.Becausesafeguardcablesarenotnecessarilyseparatedfromnon-safeguardcables,racewayscontainingreactorprotection,safeguards,orassociatednon-safeguardscablesareincludedundertheQualityAssurance Program.TheQualityAssuranceProgramassuresthatthecableinstallationshavebeenmadeproperlyandthattheycomplywiththedesignwithrespecttocabletype,identification,routingandconnections, andthattheracewaysareofthecorrecttypesandareproperlyinstalled, andidentified. | |||
SECTION 88.98.9.1 | |||
SECTION 88.10 | |||
SECTION 88.118.11.1 | |||
8.11.2 | |||
8.11.3 | |||
SECTION 88.12 | |||
SECTION 88.13 | |||
Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of6SECTION8PLANTELECTRICALSYSTEMSI/arbFIGURES Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of6I/arbFigure8.3-2LPCISwingBusDegradedPowerTransferSchemeLPCISwingBusDegradedPowerTransferSchemeActuationofanyoftheserelayswillcausetrippingrelay(94P)toopenACB52-3300andcloseACB52-4300.ThistransfersthepowersupplytotheswingbusfromDivisionItoDivsionII.FromDiv.IMCC133A(480V)LPCIInjectionValvesLoopAMCC133BLoadCenter103CoreSprayInjection Valves27-33B27-33A59N-3381-3327-33480/120P.T.ACB52-307(N.C.)ACB52-3300(N.C.)94P(480V)FromDiv.IILoadCenter104ACB52-407(N.C.)ACB52-4300(N.O.)MCC143BMCC143ALPCIInjectionValves LoopBCoreSprayInjectionValvesRelayDesignations27-33A:LossofVoltagewith#11EDGOutputBreakerClosed27-33B:DegradedVoltagewith#11EDGOutputBreakerClosed 59N-33:OverVoltagewith#11EDGOutputBreakerClosed81-33:OutofFrequencywith#11EDGOutputBreakerClosed27-33:LossofNormalVoltage 94P:TrippingRelayTRIPCLOSE Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of6I/arbFigure8.4-1DieselGenerationSystemOneLineDiagramToAuxiliaryTransformer(2R) orReserveTransformer(1R)ToReserveAuxiliaryPower Transformer(1AR)No.11DieselGenerator 3125KVA 4.16KV0.80PFNo.12DieselGenerator3125KVA 4.16KV0.80PFToReserveAuxiliaryPower Transformer(1AR)ToAuxiliary Transformer(2R) orReserveTransformer(1R)LC109SPAREBREAKERCIRC.WATERPUMP1250HPLC107LC101TURBINEAUXOILPUMP250HPLC103RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HPCORESPRAYPUMP800HPRHRPUMP600HP*RHRPUMP600HP*INTERTIEFEEDERLC104RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HP CORESPRAYPUMP800HPRHRPUMP600HP* | |||
RHRPUMP600HP*INTERTIEFEEDERLC102LC108CIRCWATERPUMP1250HPSPAREBREAKERSPAREBREAKERBUSNo.13BUSNo.15BUSNo.16BUSNo.14*NOTE:MONTICELLO'SINVENTORYINCLUDESBOTH600AND700HPMOTORSTHATMAYBEUSEDONANYOFTHEFOURRHRPUMPS.01351161 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of6I/arbFigure8.5-4#17-250VdcDistributionPanel(D71)01298950 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of6I/arbFigure8.7-1InstrumentACandUninterruptibleACDistributionSystemSingleLineDiagram120VAC1120VAC1 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of6I/arbFigure8.7-2Y91UninterruptibleACDistributionSystemSingleLineDiagram13DGC40PDS1Y96C40PDS2FILTERNY96XY96BXY96ANPDS96COMPUTEREQUIPMENT3RDFLOORH&VRM2NDADDITIONOLDH&VRM3RDFLOOREASTELECTRICAL EQUIPMENTRMNPDS1ANPDS1NPDS2ANPDS2XPDS2XPDS1Y94480VACY93MAINTENANCEBYPASSSWITCHY90120/208VACY91UPSD71#17BATTERY 250VDC52-70452-80452-80152-701LC108LC10752-71052-711COMPUTERRMXY90 SECTION 8 | |||
Revision 22USAR 8.1MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 1SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.1SummaryThe plant electrical power system is designed to provide a diversity of dependablepower sources which are physically isolated so that any one failure affecting one source of supply will not propagate to alternate sources. The plant auxiliaryelectrical power systems are designed to provide electrical and physicalindependence and adequate power supplies for startup, operation, shutdown, and for other plant requirements which are important to safety.In the event of a loss or degradation of all off-site power sources, auxiliary powerwill be supplied from diesel generators located on the site. These power sources are physically independent from any normal power system. Each power source, up to the point of its connection to the auxiliary power bus, is capable of completeand rapid electrical isolation from any other sources. Loads important to plantsafety are split and diversified between switchgear sections and means are provided for rapid location and isolation of system faults. Plant batteries are provided as a reliable source of control power for specific engineered safeguards and other functions required when AC power is not available.FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.01Doc Type:Admin Initials:Date:9703 Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of2SECTION8PLANTELECTRICALSYSTEMSI/eak8.2TransmissionSystem8.2.1NetworkInterconnectionsOutputoftheMonticelloNuclearGeneratingPlantisdeliveredtoa345/230/115/13.8KVswitchyardlocatedontheplantsite.DrawingNH-178635, Section15,showstheonelinediagramfortheMonticelloplantandits connectionstothetransmissionsystem.The345KVportionoftheswitchyardhaspositionsforconnectingthegeneratoroutput,threetransmissionlines,a345-230-13.8KVautotransformera345-13.8KVtransformer,a345-34.5KVtransformer,anda345-115-13.8KV autotransformer.The345KVbusandcircuitbreakerarrangementisa breaker-and-one-halfsystem.One345KVtransmissionlineisroutedtoconnect intothe345KVlooparoundtheTwinCitiesMetropolitanAreaattheElmCreekSubstation.Thesecondlineconnectstothe345KVtransmissionsystematSherburneCountySubstation.Thethirdlineconnectstothe345KVQuarry Substation.The230KVportionoftheswitchyardisprovidedtoestablishaninterconnectionwiththetransmissionsystemoftheGreatRiverEnergy.Anautotransformerconnectsthe345KVand230KVbusses.The115KVportionoftheswitchyardisconnectedtothe345KVbusthroughanautotransformer.The115KVbusisarrangedinaringbusconfiguration.In additiontotheautotransformerconnectiontothe115KVbus,therearethree transmissionlineconnectionsandaconnectiontoaplantauxiliarytransformer.Oneofthethreetransmissionlinesconnectsintothe115KVtransmission systematLakePulaskiSubstationandatDickinsonSubstation,anotheratHassanSubstation,andthethird115KVlineconnectstotheLibertysubstation.The13.8KVportionoftheswitchyardisprovidedtoestablishreliablepowersourcestovariousplantequipment.Theseincludetheplantauxiliaryreservetransformer(1AR);dischargestructuretransformers(X7,X8);coolingtowerfan transformers(X50,X60,X70,X80);transformerXP91whichpowersthe hydrogenwaterchemistrycryogenicsystempanelandanalternatefeed (throughtransformer6)tothetrainingcenter. | |||
Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of2I/eakThesix(345KVand115KV)transmissionlineconnectionstotheswitchyardareallconnectedintotheXcelEnergyinterconnectedtransmissiongrid.Theirpointsofconnectiontothegridarearrangedbyroutesandintra-right-of-wayspacingtominimizemultiplelineoutageswhileperformingtherequirementof deliveringpowertolocationswhichbestsatisfysystemgrowthneeds.The345KVand115KVlines,aswellasthelinestowhichtheyinterconnect,are designedandbuilttoexceedtherequirementsoftheNationalElectricSafetyCodeforheavyloadingdistricts,GradeBconstruction(Reference41).Lightningperformancedesignofthetransmissionlinesisbasedonlessthanoneoutage per100milesperyear.ThesixXcelEnergytransmissionlinesleavetheMonticellosubstationthroughfourseparaterights-of-way:SherburneCountylinecorridor;Libertylinecorridor; Quarrycorridor;andacommoncorridorfortheElmCreek,Dickinson-LakePulaski,andHassanlines.Theserights-of-wayareconsideredindependentastheyaregreaterthan1/4mileapartatadistanceof1milefromtheplant.Threetransformersareprovidedtosupplytheplantwithoffsitepowerfromthesubstation.Allthreesourcescanindependentlyprovideadequatepowerforthe plant'ssafety-relatedloads.Thesetransformersandtheirinterconnectionsto thesubstationareasfollows:Theprimarystationauxiliarytransformer,2R,isfedfrom345KVBusNo.1via345KVto34.5KVtransformer2RS,andundergroundcablingfromthesubstationtotheareanorthwestoftheturbinebuildingwhere2Rtransformer islocated.2Rtransformerisofadequatesizetoprovidetheplant'sfull auxiliaryloadrequirements.Thereservetransformer,1R,isfedfromthe115KVsubstationviaanoverheadlinefromthesubstationtotheareanorthwestoftheturbinebuildingwhere1Rtransformerislocated.1Rtransformerisofadequatesizetoprovidetheplant'sfullauxiliaryloadrequirements.Thereserveauxiliarytransformer,1AR,islocatedsouthwestofthereactorbuildingandmaybefedfromtwoseparate13.8KVsourcesinthe substation.Onemethodofsupplying1ARtransformerisfromthetertiary windingof#10transformer,theauto-transformerwhichinterconnectsthe345KVand115KVsystems.Powerisroutedfromthetertiarywindingof10transformerto1ARviacircuitbreaker1N2andundergroundcablingfromthe substationto1ARtransformer.Thealternatemethodoffeeding1ARisfrom the345KVsubstationvia345KVto13.8KVtransformer1ARS,circuit breaker1N6,andundergroundcablingfromthesubstationto1AR.Circuitbreakers1N2and1N6areinterlockedtopreventhavingbothbreakerssimultaneouslyintheclosedposition.1ARtransformerissizedtoprovide onlytheplant'sessential4160Vacbusesandconnectedloads.01405303 SECTION 88.38.3.1 | |||
8.3.2 | |||
8.3.3 | |||
8.3.4 | |||
8.3.5 | |||
bus tie breaker for Load Centers 101 and 102 is physically located in LC-102 | |||
SECTION 88.48.4.1 | |||
8.4.2 | |||
NOTE 1:NOTE 2:NOTE 3:NOTE 4:NOTE 5:NOTE 6:NOTE 7:NOTE 8: | |||
NOTE 9:NOTE 10: | |||
NOTE 11:NOTE 12:NOTE 13:NOTE 14: | |||
SECTION 88.5 | |||
8.5.1 | |||
8.5.2 | |||
8.5.3 | |||
8.5.4 | |||
8.5.5 | |||
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 3SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.6Reactor Protection System Power Supplies8.6.1Design BasisTwo motor generator sets provide AC power for operation of the ReactorProtection System. These sets are powered from 480 Vac buses and are used to supply power to the scram logic channels as well as neutron and radiationmonitoring systems. These sets are termed interruptible power supplies sinceloss of AC power to them causes a delayed loss of output as the inertial energy of the flywheel is converted to power for the connected loads.These systems are designed to provide a continued output of 120 Vac powerthat is free of transients and is extremely reliable. Switching transients andmomentary losses of input power will not cause substantial changes in outputvoltage or frequency.8.6.2DescriptionInterruptible Power SuppliesThe normal power supply will consist of two motor generator sets, eachconsisting of a three-phase induction motor driving a 120 Vac single-phasegenerator with flywheel. The flywheel provides energy to maintain generator output during momentary system faults or transients which do not otherwise impair reactor operation. One side of each generator output circuit will be grounded. The generator has a brushless exciter with an SCR voltage regulator.Voltage regulation is maintained within +/-2%. The voltage level is adjustableapproximately+/-10%. Each motor is fed from a separate 480 Vac bus. A powersupply from an essential source is not required for these units because thefail-safe design of the plant protection system results in a scram prior to essential bus transfer to the diesel generators.An alternate power source is provided to permit servicing of either motorgenerator set. Manual circuit breakers with a mechanical interlock prevent paralleling a motor generator set and the alternate source while transferring the load between them.The loads for these power supplies are indicated in Drawing NE-36771-4,Section 15. The principal loads on the system are magnetic contactors, AC type solenoid operated air valves, and electronic equipment for radiation and neutron monitoring.Electrical Protection Assemblies provide overvoltage, undervoltage, andunder-frequency protection to components served by these power supplies(Reference 24).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.06Doc Type:Admin Initials:Date:9703 Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 3I/mab8.6.2.1GeneralThe flywheel MG sets are provided to supply continuing AC power availabilityand to provide transient-free power. The use of flywheels sustains energydelivery for short periods of time when input energy is not available. The use of MG sets provide complete isolation from normal transients since there is no opportunity for inductive coupling as there would be with regulating transformers.8.6.2.2Loss of OutputInterruptible Power Supply BusesAs with the other components of the reactor protection systems, a componentfailure can be tolerated without loss of protection and without causing a scram. | |||
This situation is also true with the interruptible AC power supplies. Loss ofoutput of one of the power supplies will result in the loss of functions of all unitsconnected to this bus leaving them in a tripped condition. Thus, if any one of the functions on the second protection bus should trip, a scram would result. | |||
This would occur regardless of whether the trip was spurious or warranted. | |||
Loss of voltage on either of the buses is annunciated in the control room bytripping of all auto scram parameters, providing opportunity for repair withoutshutting the reactor down.Electrical Protection Assemblies monitor the electric power in each of the threesources of power (RPS M-G sets A and B, and the alternate source) to the RPS. Each assembly consists of two identical and redundant packages. Eachpackage includes a circuit breaker and a monitoring module. When abnormalelectric power is detected by either module, the respective circuit breaker will trip and disconnect the RPS from the abnormal power source.Each monitoring module will trip its associated breaker on overvoltage,undervoltage or under frequency. With the protective packages installed,abnormal output type failures (random or seismically caused) in either of thetwo RPS M-G sets (or the alternate supply) results in a trip of either one or both of the two Class 1E protective packages. This tripping interrupts the power to the affected RPS channel, thus producing a scram signal on that channel. A time delay is incorporated in the circuit to prevent spurious actuation. Up to afour-second time delay before circuit breaker tripping will not result in damageto components of the RPS or prevent the RPS from performing its safety functions. | |||
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 3I/mab8.6.3Inspection and TestsThe above equipment is in service during normal plant operation. However, allthe equipment is inspected periodically to check for signs of malfunctioning.Sufficient alarms are provided to inform the operator of any abnormal operating condition. | |||
Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 2SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.7Instrumentation and Control AC Power Supply Systems8.7.1Interruptible AC SystemThe interruptible portion of the instrumentation and control AC power systemprovides AC power to plant AC instrument loads. A single line diagram is shownin Figure 8.7-1.Distribution panel Y20 is supplied from the plant auxiliary system. An automatictransfer to an alternate source within the plant auxiliary system occurs if the original source fails. This panel supplies both critical and noncritical instrumentAC and control loads.8.7.2Uninterruptible AC System8.7.2.1Class 1E SystemThe system is composed of (2) Class IE inverters to provide a Division I and a Division II 120 Vac uninterruptible power source. The Division I inverter (Y71) issupplied by Division I 250 Vdc distribution panel D31 with an alternate AC source to the static switch from essential MCC 134 through a stepdown transformer. | |||
The Division II inverter (Y81) is supplied by Division II 250 Vdc distribution panel D100 with an alternate AC source to the static switch from essential MCC 144through a stepdown transformer. Y71 supplies Class 1E distribution panel Y70and Non-IE distribution panel Y10. Y81 supplies Class IE distribution panel Y80 and Non-IE distribution panel Y30. A single line diagram is shown on Figure 8.7-1.During normal conditions, DC is supplied to the inverters by the Division I andDivision II 250 Vdc battery chargers with their respective batteries as a backup.On loss of DC input, various inverter malfunctions, or overloads, the static switch will transfer to the alternate AC source. An external manual bypass switch may be used to connect the load directly to the alternate source to allow maintenanceon the inverters.As required by Generic Letter 91-11, which documents the NRCs resolution ofGeneric Issues 48 and 49, plant procedures establish time limitations and surveillance requirements for vital instrument buses and associated inverters. | |||
(References 29 and 30).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.07Doc Type:Admin Initials:Date:970305-415 Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 2I/mab8.7.2.2Non-Class 1E SystemThe system is composed of a single module UPS to provide an uninterruptiblepower source primarily to the VAX computer systems. The UPS (Y91) issupplied AC by Load Center 108 with an alternate 480 Vac source from Load Center 107. The 250 Vdc backup is provided to UPS Y91 by No. 17 250 Vdc battery through distribution panel D71. UPS Y91 supplies a 3-phase 480 Vac distribution panel Y94 and also 120/208 Vac distribution panels Y90, Y96,PDS1 and PDS2 through 480 - 120/208 Vac transformers. A single linediagram of the system is shown on Figure 8.7-2.During normal conditions, 480 Vac power is supplied to the rectifier/inverter unitby Load Center 108. On loss of 480 Vac input, the No. 17 battery will supply the power required by the inverter to the loads and on a UPS failure the staticswitch will transfer the load to the alternate source, LC 107. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of10SECTION8PLANTELECTRICALSYSTEMSI/arb8.8ElectricalDesignConsiderations8.8.1DivisionSeparationThedesignandinstallationofcablesandracewaysforthereactorprotectionandengineeredsafeguardsystemsprovidesprotectionandseparationofwiringfor redundantchannelsadequatetoachieveanindependenceoffunctionwhichis compatiblewiththedegreeofsystemandequipmentredundancyinvolved.Thespecificcablesandracewaysinthecategoryforwhichseparationisprovidedincludethoseforcircuitsinvolvedinthecontrol,protection,andsupplyofpowertothereactorprotectionandengineeredsafeguardssystems.Circuits relatedtothesesystems,butforwhichseparationisnotnecessarilyprovided, includecablesandracewaysforinstrumentationandalarmswhichhave informationsignificanceonly,andwhichdonotinvolveautomaticcontrolfunctionsofanykind.Furthermore,separationisnotnecessarilyprovidedforpowercircuitswheretheparticularsystemisfail-safeonlossofpower.Forthosecircuitswhichareinthecategoryrequiringseparation,controlwiring fromthesensorstothelogicdevicesandtothefinalcontrolledelement,and powerwiringfromthesource,throughthecontrollertotheloadapparatus,areroutedsothattheredundantchannelsarephysicallyseparatedbyspaceorbybarriers.Cablesforthereactorprotectionsystemareroutedinacompletelyenclosedmetallicracewaysystemcomposedofrigidsteelconduit,steelboxes, andfittings,steelguttersorcoveredsteeltrays.Thisracewaysystemcontains nocircuitsotherthanfortheprotectionsystem,andprovidescompleteseparationofredundantchannels.Cablesforengineeredsafeguardcircuitsare routedintraysand/orconduitswhichprovideadequateseparationofredundant channels.Controlapparatus,distributionequipment,andpowersourcesare alsoseparated.Thedieselgenerators,essential4160Vacand480Vac switchgear,480VacMCC's,andthestationbatteriesareinseparateareasisolatedbyconcretefloorsorwalls.Controlroompanelscontainingdevicesforredundantchannelsareprovidedwithsteelbarriersseparatingthechannelsor redundantsystemsareseparatedby3feetormore.Localpanelsprovide equivalentseparation.Theplantarrangementissuchthatintheturbine-generatorbuilding,whichhousestheessential4160Vacswitchgear,480Vacloadcenters,and480VacMCCswiththeexceptionofMCCs134and144,theapparatusandconnecting racewaysassociatedwitheachredundantchannelarelocatedondifferentlevels separatedbyareinforcedconcretefloor.Thetwodiesel-generatorsarelocatedinseparateroomsabuttingtheturbine-generatorbuilding. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of10I/arbConnectionsfromthediesel-generators,andrelatedequipment,totheapparatusorracewaysintheturbine-generatorbuildingareinrigidsteelconduitswhicharealsoseparatedfromtheredundantchannelbytheconcretefloor.Wheretheracewaysapproachthecablespreadingroom,thetraysofoppositechannels,ofnecessity,approacheachothermorecloselyand separationhereisprovidedbywallsandbarriers.MCCs134and144arelocatedondifferentfloorsoftheEFTbuildingandareseparatedbyaconcretefloor.Insidethecablespreadingroomseparationisprovidedbyhorizontalorverticalspacingoftheracewaysand/orbytheuseofmetallicbarriers.Inthereactorbuildingwhereracewaysapproachthecablespreadingroomaconcreteblockwallseparatestraysoftheoppositedivision.Inthebalanceofthereactorbuilding,separationisprovidedbyspace,barriers,structures,or combinationsthereof.Exceptforthereactorprotectionsystemwhichhasitsownracewaysystem,thesafeguardcablesarenotseparatedfromnon-safeguardcables.Separationis onlyprovidedbetweencablesinonechannelfromtheirredundantcounterpartsintheotherchannel.TofacilitateidentificationofsafeguardchannelstheredundantsystemsareclassifiedasDivisionsIandII.ApparatusrelatedtothesedivisionsaregenerallyidentifiedAandBoroddandevenrespectively. | |||
Theodd-evendesignationappliesparticularlytothepowersources,switchgear, anddistributionapparatusrelatedtotheredundantpowersystems.Racewaysarealsonumberedodd-even.Generallytheoddracewaysareroutedtotheareasoccupiedbytheodd,DivisionIorAequipment,andtheevenracewaysto theeven,DivisionIIorBequipment.Theseparationoftheoddandeven racewaysinmostcases,isequaltoorbetterthantheminimumdescribed previously.Incongestedareassuchasthecablespreadingroomsomeoddandeventraysareofnecessitymuchcloserthantheminimumallowancebythecriteria.Where thisoccursthesetraysareusedonlyfornon-safeguardcables.Thesafeguard cablesareonlyroutedintrayswhereadequateseparationexists.AlthoughmostDivisionIsafeguardcablesareroutedinoddnumberedracewaysandDivisionIIcablesinevenraceways,thereareoccasionswherethisisnot true.TherearealsopossiblesituationswhereDivisionIandIIcablesoccupy thesameraceway.Thiswouldoccurrarelyandwouldonlyinvolvecablesof unrelatedsystemsandnottheredundantcounterpartsrelatedtothesameprotectivefunction. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of10I/arb8.8.2OriginalSeparationCriteriaForThePrimaryContainmentIsolationSystem(PCIS)andtheEngineeredSafeguardsSystemsTheoriginalseparationrequirementsforthePCISandEngineeredSafeguardsSystemsareshownbelow.Separationrequirementsformissileandfirehazards arestatedintermsofdistance.Theseparationstandardallowsforcloser spacingwheresuitablefireandmissilebarriersexist.a.MechanicalDamage(MissileZone)Thesearezonesofpotentialmissiledamageinthevicinityoflarge rotatingapparatusorhighpressurepiping.Inthesezonesracewaysare separatedbyatleast20feetorbya6inchthickreinforcedconcretewall orfloor.Anexceptiontothisrequirementisinsidethedrywellwhere limitedspace,insomecases,preventsattainmentoftheminimum.Wherethisoccurscareistakentolocatetheredundantracewayssothatasinglemissilewillnotdamagebothchannels.b.FireHazardZoneTypeI.Theseareareaswhereoilorothercombustiblesarepresentin largequantitieswhichcouldsupportadamagingfire.Theroutingofracewaysthroughthesezonesisavoidedwhereverpracticable.Whereitisnecessarytorouteracewaysthroughsuchareasonlythoseforone divisionoftheengineeredsafeguardcablesarelocatedtherein.No cablesareroutedthroughtheturbineoilstorageroom.TypeII.Theseareareaswheretheonlysourceoffireisofanelectricalnatureandcombustiblematerialsconsistprimarilyofelectricalinsulation.Intheseareastraysoftheoppositedivisionareseparatedbyatleast3feethorizontallyor5feetverticallyforstackedtrays.Whena3foot horizontalseparationisnotattainablefireresistantbarriersareprovided betweenthetwotrays.Wheretraysarestackedandmeetthe5footseparationrequirement,thetoptrayisalsoprovidedwithasolidsteelbottomandthebottomtraywithasolidsteelcover.Whentraysof oppositedivisionscrosstheseparationmaybereducedto18inches providedthetraytopandbottomcoversextend5feetormoreeachside ofthecrossing. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of10I/arbc.CableSpreadingRoomThisistheroombelowthemaincontrolroomandcontainscabletrays,conduits,gutters,andboxesusedtoroutecablespassingthroughtheroom,andcablesroutedtothecontrolroomboardsabove.Thecable spreadingroomalsohousesanumberofcontrolorrelaypanelsand instrumentACdistributionpanels.Thecriteriafortrayseparationof3foot horizontally,5footvertically,18inchesatcrossingswithtraybottomsandtopscoveredaspreviouslydescribed,isappliedherealso.Wheretraysofoppositedivisionapproachmorecloselythan3foothorizontally,afire resistantbarrierbetweenthetraysisprovided.Cablesleavingtraysof oppositedivisionsandwhichapproacheachothermorecloselythan3 footarebothruninseparatesteelconduitsorenclosedgutters.d.ControlRoomPanelsNosinglecontrolroompanel(orlocalpanelorinstrumentrack)includes wiringforbothDivisionIandIIunlessthefollowingseparation requirementsaremet.Iftwopanelscontainingcircuitsofdifferentdivisionsarelessthan3feetapart,afirebarriershallbebetweenthetwopanels.Panelendsclosedinsteelendplatesareacceptableaslongasthedivisionalterminalboards andwirewaysareoneinchfromtheplate.Floortopanelbarriersare providedbetweenadjacentpanelshavingclosedends.Apanelmaycontainwiringandcomponentsoftwoengineeredsafeguardssystemsredundanttoeachotherprovidedthatthepanelissubdividedbymeansofafirebarrier.Nocableterminalblocksorother componentsshouldbelocatedlessthanoneinchfromsuchabarrier. | |||
Penetrationofseparationbarrierswithinasubdividedpanelispermitted providedthatsuchpenetrationsaresealedorotherwiseratedsothatan electricalfirecouldnotreasonablypropagatefromonesectiontotheotheranddestroytheprotectivefunction.Incaseswherecircuitsandcomponentssuchasmanualswitches,indicatinglights,andannunciatorsarenotvitaltotheautomaticoperation ofredundantsafetysystems,thesecircuitsandcomponentsmaybe groupedtogetheronthesamecontrolroompanel. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of10I/arb8.8.3FunctionalSeparationInadditiontoprovidingchannelseparationasdescribedabove,theracewaysystemprovidesseparationbyfunctionasfollows:1.MediumVoltagePower13.8KVand4160Vacpowercablesareroutedinconduitsortraysseparatefromthoseforcablesofotherfunctions.2.LowVoltagePowerandControlThisclassificationincludescableswithinsulationratedat600Vacusedfor powerandcontrolcircuitsoperatedat480Vacand120Vacandat125Vdc and250Vdc.Powerandcontrolcablesarenotseparatedfromeachother.Racewaysconsistofladdertypetraysandrigidsteelconduit.3.SignalandInstrumentationCablesofthiscategoryareusedincircuitswhichoperateatverylow energylevelsandwhichmaybenoisesensitivebutwhicharenotnoiseproducers.Racewaysareselectedtominimizenoisepickupandconsistof solidbottomsteeltrayswithsolidcoversorrigidsteelconduit.The instrumentationcablesarenotroutedinthesameracewaysaspowerand controlcables.8.8.4EquipmentIdentificationandConfigurationManagementEquipment,includinglocallymounteddevices,whicharepartofengineered safeguardsystems,isprominentlymarkedwithnameplatesorequivalentmeanswhichuniquelyidentifythemasrequiredbytheplantlabelingandequipmentnumberingprograms.Conduits,cabletrays,boxes,andcablesexceptthosethatarepartoflighting,receptacle,communicationandcomputersystemsareassignedandmarkedwithauniqueidentificationnumber.Thisnumberisgenerallyusedon appropriatedrawings,schedules,listings,andconstructionrecordsandcontrols.Cablesaremarkedattheirends.Theracewayandcablenumberingsystemincorporatesanodd-evensignificancetoaidthedesignerinprovidingtheproperseparationofcablesinredundantsafeguardsystems.Strictadministrativecontrolscombinedwiththeproperusageofthedesigndrawings,schedules,andlistingsandtheidentificationmarkingofequipment, raceways,andcablesfacilitatesafetyduringplantoperationandmaintenance.Followingaredescribedanddiscussedtheprincipaldesigndocumentswhichprovidetheinformationnecessarytotheimplementationoftheadministrative controls.a.ConduitandTrayDrawings-Thesedrawingsidentifyandshowthephysicallocationofelectricalraceways,equipmentanddevicestowhichelectricalconnectionsaremade.01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of10I/arbb.Schematic(Elementary)Diagrams-Thesedrawings,inadditiontodefiningcircuitfunction,identifycaseswheremandatoryseparationofsafeguardcablesisrequiredandusually,bymeansoftheodd-evenschemenumber,indicatethesafeguardsdivisionofthesystemtowhicheachcableisrelated.CircuitScheduleThisscheduleincludesforeachcable,thecablenumber,schemenumber,cabletype,andadetailedroutingthroughracewaysfromorigintodestination.RacewaySchedule Thisscheduleincludesforeachraceway,theracewaynumber,type,size,percentfill,andalistingofcablesroutedtherein.ConnectionDiagramsThesedrawingsshowexternalconnectionstomajorapparatusandmostlocaldevices.Thecablenumbers,wirenumbers,andterminalsareshownonthesedrawings.CableListing-SchemeNumberSequenceThecableschedulemaybesortedandgroupedinschemenumbersequence.Referencetothisdocumentandtherelatedschematic(elementary)diagrampermitstheidentificationofcablesassociatedwithaparticularsystem.Further,thislistingmaybeusedtoidentifysafeguardcablesandtheirsafeguarddivision.8.8.5ElectricalPenetrationsTherearevariouscontainment(drywellandwetwell)electricalpenetrationassemblies.Mostarelocatedatnearlythesameelevationandinfourgroups aroundthedrywellperipheryapproximately90oapart.FourassembliesareusedsolelyfortheCRDpositioncables,fourforneutronmonitoringcables,two for4160Vacpowertotherecirculationpumps,oneformiscellaneousthermocouplesandotherlowlevelsignalcircuits,oneforlowlevelsignalcircuits,andthreeformiscellaneouspowerandcontrol.Apparatusordevicesinsidethedrywell,thewiringtowhichrequiresseparation,includeanumberofneutron monitoringcablesassociatedwiththeRPS,severalvalvepositionswitches whichserveasscramsensorsfortheRPS,safeguardcablesrelatedtotheRCIC,RHRandCoreSpraySystems.Althoughonegroupofpenetrationassembliesisseparatedfromtheothersontheexteriorofthedrywellbyconcretewalls,nobarriersexistinsidethedrywell.Separationisprovidedbyvirtueofthespacingofgroupswhichareabout40feet apart. