ML22159A361
| ML22159A361 | |
| Person / Time | |
|---|---|
| Site: | Hermes File:Kairos Power icon.png |
| Issue date: | 06/08/2022 |
| From: | Kairos Power |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML22159A359 | List: |
| References | |
| KP-NRC-2206-004 | |
| Download: ML22159A361 (2) | |
Text
KP-NRC-2206-004 Changes to Hermes PSAR Chapter 5 (Non-Proprietary)
PreliminarySafetyAnalysisReport
HeatTransportSystems
KairosPowerHermesReactor 51 Revision0 CHAPTER5 HEATTRANSPORTSYSTEMS 5.1 PRIMARYHEATTRANSPORTSYSTEM 5.1.1 Description Theprimaryheattransportsystem(PHTS)transfersheatfromthereactorcorebycirculatingreactor coolantbetweenthepackedbedoffuelelements(pebbles)andreflectorinthereactorcoreandthe primaryheatrejectionsystem(PHRS)(Section5.2)duringnormaloperations.ThePHTSincludesa primarysaltpump(PSP),aprimaryheatexchanger(PHX),andassociatedpiping.ThePHTSalsoincludes capabilityforprimaryloopauxiliaryheatingtomaintainthereactorcoolantintheliquidphasewhenthe reactorcoreisnotgeneratingheat,andcapabilitytodrainexternalpipingandthePHXtoallow cooldown,inspection,andmaintenance.AprocessflowdiagramofthePHTSisprovidedinFigure5.11.
ThekeydesignparametersforthePHTSareprovidedinTable5.11.
TheprimarysystemfunctionsofthePHTSarenonsafetyrelatedandincludethefollowing:
TransportheatfromthereactorcoretothePHRStosupportnuclearheatgenerationandtransport.
Managethermaltransients(overallthermalbalance)occurringaspartofnormaloperations.
Supportresidualheatremovalfunctionduringnormalshutdown.
Accommodatethermalexpansionofthesystemandcomponentsintransitioningbetweenthe temperatureatassemblyandoperation.
ProvidecapabilitytodrainthePHTS.toreduceparasiticheatlossduringovercoolingtransients.
MaintainthereactorcoolantpressureinthePHXabovethePHRScoolantpressureundernormal operatingortransientconditionsuntilthePHXisdrained.
Supportreactorpowerleveltransitions(rampupandrampdowninpower).
Provideforinserviceinspection,maintenance,andreplacementactivities.
ThePHTSinterfaceswiththereactorthermalmanagementsystem,inertgassystem,tritium managementsystem,inventorymanagementsystem,andtheinstrumentationandcontrolsystem.
ThesesystemsaredescribedinChapters7and9.
ThedesignofthePHTSensuresthatthereactorcoolantismaintainedatapositivepressuredifferential withrespecttothePHRSduringnormaloperationortransientconditions,untilthePHXisdrained.This ensuresthatpotentialreactorcoolantleakagefromthePHXisdrivenintothePHRStomaintaincontrol ofreactorcoolantchemistryandphysicalproperties.
TheprimarycomponentsofthePHTSaredescribedinthefollowingsubsections.
5.1.1.1 ReactorCoolant Thereactorcoolantisachemicallystable,moltenmixtureoffluorine,lithium,andberyllium(Flibe).A descriptionofthereactorcoolantmaterialcomposition,coolantqualityrequirements,Flibeimpurities, andthermophysicalpropertiesisprovidedintheReactorCoolantfortheKairosPowerFluorideSalt CooledHighTemperatureReactorTopicalReportKTTR005(Reference5.11).Thereactorcoolant performssafetyfunctionsassociatedwithreactivitycontrolandfissionproductretention.The compositionofthereactorcoolantalsoenablesthereactorcoretobedesignedwithanegativecoolant temperaturecoefficientofreactivity.Thisprovidesasafetybenefitsupportingreactivitycontrol,low parasiticneutronabsorptionforeffectivefuelutilization,andminimalshorttermandlongterm activationofthecoolantforimprovedoperationsandmaintenance.Thereactorcoolantalsoservesasa fissionproductbarrierprovidingretentionoffissionproductsthatescapethefuelparticleandfuel pebblebarriersforfuelinthereactorcore.Thisadditionalretentioncapabilitycontributestothe