ML17040A303

OEDO-17-00104 - Barry Quigley, Citizen, Email 2.206 Petition for Byron and Braidwood Units 1 & 2 High Energy Line Break

ML17040A303
Person / Time
Site:	Byron, Braidwood
Issue date:	02/08/2017
From:	Exelon Generation Co
To:	NRC/EDO
References
OEDO-17-00104
Download: ML17040A303 (2)

Text

B/B-FSARAMENDMENT18JANUARY1979QUESTION010.4"Werequirethatthecompartmentbetweenthecontainmentandthesafetyvalvehousewhichhousesthemainsteamlinesandfeedwaterlinesandtheisolationvalvesforthoselines,bedesignedtoconsidertheenviron-mentaleffects(pressure,temperature,humidity)and potentialfloodingconsequencesfromanassumedcrack, equivalenttotheflowareaofasingleendedpiperuptureintheselines.Werequirethatessentialequipmentlocatedwithinthecompartment,including themainsteamisolationandfeedwatervalvesandtheir operatorsbecapableofoperatingintheenvironment resultingfromtheabovecrack.Wealsowillrequirethatifthisassumedcrackcouldcausethestructuralfailureofthiscompartment,thenthefailureshould notjeopardizethesafeshutdownoftheplant.In addition,werequirethattheremainingportionof thepipeinthetunnelbetweenthesafetyvalvehouseandtheturbinebuildingmeettheguidelinesofBranchTechnicalPositionAPCSB3-1."Werequirethatyousubmitasubcompartmentpressureanalysistoconfirmthatthedesignofthepipetunnelconformstoourpositionasoutlinedabove."Werequestthatyouevaluatethedesignagainstthisstaffposition,andadviseusastotheoutcomeof yourreview,includinganydesignchangeswhichmayberequired.Theevaluationshouldincludeaverifica-tionthatthemethodsusedtocalculatethepressure buildupinthesubcompartmentsoutsideofthecon-tainmentforpostulatedbreaksarethesameasthose usedforsubcompartmentsinsidethecontainment.Also,theallowanceforstructuraldesignmargins(pressure)shouldbethesame.Ifdifferentmethodsareused, justifythatyourmethodprovidesadequatedesignmargins andidentifythemarginsthatareavailable.Whenyou submittheresultsofyourevaluation,identifythecomputercodesused,theassumptionsusedformassandenergyreleaserates,andsufficientdesigndata sothatwemayperformindependentcalculations.Thepeakpressureandtemperaturesresultingfromthepostulatedbreakofahighenergypipelocatedincompart-mentsorbuildingsisdependentonthemassandenergy flowsduringthetimeofthebreak.Youhavenotpro-videdtheinformationnecessarytodeterminewhattermi-natestheblowdownortodeterminethelengthoftimeblowdownexists.Foreachpipebreakorleakagecrackanalyzed,providethetotalblowdowntimeandthemech-anismusedtoterminateorlimittheblowdowntimeof B/B-FSARAMENDMENT18JANUARY2979flowsothattheenvironmentaleffectswillnotaffectsafeshutdownofthefacility."RESPONSEQualificationtestshavebeenconductedforthecomponentsinthesafetyvalvehouse.Thecomponentsincludethemain steamandmainfeedwaterisolationvalves,themainsteam power-operatedreliefvalve,andthemainsteamsafetyvalves.

Thesetestsconservativelyappliedaging,radiation,seismic,andworstcaseenvironmental(temperature,pressure,andhumidity)loadingtothecomponents,andshowedthatloss offunctiondidnotoccur.TheportionofthemainsteamandmainfeedwaterpipeinthetunnelbetweentheSafetyValveHouseandtheTurbineBuildingmeetstheguidelinesofBranchTechnicalPosition APCSB3-1.Aspecialpipewhiprestraintislocatedaround eachpipeasitpassesthroughthewallseparatingtheisola-tionvalveroomfromthemainsteamtunnel.Thisrestraintlimitstheamountofstrainthatcanbetransmittedtotheisolationvalvesfromanypipebreakinthetunneltoa levelwhichwillnotinterferewiththeproperfunctioning oftheisolationvalves.Thesafetyvalveroom,thesteamtunnel,andthecompartmentbetweenthecontainmentandthesafetyvalveroomallhave thesamebasisfordesign.Thesecompartmentshavebeen designedforpressurization,impingementandtemperature asspecifiedinTable3.8-10,loadcombinations8,13,and14.Anassumedpipecrackorbreakinthetunnel,isolationvalveroom,orsafetyvalvehousecannotcausestructural failure.ThesubcompartmentpressurizationanalysisisincludedasAttachmentC3.6totheFSAR.Themethodsusedtocalculatethepressurebuildupandallowanceforstructural designmarginsinsubcompartmentsoutsidethecontainment (AttachmentsA3.6andC3.6)arethesameasthoseusedfor subcompartmentsinsidethecontainment.Q10.4-2