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage7of10I/arbTheneutronmonitoringcablesaredividedintofourchannels.Eachchannelisroutedthroughaseparatepenetrationassembly.Threeoftheseassembliescontainonlyneutronmonitoringcables.Thefourthalsocontainsfourshieldedcablesusedforvibrationdetectorsignalsofextremelylowenergylevel.The fourassembliesarearrangedinpairs,eachpairondiametricallyoppositesides ofthedrywell.Thecablestoandfromeachofthesepenetrations,beinginthe RPSareinstalledincompletelyenclosedracewaysystemsaspreviouslydescribed.Thescramsensorcablesarealsoinfourchannelswhichareroutedthroughtwodiametricallyoppositepenetrationassemblies.Eachassemblycontainstwo groupsofconductorswhichareusedonlyfortheRPScircuits.Eachgroupisseparatedfromtheothergroupandfromotherconductorsinthepenetration assemblybycompleteenclosureinmetallicconduitinsideandoutsidethepenetrationassembly.Theotherconductorsinthesetwopenetration assembliesareusedformiscellaneouspowerandcontrolapplications,including someofthetwo-channelsafeguardservices.Redundantchannelsutilizethediametricallyoppositepenetrationassemblies.8.8.6RacewaysRacewaysofseveraltypesareusedthroughouttheplantfortheroutingofpower,control,andinstrumentcables.Cabletrayisusedforroutingthemain concentrationsofcablesaroundtheplant.Cabletraysaresteelandare manufacturedandtestedinaccordancewithNEMACableTrayStandardsVE-1 (Reference49).Thetraysaredesignedtowithstanda100lb/ftloadingwithdeflectionnotexceeding0.25inchforan8footspan.Traysupportsarespaced8footorcloserandarepredominantlyconstructedofunistrutchannels,inserts andfittings.Traysforpowerandcontrolgenerallyareoftheladdertype.Covers areprovidedwherecablesmaybesubjecttomechanicaldamageorinareas whereuncoveredtraysmighttendtocollectdebris.Traysforinstrumentationaresolidbottom,andprovidedwithcoverstoreduceelectricalnoisepickup. | |||
Solidbottomtrayswithcoversarealsousedforpowerandcontrolcablesin congestedareaswheretheminimumspacingforopentrayscannotbeobtained. | |||
Wheretraysinarunarestacked,theverticalspacingisgenerally1footor greater.Exceptforthesafeguardtrayspreviouslydiscussed,theminimumhorizontalseparationisdeterminedbyaccessibilityrequirementsduringandafterconstruction.Galvanizedrigidsteelconduitisusedforcablesofalltypesroutedfromtraystoapparatusandlocaldevices,andforotherexposedruns.Rigidsteelconduitisalsousedformanyembeddedandundergroundruns.Thinwallconduitisused onlyforlightingandcommunicationscircuits.Shortrunsofflexible,liquid-tight conduitareusedwherevibrationmaybeencounteredortofacilitateremovaloftheconnecteddevice.Fittingsandboxesaremadeofsteel.Someofthe4inchandlargerrunsembeddedinconcretearemadewithplasticconduit.Someundergroundrunsaredirectlyburiedintheearthandareprotectedbyaheavy woodplank.Galvanizedsteelgutterisusedinsomeapplications. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage8of10I/arbWherepractical,conduitfillisheldwithinthepercentagerecommendedbytheNationalElectricalCode(NEC).Trayfillistrackedandcontrolledtolimitexcessiveconcentrationsofheatproducingcablesandexcessivesidewallpressureexertedonindividualcablesbyothercables.8.8.7CablesCablesarequalifiedfortheirspecificapplications.Examplesofcabletypesusedforvariousservicesareasfollows:13.8KV15KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.4160Vac5KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.600Vac(orOzoneresistantbutylrubberinsulation,neoprenejacket,sizeless)Powerasrequired,No.10AWGminimum.Somepowercablesinside Cablethedrywellusecross-linkedpolyethyleneinsulation.CableswithEPRinsulation,hypalonjacketarealsoused.Feeder cablestoMCC115andMCC124arequalifiedforthespecific undergroundinstallationinvolvedControlMostlymulti-conductorNo.14AWGwith20milsPEinsulation Cableand10milsPVCjacketonthesingles,andPVCjacketoverall.SomeNo.12AWGandNo.10AWGcontrolcablesareused. | |||
SingleconductorcontrolcablewhereusedisNo.10AWGminimumsize.Controlcablesinsidethedrywellandinsomeotherapplicationsusecross-linkedpolyethyleneinsulationwith aneoprenejacket.SpecialAgreatnumberofspecialcablesforparticularapplicationsare Cableused.Followingaresomeofthemorecommontypes:1.CablesformiscellaneousinstrumentationandcomputerusagearePEinsulated,No.16AWG,braidortapeshield, PVCjacketed.Thermocoupleextensionleadsaresimilar.2.Neutronmonitorcablesarecoaxial,tripleshielded,orshieldedpairs,PEinsulation,shields,PVCjacketoverall.3.CRDpositioncablesinsidethedrywellaremulti-conductorNo.20AWG,cross-linkedpolyethylene,neoprenejacket.4.Specialmulti-conductorcontrolapplications,particularlywhereusedwithseparableconnectorsareNo.16toNo.20 AWG,PEorXLPEinsulatedsometimesshielded,PVCjacketoverall.Inselectingconductorsizes,properconsiderationisgiventotheambienttemperatureandtothetypesofracewaysthroughwhichthecableisrouted.Inmostareasoftheplantthedesignambientistakenas40oC(104F).Higherlocaltemperaturesincertainareasarefactoredinasrequired.Insidethedrywellthedesignambienttemperatureis66C(150F).01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage9of10I/arbForpowercablesinconduitsandtrays,thecablemanufacturer'srecommendations,relevantICEA(formerlyIPCEA)standardsorrelevantindustrystandardsareusedasaguideinselectingtheproperderatingfactor.TheICEAstandardstakesomecreditforadegreeofdiversityintheloadingof thecablesandthefactthatthereareanumberofcontrolcablesandidlepower cableswhichdonotproduceheat.Cableoverloadsarepreventedbytheproperselection,applicationandsettingofprotectiverelays,circuitbreakers,seriestripelementsmotoroverloadheaters,andfuses.Cablesareprotectedagainstdamagefromshortcircuitsbyselectingaconductorwhichwillcarrytheavailablefaultcurrentforthelengthoftimerequiredfortheprotectivedevicetoclearthefault,withoutexceedingthe manufacturer'smaximumshortcircuittemperatureratingfortheconductorinsulation.8.8.8SpecialConsiderationsa.Thenon-safeguardcableinstallationsdonotcompromisethoseprovidedfortheprotectivefunctions.TheRPScablesareintheirownracewaysystemandarenotexposedtocablesofothersystems.Althoughsafeguardcablesandnon-safeguardcablesmayberoutedthroughthesameraceways,thechannelseparationprovidedforthesafeguardcables preventsaccidentsfrominvolvingmorethanoneoftheredundant channels.Thepreviouslydescribedconservativeracewayloading,cable derating,andprotectionagainstelectricalfaults,inconjunctionwiththeassociatedcircuitsanalysis,eliminatesthepossibilityofthesafeguardcablesdescribedinreference6frombeinginvolvedwithfaultsinthenon-vitalcircuits.b.Inconjunctionwiththecomputerprocessedracewayandcircuitschedules,appropriateracewaysandcablesintheplantareassignedanumber.Racewayandcablenumbersincludeanodd-evendesignation,whichgenerallycorrespondstothesystemwithwhichtheyarerelated. | |||
Eachracewayismarkedwithitsidentificationnumber.Thecablenumber isattachedtoeachendofeachcable.Duringthedesignphaseand duringconstructionthecomputerprocessedcircuitandracewayschedulesaretheprimarymeansforcontrollingtheinstallationofRPSandsafeguardcablessothattherequiredchannelseparationisachieved. | |||
Elementarydiagramsorschematicdiagramsforcircuitswhichrequireseparationcarryanotationthatmandatoryseparationoftheredundantfunctionsistobeprovided.Tofacilitatetheroutingseparation,wherepossible,advantageistakenoftheracewaynumberingsystemfor odd-evencables. | |||
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage10of10I/arbc.ControlovertheinstallationofcablestoensurethatthedesignrequirementsaremetisprovidedbytheQualityAssuranceProgram.RPSandsafeguardcablesareincludedinthisprogram.Becausesafeguardcablesarenotnecessarilyseparatedfromnon-safeguardcables,racewayscontainingreactorprotection,safeguards,orassociatednon-safeguardscablesareincludedundertheQualityAssurance Program.TheQualityAssuranceProgramassuresthatthecableinstallationshavebeenmadeproperlyandthattheycomplywiththedesignwithrespecttocabletype,identification,routingandconnections, andthattheracewaysareofthecorrecttypesandareproperlyinstalled, andidentified. | |||
SECTION 88.98.9.1 | |||
SECTION 88.10 | |||
SECTION 88.118.11.1 | |||
8.11.2 | |||
8.11.3 | |||
SECTION 88.12 | |||
SECTION 88.13 | |||
Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of6SECTION8PLANTELECTRICALSYSTEMSI/arbFIGURES Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of6I/arbFigure8.3-2LPCISwingBusDegradedPowerTransferSchemeLPCISwingBusDegradedPowerTransferSchemeActuationofanyoftheserelayswillcausetrippingrelay(94P)toopenACB52-3300andcloseACB52-4300.ThistransfersthepowersupplytotheswingbusfromDivisionItoDivsionII.FromDiv.IMCC133A(480V)LPCIInjectionValvesLoopAMCC133BLoadCenter103CoreSprayInjection Valves27-33B27-33A59N-3381-3327-33480/120P.T.ACB52-307(N.C.)ACB52-3300(N.C.)94P(480V)FromDiv.IILoadCenter104ACB52-407(N.C.)ACB52-4300(N.O.)MCC143BMCC143ALPCIInjectionValves LoopBCoreSprayInjectionValvesRelayDesignations27-33A:LossofVoltagewith#11EDGOutputBreakerClosed27-33B:DegradedVoltagewith#11EDGOutputBreakerClosed 59N-33:OverVoltagewith#11EDGOutputBreakerClosed81-33:OutofFrequencywith#11EDGOutputBreakerClosed27-33:LossofNormalVoltage 94P:TrippingRelayTRIPCLOSE Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of6I/arbFigure8.4-1DieselGenerationSystemOneLineDiagramToAuxiliaryTransformer(2R) orReserveTransformer(1R)ToReserveAuxiliaryPower Transformer(1AR)No.11DieselGenerator 3125KVA 4.16KV0.80PFNo.12DieselGenerator3125KVA 4.16KV0.80PFToReserveAuxiliaryPower Transformer(1AR)ToAuxiliary Transformer(2R) orReserveTransformer(1R)LC109SPAREBREAKERCIRC.WATERPUMP1250HPLC107LC101TURBINEAUXOILPUMP250HPLC103RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HPCORESPRAYPUMP800HPRHRPUMP600HP*RHRPUMP600HP*INTERTIEFEEDERLC104RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HP CORESPRAYPUMP800HPRHRPUMP600HP* | |||
RHRPUMP600HP*INTERTIEFEEDERLC102LC108CIRCWATERPUMP1250HPSPAREBREAKERSPAREBREAKERBUSNo.13BUSNo.15BUSNo.16BUSNo.14*NOTE:MONTICELLO'SINVENTORYINCLUDESBOTH600AND700HPMOTORSTHATMAYBEUSEDONANYOFTHEFOURRHRPUMPS.01351161 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of6I/arbFigure8.5-4#17-250VdcDistributionPanel(D71)01298950 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of6I/arbFigure8.7-1InstrumentACandUninterruptibleACDistributionSystemSingleLineDiagram120VAC1120VAC1 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of6I/arbFigure8.7-2Y91UninterruptibleACDistributionSystemSingleLineDiagram13DGC40PDS1Y96C40PDS2FILTERNY96XY96BXY96ANPDS96COMPUTEREQUIPMENT3RDFLOORH&VRM2NDADDITIONOLDH&VRM3RDFLOOREASTELECTRICAL EQUIPMENTRMNPDS1ANPDS1NPDS2ANPDS2XPDS2XPDS1Y94480VACY93MAINTENANCEBYPASSSWITCHY90120/208VACY91UPSD71#17BATTERY 250VDC52-70452-80452-80152-701LC108LC10752-71052-711COMPUTERRMXY90}} | |||
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| Issue date: | 01/26/2016 |
| From: | Northern States Power Co, Xcel Energy |
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Text
SECTION 8
Revision 22USAR 8.1MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 1SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.1SummaryThe plant electrical power system is designed to provide a diversity of dependablepower sources which are physically isolated so that any one failure affecting one source of supply will not propagate to alternate sources. The plant auxiliaryelectrical power systems are designed to provide electrical and physicalindependence and adequate power supplies for startup, operation, shutdown, and for other plant requirements which are important to safety.In the event of a loss or degradation of all off-site power sources, auxiliary powerwill be supplied from diesel generators located on the site. These power sources are physically independent from any normal power system. Each power source, up to the point of its connection to the auxiliary power bus, is capable of completeand rapid electrical isolation from any other sources. Loads important to plantsafety are split and diversified between switchgear sections and means are provided for rapid location and isolation of system faults. Plant batteries are provided as a reliable source of control power for specific engineered safeguards and other functions required when AC power is not available.FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.01Doc Type:Admin Initials:Date:9703 Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of2SECTION8PLANTELECTRICALSYSTEMSI/eak8.2TransmissionSystem8.2.1NetworkInterconnectionsOutputoftheMonticelloNuclearGeneratingPlantisdeliveredtoa345/230/115/13.8KVswitchyardlocatedontheplantsite.DrawingNH-178635, Section15,showstheonelinediagramfortheMonticelloplantandits connectionstothetransmissionsystem.The345KVportionoftheswitchyardhaspositionsforconnectingthegeneratoroutput,threetransmissionlines,a345-230-13.8KVautotransformera345-13.8KVtransformer,a345-34.5KVtransformer,anda345-115-13.8KV autotransformer.The345KVbusandcircuitbreakerarrangementisa breaker-and-one-halfsystem.One345KVtransmissionlineisroutedtoconnect intothe345KVlooparoundtheTwinCitiesMetropolitanAreaattheElmCreekSubstation.Thesecondlineconnectstothe345KVtransmissionsystematSherburneCountySubstation.Thethirdlineconnectstothe345KVQuarry Substation.The230KVportionoftheswitchyardisprovidedtoestablishaninterconnectionwiththetransmissionsystemoftheGreatRiverEnergy.Anautotransformerconnectsthe345KVand230KVbusses.The115KVportionoftheswitchyardisconnectedtothe345KVbusthroughanautotransformer.The115KVbusisarrangedinaringbusconfiguration.In additiontotheautotransformerconnectiontothe115KVbus,therearethree transmissionlineconnectionsandaconnectiontoaplantauxiliarytransformer.Oneofthethreetransmissionlinesconnectsintothe115KVtransmission systematLakePulaskiSubstationandatDickinsonSubstation,anotheratHassanSubstation,andthethird115KVlineconnectstotheLibertysubstation.The13.8KVportionoftheswitchyardisprovidedtoestablishreliablepowersourcestovariousplantequipment.Theseincludetheplantauxiliaryreservetransformer(1AR);dischargestructuretransformers(X7,X8);coolingtowerfan transformers(X50,X60,X70,X80);transformerXP91whichpowersthe hydrogenwaterchemistrycryogenicsystempanelandanalternatefeed (throughtransformer6)tothetrainingcenter.
Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of2I/eakThesix(345KVand115KV)transmissionlineconnectionstotheswitchyardareallconnectedintotheXcelEnergyinterconnectedtransmissiongrid.Theirpointsofconnectiontothegridarearrangedbyroutesandintra-right-of-wayspacingtominimizemultiplelineoutageswhileperformingtherequirementof deliveringpowertolocationswhichbestsatisfysystemgrowthneeds.The345KVand115KVlines,aswellasthelinestowhichtheyinterconnect,are designedandbuilttoexceedtherequirementsoftheNationalElectricSafetyCodeforheavyloadingdistricts,GradeBconstruction(Reference41).Lightningperformancedesignofthetransmissionlinesisbasedonlessthanoneoutage per100milesperyear.ThesixXcelEnergytransmissionlinesleavetheMonticellosubstationthroughfourseparaterights-of-way:SherburneCountylinecorridor;Libertylinecorridor; Quarrycorridor;andacommoncorridorfortheElmCreek,Dickinson-LakePulaski,andHassanlines.Theserights-of-wayareconsideredindependentastheyaregreaterthan1/4mileapartatadistanceof1milefromtheplant.Threetransformersareprovidedtosupplytheplantwithoffsitepowerfromthesubstation.Allthreesourcescanindependentlyprovideadequatepowerforthe plant'ssafety-relatedloads.Thesetransformersandtheirinterconnectionsto thesubstationareasfollows:Theprimarystationauxiliarytransformer,2R,isfedfrom345KVBusNo.1via345KVto34.5KVtransformer2RS,andundergroundcablingfromthesubstationtotheareanorthwestoftheturbinebuildingwhere2Rtransformer islocated.2Rtransformerisofadequatesizetoprovidetheplant'sfull auxiliaryloadrequirements.Thereservetransformer,1R,isfedfromthe115KVsubstationviaanoverheadlinefromthesubstationtotheareanorthwestoftheturbinebuildingwhere1Rtransformerislocated.1Rtransformerisofadequatesizetoprovidetheplant'sfullauxiliaryloadrequirements.Thereserveauxiliarytransformer,1AR,islocatedsouthwestofthereactorbuildingandmaybefedfromtwoseparate13.8KVsourcesinthe substation.Onemethodofsupplying1ARtransformerisfromthetertiary windingof#10transformer,theauto-transformerwhichinterconnectsthe345KVand115KVsystems.Powerisroutedfromthetertiarywindingof10transformerto1ARviacircuitbreaker1N2andundergroundcablingfromthe substationto1ARtransformer.Thealternatemethodoffeeding1ARisfrom the345KVsubstationvia345KVto13.8KVtransformer1ARS,circuit breaker1N6,andundergroundcablingfromthesubstationto1AR.Circuitbreakers1N2and1N6areinterlockedtopreventhavingbothbreakerssimultaneouslyintheclosedposition.1ARtransformerissizedtoprovide onlytheplant'sessential4160Vacbusesandconnectedloads.01405303 SECTION 88.38.3.1
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bus tie breaker for Load Centers 101 and 102 is physically located in LC-102
SECTION 88.48.4.1
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NOTE 1:NOTE 2:NOTE 3:NOTE 4:NOTE 5:NOTE 6:NOTE 7:NOTE 8:
NOTE 9:NOTE 10:
NOTE 11:NOTE 12:NOTE 13:NOTE 14:
SECTION 88.5
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Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 3SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.6Reactor Protection System Power Supplies8.6.1Design BasisTwo motor generator sets provide AC power for operation of the ReactorProtection System. These sets are powered from 480 Vac buses and are used to supply power to the scram logic channels as well as neutron and radiationmonitoring systems. These sets are termed interruptible power supplies sinceloss of AC power to them causes a delayed loss of output as the inertial energy of the flywheel is converted to power for the connected loads.These systems are designed to provide a continued output of 120 Vac powerthat is free of transients and is extremely reliable. Switching transients andmomentary losses of input power will not cause substantial changes in outputvoltage or frequency.8.6.2DescriptionInterruptible Power SuppliesThe normal power supply will consist of two motor generator sets, eachconsisting of a three-phase induction motor driving a 120 Vac single-phasegenerator with flywheel. The flywheel provides energy to maintain generator output during momentary system faults or transients which do not otherwise impair reactor operation. One side of each generator output circuit will be grounded. The generator has a brushless exciter with an SCR voltage regulator.Voltage regulation is maintained within +/-2%. The voltage level is adjustableapproximately+/-10%. Each motor is fed from a separate 480 Vac bus. A powersupply from an essential source is not required for these units because thefail-safe design of the plant protection system results in a scram prior to essential bus transfer to the diesel generators.An alternate power source is provided to permit servicing of either motorgenerator set. Manual circuit breakers with a mechanical interlock prevent paralleling a motor generator set and the alternate source while transferring the load between them.The loads for these power supplies are indicated in Drawing NE-36771-4,Section 15. The principal loads on the system are magnetic contactors, AC type solenoid operated air valves, and electronic equipment for radiation and neutron monitoring.Electrical Protection Assemblies provide overvoltage, undervoltage, andunder-frequency protection to components served by these power supplies(Reference 24).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.06Doc Type:Admin Initials:Date:9703 Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 3I/mab8.6.2.1GeneralThe flywheel MG sets are provided to supply continuing AC power availabilityand to provide transient-free power. The use of flywheels sustains energydelivery for short periods of time when input energy is not available. The use of MG sets provide complete isolation from normal transients since there is no opportunity for inductive coupling as there would be with regulating transformers.8.6.2.2Loss of OutputInterruptible Power Supply BusesAs with the other components of the reactor protection systems, a componentfailure can be tolerated without loss of protection and without causing a scram.
This situation is also true with the interruptible AC power supplies. Loss ofoutput of one of the power supplies will result in the loss of functions of all unitsconnected to this bus leaving them in a tripped condition. Thus, if any one of the functions on the second protection bus should trip, a scram would result.
This would occur regardless of whether the trip was spurious or warranted.
Loss of voltage on either of the buses is annunciated in the control room bytripping of all auto scram parameters, providing opportunity for repair withoutshutting the reactor down.Electrical Protection Assemblies monitor the electric power in each of the threesources of power (RPS M-G sets A and B, and the alternate source) to the RPS. Each assembly consists of two identical and redundant packages. Eachpackage includes a circuit breaker and a monitoring module. When abnormalelectric power is detected by either module, the respective circuit breaker will trip and disconnect the RPS from the abnormal power source.Each monitoring module will trip its associated breaker on overvoltage,undervoltage or under frequency. With the protective packages installed,abnormal output type failures (random or seismically caused) in either of thetwo RPS M-G sets (or the alternate supply) results in a trip of either one or both of the two Class 1E protective packages. This tripping interrupts the power to the affected RPS channel, thus producing a scram signal on that channel. A time delay is incorporated in the circuit to prevent spurious actuation. Up to afour-second time delay before circuit breaker tripping will not result in damageto components of the RPS or prevent the RPS from performing its safety functions.
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 3I/mab8.6.3Inspection and TestsThe above equipment is in service during normal plant operation. However, allthe equipment is inspected periodically to check for signs of malfunctioning.Sufficient alarms are provided to inform the operator of any abnormal operating condition.
Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 2SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.7Instrumentation and Control AC Power Supply Systems8.7.1Interruptible AC SystemThe interruptible portion of the instrumentation and control AC power systemprovides AC power to plant AC instrument loads. A single line diagram is shownin Figure 8.7-1.Distribution panel Y20 is supplied from the plant auxiliary system. An automatictransfer to an alternate source within the plant auxiliary system occurs if the original source fails. This panel supplies both critical and noncritical instrumentAC and control loads.8.7.2Uninterruptible AC System8.7.2.1Class 1E SystemThe system is composed of (2) Class IE inverters to provide a Division I and a Division II 120 Vac uninterruptible power source. The Division I inverter (Y71) issupplied by Division I 250 Vdc distribution panel D31 with an alternate AC source to the static switch from essential MCC 134 through a stepdown transformer.
The Division II inverter (Y81) is supplied by Division II 250 Vdc distribution panel D100 with an alternate AC source to the static switch from essential MCC 144through a stepdown transformer. Y71 supplies Class 1E distribution panel Y70and Non-IE distribution panel Y10. Y81 supplies Class IE distribution panel Y80 and Non-IE distribution panel Y30. A single line diagram is shown on Figure 8.7-1.During normal conditions, DC is supplied to the inverters by the Division I andDivision II 250 Vdc battery chargers with their respective batteries as a backup.On loss of DC input, various inverter malfunctions, or overloads, the static switch will transfer to the alternate AC source. An external manual bypass switch may be used to connect the load directly to the alternate source to allow maintenanceon the inverters.As required by Generic Letter 91-11, which documents the NRCs resolution ofGeneric Issues 48 and 49, plant procedures establish time limitations and surveillance requirements for vital instrument buses and associated inverters.
(References 29 and 30).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.07Doc Type:Admin Initials:Date:970305-415 Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 2I/mab8.7.2.2Non-Class 1E SystemThe system is composed of a single module UPS to provide an uninterruptiblepower source primarily to the VAX computer systems. The UPS (Y91) issupplied AC by Load Center 108 with an alternate 480 Vac source from Load Center 107. The 250 Vdc backup is provided to UPS Y91 by No. 17 250 Vdc battery through distribution panel D71. UPS Y91 supplies a 3-phase 480 Vac distribution panel Y94 and also 120/208 Vac distribution panels Y90, Y96,PDS1 and PDS2 through 480 - 120/208 Vac transformers. A single linediagram of the system is shown on Figure 8.7-2.During normal conditions, 480 Vac power is supplied to the rectifier/inverter unitby Load Center 108. On loss of 480 Vac input, the No. 17 battery will supply the power required by the inverter to the loads and on a UPS failure the staticswitch will transfer the load to the alternate source, LC 107.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of10SECTION8PLANTELECTRICALSYSTEMSI/arb8.8ElectricalDesignConsiderations8.8.1DivisionSeparationThedesignandinstallationofcablesandracewaysforthereactorprotectionandengineeredsafeguardsystemsprovidesprotectionandseparationofwiringfor redundantchannelsadequatetoachieveanindependenceoffunctionwhichis compatiblewiththedegreeofsystemandequipmentredundancyinvolved.Thespecificcablesandracewaysinthecategoryforwhichseparationisprovidedincludethoseforcircuitsinvolvedinthecontrol,protection,andsupplyofpowertothereactorprotectionandengineeredsafeguardssystems.Circuits relatedtothesesystems,butforwhichseparationisnotnecessarilyprovided, includecablesandracewaysforinstrumentationandalarmswhichhave informationsignificanceonly,andwhichdonotinvolveautomaticcontrolfunctionsofanykind.Furthermore,separationisnotnecessarilyprovidedforpowercircuitswheretheparticularsystemisfail-safeonlossofpower.Forthosecircuitswhichareinthecategoryrequiringseparation,controlwiring fromthesensorstothelogicdevicesandtothefinalcontrolledelement,and powerwiringfromthesource,throughthecontrollertotheloadapparatus,areroutedsothattheredundantchannelsarephysicallyseparatedbyspaceorbybarriers.Cablesforthereactorprotectionsystemareroutedinacompletelyenclosedmetallicracewaysystemcomposedofrigidsteelconduit,steelboxes, andfittings,steelguttersorcoveredsteeltrays.Thisracewaysystemcontains nocircuitsotherthanfortheprotectionsystem,andprovidescompleteseparationofredundantchannels.Cablesforengineeredsafeguardcircuitsare routedintraysand/orconduitswhichprovideadequateseparationofredundant channels.Controlapparatus,distributionequipment,andpowersourcesare alsoseparated.Thedieselgenerators,essential4160Vacand480Vac switchgear,480VacMCC's,andthestationbatteriesareinseparateareasisolatedbyconcretefloorsorwalls.Controlroompanelscontainingdevicesforredundantchannelsareprovidedwithsteelbarriersseparatingthechannelsor redundantsystemsareseparatedby3feetormore.Localpanelsprovide equivalentseparation.Theplantarrangementissuchthatintheturbine-generatorbuilding,whichhousestheessential4160Vacswitchgear,480Vacloadcenters,and480VacMCCswiththeexceptionofMCCs134and144,theapparatusandconnecting racewaysassociatedwitheachredundantchannelarelocatedondifferentlevels separatedbyareinforcedconcretefloor.Thetwodiesel-generatorsarelocatedinseparateroomsabuttingtheturbine-generatorbuilding.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of10I/arbConnectionsfromthediesel-generators,andrelatedequipment,totheapparatusorracewaysintheturbine-generatorbuildingareinrigidsteelconduitswhicharealsoseparatedfromtheredundantchannelbytheconcretefloor.Wheretheracewaysapproachthecablespreadingroom,thetraysofoppositechannels,ofnecessity,approacheachothermorecloselyand separationhereisprovidedbywallsandbarriers.MCCs134and144arelocatedondifferentfloorsoftheEFTbuildingandareseparatedbyaconcretefloor.Insidethecablespreadingroomseparationisprovidedbyhorizontalorverticalspacingoftheracewaysand/orbytheuseofmetallicbarriers.Inthereactorbuildingwhereracewaysapproachthecablespreadingroomaconcreteblockwallseparatestraysoftheoppositedivision.Inthebalanceofthereactorbuilding,separationisprovidedbyspace,barriers,structures,or combinationsthereof.Exceptforthereactorprotectionsystemwhichhasitsownracewaysystem,thesafeguardcablesarenotseparatedfromnon-safeguardcables.Separationis onlyprovidedbetweencablesinonechannelfromtheirredundantcounterpartsintheotherchannel.TofacilitateidentificationofsafeguardchannelstheredundantsystemsareclassifiedasDivisionsIandII.ApparatusrelatedtothesedivisionsaregenerallyidentifiedAandBoroddandevenrespectively.
