ML24026A301
| ML24026A301 | |
| Person / Time | |
|---|---|
| Site: | Hermes File:Kairos Power icon.png |
| Issue date: | 01/26/2024 |
| From: | Kairos Power |
| To: | Document Control Desk |
| Shared Package | |
| ML24026A299 | List: |
| References | |
| KP-NRC-2401-008 | |
| Download: ML24026A301 (1) | |
Text
KP-NRC-2401- 008
Enclosure 1 Changes to Hermes 2 PSAR Chapter 7 (Non-Proprietary)
PreliminarySafetyAnalysisReport InstrumentationandControls
7.2.1.1 ReactorControlSystem TheRCScontrolsandmonitorssystemsandcomponentsthatsupportnormaloperation,planned transients,andnormalshutdownofthereactor.TheRCScontrolsthesystemslistedinFigure7.11and supportsthefollowingcapabilities:
Reactivitycontrolandplannedtransients/adjustmentsinpowerlevel Monitoringofcoreneutronics Pebblehandlingandstorage Monitoringandcontroloftemperatureinthereactor TheRCScontrolsreactivityfornormaloperationsandnormalshutdownusingreactorcontrolelements andreactorshutdownelementsinthereactivitycontrolandshutdownsystem(RCSS)(seeSection4.2).
TheRCSiscapableofincrementallychangingthepositionofreactorcontrolelementsandofreleasing thecontrolandshutdownelements.TheRCSisonlycapableofwithdrawingelementsoneatatimeand theRCSincludesalimitontherateatwhichacontrolelementcanbewithdrawn,asalsodiscussedin Section4.2.2.Inthiswaythedesignprecludes,withmargin,thepotentialforpromptcriticalityand rapidreactivityinsertions.TheRCSinputsincludereactoroutlettemperatureandreactorinlet temperaturesensorsandsourceandpowerrangeneutronexcoredetectors.TheRCSalsoprovidesa reactormonitoringfunctiontomonitorplantcomponentsthatareassociatedwithreactorfunctions.
TheRCSusessourceandpowerrangesensorsthatarelocatedoutsidethereactorvesselforreactor control.
TheRCScontrolspebbleinsertionandextraction,invesselpebblehandling,andexvesselpebble handlinginthepebblehandlingandstoragesystem(PHSS)(seeSection9.3).TheRCSiscapableof countinglinearizedpebblesexternaltothevessel,controllingtherateofpebbleinsertionandremoval fromthevessel,andcontrollingpebbledistributionwithinthePHSS.
TheRCScontrolsthereactorthermalmanagementsystem(RTMS)(seeSection9.1.5)tomonitorthe temperatureoftheprimarysystemtomaintainitwithinthenormaloperatingenvelopeandto implementplannedtransients.TheRCScontrolsexternalheatingelementsintheRTMStoprevent overcooling.
TheRCSprovidesthecapabilityforeventmonitoringandactiveactuationofthedecayheatremoval system(DHRS)(SeeSection6.3.1).
7.2.1.2 ReactorCoolantAuxiliaryControlSystem TheRCACScontrolsandmonitorssystemsandcomponentsthatsupportnormaloperationinthecore.
Thesystemsupportsthefollowingcapabilitiesinthecore:
Chemistrycontrolintheprimarysystem Highlightedtextwaspreviouslychanged.
Inventorymanagementsystemcontrol Submittedon1324(ML24003A766).
Inertgassystemcontrolintheprimaryloops Tritiummanagementsystemmonitoringandcontrol Remotehandlingmaintenanceandinspectionsystemmonitoringandcontrol TheRCACScontrolsthechemistrycontrolsystem(seeSection9.1.1)tomonitorreactorcoolant chemistry.Themonitoringsystemsprovideinformationtofacilitatemaintainingcoolantpurityand circulatingactivitywithinspecificationsforthesystem.
KairosPowerHermes2,Units1and2 77 Revision0 PreliminarySafetyAnalysisReport InstrumentationandControls
Thechilledwatersystem,asdiscussedinSection9.7.4,iscontrolledandmonitoredtosupplycooling watertononsafetyrelatedSSCs.
Theelectricalsupply,asdiscussedinChapter8,iscontrolledandmonitoredtosupportthenonsafety relatednormalandbackuppowersupply.
TheRBHAVACiscontrolledandmonitoredtosupplyreactorbuildingHVAC,asdiscussedinSection9.2.
Theenvironmentalmonitoringsystem,asdiscussedinSection11.1.7,monitorsradiationlevelsin Highlightedtextwas unrestrictedareasandradioactivematerialineffluents. previouslychanged.
Submittedon1324 7.2.2 DesignBases(ML24003A766).
ConsistentwithPrincipalDesignCriteria(PDC)13,thePCSisdesignedtomonitorvariablesandsystems overtheiranticipatedrangesfornormaloperation,andovertherangedefinedinpostulatedevents.
7.2.3 SystemEvaluation ThePCSisdesignedtomonitorplantandunitparametersandmaintainsystemswithinnormal operatingrange.ThePCSisalsodesignedtocontrolplannedtransientsassociatedwithanticipated operationaloccurrencesandmaintaintheaffectedreactorinashutdownstate.Thesefunctionsare consistentwithPDC13.ThePCSdoesnotperformasafetyrelatedfunction.Finally,thePCSisdesigned sothatitcannotinterferewiththeRPSsabilitytoperformitssafetyfunctions;seeSection7.3formore informationabouttheisolationoftheRPSfromthePCS.
ThePCSisadigitalsystemthatcontrolsthereactorpoweraboutapointsetbytheoperator.Thecontrol systemuseslinearaveragetemperatureandflowrateintheprimarysystemasvariableinputsto controlpowerlevelsothatitremainswithinthenormaloperatingenvelope.ThePCScontrolselectrical powergenerationaboutapointsetbytheoperatorsusingsteamflowrates,feedwaterflowrates,and feedwatertemperaturesasinputstocontrolthepositionsofturbinecontrolvalves,turbinebypass valves,andfeedwaterregulatingvalvestobalancetheturbineloadfromeachunit.Thesystemdesign meetstheapplicableportionsInternationalElectrotechnicalCommission(IEC)standard61131for industrialcontrollers(Reference1),andtheapplicableportionsofthecybersecuritystandardIEC62443 (Reference2).Table7.22listsotherstandardsappliedtothePCS.ApplicableportionsofIEEE1012 2017(Reference3)areusedforverificationandvalidationofPCScomponents,whichisconsistentwith thenonsafetyrelatedclassificationofthePCS.
ActioninthePCSisdesignedtoaccuratelyandreliablyprovidecontrolsignalforallmodesofnormal operation.ThePCSisalsodesignedtoprovidetimelycontrolsignals,withfurtheranalysisoftimeliness tobeprovidedinanapplicationfortheOperatingLicense.
ThePCSincludesinterlocksandinhibitsthatprohibitorrestrictoperationofthereactor,PHSS,andthe powergenerationsystemunlesscertainoperatingconditionsaremet.Thefollowinginterlocksare includedinthecontrolsystemdesign:
Aninterlockthatprohibitsreactivitycontrolelementwithdrawaluntilthereissufficientneutron countratetoensurethatnuclearinstrumentsarerespondingtoneutrons.
Interlocksarealsoprovidedrelatedtostartuppowerlevelandpebblehandlingasdetailedin Table7.23.
Aninterlockthatpreventstheopeningofaunitsmainsteamisolationvalvefollowingareactor tripuntilthereissufficientsteamproductiontoensurethataturbineimbalancewillnotoccur.
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