RG1.141 流体系统的安全壳隔离规定 1978

U.S.NUCLEARREGULATORYCOMMISSIONREGULATORYGUIDEOFFICEOFSTANDARDSDEVELOPMENTREGULATORYGUIDE1.141CONTAINMENTISOLATIONPROVISIONSFORFLUIDSYSTEMSA.INTRODUCTIONGeneralDesignCriteria54,55,56,and57ofAppendixA,GeneralDesignCriteriaforNuclearPowerPlants,to10CFRPart50,LicensingofProductionandUtilizationFacilities,requirethatpipingsystemspenetratingprimaryreactorcontainmentbeprovidedwithisolationcapabilitiesthatreflecttheimportancetosafetyofisolatingthesepipingsystems.ThisguidedescribesamethodacceptabletotheNRCstaffforcomplyingwiththeCommission'srequirementswithrespecttocontainmentisolationoffluidsystems.B.DISCUSSIONWorkingGroupANS-56.2oftheAmericanNuclearSocietyStandardsCommitteeANS-50,NuclearPowerPlantSystemsEngineering,haspreparedastandardwhichspecifiestheminimumdesignrequirementsforcontainmentisolationoffluidsystemsthatpenetratetheprimarycontainmentboundaryoflight-water-cooledreactors.ThisstandardwasapprovedbytheAmericanNationalStandardsInstitute(ANSI)CommitteeN18,DesignCriteriaforNuclearPowerPlants,anddesignatedANSIN271-1976,ContainmentIsolationProvisionsforFluidSystems.'*TheprovisionsofANSIN271-1976includeminimumdesign,testing,andmaintenance'requirementsfortheisolationoffluidsystemsthatpenetratetheprimarycontainmentoflight-water-cooledreactors.Requirementsforthedesignandtestingofpowersupplies,qualifyingofClassIEequipment,andthedesignandtestingofprotectionsystemsareoutsidethescopeofthisstandard.TheseareasarenotcompletelycoveredbythereferencesgiveninANSIN271-1976.CopiesmaybeobtainedfromtheAmericanNuclearSociety,555NorthKensingtonAvenue,LaGrangePark,Illinois60525.Thisstandardcontainsrequirementsindicatedbytheverbshallandrecommendationsindicatedbytheverbshould.Therecommendationsaswellastherequirementsofthestandardwereevaluatedwithrespecttoimportancetosafety.Allrecommendationsareconsideredtobeofsufficientimportancetosafetytobeendorsedalongwiththerequirementsgiveninthestandard.C.REGULATORYPOSITIONTherequirementsandrecommendationsforcontainmentisolationoffluidsystemsthatpenetratetheprimarycontainmentoflight-water-cooledreactorsasspecifiedinANSIN271-1976,ContainmentIsolationProvisionsforFluidSystems,aregenerallyacceptableandprovideanadequatebasisforcomplyingwiththepertinentcontainmentisolationrequirementsofAppendixAto10CFRPart50,subjecttothefollowing:1.Section3.6.4ofANSIN271-1976states:Theclosedsystemshallbeleaktestedinaccordancewith5.3ofthisstandardunlessitcanbeshownbyinspectionthatsystemintegrityisbeingmaintainedforthosesystemsoperatingatapressureequaltoorabovethecontainmentdesignpressure.Thisexceptiontosystemleaktestingisalsoapplicabletoclosedsystemsinsidethecontainment.2.Section4.2.3ofANSIN271-1976states:Sealedclosedisolationvalvesareunderadministrativecontrolsanddonotrequirepositionindicationinthecontrolroomforvalvestatus.Sincethecontainmentisolationvalvesarecomponentsofthecontainmentisolationsystem,whichisanengineeredsafety-featuresystem,allpower-operatedvalvesshouldhavepositionindicationinthecontrolroom.USNRCREGULATORYGUIDESCommentsshouldbesenttotheSecretaryoftheCommission.USNuclearReguRegulatoryGuidesareissuedtodescribeandmakeaveilabletothepublicmethodslatoryCommission,Washington,D.C.20555,AttentionDocketingandServiceacceptabletotheNRCstaffofimplementingspecificpartsoftheCommission'sBranch.regulations,todelineatetechniquesusedbythestaffinevaluatingspecificproblemsorpostulatedaccidents,ortoProvideguidancetoapplicants.RegulatoryGuidesTheguidesaeissuedithefollowingtenbroaddivisionsarenotsubstitutesforregulations,andcompliancewiththemisnotrequired.1.PowerReactors6ProductsMethodsandsolutionsdifferentfromthosesetoutintheguideswillbeaccept-2.ResearcharidTestReactors7.Transportationableiftheyprovideabasisforthefindingsrequisitetotheissuanceorcontinuance3.FuelsandMaterialsFacilities8.OccupationalHealthofapermitorlicensebytheCommission.4.EnvironmentalandSiting9.AntitrustReview5.MaterialsandPlantProtection10.GeneralCommentsandsuggestionsforimprovementsintheseguidesareencouragedatalltimes,andguideswillberevised,asappropriate,toaccommodatecommentsandRequestsforsinglecopiesofissuedguideslwhichmaybereproduced)orforplacetoreflectnewinformationorexperience.However,commentsonthisguide,ifmentonanautomaticdistributionlistforsinglecopiesoffutureguidesinspecificreceivedwithinabouttwomonthsafteritsissuance.willbeparticularlyusefulindivisionsshouldbemadeinwritingtotheUS-NuclearRegulatoryCommission.evaluatingtheneedforanearlyrevision.WashingtonD.C20555.AttentionDirector,DivisionofDocumentControlApril19783.Section4.2.5ofANSIN271-1976states:Diversityinmeansofactuationofautomaticisolationvalvesinseriesshouldbeconsideredtoprecludecommonmodefailure.TheNRCstaff'spositionisthatthereshouldbediversityintheparameterssensed(i.e.,typesofisolationsignals)fortheinitiationofcontainmentisolation.4.Section4.4.8ofANSIN271-1976givesgeneraldesignrequirementsforclosedsystems.Inaddition,allbranchlinesandtheirisolationvalvesinclosedsystemsbothinsideandoutsidethecontainmentshouldmeetthedesigncriteriaofSection3.5orSection3.6.7ifthebranchlinesconstituteoneofthecon