Theodd-evendesignationappliesparticularlytothepowersources,switchgear, anddistributionapparatusrelatedtotheredundantpowersystems.Racewaysarealsonumberedodd-even.Generallytheoddracewaysareroutedtotheareasoccupiedbytheodd,DivisionIorAequipment,andtheevenracewaysto theeven,DivisionIIorBequipment.Theseparationoftheoddandeven racewaysinmostcases,isequaltoorbetterthantheminimumdescribed previously.Incongestedareassuchasthecablespreadingroomsomeoddandeventraysareofnecessitymuchcloserthantheminimumallowancebythecriteria.Where thisoccursthesetraysareusedonlyfornon-safeguardcables.Thesafeguard cablesareonlyroutedintrayswhereadequateseparationexists.AlthoughmostDivisionIsafeguardcablesareroutedinoddnumberedracewaysandDivisionIIcablesinevenraceways,thereareoccasionswherethisisnot true.TherearealsopossiblesituationswhereDivisionIandIIcablesoccupy thesameraceway.Thiswouldoccurrarelyandwouldonlyinvolvecablesof unrelatedsystemsandnottheredundantcounterpartsrelatedtothesameprotectivefunction.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of10I/arb8.8.2OriginalSeparationCriteriaForThePrimaryContainmentIsolationSystem(PCIS)andtheEngineeredSafeguardsSystemsTheoriginalseparationrequirementsforthePCISandEngineeredSafeguardsSystemsareshownbelow.Separationrequirementsformissileandfirehazards arestatedintermsofdistance.Theseparationstandardallowsforcloser spacingwheresuitablefireandmissilebarriersexist.a.MechanicalDamage(MissileZone)Thesearezonesofpotentialmissiledamageinthevicinityoflarge rotatingapparatusorhighpressurepiping.Inthesezonesracewaysare separatedbyatleast20feetorbya6inchthickreinforcedconcretewall orfloor.Anexceptiontothisrequirementisinsidethedrywellwhere limitedspace,insomecases,preventsattainmentoftheminimum.Wherethisoccurscareistakentolocatetheredundantracewayssothatasinglemissilewillnotdamagebothchannels.b.FireHazardZoneTypeI.Theseareareaswhereoilorothercombustiblesarepresentin largequantitieswhichcouldsupportadamagingfire.Theroutingofracewaysthroughthesezonesisavoidedwhereverpracticable.Whereitisnecessarytorouteracewaysthroughsuchareasonlythoseforone divisionoftheengineeredsafeguardcablesarelocatedtherein.No cablesareroutedthroughtheturbineoilstorageroom.TypeII.Theseareareaswheretheonlysourceoffireisofanelectricalnatureandcombustiblematerialsconsistprimarilyofelectricalinsulation.Intheseareastraysoftheoppositedivisionareseparatedbyatleast3feethorizontallyor5feetverticallyforstackedtrays.Whena3foot horizontalseparationisnotattainablefireresistantbarriersareprovided betweenthetwotrays.Wheretraysarestackedandmeetthe5footseparationrequirement,thetoptrayisalsoprovidedwithasolidsteelbottomandthebottomtraywithasolidsteelcover.Whentraysof oppositedivisionscrosstheseparationmaybereducedto18inches providedthetraytopandbottomcoversextend5feetormoreeachside ofthecrossing.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of10I/arbc.CableSpreadingRoomThisistheroombelowthemaincontrolroomandcontainscabletrays,conduits,gutters,andboxesusedtoroutecablespassingthroughtheroom,andcablesroutedtothecontrolroomboardsabove.Thecable spreadingroomalsohousesanumberofcontrolorrelaypanelsand instrumentACdistributionpanels.Thecriteriafortrayseparationof3foot horizontally,5footvertically,18inchesatcrossingswithtraybottomsandtopscoveredaspreviouslydescribed,isappliedherealso.Wheretraysofoppositedivisionapproachmorecloselythan3foothorizontally,afire resistantbarrierbetweenthetraysisprovided.Cablesleavingtraysof oppositedivisionsandwhichapproacheachothermorecloselythan3 footarebothruninseparatesteelconduitsorenclosedgutters.d.ControlRoomPanelsNosinglecontrolroompanel(orlocalpanelorinstrumentrack)includes wiringforbothDivisionIandIIunlessthefollowingseparation requirementsaremet.Iftwopanelscontainingcircuitsofdifferentdivisionsarelessthan3feetapart,afirebarriershallbebetweenthetwopanels.Panelendsclosedinsteelendplatesareacceptableaslongasthedivisionalterminalboards andwirewaysareoneinchfromtheplate.Floortopanelbarriersare providedbetweenadjacentpanelshavingclosedends.Apanelmaycontainwiringandcomponentsoftwoengineeredsafeguardssystemsredundanttoeachotherprovidedthatthepanelissubdividedbymeansofafirebarrier.Nocableterminalblocksorother componentsshouldbelocatedlessthanoneinchfromsuchabarrier.
Penetrationofseparationbarrierswithinasubdividedpanelispermitted providedthatsuchpenetrationsaresealedorotherwiseratedsothatan electricalfirecouldnotreasonablypropagatefromonesectiontotheotheranddestroytheprotectivefunction.Incaseswherecircuitsandcomponentssuchasmanualswitches,indicatinglights,andannunciatorsarenotvitaltotheautomaticoperation ofredundantsafetysystems,thesecircuitsandcomponentsmaybe groupedtogetheronthesamecontrolroompanel.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of10I/arb8.8.3FunctionalSeparationInadditiontoprovidingchannelseparationasdescribedabove,theracewaysystemprovidesseparationbyfunctionasfollows:1.MediumVoltagePower13.8KVand4160Vacpowercablesareroutedinconduitsortraysseparatefromthoseforcablesofotherfunctions.2.LowVoltagePowerandControlThisclassificationincludescableswithinsulationratedat600Vacusedfor powerandcontrolcircuitsoperatedat480Vacand120Vacandat125Vdc and250Vdc.Powerandcontrolcablesarenotseparatedfromeachother.Racewaysconsistofladdertypetraysandrigidsteelconduit.3.SignalandInstrumentationCablesofthiscategoryareusedincircuitswhichoperateatverylow energylevelsandwhichmaybenoisesensitivebutwhicharenotnoiseproducers.Racewaysareselectedtominimizenoisepickupandconsistof solidbottomsteeltrayswithsolidcoversorrigidsteelconduit.The instrumentationcablesarenotroutedinthesameracewaysaspowerand controlcables.8.8.4EquipmentIdentificationandConfigurationManagementEquipment,includinglocallymounteddevices,whicharepartofengineered safeguardsystems,isprominentlymarkedwithnameplatesorequivalentmeanswhichuniquelyidentifythemasrequiredbytheplantlabelingandequipmentnumberingprograms.Conduits,cabletrays,boxes,andcablesexceptthosethatarepartoflighting,receptacle,communicationandcomputersystemsareassignedandmarkedwithauniqueidentificationnumber.Thisnumberisgenerallyusedon appropriatedrawings,schedules,listings,andconstructionrecordsandcontrols.Cablesaremarkedattheirends.Theracewayandcablenumberingsystemincorporatesanodd-evensignificancetoaidthedesignerinprovidingtheproperseparationofcablesinredundantsafeguardsystems.Strictadministrativecontrolscombinedwiththeproperusageofthedesigndrawings,schedules,andlistingsandtheidentificationmarkingofequipment, raceways,andcablesfacilitatesafetyduringplantoperationandmaintenance.Followingaredescribedanddiscussedtheprincipaldesigndocumentswhichprovidetheinformationnecessarytotheimplementationoftheadministrative controls.a.ConduitandTrayDrawings-Thesedrawingsidentifyandshowthephysicallocationofelectricalraceways,equipmentanddevicestowhichelectricalconnectionsaremade.01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of10I/arbb.Schematic(Elementary)Diagrams-Thesedrawings,inadditiontodefiningcircuitfunction,identifycaseswheremandatoryseparationofsafeguardcablesisrequiredandusually,bymeansoftheodd-evenschemenumber,indicatethesafeguardsdivisionofthesystemtowhicheachcableisrelated.CircuitScheduleThisscheduleincludesforeachcable,thecablenumber,schemenumber,cabletype,andadetailedroutingthroughracewaysfromorigintodestination.RacewaySchedule Thisscheduleincludesforeachraceway,theracewaynumber,type,size,percentfill,andalistingofcablesroutedtherein.ConnectionDiagramsThesedrawingsshowexternalconnectionstomajorapparatusandmostlocaldevices.Thecablenumbers,wirenumbers,andterminalsareshownonthesedrawings.CableListing-SchemeNumberSequenceThecableschedulemaybesortedandgroupedinschemenumbersequence.Referencetothisdocumentandtherelatedschematic(elementary)diagrampermitstheidentificationofcablesassociatedwithaparticularsystem.Further,thislistingmaybeusedtoidentifysafeguardcablesandtheirsafeguarddivision.8.8.5ElectricalPenetrationsTherearevariouscontainment(drywellandwetwell)electricalpenetrationassemblies.Mostarelocatedatnearlythesameelevationandinfourgroups aroundthedrywellperipheryapproximately90oapart.FourassembliesareusedsolelyfortheCRDpositioncables,fourforneutronmonitoringcables,two for4160Vacpowertotherecirculationpumps,oneformiscellaneousthermocouplesandotherlowlevelsignalcircuits,oneforlowlevelsignalcircuits,andthreeformiscellaneouspowerandcontrol.Apparatusordevicesinsidethedrywell,thewiringtowhichrequiresseparation,includeanumberofneutron monitoringcablesassociatedwiththeRPS,severalvalvepositionswitches whichserveasscramsensorsfortheRPS,safeguardcablesrelatedtotheRCIC,RHRandCoreSpraySystems.Althoughonegroupofpenetrationassembliesisseparatedfromtheothersontheexteriorofthedrywellbyconcretewalls,nobarriersexistinsidethedrywell.Separationisprovidedbyvirtueofthespacingofgroupswhichareabout40feet apart.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage7of10I/arbTheneutronmonitoringcablesaredividedintofourchannels.Eachchannelisroutedthroughaseparatepenetrationassembly.Threeoftheseassembliescontainonlyneutronmonitoringcables.Thefourthalsocontainsfourshieldedcablesusedforvibrationdetectorsignalsofextremelylowenergylevel.The fourassembliesarearrangedinpairs,eachpairondiametricallyoppositesides ofthedrywell.Thecablestoandfromeachofthesepenetrations,beinginthe RPSareinstalledincompletelyenclosedracewaysystemsaspreviouslydescribed.Thescramsensorcablesarealsoinfourchannelswhichareroutedthroughtwodiametricallyoppositepenetrationassemblies.Eachassemblycontainstwo groupsofconductorswhichareusedonlyfortheRPScircuits.Eachgroupisseparatedfromtheothergroupandfromotherconductorsinthepenetration assemblybycompleteenclosureinmetallicconduitinsideandoutsidethepenetrationassembly.Theotherconductorsinthesetwopenetration assembliesareusedformiscellaneouspowerandcontrolapplications,including someofthetwo-channelsafeguardservices.Redundantchannelsutilizethediametricallyoppositepenetrationassemblies.8.8.6RacewaysRacewaysofseveraltypesareusedthroughouttheplantfortheroutingofpower,control,andinstrumentcables.Cabletrayisusedforroutingthemain concentrationsofcablesaroundtheplant.Cabletraysaresteelandare manufacturedandtestedinaccordancewithNEMACableTrayStandardsVE-1 (Reference49).Thetraysaredesignedtowithstanda100lb/ftloadingwithdeflectionnotexceeding0.25inchforan8footspan.Traysupportsarespaced8footorcloserandarepredominantlyconstructedofunistrutchannels,inserts andfittings.Traysforpowerandcontrolgenerallyareoftheladdertype.Covers areprovidedwherecablesmaybesubjecttomechanicaldamageorinareas whereuncoveredtraysmighttendtocollectdebris.Traysforinstrumentationaresolidbottom,andprovidedwithcoverstoreduceelectricalnoisepickup.
Solidbottomtrayswithcoversarealsousedforpowerandcontrolcablesin congestedareaswheretheminimumspacingforopentrayscannotbeobtained.
Wheretraysinarunarestacked,theverticalspacingisgenerally1footor greater.Exceptforthesafeguardtrayspreviouslydiscussed,theminimumhorizontalseparationisdeterminedbyaccessibilityrequirementsduringandafterconstruction.Galvanizedrigidsteelconduitisusedforcablesofalltypesroutedfromtraystoapparatusandlocaldevices,andforotherexposedruns.Rigidsteelconduitisalsousedformanyembeddedandundergroundruns.Thinwallconduitisused onlyforlightingandcommunicationscircuits.Shortrunsofflexible,liquid-tight conduitareusedwherevibrationmaybeencounteredortofacilitateremovaloftheconnecteddevice.Fittingsandboxesaremadeofsteel.Someofthe4inchandlargerrunsembeddedinconcretearemadewithplasticconduit.Someundergroundrunsaredirectlyburiedintheearthandareprotectedbyaheavy woodplank.Galvanizedsteelgutterisusedinsomeapplications.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage8of10I/arbWherepractical,conduitfillisheldwithinthepercentagerecommendedbytheNationalElectricalCode(NEC).Trayfillistrackedandcontrolledtolimitexcessiveconcentrationsofheatproducingcablesandexcessivesidewallpressureexertedonindividualcablesbyothercables.8.8.7CablesCablesarequalifiedfortheirspecificapplications.Examplesofcabletypesusedforvariousservicesareasfollows:13.8KV15KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.4160Vac5KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.600Vac(orOzoneresistantbutylrubberinsulation,neoprenejacket,sizeless)Powerasrequired,No.10AWGminimum.Somepowercablesinside Cablethedrywellusecross-linkedpolyethyleneinsulation.CableswithEPRinsulation,hypalonjacketarealsoused.Feeder cablestoMCC115andMCC124arequalifiedforthespecific undergroundinstallationinvolvedControlMostlymulti-conductorNo.14AWGwith20milsPEinsulation Cableand10milsPVCjacketonthesingles,andPVCjacketoverall.SomeNo.12AWGandNo.10AWGcontrolcablesareused.
SingleconductorcontrolcablewhereusedisNo.10AWGminimumsize.Controlcablesinsidethedrywellandinsomeotherapplicationsusecross-linkedpolyethyleneinsulationwith aneoprenejacket.SpecialAgreatnumberofspecialcablesforparticularapplicationsare Cableused.Followingaresomeofthemorecommontypes:1.CablesformiscellaneousinstrumentationandcomputerusagearePEinsulated,No.16AWG,braidortapeshield, PVCjacketed.Thermocoupleextensionleadsaresimilar.2.Neutronmonitorcablesarecoaxial,tripleshielded,orshieldedpairs,PEinsulation,shields,PVCjacketoverall.3.CRDpositioncablesinsidethedrywellaremulti-conductorNo.20AWG,cross-linkedpolyethylene,neoprenejacket.4.Specialmulti-conductorcontrolapplications,particularlywhereusedwithseparableconnectorsareNo.16toNo.20 AWG,PEorXLPEinsulatedsometimesshielded,PVCjacketoverall.Inselectingconductorsizes,properconsiderationisgiventotheambienttemperatureandtothetypesofracewaysthroughwhichthecableisrouted.Inmostareasoftheplantthedesignambientistakenas40oC(104F).Higherlocaltemperaturesincertainareasarefactoredinasrequired.Insidethedrywellthedesignambienttemperatureis66C(150F).01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage9of10I/arbForpowercablesinconduitsandtrays,thecablemanufacturer'srecommendations,relevantICEA(formerlyIPCEA)standardsorrelevantindustrystandardsareusedasaguideinselectingtheproperderatingfactor.TheICEAstandardstakesomecreditforadegreeofdiversityintheloadingof thecablesandthefactthatthereareanumberofcontrolcablesandidlepower cableswhichdonotproduceheat.Cableoverloadsarepreventedbytheproperselection,applicationandsettingofprotectiverelays,circuitbreakers,seriestripelementsmotoroverloadheaters,andfuses.Cablesareprotectedagainstdamagefromshortcircuitsbyselectingaconductorwhichwillcarrytheavailablefaultcurrentforthelengthoftimerequiredfortheprotectivedevicetoclearthefault,withoutexceedingthe manufacturer'smaximumshortcircuittemperatureratingfortheconductorinsulation.8.8.8SpecialConsiderationsa.Thenon-safeguardcableinstallationsdonotcompromisethoseprovidedfortheprotectivefunctions.TheRPScablesareintheirownracewaysystemandarenotexposedtocablesofothersystems.Althoughsafeguardcablesandnon-safeguardcablesmayberoutedthroughthesameraceways,thechannelseparationprovidedforthesafeguardcables preventsaccidentsfrominvolvingmorethanoneoftheredundant channels.Thepreviouslydescribedconservativeracewayloading,cable derating,andprotectionagainstelectricalfaults,inconjunctionwiththeassociatedcircuitsanalysis,eliminatesthepossibilityofthesafeguardcablesdescribedinreference6frombeinginvolvedwithfaultsinthenon-vitalcircuits.b.Inconjunctionwiththecomputerprocessedracewayandcircuitschedules,appropriateracewaysandcablesintheplantareassignedanumber.Racewayandcablenumbersincludeanodd-evendesignation,whichgenerallycorrespondstothesystemwithwhichtheyarerelated.
Eachracewayismarkedwithitsidentificationnumber.Thecablenumber isattachedtoeachendofeachcable.Duringthedesignphaseand duringconstructionthecomputerprocessedcircuitandracewayschedulesaretheprimarymeansforcontrollingtheinstallationofRPSandsafeguardcablessothattherequiredchannelseparationisachieved.
Elementarydiagramsorschematicdiagramsforcircuitswhichrequireseparationcarryanotationthatmandatoryseparationoftheredundantfunctionsistobeprovided.Tofacilitatetheroutingseparation,wherepossible,advantageistakenoftheracewaynumberingsystemfor odd-evencables.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage10of10I/arbc.ControlovertheinstallationofcablestoensurethatthedesignrequirementsaremetisprovidedbytheQualityAssuranceProgram.RPSandsafeguardcablesareincludedinthisprogram.Becausesafeguardcablesarenotnecessarilyseparatedfromnon-safeguardcables,racewayscontainingreactorprotection,safeguards,orassociatednon-safeguardscablesareincludedundertheQualityAssurance Program.TheQualityAssuranceProgramassuresthatthecableinstallationshavebeenmadeproperlyandthattheycomplywiththedesignwithrespecttocabletype,identification,routingandconnections, andthattheracewaysareofthecorrecttypesandareproperlyinstalled, andidentified.
SECTION 88.98.9.1
SECTION 88.10
SECTION 88.118.11.1
8.11.2
8.11.3
SECTION 88.12
SECTION 88.13
Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of6SECTION8PLANTELECTRICALSYSTEMSI/arbFIGURES Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of6I/arbFigure8.3-2LPCISwingBusDegradedPowerTransferSchemeLPCISwingBusDegradedPowerTransferSchemeActuationofanyoftheserelayswillcausetrippingrelay(94P)toopenACB52-3300andcloseACB52-4300.ThistransfersthepowersupplytotheswingbusfromDivisionItoDivsionII.FromDiv.IMCC133A(480V)LPCIInjectionValvesLoopAMCC133BLoadCenter103CoreSprayInjection Valves27-33B27-33A59N-3381-3327-33480/120P.T.ACB52-307(N.C.)ACB52-3300(N.C.)94P(480V)FromDiv.IILoadCenter104ACB52-407(N.C.)ACB52-4300(N.O.)MCC143BMCC143ALPCIInjectionValves LoopBCoreSprayInjectionValvesRelayDesignations27-33A:LossofVoltagewith#11EDGOutputBreakerClosed27-33B:DegradedVoltagewith#11EDGOutputBreakerClosed 59N-33:OverVoltagewith#11EDGOutputBreakerClosed81-33:OutofFrequencywith#11EDGOutputBreakerClosed27-33:LossofNormalVoltage 94P:TrippingRelayTRIPCLOSE Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of6I/arbFigure8.4-1DieselGenerationSystemOneLineDiagramToAuxiliaryTransformer(2R) orReserveTransformer(1R)ToReserveAuxiliaryPower Transformer(1AR)No.11DieselGenerator 3125KVA 4.16KV0.80PFNo.12DieselGenerator3125KVA 4.16KV0.80PFToReserveAuxiliaryPower Transformer(1AR)ToAuxiliary Transformer(2R) orReserveTransformer(1R)LC109SPAREBREAKERCIRC.WATERPUMP1250HPLC107LC101TURBINEAUXOILPUMP250HPLC103RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HPCORESPRAYPUMP800HPRHRPUMP600HP*RHRPUMP600HP*INTERTIEFEEDERLC104RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HP CORESPRAYPUMP800HPRHRPUMP600HP*
RHRPUMP600HP*INTERTIEFEEDERLC102LC108CIRCWATERPUMP1250HPSPAREBREAKERSPAREBREAKERBUSNo.13BUSNo.15BUSNo.16BUSNo.14*NOTE:MONTICELLO'SINVENTORYINCLUDESBOTH600AND700HPMOTORSTHATMAYBEUSEDONANYOFTHEFOURRHRPUMPS.01351161 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of6I/arbFigure8.5-4#17-250VdcDistributionPanel(D71)01298950 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of6I/arbFigure8.7-1InstrumentACandUninterruptibleACDistributionSystemSingleLineDiagram120VAC1120VAC1 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of6I/arbFigure8.7-2Y91UninterruptibleACDistributionSystemSingleLineDiagram13DGC40PDS1Y96C40PDS2FILTERNY96XY96BXY96ANPDS96COMPUTEREQUIPMENT3RDFLOORH&VRM2NDADDITIONOLDH&VRM3RDFLOOREASTELECTRICAL EQUIPMENTRMNPDS1ANPDS1NPDS2ANPDS2XPDS2XPDS1Y94480VACY93MAINTENANCEBYPASSSWITCHY90120/208VACY91UPSD71#17BATTERY 250VDC52-70452-80452-80152-701LC108LC10752-71052-711COMPUTERRMXY90 SECTION 8
Revision 22USAR 8.1MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 1SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.1SummaryThe plant electrical power system is designed to provide a diversity of dependablepower sources which are physically isolated so that any one failure affecting one source of supply will not propagate to alternate sources. The plant auxiliaryelectrical power systems are designed to provide electrical and physicalindependence and adequate power supplies for startup, operation, shutdown, and for other plant requirements which are important to safety.In the event of a loss or degradation of all off-site power sources, auxiliary powerwill be supplied from diesel generators located on the site. These power sources are physically independent from any normal power system. Each power source, up to the point of its connection to the auxiliary power bus, is capable of completeand rapid electrical isolation from any other sources. Loads important to plantsafety are split and diversified between switchgear sections and means are provided for rapid location and isolation of system faults. Plant batteries are provided as a reliable source of control power for specific engineered safeguards and other functions required when AC power is not available.FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.01Doc Type:Admin Initials:Date:9703 Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of2SECTION8PLANTELECTRICALSYSTEMSI/eak8.2TransmissionSystem8.2.1NetworkInterconnectionsOutputoftheMonticelloNuclearGeneratingPlantisdeliveredtoa345/230/115/13.8KVswitchyardlocatedontheplantsite.DrawingNH-178635, Section15,showstheonelinediagramfortheMonticelloplantandits connectionstothetransmissionsystem.The345KVportionoftheswitchyardhaspositionsforconnectingthegeneratoroutput,threetransmissionlines,a345-230-13.8KVautotransformera345-13.8KVtransformer,a345-34.5KVtransformer,anda345-115-13.8KV autotransformer.The345KVbusandcircuitbreakerarrangementisa breaker-and-one-halfsystem.One345KVtransmissionlineisroutedtoconnect intothe345KVlooparoundtheTwinCitiesMetropolitanAreaattheElmCreekSubstation.Thesecondlineconnectstothe345KVtransmissionsystematSherburneCountySubstation.Thethirdlineconnectstothe345KVQuarry Substation.The230KVportionoftheswitchyardisprovidedtoestablishaninterconnectionwiththetransmissionsystemoftheGreatRiverEnergy.Anautotransformerconnectsthe345KVand230KVbusses.The115KVportionoftheswitchyardisconnectedtothe345KVbusthroughanautotransformer.The115KVbusisarrangedinaringbusconfiguration.In additiontotheautotransformerconnectiontothe115KVbus,therearethree transmissionlineconnectionsandaconnectiontoaplantauxiliarytransformer.Oneofthethreetransmissionlinesconnectsintothe115KVtransmission systematLakePulaskiSubstationandatDickinsonSubstation,anotheratHassanSubstation,andthethird115KVlineconnectstotheLibertysubstation.The13.8KVportionoftheswitchyardisprovidedtoestablishreliablepowersourcestovariousplantequipment.Theseincludetheplantauxiliaryreservetransformer(1AR);dischargestructuretransformers(X7,X8);coolingtowerfan transformers(X50,X60,X70,X80);transformerXP91whichpowersthe hydrogenwaterchemistrycryogenicsystempanelandanalternatefeed (throughtransformer6)tothetrainingcenter.
Revision30USAR-08.02MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of2I/eakThesix(345KVand115KV)transmissionlineconnectionstotheswitchyardareallconnectedintotheXcelEnergyinterconnectedtransmissiongrid.Theirpointsofconnectiontothegridarearrangedbyroutesandintra-right-of-wayspacingtominimizemultiplelineoutageswhileperformingtherequirementof deliveringpowertolocationswhichbestsatisfysystemgrowthneeds.The345KVand115KVlines,aswellasthelinestowhichtheyinterconnect,are designedandbuilttoexceedtherequirementsoftheNationalElectricSafetyCodeforheavyloadingdistricts,GradeBconstruction(Reference41).Lightningperformancedesignofthetransmissionlinesisbasedonlessthanoneoutage per100milesperyear.ThesixXcelEnergytransmissionlinesleavetheMonticellosubstationthroughfourseparaterights-of-way:SherburneCountylinecorridor;Libertylinecorridor; Quarrycorridor;andacommoncorridorfortheElmCreek,Dickinson-LakePulaski,andHassanlines.Theserights-of-wayareconsideredindependentastheyaregreaterthan1/4mileapartatadistanceof1milefromtheplant.Threetransformersareprovidedtosupplytheplantwithoffsitepowerfromthesubstation.Allthreesourcescanindependentlyprovideadequatepowerforthe plant'ssafety-relatedloads.Thesetransformersandtheirinterconnectionsto thesubstationareasfollows:Theprimarystationauxiliarytransformer,2R,isfedfrom345KVBusNo.1via345KVto34.5KVtransformer2RS,andundergroundcablingfromthesubstationtotheareanorthwestoftheturbinebuildingwhere2Rtransformer islocated.2Rtransformerisofadequatesizetoprovidetheplant'sfull auxiliaryloadrequirements.Thereservetransformer,1R,isfedfromthe115KVsubstationviaanoverheadlinefromthesubstationtotheareanorthwestoftheturbinebuildingwhere1Rtransformerislocated.1Rtransformerisofadequatesizetoprovidetheplant'sfullauxiliaryloadrequirements.Thereserveauxiliarytransformer,1AR,islocatedsouthwestofthereactorbuildingandmaybefedfromtwoseparate13.8KVsourcesinthe substation.Onemethodofsupplying1ARtransformerisfromthetertiary windingof#10transformer,theauto-transformerwhichinterconnectsthe345KVand115KVsystems.Powerisroutedfromthetertiarywindingof10transformerto1ARviacircuitbreaker1N2andundergroundcablingfromthe substationto1ARtransformer.Thealternatemethodoffeeding1ARisfrom the345KVsubstationvia345KVto13.8KVtransformer1ARS,circuit breaker1N6,andundergroundcablingfromthesubstationto1AR.Circuitbreakers1N2and1N6areinterlockedtopreventhavingbothbreakerssimultaneouslyintheclosedposition.1ARtransformerissizedtoprovide onlytheplant'sessential4160Vacbusesandconnectedloads.01405303 SECTION 88.38.3.1
8.3.2
8.3.3
8.3.4
8.3.5
bus tie breaker for Load Centers 101 and 102 is physically located in LC-102
SECTION 88.48.4.1
8.4.2
NOTE 1:NOTE 2:NOTE 3:NOTE 4:NOTE 5:NOTE 6:NOTE 7:NOTE 8:
NOTE 9:NOTE 10:
NOTE 11:NOTE 12:NOTE 13:NOTE 14:
SECTION 88.5
8.5.1
8.5.2
8.5.3
8.5.4
8.5.5
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 3SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.6Reactor Protection System Power Supplies8.6.1Design BasisTwo motor generator sets provide AC power for operation of the ReactorProtection System. These sets are powered from 480 Vac buses and are used to supply power to the scram logic channels as well as neutron and radiationmonitoring systems. These sets are termed interruptible power supplies sinceloss of AC power to them causes a delayed loss of output as the inertial energy of the flywheel is converted to power for the connected loads.These systems are designed to provide a continued output of 120 Vac powerthat is free of transients and is extremely reliable. Switching transients andmomentary losses of input power will not cause substantial changes in outputvoltage or frequency.8.6.2DescriptionInterruptible Power SuppliesThe normal power supply will consist of two motor generator sets, eachconsisting of a three-phase induction motor driving a 120 Vac single-phasegenerator with flywheel. The flywheel provides energy to maintain generator output during momentary system faults or transients which do not otherwise impair reactor operation. One side of each generator output circuit will be grounded. The generator has a brushless exciter with an SCR voltage regulator.Voltage regulation is maintained within +/-2%. The voltage level is adjustableapproximately+/-10%. Each motor is fed from a separate 480 Vac bus. A powersupply from an essential source is not required for these units because thefail-safe design of the plant protection system results in a scram prior to essential bus transfer to the diesel generators.An alternate power source is provided to permit servicing of either motorgenerator set. Manual circuit breakers with a mechanical interlock prevent paralleling a motor generator set and the alternate source while transferring the load between them.The loads for these power supplies are indicated in Drawing NE-36771-4,Section 15. The principal loads on the system are magnetic contactors, AC type solenoid operated air valves, and electronic equipment for radiation and neutron monitoring.Electrical Protection Assemblies provide overvoltage, undervoltage, andunder-frequency protection to components served by these power supplies(Reference 24).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.06Doc Type:Admin Initials:Date:9703 Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 3I/mab8.6.2.1GeneralThe flywheel MG sets are provided to supply continuing AC power availabilityand to provide transient-free power. The use of flywheels sustains energydelivery for short periods of time when input energy is not available. The use of MG sets provide complete isolation from normal transients since there is no opportunity for inductive coupling as there would be with regulating transformers.8.6.2.2Loss of OutputInterruptible Power Supply BusesAs with the other components of the reactor protection systems, a componentfailure can be tolerated without loss of protection and without causing a scram.
This situation is also true with the interruptible AC power supplies. Loss ofoutput of one of the power supplies will result in the loss of functions of all unitsconnected to this bus leaving them in a tripped condition. Thus, if any one of the functions on the second protection bus should trip, a scram would result.
This would occur regardless of whether the trip was spurious or warranted.
Loss of voltage on either of the buses is annunciated in the control room bytripping of all auto scram parameters, providing opportunity for repair withoutshutting the reactor down.Electrical Protection Assemblies monitor the electric power in each of the threesources of power (RPS M-G sets A and B, and the alternate source) to the RPS. Each assembly consists of two identical and redundant packages. Eachpackage includes a circuit breaker and a monitoring module. When abnormalelectric power is detected by either module, the respective circuit breaker will trip and disconnect the RPS from the abnormal power source.Each monitoring module will trip its associated breaker on overvoltage,undervoltage or under frequency. With the protective packages installed,abnormal output type failures (random or seismically caused) in either of thetwo RPS M-G sets (or the alternate supply) results in a trip of either one or both of the two Class 1E protective packages. This tripping interrupts the power to the affected RPS channel, thus producing a scram signal on that channel. A time delay is incorporated in the circuit to prevent spurious actuation. Up to afour-second time delay before circuit breaker tripping will not result in damageto components of the RPS or prevent the RPS from performing its safety functions.
Revision 22USAR 8.6MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 3 of 3I/mab8.6.3Inspection and TestsThe above equipment is in service during normal plant operation. However, allthe equipment is inspected periodically to check for signs of malfunctioning.Sufficient alarms are provided to inform the operator of any abnormal operating condition.
Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 1 of 2SECTION 8PLANT ELECTRICAL SYSTEMSI/mab8.7Instrumentation and Control AC Power Supply Systems8.7.1Interruptible AC SystemThe interruptible portion of the instrumentation and control AC power systemprovides AC power to plant AC instrument loads. A single line diagram is shownin Figure 8.7-1.Distribution panel Y20 is supplied from the plant auxiliary system. An automatictransfer to an alternate source within the plant auxiliary system occurs if the original source fails. This panel supplies both critical and noncritical instrumentAC and control loads.8.7.2Uninterruptible AC System8.7.2.1Class 1E SystemThe system is composed of (2) Class IE inverters to provide a Division I and a Division II 120 Vac uninterruptible power source. The Division I inverter (Y71) issupplied by Division I 250 Vdc distribution panel D31 with an alternate AC source to the static switch from essential MCC 134 through a stepdown transformer.
The Division II inverter (Y81) is supplied by Division II 250 Vdc distribution panel D100 with an alternate AC source to the static switch from essential MCC 144through a stepdown transformer. Y71 supplies Class 1E distribution panel Y70and Non-IE distribution panel Y10. Y81 supplies Class IE distribution panel Y80 and Non-IE distribution panel Y30. A single line diagram is shown on Figure 8.7-1.During normal conditions, DC is supplied to the inverters by the Division I andDivision II 250 Vdc battery chargers with their respective batteries as a backup.On loss of DC input, various inverter malfunctions, or overloads, the static switch will transfer to the alternate AC source. An external manual bypass switch may be used to connect the load directly to the alternate source to allow maintenanceon the inverters.As required by Generic Letter 91-11, which documents the NRCs resolution ofGeneric Issues 48 and 49, plant procedures establish time limitations and surveillance requirements for vital instrument buses and associated inverters.
(References 29 and 30).FOR ADMINISTRATIVE USE ONLYResp Supv:CNSTPAssoc Ref:SR:2yrsNFreq:USAR-MANARMS:USAR-08.07Doc Type:Admin Initials:Date:970305-415 Revision 22USAR 8.7MONTICELLO UPDATED SAFETY ANALYSIS REPORTPage 2 of 2I/mab8.7.2.2Non-Class 1E SystemThe system is composed of a single module UPS to provide an uninterruptiblepower source primarily to the VAX computer systems. The UPS (Y91) issupplied AC by Load Center 108 with an alternate 480 Vac source from Load Center 107. The 250 Vdc backup is provided to UPS Y91 by No. 17 250 Vdc battery through distribution panel D71. UPS Y91 supplies a 3-phase 480 Vac distribution panel Y94 and also 120/208 Vac distribution panels Y90, Y96,PDS1 and PDS2 through 480 - 120/208 Vac transformers. A single linediagram of the system is shown on Figure 8.7-2.During normal conditions, 480 Vac power is supplied to the rectifier/inverter unitby Load Center 108. On loss of 480 Vac input, the No. 17 battery will supply the power required by the inverter to the loads and on a UPS failure the staticswitch will transfer the load to the alternate source, LC 107.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of10SECTION8PLANTELECTRICALSYSTEMSI/arb8.8ElectricalDesignConsiderations8.8.1DivisionSeparationThedesignandinstallationofcablesandracewaysforthereactorprotectionandengineeredsafeguardsystemsprovidesprotectionandseparationofwiringfor redundantchannelsadequatetoachieveanindependenceoffunctionwhichis compatiblewiththedegreeofsystemandequipmentredundancyinvolved.Thespecificcablesandracewaysinthecategoryforwhichseparationisprovidedincludethoseforcircuitsinvolvedinthecontrol,protection,andsupplyofpowertothereactorprotectionandengineeredsafeguardssystems.Circuits relatedtothesesystems,butforwhichseparationisnotnecessarilyprovided, includecablesandracewaysforinstrumentationandalarmswhichhave informationsignificanceonly,andwhichdonotinvolveautomaticcontrolfunctionsofanykind.Furthermore,separationisnotnecessarilyprovidedforpowercircuitswheretheparticularsystemisfail-safeonlossofpower.Forthosecircuitswhichareinthecategoryrequiringseparation,controlwiring fromthesensorstothelogicdevicesandtothefinalcontrolledelement,and powerwiringfromthesource,throughthecontrollertotheloadapparatus,areroutedsothattheredundantchannelsarephysicallyseparatedbyspaceorbybarriers.Cablesforthereactorprotectionsystemareroutedinacompletelyenclosedmetallicracewaysystemcomposedofrigidsteelconduit,steelboxes, andfittings,steelguttersorcoveredsteeltrays.Thisracewaysystemcontains nocircuitsotherthanfortheprotectionsystem,andprovidescompleteseparationofredundantchannels.Cablesforengineeredsafeguardcircuitsare routedintraysand/orconduitswhichprovideadequateseparationofredundant channels.Controlapparatus,distributionequipment,andpowersourcesare alsoseparated.Thedieselgenerators,essential4160Vacand480Vac switchgear,480VacMCC's,andthestationbatteriesareinseparateareasisolatedbyconcretefloorsorwalls.Controlroompanelscontainingdevicesforredundantchannelsareprovidedwithsteelbarriersseparatingthechannelsor redundantsystemsareseparatedby3feetormore.Localpanelsprovide equivalentseparation.Theplantarrangementissuchthatintheturbine-generatorbuilding,whichhousestheessential4160Vacswitchgear,480Vacloadcenters,and480VacMCCswiththeexceptionofMCCs134and144,theapparatusandconnecting racewaysassociatedwitheachredundantchannelarelocatedondifferentlevels separatedbyareinforcedconcretefloor.Thetwodiesel-generatorsarelocatedinseparateroomsabuttingtheturbine-generatorbuilding.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of10I/arbConnectionsfromthediesel-generators,andrelatedequipment,totheapparatusorracewaysintheturbine-generatorbuildingareinrigidsteelconduitswhicharealsoseparatedfromtheredundantchannelbytheconcretefloor.Wheretheracewaysapproachthecablespreadingroom,thetraysofoppositechannels,ofnecessity,approacheachothermorecloselyand separationhereisprovidedbywallsandbarriers.MCCs134and144arelocatedondifferentfloorsoftheEFTbuildingandareseparatedbyaconcretefloor.Insidethecablespreadingroomseparationisprovidedbyhorizontalorverticalspacingoftheracewaysand/orbytheuseofmetallicbarriers.Inthereactorbuildingwhereracewaysapproachthecablespreadingroomaconcreteblockwallseparatestraysoftheoppositedivision.Inthebalanceofthereactorbuilding,separationisprovidedbyspace,barriers,structures,or combinationsthereof.Exceptforthereactorprotectionsystemwhichhasitsownracewaysystem,thesafeguardcablesarenotseparatedfromnon-safeguardcables.Separationis onlyprovidedbetweencablesinonechannelfromtheirredundantcounterpartsintheotherchannel.TofacilitateidentificationofsafeguardchannelstheredundantsystemsareclassifiedasDivisionsIandII.ApparatusrelatedtothesedivisionsaregenerallyidentifiedAandBoroddandevenrespectively.
Theodd-evendesignationappliesparticularlytothepowersources,switchgear, anddistributionapparatusrelatedtotheredundantpowersystems.Racewaysarealsonumberedodd-even.Generallytheoddracewaysareroutedtotheareasoccupiedbytheodd,DivisionIorAequipment,andtheevenracewaysto theeven,DivisionIIorBequipment.Theseparationoftheoddandeven racewaysinmostcases,isequaltoorbetterthantheminimumdescribed previously.Incongestedareassuchasthecablespreadingroomsomeoddandeventraysareofnecessitymuchcloserthantheminimumallowancebythecriteria.Where thisoccursthesetraysareusedonlyfornon-safeguardcables.Thesafeguard cablesareonlyroutedintrayswhereadequateseparationexists.AlthoughmostDivisionIsafeguardcablesareroutedinoddnumberedracewaysandDivisionIIcablesinevenraceways,thereareoccasionswherethisisnot true.TherearealsopossiblesituationswhereDivisionIandIIcablesoccupy thesameraceway.Thiswouldoccurrarelyandwouldonlyinvolvecablesof unrelatedsystemsandnottheredundantcounterpartsrelatedtothesameprotectivefunction.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of10I/arb8.8.2OriginalSeparationCriteriaForThePrimaryContainmentIsolationSystem(PCIS)andtheEngineeredSafeguardsSystemsTheoriginalseparationrequirementsforthePCISandEngineeredSafeguardsSystemsareshownbelow.Separationrequirementsformissileandfirehazards arestatedintermsofdistance.Theseparationstandardallowsforcloser spacingwheresuitablefireandmissilebarriersexist.a.MechanicalDamage(MissileZone)Thesearezonesofpotentialmissiledamageinthevicinityoflarge rotatingapparatusorhighpressurepiping.Inthesezonesracewaysare separatedbyatleast20feetorbya6inchthickreinforcedconcretewall orfloor.Anexceptiontothisrequirementisinsidethedrywellwhere limitedspace,insomecases,preventsattainmentoftheminimum.Wherethisoccurscareistakentolocatetheredundantracewayssothatasinglemissilewillnotdamagebothchannels.b.FireHazardZoneTypeI.Theseareareaswhereoilorothercombustiblesarepresentin largequantitieswhichcouldsupportadamagingfire.Theroutingofracewaysthroughthesezonesisavoidedwhereverpracticable.Whereitisnecessarytorouteracewaysthroughsuchareasonlythoseforone divisionoftheengineeredsafeguardcablesarelocatedtherein.No cablesareroutedthroughtheturbineoilstorageroom.TypeII.Theseareareaswheretheonlysourceoffireisofanelectricalnatureandcombustiblematerialsconsistprimarilyofelectricalinsulation.Intheseareastraysoftheoppositedivisionareseparatedbyatleast3feethorizontallyor5feetverticallyforstackedtrays.Whena3foot horizontalseparationisnotattainablefireresistantbarriersareprovided betweenthetwotrays.Wheretraysarestackedandmeetthe5footseparationrequirement,thetoptrayisalsoprovidedwithasolidsteelbottomandthebottomtraywithasolidsteelcover.Whentraysof oppositedivisionscrosstheseparationmaybereducedto18inches providedthetraytopandbottomcoversextend5feetormoreeachside ofthecrossing.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of10I/arbc.CableSpreadingRoomThisistheroombelowthemaincontrolroomandcontainscabletrays,conduits,gutters,andboxesusedtoroutecablespassingthroughtheroom,andcablesroutedtothecontrolroomboardsabove.Thecable spreadingroomalsohousesanumberofcontrolorrelaypanelsand instrumentACdistributionpanels.Thecriteriafortrayseparationof3foot horizontally,5footvertically,18inchesatcrossingswithtraybottomsandtopscoveredaspreviouslydescribed,isappliedherealso.Wheretraysofoppositedivisionapproachmorecloselythan3foothorizontally,afire resistantbarrierbetweenthetraysisprovided.Cablesleavingtraysof oppositedivisionsandwhichapproacheachothermorecloselythan3 footarebothruninseparatesteelconduitsorenclosedgutters.d.ControlRoomPanelsNosinglecontrolroompanel(orlocalpanelorinstrumentrack)includes wiringforbothDivisionIandIIunlessthefollowingseparation requirementsaremet.Iftwopanelscontainingcircuitsofdifferentdivisionsarelessthan3feetapart,afirebarriershallbebetweenthetwopanels.Panelendsclosedinsteelendplatesareacceptableaslongasthedivisionalterminalboards andwirewaysareoneinchfromtheplate.Floortopanelbarriersare providedbetweenadjacentpanelshavingclosedends.Apanelmaycontainwiringandcomponentsoftwoengineeredsafeguardssystemsredundanttoeachotherprovidedthatthepanelissubdividedbymeansofafirebarrier.Nocableterminalblocksorother componentsshouldbelocatedlessthanoneinchfromsuchabarrier.
Penetrationofseparationbarrierswithinasubdividedpanelispermitted providedthatsuchpenetrationsaresealedorotherwiseratedsothatan electricalfirecouldnotreasonablypropagatefromonesectiontotheotheranddestroytheprotectivefunction.Incaseswherecircuitsandcomponentssuchasmanualswitches,indicatinglights,andannunciatorsarenotvitaltotheautomaticoperation ofredundantsafetysystems,thesecircuitsandcomponentsmaybe groupedtogetheronthesamecontrolroompanel.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of10I/arb8.8.3FunctionalSeparationInadditiontoprovidingchannelseparationasdescribedabove,theracewaysystemprovidesseparationbyfunctionasfollows:1.MediumVoltagePower13.8KVand4160Vacpowercablesareroutedinconduitsortraysseparatefromthoseforcablesofotherfunctions.2.LowVoltagePowerandControlThisclassificationincludescableswithinsulationratedat600Vacusedfor powerandcontrolcircuitsoperatedat480Vacand120Vacandat125Vdc and250Vdc.Powerandcontrolcablesarenotseparatedfromeachother.Racewaysconsistofladdertypetraysandrigidsteelconduit.3.SignalandInstrumentationCablesofthiscategoryareusedincircuitswhichoperateatverylow energylevelsandwhichmaybenoisesensitivebutwhicharenotnoiseproducers.Racewaysareselectedtominimizenoisepickupandconsistof solidbottomsteeltrayswithsolidcoversorrigidsteelconduit.The instrumentationcablesarenotroutedinthesameracewaysaspowerand controlcables.8.8.4EquipmentIdentificationandConfigurationManagementEquipment,includinglocallymounteddevices,whicharepartofengineered safeguardsystems,isprominentlymarkedwithnameplatesorequivalentmeanswhichuniquelyidentifythemasrequiredbytheplantlabelingandequipmentnumberingprograms.Conduits,cabletrays,boxes,andcablesexceptthosethatarepartoflighting,receptacle,communicationandcomputersystemsareassignedandmarkedwithauniqueidentificationnumber.Thisnumberisgenerallyusedon appropriatedrawings,schedules,listings,andconstructionrecordsandcontrols.Cablesaremarkedattheirends.Theracewayandcablenumberingsystemincorporatesanodd-evensignificancetoaidthedesignerinprovidingtheproperseparationofcablesinredundantsafeguardsystems.Strictadministrativecontrolscombinedwiththeproperusageofthedesigndrawings,schedules,andlistingsandtheidentificationmarkingofequipment, raceways,andcablesfacilitatesafetyduringplantoperationandmaintenance.Followingaredescribedanddiscussedtheprincipaldesigndocumentswhichprovidetheinformationnecessarytotheimplementationoftheadministrative controls.a.ConduitandTrayDrawings-Thesedrawingsidentifyandshowthephysicallocationofelectricalraceways,equipmentanddevicestowhichelectricalconnectionsaremade.01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of10I/arbb.Schematic(Elementary)Diagrams-Thesedrawings,inadditiontodefiningcircuitfunction,identifycaseswheremandatoryseparationofsafeguardcablesisrequiredandusually,bymeansoftheodd-evenschemenumber,indicatethesafeguardsdivisionofthesystemtowhicheachcableisrelated.CircuitScheduleThisscheduleincludesforeachcable,thecablenumber,schemenumber,cabletype,andadetailedroutingthroughracewaysfromorigintodestination.RacewaySchedule Thisscheduleincludesforeachraceway,theracewaynumber,type,size,percentfill,andalistingofcablesroutedtherein.ConnectionDiagramsThesedrawingsshowexternalconnectionstomajorapparatusandmostlocaldevices.Thecablenumbers,wirenumbers,andterminalsareshownonthesedrawings.CableListing-SchemeNumberSequenceThecableschedulemaybesortedandgroupedinschemenumbersequence.Referencetothisdocumentandtherelatedschematic(elementary)diagrampermitstheidentificationofcablesassociatedwithaparticularsystem.Further,thislistingmaybeusedtoidentifysafeguardcablesandtheirsafeguarddivision.8.8.5ElectricalPenetrationsTherearevariouscontainment(drywellandwetwell)electricalpenetrationassemblies.Mostarelocatedatnearlythesameelevationandinfourgroups aroundthedrywellperipheryapproximately90oapart.FourassembliesareusedsolelyfortheCRDpositioncables,fourforneutronmonitoringcables,two for4160Vacpowertotherecirculationpumps,oneformiscellaneousthermocouplesandotherlowlevelsignalcircuits,oneforlowlevelsignalcircuits,andthreeformiscellaneouspowerandcontrol.Apparatusordevicesinsidethedrywell,thewiringtowhichrequiresseparation,includeanumberofneutron monitoringcablesassociatedwiththeRPS,severalvalvepositionswitches whichserveasscramsensorsfortheRPS,safeguardcablesrelatedtotheRCIC,RHRandCoreSpraySystems.Althoughonegroupofpenetrationassembliesisseparatedfromtheothersontheexteriorofthedrywellbyconcretewalls,nobarriersexistinsidethedrywell.Separationisprovidedbyvirtueofthespacingofgroupswhichareabout40feet apart.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage7of10I/arbTheneutronmonitoringcablesaredividedintofourchannels.Eachchannelisroutedthroughaseparatepenetrationassembly.Threeoftheseassembliescontainonlyneutronmonitoringcables.Thefourthalsocontainsfourshieldedcablesusedforvibrationdetectorsignalsofextremelylowenergylevel.The fourassembliesarearrangedinpairs,eachpairondiametricallyoppositesides ofthedrywell.Thecablestoandfromeachofthesepenetrations,beinginthe RPSareinstalledincompletelyenclosedracewaysystemsaspreviouslydescribed.Thescramsensorcablesarealsoinfourchannelswhichareroutedthroughtwodiametricallyoppositepenetrationassemblies.Eachassemblycontainstwo groupsofconductorswhichareusedonlyfortheRPScircuits.Eachgroupisseparatedfromtheothergroupandfromotherconductorsinthepenetration assemblybycompleteenclosureinmetallicconduitinsideandoutsidethepenetrationassembly.Theotherconductorsinthesetwopenetration assembliesareusedformiscellaneouspowerandcontrolapplications,including someofthetwo-channelsafeguardservices.Redundantchannelsutilizethediametricallyoppositepenetrationassemblies.8.8.6RacewaysRacewaysofseveraltypesareusedthroughouttheplantfortheroutingofpower,control,andinstrumentcables.Cabletrayisusedforroutingthemain concentrationsofcablesaroundtheplant.Cabletraysaresteelandare manufacturedandtestedinaccordancewithNEMACableTrayStandardsVE-1 (Reference49).Thetraysaredesignedtowithstanda100lb/ftloadingwithdeflectionnotexceeding0.25inchforan8footspan.Traysupportsarespaced8footorcloserandarepredominantlyconstructedofunistrutchannels,inserts andfittings.Traysforpowerandcontrolgenerallyareoftheladdertype.Covers areprovidedwherecablesmaybesubjecttomechanicaldamageorinareas whereuncoveredtraysmighttendtocollectdebris.Traysforinstrumentationaresolidbottom,andprovidedwithcoverstoreduceelectricalnoisepickup.
Solidbottomtrayswithcoversarealsousedforpowerandcontrolcablesin congestedareaswheretheminimumspacingforopentrayscannotbeobtained.
Wheretraysinarunarestacked,theverticalspacingisgenerally1footor greater.Exceptforthesafeguardtrayspreviouslydiscussed,theminimumhorizontalseparationisdeterminedbyaccessibilityrequirementsduringandafterconstruction.Galvanizedrigidsteelconduitisusedforcablesofalltypesroutedfromtraystoapparatusandlocaldevices,andforotherexposedruns.Rigidsteelconduitisalsousedformanyembeddedandundergroundruns.Thinwallconduitisused onlyforlightingandcommunicationscircuits.Shortrunsofflexible,liquid-tight conduitareusedwherevibrationmaybeencounteredortofacilitateremovaloftheconnecteddevice.Fittingsandboxesaremadeofsteel.Someofthe4inchandlargerrunsembeddedinconcretearemadewithplasticconduit.Someundergroundrunsaredirectlyburiedintheearthandareprotectedbyaheavy woodplank.Galvanizedsteelgutterisusedinsomeapplications.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage8of10I/arbWherepractical,conduitfillisheldwithinthepercentagerecommendedbytheNationalElectricalCode(NEC).Trayfillistrackedandcontrolledtolimitexcessiveconcentrationsofheatproducingcablesandexcessivesidewallpressureexertedonindividualcablesbyothercables.8.8.7CablesCablesarequalifiedfortheirspecificapplications.Examplesofcabletypesusedforvariousservicesareasfollows:13.8KV15KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.4160Vac5KVratedshieldedandjacketedpowercablewithcopperPowerCableconductor.600Vac(orOzoneresistantbutylrubberinsulation,neoprenejacket,sizeless)Powerasrequired,No.10AWGminimum.Somepowercablesinside Cablethedrywellusecross-linkedpolyethyleneinsulation.CableswithEPRinsulation,hypalonjacketarealsoused.Feeder cablestoMCC115andMCC124arequalifiedforthespecific undergroundinstallationinvolvedControlMostlymulti-conductorNo.14AWGwith20milsPEinsulation Cableand10milsPVCjacketonthesingles,andPVCjacketoverall.SomeNo.12AWGandNo.10AWGcontrolcablesareused.
SingleconductorcontrolcablewhereusedisNo.10AWGminimumsize.Controlcablesinsidethedrywellandinsomeotherapplicationsusecross-linkedpolyethyleneinsulationwith aneoprenejacket.SpecialAgreatnumberofspecialcablesforparticularapplicationsare Cableused.Followingaresomeofthemorecommontypes:1.CablesformiscellaneousinstrumentationandcomputerusagearePEinsulated,No.16AWG,braidortapeshield, PVCjacketed.Thermocoupleextensionleadsaresimilar.2.Neutronmonitorcablesarecoaxial,tripleshielded,orshieldedpairs,PEinsulation,shields,PVCjacketoverall.3.CRDpositioncablesinsidethedrywellaremulti-conductorNo.20AWG,cross-linkedpolyethylene,neoprenejacket.4.Specialmulti-conductorcontrolapplications,particularlywhereusedwithseparableconnectorsareNo.16toNo.20 AWG,PEorXLPEinsulatedsometimesshielded,PVCjacketoverall.Inselectingconductorsizes,properconsiderationisgiventotheambienttemperatureandtothetypesofracewaysthroughwhichthecableisrouted.Inmostareasoftheplantthedesignambientistakenas40oC(104F).Higherlocaltemperaturesincertainareasarefactoredinasrequired.Insidethedrywellthedesignambienttemperatureis66C(150F).01351154 Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage9of10I/arbForpowercablesinconduitsandtrays,thecablemanufacturer'srecommendations,relevantICEA(formerlyIPCEA)standardsorrelevantindustrystandardsareusedasaguideinselectingtheproperderatingfactor.TheICEAstandardstakesomecreditforadegreeofdiversityintheloadingof thecablesandthefactthatthereareanumberofcontrolcablesandidlepower cableswhichdonotproduceheat.Cableoverloadsarepreventedbytheproperselection,applicationandsettingofprotectiverelays,circuitbreakers,seriestripelementsmotoroverloadheaters,andfuses.Cablesareprotectedagainstdamagefromshortcircuitsbyselectingaconductorwhichwillcarrytheavailablefaultcurrentforthelengthoftimerequiredfortheprotectivedevicetoclearthefault,withoutexceedingthe manufacturer'smaximumshortcircuittemperatureratingfortheconductorinsulation.8.8.8SpecialConsiderationsa.Thenon-safeguardcableinstallationsdonotcompromisethoseprovidedfortheprotectivefunctions.TheRPScablesareintheirownracewaysystemandarenotexposedtocablesofothersystems.Althoughsafeguardcablesandnon-safeguardcablesmayberoutedthroughthesameraceways,thechannelseparationprovidedforthesafeguardcables preventsaccidentsfrominvolvingmorethanoneoftheredundant channels.Thepreviouslydescribedconservativeracewayloading,cable derating,andprotectionagainstelectricalfaults,inconjunctionwiththeassociatedcircuitsanalysis,eliminatesthepossibilityofthesafeguardcablesdescribedinreference6frombeinginvolvedwithfaultsinthenon-vitalcircuits.b.Inconjunctionwiththecomputerprocessedracewayandcircuitschedules,appropriateracewaysandcablesintheplantareassignedanumber.Racewayandcablenumbersincludeanodd-evendesignation,whichgenerallycorrespondstothesystemwithwhichtheyarerelated.
Eachracewayismarkedwithitsidentificationnumber.Thecablenumber isattachedtoeachendofeachcable.Duringthedesignphaseand duringconstructionthecomputerprocessedcircuitandracewayschedulesaretheprimarymeansforcontrollingtheinstallationofRPSandsafeguardcablessothattherequiredchannelseparationisachieved.
Elementarydiagramsorschematicdiagramsforcircuitswhichrequireseparationcarryanotationthatmandatoryseparationoftheredundantfunctionsistobeprovided.Tofacilitatetheroutingseparation,wherepossible,advantageistakenoftheracewaynumberingsystemfor odd-evencables.
Revision30USAR-08.08MONTICELLOUPDATEDSAFETYANALYSISREPORTPage10of10I/arbc.ControlovertheinstallationofcablestoensurethatthedesignrequirementsaremetisprovidedbytheQualityAssuranceProgram.RPSandsafeguardcablesareincludedinthisprogram.Becausesafeguardcablesarenotnecessarilyseparatedfromnon-safeguardcables,racewayscontainingreactorprotection,safeguards,orassociatednon-safeguardscablesareincludedundertheQualityAssurance Program.TheQualityAssuranceProgramassuresthatthecableinstallationshavebeenmadeproperlyandthattheycomplywiththedesignwithrespecttocabletype,identification,routingandconnections, andthattheracewaysareofthecorrecttypesandareproperlyinstalled, andidentified.
SECTION 88.98.9.1
SECTION 88.10
SECTION 88.118.11.1
8.11.2
8.11.3
SECTION 88.12
SECTION 88.13
Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage1of6SECTION8PLANTELECTRICALSYSTEMSI/arbFIGURES Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage2of6I/arbFigure8.3-2LPCISwingBusDegradedPowerTransferSchemeLPCISwingBusDegradedPowerTransferSchemeActuationofanyoftheserelayswillcausetrippingrelay(94P)toopenACB52-3300andcloseACB52-4300.ThistransfersthepowersupplytotheswingbusfromDivisionItoDivsionII.FromDiv.IMCC133A(480V)LPCIInjectionValvesLoopAMCC133BLoadCenter103CoreSprayInjection Valves27-33B27-33A59N-3381-3327-33480/120P.T.ACB52-307(N.C.)ACB52-3300(N.C.)94P(480V)FromDiv.IILoadCenter104ACB52-407(N.C.)ACB52-4300(N.O.)MCC143BMCC143ALPCIInjectionValves LoopBCoreSprayInjectionValvesRelayDesignations27-33A:LossofVoltagewith#11EDGOutputBreakerClosed27-33B:DegradedVoltagewith#11EDGOutputBreakerClosed 59N-33:OverVoltagewith#11EDGOutputBreakerClosed81-33:OutofFrequencywith#11EDGOutputBreakerClosed27-33:LossofNormalVoltage 94P:TrippingRelayTRIPCLOSE Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage3of6I/arbFigure8.4-1DieselGenerationSystemOneLineDiagramToAuxiliaryTransformer(2R) orReserveTransformer(1R)ToReserveAuxiliaryPower Transformer(1AR)No.11DieselGenerator 3125KVA 4.16KV0.80PFNo.12DieselGenerator3125KVA 4.16KV0.80PFToReserveAuxiliaryPower Transformer(1AR)ToAuxiliary Transformer(2R) orReserveTransformer(1R)LC109SPAREBREAKERCIRC.WATERPUMP1250HPLC107LC101TURBINEAUXOILPUMP250HPLC103RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HPCORESPRAYPUMP800HPRHRPUMP600HP*RHRPUMP600HP*INTERTIEFEEDERLC104RHRSERVICEWATERPUMP700HPRHRSERVICEWATERPUMP700HPCRDPUMP250HP CORESPRAYPUMP800HPRHRPUMP600HP*
RHRPUMP600HP*INTERTIEFEEDERLC102LC108CIRCWATERPUMP1250HPSPAREBREAKERSPAREBREAKERBUSNo.13BUSNo.15BUSNo.16BUSNo.14*NOTE:MONTICELLO'SINVENTORYINCLUDESBOTH600AND700HPMOTORSTHATMAYBEUSEDONANYOFTHEFOURRHRPUMPS.01351161 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage4of6I/arbFigure8.5-4#17-250VdcDistributionPanel(D71)01298950 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage5of6I/arbFigure8.7-1InstrumentACandUninterruptibleACDistributionSystemSingleLineDiagram120VAC1120VAC1 Revision30USAR-08.FIGMONTICELLOUPDATEDSAFETYANALYSISREPORTPage6of6I/arbFigure8.7-2Y91UninterruptibleACDistributionSystemSingleLineDiagram13DGC40PDS1Y96C40PDS2FILTERNY96XY96BXY96ANPDS96COMPUTEREQUIPMENT3RDFLOORH&VRM2NDADDITIONOLDH&VRM3RDFLOOREASTELECTRICAL EQUIPMENTRMNPDS1ANPDS1NPDS2ANPDS2XPDS2XPDS1Y94480VACY93MAINTENANCEBYPASSSWITCHY90120/208VACY91UPSD71#17BATTERY 250VDC52-70452-80452-80152-701LC108LC10752-71052-711COMPUTERRMXY90